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DWPF GLASS BEADS AND GLASS FRIT TRANSPORT DEMONSTRATION

Energy Technology Data Exchange (ETDEWEB)

Adamson, D; Bradley Pickenheim, B

2008-11-24

DWPF is considering replacing irregularly shaped glass frit with spherical glass beads in the Slurry Mix Evaporator (SME) process to decrease the yield stress of the melter feed (a non-Newtonian Bingham Plastic). Pilot-scale testing was conducted on spherical glass beads and glass frit to determine how well the glass beads would transfer when compared to the glass frit. Process Engineering Development designed and constructed the test apparatus to aid in the understanding and impacts that spherical glass beads may have on the existing DWPF Frit Transfer System. Testing was conducted to determine if the lines would plug with the glass beads and the glass frit slurry and what is required to unplug the lines. The flow loop consisted of vertical and horizontal runs of clear PVC piping, similar in geometry to the existing system. Two different batches of glass slurry were tested: a batch of 50 wt% spherical glass beads and a batch of 50 wt% glass frit in process water. No chemicals such as formic acid was used in slurry, only water and glass formers. The glass beads used for this testing were commercially available borosilicate glass of mesh size -100+200. The glass frit was Frit 418 obtained from DWPF and is nominally -45+200 mesh. The spherical glass beads did not have a negative impact on the frit transfer system. The transferring of the spherical glass beads was much easier than the glass frit. It was difficult to create a plug with glass bead slurry in the pilot transfer system. When a small plug occurred from setting overnight with the spherical glass beads, the plug was easy to displace using only the pump. In the case of creating a man made plug in a vertical line, by filling the line with spherical glass beads and allowing the slurry to settle for days, the plug was easy to remove by using flush water. The glass frit proved to be much more difficult to transfer when compared to the spherical glass beads. The glass frit impacted the transfer system to the point
DWPF GLASS BEADS AND GLASS FRIT TRANSPORT DEMONSTRATION

International Nuclear Information System (INIS)

Adamson, D.; Pickenheim, Bradley

2008-01-01

DWPF is considering replacing irregularly shaped glass frit with spherical glass beads in the Slurry Mix Evaporator (SME) process to decrease the yield stress of the melter feed (a non-Newtonian Bingham Plastic). Pilot-scale testing was conducted on spherical glass beads and glass frit to determine how well the glass beads would transfer when compared to the glass frit. Process Engineering Development designed and constructed the test apparatus to aid in the understanding and impacts that spherical glass beads may have on the existing DWPF Frit Transfer System. Testing was conducted to determine if the lines would plug with the glass beads and the glass frit slurry and what is required to unplug the lines. The flow loop consisted of vertical and horizontal runs of clear PVC piping, similar in geometry to the existing system. Two different batches of glass slurry were tested: a batch of 50 wt% spherical glass beads and a batch of 50 wt% glass frit in process water. No chemicals such as formic acid was used in slurry, only water and glass formers. The glass beads used for this testing were commercially available borosilicate glass of mesh size -100+200. The glass frit was Frit 418 obtained from DWPF and is nominally -45+200 mesh. The spherical glass beads did not have a negative impact on the frit transfer system. The transferring of the spherical glass beads was much easier than the glass frit. It was difficult to create a plug with glass bead slurry in the pilot transfer system. When a small plug occurred from setting overnight with the spherical glass beads, the plug was easy to displace using only the pump. In the case of creating a man made plug in a vertical line, by filling the line with spherical glass beads and allowing the slurry to settle for days, the plug was easy to remove by using flush water. The glass frit proved to be much more difficult to transfer when compared to the spherical glass beads. The glass frit impacted the transfer system to the point
Glass frits coated with silver nanoparticles for silicon solar cells

International Nuclear Information System (INIS)

Li, Yingfen; Gan, Weiping; Zhou, Jian; Li, Biyuan

2015-01-01

Graphical abstract: - Highlights: • Silver-coated glass frits for solar cells were prepared by electroless plating. • Gum Arabic was used as the activating agent of glass frits. • Silver-coated glass frits can improve the photovoltaic performances of solar cells. - Abstract: Glass frits coated with silver nanoparticles were prepared by electroless plating. Gum Arabic (GA) was used as the activating agent of glass frits without the assistance of stannous chloride or palladium chloride. The silver-coated glass frits prepared with different GA dosages were characterized by X-ray diffraction (XRD), field emission scanning electron microscopy (FESEM), and thermogravimetric analysis (TGA). The characterization results indicated that silver-coated glass frits had the structures of both glass and silver. Spherical silver nanoparticles were distributed on the glass frits evenly. The density and particle size of silver nanoparticles on the glass frits can be controlled by adjusting the GA dosage. The silver-coated glass frits were applied to silver pastes to act as both the densification promoter and silver crystallite formation aid in the silver electrodes. The prepared silver-coated glass frits can improve the photovoltaic performances of solar cells
Glass frits coated with silver nanoparticles for silicon solar cells

Energy Technology Data Exchange (ETDEWEB)

Li, Yingfen, E-mail: lyf350857423@163.com; Gan, Weiping; Zhou, Jian; Li, Biyuan

2015-06-30

Graphical abstract: - Highlights: • Silver-coated glass frits for solar cells were prepared by electroless plating. • Gum Arabic was used as the activating agent of glass frits. • Silver-coated glass frits can improve the photovoltaic performances of solar cells. - Abstract: Glass frits coated with silver nanoparticles were prepared by electroless plating. Gum Arabic (GA) was used as the activating agent of glass frits without the assistance of stannous chloride or palladium chloride. The silver-coated glass frits prepared with different GA dosages were characterized by X-ray diffraction (XRD), field emission scanning electron microscopy (FESEM), and thermogravimetric analysis (TGA). The characterization results indicated that silver-coated glass frits had the structures of both glass and silver. Spherical silver nanoparticles were distributed on the glass frits evenly. The density and particle size of silver nanoparticles on the glass frits can be controlled by adjusting the GA dosage. The silver-coated glass frits were applied to silver pastes to act as both the densification promoter and silver crystallite formation aid in the silver electrodes. The prepared silver-coated glass frits can improve the photovoltaic performances of solar cells.
Factors influencing the preparation of silver-coated glass frit with polyvinyl-pyrrolidone

Science.gov (United States)

Xiang, Feng; Gan, Weiping

2018-01-01

In this work, a new electroless silver plating method for the synthesis of silver-coated glass frit composite powders with good morphology has been proposed and the polyvinyl-pyrrolidone (PVP) was used the activating agent. It was found that the weight ratio of PVP to glass frit affected the distribution and number of silver nanoparticles. Moreover, the loading capacity of the glass frit, the pH value and reaction temperature could influence the size of the silver nanoparticles and morphology of silver on the surface of glass frit. The as-prepared silver-coated glass frit was used to prepare a silver paste using an optimized process to form silver nanoparticles with uniform size and high density. The silver paste with silver-coated glass frit increased the photovoltaic conversion efficiency of silicon solar cells by 0.271% compared with the silver paste prepared with pure glass frit. The silver nanoparticles can promoted the precipitation of Ag crystallites on the silicon wafer. Therefore, the silver-coated glass frit can further optimize and enhance the electrical performance of solar cells.
Glass Frit Clumping And Dusting

Energy Technology Data Exchange (ETDEWEB)

Steimke, J. L.

2013-09-26

DWPF mixes a slurry of glass frit (Frit 418) and dilute (1.5 wt%) formic acid solution with high level waste in the Slurry Mix Evaporator (SME). There would be advantages to introducing the frit in a non-slurry form to minimize water addition to the SME, however, adding completely dry frit has the potential to generate dust which could clog filters or condensers. Prior testing with another type of frit, Frit 320, and using a minimal amount of water reduced dust generation, however, the formation of hard clumps was observed. To examine options and behavior, a TTQAP [McCabe and Stone, 2013] was written to initiate tests that would address these concerns. Tests were conducted with four types of glass frit; Frit 320, DWPF Frit 418, Bekeson Frit 418 and Multi-Aspirator Frit 418. The last two frits are chemically identical to DWPF Frit 418 but smaller particles were removed by the respective vendors. Test results on Frit Clumping and Dusting are provided in this report. This report addresses the following seven questions. Short answers are provided below with more detailed answers to follow. 1. Will the addition of a small amount of water, 1.5 wt%, to dry DWPF Frit 418 greatly reduce the dust generation during handling at DWPF? a. Yes, a small scale test showed that adding a little water to the frit greatly reduced dust generation during handling. 2. Will the addition of small amounts of water to the frit cause clumping that will impair frit handling at DWPF? a. No, not with Frit 418. Although clumps were observed to form when 1.5 wt% water was mixed with DWPF Frit 418, then compressed and air-dried overnight, the clumps were easily crushed and did not form the hardened material noted when Frit 320 was tested. 3. What is the measured size distribution of dust generated when dry frit is handled? (This affects the feasibility and choice of processing equipment for removing the dust generating fraction of the frit before it is added to the SME.) a. The size distribution for
Glass Frit Clumping And Dusting

International Nuclear Information System (INIS)

Steimke, J. L.

2013-01-01

DWPF mixes a slurry of glass frit (Frit 418) and dilute (1.5 wt%) formic acid solution with high level waste in the Slurry Mix Evaporator (SME). There would be advantages to introducing the frit in a non-slurry form to minimize water addition to the SME, however, adding completely dry frit has the potential to generate dust which could clog filters or condensers. Prior testing with another type of frit, Frit 320, and using a minimal amount of water reduced dust generation, however, the formation of hard clumps was observed. To examine options and behavior, a TTQAP [McCabe and Stone, 2013] was written to initiate tests that would address these concerns. Tests were conducted with four types of glass frit; Frit 320, DWPF Frit 418, Bekeson Frit 418 and Multi-Aspirator Frit 418. The last two frits are chemically identical to DWPF Frit 418 but smaller particles were removed by the respective vendors. Test results on Frit Clumping and Dusting are provided in this report. This report addresses the following seven questions. Short answers are provided below with more detailed answers to follow. 1. Will the addition of a small amount of water, 1.5 wt%, to dry DWPF Frit 418 greatly reduce the dust generation during handling at DWPF? a. Yes, a small scale test showed that adding a little water to the frit greatly reduced dust generation during handling. 2. Will the addition of small amounts of water to the frit cause clumping that will impair frit handling at DWPF? a. No, not with Frit 418. Although clumps were observed to form when 1.5 wt% water was mixed with DWPF Frit 418, then compressed and air-dried overnight, the clumps were easily crushed and did not form the hardened material noted when Frit 320 was tested. 3. What is the measured size distribution of dust generated when dry frit is handled? (This affects the feasibility and choice of processing equipment for removing the dust generating fraction of the frit before it is added to the SME.) a. The size distribution for
Research on Glass Frit Deposition Based on the Electrospray Process

Directory of Open Access Journals (Sweden)

Yifang Liu

2016-04-01

Full Text Available In this paper, the electrospray technology is used to easily deposit the glass frit into patterns at a micro-scale level. First, far-field electrospray process was carried out with a mixture of glass frit in the presence of ethanol. A uniform, smooth, and dense glass frit film was obtained, verifying that the electrospray technology was feasible. Then, the distance between the nozzle and the substrate was reduced to 2 mm to carry out near-field electrospray. The experimental process was improved by setting the range of the feed rate of the substrate to match both the concentration and the flow rate of the solution. Spray diameter could be less at the voltage of 2 kV, in which the glass frit film was expected to reach the minimum line width. A uniform glass frit film with a line width within the range of 400–500 μm was prepared when the speed of the substrate was 25 mm/s. It indicates that electrospray is an efficient technique for the patterned deposition of glass frit in wafer-level hermetic encapsulation.
Influence of milling process in the surface energy of glass tile frits

International Nuclear Information System (INIS)

Tamayo, A.; Rubio, F.; Otero, J. L.; Rubio, J.

2013-01-01

In this work has been studied the influence of the milling process of two ceramic frits used in the ceramic tile industry. Both glass frits were of similar chemical composition changing SiO 2 by 5% of B 2 O 3 and both of them were water or dry milled. Glass frit surfaces were characterized by FT-IR, Karl-Fischer (K-F) titration and Inverse Gas Chromatography at Infinite Dilution (IGC-ID). By K-F titration it was observed that water milled frits presented 28 and 26 OH groups for 100 A 2 if they do not contain or contain boron, respectively. These surface changes are also observed by IGC-ID. Thus, the glass frit without boron and dry milled presented the highest dispersive surface energy (44 mJ.m - 2) and the less acidic constant (0.13 kJ.mol - 1). Both glass frits are amphoteric with acidic and base surface active sites, and that frit without boron presents the higher basicity. Milling process influences in the acid-base surface characteristics of both frits by increasing the basicity for the one without boron and increasing for the other one. This has been assigned to the different location of hydroxyl groups where the higher interaction is the one that does not contain boron and dry milled as K-F results. (Author)
GLASS FABRICATION AND PRODUCT CONSISTENCY TESTING OF LANTHANIDE BOROSHILICATE FRIT X COMPOSITION FOR PLUTONIUM DISPOSITION

Energy Technology Data Exchange (ETDEWEB)

Marra, J

2006-11-21

The Department of Energy Office of Environmental Management (DOE/EM) plans to conduct the Plutonium Disposition Project at the Savannah River Site (SRS) to disposition excess weapons-usable plutonium. A plutonium glass waste form is the preferred option for immobilization of the plutonium for subsequent disposition in a geologic repository. A reference glass composition (Lanthanide Borosilicate (LaBS) Frit B) was developed during the Plutonium Immobilization Program (PIP) to immobilize plutonium in the late 1990's. A limited amount of performance testing was performed on this baseline composition before efforts to further pursue Pu disposition via a glass waste form ceased. Recent FY05 studies have further investigated the LaBS Frit B formulation as well as development of a newer LaBS formulation denoted as LaBS Frit X. The objectives of this present task were to fabricate plutonium loaded LaBS Frit X glass and perform corrosion testing to provide near-term data that will increase confidence that LaBS glass product is suitable for disposal in the Yucca Mountain Repository. Specifically, testing was conducted in an effort to provide data to Yucca Mountain Project (YMP) personnel for use in performance assessment calculations. Plutonium containing LaBS glass with the Frit X composition with a 9.5 wt% PuO{sub 2} loading was prepared for testing. Glass was prepared to support Product Consistency Testing (PCT) at Savannah River National Laboratory (SRNL). The glass was thoroughly characterized using x-ray diffraction (XRD) and scanning electron microscopy coupled with energy dispersive spectroscopy (SEM/EDS) prior to performance testing. A series of PCTs were conducted at SRNL using quenched Pu Frit X glass with varying exposed surface areas. Effects of isothermal and can-in-canister heat treatments on the Pu Frit X glass were also investigated. Another series of PCTs were performed on these different heat-treated Pu Frit X glasses. Leachates from all these PCTs
GLASS FABRICATION AND PRODUCT CONSISTENCY TESTING OF LANTHANIDE BOROSILICATE FRIT X COMPOSITION FOR PLUTONIUM DISPOSITION

Energy Technology Data Exchange (ETDEWEB)

Marra, J

2006-11-15

The Department of Energy Office of Environmental Management (DOE/EM) plans to conduct the Plutonium Disposition Project at the Savannah River Site (SRS) to disposition excess weapons-usable plutonium. A plutonium glass waste form is the preferred option for immobilization of the plutonium for subsequent disposition in a geologic repository. A reference glass composition (Lanthanide Borosilicate (LaBS) Frit B) was developed during the Plutonium Immobilization Program (PIP) to immobilize plutonium in the late 1990's. A limited amount of performance testing was performed on this baseline composition before efforts to further pursue Pu disposition via a glass waste form ceased. Recent FY05 studies have further investigated the LaBS Frit B formulation as well as development of a newer LaBS formulation denoted as LaBS Frit X. The objectives of this present task were to fabricate plutonium loaded LaBS Frit X glass and perform corrosion testing to provide near-term data that will increase confidence that LaBS glass product is suitable for disposal in the Yucca Mountain Repository. Specifically, testing was conducted in an effort to provide data to Yucca Mountain Project (YMP) personnel for use in performance assessment calculations. Plutonium containing LaBS glass with the Frit X composition with a 9.5 wt% PuO{sub 2} loading was prepared for testing. Glass was prepared to support Product Consistency Testing (PCT) at Savannah River National Laboratory (SRNL). The glass was thoroughly characterized using x-ray diffraction (XRD) and scanning electron microscopy coupled with energy dispersive spectroscopy (SEM/EDS) prior to performance testing. A series of PCTs were conducted at SRNL using quenched Pu Frit X glass with varying exposed surface areas. Effects of isothermal and can-in-canister heat treatments on the Pu Frit X glass were also investigated. Another series of PCTs were performed on these different heat-treated Pu Frit X glasses. Leachates from all these PCTs
Microwave melt and offgas analysis results from a Ferro Corporation reg-sign glass frit

International Nuclear Information System (INIS)

Phillips, J.A.; Hoffman, C.R.; Knutson, P.T.

1995-03-01

In support of the Residue Treatment Technology (RTT) Microwave Solidification project, Waste Projects and Surface Water personnel conducted a series of experiments to determine the feasibility of encapsulating a surrogate sludge waste using the microwave melter. The surrogate waste was prepared by RTT and melted with five varying compositions of low melting glass frit supplied by the Ferro Corporation. Samples were melted using a 50% waste/50% glass frit and a 47.5% waste/47.5% glass frit/5% carbon powder. This was done to evaluate the effectiveness of carbon at reducing a sulfate-based surface scale which has been observed in previous experiments and in full-scale testing. These vitrified samples were subsequently submitted to Environmental Technology for toxicity characteristic leaching procedure (TCLP) testing. Two of the five frits tested in this experiment merit further evaluation as raw materials for the microwave melter. Ferro frit 3110 with and without carbon powder produced a crystalline product which passed TCLP testing. The quality of the melt product could be improved by increasing the melting temperature from 900 degrees C to approximately 1150-1200 degrees C. Ferro frit 3249 produced the optimal quality of glass based on visual observations, but failed TCLP testing for silver when melted without carbon powder. This frit requires a slightly higher melting temperature (≥ 1200 degrees C) compared to frit 3110 and produces a superior product. In conjunction with this work, Surface Water personnel conducted offgas analyses using a Thermal Desorption Mass Spectrometer (TDMS) on selected formulations. The offgas analyses identified and quantified water vapor (H 2 O), oxygen (O 2 ) and carbon oxides (CO and CO 2 ), sulfur (S) and sulfur oxides (SO and SO 2 ), and nitrogen (N 2 ) and nitrogen oxides (NO and NO 2 ) that volatilized during glass formation
Characterization of a glass frit free TiCuAg-thick film metallization applied on aluminium nitride

International Nuclear Information System (INIS)

Reicher, R.; Smetana, W.; Adlassnig, A.; Schuster, J. C.; Gruber, U.

1997-01-01

The metallization of aluminium nitride substrates by glass frit free Ti CuAg-thick film pastes were investigated. Adhesion properties of the conductor paste were tested by measuring tensile strength and compared with commercial Cu-thick film pastes (within glass frit). Also numerical analysis of temperature-distribution and thermal extension of metallized aluminium nitride ceramic, induced by a continuous and a pulsed working electronic device were made with a finite element program. (author)
The role of frit in nuclear waste vitrification

International Nuclear Information System (INIS)

Vienna, J.D.; Smith, P.A.; Dorn, D.A.; Hrma, P.

1994-04-01

Vitrification of nuclear waste requires additives which are often vitrified independently to form a frit. Frit composition is formulated to meet the needs of glass composition and processing. The effects of frit on melter feed and melt processing, glass acceptance, and waste loading is of practical interest in understanding the trade-offs associated with the competing demands placed on frit composition. Melter feed yield stress, viscosity and durability of frits and corresponding waste glasses as well as the kinetics of elementary melting processes have been measured. The results illustrate the competing requirements on frit. Four frits (FY91, FY93, HW39-4, and SR202) and simulated neutralized current acid waste (NCAW) were used in this study. The experimental evidence shows that optimization of frit for one processing related property often results in poorer performance for the remaining properties. The difficulties associated with maximum waste loading and durability are elucidated for glasses which could be processed using technology available for the previously proposed Hanford Waste Vitrification Plant
Glass frit bonding with controlled width and height using a two-step wet silicon etching procedure

Science.gov (United States)

Yifang, Liu; Daner, Chen; Liwei, Lin; Gaofeng, Zheng; Jianyi, Zheng; Lingyun, Wang; Daoheng, Sun

2016-03-01

A simple and versatile two-step silicon wet etching technique for the control of the width and height of the glass frit bonding layer has been developed to improve bonding strength and reliability in wafer-level microelectromechanical systems (MEMS) packaging processes. The height of the glass frit bonding layer is set by the design of a vertical reference wall which regulates the distance between the silicon wafer and the encapsulation capping substrate. On the other hand, the width of the bonding layer is constrained between two micro grooves which are used to accommodate the spillages of extra glass frit during the bonding process. An optimized thermal bonding process, including the formation of glass liquid, removal of gas bubbles under vacuum and the filling of voids under normal atmospheric condition has been developed to suppress the formation of the bubbles/voids. The stencil printing and pre-sintering processes for the glass frit have been characterized before the thermal bonding process under different magnitudes of bonding pressure. The bonding gap thickness is found to be equal to the height of the reference wall of 10 μm in the prototype design. The bubbles/voids are found to be suppressed effectively and the bonding strength increases from 10.2 to 19.1 MPa as compared with a conventional thermal annealing process in air. Experimentally, prototype samples are measured to have passed the high hermetic sealing leakage tests of 5 × 10-8 atm cc s-1.
Low-Li2O Frits: Selecting Glasses that Support the Melt Rate Studies and Challenge the Current Durability Model

International Nuclear Information System (INIS)

Peeler, D. K.; Edwards, T. B.

2005-01-01

During the progressive development of the cold cap model (as it applies to a potential melt rate predictive tool), the formation of an Al-Li-silicate phase was identified as an intermediate reaction phase that could possibly hinder melt rate for SB4. To test this theory, six glasses were designed (using Frit 320's composition as the baseline) to maintain a constant 20 wt% sum of alkali content (in frit) by varying Na 2 O to Li 2 O ratios. The Li 2 O concentration ranged from 8 wt% down to 0% in either 2% or 1% increments with the differences being accounted for by an increase in Na 2 O concentration. Although the primary objective of the ''lower Li 2 O'' frits was to evaluate the potential for melt rate improvements, assessments of durability (as measured by the Product Consistency Test (PCT)) were also performed. The results suggest that durable glasses can be produced with these ''lower Li 2 O'' frits should it be necessary to pursue this option for improving melt rate. In addition to the series of glasses to support melt rate assessments, a series of frits were also developed to challenge the current durability model based on the limits proposed by Edwards et al. (2004). Although the ''new'' limits allow access into compositional regions of interest (i.e., higher alkali systems) which can improve melt rate and/or waste loading, there may still be ''additional'' conservatism. In this report, two series of glasses were developed to challenge the ''new'' durability limits for the SB4 system. In the first series, the total alkali of the Frit 320-based glasses (designed to support the melt rate program) was increased from 20 wt% to 21 wt% (in the frit), but the series also evaluated the possible impact of various Na 2 O and Li 2 O mass ratio differences. The second series pushed the alkali limit in the frit even further with frits containing either 22 or 24 wt% total alkali as well as various Na 2 O and Li 2 O mass ratios. The results of the PCT evaluation indicated
Glass-ceramics frits for high mechanical resistance glazes

International Nuclear Information System (INIS)

Gajek, M.; Lis, J.; Partyka, J.; Wojczyk, M.

2004-01-01

The obtaining and application of glass-ceramics frits for glazes were discussed by many authors. This glazes are characterized by raised mechanical parameters and chemical resistance. Factors, that determines crystallization process are initial composition, heat treatment and nucleation agents. The kind of crystalline phases, crystal habit and the content of residual glass phase play the decisive role in the strengthening of the glaze. In this paper are shown results of investigation over controlled crystallization in the ternary systems; Li 2 O-Al 2 O 3 -SiO 2 , CaO-Al 2 O 3 -SiO 2 , ZnO-Al 2 O 3 -SiO 2 , MgO-Al 2 O 3 -SiO 2 , with or without nucleation agents. (author)
Influence of milling process in the surface energy of glass tile frits; Influencia de la molienda en la energia superficial de fritas para esmaltes

Energy Technology Data Exchange (ETDEWEB)

Tamayo, A.; Rubio, F.; Oteo, J. L.; Rubio, J.

2013-05-01

In this work has been studied the influence of the milling process of two ceramic frits used in the ceramic tile industry. Both glass frits were of similar chemical composition changing SiO{sub 2} by 5% of B{sub 2}O{sub 3} and both of them were water or dry milled. Glass frit surfaces were characterized by FT-IR, Karl-Fischer (K-F) titration and Inverse Gas Chromatography at Infinite Dilution (IGC-ID). By K-F titration it was observed that water milled frits presented 28 and 26 OH groups for 100 A{sup 2} if they do not contain or contain boron, respectively. These surface changes are also observed by IGC-ID. Thus, the glass frit without boron and dry milled presented the highest dispersive surface energy (44 mJ.m{sup -}2) and the less acidic constant (0.13 kJ.mol{sup -}1). Both glass frits are amphoteric with acidic and base surface active sites, and that frit without boron presents the higher basicity. Milling process influences in the acid-base surface characteristics of both frits by increasing the basicity for the one without boron and increasing for the other one. This has been assigned to the different location of hydroxyl groups where the higher interaction is the one that does not contain boron and dry milled as K-F results. (Author) 30 refs.
Influence of milling process in the surface energy of glass tile frits; Influencia de la molienda en la energia superficial de fritas para esmaltes

Energy Technology Data Exchange (ETDEWEB)

Tamayo, A.; Rubio, F.; Otero, J. L.; Rubio, J.

2013-06-01

In this work has been studied the influence of the milling process of two ceramic frits used in the ceramic tile industry. Both glass frits were of similar chemical composition changing SiO{sub 2} by 5% of B{sub 2}O{sub 3} and both of them were water or dry milled. Glass frit surfaces were characterized by FT-IR, Karl-Fischer (K-F) titration and Inverse Gas Chromatography at Infinite Dilution (IGC-ID). By K-F titration it was observed that water milled frits presented 28 and 26 OH groups for 100 A{sup 2} if they do not contain or contain boron, respectively. These surface changes are also observed by IGC-ID. Thus, the glass frit without boron and dry milled presented the highest dispersive surface energy (44 mJ.m{sup -}2) and the less acidic constant (0.13 kJ.mol{sup -}1). Both glass frits are amphoteric with acidic and base surface active sites, and that frit without boron presents the higher basicity. Milling process influences in the acid-base surface characteristics of both frits by increasing the basicity for the one without boron and increasing for the other one. This has been assigned to the different location of hydroxyl groups where the higher interaction is the one that does not contain boron and dry milled as K-F results. (Author)
Relaxation of the lower frit loading constraint for DWPF process control

International Nuclear Information System (INIS)

Brown, K.G.

2000-01-01

The lower limit on the frit loading parameter when measurement uncertainty is introduced has impacted DWPF performance during immobilization of Tank 42 Sludge; therefore, any defensible relaxation or omission of this constraint should correspondingly increase DWPF waste loading and efficiency. Waste loading should be increased because the addition of frit is the current remedy for exceeding the lower frit loading constraint. For example, frit was added to DWPF SME Batches 94, 97 and 98 to remedy these batches for low frit loading. Attempts were also made to add frit in addition to the optimum computed to assure the lower frit loading constraint would be satisfied; however, approximately half of the SME Batches produced after Batch 98 have violated the lower frit loading constraint. If the DWPF batches did not have to be remediated and additional frit added because of the lower frit loading limit, then both, the performance of the DWPF process and the waste loading in the glass produced would be increased. Before determining whether or not the lower frit loading limit can be relaxed or omitted, the origin of this and the other constraints related to durability prediction must be examined. The lower limit loading constraint results from the need to make highly durable glass in DWPF. It is required that DWPF demonstrate that the glass produced would have durability that is at least two standard deviations greater than that of the Environmental Assessment (EA) glass. Glass durability cannot be measured in situ, it must be predicted from composition which can be measured. Fortunately, the leaching characteristics of homogeneous waste glasses is strongly related to the total molar free energy of the constituent species. Thus the waste acceptance specification has been translated into a requirement that the total molar free energy associated with the glass composition that would be produced from a DWPF melter feed batch be less than that of the EA glass accounting for

Silica frit formulation for low temperature co-fired ceramic tapes (LTCC)

International Nuclear Information System (INIS)

Nor Hayati Alias; Che Seman Mahmood

2006-01-01

Glassifier agents or so called fluxes could function to lower down the melting temperature of a ceramic material. Two types of silica based glass frits have been formulated to undergo vitrification at temperature lower than 1000 degree C. Frit A powder is composing of 11% Sodium Carbonate, 11% Calcium Oxide,15% Plumbum Oxide and 10% MgO while Frit B is composing of 12% Boron Oxide, 5% Ceria, 11% Sodium Carbonate and 2% Magnesium Oxide as glassifier agent in Silica powder. Two different ceramic slurries were made from a-alumina powder with addition of either Frit A or Frit B and also dispersant, binder and plasticizers, followed by casting into 0.04 mm thickness alumina green tapes. The tapes were then fired at temperature 1000 degree C to burn out plastic binder system and to vitrify the glass frits. Scanning Electron Microscopy (SEM)/EDX techniques were carried out to observe the changes in microstructure of the tape due to vitrication of glass frits. Comparisons were made with alumina green tapes without any glass frit component and with Commercial LTCC DuPont 951 tape. (Author)
TIME-TEMPERATURE-TRANSFORMATION DIAGRAMS FOR THE SLUDGE BATCH 3 - FRIT 418 GLASS SYSTEM

International Nuclear Information System (INIS)

Billings, A.; Edwards, Tommy

2009-01-01

As a part of the Waste Acceptance Product Specifications (WAPS) for Vitrified High-Level Waste Forms defined by the Department of Energy - Office of Environmental Management, the phase stability must be determined for each of the projected high-level waste (HLW) types at the Savannah River Site (SRS). Specifically, WAPS 1.4.1 requires the glass transition temperature (Tg) to be defined and time-temperature-transformation (TTT) diagrams to be developed. The Tg of a glass is an indicator of the approximate temperature where the supercooled liquid converts to a solid on cooling or conversely, where the solid begins to behave as a viscoelastic solid on heating. A TTT diagram identifies the crystalline phases that can form as a function of time and temperature for a given waste type or more specifically, the borosilicate glass waste form. In order to assess durability, the Product Consistency Test (PCT) was used and the durability results compared to the Environmental Assessment (EA) glass. The measurement of glass transition temperature and the development of TTT diagrams have already been performed for the seven Defense Waste Processing Facility (DWPF) projected compositions as defined in the Waste Form Compliance Plan (WCP). These measurements were performed before DWPF start-up and the results were incorporated in Volume 7 of the Waste Form Qualification Report (WQR). Additional information exists for other projected compositions, but overall these compositions did not consider some of the processing scenarios now envisioned for DWPF to accelerate throughput. Changes in DWPF processing strategy have required this WAPS specification to be revisited to ensure that the resulting phases have been bounded. Frit 418 was primarily used to process HLW Sludge Batch 3 (SB3) at 38% waste loading (WL) through the DWPF. The Savannah River National Laboratory (SRNL) fabricated a cache of glass from reagent grade oxides to simulate the SB3-Frit 418 system at a 38 wt % WL for glass
Potter's Industries tests of spherical frit

International Nuclear Information System (INIS)

Graf, P.L.; Rankin, W.N.

1982-01-01

Potter's Industries has been collaborating with Savannah River Laboratory (SRL) concerning application of glass beads in the Defense Waste Processing Facility. Potter's has previously supplied SRL with 2000 lbs of spheroidized Frit 131 for experimental development. Representatives of Potter's Industries visited SRL recently to discuss results of blasting tests and pumpability tests comparing beads to frit. These tests were conducted at their laboratory facilities in New Jersey. Their blasting work suggested speed of cleaning was higher with frit media than with bead media; however, metal-to-oxide removal ratios were also higher with frit media. Fracture rate of beads used in dry blasting tests was excessive. Low fracture rates were found in -80 +200 mesh beads used in wet blasting tests. Blasting with bead media produced a shiny peened surface while frit media produced a dull matte surface. Some frit impregnation was noted in blasting with -20 +80 frit. Pumpability of bead/water slurries was superior to frit/water slurries at 40 wt % concentrations. 4 tables
Analysis of frit by sodium peroxide fusion and flow injection analysis

International Nuclear Information System (INIS)

Walker, N.; Whitaker, M.

1990-01-01

Test runs for the immobilization of radioactive wastes in glass are now underway at the TNX Facility of the Savannah River Site. The wastes are immobilized by the Integrated Defense Waste Processing Facility Melter System (IDMS) process. The IDMS makes a borosilicate glass. To make the glass, certain quantities of boron and silicate must be maintained in the melter. The silicate is added to the melter in a substance called frit. To determine the amount of frit to add, it is necessary to calculate the percent silicate in the frit. The present method of determining the silicate content of frit has yielded inconsistent results. The focus of this project was to develop and implement a new process for determining the silicate content of frit. The author chose to achieve this goal using a colormetric method
Formulation of special glass frit and its use for decontamination of Joule melter employed for vitrification of high level and radioactive liquid waste

International Nuclear Information System (INIS)

Valsala, T.P.; Mishra, P.K.; Thakur, D.A.; Ghongane, D.E.; Jayan, R.V.; Dani, U.; Sonavane, M.S.; Kulkarni, Y.

2012-01-01

Advanced vitrification system at TWMP Tarapur was used for successful vitrification of large volume of HLW stored in waste tank farm. After completion of the operational life of the joule melter, dismantling was planned. Prior to the dismantling, the hold up inventory of active glass product from the melter was flushed out using specially formulated inactive glass frit to reduce the air activity buildup in the cell during dismantling operations. The properties of the special glass frit prepared are comparable with that of the regular product glass. More than 94% of holdup activity was flushed out from the joule melter prior to the dismantling of the melter. (author)
Sludge Batch Variability Study With Frit 418

International Nuclear Information System (INIS)

Johnson, F.; Edwards, T.

2010-01-01

The Defense Waste Processing Facility (DWPF) initiated processing Sludge Batch 6 (SB6) in the summer of 2010. In support of processing, the Savannah River National Laboratory (SRNL) provided a recommendation to utilize Frit 418 to process SB6. This recommendation was based on assessments of the compositional projections for SB6 available at the time from the Liquid Waste Organization (LWO) and SRNL (using a model-based approach). To support qualification of SB6, SRNL executed a variability study to assess the applicability of the current durability models for SB6. The durability models were assessed over the expected Frit 418-SB6 composition range. Seventeen glasses were selected for the variability study based on the sludge projections used in the frit recommendation. Five of the glasses are based on the centroid of the compositional region, spanning a waste loading (WL) range of 32 to 40%. The remaining twelve glasses are extreme vertices (EVs) of the sludge region of interest for SB6 combined with Frit 418 and are all at 36% WL. These glasses were fabricated and characterized using chemical composition analysis, X-ray diffraction (XRD) and the Product Consistency Test (PCT). After initiating the SB6 variability study, the measured composition of the SB6 Tank 51 qualification glass produced at the SRNL Shielded Cells Facility indicated that thorium was present in the glass at an appreciable concentration (1.03 wt%), which made it a reportable element for SB6. This concentration of ThO 2 resulted in a second phase of experimental studies. Five glasses were formulated that were based on the centroid of the new sludge compositional region combined with Frit 418, spanning a WL range of 32 to 40%. These glasses were fabricated and characterized using chemical composition analysis and the PCT. Based on the measured PCT response, all of the glasses (with and without thorium) were acceptable with respect to the Environmental Assessment (EA) reference glass regardless of
A Novel Technique for the Connection of Ceramic and Titanium Implant Components Using Glass Solder Bonding

Directory of Open Access Journals (Sweden)

Enrico Mick

2015-07-01

Full Text Available Both titanium and ceramic materials provide specific advantages in dental implant technology. However, some problems, like hypersensitivity reactions, corrosion and mechanical failure, have been reported. Therefore, the combining of both materials to take advantage of their pros, while eliminating their respective cons, would be desirable. Hence, we introduced a new technique to bond titanium and ceramic materials by means of a silica-based glass ceramic solder. Cylindrical compound samples (Ø10 mm × 56 mm made of alumina toughened zirconia (ATZ, as well as titanium grade 5, were bonded by glass solder on their end faces. As a control, a two-component adhesive glue was utilized. The samples were investigated without further treatment, after 30 and 90 days of storage in distilled water at room temperature, and after aging. All samples were subjected to quasi-static four-point-bending tests. We found that the glass solder bonding provided significantly higher bending strength than adhesive glue bonding. In contrast to the glued samples, the bending strength of the soldered samples remained unaltered by the storage and aging treatments. Scanning electron microscopy (SEM and energy-dispersive X-ray (EDX analyses confirmed the presence of a stable solder-ceramic interface. Therefore, the glass solder technique represents a promising method for optimizing dental and orthopedic implant bondings.
Errors of DWPF frit analysis: Final report

International Nuclear Information System (INIS)

Schumacher, R.F.

1993-01-01

Glass frit will be a major raw material for the operation of the Defense Waste Processing Facility. The frit will be controlled by certificate of conformance and a confirmatory analysis from a commercial analytical laboratory. The following effort provides additional quantitative information on the variability of frit chemical analyses at two commercial laboratories. Identical samples of IDMS Frit 202 were chemically analyzed at two commercial laboratories and at three different times over a period of four months. The SRL-ADS analyses, after correction with the reference standard and normalization, provided confirmatory information, but did not detect the low silica level in one of the frit samples. A methodology utilizing elliptical limits for confirming the certificate of conformance or confirmatory analysis was introduced and recommended for use when the analysis values are close but not within the specification limits. It was also suggested that the lithia specification limits might be reduced as long as CELS is used to confirm the analysis
Special Frits for Direct-On Enamelling of Pipelines

International Nuclear Information System (INIS)

Berdzenishvili, I.; Siradze, M.; Erokhin, V.; Kldiashvili, R.

2010-01-01

The compositions of low-melting zirconium-strontium frits have been developed for direct-on enamelling of pipes. Owing to the given combination of active cations, toxic fluorine and expensive nickel and lithium were eliminated from glass frit compositions. The enamels were subjected to firing by the induction method. In the synthesized enamels, the optimal complex of properties combining high corrosion-resistant and thermo-mechanic indices, adhesive strength and required specifications was realized. These enamels are recommended for testing on pipelines. (author)
The potential impacts of sodium management on Frit Development for Coupled Operations

Energy Technology Data Exchange (ETDEWEB)

Johnson, F. C. [Savannah River Site (SRS), Aiken, SC (United States). Savannah River National Lab. (SRNL); Edwards, T. B. [Savannah River Site (SRS), Aiken, SC (United States). Savannah River National Lab. (SRNL); Peeler, D. K. [Savannah River Site (SRS), Aiken, SC (United States). Savannah River National Lab. (SRNL)

2015-06-10

In this report, Section 2.0 provides a description of sodium management and its impact on the glass waste form, Section 3.0 provides background information on phase separation, Section 4.0 provides the impact of sodium management on SB9 frit development efforts and the results of a limited scoping study investigating phase separation in potential DWPF frits, and Section 5.0 discusses potential technical issues associated with using a phase separated frit for DWPF operations.
New Coating Technique of Ceramic Implants with Different Glass Solder Matrices for Improved Osseointegration-Mechanical Investigations.

Science.gov (United States)

Mick, Enrico; Markhoff, Jana; Mitrovic, Aurica; Jonitz, Anika; Bader, Rainer

2013-09-11

Ceramics are a very popular material in dental implant technology due to their tribological properties, their biocompatibility and their esthetic appearance. However, their natural surface structure lacks the ability of proper osseointegration, which constitutes a crucial process for the stability and, thus, the functionality of a bone implant. We investigated the application of a glass solder matrix in three configurations-consisting mainly of SiO₂, Al₂O₃, K₂O and Na₂O to TZP-A ceramic specimens. The corresponding adhesive strength and surface roughness of the coatings on ceramic specimens have been analyzed. Thereby, high adhesive strength (70.3 ± 7.9 MPa) was found for the three different coatings. The obtained roughness (R z ) amounted to 18.24 ± 2.48 µm in average, with significant differences between the glass solder configurations. Furthermore, one configuration was also tested after additional etching which did not lead to significant increase of surface roughness (19.37 ± 1.04 µm) or adhesive strength (57.2 ± 5.8 MPa). In conclusion, coating with glass solder matrix seems to be a promising surface modification technique that may enable direct insertion of ceramic implants in dental and orthopaedic surgery.
New Coating Technique of Ceramic Implants with Different Glass Solder Matrices for Improved Osseointegration-Mechanical Investigations

Directory of Open Access Journals (Sweden)

Rainer Bader

2013-09-01

Full Text Available Ceramics are a very popular material in dental implant technology due to their tribological properties, their biocompatibility and their esthetic appearance. However, their natural surface structure lacks the ability of proper osseointegration, which constitutes a crucial process for the stability and, thus, the functionality of a bone implant. We investigated the application of a glass solder matrix in three configurations—consisting mainly of SiO2, Al2O3, K2O and Na2O to TZP-A ceramic specimens. The corresponding adhesive strength and surface roughness of the coatings on ceramic specimens have been analyzed. Thereby, high adhesive strength (70.3 ± 7.9 MPa was found for the three different coatings. The obtained roughness (Rz amounted to 18.24 ± 2.48 µm in average, with significant differences between the glass solder configurations. Furthermore, one configuration was also tested after additional etching which did not lead to significant increase of surface roughness (19.37 ± 1.04 µm or adhesive strength (57.2 ± 5.8 MPa. In conclusion, coating with glass solder matrix seems to be a promising surface modification technique that may enable direct insertion of ceramic implants in dental and orthopaedic surgery.
Viscosity of glasses containing simulated Savannah River Plant waste

International Nuclear Information System (INIS)

Plodinec, M.J.

1978-08-01

The viscosity of glass melts containing four simulated sludge types and two frit candidates (Frits 18 and 21) was measured over the temperature range 750 to 1200 0 C. The viscosity of melts made with either frit was reduced by the addition of high iron sludge, unchanged by average sludge, and increased by composite and high aluminum sludge. High aluminium sludge greatly increased the viscosity. Frit 21 (containing 4 wt % Li 2 O substituted for 4 wt % Na 2 O in Frit 18) was clearly better than Frit 18 in terms of its low viscosity. However, further reductions in viscosity are desirable, especially for glasses containing high aluminum sludge. Changing any frit component by 1 wt % did not significantly affect the viscosity of the glasses. Therefore, variability of 1 wt % in any frit component can be tolerated
Potentiality of a frit waste from ceramic sector as raw material to glass-ceramic material production; Potencialidad de un residuo de frita procedente del sector ceramico como materia prima para la produccion de material vitroceramico

Energy Technology Data Exchange (ETDEWEB)

Barrachina Albert, E.; Llop Pla, J.; Notari Abad, M. D.; Carda Castello, J. B.

2015-10-01

This work consists of studying the devitrification capacity of a residue from sodium-calcium frit, using the vitreous powder sintering method, which follows the traditional ceramic processing route, including a specific heat treatment to generate the appearance of crystals from the original glass phase. Initially the frit residue has been characterized by instrumental techniques such as XRF, XRD and DTA/TG. Furthermore, the chemical analysis (XRF) has allowed the prediction of devitrification potentiality of this residue by theoretical approaches represented by Gingsberg, Raschin-Tschetverikov and Lebedeva ternary diagrams. Then, this residue was subjected to traditional ceramic method, by changing the grinding time, the pressing pressure and prepared samples were obtained at different temperatures. In this part, the techniques for measuring particle size by laser diffraction and XRD and SEM to evaluate the generated crystalline phases, were applied. Finally, it has been found that this frit residue works as glass-ceramic precursor, devitrifying in wollastonite crystals as majority phase and without being subjected to the melting step of the glass-ceramic typical method. (Author)
FRIT DEVELOPMENT FOR HIGH LEVEL WASTE SLUDGE BATCH 5: COMPOSITIONAL TRENDS FOR VARYING ALUMINUM CONCENTRATIONS

Energy Technology Data Exchange (ETDEWEB)

Fox, K; Tommy Edwards; David Best; Irene Reamer; Phyllis Workman

2008-08-28

The objective of this study was to experimentally measure the properties and performance of a series of glasses with compositions that could represent Sludge Batch 5 (SB5) as processed at the Defense Waste Processing Facility (DWPF). The data was used to provide recommendations to the Liquid Waste Organization (LWO) regarding blending and washing strategies in preparing SB5 based on acceptability of the glass compositions. These data were also used to guide frit optimization efforts as the SB5 composition was finalized. Glass compositions for this study were developed by combining a series of SB5 composition projections with a group of frits. Three composition projections for SB5 were developed using a model-based approach at Savannah River National Laboratory (SRNL). These compositions, referred to as SB5 Cases B, C and D, projected removal of 25, 50 and 75% (respectively) of the aluminum in Tank 51 through the low temperature aluminum dissolution process. The frits for this study (Frits 530 through 537) were selected based on their predicted operating windows (i.e., ranges of waste loadings over which the predicted properties of the glasses were acceptable) and their potential (based on historical trends) to provide acceptable melt rates for SB5. Six additional glasses were designed to evaluate alternatives for uranium in DWPF-type glasses used for variability studies and some scoping studies. Since special measures are necessary when working with uranium-containing glasses in the laboratory, it is desirable as a cost and time saving measure to find an alternative for uranium to support frit optimization efforts. Hafnium and neodymium were investigated as potential surrogates for uranium, and other glasses were made by simply excluding the radioactive components and renormalizing the glass composition. The study glasses were fabricated and characterized at SRNL. Chemical composition analyses suggested only minor difficulties in meeting the targeted compositions
FRIT DEVELOPMENT FOR HIGH LEVEL WASTE SLUDGE BATCH 5: COMPOSITIONAL TRENDS FOR VARYING ALUMINUM CONCENTRATIONS

International Nuclear Information System (INIS)

Fox, K; Tommy Edwards; David Best; Irene Reamer; Phyllis Workman

2008-01-01

The objective of this study was to experimentally measure the properties and performance of a series of glasses with compositions that could represent Sludge Batch 5 (SB5) as processed at the Defense Waste Processing Facility (DWPF). The data was used to provide recommendations to the Liquid Waste Organization (LWO) regarding blending and washing strategies in preparing SB5 based on acceptability of the glass compositions. These data were also used to guide frit optimization efforts as the SB5 composition was finalized. Glass compositions for this study were developed by combining a series of SB5 composition projections with a group of frits. Three composition projections for SB5 were developed using a model-based approach at Savannah River National Laboratory (SRNL). These compositions, referred to as SB5 Cases B, C and D, projected removal of 25, 50 and 75% (respectively) of the aluminum in Tank 51 through the low temperature aluminum dissolution process. The frits for this study (Frits 530 through 537) were selected based on their predicted operating windows (i.e., ranges of waste loadings over which the predicted properties of the glasses were acceptable) and their potential (based on historical trends) to provide acceptable melt rates for SB5. Six additional glasses were designed to evaluate alternatives for uranium in DWPF-type glasses used for variability studies and some scoping studies. Since special measures are necessary when working with uranium-containing glasses in the laboratory, it is desirable as a cost and time saving measure to find an alternative for uranium to support frit optimization efforts. Hafnium and neodymium were investigated as potential surrogates for uranium, and other glasses were made by simply excluding the radioactive components and renormalizing the glass composition. The study glasses were fabricated and characterized at SRNL. Chemical composition analyses suggested only minor difficulties in meeting the targeted compositions
Frit screening for Rocky Flats ash and sand, slag, and crucible vitrification

International Nuclear Information System (INIS)

Vienna, J.D.; Li, Hong; Darab, J.G.

1997-06-01

Pacific Northwest National Laboratory (PNNL) is developing vitrified waste forms for plutonium-bearing ash and plutonium-bearing sand, slag, and crucible (SS ampersand C) materials from Rocky Flats. Waste forms are to meet product criteria (e.g., safeguard termination limits, storage criteria, and target plutonium loading) and processing constraints (e.g., upper temperature limits, processing time, and equipment compatibility). The target waste form for ash is an agglomerated product, while that for SS ampersand C is a fully encapsulated product. Laboratory scoping studies were conducted on glass formulations from six different glass families: (1) antimony vanadium phosphate, (2) iron vanadium phosphate, (3) tin zinc phosphate, (4) soda-lime silicate, (5) alkali borosilicate, and (6) alkali borate. Glass families were selected due to viscosity behavior in the temperature range of interest (< 800C). Scoping study tests included gradient furnace tests to determine processing range and sintering temperature, thermogravimetric analysis to determine weight loss as a function of temperature, and crucible tests to determine frit compositions tolerance to variations in processing temperature, waste loading, and waste type. The primary screening criterion for the selection of frits for future studies was processing temperature below 400C to minimize the potential for foaming in ash caused by the release of gases (main source of gas is combustion of carbon species) and to minimize processing cycle times. Based on this criterion, glass formulations from the tin zinc phosphate and alkali borosilicate families were selected for future variability testing. Variability testing will include final product evaluation, glass system tolerance to waste loading and composition variation, and identification of parameters impacting time/temperature profiles. Variability testing results will give a final frit formulation for ash and SS ampersand C, and identify key processing parameters
Development of an Alternative Glass Formulation for Vitrification of Excess Plutonium

International Nuclear Information System (INIS)

MARRA, JAMES

2006-01-01

The Department of Energy Office of Environmental Management (DOE/EM) plans to conduct the Plutonium Disposition Project at the Savannah River Site (SRS) to disposition excess weapons-usable plutonium. A plutonium glass waste form is a leading candidate for immobilization of the plutonium for subsequent disposition in a geologic repository. A reference glass composition (Lanthanide Borosilicate (La 2 O 3 -B 2 O 3 -SiO 2 (LaBS))-Frit B) was developed and testing with the LaBS Frit B composition is underway to provide data to support the Yucca Mountain License Application process. The objective of this task was to investigate alternative frit compositions and/or processing conditions that may improve the performance of the reference Frit B-LaBS glass in the repository. The current LaBS Frit B composition was used as the baseline for alternative glass formulation development efforts. A review of the literature and past high actinide concentration glass development efforts was conducted to formulate candidate compositions for testing. Glass science principles were also utilized to determine candidate frit components that may meet task objectives. Additionally, glass processing methods (e.g. slow cooling or induced heat treatment) were investigated as potential means to improve the glass durability and/or minimize fissile material and neutron absorber separation. Based on these analyses, a series of candidate surrogate glasses were fabricated and analyzed. One composition was then selected for fabrication with PuO 2 and subsequently analyzed. A phase equilibrium approach, developed from the assessment of previous high lanthanide glass formulations, was used to recommend modifications to the SRNL Frit B composition. A specific recommendation to increase Ln 2 O 3 content with concurrent reduction of Al 2 O 3 and SiO 2 content proved to be successful in improving the melting behavior and component solubility of the glass. This change moved the formulation from a
Microcolumn high pressure liquid chromatography with a glass-frit nebulizer interface for plasma emission detection

International Nuclear Information System (INIS)

Ibrahim, M.; Nisamaneepong, W.; Caruso, J.

1985-01-01

Microcolumn high pressure liquid chromatography (micro-HPLC) is rapidly gaining recognition as a practical separation tool for organometallic compounds. The use of the inductively coupled plasma (ICP) as a detector for micro-HPLC is studied. Several miniaturized glass-frit nebulizers are investigated as interfaces between the output of the microbore column and the ICP torch. Their performance with aqueous and methanolic solutions is evaluated by direct nebulization and flow injection analysis. The most efficient of these nebulizers is used in the micro-HPLC/ICP study of some Cd, Pb, and Zn organometallic compounds. Detection limits of 1.92 ng of Pb for tetramethyllead and 5.01 ng of Pb for tetraethyllead are obtained and compared with regular HPLC/ICP of these same compounds. Approximately equivalent detection limits were obtained when using a microwave induced plasma as an alternate plasma source
Surface modifications of dental ceramic implants with different glass solder matrices: in vitro analyses with human primary osteoblasts and epithelial cells.

Science.gov (United States)

Markhoff, Jana; Mick, Enrico; Mitrovic, Aurica; Pasold, Juliane; Wegner, Katharina; Bader, Rainer

2014-01-01

Ceramic materials show excellent esthetic behavior, along with an absence of hypersensitivity, making them a possible alternative implant material in dental surgery. However, their surface properties enable only limited osseointegration compared to titanium implants. Within this study, a novel surface coating technique for enhanced osseointegration was investigated biologically and mechanically. Specimens of tetragonal zirconia polycrystal (TZP) and aluminum toughened zirconia (ATZ) were modified with glass solder matrices in two configurations which mainly consisted of SiO2, Al2O3, K2O, and Na2O. The influence on human osteoblastic and epithelial cell viability was examined by means of a WST-1 assay as well as live/dead staining. A C1CP-ELISA was carried out to verify procollagen type I production. Uncoated/sandblasted ceramic specimens and sandblasted titanium surfaces were investigated as a reference. Furthermore, mechanical investigations of bilaterally coated pellets were conducted with respect to surface roughness and adhesive strength of the different coatings. These tests could demonstrate a mechanically stable implant coating with glass solder matrices. The coated ceramic specimens show enhanced osteoblastic and partly epithelial viability and matrix production compared to the titanium control. Hence, the new glass solder matrix coating could improve bone cell growth as a prerequisite for enhanced osseointegration of ceramic implants.

Surface Modifications of Dental Ceramic Implants with Different Glass Solder Matrices: In Vitro Analyses with Human Primary Osteoblasts and Epithelial Cells

Science.gov (United States)

Mick, Enrico

2014-01-01

Ceramic materials show excellent esthetic behavior, along with an absence of hypersensitivity, making them a possible alternative implant material in dental surgery. However, their surface properties enable only limited osseointegration compared to titanium implants. Within this study, a novel surface coating technique for enhanced osseointegration was investigated biologically and mechanically. Specimens of tetragonal zirconia polycrystal (TZP) and aluminum toughened zirconia (ATZ) were modified with glass solder matrices in two configurations which mainly consisted of SiO2, Al2O3, K2O, and Na2O. The influence on human osteoblastic and epithelial cell viability was examined by means of a WST-1 assay as well as live/dead staining. A C1CP-ELISA was carried out to verify procollagen type I production. Uncoated/sandblasted ceramic specimens and sandblasted titanium surfaces were investigated as a reference. Furthermore, mechanical investigations of bilaterally coated pellets were conducted with respect to surface roughness and adhesive strength of the different coatings. These tests could demonstrate a mechanically stable implant coating with glass solder matrices. The coated ceramic specimens show enhanced osteoblastic and partly epithelial viability and matrix production compared to the titanium control. Hence, the new glass solder matrix coating could improve bone cell growth as a prerequisite for enhanced osseointegration of ceramic implants. PMID:25295270
Impact of Spherical Frit Beads on Simulated DWPF Slurries

International Nuclear Information System (INIS)

SMITH, MICHAEL

2005-01-01

It has been shown that the rheological properties of simulated Defense Waste Processing Facility (DWPF) melter feed with the glass former frit as mostly (90 weight percent) solid spherical particles (referred to as beads) were improved as the feed was less viscous as compared to DWPF melter feed that contained the normal irregular shaped frit particles. Because the physical design of the DWPF Slurry Mix Evaporator (SME), Melter Feed Tank (MFT), and melter feed loop are fixed, the impact of changing the rheology might be very beneficial. Most importantly, higher weight percent total solids feed might be processed by reducing the rheological properties (specifically yield stress) of the feed. Additionally, if there are processing problems, such as air entrainment or pumping, these problems might be alleviated by reducing the rheological properties, while maintaining targeted throughputs. Rheology modifiers are chemical, physical, or a combination of the two and can either thin or thicken the rheology of the targeted slurry. The beads are classified as a physical rheological modifier in this case. Even though the improved rheological properties of the feed in the above mentioned DWPF tanks could be quite beneficial, it is the possibility of increased melt rate that is the main driver for the use of beaded glass formers. By improving the rheological properties of the feed, the weight percent solids of the feed could be increased. This higher weight percent solids (less water) feed could be processed faster by the melter as less energy would be required to evaporate the water, and more would be available for the actual melting of the waste and the frit. In addition, the use of beads to thin the feed could possibly allow for the use of a lower targeted acid stoichiometry in the feed preparation process (if in fact acid stoichiometry is being driven by feed rheology as opposed to feed chemistry). Previous work by the Savannah River National Laboratory (SRNL) with the lab
An Assessment of the Sulfate Solubility Limit for the FRIT 418 - Sludge Batch 2/3 System

International Nuclear Information System (INIS)

PEELER, D.K.

2004-01-01

The objective of this report is to establish a ''single point'' sulfate solubility limit or constraint for the Frit 418 - Sludge Batch 2/3 (SB2/3) system. Based on the results of this study, it is recommended that the glass limit in the Product Composition Control System (PCCS) for the Frit 418 - SB2/3 system be set at 0.60 wt%. The new limit has been set based solely on sealed crucible scale data and does not take credit or account for potential volatilization that may occur in the Defense Waste Processing Facility (DWPF) melter. Although the limit is established based on sealed crucible scale tests, supplementary testing using the Slurry-Fed Melt Rate Furnace (SMRF) provides a measure of confidence that applying the 0.6 wt% limit in PCCS will prevent the formation of a salt layer in the melter. The critical data point that was used to define the solubility limit for this system was from a ''spiked'' 30% waste loading (WL) glass targeting 0.65 wt%. The measured content in this glass was 0.62 wt%. Applying the Savannah River Technology Center - Mobile Laboratory (SRTCML) inductively coupled plasma (ICP) atomic emission spectroscopy (AES) uncertainties to establish a solubility limit for the Frit 418 - SB2/3 system of 0.60 wt% (in glass) provides a ''single point'' limit that covers the anticipated WL interval of interest. It is noted that there are glasses above the 0.60 wt% limit that were homogeneous, thus reinforcing the theory of a compositional effect on solubility within this specific system. In general, higher solubilities were observed at higher targeted waste loadings
Wetting and surface tension of bismate glass melt

International Nuclear Information System (INIS)

Shim, Seung-Bo; Kim, Dong-Sun; Hwang, Seongjin; Kim, Hyungsun

2009-01-01

Lead oxide glass frits are used widely in the electronics industry for low-temperature firing. On the other hand, one of the low-sintering and low-melting lead-free glass systems available, the bismate glass system, is considered to be an alternative to lead oxide glass. In order to extend the applications of Bi 2 O 3 glasses, this study examined the thermophysical properties of low-melting Bi 2 O 3 -B 2 O 3 -ZnO-BaO-Al 2 O 3 -SiO 2 glass frits with various ZnO/B 2 O 3 ratios. The fundamental thermal properties, such as glass transition temperature and softening point, were examined by differential thermal analysis and a glass softening point determination system. The wetting angles, viscosities and surface tension of the various bismate glasses on an alumina substrate were measured using hot-stage microscopy and the sessile drop method. These thermophysical properties will be helpful in understanding the work of adhesion and the liquid spread kinetics of glass frits.
Surface Modifications of Dental Ceramic Implants with Different Glass Solder Matrices: In Vitro Analyses with Human Primary Osteoblasts and Epithelial Cells

Directory of Open Access Journals (Sweden)

Jana Markhoff

2014-01-01

Full Text Available Ceramic materials show excellent esthetic behavior, along with an absence of hypersensitivity, making them a possible alternative implant material in dental surgery. However, their surface properties enable only limited osseointegration compared to titanium implants. Within this study, a novel surface coating technique for enhanced osseointegration was investigated biologically and mechanically. Specimens of tetragonal zirconia polycrystal (TZP and aluminum toughened zirconia (ATZ were modified with glass solder matrices in two configurations which mainly consisted of SiO2, Al2O3, K2O, and Na2O. The influence on human osteoblastic and epithelial cell viability was examined by means of a WST-1 assay as well as live/dead staining. A C1CP-ELISA was carried out to verify procollagen type I production. Uncoated/sandblasted ceramic specimens and sandblasted titanium surfaces were investigated as a reference. Furthermore, mechanical investigations of bilaterally coated pellets were conducted with respect to surface roughness and adhesive strength of the different coatings. These tests could demonstrate a mechanically stable implant coating with glass solder matrices. The coated ceramic specimens show enhanced osteoblastic and partly epithelial viability and matrix production compared to the titanium control. Hence, the new glass solder matrix coating could improve bone cell growth as a prerequisite for enhanced osseointegration of ceramic implants.
Corrosion testing of a plutonium-loaded lanthanide borosilicate glass made with Frit B.

Energy Technology Data Exchange (ETDEWEB)

Ebert, W. L.; Chemical Engineering

2006-09-30

Laboratory tests were conducted with a lanthanide borosilicate (LaBS) glass made with Frit B and added PuO2 (the glass is referred to herein as Pu LaBS-B glass) to measure the dependence of the glass dissolution rate on pH and temperature. These results are compared with the dependencies used in the Defense HLW Glass Degradation Model that was developed to account for HLW glasses in total system performance assessment (TSPA) calculations for the Yucca Mountain repository to determine if that model can also be used to represent the release of radionuclides from disposed Pu LaBS glass by using either the same parameter values that are used for HLW glasses or parameter values specific for Pu LaBS glass. Tests were conducted by immersing monolithic specimens of Pu LaBS-B glass in six solutions that imposed pH values between about pH 3.5 and pH 11, and then measuring the amounts of glass components released into solution. Tests were conducted at 40, 70, and 90 C for 1, 2, 3, 4, and 5 days at low glass-surface-area-to-solution volume ratios. As intended, these test conditions maintained sufficiently dilute solutions that the impacts of solution feedback effects on the dissolution rates were negligible in most tests. The glass dissolution rates were determined from the concentrations of Si and B measured in the test solutions. The dissolution rates determined from the releases of Si and B were consistent with the 'V' shaped pH dependence that is commonly seen for borosilicate glasses and is included in the Defense HLW Glass Degradation Model. The rate equation in that model (using the coefficients determined for HLW glasses) provides values that are higher than the Pu LaBS-B glass dissolution rates that were measured over the range of pH and temperature values that were studied (i.e., an upper bound). Separate coefficients for the rate expression in acidic and alkaline solutions were also determined from the test results to model Pu LaBS-B glass dissolution
Sinter recrystalization and properties evaluation of glass-ceramic from waste glass bottle and magnesite for extended application

Directory of Open Access Journals (Sweden)

As'mau Ibrahim Gebi

2016-12-01

Full Text Available In a bid to address environmental challenges associated with the management of waste Coca cola glass bottle, this study set out to develop glass ceramic materials using waste coca cola glass bottles and magnesite from Sakatsimta in Adamawa state. A reagent grade chrome (coloring agent were used to modify the composition of the coca cola glass bottle; X-ray fluorescence(XRF, X-ray diffraction (XRD and Thermo gravimetric analysis (TGA were used to characterize raw materials, four batches GC-1= Coca cola glass frit +1%Cr2O3, GC-2=97% Coca cola glass frit+ 2% magnesite+1%Cr2O3, GC-3=95% Coca cola glass frit+ 4%magnesite+1%Cr2O3, GC-4=93%Coca cola glass frit+ 6%magnesite+ 1%Cr2O3 were formulated and prepared. Thermal Gradient Analysis (TGA results were used as a guide in selection of three temperatures (7000C, 7500C and 8000C used for the study, three particle sizes -106+75, -75+53, -53µm and 2 hr sintering time were also used, the sinter crystallization route of glass ceramic production was adopted. The samples were characterized by X-ray diffraction (XRD and Scanning Electron Microscope (SEM, the density, porosity, hardness and flexural strength of the resulting glass ceramics were also measured. The resulting glass ceramic materials composed mainly of wollastonite, diopside and anorthite phases depending on composition as indicated by XRD and SEM, the density of the samples increased with increasing sintering temperature and decreasing particle size. The porosity is minimal and it decreases with increasing sintering temperature and decreasing particle size. The obtained glass ceramic materials possess appreciable hardness and flexural strength with GC-3 and GC-4 having the best combination of both properties.
Waste glass melting stages

International Nuclear Information System (INIS)

Anderson, L.D.; Dennis, T.; Elliott, M.L.; Hrma, P.

1993-04-01

Three different simulated nuclear waste glass feeds, consisting of dried waste and glass frit, were heat treated for 1 hour in a gradient furnace at temperatures ranging from approximately 600 degrees C--1000 degrees C. Simulated melter feeds from the Hanford Waste Vitrification Plant (HWVP), the Defense Waste Processing Facility (DWPF), and Kernforschungszentrum Karlsruhe (KfK) in Germany were used. The samples were thin-sectioned and examined by optical microscopy to investigate the stages of the conversion from feed to glass. Various phenomena were seen, such as frit softening, bubble formation, foaming, bubble motion and removal, convective mixing, and homogenization. Behavior of different feeds was similar, although the degree of gas generation and melt homogenization varied
Decontamination processes for waste glass canisters

International Nuclear Information System (INIS)

Rankin, W.N.

1981-06-01

The process which will be used to decontaminate waste glass canisters at the Savannah River Plant consists of: decontamination (slurry blasting); rinse (high-pressure water); and spot decontamination (high-pressure water plus slurry). No additional waste will be produced by this process because glass frit used in decontamination will be mixed with the radioactive waste and fed into the glass melter. Decontamination of waste glass canisters with chemical and abrasive blasting techniques was investigated. The ability of a chemical technique with HNO 3 -HF and H 2 C 2 O 4 to remove baked-on contamination was demonstrated. A correlation between oxide removal and decontamination was observed. Oxide removal and, thus, decontamination by abrasive blasting techniques with glass frit as the abrasive was proposed and demonstrated
Decontamination processes for waste glass canisters

International Nuclear Information System (INIS)

Rankin, W.N.

1981-01-01

The process which will be used to decontaminate waste glass canisters at the Savannah River Plant consists of: decontamination (slurry blasting); rinse (high-pressure water); and spot decontamination (high-pressure water plus slurry). No additional waste will be produced by this process because glass frit used in decontamination will be mixed with the radioactive waste and fed into the glass melter. Decontamination of waste glass canisters with chemical and abrasive blasting techniques was investigated. The ability of a chemical technique with HNO 3 -HF and H 2 C 2 O 4 to remove baked-on contamination was demonstrated. A correlation between oxide removal and decontamination was observed. Oxide removal and, thus, decontamination by abrasive blasting techniques with glass frit as the abrasive was proposed and demonstrated
Waste glass melting stages

International Nuclear Information System (INIS)

Anderson, L.D.; Dennis, T.; Elliott, M.L.; Hrma, P.

1994-01-01

Three simulated nuclear waste glass feeds, consisting of dried waste and glass frit, were heat treated for 1 hour in a gradient furnace at temperatures ranging from approximately 600 degrees C to 1000 degrees C. Simulated melter feeds from the Hanford Waste Vitrification Plant (HWVP), the Defense Waste Processing Facility (DWPF), and Kernforschungszentru Karlsruhe (KfK) in Germany were used. The samples were thin sectioned and examined by optical microscopy to investigate the stages of the conversion from feed to glass. Various phenomena were seen, such as frit softening, bubble formation, foaming, bubble motion and removal, convective mixing, and homogenization. The behavior of different feeds was similar, although the degree of gas generation and melt homogenization varied. 2 refs., 8 tabs
3D printed glass: surface finish and bulk properties as a function of the printing process

Science.gov (United States)

Klein, Susanne; Avery, Michael P.; Richardson, Robert; Bartlett, Paul; Frei, Regina; Simske, Steven

2015-03-01

It is impossible to print glass directly from a melt, layer by layer. Glass is not only very sensitive to temperature gradients between different layers but also to the cooling process. To achieve a glass state the melt, has to be cooled rapidly to avoid crystallization of the material and then annealed to remove cooling induced stress. In 3D-printing of glass the objects are shaped at room temperature and then fired. The material properties of the final objects are crucially dependent on the frit size of the glass powder used during shaping, the chemical formula of the binder and the firing procedure. For frit sizes below 250 μm, we seem to find a constant volume of pores of less than 5%. Decreasing frit size leads to an increase in the number of pores which then leads to an increase of opacity. The two different binders, 2- hydroxyethyl cellulose and carboxymethylcellulose sodium salt, generate very different porosities. The porosity of samples with 2-hydroxyethyl cellulose is similar to frit-only samples, whereas carboxymethylcellulose sodium salt creates a glass foam. The surface finish is determined by the material the glass comes into contact with during firing.
Decontamination processes for waste glass canisters

International Nuclear Information System (INIS)

Rankin, W.N.

1982-01-01

A Defense Waste Processing Facility (DWPF) is currently being designed to convert Savannah River Plant liquid, high-level radioactive waste into a solid form, such as borosilicate glass. To prevent the spread of radioactivity, the outside of the canisters of waste glass must have very low levels of smearable radioactive contamination before they are removed from the DWPF. Several techniques were considered for canister decontamination: high-pressure water spray, electropolishing, chemical dissolution, and abrasive blasting. An abrasive blasting technique using a glass frit slurry has been selected for use in the DWPF. No additional equipment is needed to process waste generated from decontamination. Frit used as the abrasive will be mixed with the waste and fed to the glass melter. In contrast, chemical and electrochemical techniques require more space in the DWPF, and produce large amounts of contaminated by-products, which are difficult to immobilize by vitrification
Method of manufacturing borosilicate glass solidification products

International Nuclear Information System (INIS)

Tanaka, Tsuneya.

1986-01-01

Purpose: To obtain glass solidification products efficiently in a dry process from medium and high level radioactive liquid wastes discharged from PWR type reactors. Method: Boric acid-containing radioactive liquid wastes generated from primary coolants of PWR type reactors are evaporated to condensate as the pre-treatment. The concentrated liquid wastes are supplied to a drum type rotary kiln. While on the other hand, usual glass frits are introduced into the kiln. The liquid wastes are dried in the rotary kiln, as well as B 2 O 3 and the glass frits in the liquid wastes are combined into glass particles. In this case, since the kiln is rotated, no glass particles are deposited on the wall of the kiln. Then, the glass particles are introduced for melting into a high frequency melting furnace made of metal. The melting temperature is set to 1100 - 1150 deg C. The molten borosilicate glass is recovered from the bottom of the melting furance, contained in a canister and cooled for several hours, and then a cover is welded to the canister. (Ikeda, J.)
THE USE OF DI WATER TO MITIGATE DUSTING FOR ADDITION OF DWPF FRIT TO THE SLURRY MIX EVAPORATOR

Energy Technology Data Exchange (ETDEWEB)

Hansen, E.

2010-07-21

The Defense Waste Processing Facility (DPWF) presently is in the process to determine means to reduce water utilization in the Slurry Mix Evaporator (SME) process, thus reducing effluent and processing times. The frit slurry addition system mixes the dry frit with water, yielding approximately a 50 weight percent slurry containing frit and the other fraction water. This slurry is discharged into the SME and excess water is removed via boiling. To reduce this water load to the SME, DWPF has proposed using a pneumatic system in conveying the frit to the SME, in essence a dry delivery system. The problem associated with utilizing a dry delivery system with the existing frit is the generation of dust when discharged into the SME. The use of water has been shown to be effective in the mining industry as well in the DOE complex to mitigate dusting. The method employed by SRNL to determine the quantity of water to mitigate dusting in dry powders was effective, between a lab and bench scale tests. In those tests, it was shown that as high as five weight percent (wt%) of water addition was required to mitigate dust from batches of glass forming minerals used by the Waste Treatment Plant at Hanford, Washington. The same method used to determine the quantity of water to mitigate dusting was used in this task to determine the quantity of water to mitigate this dusting using as-received frit. The ability for water to mitigate dusting is due to its adhesive properties as shown in Figure 1-1. Wetting the frit particles allows for the smaller frit particles (including dust) to adhere to the larger frit particles or to agglomerate into large particles. Fluids other than water can also be used, but their adhesive properties are different than water and the quantity required to mitigate dusting is different, as was observed in reference 1. Excessive water, a few weight percentages greater than that required to mitigate dusting can cause the resulting material not to flow. The primary
SLUDGE BATCH 4 BASELINE MELT RATE FURNACE AND SLURRY-FED MELT RATE FURNACE TESTS WITH FRITS 418 AND 510 (U)

International Nuclear Information System (INIS)

Smith, M; Timothy Jones, T; Donald02 Miller, D

2007-01-01

Several Slurry-Fed Melt Rate Furnace (SMRF) tests with earlier projections of the Sludge Batch 4 (SB4) composition have been performed.1,2 The first SB4 SMRF test used Frits 418 and 320, however it was found after the test that the REDuction/OXidation (REDOX) correlation at that time did not have the proper oxidation state for manganese. Because the manganese level in the SB4 sludge was higher than previous sludge batches tested, the impact of the higher manganese oxidation state was greater. The glasses were highly oxidized and very foamy, and therefore the results were inconclusive. After resolving this REDOX issue, Frits 418, 425, and 503 were tested in the SMRF with the updated baseline SB4 projection. Based on dry-fed Melt Rate Furnace (MRF) tests and the above mentioned SMRF tests, two previous frit recommendations were made by the Savannah River National Laboratory (SRNL) for processing of SB4 in the Defense Waste Processing Facility (DWPF). The first was Frit 503 based on the June 2006 composition projections.3 The recommendation was changed to Frit 418 as a result of the October 2006 composition projections (after the Tank 40 decant was implemented as part of the preparation plan). However, the start of SB4 processing was delayed due to the control room consolidation outage and the repair of the valve box in the Tank 51 to Tank 40 transfer line. These delays resulted in changes to the projected SB4 composition. Due to the slight change in composition and based on preliminary dry-fed MRF testing, SRNL believed that Frit 510 would increase throughput in processing SB4 in DWPF. Frit 418, which was used in processing Sludge Batch 3 (SB3), was a viable candidate and available in DWPF. Therefore, it was used during the initial SB4 processing. Due to the potential for higher melt rates with Frit 510, SMRF tests with the latest SB4 composition (1298 canisters) and Frits 510 and 418 were performed at a targeted waste loading (WL) of 35%. The '1298 canisters
Chemical reactivity of precursor materials during synthesis of glasses used for conditioning high-level radioactive waste: Experiments and models

International Nuclear Information System (INIS)

Monteiro, A.

2012-01-01

The glass used to store high-level radioactive waste is produced by reaction of a solid waste residue and a glassy precursor (glass frit). The waste residue is first dried and calcined (to lose water and nitrogen respectively), then mixed with the glass frit to enable vitrification at high temperature. In order to obtain a good quality glass of constant composition upon cooling, the chemical reactions between the solid precursors must be complete while in the liquid state, to enable incorporation of the radioactive elements into the glassy matrix. The physical and chemical conditions during glass synthesis (e.g. temperature, relative proportions of frit and calcine, amount of radioactive charge) are typically empirically adjusted to obtain a satisfactory final product. The aim of this work is to provide new insights into the chemical and physical interactions that take place during vitrification and to provide data for a mathematical model that has been developed to simulate the chemical reactions. The consequences of the different chemical reactions that involve solid, liquid and gaseous phases are described (thermal effects, changes in crystal morphology and composition, variations in melt properties and structure). In a first series of experiments, a simplified analogue of the calcine (NaNO 3 -Al 2 O 3 ± MoO 3 /Nd 2 O 3 ) has been studied. In a second series of experiments, the simplified calcines have been reacted with a simplified glass frit (SiO 2 -Na 2 O-B 2 O 3 -Al 2 O 3 ) at high temperature. The results show that crystallization of the calcine may take place before interaction with the glass frit, but that the reactivity with the glass at high temperature is a function of the nature and stoichiometry of the crystalline phases which form at low temperature. The results also highlight how the mixing of the starting materials, the physical properties of the frit (viscosity, glass transition temperature) and the Na 2 O/Al 2 O 3 of the calcine but also its
Decontamination of Savannah River Plant waste glass canisters

International Nuclear Information System (INIS)

Rankin, W.N.

1982-01-01

A Defense Waste Processing Facility (DWPF) is currently being designed to convert Savannah River Plant (SRP) liquid, high-level radioactive waste into a solid form, such as borosilicate glass. The outside of the canisters of waste glass must have very low levels of smearable radioactive contamination before they are removed from the DWPF to prevent the spread of radioactivity. Several techniques were considered for canister decontamination: high-pressure water spray, electropolishing, chemical dissolution, and abrasive blasting. An abrasive blasting technique using a glass frit slurry has been selected for use in the DWPF. No additional equipment is needed to process waste generated from decontamination. Frit used as the abrasive will be mixed with the waste and fed to the glass melter. In contrast, chemical and electrochemical techniques require more space in the DWPF, and produce large amounts of contaminated byproducts which are difficult to immobilize by vitrification
Composition and redox control of waste glasses: Recommendation for process control limit

International Nuclear Information System (INIS)

Jantzen, C.M.; Plodinec, M.J.

1986-01-01

An electrochemical series of redox couples, originally developed for Savannah River Laboratory glass frit 131 (SRL-131) as a reference composition, has been extended to two other alkali borosilicate compositions that are candidate glasses for nuclear waste immobilization. Since no dramatic differences were ascertained in the redox chemistry of selected multivalent elements in SRL-131 versus that in Savannah River Laboratory glass frit 165 (SRL-165) and in West Valley glass number-sign 205 (WV-205), the comprehensive electrochemical series can readily be applied to a range of nuclear waste glass compositions. In order to alleviate potential problems with foaming and precipitation of insolubles during the processing of the nuclear waste in these glass melts, the [Fe 2+ ]/[Fe 3+ ] ratio of the melt should be between 0.1 and 0.5. 27 refs., 4 figs., 2 tabs
Lot No. 1 of Frit 202 for DWPF cold runs

International Nuclear Information System (INIS)

Schumacher, R.F.

1993-01-01

This report was prepared at the end of 1992 and summarizes the evaluation of the first lot sample of DWPF Frit 202 from Cataphote Inc. Publication of this report was delayed until the results from the carbon analyses could be included. To avoid confusion the frit specifications presented in this report were those available at the end of 1992. The specifications were slightly modified early in 1993. The frit was received and evaluated for moisture, particle size distribution, organic-inorganic carbon and chemical composition. Moisture content and particle size distribution were determined on a representative sample at SRTC. These properties were within the DWPF specifications for Frit 202. A representative sample was submitted to Corning Engineering Laboratory Services for chemical analyses. The sample was split and two dissolutions prepared. Each dissolution was analyzed on two separate days. The results indicate that there is a high probability (>95%) that the silica content of this frit is below the specification limit of 77.0 ± 1.0 wt %. The average of the four analyzed values was 75.1 wt % with a standard deviation of 0.28 wt %. All other oxides were within the elliptical two sigma limits. Control standard frit samples were submitted and analyzed at the same time and the results were very similar to previous analyses of these materials

Sludge Batch 5 Slurry Fed Melt Rate Furnace Test with Frits 418 and 550

International Nuclear Information System (INIS)

Miller, Donald; Pickenheim, Bradley

2009-01-01

Based on Melt Rate Furnace (MRF) testing for the Sludge Batch 5 (SB5) projected composition and assessments of the potential frits with reasonable operating windows, the Savannah River National Laboratory (SRNL) recommended Slurry Fed Melt Rate Furnace (SMRF) testing with Frits 418 and 550. DWPF is currently using Frit 418 with SB5 based on SRNL's recommendation due to its ability to accommodate significant sodium variation in the sludge composition. However, experience with high boron containing frits in DWPF indicated a potential advantage for Frit 550 might exist. Therefore, SRNL performed SMRF testing to assess Frit 550's potential advantages. The results of SMRF testing with SB5 simulant indicate that there is no appreciable difference in melt rate between Frit 418 and Frit 550 at a targeted 34 weight % waste loading. Both batches exhibited comparable behavior when delivered through the feed tube by the peristaltic pump. Limited observation of the cold cap during both runs showed no indication of major cold cap mounding. MRF testing, performed after the SMRF runs due to time constraints, with the same two Slurry Mix Evaporator (SME) dried products led to the same conclusion. Although visual observations of the cross-sectioned MRF beakers indicated differences in the appearance of the two systems, the measured melt rates were both ∼0.6 in/hr. Therefore, SRNL does not recommend a change from Frit 418 for the initial SB5 processing in DWPF. Once the actual SB5 composition is known and revised projections of SB5 after the neptunium stream addition and any decants is provided, SRNL will perform an additional compositional window assessment with Frit 418. If requested, SRNL can also include other potential frits in this assessment should processing of SB5 with Frit 418 result in less than desirable melter throughput in DWPF. The frits would then be subjected to melt rate testing at SRNL to determine any potential advantages
Soldering handbook

CERN Document Server

Vianco, Paul T

1999-01-01

Contains information related to soldering processes, and solder joint performance and reliability. Covers soldering fundamentals, technology, materials, substrate materials, fluxes, pastes, assembly processes, inspection, and environment. Covers today's advanced joining applications and emphasizes new materials, including higher strength alloys; predictive performance; computer modeling; advanced inspection techniques; new processing concepts, including laser heating; and the resurgence in ultrasonic soldering.
Design of glass-ceramic complex microstructure with using onset point of crystallization in differential thermal analysis

International Nuclear Information System (INIS)

Hwang, Seongjin; Kim, Jinho; Shin, Hyo-Soon; Kim, Jong-Hee; Kim, Hyungsun

2008-01-01

Two types of frits with different compositions were used to develop a high strength substrate in electronic packaging using a low temperature co-fired ceramic process. In order to reveal the crystallization stage during heating to approximately 900 deg. C, a glass-ceramic consisting of the two types of frits, which had been crystallized to diopside and anorthite after firing, was tested at different mixing ratios of the frits. The exothermal peaks deconvoluted by a Gauss function in the differential thermal analysis curves were used to determine the onset point of crystallization of diopside or anorthite. The onset points of crystallization were affected by the mixing ratio of the frits, and the microstructure of the glass-ceramic depended on the onset point of crystallization. It was found that when multicrystalline phases appear in the microstructure, the resulting complex microstructure could be predicted from the onset point of crystallization obtained by differential thermal analysis
On the problem of soldering refractory metals with silver-containing solders

International Nuclear Information System (INIS)

Anikeev, E.F.; Andryushchenko, V.I.; Chepelenko, V.N.; Batov, V.M.

1981-01-01

The processes of wetting, spreading and interphase interactions of copper-silver liquid alloys alloyed with Ni and Si, with niobium, tantalum, molybdenum, tungsten, 12Kh18N10T steel and nickel are studied. It has been determined that Ni or Si additions into the copper-silver solder improve the wetting and adhesion. When soldering with the alloy containing Ni additions, the strength of a soldered Joint grows with the increase of soldering duration while soldering with the alloy containing Si additions, the strength decreases. That is why Ni-containing solders are preferable for soldering thick-walled structures, and Si-containing solders - for thin-walled structures [ru
Characterization of lead-free solders for electronic packaging

Science.gov (United States)

Ma, Hongtao

The characterization of lead-free solders, especially after isothermal aging, is very important in order to accurately predict the reliability of solder joints. However, due to lack of experimental testing standards and the high homologous temperature of solder alloys (Th > 0.5T m even at room temperature), there are very large discrepancies in both the tensile and creep properties provided in current databases for both lead-free and Sn-Pb solder alloys. In this research, mechanical measurements of isothermal aging effects and the resulting changes in the materials behavior of lead-free solders were performed. A novel specimen preparation procedure was developed where the solder uniaxial test specimens are formed in high precision rectangular cross-section glass tubes using a vacuum suction process. Using specimens fabricated with the developed procedure, isothermal aging effects and viscoplastic material behavior evolution have been characterized for 95.5Sn-4.0Ag-0.5Cu (SAC405) and 96.5Sn-3.0Ag-0.5Cu (SAC305) lead-free solders, which are commonly used as the solder ball alloy in lead-free BGAs and other components. Analogous tests were performed with 63Sn-37Pb eutectic solder samples for comparison purposes. Up to 40% reduction in tensile strength was observed for water quenched specimens after two months of aging at room temperature. Creep deformation also increased dramatically with increasing aging durations. Microstructural changes during room temperature aging were also observed and recorded for the solder alloys and correlated with the observed mechanical behavior changes. Aging effects at elevated temperatures for up to 6 months were also investigated. Thermal aging caused significant tensile strength loss and deterioration of creep deformation. The thermal aging results also showed that after an initial tensile strength drop, the Sn-Pb eutectic solder reached a relatively stable stage after 200 hours of aging. However, for SAC alloy, both the tensile and
SMT soldering handbook

National Research Council Canada - National Science Library

Strauss, Rudolf

1998-01-01

... 3.2.1 Constituents, melting behaviour and mechanical properties 3.2.2 Composition of solders for use in electronics 3.2.3 Lead-free solders 3.2.4 Solder impurities The soldered joint 3.3.1 Solde...
Synthesis of TiCuAg thick film inks for glass frit free metallization of aluminium nitride

International Nuclear Information System (INIS)

Adlassnig, A.; Schuster, J. C.; Smetana, W.; Reicher, R.

1997-01-01

A glas frit free screen printing ink for metallization of AIN was developed. Bonding to the substrate is achieved by active metal additives. The metallic component consists of Cu and Ag powder synthesized from inorganic salts by the polyol process, and Cu-Ti powder synthesized by arc melting, milling and ultracentrifugation. This ternary powder mixture was introduced to a specifically developed organic vehicle and screen printed onto AIN. The detailed development process and the results will be presented. (author)
Soldering in electronics assembly

CERN Document Server

Judd, Mike

2013-01-01

Soldering in Electronics Assembly discusses several concerns in soldering of electronic assemblies. The book is comprised of nine chapters that tackle different areas in electronic assembly soldering. Chapter 1 discusses the soldering process itself, while Chapter 2 covers the electronic assemblies. Chapter 3 talks about solders and Chapter 4 deals with flux. The text also tackles the CS and SC soldering process. The cleaning of soldered assemblies, solder quality, and standards and specifications are also discussed. The book will be of great use to professionals who deal with electronic assem
Microcolumns with self-assembled particle frits for proteomics

DEFF Research Database (Denmark)

Ishihama, Yasushi; Rappsilber, Juri; Andersen, Jens S

2002-01-01

LC-MS-MS experiments in proteomics are usually performed with packed microcolumns employing frits or outlets smaller than the particle diameter to retain the packing material. We have developed packed microcolumns using self-assembled particles (SAPs) as frits that are smaller than the size...... of the outlet. A five to one ratio of outlet size to particle diameter appears to be the upper maximum. In these situations the particles assembled into an arch over the outlet like the stones in a stone bridge. When 3 microm particles were packed into a tapered column with an 8 microm outlet, two particles...
A Glass-Ceramic Waste Forms for the Immobilization of Rare Earth Oxides from the Pyroprocessing Waste salt

International Nuclear Information System (INIS)

Ahn, Byung-Gil; Park, Hwan-Seo; Kim, Hwan-Young; Kim, In-Tae

2008-01-01

The fission product of rare earth (RE) oxide wastes are generates during the pyroprocess . Borosilicate glass or some ceramic materials such as monazite, apatite or sodium zirconium phosphate (NZP) have been a prospective host matrix through lots of experimental results. Silicate glasses have long been the preferred waste form for the immobilization of HLW. In immobilization of the RE oxides, the developed process on an industrial scale involves their incorporation into a glass matrix, by melting under 1200 ∼ 1300 .deg. C. Instead of the melting process, glass powder sintering is lower temperature (∼ 900 .deg. C) required for the process which implies less demanding conditions for the equipment and a less evaporation of volatile radionuclides. This study reports the behaviors, direct vitrification of RE oxides with glass frit, glass powder sintering of REceramic with glass frit, formation of RE-apatite (or REmonazite) ceramic according to reaction temperature, and the leach resistance of the solidified waste forms
Laser soldering of Sn-Ag-Cu and Sn-Zn-Bi lead-free solder pastes

Science.gov (United States)

Takahashi, Junichi; Nakahara, Sumio; Hisada, Shigeyoshi; Fujita, Takeyoshi

2004-10-01

It has reported that a waste of an electronics substrate including lead and its compound such as 63Sn-37Pb has polluted the environment with acid rain. For that environment problem the development of lead-free solder alloys has been promoted in order to find out the substitute for Sn-Pb solders in the United States, Europe, and Japan. In a present electronics industry, typical alloys have narrowed down to Sn-Ag-Cu and Sn-Zn lead-free solder. In this study, solderability of Pb-free solder that are Sn-Ag-Cu and Sn-Zn-Bi alloy was studied on soldering using YAG (yttrium aluminum garnet) laser and diode laser. Experiments were peformed in order to determine the range of soldering parameters for obtaining an appropriate wettability based on a visual inspection. Joining strength of surface mounting chip components soldered on PCB (printed circuit board) was tested on application thickness of solder paste (0.2, 0.3, and 0.4 mm). In addition, joining strength characteristics of eutectic Sn-Pb alloy and under different power density were examined. As a result, solderability of Sn-Ag-Cu (Pb-free) solder paste are equivalent to that of coventional Sn-Pb solder paste, and are superior to that of Sn-Zn-Bi solder paste in the laser soldering method.
The Impact Of The Mcu Life Extension Solvent On Dwpf Glass Formulation Efforts

International Nuclear Information System (INIS)

Peeler, D.; Edwards, T.

2011-01-01

As a part of the Actinide Removal Process (ARP)/Modular Caustic Side Solvent Extraction Unit (MCU) Life Extension Project, a next generation solvent (NG-CSSX), a new strip acid, and modified monosodium titanate (mMST) will be deployed. The strip acid will be changed from dilute nitric acid to dilute boric acid (0.01 M). Because of these changes, experimental testing with the next generation solvent and mMST is required to determine the impact of these changes in 512-S operations as well as Chemical Process Cell (CPC), Defense Waste Processing Facility (DWPF) glass formulation activities, and melter operations at DWPF. To support programmatic objectives, the downstream impacts of the boric acid strip effluent (SE) to the glass formulation activities and melter operations are considered in this study. More specifically, the impacts of boric acid additions to the projected SB7b operating windows, potential impacts to frit production temperatures, and the potential impact of boron volatility are evaluated. Although various boric acid molarities have been reported and discussed, the baseline flowsheet used to support this assessment was 0.01M boric acid. The results of the paper study assessment indicate that Frit 418 and Frit 418-7D are robust to the implementation of the 0.01M boric acid SE into the SB7b flowsheet (sludge-only or ARP-added). More specifically, the projected operating windows for the nominal SB7b projections remain essentially constant (i.e., 25-43 or 25-44% waste loading (WL)) regardless of the flowsheet options (sludge-only, ARP added, and/or the presence of the new SE). These results indicate that even if SE is not transferred to the Sludge Receipt and Adjustment Tank (SRAT), there would be no need to add boric acid (from a trim tank) to compositionally compensate for the absence of the boric acid SE in either a sludge-only or ARP-added SB7b flowsheet. With respect to boron volatility, the Measurement Acceptability Region (MAR) assessments also
Organic monolith frits encased in polyether ether ketone tubing with improved durability for liquid chromatography.

Science.gov (United States)

Park, Sin Young; Cheong, Won Jo

2015-09-01

This study introduces a preparation method for polymer-encased monolith frits with improved durability for liquid chromatography columns. The inner surface of the polyether ether ketone tubing is pretreated with sulfuric acid in the presence of catalysts (vanadium oxide and sodium sulfate). The tubing was rinsed with water and acetone, flushed with nitrogen, and treated with glycidyl methacrylate. After washing, the monolith reaction mixture composed of lauryl methacrylate, ethylene glycol dimethacrylate, initiator, and porogenic solvent was filled in the tubing and subjected to in situ polymerization. The tubing was cut into thin slices and used as frits for microcolumns. To check their durability, the frit slices were placed in a vial and a heavy impact was applied on the vial by a vortex mixer for various periods. The frits made in the presence of catalysts were found to be more durable than those made without catalysts. Furthermore, when the monolith-incorporated tubing was used as a chromatography column, the column prepared in the presence of catalysts resulted in a better separation efficiency. The separation performance of the columns installed with the polyether ether ketone encased monolith frits was comparable to that of the columns installed with the commercial stainless-steel screen frits. © 2015 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.
Leach testing of SYNROC and glass samples at 85 and 200/degree/C

International Nuclear Information System (INIS)

Oversby, V.M.; Ringwood, A.E.

1981-01-01

Leach tests were conducted on 0.5 g disc samples of SYNROC and two glass types using distilled water at 85 and 200/degree/C. No leaching was detected for SYNROC at either temperature. Thus, the upper limit on leach rate for SYNROC is <0.005 g/m/sup 2/d. Waste glass PNL 76-68 had leach rates of 1.4 g/m/sup 2/ d at 85/degree/C and 8.9 g/m/sup 2/ d at 200/degree/C, while 73-1 glass frit had a leach rate of 41 g/m/sup 2/ d at 200/degree/C. The leach tests were repeated in the presence of rock powders. Again, no leaching was measurable for SYNROC. PNL 76-68 glass had leach rates between 4 and 23 g/m/sup 2/ d at 200/degree/C and 73-1 frit leached at rates between 29 and 176 g/m/sup 2/ d at 200/degree/C. Tests were also conducted on crushed glass samples (PNL 76-68, 100-200 /mu/m size fraction). Bulk leach rates were calculated based on measurement of Ca, Cs, and U in the leach solutions. The results of the leach tests show that SYNROC is several orders of magnitude more resistant to leaching than glass
Immobilization of simulated high-level radioactive waste in borosilicate glass: Pilot scale demonstrations

International Nuclear Information System (INIS)

Ritter, J.A.; Hutson, N.D.; Zamecnik, J.R.; Carter, J.T.

1991-01-01

The Integrated DWPF Melter System (IDMS), operated by the Savannah River Laboratory, is a pilot scale facility used in support of the start-up and operation of the Department of Energy's Defense Waste Processing Facility. The IDMS has successfully demonstrated, on an engineering scale (one-fifth), that simulated high level radioactive waste (HLW) sludge can be chemically treated with formic acid to adjust both its chemical and physical properties, and then blended with simulated precipitate hydrolysis aqueous (PHA) product and borosilicate glass frit to produce a melter feed which can be processed into a durable glass product. The simulated sludge, PHA and frit were blended, based on a product composition program, to optimize the loading of the waste glass as well as to minimize those components which can cause melter processing and/or glass durability problems. During all the IDMS demonstrations completed thus far, the melter feed and the resulting glass that has been produced met all the required specifications, which is very encouraging to future DWPF operations. The IDMS operations also demonstrated that the volatile components of the melter feed (e.g., mercury, nitrogen and carbon, and, to a lesser extent, chlorine, fluorine and sulfur) did not adversely affect the melter performance or the glass product
Comparison of the corrosion behaviors of the glass-bonded sodalite ceramic waste form and reference HLW glasses

International Nuclear Information System (INIS)

Ebert, W. L.; Lewis, M. A.

1999-01-01

A glass-bonded sodalite ceramic waste form is being developed for the long-term immobilization of salt wastes that are generated during spent nuclear fuel conditioning activities. A durable waste form is prepared by hot isostatic pressing (HIP) a mixture of salt-loaded zeolite powders and glass frit. A mechanistic description of the corrosion processes is being developed to support qualification of the CWF for disposal. The initial set of characterization tests included two standard tests that have been used extensively to study the corrosion behavior of high level waste (HLW) glasses: the Material Characterization Center-1 (MCC-1) Test and the Product Consistency Test (PCT). Direct comparison of the results of tests with the reference CWF and HLW glasses indicate that the corrosion behaviors of the CWF and HLW glasses are very similar
A novel method for direct solder bump pull testing using lead-free solders

Science.gov (United States)

Turner, Gregory Alan

This thesis focuses on the design, fabrication, and evaluation of a new method for testing the adhesion strength of lead-free solders, named the Isotraction Bump Pull method (IBP). In order to develop a direct solder joint-strength testing method that did not require customization for different solder types, bump sizes, specific equipment, or trial-and-error, a combination of two widely used and accepted standards was created. First, solder bumps were made from three types of lead free solder were generated on untreated copper PCB substrates using an in-house fabricated solder bump-on-demand generator, Following this, the newly developed method made use of a polymer epoxy to encapsulate the solder bumps that could then be tested under tension using a high precision universal vertical load machine. The tests produced repeatable and predictable results for each of the three alloys tested that were in agreement with the relative behavior of the same alloys using other testing methods in the literature. The median peak stress at failure for the three solders tested were 2020.52 psi, 940.57 psi, and 2781.0 psi, and were within one standard deviation of the of all data collected for each solder. The assumptions in this work that brittle fracture occurred through the Intermetallic Compound layer (IMC) were validated with the use of Energy-Dispersive X-Ray Spectrometry and high magnification of the fractured surface of both newly exposed sides of the test specimens. Following this, an examination of the process to apply the results from the tensile tests into standard material science equations for the fracture of the systems was performed..
Lead free solder mechanics and reliability

CERN Document Server

Pang, John Hock Lye

2012-01-01

Lead-free solders are used extensively as interconnection materials in electronic assemblies and play a critical role in the global semiconductor packaging and electronics manufacturing industry. Electronic products such as smart phones, notebooks and high performance computers rely on lead-free solder joints to connect IC chip components to printed circuit boards. Lead Free Solder: Mechanics and Reliability provides in-depth design knowledge on lead-free solder elastic-plastic-creep and strain-rate dependent deformation behavior and its application in failure assessment of solder joint reliability. It includes coverage of advanced mechanics of materials theory and experiments, mechanical properties of solder and solder joint specimens, constitutive models for solder deformation behavior; numerical modeling and simulation of solder joint failure subject to thermal cycling, mechanical bending fatigue, vibration fatigue and board-level drop impact tests. This book also: Discusses the mechanical prope...
Production of muscovite-feldspathic glass composite: scanning electron microscopy and X-ray diffraction analysis

International Nuclear Information System (INIS)

Costa, F.P.F.; Ogasawara, T.; Santos, S.F.

2009-01-01

The objective of this work was to find the sintering conditions for the feldspathic glass + muscovite mixture to produce a dense composite block for manufacturing dental prosthesis by using CAD-CAM. Each 20g of the glass-frit had : 15.55g of Armil-feldspar; 0.53g of Al 2 O 3 ; 1.56g of Na 2 CO 3 ; 0.5g of borax; 1.74g of K 2 CO 3 ; 0.13g of CeO 2 . Frit's powder finer than 350 Tyler mesh was mixed with 0 wt%, 10 wt%, 20 wt% and 100 wt% of muscovite pressed cylinders (5600 pounds force) 16mm in diameter and sintered under vacuum Vacumat (VITA) furnace at 850 deg C, 900 deg C, 950 deg C, 1000 deg C, 1050 deg C, 1100 deg C and 1150 deg C. X-ray diffraction analysis and scanning electron microscopy were carried out. The necessary temperature for high densification depended on the composition of the mixture: 850 deg C (for pure frit); 1050 deg C (for 10 wt% mica) and 1150 deg C (for 20 wt% mica); pure mica degraded during sintering. (author)
Demonstration of the Defense Waste Processing Facility vitrification process for Tank 42 radioactive sludge -- Glass preparation and characterization

International Nuclear Information System (INIS)

Bibler, N.E.; Fellinger, T.L.; Marshall, K.M.; Crawford, C.L.; Cozzi, A.D.; Edwards, T.B.

1999-01-01

The Defense Waste Processing Facility (DWPF) at the Savannah River Site (SRS) is currently processing and immobilizing the radioactive high level waste sludge at SRS into a durable borosilicate glass for final geological disposal. The DWPF has recently finished processing the first radioactive sludge batch, and is ready for the second batch of radioactive sludge. The second batch is primarily sludge from Tank 42. Before processing this batch in the DWPF, the DWPF process flowsheet has to be demonstrated with a sample of Tank 42 sludge to ensure that an acceptable melter feed and glass can be made. This demonstration was recently completed in the Shielded Cells Facility at SRS. An earlier paper in these proceedings described the sludge composition and processes necessary for producing an acceptable melter fee. This paper describes the preparation and characterization of the glass from that demonstration. Results substantiate that Tank 42 sludge after mixing with the proper amount of glass forming frit (Frit 200) can be processed to make an acceptable glass

DETERMINATION OF HLW GLASS MELT RATE USING X-RAY COMPUTED TOMOGRAPHY

Energy Technology Data Exchange (ETDEWEB)

Choi, A.; Miller, D.; Immel, D.

2011-10-06

The purpose of the high-level waste (HLW) glass melt rate study is two-fold: (1) to gain a better understanding of the impact of feed chemistry on melt rate through bench-scale testing, and (2) to develop a predictive tool for melt rate in support of the on-going frit development efforts for the Defense Waste Processing Facility (DWPF). In particular, the focus is on predicting relative melt rates, not the absolute melt rates, of various HLW glass formulations solely based on feed chemistry, i.e., the chemistry of both waste and glass-forming frit for DWPF. Critical to the successful melt rate modeling is the accurate determination of the melting rates of various HLW glass formulations. The baseline procedure being used at the Savannah River National Laboratory (SRNL) is to; (1) heat a 4 inch-diameter stainless steel beaker containing a mixture of dried sludge and frit in a furnace for a preset period of time, (2) section the cooled beaker along its diameter, and (3) measure the average glass height across the sectioned face using a ruler. As illustrated in Figure 1-1, the glass height is measured for each of the 16 horizontal segments up to the red lines where relatively large-sized bubbles begin to appear. The linear melt rate (LMR) is determined as the average of all 16 glass height readings divided by the time during which the sample was kept in the furnace. This 'visual' method has proved useful in identifying melting accelerants such as alkalis and sulfate and further ranking the relative melt rates of candidate frits for a given sludge batch. However, one of the inherent technical difficulties of this method is to determine the glass height in the presence of numerous gas bubbles of varying sizes, which is prevalent especially for the higher-waste-loading glasses. That is, how the red lines are drawn in Figure 1-1 can be subjective and, therefore, may influence the resulting melt rates significantly. For example, if the red lines are drawn too low
Glass Frit Dissolution Influenced by Material Composition and the Water Content in Iodide/Triiodide Electrolyte of Dye-Sensitized Solar Cells

Directory of Open Access Journals (Sweden)

Katrine Flarup Jensen

2013-01-01

Full Text Available To ensure long-term stable dye-sensitized solar cells (DSCs and modules, a hermetic sealing is required. This research investigates the chemical stability of I-/I3- redox electrolyte and four different glass frits (GFs. Sintered GF layers were openly exposed to nonaqueous redox electrolyte and redox electrolyte with 1, 5, and 10 wt% H2O in thin, encapsulated cells. The change in I3− absorbance was assigned to a reaction between the GF and I-/I3- electrolyte and was used to evaluate the chemical stability of the different GFs. The I3− absorbance change was monitored over 100 days. Two out of the four GFs were unstable when H2O was added to the redox electrolyte. The H2O caused metal ion leaching which was determined from EDX analysis of the inorganic remains of electrolyte samples. A GF based on Bi2O3–SiO2–B2O3 with low bond strength leached bismuth into electrolyte and formed the BiI3- complex. A ZnO–SiO2–Al2O3-based GF also became unstable when H2O was added to the redox electrolyte. Leaching of zinc ions due to exchange with H+ resulted in the formation of a zinc-iodine compound which caused I3− depletion. By applying the test design to different types of GFs, the material suitability in the DSC working environment was investigated.
The effect of pre-treatment parameters on the quality of glass-ceramic wasteforms for plutonium immobilisation, consolidated by hot isostatic pressing

Energy Technology Data Exchange (ETDEWEB)

Thornber, Stephanie M.; Heath, Paul G. [Immobilisation Science Laboratory, Department of Materials Science & Engineering, The University of Sheffield, Sir Robert Hadfield Building, Mappin Street, Sheffield S1 3JD (United Kingdom); Da Costa, Gabriel P. [Immobilisation Science Laboratory, Department of Materials Science & Engineering, The University of Sheffield, Sir Robert Hadfield Building, Mappin Street, Sheffield S1 3JD (United Kingdom); Department of Chemical Engineering & Petroleum Engineering, Universidade Federal Fluminense, Rua Passo da Patria 156, CEP 24210-240, Niteroi, RJ (Brazil); Stennett, Martin C. [Immobilisation Science Laboratory, Department of Materials Science & Engineering, The University of Sheffield, Sir Robert Hadfield Building, Mappin Street, Sheffield S1 3JD (United Kingdom); Hyatt, Neil C., E-mail: n.c.hyatt@sheffield.ac.uk [Immobilisation Science Laboratory, Department of Materials Science & Engineering, The University of Sheffield, Sir Robert Hadfield Building, Mappin Street, Sheffield S1 3JD (United Kingdom)

2017-03-15

Glass-ceramics with high glass fractions (70 wt%) were fabricated in stainless steel canisters by hot isostatic pressing (HIP), at laboratory scale. High (600 °C) and low (300 °C) temperature pre-treatments were investigated to reduce the canister evacuation time and to understand the effect on the phase assemblage and microstructure of the hot isostatically pressed product. Characterisation of the HIPed materials was performed using scanning electron microscopy (SEM), coupled with energy dispersive X-ray analysis (EDX) and powder X-ray diffraction (XRD). This analysis showed the microstructure and phase assemblage was independent of the variation in pre-treatment parameters. It was demonstrated that a high temperature pre-treatment of batch reagents, prior to the HIP cycle, is beneficial when using oxide precursors, in order to remove volatiles and achieve high quality dense materials. Sample throughput can be increased significantly by utilising a high temperature ex-situ calcination prior to the HIP cycle. Investigation of glass-ceramic wasteform processing utilising a glass frit precursor, produced a phase assemblage and microstructure comparable to that obtained using oxide precursors. The use of a glass frit precursor should allow optimised throughput of waste packages in a production facility, avoiding the need for a calcination pre-treatment required to remove volatiles from oxide precursors. - Highlights: • Optimisation of pre-treatment parameters for HIP glass-ceramics was investigated. • Entrained porosity was minimised by ex-situ bake-out of oxide precursors at 600 °C. • Phase assemblage and microstructure proved independent of bake-out parameters. • Use of glass-frit precursor further improved process s throughput and simplification.
The effect of pre-treatment parameters on the quality of glass-ceramic wasteforms for plutonium immobilisation, consolidated by hot isostatic pressing

International Nuclear Information System (INIS)

Thornber, Stephanie M.; Heath, Paul G.; Da Costa, Gabriel P.; Stennett, Martin C.; Hyatt, Neil C.

2017-01-01

Glass-ceramics with high glass fractions (70 wt%) were fabricated in stainless steel canisters by hot isostatic pressing (HIP), at laboratory scale. High (600 °C) and low (300 °C) temperature pre-treatments were investigated to reduce the canister evacuation time and to understand the effect on the phase assemblage and microstructure of the hot isostatically pressed product. Characterisation of the HIPed materials was performed using scanning electron microscopy (SEM), coupled with energy dispersive X-ray analysis (EDX) and powder X-ray diffraction (XRD). This analysis showed the microstructure and phase assemblage was independent of the variation in pre-treatment parameters. It was demonstrated that a high temperature pre-treatment of batch reagents, prior to the HIP cycle, is beneficial when using oxide precursors, in order to remove volatiles and achieve high quality dense materials. Sample throughput can be increased significantly by utilising a high temperature ex-situ calcination prior to the HIP cycle. Investigation of glass-ceramic wasteform processing utilising a glass frit precursor, produced a phase assemblage and microstructure comparable to that obtained using oxide precursors. The use of a glass frit precursor should allow optimised throughput of waste packages in a production facility, avoiding the need for a calcination pre-treatment required to remove volatiles from oxide precursors. - Highlights: • Optimisation of pre-treatment parameters for HIP glass-ceramics was investigated. • Entrained porosity was minimised by ex-situ bake-out of oxide precursors at 600 °C. • Phase assemblage and microstructure proved independent of bake-out parameters. • Use of glass-frit precursor further improved process s throughput and simplification.
Frit Development Efforts for Sludge Batch 4 (SB4): Operating Window Assessments of Scenarios Leading Up to the Selected Preparation Plan for SB4

International Nuclear Information System (INIS)

Peeler, D

2006-01-01

The objective of this report is to document technical information that has been provided to Defense Waste Processing Facility (DWPF) and Closure Business Unit (CBU) personnel as part of the frit development support for Sludge Batch 4 (SB4). The information presented in this report includes projected operating windows (expressed in terms of waste loading) for various sludge blending and/or washing options coupled with candidate frits of interest. Although the Nominal Stage assessment serves as the primary tool for these evaluations, select systems were also evaluated using a Variation Stage assessment in which compositional variations were introduced. In addition, assessments of the impacts of nepheline formation potential and the SO 4 - solubility limit on the projected operating windows are also provided. Although this information was used as part of the technical basis leading to CBU's development of the preferred SB4 preparation plan, none of the options presented in this report was selected as the preferred plan. Therefore, the information is presented without significant interpretation of the resulting operating windows, but the projected windows are provided so additional insight can be explored if desired. Detailed assessments of the projected operating windows (using both Nominal and Variation Stage assessments) of the preferred sludge preparation plan with candidate frits are to be documented elsewhere. The information provided in this report is focused solely on model-based projections of the operating windows for various SB4 blending strategies of interest. Although nepheline formation potential is monitored via model predictions as a part of this assessment, experimental work investigating the impact of nepheline on glass quality is also being addressed in a parallel study. The results of this paper study and the experimental assessments of melt rate, SO 4 solubility, and/or nepheline formation potential are all critical components of the inputs into
Spectral studies on CuO in sodium–calcium borophosphate glasses

Indian Academy of Sciences (India)

linear optical devices [10] and as low-melting glass solders or glass seals [11] derived .... For S1 to S4 samples, the vitreous phase coexists with a crystalline phase and the pattern shows large maxima overlapped with the peaks characteristics ...
Solder joint technology materials, properties, and reliability

CERN Document Server

Tu, King-Ning

2007-01-01

Solder joints are ubiquitous in electronic consumer products. The European Union has a directive to ban the use of Pb-based solders in these products on July 1st, 2006. There is an urgent need for an increase in the research and development of Pb-free solders in electronic manufacturing. For example, spontaneous Sn whisker growth and electromigration induced failure in solder joints are serious issues. These reliability issues are quite complicated due to the combined effect of electrical, mechanical, chemical, and thermal forces on solder joints. To improve solder joint reliability, the science of solder joint behavior under various driving forces must be understood. In this book, the advanced materials reliability issues related to copper-tin reaction and electromigration in solder joints are emphasized and methods to prevent these reliability problems are discussed.
Spontaneous soldering

International Nuclear Information System (INIS)

Percacci, R.

1984-01-01

It is proposed that the soldering form of general relativity be treated as a dynamical variable. This gives rise to the possibility of treating the linear connection on (n-dimensional) spacetime and an internal O(k)-Yang-Mills field as different components of the same O(N) gauge field (N= n+k). The distinction between gravitational and Yang-Mills interactions is due to a kind of Higgs mechanism driven by the vacuum expectation value of the soldering form. (orig.)
Soldering of Nanotubes onto Microelectrodes

DEFF Research Database (Denmark)

Madsen, Dorte Nørgaard; Mølhave, Kristian; Mateiu, Ramona Valentina

2003-01-01

Suspended bridges of individual multiwalled carbon nanotubes were fabricated inside a scanning electron microscope by soldering the nanotube onto microelectrodes with highly conducting gold-carbon material. By the decomposition of organometallic vapor with the electron beam, metal-containing sold...... bonds were consistently found to be mechanically stronger than the carbon nanotubes.......Suspended bridges of individual multiwalled carbon nanotubes were fabricated inside a scanning electron microscope by soldering the nanotube onto microelectrodes with highly conducting gold-carbon material. By the decomposition of organometallic vapor with the electron beam, metal-containing solder...... bonds were formed at the intersection of the nanotube and the electrodes. Current-voltage curves indicated metallic conduction of the nanotubes, with resistances in the range of 9-29 kOmega. Bridges made entirely of the soldering material exhibited resistances on the order of 100 Omega, and the solder...
Foaming of CRT panel glass powder with Na2CO3

DEFF Research Database (Denmark)

Petersen, Rasmus Rosenlund; König, Jakob; Smedskjær, Morten Mattrup

melt, while Na2O becomes incorporated into the glass structure. We have quantified the melt expansion through density measurements and the Na2O incorporation is indicated by the decrease of the glass transition temperature (Tg) of the final foam glass. The glass foaming quality depends on the foaming......Recycling of cathode ray tube (CRT) glass remains a challenging task. The CRT glass consists of four glass types fused together: Funnel-, neck-, frit- and panel glass. The three former glasses contain toxic lead oxide, and therefore have a low recycling potential. The latter on the other hand...... is lead-free, but since barium and strontium oxide are present, panel glass is incompatible with most common recycling methods. However, foam glass production is a promising approach for the recycling of panel glass waste, since the process parameters can be changed according to the glass waste...
Properties of glass-bonded zeolite monoliths

International Nuclear Information System (INIS)

Lewis, M.A.; Fischer, D.F.; Murphy, C.D.

1994-01-01

It has been shown that mineral waste forms can be used to immobilize waste salt generated during the pyrochemical processing of spent fuel from the Integral Fast Reactor (IFR). Solid, leach resistant monoliths were formed by hot-pressing mixtures of salt-occluded zeolite A powders and glass frit at 990 K and 28 MPa. Additional samples have now been fabricated and tested. Normalized release rates for all elements, including iodide and chloride, were less than 1 g/m 2 d in 28-day tests in deionized water and in brine at 363 K (90 degrees C). Preliminary results indicate that these rates fall with time with both leachants and that the zeolite phase in the glass-bonded zeolite does not function as an ion exchanger. Some material properties were measured. The Poisson ratio and Young's modulus were slightly smaller in glass-bonded zeolite than in borosilicate glass. Density depended on zeolite fraction. The glass-bonded zeolite represents a promising mineral waste form for IFR salt
Reliability Study of Solder Paste Alloy for the Improvement of Solder Joint at Surface Mount Fine-Pitch Components

Directory of Open Access Journals (Sweden)

Mohd Nizam Ab. Rahman

2014-12-01

Full Text Available The significant increase in metal costs has forced the electronics industry to provide new materials and methods to reduce costs, while maintaining customers’ high-quality expectations. This paper considers the problem of most electronic industries in reducing costly materials, by introducing a solder paste with alloy composition tin 98.3%, silver 0.3%, and copper 0.7%, used for the construction of the surface mount fine-pitch component on a Printing Wiring Board (PWB. The reliability of the solder joint between electronic components and PWB is evaluated through the dynamic characteristic test, thermal shock test, and Taguchi method after the printing process. After experimenting with the dynamic characteristic test and thermal shock test with 20 boards, the solder paste was still able to provide a high-quality solder joint. In particular, the Taguchi method is used to determine the optimal control parameters and noise factors of the Solder Printer (SP machine, that affects solder volume and solder height. The control parameters include table separation distance, squeegee speed, squeegee pressure, and table speed of the SP machine. The result shows that the most significant parameter for the solder volume is squeegee pressure (2.0 mm, and the solder height is the table speed of the SP machine (2.5 mm/s.
Effect of soldering techniques and gap distance on tensile strength of soldered Ni-Cr alloy joint.

Science.gov (United States)

Lee, Sang-Yeob; Lee, Jong-Hyuk

2010-12-01

The present study was intended to evaluate the effect of soldering techniques with infrared ray and gas torch under different gap distances (0.3 mm and 0.5 mm) on the tensile strength and surface porosity formation in Ni-Cr base metal alloy. Thirty five dumbbell shaped Ni-Cr alloy specimens were prepared and assigned to 5 groups according to the soldering method and the gap distance. For the soldering methods, gas torch (G group) and infrared ray (IR group) were compared and each group was subdivided by corresponding gap distance (0.3 mm: G3 and IR3, 0.5 mm: G5, IR5). Specimens of the experimental groups were sectioned in the middle with a diamond disk and embedded in solder blocks according to the predetermined distance. As a control group, 7 specimens were prepared without sectioning or soldering. After the soldering procedure, a tensile strength test was performed using universal testing machine at a crosshead speed 1 mm/min. The proportions of porosity on the fractured surface were calculated on the images acquired through the scanning electronic microscope. Every specimen of G3, G5, IR3 and IR5 was fractured on the solder joint area. However, there was no significant difference between the test groups (P > .05). There was a negative correlation between porosity formation and tensile strength in all the specimens in the test groups (P tensile strength of joints and porosity formations between the gas-oxygen torch soldering and infrared ray soldering technique or between the gap distance of 0.3 mm and 0.5 mm.
Floor tile glass-ceramic glaze for improvement of the resistance to surface abrasion

Science.gov (United States)

Gajek, M.; Lis, J.; Partyka, J.; Wójczyk, M.

2011-10-01

The results of research aimed at the study on frits and glass-ceramic glazes for floor tiles, based on compositions located in the primary field of cordierite crystallization within the system MgO-Al2O3-SiO2, have been presented. The results comprise investigations on the frits crystallization abilities, stability of the crystallizing phase under conditions of single-stage a fast firing cycle (time below 60 minutes) depending on their chemical composition and the influence of the nucleation agents. The influence of the nucleating agents namely TiO2, ZrO2, V2O5 on phase composition of obtained crystalline glazes, mechanical parameters and microstructure, has been examined. The strength tests proved increased mechanical resistance of crystalline glazes. Obtained glazes are characterized by high microhardness in range 6~8 GPa, as well as the increased wear resistance measured by the loss of weight below 100 mg / 55 cm2 (PN-EN ISO 10545-7). Significant increase of these parameters as compared with non-crystalline glazes, where micro-hardness values range between 5~6 GPa and the wear resistance values range from 120 to 200 mg, has been proved. Starting glasses (frits) and glazes of the ternary system MgO-SiO2-Al2O3, were examined with use of DTA, XRD and SEM methods.
Floor tile glass-ceramic glaze for improvement of the resistance to surface abrasion

International Nuclear Information System (INIS)

Gajek, M; Lis, J; Partyka, J; Wojczyk, M

2011-01-01

The results of research aimed at the study on frits and glass-ceramic glazes for floor tiles, based on compositions located in the primary field of cordierite crystallization within the system MgO-Al 2 O 3 -SiO 2 , have been presented. The results comprise investigations on the frits crystallization abilities, stability of the crystallizing phase under conditions of single-stage a fast firing cycle (time below 60 minutes) depending on their chemical composition and the influence of the nucleation agents. The influence of the nucleating agents namely TiO 2 , ZrO 2 , V 2 O 5 on phase composition of obtained crystalline glazes, mechanical parameters and microstructure, has been examined. The strength tests proved increased mechanical resistance of crystalline glazes. Obtained glazes are characterized by high microhardness in range 6∼8 GPa, as well as the increased wear resistance measured by the loss of weight below 100 mg / 55 cm 2 (PN-EN ISO 10545-7). Significant increase of these parameters as compared with non-crystalline glazes, where micro-hardness values range between 5∼6 GPa and the wear resistance values range from 120 to 200 mg, has been proved. Starting glasses (frits) and glazes of the ternary system MgO-SiO 2 -Al 2 O 3 , were examined with use of DTA, XRD and SEM methods.
Spectroscopic investigation of oxidized solder surfaces

International Nuclear Information System (INIS)

Song, Jenn-Ming; Chang-Chien, Yu-Chien; Huang, Bo-Chang; Chen, Wei-Ting; Shie, Chi-Rung; Hsu, Chuang-Yao

2011-01-01

Highlights: → UV-visible spectroscopy is successfully used to evaluate the degree of discoloring of solders. → The surface oxides of solders can also be identified by UV-visible absorption spectra. → The discoloration of solder surface can be correlated with optical characterization of oxides. → A strategy against discoloring by alloying was also suggested. - Abstract: For further understanding of the discoloration of solder surfaces due to oxidation during the assembly and operation of electronic devices, UV-vis and X-ray photoelectron spectroscopic analyses were applied to evaluate the degree of discoloring and identify the surface oxides. The decrease in reflectance of the oxidized solder surface is related to SnO whose absorption band is located within the visible region. A trace of P can effectively depress the discoloration of solders under both solid and semi-solid states through the suppression of SnO.
Solderability study of RABiTS-based YBCO coated conductors

International Nuclear Information System (INIS)

Zhang Yifei; Duckworth, Robert C.; Ha, Tam T.; Gouge, Michael J.

2011-01-01

Study examines the implication of solder and flux selection in YBCO splice joints. Focus is on commercially available RABiTS-based YBCO coated conductors. Solderability varied with solder and flux for three different stabilizations tested. Resistivity of stabilizer was dominant factor in splice joint resistance. Solder materials affected splice joint resistance when solderability was poor. The solderability of commercially available YBa 2 Cu 3 O 7-x (YBCO) coated conductors that were made from Rolling Assisted Biaxially Textured Substrates (RABiTS)-based templates was studied. The coated conductors, also known as second-generation (2G) high temperature superconductor (HTS) wires (in the geometry of flat tapes about 4 mm wide), were laminated with copper, brass, or stainless steel strips as stabilizers. To understand the factors that influence their solderability, surface profilometry and scanning electron microscopy were used to characterize the wire surfaces. The solderability of three solders, 52In48Sn, 67Bi33In, and 100In (wt.%), was evaluated using a standard test (IPC/ECA J-STD-002) and with two different commercial fluxes. It was found that the solderability varied with the solder and flux but the three different wires showed similar solderability for a fixed combination of solder and flux. Solder joints of the 2G wires were fabricated using the tools and the procedures recommended by the HTS wire manufacturer. The solder joints were made in a lap-joint geometry and with the superconducting sides of the two wires face-to-face. The electrical resistances of the solder joints were measured at 77 K, and the results were analyzed to qualify the soldering materials and evaluate the soldering process. It was concluded that although the selection of soldering materials affected the resistance of a solder joint, the resistivity of the stabilizer was the dominant factor.
Optimal parameters for laser tissue soldering

Science.gov (United States)

McNally-Heintzelman, Karen M.; Sorg, Brian S.; Chan, Eric K.; Welch, Ashley J.; Dawes, Judith M.; Owen, Earl R.

1998-07-01

Variations in laser irradiance, exposure time, solder composition, chromophore type and concentration have led to inconsistencies in published results of laser-solder repair of tissue. To determine optimal parameters for laser tissue soldering, an in vitro study was performed using an 808-nm diode laser in conjunction with an indocyanine green (ICG)- doped albumin protein solder to weld bovine aorta specimens. Liquid and solid protein solders prepared from 25% and 60% bovine serum albumin (BSA), respectively, were compared. The effects of laser irradiance and exposure time on tensile strength of the weld and temperature rise as well as the effect of hydration on bond stability were investigated. Optimum irradiance and exposure times were identified for each solder type. Increasing the BSA concentration from 25% to 60% greatly increased the tensile strength of the weld. A reduction in dye concentration from 2.5 mg/ml to 0.25 mg/ml was also found to result in an increase in tensile strength. The strongest welds were produced with an irradiance of 6.4 W/cm2 for 50 s using a solid protein solder composed of 60% BSA and 0.25 mg/ml ICG. Steady-state solder surface temperatures were observed to reach 85 plus or minus 5 degrees Celsius with a temperature gradient across the solid protein solder strips of between 15 and 20 degrees Celsius. Finally, tensile strength was observed to decrease significantly (20 to 25%) after the first hour of hydration in phosphate-buffered saline. No appreciable change was observed in the strength of the tissue bonds with further hydration.
Disposition of actinides released from high-level waste glass

International Nuclear Information System (INIS)

Ebert, W.L.; Bates, J.K.; Buck, E.C.; Gong, M.; Wolf, S.F.

1994-01-01

A series of static leach tests was conducted using glasses developed for vitrifying tank wastes at the Savannah River Site to monitor the disposition of actinide elements upon corrosion of the glasses. In these tests, glasses produced from SRL 131 and SRL 202 frits were corroded at 90 degrees C in a tuff groundwater. Tests were conducted using crushed glass at different glass surface area-to-solution volume (S/V) ratios to assess the effect of the S/V on the solution chemistry, the corrosion of the glass, and the disposition of actinide elements. Observations regarding the effects of the S/V on the solution chemistry and the corrosion of the glass matrix have been reported previously. This paper highlights the solution analyses performed to assess how the S/V used in a static leach test affects the disposition of actinide elements between fractions that are suspended or dissolved in the solution, and retained by the altered glass or other materials
Handbook of machine soldering SMT and TH

CERN Document Server

Woodgate, Ralph W

1996-01-01

A shop-floor guide to the machine soldering of electronics Sound electrical connections are the operational backbone of every piece of electronic equipment-and the key to success in electronics manufacturing. The Handbook of Machine Soldering is dedicated to excellence in the machine soldering of electrical connections. Self-contained, comprehensive, and down-to-earth, it cuts through jargon, peels away outdated notions, and presents all the information needed to select, install, and operate machine soldering equipment. This fully updated and revised volume covers all of the new technologies and processes that have emerged in recent years, most notably the use of surface mount technology (SMT). Supplemented with 200 illustrations, this thoroughly accessible text Describes reflow and wave soldering in detail, including reflow soldering of SMT boards and the use of nitrogen blankets * Explains the setup, operation, and maintenance of a variety of soldering machines * Discusses theory, selection, and control met...

Photothermal effects of laser tissue soldering

International Nuclear Information System (INIS)

McNally, K.M.; Sorg, B.S.; Welch, A.J.; Dawes, J.M.; Owen, E.R.

1999-01-01

Low-strength anastomoses and thermal damage of tissue are major concerns in laser tissue welding techniques where laser energy is used to induce thermal changes in the molecular structure of the tissues being joined, hence allowing them to bond together. Laser tissue soldering, on the other hand, is a bonding technique in which a protein solder is applied to the tissue surfaces to be joined, and laser energy is used to bond the solder to the tissue surfaces. The addition of protein solders to augment tissue repair procedures significantly reduces the problems of low strength and thermal damage associated with laser tissue welding techniques. Investigations were conducted to determine optimal solder and laser parameters for tissue repair in terms of tensile strength, temperature rise and damage and the microscopic nature of the bonds formed. An in vitro study was performed using an 808 nm diode laser in conjunction with indocyanine green (ICG)-doped albumin protein solders to repair bovine aorta specimens. Liquid and solid protein solders prepared from 25% and 60% bovine serum albumin (BSA), respectively, were compared. The efficacy of temperature feedback control in enhancing the soldering process was also investigated. Increasing the BSA concentration from 25% to 60% greatly increased the tensile strength of the repairs. A reduction in dye concentration from 2.5mgml -1 to 0.25mgml -1 was also found to result in an increase in tensile strength. Increasing the laser irradiance and thus surface temperature resulted in an increased severity of histological injury. Thermal denaturation of tissue collagen and necrosis of the intimal layer smooth muscle cells increased laterally and in depth with higher temperatures. The strongest repairs were produced with an irradiance of 6.4Wcm -2 using a solid protein solder composed of 60% BSA and 0.25mgml -1 ICG. Using this combination of laser and solder parameters, surface temperatures were observed to reach 85±5 deg. C with a
Effect of solder bump size on interfacial reactions during soldering between Pb-free solder and Cu and Ni/ Pd/ Au surface finishes

International Nuclear Information System (INIS)

NorAkmal, F.; Ourdjini, A.; Azmah Hanim, M.A.; Siti Aisha, I.; Chin, Y.T.

2007-01-01

Flip chip technology provides the ultimate in high I/ O-density and count with superior electrical performance for interconnecting electronic components. Therefore, the study of the intermetallic compounds was conducted to investigate the effect of solder bumps sizes on several surface finishes which are copper and Electroless Nickel/ Electroless Palladium/ Immersion Gold (ENEPIG) which is widely used in electronics packaging as surface finish for flip-chip application nowadays. In this research, field emission scanning electron microscopy (FESEM) analysis was conducted to analyze the morphology and composition of intermetallic compounds (IMCs) formed at the interface between the solder and UBM. The IMCs between the SAC lead-free solder with Cu surface finish after reflow were mainly (Cu, Ni) 6 Sn 5 and Cu 6 Sn 5 . While the main IMCs formed between lead-free solder on ENEPIG surface finish are (Ni, Cu) 3 Sn 4 and Ni 3 Sn 4 . The results from FESEM with energy dispersive x-ray (EDX) have revealed that isothermal aging at 150 degree Celsius has caused the thickening and coarsening of IMCs as well as changing them into more spherical shape. The thickness of the intermetallic compounds in both finishes investigated was found to be higher in solders with smaller bump size. From the experimental results, it also appears that the growth rate of IMCs is higher when soldering on copper compared to ENEPIG finish. Besides that, the results also showed that the thickness of intermetallic compounds was found to be proportional to isothermal aging duration. (author)
Characterizing the Soldering Alloy Type In–Ag–Ti and the Study of Direct Soldering of SiC Ceramics and Copper

Directory of Open Access Journals (Sweden)

Roman Koleňák

2018-04-01

Full Text Available The aim of the research was to characterize the soldering alloy In–Ag–Ti type, and to study the direct soldering of SiC ceramics and copper. The In10Ag4Ti solder has a broad melting interval, which mainly depends on its silver content. The liquid point of the solder is 256.5 °C. The solder microstructure is composed of a matrix with solid solution (In, in which the phases of titanium (Ti3In4 and silver (AgIn2 are mainly segregated. The tensile strength of the solder is approximately 13 MPa. The strength of the solder increased with the addition of Ag and Ti. The solder bonds with SiC ceramics, owing to the interaction between active In metal and silicon infiltrated in the ceramics. XRD analysis has proven the interaction of titanium with ceramic material during the formation of the new minority phases of titanium silicide—SiTi and titanium carbide—C5Ti8. In and Ag also affect bond formation with the copper substrate. Two new phases were also observed in the bond interphase—(CuAg6In5 and (AgCuIn2. The average shear strength of a combined joint of SiC–Cu, fabricated with In10Ag4Ti solder, was 14.5 MPa. The In–Ag–Ti solder type studied possesses excellent solderability with several metallic and ceramic materials.
Valorization of sugarcane bagasse ash: producing glass-ceramic materials.

Science.gov (United States)

Teixeira, S R; Magalhães, R S; Arenales, A; Souza, A E; Romero, M; Rincón, J M

2014-02-15

Some aluminosilicates, for example mullite and wollastonite, are very important in the ceramic and construction industries. The most significant glass-ceramic for building applications has wollastonite as the main crystal phase. In this work we report on the use of sugarcane bagasse ash (SCBA) to produce glass-ceramics with silicates as the major crystalline phases. The glasses (frits) were prepared by mixing ash, limestone (calcium and magnesium carbonates) and potassium carbonate as the fluxing agent. X-ray fluorescence was used to determine the chemical composition of the glasses and their crystallization was assessed by using thermal analysis (DTA/DSC/TGA) and X-ray diffraction. The results showed that glass-ceramic material can be produced with wollastonite as the major phase, at a temperature lower than 900 °C. Copyright © 2014 Elsevier Ltd. All rights reserved.
Introduction to the crystallization phenomenon in nuclear glass

International Nuclear Information System (INIS)

Jacquet Francillon, N.

1997-01-01

Crystallization is a subject for concern because of its potentially detrimental effects on the technological feasibility of high-temperature melting, and on the chemical durability of the material at intermediate and low temperatures during interim storage or after disposal. The tendency of glass to crystallize depends to a large extent on the composition of the frit and/or of the waste to be solidified. It depends too of the thermal history of the glass generally, the knowledge is mainly upon determination of the time-temperature-transition (TTT) curves, crystal identification and quantification techniques, and their effects on the durability of the glass matrix. French experience is presented. Only a few authors addressed the long-term development of crystalline phases, notably at temperatures below the vitreous transition temperature Tg. Some recommendations for glass crystallization studies are made but glass crystallization after disposal is acceptable provided some conditions are met. (author)
DWPF waste glass Product Composition Control System

International Nuclear Information System (INIS)

Brown, K.G.; Postles, R.L.

1992-01-01

The Defense Waste Processing Facility (DWPF) will be used to blend aqueous radwaste (PHA) with solid radwaste (Sludge) in a waste receipt vessel (the SRAT). The resulting SRAT material is transferred to the SME an there blended with ground glass (Frit) to produce a batch of melter feed slurry. The SME material is passed to a hold tank (the MFT) which is used to continuously feed the DWPF melter. The melter. The melter produces a molten glass wasteform which is poured into stainless steel canisters for cooling and, ultimately, shipment to and storage in a geologic repository. The Product Composition Control System (PCCS) is the system intended to ensure that the melt will be processible and that the glass wasteform will be acceptable. This document provides a description of this system
SUMMARY OF FY11 SULFATE RETENTION STUDIES FOR DEFENSE WASTE PROCESSING FACILITY GLASS

Energy Technology Data Exchange (ETDEWEB)

Fox, K.; Edwards, T.

2012-05-08

necessary to have a dramatic impact on blending, washing, or waste loading strategies for DWPF) for the glasses studied here. In general, the concentrations of those species that significantly improve sulfate solubility in a borosilicate glass must be added in relatively large concentrations (e.g., 13 to 38 wt % or more of the frit) in order to have a substantial impact. For DWPF, these concentrations would constitute too large of a portion of the frit to be practical. Therefore, it is unlikely that specific additives may be introduced into the DWPF glass via the frit to significantly improve sulfate solubility. The results presented here continue to show that sulfate solubility or retention is a function of individual glass compositions, rather than a property of a broad glass composition region. It would therefore be inappropriate to set a single sulfate concentration limit for a range of DWPF glass compositions. Sulfate concentration limits should continue to be identified and implemented for each sludge batch. The current PCCS limit is 0.4 wt % SO{sub 4}{sup 2-} in glass, although frit development efforts have led to an increased limit of 0.6 wt % for recent sludge batches. Slightly higher limits (perhaps 0.7-0.8 wt %) may be possible for future sludge batches. An opportunity for allowing a higher sulfate concentration limit at DWPF may lay lie in improving the laboratory experiments used to set this limit. That is, there are several differences between the crucible-scale testing currently used to define a limit for DWPF operation and the actual conditions within the DWPF melter. In particular, no allowance is currently made for sulfur partitioning (volatility versus retention) during melter processing as the sulfate limit is set for a specific sludge batch. A better understanding of the partitioning of sulfur in a bubbled melter operating with a cold cap as well as the impacts of sulfur on the off-gas system may allow a higher sulfate concentration limit to be
Floor tile glass-ceramic glaze for improvement of the resistance to surface abrasion

Energy Technology Data Exchange (ETDEWEB)

Gajek, M; Lis, J; Partyka, J; Wojczyk, M, E-mail: mgajek@agh.edu.pl [AGH University of Science and Technology, Faculty of Materials Science and Ceramic, al. Mickiewicza 30, 30-059 Cracow (Poland)

2011-10-29

The results of research aimed at the study on frits and glass-ceramic glazes for floor tiles, based on compositions located in the primary field of cordierite crystallization within the system MgO-Al{sub 2}O{sub 3}-SiO{sub 2}, have been presented. The results comprise investigations on the frits crystallization abilities, stability of the crystallizing phase under conditions of single-stage a fast firing cycle (time below 60 minutes) depending on their chemical composition and the influence of the nucleation agents. The influence of the nucleating agents namely TiO{sub 2}, ZrO{sub 2}, V{sub 2}O{sub 5} on phase composition of obtained crystalline glazes, mechanical parameters and microstructure, has been examined. The strength tests proved increased mechanical resistance of crystalline glazes. Obtained glazes are characterized by high microhardness in range 6{approx}8 GPa, as well as the increased wear resistance measured by the loss of weight below 100 mg / 55 cm{sup 2} (PN-EN ISO 10545-7). Significant increase of these parameters as compared with non-crystalline glazes, where micro-hardness values range between 5{approx}6 GPa and the wear resistance values range from 120 to 200 mg, has been proved. Starting glasses (frits) and glazes of the ternary system MgO-SiO{sub 2}-Al{sub 2}O{sub 3}, were examined with use of DTA, XRD and SEM methods.
Interface between Sn-Sb-Cu solder and copper substrate

Energy Technology Data Exchange (ETDEWEB)

Sebo, P., E-mail: Pavel.Sebo@savba.sk [Institute of Materials and Machine Mechanics, Slovak Academy of Sciences, Racianska 75, 831 02 Bratislava 3 (Slovakia); Svec, P. [Institute of Physics, Slovak Academy of Sciences, Dubravska cesta 9, 845 11 Bratislava 45 (Slovakia); Faculty of Materials Science and Technology, Slovak University of Technology, J. Bottu 25, 917 24 Trnava (Slovakia); Janickovic, D.; Illekova, E. [Institute of Physics, Slovak Academy of Sciences, Dubravska cesta 9, 845 11 Bratislava 45 (Slovakia); Plevachuk, Yu. [Ivan Franko National University, Department of Metal Physics, 79005 Lviv (Ukraine)

2011-07-15

Highlights: {yields} New lead-free solder materials based on Sn-Sb-Cu were designed and prepared. {yields} Melting and solidification temperatures of the solders have been determined. {yields} Cu-substrate/solder interaction has been analyzed and quantified. {yields} Phases formed at the solder-substrate interface have been identified. {yields} Composition and soldering atmospheres were correlated with joint strength. - Abstract: Influence of antimony and copper in Sn-Sb-Cu solder on the melting and solidification temperatures and on the microstructure of the interface between the solder and copper substrate after wetting the substrate at 623 K for 1800 s were studied. Microstructure of the interface between the solder and copper substrates in Cu-solder-Cu joints prepared at the same temperature for 1800 s was observed and shear strength of the joints was measured. Influence of the atmosphere - air with the flux and deoxidising N{sub 2} + 10H{sub 2} gas - was taken into account. Thermal stability and microstructure were studied by differential scanning calorimetry (DSC), light microscopy, scanning electron microscopy (SEM) with energy-dispersive spectrometry (EDS) and X-ray diffraction (XRD). Melting and solidification temperatures of the solders were determined. An interfacial transition zone was formed by diffusion reaction between solid copper and liquid solder. At the interface Cu{sub 3}Sn and Cu{sub 6}Sn{sub 5} phases arise. Cu{sub 3}Sn is adjacent to the Cu substrate and its thickness decreases with increasing the amount of copper in solder. Scallop Cu{sub 6}Sn{sub 5} phase is formed also inside the solder drop. The solid solution Sn(Sb) and SbSn phase compose the interior of the solder drop. Shear strength of the joints measured by push-off method decreases with increasing Sb concentration. Copper in the solder shows even bigger negative effect on the strength.
Soldering of Mg Joints Using Zn-Al Solders

Science.gov (United States)

Gancarz, Tomasz; Berent, Katarzyna; Skuza, Wojciech; Janik, Katarzyna

2018-04-01

Magnesium has applications in the automotive and aerospace industries that can significantly contribute to greater fuel economy and environmental conservation. The Mg alloys used in the automotive industry could reduce mass by up to 70 pct, providing energy savings. However, alongside the advantages there are limitations and technological barriers to use Mg alloys. One of the advantages concerns phenomena occurring at the interface when joining materials investigated in this study, in regard to the effect of temperature and soldering time for pure Mg joints. Eutectic Zn-Al and Zn-Al alloys with 0.05 (wt pct) Li and 0.2 (wt pct) Na were used in the soldering process. The process was performed for 3, 5, and 8 minutes of contact, at temperatures of 425 °C, 450 °C, 475 °C, and 500 °C. Selected, solidified solder-substrate couples were cross-sectioned, and their interfacial microstructures were investigated by scanning electron microscopy. The experiment was designed to demonstrate the effect of time, temperature, and the addition of Li and Na on the kinetics of the dissolving Mg substrate. The addition of Li and Na to eutectic Zn-Al caused to improve mechanical properties. Higher temperatures led to reduced joint strength, which is caused by increased interfacial reaction.
Lid heater for glass melter

International Nuclear Information System (INIS)

Phillips, T.D.

1993-01-01

A glass melter having a lid electrode for heating the glass melt radiantly. The electrode comprises a series of INCONEL 690 tubes running above the melt across the melter interior and through the melter walls and having nickel cores inside the tubes beginning where the tubes leave the melter interior and nickel connectors to connect the tubes electrically in series. An applied voltage causes the tubes to generate heat of electrical resistance for melting frit injected onto the melt. The cores limit heat generated as the current passes through the walls of the melter. Nickel bus connection to the electrical power supply minimizes heat transfer away from the melter that would occur if standard copper or water-cooled copper connections were used between the supply and the INCONEL 690 heating tubes. 3 figures
An Overview of Surface Finishes and Their Role in Printed Circuit Board Solderability and Solder Joint Performance

Energy Technology Data Exchange (ETDEWEB)

Vianco, P.T.

1998-10-15

A overview has been presented on the topic of alternative surface finishes for package I/Os and circuit board features. Aspects of processability and solder joint reliability were described for the following coatings: baseline hot-dipped, plated, and plated-and-fused 100Sn and Sn-Pb coatings; Ni/Au; Pd, Ni/Pd, and Ni/Pd/Au finishes; and the recently marketed immersion Ag coatings. The Ni/Au coatings appear to provide the all-around best option in terms of solderability protection and wire bondability. Nickel/Pal ftishes offer a slightly reduced level of performance in these areas that is most likely due to variable Pd surface conditions. It is necessmy to minimize dissolved Au or Pd contents in the solder material to prevent solder joint embrittlement. Ancillary aspects that included thickness measurement techniques; the importance of finish compatibility with conformal coatings and conductive adhesives; and the need for alternative finishes for the processing of non-Pb bearing solders were discussed.
Polyether ether ketone encased monolith frits made of polyether ether ketone tubing with a 0.25 mm opening resulting in an improved separation performance in liquid chromatography.

Science.gov (United States)

Park, Sin Young; Cheong, Won Jo

2016-05-01

Tiny polyether ether ketone encased monolith frits have been prepared by modified catalytic sulfonation of the inner surface of polyether ether tubing (1.6 mm od, 0.25 mm id) followed by modified formation of organic monolith and cutting of the tubing into slices. The frit was placed below the central hole of the column outlet union and supported by a combination of a silica capillary (0.365 mm od, 0.05 mm id) and a polyether ether ketone sleeve (1.6 mm od, 0.38 mm id) tightened with a nut and a ferrule when the column was packed to prevent sinking of the frit element into the union hole (0.25 mm opening) otherwise. The column packed this way with the frits investigated in this study has shown better separation performance owing to the reduced frit volume in comparison to the column packed with a commercial stainless-steel screen frit. This study establishes the strategy of disposable microcolumns in which cheap disposable frits are used whenever the column is re-packed to yield columns of even better chromatographic performance than the columns with commercial frits. © 2016 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.
LSA glass-ceramic tiles made by powder pressing

International Nuclear Information System (INIS)

Figueira, F.C.; Bertan, F.M.; Riella, H.G.; Uggioni, E.; Bernardin, A.M.

2009-01-01

A low cost alternative for the production of glass-ceramic materials is the pressing of the matrix glass powders and its consolidation simultaneously with crystallization in a single stage of sintering. The main objective of this work was to obtain LSA glass ceramics with low thermal expansion, processed by pressing and sintering a ceramic frit powder. The raw materials were homogenized and melted (1480 deg C, 80min), and the melt was poured in water. The glass was chemically (XRF and AAS) and thermally (DTA, 10 deg C/min, air) characterized, and then ground (60min and 120min). The ground powders were characterized (laser diffraction) and compressed (35MPa and 45MPa), thus forming four systems. The compacts were dried (150 deg C, 24h) and sintered (1175 deg C and 1185 deg C, 10 deg C/min). Finally, the glass-ceramics were characterized by microstructural analysis (SEM and XRD), mechanical behavior (σbending) and thermal analysis (α). The best results for thermal expansion were those for the glass-ceramics processed with smaller particle size and greater compaction pressure. (author)
Colorimeter determination of Fe(II)/Fe(III) ratio in glass

International Nuclear Information System (INIS)

Baumann, E.W.; Coleman, C.J.; Karraker, D.G.; Scott, W.H.

1987-01-01

A colorimetric method has been developed to determine the Fe(II)/Fe(III) ratio in glass containing nuclear waste. Fe(II) is stabilized with pentavalent vanadium during dissolution in sulfuric and hydrofluoric acids. The chromogen is FerroZine (Hach Chemical Company), which forms a magenta complex with Fe(II). The two-step color development consists of determining the Fe(II) by adding FerroZine, followed by determining total Fe after the Fe(III) present is reduced with ascorbic acid. The method was validated by analyzing mixtures of ferrous/ferric solutions and nonferrous glass frit, and by comparison with Moessbauer spectroscopy. The effect of gamma radiation was established. The procedure is generally applicable to nonradioactive materials such as minerals and other glasses
High-Temperature Lead-Free Solder Alternatives: Possibilities and Properties

DEFF Research Database (Denmark)

High-temperature solders have been widely used as joining materials to provide stable interconnections that resist a severe thermal environment and also to facilitate the drive for miniaturization. High-lead containing solders have been commonly used as high-temperature solders. The development...... of high-temperature lead-free solders has become an important issue for both the electronics and automobile industries because of the health and environmental concerns associated with lead usage. Unfortunately, limited choices are available as high-temperature lead-free solders. This work outlines...... the criteria for the evaluation of a new high-temperature lead-free solder material. A list of potential ternary high-temperature lead-free solder alternatives based on the Au-Sn and Au-Ge systems is proposed. Furthermore, a comprehensive comparison of the high-temperature stability of microstructures...
Laser-activated protein solder for peripheral nerve repair

Science.gov (United States)

Trickett, Rodney I.; Lauto, Antonio; Dawes, Judith M.; Owen, Earl R.

1995-05-01

A 100 micrometers core optical fiber-coupled 75 mW diode laser operating at a wavelength of 800 nm has been used in conjunction with a protein solder to stripe weld severed rat tibial nerves, reducing the long operating time required for microsurgical nerve repair. Welding is produced by selective laser denaturation of the albumin based solder which contains the dye indocyanine green. Operating time for laser soldering was 10 +/- 5 min. (n equals 20) compared to 23 +/- 9 min. (n equals 10) for microsuturing. The laser solder technique resulted in patent welds with a tensile strength of 15 +/- 5 g, while microsutured nerves had a tensile strength of 40 +/- 10 g. Histopathology of the laser soldered nerves, conducted immediately after surgery, displayed solder adhesion to the outer membrane with minimal damage to the inner axons of the nerves. An in vivo study is under way comparing laser solder repaired tibial nerves to conventional microsuture repair. At the time of submission 15 laser soldered nerves and 7 sutured nerves were characterized at 3 months and showed successful regeneration with compound muscle action potentials of 27 +/- 8 mV and 29 +/- 8 mW respectively. A faster, less damaging and long lasting laser based anastomotic technique is presented.
Features of soldering of molybdenum a lols

International Nuclear Information System (INIS)

Grishin, V.L.; Rybkin, B.V.; Cherkasov, A.F.

1980-01-01

Soldering features of complex-alloy molybdenum alloys were investigated in comparison with alloys based on solid solutions. Soldering features of heterogeneous molybdenum base alloys were investigated using samples of 0.5-1.O mm sheets with the strain of about 95% made of ingots which had been smelted in arc vacuum furnaces. The soldering of samples was carried out in 5x1O -5 mm Hg vacuum using different sources of heating: radiation, electron-ray and contact. It was shown that heat-resisting soldered joints of heterogeneous molybdenum alloys could be produced using zirconium and niobium base solders containing the most effective hardeners of the parent material (titanum, vanadium, tantalum, molybdenum, tungsten). To preserve high mechanical properties of heterogeneous alloys it was expedient to use for welding local heating sources which permitted to decrease considerably temperature- time conditions of the process
The constitutive response of three solder materials

International Nuclear Information System (INIS)

Perez-Bergquist, Alejandro G.; Cao Fang; Perez-Bergquist, Sara J.; Lopez, Mike F.; Trujillo, Carl P.; Cerreta, Ellen K.; Gray, George T.

2012-01-01

Highlights: ► The full constitutive response of three solder materials. ► Test temperatures from −196 °C to 60 °C and strain rates from 10 −3 to >10 3 s −1 . ► Substitutes for leaded solders from a mechanical/microstructural properties view. - Abstract: As increasing worldwide demand for portable consumer electronics drives development of smaller, faster, more powerful electronic devices, components in these devices must become smaller, more precise, and more robust. Often, failure of these devices comes as a result of failure of the package (i.e. when a mobile phone is dropped) and specifically comes as a result of failure of solder interconnects. As a result, stronger more reliable solder materials are needed. In this paper, the constitutive responses of three solder materials (Sn63Pb37, Sn62Pb36Ag2, and Sn96.5Ag3Cu0.5) are analyzed as a function of temperature (−196 °C to 60 °C) and strain rate (10 −3 to >10 3 s −1 ). The lead-free Sn96.5Ag3Cu0.5 possessed the highest yield stress of the three solders at all tested strain rates and temperatures, and all solder microstructures which displayed a mechanical response that was sensitive to temperature exhibited grain coarsening with increasing plastic strain, even at room temperature.
Microstructure evolution and thermomechanical fatigue of solder materials

NARCIS (Netherlands)

Matin, M.A.

2005-01-01

The microelectronics industry is confronted with the new challenge to produce joints with lead-free solder materials replacing classical tin-lead solders in devices used in many fields (e.g. consumer electronics, road transport, aviation, space-crafts, telecommunication). In service, solder

Rutherford backscattering investigation of the corrosion of borosilicate glass

International Nuclear Information System (INIS)

Sales, B.C.; Boatner, L.A.; Naramoto, H.; White, C.W.

1981-10-01

The RBS spectra from Frit 21 borosilicate glasses doped with 5 wt % UO 2 , SrO, or Cs 2 O show that: during the initial stages of leaching (0 to 3 h) there is a substantial (300 to 500%) enhancement in the concentration of U, Sr, Ca, and Ti in the outer surface layer and that this enhancement is accompanied by a large depletion of Na, Si, and Cs; and upon further leaching under static conditions (24 h) the leached surface layer composition is indistinguishable from the unleached surface. Other borosilicate glasses such as PNL 76-68 may eventually show the same behavior if the final equilibrium pH value is greater than 9. The technique of Rutherford backscattering depth profile analysis can be a powerful tool for investigating the initial stages of glass corrosion
Soldering-induced Cu diffusion and intermetallic compound formation between Ni/Cu under bump metallization and SnPb flip-chip solder bumps

Science.gov (United States)

Huang, Chien-Sheng; Jang, Guh-Yaw; Duh, Jenq-Gong

2004-04-01

Nickel-based under bump metallization (UBM) has been widely used as a diffusion barrier to prevent the rapid reaction between the Cu conductor and Sn-based solders. In this study, joints with and without solder after heat treatments were employed to evaluate the diffusion behavior of Cu in the 63Sn-37Pb/Ni/Cu/Ti/Si3N4/Si multilayer structure. The atomic flux of Cu diffused through Ni was evaluated from the concentration profiles of Cu in solder joints. During reflow, the atomic flux of Cu was on the order of 1015-1016 atoms/cm2s. However, in the assembly without solder, no Cu was detected on the surface of Ni even after ten cycles of reflow. The diffusion behavior of Cu during heat treatments was studied, and the soldering-process-induced Cu diffusion through Ni metallization was characterized. In addition, the effect of Cu content in the solder near the solder/intermetallic compound (IMC) interface on interfacial reactions between the solder and the Ni/Cu UBM was also discussed. It is evident that the (Cu,Ni)6Sn5 IMC might form as the concentration of Cu in the Sn-Cu-Ni alloy exceeds 0.6 wt.%.
Laser assisted soldering: microdroplet accumulation with a microjet device.

Science.gov (United States)

Chan, E K; Lu, Q; Bell, B; Motamedi, M; Frederickson, C; Brown, D T; Kovach, I S; Welch, A J

1998-01-01

We investigated the feasibility of a microjet to dispense protein solder for laser assisted soldering. Successive micro solder droplets were deposited on rat dermis and bovine intima specimens. Fixed laser exposure was synchronized with the jetting of each droplet. After photocoagulation, each specimen was cut into two halves at the center of solder coagulum. One half was fixed immediately, while the other half was soaked in phosphate-buffered saline for a designated hydration period before fixation (1 hour, 1, 2, and 7 days). After each hydration period, all tissue specimens were prepared for scanning electron microscopy (SEM). Stable solder coagulum was created by successive photocoagulation of microdroplets even after the soldered tissue exposed to 1 week of hydration. This preliminary study suggested that tissue soldering with successive microdroplets is feasible even with fixed laser parameters without active feedback control.
Thermomechanical fatigue life prediction for several solders

Science.gov (United States)

Wen, Shengmin

Since solder connections operate at high homologous temperature, solders are high temperature materials. This feature makes their mechanical behavior and fatigue phenomena unique. Based on experimental findings, a physical damage mechanism is introduced for solders. The mechanism views the damage process as a series of independent local damage events characterized by the failure of individual grains, while the structural damage is the eventual percolation result of such local events. Fine's dislocation energy density concept and Mura's microcrack initiation theory are adopted to derive the fatigue formula for an individual grain. A physical damage metric is introduced to describe the material with damage. A unified creep and plasticity constitutive model is adopted to simulate the mechanical behavior of solders. The model is cast into a continuum damage mechanics framework to simulate material with damage. The model gives good agreement with the experimental results of 96.5Pb-3.5Sn and 96.5Sn-3.5Ag solders under uniaxial strain-controlled cyclic loading. The model is convenient for implementation into commercial computational packages. Also presented is a fatigue theory with its failure criterion for solders based on physical damage mechanism. By introducing grain orientation into the fatigue formula, an m-N curve (m is Schmid factor) at constant loading condition is suggested for fatigue of grains with different orientations. A solder structure is defined as fatigued when the damage metric reaches a critical threshold, since at this threshold the failed grains may form a cluster and percolate through the structure according to percolation theory. Fatigue data of 96.5Pb-3.5Sn solder bulk specimens under various uniaxial tension tests were analyzed. Results show that the theory gives consistent predictions under broad conditions, while inelastic strain theory does not. The theory is anisotropic with no size limitation to its application, which could be suitable for
Soldering of copper-clad niobium--titanium superconductor composite

International Nuclear Information System (INIS)

Moorhead, A.J.; Woodhouse, J.J.; Easton, D.S.

1977-04-01

When superconductivity is applied to various electrical devices, the joining of the superconducting material and the performance of the joints are generally crucial to the successful operation of the system. Although many techniques are being considered for joining composite superconductors, soldering is the most common. We determined the wetting and flow behavior of various solder and flux combinations on a copper-clad Nb-Ti composite, developed equipment and techniques for soldering and inspection of lap joints, and determined the shear strength of joints at temperatures down to -269 0 C (4 0 K). We studied 15 solders and 17 commercial and experimental fluxes in the wettability and flow tests. A resistance unit was built for soldering test specimens. A series of samples soldered with 80 Pb-20 Sn, 83 Pb-15 Sn-2 Sb, 97.5 Pb-1.5 Ag-1 Sn, 80 In-15 Pb-5 Ag, or 25 In-37.5 Pb-37.5 Sn (wt percent) was inspected by three nondestructive techniques. Through-transmission ultrasound gave the best correlation with nonbond areas revealed in peel tests. Single-lap shear specimens soldered with 97.5 Pb-1.5 Ag-1 Sn had the highest strength (10.44 ksi, 72 MPa) and total elongation (0.074 in., 1.88 mm) at -269 0 C (4 0 K) of four solders tested
Evaluation on the characteristics of tin-silver-bismuth solder

Science.gov (United States)

Xia, Z.; Shi, Y.; Chen, Z.

2002-02-01

Tin-silver-bismuth solder is characterized by its lower melting point, good wetting behavior, and good mechanical property for which it is expected to be a new lead-free solder to replace tin-lead solder. In this article, Sn-3.33Ag-4.83Bi solder was investigated concerning its physical, spreading, and mechanical properties under specific conditions. Cooling curves and DSC results showed that it was close to eutectic composition (m.p. 210° 212 °C). Coefficiency of thermal expansion (CTE) of this solder, between that of PCBs and copper substrates, was beneficial to alleviate the thermal mismatch of the substrates. It was also a good electrical and thermal conductor. Using a rosin-based, mildly activated (RMA) flux, a spreading test indicated that SnAgBi solder paste had good solderability. Meanwhile, the solder had high tensile strength and fracture energy. Its fracture mechanism was a mixture of ductile and brittle fracture morphology. The metallographic and EDAX analyses indicated that it was composed of a tin-based solid solution and some intermetallic compound (IMC) that could strengthen the substrate. However, these large needle-like IMCs would cut the substrate and this resulted in the decreasing of the toughness of the solder.
Control of radioactive waste-glass melters

International Nuclear Information System (INIS)

Bickford, D.F.; Smith, P.K.; Hrma, P.; Bowan, B.W.

1987-01-01

Radioactive waste-glass melters require physical control limits and redox control of glass to assure continuous operation, and maximize production rates. Typical waste-glass melter operating conditions, and waste-glass chemical reaction paths are discussed. Glass composition, batching and melter temperature control are used to avoid the information of phases which are disruptive to melting or reduce melter life. The necessity and probable limitations of control for electric melters with complex waste feed compositions are discussed. Preliminary control limits, their bases, and alternative control methods are described for use in the Defense Waste Processing Facility (DWPF) at the US Department of Energy's Savannah River Plant (SRP), and at the West Valley Demonstration Project (WVDP). Slurries of simulated high level radioactive waste and ground glass frit or glass formers have been isothermally reacted and analyzed to identify the sequence of the major chemical reactions in waste vitrification, and their effect on waste-glass production rates. Relatively high melting rates of waste batches containing mixtures of reducing agents (formic acid, sucrose) and nitrates are attributable to exothermic reactions which occur at critical stages in the vitrification process. The effect of foaming on waste glass production rates is analyzed, and limits defined for existing waste-glass melters, based upon measurable thermophysical properties. Through balancing the high nitrate wastes of the WVDP with reducing agents, the high glass melting rates and sustained melting without foaming required for successful WVDP operations have been demonstrated. 65 refs., 4 figs., 15 tabs
The constitutive response of three solder materials

Energy Technology Data Exchange (ETDEWEB)

Perez-Bergquist, Alejandro G., E-mail: alexpb@lanl.gov [Materials Science and Technology Division, Los Alamos National Laboratory, Mail Stop G755, Los Alamos, NM 87545 (United States); Cao Fang [Exxon Mobil Research and Engineering Company, Annadale, NJ 08801 (United States); Perez-Bergquist, Sara J.; Lopez, Mike F.; Trujillo, Carl P.; Cerreta, Ellen K.; Gray, George T. [Materials Science and Technology Division, Los Alamos National Laboratory, Mail Stop G755, Los Alamos, NM 87545 (United States)

2012-05-25

Highlights: Black-Right-Pointing-Pointer The full constitutive response of three solder materials. Black-Right-Pointing-Pointer Test temperatures from -196 Degree-Sign C to 60 Degree-Sign C and strain rates from 10{sup -3} to >10{sup 3} s{sup -1}. Black-Right-Pointing-Pointer Substitutes for leaded solders from a mechanical/microstructural properties view. - Abstract: As increasing worldwide demand for portable consumer electronics drives development of smaller, faster, more powerful electronic devices, components in these devices must become smaller, more precise, and more robust. Often, failure of these devices comes as a result of failure of the package (i.e. when a mobile phone is dropped) and specifically comes as a result of failure of solder interconnects. As a result, stronger more reliable solder materials are needed. In this paper, the constitutive responses of three solder materials (Sn63Pb37, Sn62Pb36Ag2, and Sn96.5Ag3Cu0.5) are analyzed as a function of temperature (-196 Degree-Sign C to 60 Degree-Sign C) and strain rate (10{sup -3} to >10{sup 3} s{sup -1}). The lead-free Sn96.5Ag3Cu0.5 possessed the highest yield stress of the three solders at all tested strain rates and temperatures, and all solder microstructures which displayed a mechanical response that was sensitive to temperature exhibited grain coarsening with increasing plastic strain, even at room temperature.
Solder wetting behavior enhancement via laser-textured surface microcosmic topography

Energy Technology Data Exchange (ETDEWEB)

Chen, Haiyan [State Key Laboratory of Solidification Processing, Northwestern Polytechnical University, Xi’an 710072 (China); Shaanxi Key Laboratory of Friction Welding Technologies, Xi’an 710072 (China); Peng, Jianke [Shaanxi Key Laboratory of Friction Welding Technologies, Xi’an 710072 (China); Fu, Li, E-mail: fuli@nwpu.edu.cn [State Key Laboratory of Solidification Processing, Northwestern Polytechnical University, Xi’an 710072 (China); Shaanxi Key Laboratory of Friction Welding Technologies, Xi’an 710072 (China); Wang, Xincheng [Shaanxi Key Laboratory of Friction Welding Technologies, Xi’an 710072 (China); Xie, Yan [School of Materials Science and Engineering, Tianjin University, Tianjin 300072 (China)

2016-04-15

Graphical abstract: - Highlights: • The wetting angle of lead free solder on Cu was reduced by surface microstructure. • The wetting form of Sn-Ag-Cu solder on Cu was “non-composite surface”. • The experimental results had a sound fit with the theoretical calculation. - Abstract: In order to reduce or even replace the use of Sn-Pb solder in electronics industry, the laser-textured surface microstructures were used to enhance the wetting behavior of lead free solder during soldering. According to wetting theory and Sn-Ag-Cu lead free solder performance, we calculated and designed four microcosmic structures with the similar shape and different sizes to control the wetting behavior of lead free solder. The micro-structured surfaces with different dimensions were processed on copper plates by fiber femtosecond laser, and the effect of microstructures on wetting behavior was verified experimentally. The results showed that the wetting angle of Sn-Ag-Cu solder on the copper plate with microstructures decreased effectively compared with that on the smooth copper plate. The wetting angles had a sound fit with the theoretical values calculated by wetting model. The novel method provided a feasible route for adjusting the wetting behavior of solders and optimizing solders system.
Effects of waste content of glass waste forms on Savannah River high-level waste disposal costs

International Nuclear Information System (INIS)

McDonell, W.R.; Jantzen, C.M.

1985-01-01

Effects of the waste content of glass waste forms of Savannah River high-level waste disposal costs are evaluated by their impact on the number of waste canisters produced. Changes in waste content affect onsite Defense Waste Processing Facility (DWPF) costs as well as offsite shipping and repository emplacement charges. A nominal 1% increase over the 28 wt % waste loading of DWPF glass would reduce disposal costs by about $50 million for Savannah River wastes generated to the year 2000. Waste form modifications under current study include adjustments of glass frit content to compensate for added salt decontamination residues and increased sludge loadings in the DWPF glass. Projected cost reductions demonstrate significant incentives for continued optimization of the glass waste loadings. 13 refs., 3 figs., 3 tabs
Utilization of Pb-free solders in MEMS packaging

Science.gov (United States)

Selvaduray, Guna S.

2003-01-01

Soldering of components within a package plays an important role in providing electrical interconnection, mechanical integrity and thermal dissipation. MEMS packages present challenges that are more complex than microelectronic packages because they are far more sensitive to shock and vibration and also require precision alignment. Soldering is used at two major levels within a MEMS package: at the die attach level and at the component attach level. Emerging environmental regulations worldwide, notably in Europe and Japan, have targeted the elimination of Pb usage in electronic assemblies, due to the inherent toxicity of Pb. This has provided the driving force for development and deployment of Pb-free solder alloys. A relatively large number of Pb-free solder alloys have been proposed by various researchers and companies. Some of these alloys have also been patented. After several years of research, the solder alloy system that has emerged is based on Sn as a major component. The electronics industry has identified different compositions for different specific uses, such as wave soldering, surface mount reflow, etc. The factors that affect choice of an appropriate Pb-free solder can be divided into two major categories, those related to manufacturing, and those related to long term reliability and performance.
Mechanical properties of Bi-In-Zn/ Cu solder joint system

International Nuclear Information System (INIS)

Ervina Efzan Mohd Noor; Mohammed Noori Ridha; Ahmad Badri Ismail; Nurulakmal Mohd Sharif; Kuan Yew Cheong; Tadashi Ariga; Zuhailawati Hussain

2009-01-01

Full text: In recent years, the pollution of environment from lead (Pb) and Pb-containing compounds in microelectronic devices attracts more and more attentions in academia and industry; the lead-free solder alloys begin to replace the lead-based solders in packaging process of some devices and components. In this works, microstructure and mechanical properties of different reflow temperature (80, 100, 120 and 140 degree Celsius) for solder joints on shear strength of Bi-In-Zn lead free solder with low melting temperature of 60 degree Celsius on Cu solder joint has been investigated. This paper will compared the mechanical properties of the Bi-In-Zn lead-free solder alloys with current lead-free solder, Sn-Ag-Cu solder alloy. The fracture surface analyses have been observed by Optical Microscope and were investigated by Scanning Electron Microscope (SEM) and Energy Dispersive X-ray (EDX) and proved it by X-ray diffraction (XRD). (author)
Correlation Between Pin Misalignment and Crack Length in THT Solder Joints

Directory of Open Access Journals (Sweden)

Molnar A.

2017-06-01

Full Text Available In this manuscript, correlations were searched for between pin misalignments relative to PCB bores and crack propagation after cyclic thermal shock tests in THT solder joints produced from lead-free solder alloys. In total, 7 compositions were examined including SAC solders with varying Ag, Cu and Ni contents. The crack propagation was initiated by cyclic thermal shock tests with 40°C / +125°C temperature profiles. Pin misalignments relative to the bores were characterized with three attributes obtained from one section of the examined solder joints. Cracks typically originated at the solder/pin or solder/bore interfaces and propagated within the solder. It was shown that pin misalignments did not have an effect on crack propagation, thus, the solder joints’ lifetime.
Albumin solder covalently bound to a polymer membrane: New approach to improve binding strength in laser tissue soldering in-vitro.

Science.gov (United States)

Hiebl, B; Ascher, L; Luetzow, K; Kratz, K; Gruber, C; Mrowietz, C; Nehring, M E; Lendlein, A; Franke, R-P; Jung, F

2018-01-01

Laser tissue soldering (LTS) based on indocyanine green (ICG)-mediated heat-denaturation of proteins might be a promising alternative technique for micro-suturing, but up to now the problem of too weak shear strength of the solder welds in comparison to sutures is not solved. Earlier reports gave promising results showing that solder supported by carrier materials can enhance the cohesive strength of the liquid solder. In these studies, the solder was applied to the carriers by dip coating. Higher reliability of the connection between the solder and the carrier material is expected when the solder is bound covalently to the carrier material. In the present study a poly(ether imide) (PEI) membrane served as carrier material and ICG-supplemented albumin as solder substrate. The latter was covalently coupled to the carrier membrane under physiological conditions to prevent structural protein changes. As laser source a diode continuous-wave laser emitting at 808 nm with intensities between 250 mW and 1500 mW was utilized. The albumin functionalized carrier membrane was placed onto the tunica media of explanted pig thoracic aortae forming an overlapping area of approximately 0.5×0.5 cm2. All tests were performed in a dry state to prevent laser light absorption by water. Infrared spectroscopy, spectro-photometrical determination of the secondary and primary amine groups after acid orange II staining, contact angle measurements, and atomic force microscopy proved the successful functionalization of the PEI membrane with albumin. A laser power of 450 mW LTS could generate a membrane-blood vessel connection which was characterized by a shear strength of 0.08±0.002 MPa, corresponding to 15% of the tensile strength of the native blood vessel. Theoretically, an overlapping zone of 4.1 mm around the entire circumference of the blood vessel could have provided shear strength of the PEI membrane-blood vessel compound identical to the tensile strength of the native
Integration of environmentally compatible soldering technologies for waste minimization

International Nuclear Information System (INIS)

Hosking, F.M.

1992-01-01

There has been a concentrated effort throughout the international microelectronics industry to phase out chlorofluorocarbon (CFC) materials and alleviate the serious problem of ozone depletion created by the release of CFCS. The development of more environmentally compatible manufacturing technologies is the cornerstone of this effort. Alternative materials and processes for cleaning and soldering have received special attention. Electronic. soldering typically utilizes rosin-based fluxes to promote solder wettability. Flux residues must be removed from the soldered parts when high product reliability is essential. Halogenated or CFC solvents have been the principle chemicals used to clean the residues. With the accelerated push to eliminate CFCs in the US by 1995, CFC-free solvents, aqueous-based cleaning, water soluble or ''no clean'' fluxes, and fluxless soldering technologies are being developed and quickly integrated into manufacturing practice. Sandia's Center for Solder Science and Technology has been ch g a variety of fluxless and alternative soldering technologies for DOE's waste minimization program. The work has focused on controlled atmosphere, laser, and ultrasonic fluxless soldering, protective metallic and organic coatings, and fluxes which have water soluble or low solids-based chemistries. With the increasing concern that Pb will also be banned from electronic soldering, Sandia has been characterizing the wetting, aging, and mechanical properties of Pb-fire solder alloys. The progress of these integrated studies will be discussed. Their impact on environmentally compatible manufacturing will be emphasized. Since there is no universal solution to the various environmental, safety, and health issues which currently face industry, the proposed technologies offer several complementary materials and processing options from which one can choose
Efforts to Develop a 300°C Solder

Energy Technology Data Exchange (ETDEWEB)

Norann, Randy A [Perma Works LLC

2015-01-25

This paper covers the efforts made to find a 300°C electrical solder solution for geothermal well monitoring and logging tools by Perma Works LLC. This paper covers: why a high temperature solder is needed, what makes for a good solder, testing flux, testing conductive epoxy and testing intermetallic bonds. Future areas of research are suggested.
Strength of joints brazed with two-phase solders

International Nuclear Information System (INIS)

Shnyakin, N.S.; Parfenova, L.V.; Ekatova, A.S.; Prilepskaya, I.V.

1976-01-01

Dependence of the structure and strength of soldered joints upon a gap size in case of 1Kh18N10T stainless steel soldering with a double-phase solder of Ni-Zn-Cu system is described. Butt and lap joints have been subjected to soldering with gas-flame and induction heating. The optimum conditions of the solder crystallization are determined with wedge-gap samples. The studies show that the character of distribution of a fusible β-phase in metal depends upon a gap size. With gaps up to 0.1 mm the β-phase enriched with a fusible component (zinc) runs as a continuous thin interlayer in the middle of the seam. As a result of zinc evaporation from the β-phase this interlayer becomes internally oxidized. After the sample is broken an oxidized fracture gives one the impression of a poor fusion in the middle part of the joint. The ultimate strength of butt joints is 15-20 kgf/sq.mm. A value of thermal expansion of 1Kh18N10T steel samples, 1-5 mm thick, has been experimentally determined for butt soldering. The elongation of two halves of the sample is measured by an indicator and proved to be 0.89 mm for a 50x50x2 mm sample at a soldering temperature of 1.100 deg C. The paper presents methods for the calculation of an optimal gap value for butt soldering with a local gas-flame and induction heating
Development Of Glass Matrices For HLW Radioactive Wastes

International Nuclear Information System (INIS)

Jantzen, C.

2010-01-01

Vitrification is currently the most widely used technology for the treatment of high level radioactive wastes (HLW) throughout the world. Most of the nations that have generated HLW are immobilizing in either borosilicate glass or phosphate glass. One of the primary reasons that glass has become the most widely used immobilization media is the relative simplicity of the vitrification process, e.g. melt waste plus glass forming frit additives and cast. A second reason that glass has become widely used for HLW is that the short range order (SRO) and medium range order (MRO) found in glass atomistically bonds the radionuclides and governs the melt properties such as viscosity, resistivity, sulphate solubility. The molecular structure of glass controls contaminant/radionuclide release by establishing the distribution of ion exchange sites, hydrolysis sites, and the access of water to those sites. The molecular structure is flexible and hence accounts for the flexibility of glass formulations to waste variability. Nuclear waste glasses melt between 1050-1150 C which minimizes the volatility of radioactive components such as Tc 99 , Cs 137 , and I 129 . Nuclear waste glasses have good long term stability including irradiation resistance. Process control models based on the molecular structure of glass have been mechanistically derived and have been demonstrated to be accurate enough to control the world's largest HLW Joule heated ceramic melter in the US since 1996 at 95% confidence.
ESCA studies on leached glass forms

International Nuclear Information System (INIS)

Dawkins, B.G.

1979-01-01

Electron Spectroscopy for Chemical Analysis (ESCA) results for frit, obsidian, NBS standard, and Savannah River Laboratory (SRL) glass forms that have been subjected to cumulative water leachings of 36 hours show that [Na] exhibits the largest and fastest change of all the elements observed. Leaching of surface Na occurred within minutes. Surface Na depletion increased with leach time. Continuous x-ray irradiation and argon ion milling induced Na mobility, precluding semiquantitative ESCA analysis at normal operating temperatures. However, the sample stage has been equipped with a liquid nitrogen supply and alkali mobility should be eliminated in future work
Safer Soldering Guidelines and Instructional Resources

Science.gov (United States)

Love, Tyler S.; Tomlinson, Joel

2018-01-01

Soldering is a useful and necessary process for many classroom, makerspace, Fab Lab, technology and engineering lab, and science lab activities. As described in this article, soldering can pose many safety risks without proper engineering controls, standard operating procedures, and direct instructor supervision. There are many safety hazards…

Lead-free solder technology transfer from ASE Americas

Energy Technology Data Exchange (ETDEWEB)

FTHENAKIS,V.

1999-10-19

To safeguard the environmental friendliness of photovoltaics, the PV industry follows a proactive, long-term environmental strategy involving a life-of-cycle approach to prevent environmental damage by its processes and products from cradle to grave. Part of this strategy is to examine substituting lead-based solder on PV modules with other solder alloys. Lead is a toxic metal that, if ingested, can damage the brain, nervous system, liver and kidneys. Lead from solder in electronic products has been found to leach out from municipal waste landfills and municipal incinerator ash was found to be high in lead also because of disposed consumer electronics and batteries. Consequently, there is a movement in Europe and Japan to ban lead altogether from use in electronic products and to restrict the movement across geographical boundaries of waste containing lead. Photovoltaic modules may contain small amounts of regulated materials, which vary from one technology to another. Environmental regulations impact the cost and complexity of dealing with end-of-life PV modules. If they were classified as hazardous according to Federal or State criteria, then special requirements for material handling, disposal, record-keeping and reporting would escalate the cost of decommissioning the modules. Fthenakis showed that several of today's x-Si modules failed the US-EPA Toxicity Characteristic Leaching Procedure (TCLP) for potential leaching of Pb in landfills and also California's standard on Total Threshold Limit Concentration (TTLC) for Pb. Consequently, such modules may be classified as hazardous waste. He highlighted potential legislation in Europe and Japan which could ban or restrict the use of lead and the efforts of the printed-circuit industries in developing Pb-free solder technologies in response to such expected legislation. Japanese firms already have introduced electronic products with Pb-free solder, and one PV manufacturer in the US, ASE Americas has used a
Influence of Co and W powders on viscosity of composite solders during soldering of specially shaped diamond-abrasive tools

Science.gov (United States)

Sokolov, E. G.; Aref’eva, S. A.; Svistun, L. I.

2018-03-01

The influence of Co and W powders on the structure and the viscosity of composite solders Sn-Cu-Co-W used for the manufacture of the specially shaped diamond tools has been studied. The solders were obtained by mixing the metallic powders with an organic binder. The mixtures with and without diamonds were applied to steel rollers and shaped substrates. The sintering was carried out in a vacuum at 820 ° C with time-exposure of 40 minutes. The influence of Co and W powders on the viscosity solders was evaluated on the basis of the study of structures and according to the results of sintering specially shaped diamond tools. It was found that to provide the necessary viscosity and to obtain the uniform diamond-containing layers on the complex shaped surfaces, Sn-Cu-Co-W solder should contain 27–35 vol % of solid phase. This is achieved with a total solder content of 24–32 wt % of cobalt powder and 7 wt % of tungsten powder.
On-line plutonium measurement by alpha counting using a silica glass sensor

International Nuclear Information System (INIS)

Edeline, J.C.; Furgolle, B.

1980-01-01

Some cerium activated high purity silica glasses are good sensors for ionising particles counting. These sensors may be used for measuring plutonium concentrations in corrosive solutions which are typical in reprocessing operations. The thickness of the sensor has been reduced to minimize beta sensitivity. The thin sensor is hold by molecular adhesion to a thick glass mount which is soldered to the stainless steel sample cell [fr
The influence of silver content on structure and properties of Sn–Bi–Ag solder and Cu/solder/Cu joints

Energy Technology Data Exchange (ETDEWEB)

Šebo, P. [Institute of Materials and Machine Mechanics, Slovak Academy of Sciences, Račianska 75, 831 02 Bratislava 3 (Slovakia); Švec, P. Sr., E-mail: Peter.Svec@savba.sk [Institute of Physics, Slovak Academy of Sciences, Dúbravská cesta 9, 845 11 Bratislava 45 (Slovakia); Faculty of Materials Science and Technology, Slovak University of Technology, J. Bottu 25, 917 24 Trnava (Slovakia); Janičkovič, D.; Illeková, E. [Institute of Physics, Slovak Academy of Sciences, Dúbravská cesta 9, 845 11 Bratislava 45 (Slovakia); Zemánková, M. [Institute of Materials and Machine Mechanics, Slovak Academy of Sciences, Račianska 75, 831 02 Bratislava 3 (Slovakia); Plevachuk, Yu. [Ivan Franko National University, Department of Metal Physics, 79005 Lviv (Ukraine); Sidorov, V. [Ural State Pedagogical University, Cosmonavtov 26, 620017 Ekaterinburg (Russian Federation); Švec, P. [Institute of Physics, Slovak Academy of Sciences, Dúbravská cesta 9, 845 11 Bratislava 45 (Slovakia)

2013-06-01

The effect of silver content on structure and properties of Sn{sub 100−x}Bi{sub 10}Ag{sub x} (x=3–10 at%) lead-free solder and Cu–solder–Cu joints was investigated. The microstructure of the solder in both bulk and rapidly solidified ribbon forms was analyzed by scanning electron microscopy (SEM) and X-ray diffraction. The peculiarities in melting kinetic, studied by differential scanning calorimetry (DSC), and silver influence on it are described and discussed. The wetting of a copper substrate was examined by the sessile drop method in the temperature range of 553–673 K in air and deoxidizing gas (N{sub 2}+10%H{sub 2}) at atmospheric pressure. Cu–solder–Cu joints were also prepared in both atmospheres, and their shear strength was measured by the push-off method. The produced solders consisted of tin, bismuth and Ag{sub 3}Sn phases. The product of the interaction between the solder and the copper substrate consists of two phases: Cu{sub 3}Sn, which is adjacent to the substrate, and a Cu{sub 6}Sn{sub 5} phase. The wetting angle in air increased slightly as the silver concentration in the solder increased. Wetting of the copper substrate in N{sub 2}+10H{sub 2} gas shows the opposite tendency: the wetting angle slightly decreased as the silver content in the solder increased. The shear strength of the joints prepared in air (using flux) tends to decrease with increasing production temperature and increasing silver content in the solder. The equivalent decrease in the shear strength of the joints prepared in N{sub 2}+10H{sub 2} is more apparent.
Fatigue and thermal fatigue of Pb-Sn solder joints

International Nuclear Information System (INIS)

Frear, D.; Grivas, D.; McCormack, M.; Tribula, D.; Morris, J.W. Jr.

1987-01-01

This paper presents a fundamental investigation of the fatigue and thermal fatigue characteristics, with an emphasis on the microstructural development during fatigue, of Sn-Pb solder joints. Fatigue tests were performed in simple shear on both 60Sn-40Pb and 5Sn-95Pb solder joints. Isothermal fatigue tests show increasing fatigue life of 60Sn-40Pb solder joints with decreasing strain and temperature. In contrast, such behavior was not observed in the isothermal fatigue of 5Sn-95Pb solder joints. Thermal fatigue results on 60Sn-40Pb solder cycled between -55 0 C and 125 0 C show that a coarsened region develops in the center of the joint. Both Pb-rich and Sn-rich phases coarsen, and cracks form within these coarsened regions. The failure mode 60Sn-40Pb solder joints in thermal and isothermal fatigue is similar: cracks form intergranularly through the Sn-rich phase or along Sn/Pb interphase boundaries. Extensive cracking is found throughout the 5Sn-95Pb joint for both thermal and isothermal fatigue. In thermal fatigue the 5Sn-95Pb solder joints failed after fewer cycles than 60Sn-40Pb
Durability of glasses from the Hg-doped Integrated DWPF Melter System (IDMS) campaign

International Nuclear Information System (INIS)

Jantzen, C.M.

1992-01-01

The Integrated DWPF Melter System (IDMS) for the vitrification of high-level radioactive wastes is designed and constructed to be a 1/9th scale prototype of the full scale Defense Waste Processing Facility (DWPF) melter. The IDMS facility is the first engineering scale melter system capable of processing mercury, and flowsheet levels of halides and noble metals. In order to determine the effects of mercury on the feed preparation process, the off-gas chemistry, glass melting behavior, and glass durability, a three-run mercury (Hg) campaign was conducted. The glasses produced during the Hg campaign were composed of Batch 1 sludge, simulated precipitate hydrolysis aqueous product (PHA) from the Precipitate Hydrolysis Experimental Facility (PHEF), and Frit 202. The glasses were produced using the DWPF process/product models for glass durability, viscosity, and liquidus. The durability model indicated that the glasses would all be more durable than the glass qualified in the DWPF Environmental Assessment (EA). The glass quality was verified by performing the Product Consistency Test (PCT) which was designed for glass durability testing in the DWPF
A flip chip process based on electroplated solder bumps

Science.gov (United States)

Salonen, J.; Salmi, J.

1994-01-01

Compared to wire bonding and TAB, flip chip technology using solder joints offers the highest pin count and packaging density and superior electrical performance. The chips are mounted upside down on the substrate, which can be made of silicon, ceramic, glass or - in some cases - even PCB. The extra processing steps required for chips are the deposition of a suitable thin film metal layer(s) on the standard Al pad and the formation of bumps. Also, the development of new fine line substrate technologies is required to utilize the full potential of the technology. In our bumping process, bump deposition is done by electroplating, which was chosen for its simplicity and economy. Sputter deposited molybdenum and copper are used as thin film layers between the aluminum pads and the solder bumps. A reason for this choice is that the metals can be selectively etched after bumping using the bumps as a mask, thus circumventing the need for a separate mask for etching the thin film metals. The bumps are electroplated from a binary Pb-Sn bath using a thick liquid photoresist. An extensively modified commercial flip chip bonder is used for alignment and bonding. Heat assisted tack bonding is used to attach the chips to the substrate, and final reflow joining is done without flux in a vacuum furnace.
Nano-soldering to single atomic layer

Science.gov (United States)

Girit, Caglar O [Berkeley, CA; Zettl, Alexander K [Kensington, CA

2011-10-11

A simple technique to solder submicron sized, ohmic contacts to nanostructures has been disclosed. The technique has several advantages over standard electron beam lithography methods, which are complex, costly, and can contaminate samples. To demonstrate the soldering technique graphene, a single atomic layer of carbon, has been contacted, and low- and high-field electronic transport properties have been measured.
Soldering formalism in noncommutative field theory: a brief note

International Nuclear Information System (INIS)

Ghosh, Subir

2004-01-01

In this Letter, I develop the soldering formalism in a new domain--the noncommutative planar field theories. The soldering mechanism fuses two distinct theories showing opposite or complimentary properties of some symmetry, taking into account the interference effects. The above mentioned symmetry is hidden in the composite (or soldered) theory. In the present work it is shown that a pair of noncommutative Maxwell-Chern-Simons theories, having opposite signs in their respective topological terms, can be consistently soldered to yield the Proca model (Maxwell theory with a mass term) with corrections that are at least quadratic in the noncommutativity parameter. We further argue that this model can be thought of as the noncommutative generalization of the Proca theory of ordinary spacetime. It is well known that abelian noncommutative gauge theory bears a close structural similarity with non-abelian gauge theory. This fact is manifested in a non-trivial way if the present Letter is compared with existing literature, where soldering of non-abelian models are discussed. Thus the present work further establishes the robustness of the soldering programme. The subtle role played by gauge invariance (or the lack of it), in the above soldering process, is revealed in an interesting way
A new method for soldering particle-reinforced aluminum metal matrix composites

Energy Technology Data Exchange (ETDEWEB)

Lu, Jinbin; Mu, Yunchao [Zhongyuan University of Technology, Zhengzhou 450007 (China); Luo, Xiangwei [Zhengzhou University, Zhengzhou 450002 (China); Niu, Jitai, E-mail: niujitai@163.com [Zhongyuan University of Technology, Zhengzhou 450007 (China)

2012-12-01

Highlights: Black-Right-Pointing-Pointer Soldering of 55% SiCp/Al composite and Kovar is first achieved in the world. Black-Right-Pointing-Pointer The nickel plating is required on the surface of the composites before soldering. Black-Right-Pointing-Pointer Low welding temperature is set to avoid overheating of the matrix. Black-Right-Pointing-Pointer Chemical and metallurgical bonding of composites and Kovar is carried out. Black-Right-Pointing-Pointer High tension strength of 225 MPa in soldering seam has been obtained. - Abstract: Soldering of aluminum metal matrix composites (Al-SiC) to other structural materials, or even to themselves, has proved unsuccessful mainly due to the poor wetting of these composites by conventional soldering alloys. This paper reports a new approach, which improves the wetting properties of these composites by molting solder alloys to promote stronger bonds. The new approach relies on nickel-plating of the composite's faying surface prior to application of a solder alloy. Based on this approach, an aluminum metal matrix composite containing 55 vol.% SiC particles is successfully soldered to a Fe-Ni-Co alloy (commercially known as Kovar 4J29). The solder material is a zinc-based alloy (Zn-Cd-Ag-Cu) with a melting point of about 400 Degree-Sign C. Microscopic examinations of the aluminum metal matrix composites (Al-MMCs)-Kovar interfaces show that the nickel-plating, prior to soldering, could noticeably enhance the reaction between the molten solder and composites. The fractography of the shear-tested samples revealed that fracture occurs within the composite (i.e. cohesive failure), indicating a good adhesion between the solder alloy and the Al-SiC composite.
A new method for soldering particle-reinforced aluminum metal matrix composites

International Nuclear Information System (INIS)

Lu, Jinbin; Mu, Yunchao; Luo, Xiangwei; Niu, Jitai

2012-01-01

Highlights: ► Soldering of 55% SiCp/Al composite and Kovar is first achieved in the world. ► The nickel plating is required on the surface of the composites before soldering. ► Low welding temperature is set to avoid overheating of the matrix. ► Chemical and metallurgical bonding of composites and Kovar is carried out. ► High tension strength of 225 MPa in soldering seam has been obtained. - Abstract: Soldering of aluminum metal matrix composites (Al–SiC) to other structural materials, or even to themselves, has proved unsuccessful mainly due to the poor wetting of these composites by conventional soldering alloys. This paper reports a new approach, which improves the wetting properties of these composites by molting solder alloys to promote stronger bonds. The new approach relies on nickel-plating of the composite's faying surface prior to application of a solder alloy. Based on this approach, an aluminum metal matrix composite containing 55 vol.% SiC particles is successfully soldered to a Fe–Ni–Co alloy (commercially known as Kovar 4J29). The solder material is a zinc-based alloy (Zn–Cd–Ag–Cu) with a melting point of about 400 °C. Microscopic examinations of the aluminum metal matrix composites (Al-MMCs)–Kovar interfaces show that the nickel-plating, prior to soldering, could noticeably enhance the reaction between the molten solder and composites. The fractography of the shear-tested samples revealed that fracture occurs within the composite (i.e. cohesive failure), indicating a good adhesion between the solder alloy and the Al–SiC composite.
Corrosion behaviors of a glass-bonded sodalite ceramic waste form and its constituents

International Nuclear Information System (INIS)

Lewis, M. A.; Ebert, W. L.; Morss, L.

1999-01-01

A ceramic waste form (CWF) of glass bonded sodalite is being developed as a waste form for the long-term immobilization of fission products and transuranic elements from the U.S. Department of Energy's activities on spent nuclear fuel conditioning. A durable waste form was prepared by hot isostatic pressing (HIP) a mixture of salt-loaded zeolite powders and glass frit. During HIP the zeolite is converted to sodalite, and the resultant CWF is been completed for durations of up to 182 days. Four dissolution modes were identified: dissolution of free salt, dissolution of the aluminosilicate matrix of sodalite and the accompanying dissolution of occluded salt, dissolution of the boroaluminosilicate matrix of the glass, and ion exchange. Synergies inherent to the CWF were identified by comparing the results of the tests with pure glass and sodalite with those of the composite CWF
Parametric testing of a DWPF glass

International Nuclear Information System (INIS)

Bazan, F.; Rego, J.

1985-03-01

A series of tests has been performed to characterize the chemical stability of a DWPF borosilicate glass sample as part of the Waste Package Task of the Nevada Nuclear Waste Storage Investigations (NNWSI) Project. This material was prepared at the Savannah River Laboratory for the purpose of testing the 165-frit matrix doped with a simulated nonradioactive waste. All tests were conducted at 90 0 C using deionized water and J-13 water (a tuffaceous formation ground water). In the deionized water tests, both monoliths and crushed glass were tested at various ratios of surface area of the sample to volume of water in order to compare leach rates for different sample geometries or leaching times. Effects on the leach rates as a result of the presence of crushed tuff and stainless steel material were also investigated in the tests with J-13 water. 3 refs., 12 figs., 7 tabs
DEVELOPMENT OF GLASS MATRICES FOR HLW RADIOACTIVE WASTES

Energy Technology Data Exchange (ETDEWEB)

Jantzen, C.

2010-03-18

Vitrification is currently the most widely used technology for the treatment of high level radioactive wastes (HLW) throughout the world. Most of the nations that have generated HLW are immobilizing in either borosilicate glass or phosphate glass. One of the primary reasons that glass has become the most widely used immobilization media is the relative simplicity of the vitrification process, e.g. melt waste plus glass forming frit additives and cast. A second reason that glass has become widely used for HLW is that the short range order (SRO) and medium range order (MRO) found in glass atomistically bonds the radionuclides and governs the melt properties such as viscosity, resistivity, sulphate solubility. The molecular structure of glass controls contaminant/radionuclide release by establishing the distribution of ion exchange sites, hydrolysis sites, and the access of water to those sites. The molecular structure is flexible and hence accounts for the flexibility of glass formulations to waste variability. Nuclear waste glasses melt between 1050-1150 C which minimizes the volatility of radioactive components such as Tc{sup 99}, Cs{sup 137}, and I{sup 129}. Nuclear waste glasses have good long term stability including irradiation resistance. Process control models based on the molecular structure of glass have been mechanistically derived and have been demonstrated to be accurate enough to control the world's largest HLW Joule heated ceramic melter in the US since 1996 at 95% confidence.
Small-scale, joule-heated melting of Savannah River Plant waste glass. I. Factors affecting large-scale vitrification tests

International Nuclear Information System (INIS)

Plodinec, M.J.; Chismar, P.H.

1979-10-01

A promising method of immobilizing SRP radioactive waste solids is incorporation in borosilicate glass. In the reference vitrification process, called joule-heated melting, a mixture of glass frit and calcined waste is heated by passage of an electric current. Two problems observed in large-scale tests are foaming and formation of an insoluble slag. A small joule-heated melter was designed and built to study problems such as these. This report describes the melter, identifies factors involved in foaming and slag formation, and proposes ways to overcome these problems
Thermomechanical behavior of tin-rich (lead-free) solders

Science.gov (United States)

Sidhu, Rajen Singh

In order to adequately characterize the behavior of ball-grid-array (BGA) Pb-free solder spheres in electronic devices, the microstructure and thermomechanical behavior need to be studied. Microstructure characterization of pure Sn, Sn-0.7Cu, Sn-3.5Ag, and Sn-3.9Ag-0.7Cu alloys was conducted using optical microscopy, scanning electron microscopy, transmission electron microscopy, image analysis, and a novel serial sectioning 3D reconstruction process. Microstructure-based finite-element method (FEM) modeling of deformation in Sn-3.5Ag alloy was conducted, and it will be shown that this technique is more accurate when compared to traditional unit cell models for simulating and understanding material behavior. The effect of cooling rate on microstructure and creep behavior of bulk Sn-rich solders was studied. The creep behavior was evaluated at 25, 95, and 120°C. Faster cooling rates were found to increase the creep strength of the solders due to refinement of the solder microstructure. The creep behavior of Sn-rich single solder spheres reflowed on Cu substrates was studied at 25, 60, 95, and 130°C. Testing was conducted using a microforce testing system, with lap-shear geometry samples. The solder joints displayed two distinct creep behaviors: (a) precipitation-strengthening (Sn-3.5Ag and Sn-3.9Ag-0.7Cu) and (b) power law creep accommodated by grain boundary sliding (GBS) (Sn and Sn-0.7Cu). The relationship between microstructural features (i.e. intermetallic particle size and spacing), stress exponents, threshold stress, and activation energies are discussed. The relationship between small-length scale creep behavior and bulk behavior is also addressed. To better understand the damage evolution in Sn-rich solder joints during thermal fatigue, the local damage will be correlated to the cyclic hysteresis behavior and crystal orientations present in the Sn phase of solder joints. FEM modeling will also be utilized to better understand the macroscopic and local
30 CFR 77.1916 - Welding, cutting, and soldering; fire protection.

Science.gov (United States)

2010-07-01

... 30 Mineral Resources 1 2010-07-01 2010-07-01 false Welding, cutting, and soldering; fire... OF UNDERGROUND COAL MINES Slope and Shaft Sinking § 77.1916 Welding, cutting, and soldering; fire protection. (a) One portable fire extinguisher shall be provided where welding, cutting, or soldering with...
The influence of penetrating gamma radiation on the reaction of simulated nuclear waste glass in tuff groundwater

International Nuclear Information System (INIS)

Ebert, W.L.; Bates, J.K.; Abrajano, T.A. Jr.; Gerding, T.J.

1989-01-01

Static leaching experiments have been performed to determine the influence of penetrating gamma radiation on the reaction of simulated nuclear waste glass in tuff groundwater at 90/degree/C. Both the leachates and the reacted glass monoliths were analyzed to characterize the reaction. Radiation was seen to acidify the leachates, but the high bicarbonate content of the groundwater prevented the pHs from dropping below 6.4. The glass reaction tended to raise the pH. Glass based on SRL 165 black frit and PNL 76-68 glass compositions were leached. The SRL 165 type glasses were quite durable and unaffected by radiation [NL(B) /approximately/4 g/m 2 after 278 days at all exposure rates]. The PNL 76-68 glasses were much less durable, with the durability decreasing as the exposure rate was increased [NL(B) was about 20 g/m 2 after 278 days at 1 /times/ 10 3 R/h for both ATM-1c and ATM-8 glasses]. 8 refs., 5 figs
Initial demonstration of DWPF process and product control strategy using actual radioactive waste

International Nuclear Information System (INIS)

Andrews, M.K.; Bibler, N.E.; Jantzen, C.M.; Beam, D.C.

1991-01-01

The Defense Waste Processing Facility at the Savannah River Site (SRS) will vitrify high-level nuclear waste into borosilicate glass. The waste will be mixed with properly formulated glass-making frit and fed to a melter at 1150 degrees C. Process control and product quality are ensured by proper control of the melter feed composition. Algorithms have been developed to predict the processability of the melt and the durability of the final glass based on this feed composition. To test these algorithms, an actual radioactive waste contained in a shielded facility at SRS was analyzed and a frit composition formulated using a simple computer spreadsheet which contained the algorithms. This frit was then mixed with the waste and the resulting slurry fed to a research scale joule-heated melter operated remotely. Approximately 24 kg of glass were successfully prepared. This paper will describe the frit formulation, the vitrification process, and the glass durability
Glass melter assembly for the Hanford Waste Vitrification Plant

International Nuclear Information System (INIS)

Chen, A.E.; Russell, A.; Shah, K.R.; Kalia, J.

1993-01-01

The Hanford Waste Vitrification Plant (HWVP) is designed to solidify high level radioactive waste by converting it into stable borosilicate after mixing with glass frit and water. The heart of this conversion process takes place in the glass melter. The life span of the existing melter is limited by the possible premature failure of the heater assembly, which is not remotely replaceable, in the riser and pour spout. A goal of HWVP Project is to design remotely replaceable riser and pour spout heaters so that the useful life of the melter can be prolonged. The riser pour spout area is accessible only by the canyon crane and impact wrench. It is also congested with supporting frame members, service piping, electrode terminals, canister positioning arm and other various melter components. The visibility is low and the accessibility is limited. The problem is further compounded by the extreme high temperature in the riser core and the electrical conductive nature of the molten glass that flows through it

Mechanical properties of soldered joints of niobium base alloys

International Nuclear Information System (INIS)

Grishin, V.L.

1980-01-01

Mechanical properties of soldered joints of niobium alloys widely distributed in industry: VN3, VN4, VN5A, VN5AE, VN5AEP etc., 0.6-1.2 mm thick are investigated. It is found out that the usage of zirconium-vanadium, titanium-tantalum solders for welding niobium base alloys permits to obtain soldered joints with satisfactory mechanical properties at elevated temperatures
A Corrosion Investigation of Solder Candidates for High-Temperature Applications

DEFF Research Database (Denmark)

Chidambaram, Vivek; Hald, John; Ambat, Rajan

2009-01-01

The step soldering approach is being employed in the Multi-Chip module (MCM) technology. High lead containing alloys is one of the solders currently being used in this approach. Au-Sn and Au-Ge based candidate alloys have been proposed as alternative solders for this application. In this work...
Microstructurally Adaptive Constitutive Relations and Reliability Assessment Protocols for Lead Free Solder

Science.gov (United States)

2015-05-05

under bump metallurgy and solder joint geometry on Sn grain morphology in Pb free solder joints were examined. SnAgCu solder joints were examined for...free solder interconnects”, Sci. Technol. Weld . Join. 13, 732 (2008). [3.25] Terashima, S., Takahama, K., Nozaki, M., and Tanaka, M. Recrystallization
Reconfirmation of frit 803 based on the January 2016 sludge batch 9 reprojection

Energy Technology Data Exchange (ETDEWEB)

Johnson, F. [Savannah River Site (SRS), Aiken, SC (United States). Savannah River National Lab. (SRNL); Edwards, T. [Savannah River Site (SRS), Aiken, SC (United States). Savannah River National Lab. (SRNL)

2016-02-10

On January 11, 2016, Savannah River Remediation (SRR) provided the Savannah River National Laboratory (SRNL) with a Sludge Batch 9 (SB9) reprojection that was developed from the analyzed composition of a Tank 51 sample. This sample was collected after field washing had been completed in Tank 51 to support the alternate reductant task. Based on this reprojection, Frit 803 is still a viable option for the processing of SB9 under sludge-only operations and coupled (Actinide Removal Process (ARP) product with and without monosodium titanate (MST)) operations. The maximum projected volumes of ARP product that can be transferred from the Precipitate Reactor Feed Tank (PRFT) per Sludge Receipt and Adjustment Tank (SRAT) batch and the resulting Na₂O concentrations in the SRAT for coupled operations were determined. The Na₂O concentrations in the SRAT resulting from the maximum projected ARP product transfer volumes are consistent with those from the previous assessments that were based on the August 2015 projections. Regardless of the presence or absence of MST in the ARP product, the contribution of Na₂O to the resulting glass will be similar at the same waste loading (WL). These projected volumes of ARP product are not anticipated to be an issue for SB9. The actual transfer volumes from the PRFT to the SRAT are determined based upon the analyzed Na₂O concentrations in the PRFT samples, which has resulted in larger transfer volumes than those allowed by the projections for Sludge Batch 8 (SB8). An operating window of 32-40% WL around the nominal WL of 36% is achievable for both sludge-only and coupled operations; however, each of the glass systems studied does become limited by waste form affecting constraints (durability) at higher volumes of ARP product and WLs of 41-42%.
Production of muscovite-feldspathic glass composite: scanning electron microscopy and X-ray diffraction analysis; Producao de composito moscovita-vidro feldspatico: microscopia eletronica de varredura e analise de difracao de raios X

Energy Technology Data Exchange (ETDEWEB)

Costa, F.P.F.; Ogasawara, T.; Santos, S.F. [Universidade Federal do Rio de Janeiro (PEMM/COPPE/UFRJ), RJ (Brazil). Coordenacao dos Programas de Pos-graduacao em Engenharia. Programa de Engenharia Metalurgica e de Materiais; Franca, S.C.A.; Barbato, C.N [Centro de Tecnologia Mineral(CETEM/MCT), Rio de Janeiro, RJ (Brazil)

2009-07-01

The objective of this work was to find the sintering conditions for the feldspathic glass + muscovite mixture to produce a dense composite block for manufacturing dental prosthesis by using CAD-CAM. Each 20g of the glass-frit had : 15.55g of Armil-feldspar; 0.53g of Al{sub 2}O{sub 3}; 1.56g of Na{sub 2}CO{sub 3}; 0.5g of borax; 1.74g of K{sub 2}CO{sub 3}; 0.13g of CeO{sub 2}. Frit's powder finer than 350 Tyler mesh was mixed with 0 wt%, 10 wt%, 20 wt% and 100 wt% of muscovite pressed cylinders (5600 pounds force) 16mm in diameter and sintered under vacuum Vacumat (VITA) furnace at 850 deg C, 900 deg C, 950 deg C, 1000 deg C, 1050 deg C, 1100 deg C and 1150 deg C. X-ray diffraction analysis and scanning electron microscopy were carried out. The necessary temperature for high densification depended on the composition of the mixture: 850 deg C (for pure frit); 1050 deg C (for 10 wt% mica) and 1150 deg C (for 20 wt% mica); pure mica degraded during sintering. (author)
Characteristics of solder joints under fatigue loads using piezomechanical actuation

Science.gov (United States)

Shim, Dong-Jin; Spearing, S. Mark

2003-07-01

Crack initiation and growth characteristics of solder joints under fatigue loads are investigated using piezomechanical actuation. Cracks in solder joints, which can cause failure in microelectronics components, are induced via piezoelectricity in piezo-ceramic bonded joints. Lead-zirconate-titanate ceramic plates and eutectic Sn-Pb solder bonded in a double-lap shear configuration are used in the investigation. Electric field across each piezo-ceramic plate is applied such that shear stresses/strains are induced in the solder joints. The experiments show that cracks initiate in the solder joints around defects such as voids and grow in length until they coalesce with other cracks from adjacent voids. These observations are compared with the similar thermal cycling tests from the literature to show feasibility and validity of the current method in investigating the fatigue characteristics of solder joints. In some specimens, cracks in the piezo-ceramic plates are observed, and failure in the specimens generally occurred due to piezo-ceramic plate fracture. The issues encountered in implementing this methodology such as low actuation and high processing temperatures are further discussed.
Effect of Solder Flux Residues on Corrosion of Electronics

DEFF Research Database (Denmark)

Hansen, Kirsten Stentoft; Jellesen, Morten Stendahl; Møller, Per

2009-01-01

Flux from ‘No Clean’ solder processes can cause reliability problems in the field due to aggressive residues, which may be electrical conducting or corrosive in humid environments. The solder temperature during a wave solder process is of great importance to the amount of residues left on a PCBA...... testing and use in the field, consequences and recommendations are given. Failures, caused by harsh[1] customer environments, are not covered in this paper....
Influence of solder joint length to the mechanical aspect during the thermal stress analysis

Science.gov (United States)

Tan, J. S.; Khor, C. Y.; Rahim, Wan Mohd Faizal Wan Abd; Ishak, Muhammad Ikman; Rosli, M. U.; Jamalludin, Mohd Riduan; Zakaria, M. S.; Nawi, M. A. M.; Aziz, M. S. Abdul; Ani, F. Che

2017-09-01

Solder joint is an important interconnector in surface mount technology (SMT) assembly process. The real time stress, strain and displacement of the solder joint is difficult to observe and assess the experiment. To tackle these problems, simulation analysis was employed to study the von Mises stress, strain and displacement in the thermal stress analysis by using Finite element based software. In this study, a model of leadless electronic package was considered. The thermal stress analysis was performed to investigate the effect of the solder length to those mechanical aspects. The simulation results revealed that solder length gives significant effect to the maximum von Mises stress to the solder joint. Besides, changes in solder length also influence the displacement of the solder joint in the thermal environment. The increment of the solder length significantly reduces the von Mises stress and strain on the solder joint. Thus, the understanding of the physical parameter for solder joint is important for engineer prior to designing the solder joint of the electronic component.
Quality Analysis of Welded and Soldered Joints of Cu-Nb Microcomposite Wires

Directory of Open Access Journals (Sweden)

Nikolaj VIŠNIAKOV

2011-03-01

Full Text Available Quality analysis of welded and soldered joints of Cu-Nb microcomposite wires has been performed. Quality and mechanical characteristics of joints as ultimate tensile stress limit and elongation at break were measured with an universal testing machine and controlled visually using an optical microscope. Two wires joints were soldered with silver and copper solders and put into steel and copper sleeve respectively. Another two wires joints were soldered with silver solder and welded without any reinforcement. Joints soldered with the silver solder and steel sleeve have demonstrated the best mechanical characteristics: ultimate tensile stress limit of 650 MPa and elongation at break of 0.85 %. Joints soldered with the copper sleeve have no advantages comparing with the soldered butt joint. Ultimate tensile stress limit and elongation at break were in 300 MPa - 350 MPa and in 0.35 % - 0.45 % ranges respectively. Two welded joints had ultimate tensile stress limit of 470 MPa and elongation at break of 0.71 %. In all joints the microstructure of Nb filaments was destroyed and mechanical properties have been specified by mechanical strength of copper and sleeve materials only.http://dx.doi.org/10.5755/j01.ms.17.1.242
Development of a soft-soldering system for aluminum

Science.gov (United States)

Falke, W. L.; Lee, A. Y.; Neumeier, L. A.

1983-03-01

The method employs application of a thin nickel copper alloy coating to the substrate, which enables the tin lead solders to wet readily and spread over the areas to be joined. The aluminum substrate is mechanically or chemically cleaned to facilitate bonding to a minute layer of zinc that is subsequently applied, with an electroless zincate solution. The nickel copper alloy (30 to 70 pct Ni) coating is then applied electrolytically over the zinc, using immersion cell or brush coating techniques. Development of acetate electrolytes has permitted deposition of the proper alloys coatings. The coated areas can then be readily joined with conventional tin lead solders and fluxs. The joints so formed are ductile, strong, and relatively corrosion resistant, and exhibit strengths equivalent to those formed on copper and brass when the same solders and fluxes are used. The method has also been employed to soft solder magnesium alloys.
Properties and Microstructures of Sn-Bi-X Lead-Free Solders

Directory of Open Access Journals (Sweden)

Fan Yang

2016-01-01

Full Text Available The Sn-Bi base lead-free solders are proposed as one of the most popular alloys due to the low melting temperature (eutectic point: 139°C and low cost. However, they are not widely used because of the lower wettability, fatigue resistance, and elongation compared to traditional Sn-Pb solders. So the alloying is considered as an effective way to improve the properties of Sn-Bi solders with the addition of elements (Al, Cu, Zn, Ga, Ag, In, Sb, and rare earth and nanoparticles. In this paper, the development of Sn-Bi lead-free solders bearing elements and nanoparticles was reviewed. The variation of wettability, melting characteristic, electromigration, mechanical properties, microstructures, intermetallic compounds reaction, and creep behaviors was analyzed systematically, which can provide a reference for investigation of Sn-Bi base solders.
Physical properties of lead free solders in liquid and solid state

Energy Technology Data Exchange (ETDEWEB)

Mhiaoui, Souad

2007-04-17

The European legislation prohibits the use of lead containing solders in Europe. However, lead free solders have a higher melting point (typical 20%) and their mechanical characteristics are worse. Additional problems are aging and adhesion of the solder on the electronic circuits. Thus, research activities must focus on the optimization of the properties of Sn-Ag-Cu based lead free solders chosen by the industry. Two main objectives are treated in this work. In the center of the first one is the study of curious hysteresis effects of metallic cadmium-antimony alloys after thermal cycles by measuring electronic transport phenomena (thermoelectric power and electrical resistivity). The second objective, within the framework of ''cotutelle'' between the universities of Metz and of Chemnitz and supported by COST531, is to study more specifically lead free solders. A welding must well conduct electricity and well conduct and dissipate heat. In Metz, we determined the electrical conductivity, the thermoelectric power and the thermal conductivity of various lead free solders (Sn-Ag-Cu, Sn-Cu, Sn-Ag, Sn-Sb) as well in the liquid as well in the solid state. The results have been compared to classical lead-tin (Pb-Sn) solders. In Chemnitz we measured the surface tension, the interfacial tension and the density of lead free solders. We also measured the viscosity of these solders without and with additives, in particular nickel. These properties were related to the industrial problems of wettability and spreadability. Lastly, we solidified alloys under various conditions. We observed undercooling. We developed a technique of mixture of nanocrystalline powder with lead free solders ''to sow'' the liquid bath in order to obtain ''different'' solids which were examined using optical and electron microscopy. (orig.)
Interfacial Reaction of Sn-Ag-Cu Lead-Free Solder Alloy on Cu: A Review

Directory of Open Access Journals (Sweden)

Liu Mei Lee

2013-01-01

Full Text Available This paper reviews the function and importance of Sn-Ag-Cu solder alloys in electronics industry and the interfacial reaction of Sn-Ag-Cu/Cu solder joint at various solder forms and solder reflow conditions. The Sn-Ag-Cu solder alloys are examined in bulk and in thin film. It then examines the effect of soldering conditions to the formation of intermetallic compounds such as Cu substrate selection, structural phases, morphology evolution, the growth kinetics, temperature and time is also discussed. Sn-Ag-Cu lead-free solder alloys are the most promising candidate for the replacement of Sn-Pb solders in modern microelectronic technology. Sn-Ag-Cu solders could possibly be considered and adapted in miniaturization technologies. Therefore, this paper should be of great interest to a large selection of electronics interconnect materials, reliability, processes, and assembly community.
Failure Mechanisms of SAC/Fe-Ni Solder Joints During Thermal Cycling

Science.gov (United States)

Gao, Li-Yin; Liu, Zhi-Quan; Li, Cai-Fu

2017-08-01

Thermal cycling tests have been conducted on Sn-Ag-Cu/Fe- xNi ( x = 73 wt.% or 45 wt.%) and Sn-Ag-Cu/Cu solder joints according to the Joint Electron Device Engineering Council industrial standard to study their interfacial reliability under thermal stress. The interfacial intermetallic compounds formed for solder joints on Cu, Fe-73Ni, and Fe-45Ni were 4.5 μm, 1.7 μm, and 1.4 μm thick, respectively, after 3000 cycles, demonstrating excellent diffusion barrier effect of Fe-Ni under bump metallization (UBM). Also, two deformation modes, viz. solder extrusion and fatigue crack formation, were observed by scanning electron microscopy and three-dimensional x-ray microscopy. Solder extrusion dominated for solder joints on Cu, while fatigue cracks dominated for solder joints on Fe-45Ni and both modes were detected for those on Fe-73Ni. Solder joints on Fe-Ni presented inferior reliability during thermal cycling compared with those on Cu, with characteristic lifetime of 3441 h, 3190 h, and 1247 h for Cu, Fe-73Ni, and Fe-45Ni UBM, respectively. This degradation of the interfacial reliability for solder joints on Fe-Ni is attributed to the mismatch in coefficient of thermal expansion (CTE) at interconnection level. The CTE mismatch at microstructure level was also analyzed by electron backscatter diffraction for clearer identification of recrystallization-related deformation mechanisms.
Thermomechanical Behavior of Monolithic SN-AG-CU Solder and Copper Fiber Reinforced Solders

National Research Council Canada - National Science Library

Reuse, Rolando

2005-01-01

.... The thermomechanical cycling in the solder causes numerous reliability challenges, mostly because of the mismatch of the coefficient of thermal expansion between the silicon chip and the substrate...
Tensile strength of two soldered alloys (Minalux and Verabond2

Directory of Open Access Journals (Sweden)

Mir Mohammad Rezaee S

2002-07-01

Full Text Available Recently. Minalux alloy, a base metal free from Be, has been presented on the market while no special soldering has been recommended for it. On the other hand, based on the manufacturer's claim, this alloy is similar to Verabond2. The aim of this study was to investigate the tensile strength of Minalux and Verabond2, soldered by Verasolder. Twelve standard dambble shape samples, with the length of 18 mm and the diameter of 3mm, were prepared from each alloy. Six samples of each alloy were divided into two pieces with carboradom disk. Soldering gap distance was 0.3mm, measured by a special jig and they were soldered by Verasolder alloy. Six other samples, of both Iranian and foreign unsoldered alloys were considered as control group. Then samples were examined under tensile force and their tensile strength was recorded. Two- way variance analysis showed that the tensile strength of Minalux alloy and Verabond2 were not statistically significant (Verasoler 686, Minalux 723, but after soldering, such difference became significant (Minalux 308, Verabond2 432. Verabond2 showed higher tensile strength after soldering.
Effects of alpha radiation on hardness and toughness of the borosilicate glass applied to radioactive wastes immobilization

International Nuclear Information System (INIS)

Prado, Miguel Oscar; Bernasconi, Norma B. Messi de; Bevilacqua, Arturo Miguel; Arribere, Maria Angelica; Heredia, Arturo D.; Sanfilippo, Miguel

1999-01-01

Borosilicate german glass SG7 samples, obtained by frit sintering, were irradiated with different fluences of thermal neutrons in the nucleus of a nuclear reactor. The nuclear reaction 10 B(n,α) 7 Li, where the 10 B isotope is one of the natural glass components, was used to generate alpha particles throughout the glass volume. The maximum alpha disintegration per unit volume achieved was equivalent to that accumulated in a borosilicate glass with nuclear wastes after 3.8 million years. Through Vickers indentations values for microhardness, stress for 50% fracture probability (Weibull statistics) and estimation of the toughness were obtained as a function of alpha radiation dose. Two counterbalanced effects were found: that due to the disorder created by the alpha particles in the glass and that due to the annealing during irradiation (temperature below 240 deg C). Considering the alpha radiation effect, glasses tend decrease Vickers hardness, and to increase thr 50% fracture probability stress with the dose increase. (author)
New cementitious system: The case of glass frit

Science.gov (United States)

Fares, Galal

Canada ranks as the world's third largest aluminium producer, and more than 80% of its aluminum industry is concentrated in Quebec. However, the spent pot-liner waste produced by the aluminium smelters accumulates with time into a considerable amount threatening the Canadian environment, especially that of Quebec. A new-engineered material, known as glass fit (GF) has been developed through the chemical treatment of such waste. GF shows potential hydraulic and pozzolanic properties. GF has been studied as a binder itself and as a supplementary cementitious material (SCM). The activation of industrial by-products into clinkerless binders is a novel trend that has attracted the attention of many researchers. The activation of GF into binder to produce paste, mortar and concrete was the first aim of this study. Potential activation of GF using different types and combinations of inorganic activators and temperatures of activation was successfully achieved and high strength concretes were obtained. Moreover, mortars with high compressive strength were obtained with well-formulated activators at ambient temperature. On the other hand, the utilization of industrial by-products as a partial replacement for cement in concrete is a widespread practice. As GF contains a high concentration of sodium in its structure, there is a concern as to the effect of sodium content on the development of alkali-silica reaction (ASR) expansion of concrete. Therefore, this study also aimed to investigate the effect of GF sodium content in the enhancement of ASR expansion and to find new synergistic mixtures that can effectively mitigate ASR expansion in the long term. We observed that ASR expansion decreases with the replacement level of GF. Different synergistic diagrams containing known SCM (silica fume, fly ash, and slag) were achieved from which different effective mixtures can effectively alleviate ASR expansion. In conclusion, the use of GF in the manufacture of concrete has great
Creep deformation behavior in eutectic Sn-Ag solder joints using a novel mapping technique

Energy Technology Data Exchange (ETDEWEB)

Lucas, J.P.; Guo, F.; McDougall, J.; Bieler, T.R.; Subramanian, K.N.; Park, J.K.

1999-11-01

Creep deformation behavior was measured for 60--100 {micro}m thick solder joints. The solder joints investigated consisted of: (1) non-composite solder joints made with eutectic Sn-Ag solder, and (2) composite solder joints with eutectic Sn-Ag solder containing 20 vol.%, 5 {micro}m diameter in-situ Cu{sub 6}Sn{sub 5} intermetallic reinforcements. All creep testing in this study was carried out at room temperature. Qualitative and quantitative assessment of creep deformation was characterized on the solder joints. Creep deformation was analyzed using a novel mapping technique where a geometrical-regular line pattern was etched over the entire solder joint using excimer laser ablation. During creep, the laser-ablation (LA) pattern becomes distorted due to deformation in the solder joint. By imaging the distortion of laser-ablation patterns using the SEM, actual deformation mapping for the entire solder joint is revealed. The technique involves sequential optical/digital imaging of the deformation versus time history during creep. By tracing and recording the deformation of the LA patterns on the solder over intervals of time, local creep data are obtained in many locations in the joint. This analysis enables global and localized creep shear strains and strain rate to be determined.
Assessment of potential solder candidates for high temperature applications

DEFF Research Database (Denmark)

pressure to eliminate lead containing materials despite the fact that materials for high Pb containing alloys are currently not affected by any legislations. A tentative assessment was carried out to determine the potential solder candidates for high temperature applications based on the solidification...... criterion, phases predicted in the bulk solder and the thermodynamic stability of chlorides. These promising solder candidates were precisely produced using the hot stage microscope and its respective anodic and cathodic polarization curves were investigated using a micro-electrochemical set up...

Nano-soldering of magnetically aligned three-dimensional nanowire networks

International Nuclear Information System (INIS)

Gao Fan; Gu Zhiyong

2010-01-01

It is extremely challenging to fabricate 3D integrated nanostructures and hybrid nanoelectronic devices. In this paper, we report a simple and efficient method to simultaneously assemble and solder nanowires into ordered 3D and electrically conductive nanowire networks. Nano-solders such as tin were fabricated onto both ends of multi-segmented nanowires by a template-assisted electrodeposition method. These nanowires were then self-assembled and soldered into large-scale 3D network structures by magnetic field assisted assembly in a liquid medium with a high boiling point. The formation of junctions/interconnects between the nanowires and the scale of the assembly were dependent on the solder reflow temperature and the strength of the magnetic field. The size of the assembled nanowire networks ranged from tens of microns to millimeters. The electrical characteristics of the 3D nanowire networks were measured by regular current-voltage (I-V) measurements using a probe station with micropositioners. Nano-solders, when combined with assembling techniques, can be used to efficiently connect and join nanowires with low contact resistance, which are very well suited for sensor integration as well as nanoelectronic device fabrication.
Features of Pd-Ni-Fe solder system for vacuum brazing of low alloy steels

International Nuclear Information System (INIS)

Radzievskij, V.N.; Kurochko, R.S.; Lotsmanov, S.N.; Rymar', V.I.

1975-01-01

The brazing solder of the Pd-Ni-Fe alloyed with copper and lithium, in order to decrease the melting point and provide for a better spreading, when soldered in vacuum ensures a uniform strength of soldered joints with the base metal of low-alloyed steels of 34KHNIM-type. The properties of low-alloyed steel joints brazed with the Pd-Ni-Fe-system solder little depend on the changes in the soldering parameters. The soldered joint keeps a homogeneous structure after all the stages of heat treatment (annealing, quenching and tempering)
A Hodge dual for soldered bundles

International Nuclear Information System (INIS)

Lucas, Tiago Gribl; Pereira, J G

2009-01-01

In order to account for all possible contractions allowed by the presence of the solder form, a generalized Hodge dual is defined for the case of soldered bundles. Although for curvature the generalized dual coincides with the usual one, for torsion it gives a completely new dual definition. Starting from the standard form of a gauge Lagrangian for the translation group, the generalized Hodge dual yields precisely the Lagrangian of the teleparallel equivalent of general relativity, and consequently also the Einstein-Hilbert Lagrangian of general relativity
Mechanochemically synthesized kalsilite based bioactive glass-ceramic composite for dental vaneering

Science.gov (United States)

Kumar, Pattem Hemanth; Singh, Vinay Kumar; Kumar, Pradeep

2017-08-01

Kalsilite glass-ceramic composites have been prepared by a mechanochemical synthesis process for dental veneering application. The aim of the present study is to prepare bioactive kalsilite composite material for application in tissue attachment and sealing of the marginal gap between fixed prosthesis and tooth. Mechanochemical synthesis is used for the preparation of microfine kalsilite glass-ceramic. Low temperature frit and bioglass have been prepared using the traditional quench method. Thermal, microstructural and bioactive properties of the composite material have been examined. The feasibility of the kalsilite to be coated on the base commercial opaque as well as the bioactive behavior of the coated specimen has been confirmed. This study indicates that the prepared kalsilite-based composites show similar structural, morphological and bioactive behavior to that of commercial VITA VMK95 Dentin 1M2.
Characterization of the microstructure of tin-silver lead free solder

Energy Technology Data Exchange (ETDEWEB)

Hurtony, Tamás, E-mail: hurtony@ett.bme.hu [Department of Electronics Technology, Budapest University of Technology and Economics, Egry József utca 18, Budapest, H-1111 (Hungary); Szakál, Alex; Almásy, László [Neutron Spectroscopy Department, Wigner Research Centre for Physics, Budapest (Hungary); Len, Adél [Neutron Spectroscopy Department, Wigner Research Centre for Physics, Budapest (Hungary); Faculty of Engineering and Information Technology, University of Pécs (Hungary); Kugler, Sándor [Department of Theoretical Physics, Budapest University of Technology and Economics (Hungary); Bonyár, Attila; Gordon, Péter [Department of Electronics Technology, Budapest University of Technology and Economics, Egry József utca 18, Budapest, H-1111 (Hungary)

2016-07-05

Reliability and lifetime are the two most relevant design considerations in the production of safety critical assemblies. For example in a modern automobile dozens of electronic assemblies are integrated in which thousands of solder joints are mounting the electronic components to the printed circuit boards. There exists no standardised and universal observation method for characterising the fine microstructure of such solder joints. Previously we have developed a new method for the quantitative characterization of lead-free solder alloys and in present study the validity of the proposed method is demonstrated. Microstructure of Sn-3.5Ag lead free solder alloy was investigated by electrochemical impedance spectroscopy. Solder samples were solidified with different cooling rates in order to induce differences in the microstructure. Microstructure of the ingots was revealed by selective electrochemical etching. Electrochemical impedance spectra (EIS) were measured before and after the selective etching process. The complex impedance spectra contain information about microstructure of the solder alloys. Comparison and modelling of two EIS spectra allowed obtaining a characteristic parameter of surface structure of the etched specimens. The EIS measurements were complemented with small angle neutron scattering measurements and scanning electron microscopy, in order to correlate the EIS parameter with the magnitude of the interface of the β-Sn and Ag{sub 3}Sn phases.
Dye-enhanced protein solders and patches in laser-assisted tissue welding.

Science.gov (United States)

Small, W; Heredia, N J; Maitland, D J; Da Silva, L B; Matthews, D L

1997-01-01

This study examines the use of dye-enhanced protein bonding agents in 805 nm diode laser-assisted tissue welding. A comparison of an albumin liquid solder and collagen solid-matrix patches used to repair arteriotomies in an in vitro porcine model is presented. Extrinsic bonding media in the form of solders and patches have been used to enhance the practice of laser tissue welding. Preferential absorption of the laser wavelength has been achieved by the incorporation of chromophores. Both the solder and the patch included indocyanine green dye (ICG) to absorb the 805 nm continuous-wave diode laser light used to perform the welds. Solder-mediated welds were divided into two groups (high power/short exposure and low power/long exposure), and the patches were divided into three thickness groups ranging from 0.1 to 1.3 mm. The power used to activate the patches was constant, but the exposure time was increased with patch thickness. Burst pressure results indicated that solder-mediated and patched welds yielded similar average burst strengths in most cases, but the patches provided a higher success rate (i.e., more often exceeded 150 mmHg) and were more consistent (i.e., smaller standard deviation) than the solder. The strongest welds were obtained using 1.0-1.3 mm thick patches, while the high power/short exposure solder group was the weakest. Though the solder and patches yielded similar acute weld strengths, the solid-matrix patches facilitated the welding process and provided consistently strong welds. The material properties of the extrinsic agents influenced their performance.
Drinking Water Contamination Due To Lead-based Solder

Science.gov (United States)

Garcia, N.; Bartelt, E.; Cuff, K. E.

2004-12-01

The presence of lead in drinking water creates many health hazards. Exposure to lead-contaminated water can affect the brain, the central nervous system, blood cells, and kidneys, causing such problems as mental retardation, kidney disease, heart disease, stroke, and death. One way in which lead can contaminate our water supply is through the use of lead solder to join pipes. Lead solder was widely used in the past because of its ease of application as well as its low cost. Lead contamination in residential areas has previously been found to be a particularly serious problem in first-draw samples, of water that has sat stagnant in pipes overnight. To investigate the time-dependence of drinking water lead contamination, we analyzed samples taken hourly of water exposed to lead solder. While our preliminary data was insufficient to show more than a rough correlation between time of exposure and lead concentration over short periods (1-3 hours), we were able to confirm that overnight exposure of water to lead-based solder results in the presence high levels of lead. We also investigated other, external factors that previous research has indicated contribute to increased concentrations of lead. Our analysis of samples of lead-exposed water at various pH and temperatures suggests that these factors can be equally significant in terms of their contribution to elevated lead concentration levels. In particular, water that is slightly corrosive appears to severely impact the solubility of lead. As this type of water is common in much of the Northeast United States, the presence of lead-based solder in residential areas there is especially problematic. Although lead-based solder has been banned since the 1980s, it remains a serious concern, and a practical solution still requires further research.
Formulation Efforts for Direct Vitrification of INEEL Blend Calcine Waste Simulate: Fiscal Year 2000

Energy Technology Data Exchange (ETDEWEB)

Crum, Jarrod V.; Vienna, John D.; Peeler, David K.; Reamer, I. A.

2001-03-30

This report documents the results of glass formulation efforts for Idaho National Engineering and Environmental Laboratory (INEEL) high level waste (HWL) calcine. Two waste compositions were used during testing. Testing started by using the Run 78 calcine composition and switched to simulated Blend calcine composition when it became available. The goal of the glass formulation efforts was to develop a frit composition that will accept higher waste loading that satisfies the glass processing and product acceptance constraints. 1. Melting temperature of 1125 ? 25?C 2. Viscosity between 2 and 10 Pa?s at the melting temperature 3. Liquidus temperature at least 100?C below the melting temperature 4. Normalized release of B, Li and Na each below 1 g/m2 (per ASTM C 1285-97) Glass formulation efforts tested several frit compositions with variable waste loadings of Run 78 calcine waste simulant. Frit 107 was selected as the primary candidate for processing since it met all process and performance criteria up to 45 mass% waste loading. When the simulated Blend calcine waste composition became available Frits 107 and 108 compositions were retested and again Frit 107 remained the primary candidate. However, both frits suffered a decrease in waste loading when switching from the Run 78 calcine to simulated Blend calcine waste composition. This was due to increase concentrations of both F and Al2O3 along with a decrease in CaO and Na2O in the simulate Blend calcine waste all of which have strong impacts on the glass properties that limit waste loading of this type of waste.
Horizon shells and BMS-like soldering transformations

Energy Technology Data Exchange (ETDEWEB)

Blau, Matthias [Albert Einstein Center for Fundamental Physics,Institute for Theoretical Physics, University of Bern,Sidlerstrasse 5, 3012 Bern (Switzerland); O’Loughlin, Martin [University of Nova Gorica,Vipavska 13, 5000 Nova Gorica (Slovenia)

2016-03-07

We revisit the theory of null shells in general relativity, with a particular emphasis on null shells placed at horizons of black holes. We study in detail the considerable freedom that is available in the case that one solders two metrics together across null hypersurfaces (such as Killing horizons) for which the induced metric is invariant under translations along the null generators. In this case the group of soldering transformations turns out to be infinite dimensional, and these solderings create non-trivial horizon shells containing both massless matter and impulsive gravitational wave components. We also rephrase this result in the language of Carrollian symmetry groups. To illustrate this phenomenon we discuss in detail the example of shells on the horizon of the Schwarzschild black hole (with equal interior and exterior mass), uncovering a rich classical structure at the horizon and deriving an explicit expression for the general horizon shell energy-momentum tensor. In the special case of BMS-like soldering supertranslations we find a conserved shell-energy that is strikingly similar to the standard expression for asymptotic BMS supertranslation charges, suggesting a direct relation between the physical properties of these horizon shells and the recently proposed BMS supertranslation hair of a black hole.
Effects of soldering methods on tensile strength of a gold-palladium metal ceramic alloy.

Science.gov (United States)

Ghadhanfari, Husain A; Khajah, Hasan M; Monaco, Edward A; Kim, Hyeongil

2014-10-01

The tensile strength obtained by conventional postceramic application soldering and laser postceramic welding may require more energy than microwave postceramic soldering, which could provide similar tensile strength values. The purpose of the study was to compare the tensile strength obtained by microwave postceramic soldering, conventional postceramic soldering, and laser postceramic welding. A gold-palladium metal ceramic alloy and gold-based solder were used in this study. Twenty-seven wax specimens were cast in gold-palladium noble metal and divided into 4 groups: laser welding with a specific postfiller noble metal, microwave soldering with a postceramic solder, conventional soldering with the same postceramic solder used in the microwave soldering group, and a nonsectioned control group. All the specimens were heat treated to simulate a normal porcelain sintering sequence. An Instron Universal Testing Machine was used to measure the tensile strength for the 4 groups. The means were analyzed statistically with 1-way ANOVA. The surface and fracture sites of the specimens were subjectively evaluated for fracture type and porosities by using a scanning electron microscope. The mean (standard deviation) ultimate tensile strength values were as follows: nonsectioned control 818 ±30 MPa, microwave 516 ±34 MPa, conventional 454 ±37 MPa, and laser weld 191 ±39 MPa. A 1-way ANOVA showed a significant difference in ultimate tensile strength among the groups (F3,23=334.5; Ptensile strength for gold and palladium noble metals than either conventional soldering or laser welding. Conventional soldering resulted in a higher tensile strength than laser welding. Under the experimental conditions described, either microwave or conventional postceramic soldering would appear to satisfy clinical requirements related to tensile strength. Copyright © 2014 Editorial Council for the Journal of Prosthetic Dentistry. Published by Elsevier Inc. All rights reserved.
Calibration and Measurement of the Viscosity of DWPF Start-Up Glass

International Nuclear Information System (INIS)

Schumacher, R.F.

2001-01-01

The Harrop, High-Temperature Viscometer has been in operation at the Savannah River Technology Center (SRTC) for several years and has proven itself to be reasonably accurate and repeatable. This is particularly notable when taking into consideration the small amount of glass required to make the viscosity determination. The volume of glass required is only 2.60 cc or about 6 to 7 grams of glass depending on the glass density. This may be compared to the more traditional viscosity determinations, which generally require between 100 to 1000 grams of glass. Before starting the present investigation, the unit was re-aligned and the furnace thermal gradients measured. The viscometer was again calibrated with available NIST Standard Reference Material glasses (717a and 710a) and a spindle constant equation was determined. Standard DWPF Waste Compliance Glasses (Purex, HM, and Batch 1) were used to provide additional verification for the determinations at low temperature. The Harrop, High-Temperature Viscometer was then used to determine the viscosity of three random samples of ground and blended DWPF, Black, Start -Up Frit, which were obtained from Pacific Northwest National Laboratory (PNNL). The glasses were in powder form and required melting prior to the viscosity determination. The results from this evaluation will be compared to ''Round Robin'' measurements from other DOE laboratories and a number of commercial laboratories
Soldering Characteristics and Mechanical Properties of Sn-1.0Ag-0.5Cu Solder with Minor Aluminum Addition

Directory of Open Access Journals (Sweden)

Yee Mei Leong

2016-06-01

Full Text Available Driven by the trends towards miniaturization in lead free electronic products, researchers are putting immense efforts to improve the properties and reliabilities of Sn based solders. Recently, much interest has been shown on low silver (Ag content solder SAC105 (Sn-1.0Ag-0.5Cu because of economic reasons and improvement of impact resistance as compared to SAC305 (Sn-3.0Ag-0.5Cu. The present work investigates the effect of minor aluminum (Al addition (0.1–0.5 wt.% to SAC105 on the interfacial structure between solder and copper substrate during reflow. The addition of minor Al promoted formation of small, equiaxed Cu-Al particle, which are identified as Cu3Al2. Cu3Al2 resided at the near surface/edges of the solder and exhibited higher hardness and modulus. Results show that the minor addition of Al does not alter the morphology of the interfacial intermetallic compounds, but they substantially suppress the growth of the interfacial Cu6Sn5 intermetallic compound (IMC after reflow. During isothermal aging, minor alloying Al has reduced the thickness of interfacial Cu6Sn5 IMC but has no significant effect on the thickness of Cu3Sn. It is suggested that of atoms of Al exert their influence by hindering the flow of reacting species at the interface.
Soldering Characteristics and Mechanical Properties of Sn-1.0Ag-0.5Cu Solder with Minor Aluminum Addition

Science.gov (United States)

Leong, Yee Mei; Haseeb, A.S.M.A.

2016-01-01

Driven by the trends towards miniaturization in lead free electronic products, researchers are putting immense efforts to improve the properties and reliabilities of Sn based solders. Recently, much interest has been shown on low silver (Ag) content solder SAC105 (Sn-1.0Ag-0.5Cu) because of economic reasons and improvement of impact resistance as compared to SAC305 (Sn-3.0Ag-0.5Cu. The present work investigates the effect of minor aluminum (Al) addition (0.1–0.5 wt.%) to SAC105 on the interfacial structure between solder and copper substrate during reflow. The addition of minor Al promoted formation of small, equiaxed Cu-Al particle, which are identified as Cu3Al2. Cu3Al2 resided at the near surface/edges of the solder and exhibited higher hardness and modulus. Results show that the minor addition of Al does not alter the morphology of the interfacial intermetallic compounds, but they substantially suppress the growth of the interfacial Cu6Sn5 intermetallic compound (IMC) after reflow. During isothermal aging, minor alloying Al has reduced the thickness of interfacial Cu6Sn5 IMC but has no significant effect on the thickness of Cu3Sn. It is suggested that of atoms of Al exert their influence by hindering the flow of reacting species at the interface. PMID:28773645
Effects of Fe2NiO4 nanoparticles addition into lead free Sn–3.0Ag–0.5Cu solder pastes on microstructure and mechanical properties after reflow soldering process

International Nuclear Information System (INIS)

Chellvarajoo, Srivalli; Abdullah, M.Z.; Samsudin, Z.

2015-01-01

Highlights: • Fe 2 NiO 4 nanoparticles added into SAC 305 by mechanical mixing to form nanocomposite solder paste. • Nanoparticles in the composite solder travels with flux to the outermost surface after reflow. • The intermetallics compound reduced with the addition of nanoparticles into solder paste. • The hardness increased with the addition of limited percentage of nanoparticles into SAC 305. - Abstract: This study investigates the effects of the addition of Fe 2 NiO 4 nanoparticles into a SAC-305 lead-free solder paste. Iron, nickel, and oxide nano-elements were mixed with Pb-free solder alloying elements to produce a new form of nanocomposite solder paste, which can be a promising material in electronic packaging. The SAC-305 was mechanically added with 0.5, 1.5, and 2.5 wt.% of Fe 2 NiO 4 nanoparticles. The migration of nanoparticles in the nanocomposite solder paste to the outermost surface was clarified using the copper ‘sandwich’ method, which was performed after the reflow soldering process. Varying amounts of nanoparticles in the SAC-305 affected the IMC thickness and mechanical properties of the nanocomposite solder paste. The IMC thickness was reduced by 29.15%, 42.37%, and 59.00% after adding 0.5, 1.5, and 2.5 wt.% of Fe 2 NiO 4 nanoparticles in the SAC-305, respectively. However, via nanoindentation method, the hardness of the nanocomposite solder was improved by 44.07% and 56.82% after adding 0.5 and 1.5 wt.% of Fe 2 NiO 4 nanoparticles, respectively. If the addition of Fe 2 NiO 4 nanoparticle exceeded 1.5 wt.%, the hardness increased infinitely
The metallurgical approach on the solder voids behaviour in surface mount devices

International Nuclear Information System (INIS)

Mohabattul Zaman Bukhari

1996-01-01

Solder voids are believed to cause poor heat dissiption in the Surface Mount devices and reduce the reliability of the devices at higher operating services. There are a lot of factors involved in creating voids such as gas/flux entrapment, wettability, outgasseous, air bubbles in the solder paste, inconsistency of solder coverage and improper metal scheme selection. This study was done to observe the behaviour of the solder voids in term of flux entrapmentt and wettability. It is believed that flux entrapment and wettability are verify this hypothesis. Two types of metal scheme were chosen which are Nickel (Ni) plated and Tin (Sn) plated heatsink. X-ray techniques such as Radiographic Inspection Analysis and EDAX were used to detect the minute solder voids. The solder voids observed on the heatsinks and Copper shims after the reflow process are believed to be a non contact voids that resulted from some portion of the surface not wetting properly
Damage behavior of SnAgCu/Cu solder joints subjected to thermomechanical cycling

International Nuclear Information System (INIS)

Xiao, H.; Li, X.Y.; Hu, Y.; Guo, F.; Shi, Y.W.

2013-01-01

Highlights: •A creep–fatigue damage model based on CDM was proposed. •Designed system includes load frame, strain measure device and damage test device. •Damage evolution of solder joints was a function of accumulated inelastic strain. •Damage of solder joints is an interaction between creep and low-cycle fatigue. -- Abstract: Thermomechanical fatigue damage is a progressive process of material degradation. The objective of this study was to investigate the damage behavior of SnAgCu/Cu solder joints under thermomechanical cycling. A damage model was proposed based on continuum damage mechanics (CDM). Based upon an analysis of displacements for flip-chip solder joints subjected to thermal cycling, a special bimetallic loading frame with single-solder joint samples was designed to simulate the service conditions of actual joints in electronic packages. The assembly, which allowed for strain measurements of an individual solder joint during temperature cycling, was used to investigate the impact of stress–strain cycling on the damage behavior of SnAgCu/Cu solder joints. The characteristic parameters of the damage model were determined through thermomechanical cycling and strain measurement tests. The damage variable D = 1 − R 0 /R was selected, and values for it were obtained using a four-probe method for the single-solder joint samples every dozen cycles during thermomechanical cycling tests to verify the model. The results showed that the predicted damage was in good agreement with the experimental results. The damage evolution law proposed here is a function of inelastic strain, and the results showed that the damage rate of SnAgCu/Cu solder joints increased as the range of the applied strain increased. In addition, the microstructure evolution of the solder joints was analyzed using scanning electron microscopy, which provided the microscopic explanation for the damage evolution law of SnAgCu/Cu solder joints
Damage behavior of SnAgCu/Cu solder joints subjected to thermomechanical cycling

Energy Technology Data Exchange (ETDEWEB)

Xiao, H., E-mail: xiaohui2013@yahoo.com.cn; Li, X.Y.; Hu, Y.; Guo, F.; Shi, Y.W.

2013-11-25

Highlights: •A creep–fatigue damage model based on CDM was proposed. •Designed system includes load frame, strain measure device and damage test device. •Damage evolution of solder joints was a function of accumulated inelastic strain. •Damage of solder joints is an interaction between creep and low-cycle fatigue. -- Abstract: Thermomechanical fatigue damage is a progressive process of material degradation. The objective of this study was to investigate the damage behavior of SnAgCu/Cu solder joints under thermomechanical cycling. A damage model was proposed based on continuum damage mechanics (CDM). Based upon an analysis of displacements for flip-chip solder joints subjected to thermal cycling, a special bimetallic loading frame with single-solder joint samples was designed to simulate the service conditions of actual joints in electronic packages. The assembly, which allowed for strain measurements of an individual solder joint during temperature cycling, was used to investigate the impact of stress–strain cycling on the damage behavior of SnAgCu/Cu solder joints. The characteristic parameters of the damage model were determined through thermomechanical cycling and strain measurement tests. The damage variable D = 1 − R{sub 0}/R was selected, and values for it were obtained using a four-probe method for the single-solder joint samples every dozen cycles during thermomechanical cycling tests to verify the model. The results showed that the predicted damage was in good agreement with the experimental results. The damage evolution law proposed here is a function of inelastic strain, and the results showed that the damage rate of SnAgCu/Cu solder joints increased as the range of the applied strain increased. In addition, the microstructure evolution of the solder joints was analyzed using scanning electron microscopy, which provided the microscopic explanation for the damage evolution law of SnAgCu/Cu solder joints.
Evaluation of low-residue soldering for military and commercial applications: A report from the Low-Residue Soldering Task Force

Energy Technology Data Exchange (ETDEWEB)

Iman, R.L.; Anderson, D.J. [Sandia National Labs., Albuquerque, NM (United States); Burress, R.V. [SEHO (United States)] [and others

1995-06-01

The LRSTF combined the efforts of industry, military, and government to evaluate low-residue soldering processes for military and commercial applications. These processes were selected for evaluation because they provide a means for the military to support the presidential mandate while producing reliable hardware at a lower cost. This report presents the complete details and results of a testing program conducted by the LRSTF to evaluate low-residue soldering for printed wiring assemblies. A previous informal document provided details of the test plan used in this evaluation. Many of the details of that test plan are contained in this report. The test data are too massive to include in this report, however, these data are available on disk as Excel spreadsheets upon request. The main purpose of low-residue soldering is to eliminate waste streams during the manufacturing process.
Technical Status Report: Preliminary Glass Formulation Report for INEEL HAW. Revision 1

International Nuclear Information System (INIS)

Peeler, D.; Reamer, I.; Vienna, J.; Crum, J.A.

1998-03-01

Preliminary glass formulation work has been initiated at Pacific Northwest National Laboratory (PNNL) and the Savannah River Technology Center (SRTC) to support immobilization efforts of Idaho National Engineering and Environmental Laboratory (INEEL) high activity waste (HAW). Based on current pretreatment flow sheet assumptions, several glasses were fabricated and tested using an average 'All Blend' waste stream composition which is dominated by the presence of ZrO 2 (i.e., approximately 80 wt percent). The results of this initial work show that immobilization via vitrification is a viable option for a specific INEEL HAW waste stream. Waste loadings of at least 19 wt percent can be achieved for the 'All Blend' stream while maintaining targeted processing and product performance criteria. This waste loading translates into a ZrO 2 content in excess of 15 wt percent in the final glass waste form. Frits developed for this work are based in the alkali borosilicate system. Although the results indicate that vitrification can be used to immobilize the 'All Blend' waste stream, the glass compositions are by no means optimized
Laser Soldering of Rat Skin Using a Controlled Feedback System

Directory of Open Access Journals (Sweden)

Mohammad Sadegh Nourbakhsh

2009-03-01

Full Text Available Introduction: Laser tissue soldering using albumin and indocyanine green dye (ICG is an effective technique utilized in various surgical procedures. The purpose of this study was to perform laser soldering of rat skin under a feedback control system and compare the results with those obtained using standard sutures. Material and Methods: Skin incisions were made over eight rats’ dorsa, which were subsequently closed using different wound closure interventions in two groups: (a using a temperature controlled infrared detector or (b by suture. Tensile strengths were measured at 2, 5, 7 and 10 days post-incision. Histological examination was performed at the time of sacrifice. Results: Tensile strength results showed that during the initial days following the incisions, the tensile strengths of the sutured samples were greater than the laser samples. However, 10 days after the incisions, the tensile strengths of the laser soldered incisions were higher than the sutured cuts. Histopathological examination showed a preferred wound healing response in the soldered skin compared with the control samples. The healing indices of the laser soldered repairs (426 were significantly better than the control samples (340.5. Conclusion: Tissue feedback control of temperature and optical changes in laser soldering of skin leads to a higher tensile strength and better histological results and hence this method may be considered as an alternative to standard suturing.

Temperature-controlled laser-soldering system and its clinical application for bonding skin incisions

Science.gov (United States)

Simhon, David; Gabay, Ilan; Shpolyansky, Gregory; Vasilyev, Tamar; Nur, Israel; Meidler, Roberto; Hatoum, Ossama Abu; Katzir, Abraham; Hashmonai, Moshe; Kopelman, Doron

2015-12-01

Laser tissue soldering is a method of repairing incisions. It involves the application of a biological solder to the approximated edges of the incision and heating it with a laser beam. A pilot clinical study was carried out on 10 patients who underwent laparoscopic cholecystectomy. Of the four abdominal incisions in each patient, two were sutured and two were laser soldered. Cicatrization, esthetical appearance, degree of pain, and pruritus in the incisions were examined on postoperative days 1, 7, and 30. The soldered wounds were watertight and healed well, with no discharge from these wounds or infection. The total closure time was equal in both methods, but the net soldering time was much shorter than suturing. There was no difference between the two types of wound closure with respect to the pain and pruritus on a follow-up of one month. Esthetically, the soldered incisions were estimated as good as the sutured ones. The present study confirmed that temperature-controlled laser soldering of human skin incisions is clinically feasible, and the results obtained were at least equivalent to those of standard suturing.
Corrosive microenvironments at lead solder surfaces arising from galvanic corrosion with copper pipe.

Science.gov (United States)

Nguyen, Caroline K; Stone, Kendall R; Dudi, Abhijeet; Edwards, Marc A

2010-09-15

As stagnant water contacts copper pipe and lead solder (simulated soldered joints), a corrosion cell is formed between the metals in solder (Pb, Sn) and the copper. If the resulting galvanic current exceeds about 2 μA/cm(2), a highly corrosive microenvironment can form at the solder surface, with pH chloride concentrations at least 11 times higher than bulk water levels. Waters with relatively high chloride tend to sustain high galvanic currents, preventing passivation of the solder surface, and contributing to lead contamination of potable water supplies. The total mass of lead corroded was consistent with predictions based on the galvanic current, and lead leaching to water was correlated with galvanic current. If the concentration of sulfate in the water increased relative to chloride, galvanic currents and associated lead contamination could be greatly reduced, and solder surfaces were readily passivated.
Effects of Metallic Nanoparticles on Interfacial Intermetallic Compounds in Tin-Based Solders for Microelectronic Packaging

Science.gov (United States)

Haseeb, A. S. M. A.; Arafat, M. M.; Tay, S. L.; Leong, Y. M.

2017-10-01

Tin (Sn)-based solders have established themselves as the main alternative to the traditional lead (Pb)-based solders in many applications. However, the reliability of the Sn-based solders continues to be a concern. In order to make Sn-based solders microstructurally more stable and hence more reliable, researchers are showing great interest in investigating the effects of the incorporation of different nanoparticles into them. This paper gives an overview of the influence of metallic nanoparticles on the characteristics of interfacial intermetallic compounds (IMCs) in Sn-based solder joints on copper substrates during reflow and thermal aging. Nanocomposite solders were prepared by mechanically blending nanoparticles of nickel (Ni), cobalt (Co), zinc (Zn), molybdenum (Mo), manganese (Mn) and titanium (Ti) with Sn-3.8Ag-0.7Cu and Sn-3.5Ag solder pastes. The composite solders were then reflowed and their wetting characteristics and interfacial microstructural evolution were investigated. Through the paste mixing route, Ni, Co, Zn and Mo nanoparticles alter the morphology and thickness of the IMCs in beneficial ways for the performance of solder joints. The thickness of Cu3Sn IMC is decreased with the addition of Ni, Co and Zn nanoparticles. The thickness of total IMC layer is decreased with the addition of Zn and Mo nanoparticles in the solder. The metallic nanoparticles can be divided into two groups. Ni, Co, and Zn nanoparticles undergo reactive dissolution during solder reflow, causing in situ alloying and therefore offering an alternative route of alloy additions to solders. Mo nanoparticles remain intact during reflow and impart their influence as discrete particles. Mechanisms of interactions between different types of metallic nanoparticles and solder are discussed.
Fundamentals of lead-free solder interconnect technology from microstructures to reliability

CERN Document Server

Lee, Tae-Kyu; Kim, Choong-Un; Ma, Hongtao

2015-01-01

This unique book provides an up-to-date overview of the fundamental concepts behind lead-free solder and interconnection technology. Readers will find a description of the rapidly increasing presence of electronic systems in all aspects of modern life as well as the increasing need for predictable reliability in electronic systems. The physical and mechanical properties of lead-free solders are examined in detail, and building on fundamental science, the mechanisms responsible for damage and failure evolution, which affect reliability of lead-free solder joints are identified based on microstructure evolution. The continuing miniaturization of electronic systems will increase the demand on the performance of solder joints, which will require new alloy and processing strategies as well as interconnection design strategies. This book provides a foundation on which improved performance and new design approaches can be based. In summary, this book: Provides an up-to-date overview on lead-free soldering tech...
Low sintering temperature glass waste forms for sequestering radioactive iodine

Science.gov (United States)

Nenoff, Tina M.; Krumhansl, James L.; Garino, Terry J.; Ockwig, Nathan W.

2012-09-11

Materials and methods of making low-sintering-temperature glass waste forms that sequester radioactive iodine in a strong and durable structure. First, the iodine is captured by an adsorbant, which forms an iodine-loaded material, e.g., AgI, AgI-zeolite, AgI-mordenite, Ag-silica aerogel, ZnI.sub.2, CuI, or Bi.sub.5O.sub.7I. Next, particles of the iodine-loaded material are mixed with powdered frits of low-sintering-temperature glasses (comprising various oxides of Si, B, Bi, Pb, and Zn), and then sintered at a relatively low temperature, ranging from 425.degree. C. to 550.degree. C. The sintering converts the mixed powders into a solid block of a glassy waste form, having low iodine leaching rates. The vitrified glassy waste form can contain as much as 60 wt % AgI. A preferred glass, having a sintering temperature of 500.degree. C. (below the silver iodide sublimation temperature of 500.degree. C.) was identified that contains oxides of boron, bismuth, and zinc, while containing essentially no lead or silicon.
Effect of phosphorus element on the comprehensive properties of Sn-Cu lead-free solder

International Nuclear Information System (INIS)

Li Guangdong; Shi Yaowu; Hao Hu; Xia Zhidong; Lei Yongping; Guo Fu

2010-01-01

In the present work, the effect of phosphorus on the creep fatigue properties of Sn-Cu eutectic lead-free solder was carried out. The experimental results show that the melting temperature was almost not changed with adding small amount of P element. However, the addition of trace P element led to the decrease in the property of creep fatigue. The fractography analysis by a scanning electron microscopy (SEM) shows that ductile fracture was the dominant failure behavior in the process of creep fatigue test of Sn0.7Cu and Sn0.7Cu0.005P specimens. It should be pointed out that there is significant difference in the fractographs between the joints of Sn0.7Cu solder and Sn0.7Cu0.005P solder. In the fractograph of Sn0.7Cu solder joint, the microstructure is prolonged along testing direction, and the dimples were more than the fractograph of Sn0.7Cu0.005P solder joint. In addition, the voids could be found on the Sn0.7Cu0.005P solder joint, and trace P addition may increase the rate of forming void of Sn0.7Cu solder joint. The voids can potentially lead to crack initiation or propagation sites in the solder joint. As a result, the creep fatigue of solder joint containing P such as Sn0.7Cu0.005P offers worse property compared to Sn0.7Cu solder joint.
Effect of phosphorus element on the comprehensive properties of Sn-Cu lead-free solder

Energy Technology Data Exchange (ETDEWEB)

Li Guangdong, E-mail: liguangdong@emails.bjut.edu.c [College of Materials Science and Engineering, Beijing University of Technology, 100 Ping Le Yuan, Chaoyang District, Beijing 100124 (China); Shi Yaowu; Hao Hu; Xia Zhidong; Lei Yongping; Guo Fu [College of Materials Science and Engineering, Beijing University of Technology, 100 Ping Le Yuan, Chaoyang District, Beijing 100124 (China)

2010-02-18

In the present work, the effect of phosphorus on the creep fatigue properties of Sn-Cu eutectic lead-free solder was carried out. The experimental results show that the melting temperature was almost not changed with adding small amount of P element. However, the addition of trace P element led to the decrease in the property of creep fatigue. The fractography analysis by a scanning electron microscopy (SEM) shows that ductile fracture was the dominant failure behavior in the process of creep fatigue test of Sn0.7Cu and Sn0.7Cu0.005P specimens. It should be pointed out that there is significant difference in the fractographs between the joints of Sn0.7Cu solder and Sn0.7Cu0.005P solder. In the fractograph of Sn0.7Cu solder joint, the microstructure is prolonged along testing direction, and the dimples were more than the fractograph of Sn0.7Cu0.005P solder joint. In addition, the voids could be found on the Sn0.7Cu0.005P solder joint, and trace P addition may increase the rate of forming void of Sn0.7Cu solder joint. The voids can potentially lead to crack initiation or propagation sites in the solder joint. As a result, the creep fatigue of solder joint containing P such as Sn0.7Cu0.005P offers worse property compared to Sn0.7Cu solder joint.
Characteristics of diffusion zone in changing glass-metal composite processing conditions

Science.gov (United States)

Lyubimova, O. N.; Morkovin, A. V.; Andreev, V. V.

2018-03-01

The influence of manufacturing technology on the characteristics of the glass and steel contact zone in manufacturing new structural material - glass-metal composite is studied theoretically and experimentally. Different types of structures in the contact zone and its dimensions affect the strength characteristics of the composite. Knowledge about changing the width of the glass and steel contact zone after changing such parameters of the technological regime as temperature, holding time and use of solders will allow one to control the structure and characteristics of the glass-metal composite. Experimental measurements of the width of the diffusion zone in the glass-metal composite for different regimes and their statistical processing according to the full factor experiment are presented in this article. The results of analysis of some mechanical characteristics of the diffusion zone are presented: microhardness and modulus of elasticity for samples, prepared according to different processing regimes.
In vitro conjunctival incision repair by temperature-controlled laser soldering.

Science.gov (United States)

Norman, Galia; Rabi, Yaron; Assia, Ehud; Katzir, Abraham

2009-01-01

The common method of closing conjunctival incisions is by suturing, which is associated with several disadvantages. It requires skill to apply and does not always provide a watertight closure, which is required in some operations (e.g., glaucoma filtration). The purpose of the present study was to evaluate laser soldering as an alternative method for closing conjunctival incisions. Conjunctival incisions of 20 ex vivo porcine eyes were laser soldered using a temperature-controlled fiberoptic laser system and an albumin mixed with indocyanine green as a solder. The control group consisted of five repaired incisions by a 10-0 nylon running suture. The leak pressure of the repaired incisions was measured. The mean leak pressure in the laser-soldered group was 132 mm Hg compared to 4 mm Hg in the sutured group. There was no statistically significant difference in both the incision's length and distance from the limbus between the groups, before and after the procedure, indicating that there was no severe thermal damage. These preliminary results clearly demonstrate that laser soldering may be a useful method for achieving an immediate watertight conjunctival wound closure. This procedure is faster and easier to apply than suturing.
Rheological characterisation and printing performance of Sn/Ag/Cu solder pastes

International Nuclear Information System (INIS)

Durairaj, R.; Ramesh, S.; Mallik, S.; Seman, A.; Ekere, N.

2009-01-01

Lead-free solder paste printing process accounts for majority of the assembly defects in the electronic manufacturing industry. The study investigates rheological behaviour and stencil printing performance of the lead-free solder pastes (Sn/Ag/Cu). Oscillatory stress sweep test was carried out to study the visco-elastic behaviour of the lead-free solder pastes. The visco-elastic behaviour of the paste encompasses solid and liquid characteristic of the paste, which could be used to study the flow behaviour experienced by the pastes during the stencil printing process. From this study, it was found that the solid characteristics (G') is higher than the liquid characteristic (G'') for the pastes material. In addition, the results from the study showed that the solder paste with a large G' = G'' has a higher cohesiveness resulting in poor withdrawal of the paste during the stencil printing process. The phase angles (δ) was used to correlate the quality of the dense suspensions to the formulation of solder paste materials. This study has revealed the value of having a rheological measurement for explaining and characterising solder pastes for stencil printing. As the demand for lead free pastes increases rheological measurements can assist with the formulation or development of new pastes.
Dissolution rates of DWPF glasses from long-term PCT

International Nuclear Information System (INIS)

Ebert, W.L.; Tam, S.W.

1996-01-01

We have characterized the corrosion behavior of several Defense Waste Processing Facility (DWPF) reference waste glasses by conducting static dissolution tests with crushed glasses. Glass dissolution rates were calculated from measured B concentrations in tests conducted for up to five years. The dissolution rates of all glasses increased significantly after certain alteration phases precipitated. Calculation of the dissolution rates was complicated by the decrease in the available surface area as the glass dissolves. We took the loss of surface area into account by modeling the particles to be spheres, then extracting from the short-term test results the dissolution rate corresponding to a linear decrease in the radius of spherical particles. The measured extent of dissolution in tests conducted for longer times was less than predicted with this linear dissolution model. This indicates that advanced stages of corrosion are affected by another process besides dissolution, which we believe to be associated with a decrease in the precipitation rate of the alteration phases. These results show that the dissolution rate measured soon after the formation of certain alteration phases provides an upper limit for the long-term dissolution rate, and can be used to determine a bounding value for the source term for radionuclide release from waste glasses. The long-term dissolution rates measured in tests at 20,000 per m at 90 degrees C in tuff groundwater at pH values near 12 for the Environmental Assessment glass and glasses made with SRL 131 and SRL 202 frits, respectively
Reliability of lead-free solder joints with different PCB surface finishes under thermal cycling

Energy Technology Data Exchange (ETDEWEB)

Xia Yanghua [State Key Laboratory of Functional Materials for Informatics, Shanghai Institute of Microsystem and Information Technology, Chinese Academy of Sciences, Shanghai 200050 (China)], E-mail: xia_yanghua@hotmail.com; Xie Xiaoming [State Key Laboratory of Functional Materials for Informatics, Shanghai Institute of Microsystem and Information Technology, Chinese Academy of Sciences, Shanghai 200050 (China)

2008-04-24

The reliability of lead-free electronic assemblies under thermal cycling was investigated. Thin small outline package (TSOP) devices with FeNi leads were reflow soldered on FR4 PCB (printed circuit board) with Sn3.0Ag0.5Cu (wt%) solder. The effects of different PCB finishes (organic solderability preservative (OSP) and electroless nickel immersion gold (ENIG)) were studied. The results show that OSP finish reveals better performance than its ENIG counterparts. The crack originates at the fringe of heel fillet in both cases. The propagation of crack in the ENIG case is along the device/solder interface, while in the case of OSP, the crack extends parallel to the solder/PCB interface. When the OSP finishes are employed, many Cu6Sn5 precipitates form inside the bulk solder and have a strengthening effect on the solder joint, resulting in better reliability performance as compared to those with ENIG finishes.
Corrosion Reliability of Lead-free Solder Systems Used in Electronics

DEFF Research Database (Denmark)

Li, Feng; Verdingovas, Vadimas; Medgyes, Balint

2017-01-01

humidity/temperature cycling tests on soldered surface insulation resistance (SIR) comb pattern. Complimentary microstructural and phase analysis of solder alloys has been carried out using the scanning electron microscope (SEM), energy dispersive spectroscopy (EDS), and X-ray diffraction (XRD) methods...
Processing and Characterization of NiTi Shape Memory Alloy Particle Reinforced Sn-In Solders

National Research Council Canada - National Science Library

Chung, Kohn C

2006-01-01

.... In previous work, it was proposed that reinforcement of solder by NiTi shape memory alloy particles to form smart composite solder reduces the inelastic strain of the solder and hence, may enhance...
The glass furnace of the 17th Century of Sa Gerreria (Palma, Mallorca): Historical context and preliminary analysis of the materials

International Nuclear Information System (INIS)

Capella Galmes, M. A.; Albero Santacreu, D.

2015-01-01

In this paper the materials of the glass furnace of Sa Gerreria (Palma) dated in the second half of the 17th Century A.D. are analysed. On the one hand, we discuss the available information regarding this glass workshop as well as the raw material management strategies made during the studied period. On the other hand, we focus on the materials produced by this workshop and we carry out a preliminary archaeometrical analysis of the glass lumps, frits and slags recovered as well as some glass pieces by means of scanning electron microscope and X-ray dispersive energy. The final aim is to characterise the chemical composition and the properties of the raw materials used in this workshop as well as to approach some of the technical processes put in practice by the glass makers who inhabited Mallorca during the 17th Century. (Author)
Glass microspheres for medical applications

Science.gov (United States)

Conzone, Samuel David

Radioactive dysprosium lithium borate glass microspheres have been developed as biodegradable radiation delivery vehicles for the radiation synovectomy treatment of rheumatoid arthritis. Once injected into a diseased joint, the microspheres deliver a potent dose of radiation to the diseased tissue, while a non-uniform chemical reaction converts the glass into an amorphous, porous, hydrated dysprosium phosphate reaction product. The non-radioactive, lithium-borate component is dissolved from the glass (up to 94% weight loss), while the radioactive 165Dy reacts with phosphate anions in the body fluids, and becomes "chemically" trapped in a solid, dysprosium phosphate reaction product that has the same size as the un-reacted glass microsphere. Ethylene diamine tetraacetate (EDTA) chelation therapy can be used to dissolve the dysprosium phosphate reaction product after the radiation delivery has subsided. The dysprosium phosphate reaction product, which formed in vivo in the joint of a Sprague-Dawley rat, was dissolved by EDTA chelation therapy in 100 Gy) of localized beta radiation to a treatment site within the body, followed by complete biodegradability. The non-uniform reaction process is a desirable characteristic for a biodegradable radiation delivery vehicle, but it is also a novel material synthesis technique that can convert a glass to a highly porous materials with widely varying chemical composition by simple, low-temperature, glass/solution reaction. The reaction product formed by nonuniform reaction occupies the same volume as the un-reacted glass, and after drying for 1 h at 300°C, has a specific surface area of ≈200 m2/g, a pore size of ≈30 nm, and a nominal crushing strength of ≈10 MPa. Finally, rhenium glass microspheres, composed of micron-sized, metallic rhenium particles dispersed within a magnesium alumino borate glass matrix were produced by sintering ReO2 powder and glass frit at 1050°C. A 50 mg injection of radioactive rhenium glass
Interfacial reaction of Sn-based solder joint in the package system

Science.gov (United States)

Gu, Huandi

In this thesis, I report a study on the effect of the solder size on intermetallic layer formation by comparing the morphology change and growth rate of two different size solder joint aged at a same temperature for different aging time. The layer thickness and microstructure were analyzed using scanning electron microscopy (SEM). Photoshop was used to measure the thickness of intermetallic compound. Two different size of solder joints with composition of Sn-Ag-Cu (305) were used.
The effect of graphene on the intermetallic and joint strength of Sn-3.5Ag lead-free solder

Science.gov (United States)

Mayappan, R.; Salleh, A.; Andas, J.

2017-09-01

Solder has been widely used in electronic industry as interconnection for electronic packaging. European Union and Japan have restricted the use of Sn-Pb solder as it contains lead which can harmful to human health and environment. Due to this, many researches have been done in order to find a suitable replacement for the lead solder. Although many lead-free solders are available, the Sn-3.5Ag solder with the addition of graphene seem to be a suitable candidate. In this study, a 0.07 wt% graphene nanosheet was added into the Sn-3.5Ag solder and this composite solder was prepared under powder metallurgy method. The solder was reacted with copper substrate at 250 °C for one minute. For joint strength analysis, two copper strips were soldered together. The solder joint was aged at temperature 100 °C for 500 hours. Scanning Electron Microscope (SEM) was used to observe the interfacial reaction and Instron machine was used to determine the joint strength. Cu6Sn5 intermetallic layer was formed at the interface between the Cu substrate and the solders. Composite solder showed the retardation of the intermetallic growth compared to the plain solder. The thickness value of the intermetallic was used to calculate the growth rate the IMC. The graphene nanosheets added solder has lower growth rate which is 3.86 × 10-15 cm2/s compared to the plain solder 7.15 × 10-15 cm2/s. Shear strength analysis show that the composite solder has higher joint compared to the plain solder.
Effect of Preconditioning and Soldering on Failures of Chip Tantalum Capacitors

Science.gov (United States)

Teverovsky, Alexander A.

2014-01-01

Soldering of molded case tantalum capacitors can result in damage to Ta205 dielectric and first turn-on failures due to thermo-mechanical stresses caused by CTE mismatch between materials used in the capacitors. It is also known that presence of moisture might cause damage to plastic cases due to the pop-corning effect. However, there are only scarce literature data on the effect of moisture content on the probability of post-soldering electrical failures. In this work, that is based on a case history, different groups of similar types of CWR tantalum capacitors from two lots were prepared for soldering by bake, moisture saturation, and longterm storage at room conditions. Results of the testing showed that both factors: initial quality of the lot, and preconditioning affect the probability of failures. Baking before soldering was shown to be effective to prevent failures even in lots susceptible to pop-corning damage. Mechanism of failures is discussed and recommendations for pre-soldering bake are suggested based on analysis of moisture characteristics of materials used in the capacitors' design.
30 CFR 77.1112 - Welding, cutting, or soldering with arc or flame; safeguards.

Science.gov (United States)

2010-07-01

... 30 Mineral Resources 1 2010-07-01 2010-07-01 false Welding, cutting, or soldering with arc or... WORK AREAS OF UNDERGROUND COAL MINES Fire Protection § 77.1112 Welding, cutting, or soldering with arc or flame; safeguards. (a) When welding, cutting, or soldering with arc or flame near combustible...

Soldering and brazing safety guide: A handbook on space practice for those involved in soldering and brazing

Science.gov (United States)

This manual provides those involved in welding and brazing with effective safety procedures for use in performance of their jobs. Hazards exist in four types of general soldering and brazing processes: (1) cleaning; (2) application of flux; (3) application of heat and filler metal; and (4) residue cleaning. Most hazards during those operations can be avoided by using care, proper ventilation, protective clothing and equipment. Specific process hazards for various methods of brazing and soldering are treated. Methods to check ventilation are presented as well as a check of personal hygiene and good maintenance practices are stressed. Several emergency first aid treatments are described.
Visual detection of defects in solder joints

Science.gov (United States)

Blaignan, V. B.; Bourbakis, Nikolaos G.; Moghaddamzadeh, Ali; Yfantis, Evangelos A.

1995-03-01

The automatic, real-time visual acquisition and inspection of VLSI boards requires the use of machine vision and artificial intelligence methodologies in a new `frame' for the achievement of better results regarding efficiency, products quality and automated service. In this paper the visual detection and classification of different types of defects on solder joints in PC boards is presented by combining several image processing methods, such as smoothing, segmentation, edge detection, contour extraction and shape analysis. The results of this paper are based on simulated solder defects and a real one.
Projekt Frit Sind hjælper mennesker med social angst

DEFF Research Database (Denmark)

Moutamid, Mina El

2017-01-01

Social angst er en almindelig, men overset lidelse, som ofte er forbundet med isolation. Mange fortæller ikke om den angst, de oplever, til andre og kommer til at leve et liv med begrænsninger, som de kunne være foruden, hvis de fik hjælp. Angsten betyder også, at det kan være svært at komme...... hjemmefra og opsøge hjælp hos SIND eller andre rådgivninger. Frit Sind er et nyt tilbud i København til disse mennesker og har fokus på de specifikke behov, mennesker med social angst har....
A review on solder reflow and flux application for flip chip

Science.gov (United States)

Suppiah, Sarveshvaran; Ong, Nestor Rubio; Sauli, Zaliman; Sarukunaselan, Karunavani; Alcain, Jesselyn Barro; Visvanathan, Susthitha Menon; Retnasamy, Vithyacharan

2017-09-01

This paper encompassed of the evolution and key findings, critical technical challenges, solutions and bonding equipment of solder reflow in flip chip bonding. Upon scrutinizing researches done by others, it can be deduced that peak temperature, time above liquidus, soak temperature, soak time, cooling rate and reflow environment played a vital role in achieving the desired bonding profile. In addition, flux is also needed with the purpose of removing oxides/contaminations on bump surface as well as to promote wetting of solder balls. Electromigration and warpage are the two main challenges faced by solder reflow process which can be overcome by the advancement in under bump metallization (UBM) and substrate technology. The review is ended with a brief description of the current equipment used in solder reflow process.
30 CFR 75.1106 - Welding, cutting, or soldering with arc or flame underground.

Science.gov (United States)

2010-07-01

... 30 Mineral Resources 1 2010-07-01 2010-07-01 false Welding, cutting, or soldering with arc or... Protection § 75.1106 Welding, cutting, or soldering with arc or flame underground. [Statutory Provisions] All welding, cutting, or soldering with arc or flame in all underground areas of a coal mine shall, whenever...
Influence of Difference Solders Volume on Intermetallic Growth of Sn-4.0Ag-0.5Cu/ENEPIG

Directory of Open Access Journals (Sweden)

Saliza Azlina O.

2016-01-01

Full Text Available In recent years, portable electronic packaging products such as smart phones, tablets, notebooks and other gadgets have been developed with reduced size of component packaging, light weight, high speed and with enhanced performance. Thus, flip chip technology with smaller solder sphere sizes that would produce fine solder joint interconnections have become essential in order to fulfill these miniaturization requirements. This study investigates the interfacial reactions and intermetallics formation during reflow soldering and isothermal aging between Sn-4.0Ag-0.5Cu (SAC405 and electroless nickel/immersion palladium/immersion gold (EN(PEPIG. Solder diameters of 300 μm and 700 μm were used to compare the effect of solder volume on the solder joint microstructure. The solid state isothermal aging was performed at 125°C starting from 250 hours until 2000 hours. The results revealed that only (Cu,Ni6Sn5 IMC was found at the interface during reflow soldering while both (Cu,Ni6Sn5 and (Ni,Cu3Sn4 IMC have been observed after aging process. Smaller solder sizes produced thinner IMC than larger solder joints investigated after reflow soldering, whereas the larger solders produced thinner IMC than the smaller solders after isothermal aging. Aging duration of solder joints has been found to be increase the IMC’s thickness and changed the IMC morphologies to spherical-shaped, compacted and larger grain size.
Final Report - Glass Formulation Development and Testing for DWPF High AI2O3 HLW Sludges, VSL-10R1670-1, Rev. 0, dated 12/20/10

Energy Technology Data Exchange (ETDEWEB)

Kruger, Albert A.; Pegg, I. L.; Kot, W. K.; Gan, H.; Matlack, K. S.

2013-11-13

The principal objective of the work described in this Final Report is to develop and identify glass frit compositions for a specified DWPF high-aluminum based sludge waste stream that maximizes waste loading while maintaining high production rate for the waste composition provided by ORP/SRS. This was accomplished through a combination of crucible-scale, vertical gradient furnace, and confirmation tests on the DM100 melter system. The DM100-BL unit was selected for these tests. The DM100-BL was used for previous tests on HLW glass compositions that were used to support subsequent tests on the HLW Pilot Melter. It was also used to process compositions with waste loadings limited by aluminum, bismuth, and chromium, to investigate the volatility of cesium and technetium during the vitrification of an HLW AZ-102 composition, to process glass formulations at compositional and property extremes, and to investigate crystal settling on a composition that exhibited one percent crystals at 963{degrees}C (i.e., close to the WTP limit). The same melter was selected for the present tests in order to maintain comparisons between the previously collected data. The tests provide information on melter processing characteristics and off-gas data, including formation of secondary phases and partitioning. Specific objectives for the melter tests are as follows: Determine maximum glass production rates without bubbling for a simulated SRS Sludge Batch 19 (SB19). Demonstrate a feed rate equivalent to 1125 kg/m{sup 2}/day glass production using melt pool bubbling. Process a high waste loading glass composition with the simulated SRS SB19 waste and measure the quality of the glass product. Determine the effect of argon as a bubbling gas on waste processing and the glass product including feed processing rate, glass redox, melter emissions, etc.. Determine differences in feed processing and glass characteristics for SRS SB19 waste simulated by the co-precipitated and direct
Interfacial microstructures and solder joint strengths of the Sn-8Zn-3Bi and Sn-9Zn-lAl Pb-free solder pastes on OSP finished printed circuit boards

Energy Technology Data Exchange (ETDEWEB)

Lin, C.-T. [Department of Materials Science and Engineering, National United University, 1 Lein-Da, Kung-Ching Li, Miaoli 36003, Taiwan (China); Electronics and Optoelectronics Research Laboratories, Industrial Technology Research Institute, 195 Section 4, Chung-Hsing Road, Chutung, Hsinchu 31040, Taiwan (China); Hsi, C.-S. [Department of Materials Science and Engineering, National United University, 1 Lein-Da, Kung-Ching Li, Miaoli 36003, Taiwan (China); Wang, M.-C. [Faculty of Fragrance and Cosmetics, Kaohsiung Medical University, 100 Shih-Chuan 1st Road, Kaohsiung 807, Taiwan (China)], E-mail: mcwang@kmu.edu.tw; Chang, T.-C.; Liang, M.-K. [Electronics and Optoelectronics Research Laboratories, Industrial Technology Research Institute, 195 Section 4, Chung-Hsing Road, Chutung, Hsinchu 31040, Taiwan (China)

2008-07-14

Two kinds of lead-free solders, Sn-8Zn-3Bi and Sn-9Zn-lAl, were used to mount passive components onto printed circuit boards via a re-flow soldering process. The samples were stored at 150 deg. C for 200, 400, 600, 800, and 1100 h. The microstructures of the samples after aged at 150 deg. C for various times were characterized using optical microscopy (OM), scanning electron microscopy (SEM), energy dispersive spectrometry (EDS) and the analyzed of solder joint shear strengths. The joint strength between Sn-8Zn-3Bi and Cu pad was about 4.0 {+-} 0.3 kg, while the strength between Sn-9Zn-lAl and Cu pad had values of 2.6 {+-} 0.1 kg. Both kinds of solder joints exhibited reduced strengths with increasing aging times. After aging at 150 deg. C for 1100 h, the joints strengths of Sn-8Zn-3Bi and Sn-9Zn-lAl were 1.8 {+-} 0.3 and 1.7 {+-} 0.3 kg, respectively. Both the Sn-8Zn-3Bi and Sn-9Zn-lAl joints showed brittle fracture behaviors. A flat layer of Cu{sub 5}Zn{sub 8} intermetallic compound (IMC) was formed between Sn-8Zn-3Bi solder and Cu pad after reflow. When the aging time was increased to 400 h, Zn-depletion and formation of Cu{sub 6}Sn{sub 5} IMC were observed in the solders due to the interaction between the tin and zinc compounds. The interaction between Sn-9Zn-lAl solder and Cu pad had similar behavior, however, Cu{sub 6}Sn{sub 5} IMC formed in Sn-9Zn-lAl solder when after aging at 150 deg. C for 600 h. As the aging time increased, both types of solders generated clear IMC spalling layers with large and continuous voids. Those voids substantially decreased the joint strength.
Automation of experimental research of waveguide paths induction soldering

Science.gov (United States)

Tynchenko, V. S.; Petrenko, V. E.; Kukartsev, V. V.; Tynchenko, V. V.; Antamoshkin, O. A.

2018-05-01

The article presents an automated system of experimental studies of the waveguide paths induction soldering process. The system is a part of additional software for a complex of automated control of the technological process of induction soldering of thin-walled waveguide paths from aluminum alloys, expanding its capabilities. The structure of the software product, the general appearance of the controls and the potential application possibilities are presented. The utility of the developed application by approbation in a series of field experiments was considered and justified. The application of the experimental research system makes it possible to improve the process under consideration, providing the possibility of fine-tuning the control regulators, as well as keeping the statistics of the soldering process in a convenient form for analysis.
Optimization of the soldering process by the DMAIC methodology

Directory of Open Access Journals (Sweden)

Michał Zasadzień

2016-06-01

Full Text Available The chapter presents the use of the DMAIC method for the analysis and improvement of the process of soldering pins in a plug connecting a bundle of wires to the board of a controller; a part of the steering system of a car. The main problem in the soldering process, that is an unsatisfactory share of bad soldered connections between the board and the plug and the instability of that number, was identified by means of a five-phase improvement process. Key points and main causes of the defect were pointed out, and process improvement measures were suggested. Due to the analysis conducted and the correct implementation of improvement measures the share of defective connections has been decreased twofold.
Contamination profile on typical printed circuit board assemblies vs soldering process

DEFF Research Database (Denmark)

Conseil, Helene; Jellesen, Morten Stendahl; Ambat, Rajan

2014-01-01

Purpose – The purpose of this paper was to analyse typical printed circuit board assemblies (PCBAs) processed by reflow, wave or selective wave soldering for typical levels of process-related residues, resulting from a specific or combination of soldering processes. Typical solder flux residue...... structure was identified by Fourier transform infrared spectroscopy, while the concentration was measured using ion chromatography, and the electrical properties of the extracts were determined by measuring the leak current using a twin platinum electrode set-up. Localized extraction of residue was carried...
Effects of rework on adhesion of Pb-In soldered gold thick films

International Nuclear Information System (INIS)

Gehman, R.W.; Becka, G.A.; Losure, J.A.

1982-02-01

The feasibility of repeatedly reworking Pb-In soldered joints on gold thick films was evaluated. Nailhead adhesion tests on soldered thick films typically resulted in failure within the bulk solder (50 In-50 Pb). Average strengths increased with each rework, and the failure mode changed. An increase in metalization lift-off occurred with successive reworks. An investigation was initiated to determine why these changes occurred. Based on this work, the thick film adhesion to the substrate appeared to be lowered by indium reduction of cadmium oxide and by formation of a weak, brittle intermetallic compound, Au 9 In 4 . It was concluded that two solder reworks could be conducted without significant amounts of metallization lift-off during nailhead testing
Effect of gamma radiation on micromechanical hardness of lead-free solder joint

Energy Technology Data Exchange (ETDEWEB)

Paulus, Wilfred [Universiti Kebangsaan Malaysia, Bangi, 43600 Kajang, Selangor (Malaysia); Malaysian Nuclear Agency, Bangi, 43000 Kajang, Selangor (Malaysia); Rahman, Irman Abdul; Jalar, Azman; Kamil, Insan; Bakar, Maria Abu [Universiti Kebangsaan Malaysia, Bangi, 43600 Kajang, Selangor (Malaysia); Yusoff, Wan Yusmawati Wan [Universiti Pertahanan Nasional Malaysia, Kem Sg. Besi, 57000 Kuala Lumpur (Malaysia)

2015-09-25

Lead-free solders are important material in nano and microelectronic surface mounting technology for various applications in bio medicine, environmental monitoring, spacecraft and satellite instrumentation. Nevertheless solder joint in radiation environment needs higher reliability and resistance to any damage caused by ionizing radiations. In this study a lead-free 99.0Sn0.3Ag0.7Cu wt.% (SAC) solder joint was developed and subjected to various doses of gamma radiation to investigate the effects of the ionizing radiation to micromechanical hardness of the solder. Averaged hardness of the SAC joint was obtained from nanoindentation test. The results show a relationship between hardness values of indentations and the increment of radiation dose. Highest mean hardness, 0.2290 ± 0.0270 GPa was calculated on solder joint which was exposed to 5 Gray dose of gamma radiation. This value indicates possible radiation hardening effect on irradiated solder. The hardness gradually decreased to 0.1933 ± 0.0210 GPa and 0.1631 ± 0.0173 GPa when exposed to doses 50 and 500 gray respectively. These values are also lower than the hardness of non irradiated sample which was calculated as 0.2084 ± 0.0.3633 GPa indicating possible radiation damage and needs further related atomic dislocation study.
The Impact of Waste Loading on Viscosity in the Frit 418-SB3 System

International Nuclear Information System (INIS)

PEELER, DAVID

2004-01-01

In this report, data are provided to gain insight into the potential impact of a lower viscosity glass on melter stability (i.e., pressure spikes, cold cap behavior) and/or pour stream stability. High temperature viscosity data are generated for the Frit 418-SB3 system as a function of waste loading (from 30 to 45 percent) and compared to similar data from other systems that have been (or are currently being) processed through the Defense Waste Processing Facility (DWPF) melter. The data are presented in various formats to potentially align the viscosity data with physical observations at various points in the melter system or critical DWPF processing unit operations. The expectations is that the data will be provided adequate insight into the vitrification parameters which might evolve into working solutions as DWPF strives to maximize waste throughput. This report attempts to provide insight into a physical interpretation of the data from a DWPF perspective. The theories present ed are certainly not an all inclusive list and the order in which they are present does imply a ranking, probability, or likelihood that the proposed theory is even plausible. The intent of this discussion is to provide a forum in which the viscosity data can be discussed in relation to possible mechanisms which could potentially lead to a workable solution as discussed in relation to possible solution as higher overall attainment is striven for during processing of the current or future sludge batches
Comparative shear tests of some low temperature lead-free solder pastes

Science.gov (United States)

Branzei, Mihai; Plotog, Ioan; Varzaru, Gaudentiu; Cucu, Traian C.

2016-12-01

The range of electronic components and as a consequence, all parts of automotive electronic equipment operating temperatures in a vehicle is given by the location of that equipment, so the maximum temperature can vary between 358K and 478K1. The solder joints could be defined as passive parts of the interconnection structure of automotive electronic equipment, at a different level, from boards of electronic modules to systems. The manufacturing costs reduction necessity and the RoHS EU Directive3, 7 consequences generate the trend to create new Low-Temperature Lead-Free (LTLF) solder pastes family9. In the paper, the mechanical strength of solder joints and samples having the same transversal section as resistor 1206 case type made using the same LTLF alloys into Vapour Phase Soldering (VPS) process characterized by different cooling rates (slow and rapid) and two types of test PCBs pads finish, were benchmarked at room temperature. The presented work extends the theoretical studies and experiments upon heat transfer in VPSP in order to optimize the technology for soldering process (SP) of automotive electronic modules and could be extended for home and modern agriculture appliances industry. The shear forces (SF) values of the LTLF alloy samples having the same transversal section as resistor 1206 case type will be considered as references values of a database useful in the new solder alloy creation processes and their qualification for automotive electronics domain.
Manipulation and soldering of carbon nanotubes using atomic force microscope

International Nuclear Information System (INIS)

Kashiwase, Yuta; Ikeda, Takayuki; Oya, Takahide; Ogino, Toshio

2008-01-01

Manipulation of carbon nanotubes (CNTs) by an atomic force microscope (AFM) and soldering of CNTs using Fe oxide nanoparticles are described. We succeeded to separate a CNT bundle into two CNTs or CNT bundles, to move the separated CNT to a desirable position, and to bind it to another bundle. For the accurate manipulation, load of the AFM cantilever and frequency of the scan were carefully selected. We soldered two CNTs using an Fe oxide nanoparticle prepared from a ferritin molecule. The adhesion forces between the soldered CNTs were examined by an AFM and it was found that the CNTs were bound, though the binding force was not strong
Effect of temperature and flux concentration on soldering of base metal.

Science.gov (United States)

Lee, S Y; Lin, C T; Wang, M H; Tseng, H; Huang, H M; Dong, D R; Pan, L C; Shih, Y H

2000-12-01

The present study used the acoustic emission (AE) technique to evaluate interactions among soldering temperature, flux treatment, and the resultant ultimate tensile strength (UTS). Scanning electron microscopy (SEM) was used to examine fracture surfaces of the solder joints. Specimens were cast from removable partial denture alloy and then placed in a jig with a gap distance of 1.0 mm. A high-frequency soldering machine with an optical pyrometer was used for soldering at 1150 degrees C and 1200 degrees C, respectively. The flux concentrations were 67% and 75%. The soldered specimens were subjected to tensile test at a crosshead speed of 0.05 mm/min. During testing, acoustic emissions in the frequency range of 100--1200 kHz were collected, filtered, recorded, and processed by a sensing device. The results were analysed by ANOVA and Tukey LSD test. UTS at different temperatures showed no significant difference according to either mechanical or acoustic results. But in the 1200 degrees C group, the UTSs and AE counts showed significant differences (Pacoustic signals within the elastic deformation zone, while the 67% flux subgroup produced similar signals within the plastic deformation zone, either beyond the 0.2% yield point or before fracture.
Effect of Solder-Joint Geometry on the Low-Cycle Fatigue Behavior of Sn- xAg-0.7Cu

Science.gov (United States)

Lee, Hwa-Teng; Huang, Kuo-Chen

2016-12-01

Low-cycle fatigue tests of Sn-Ag-Cu (SAC) Pb-free solder joints under fixed displacement were performed to evaluate the influence of Ag content (0-3 wt.%) and solder-joint geometry (barrel and hourglass types) on solder-joint fatigue behavior and reliability. The solder joints were composed of fine particles of Ag3Sn and Cu6Sn5, which aggregated as an eutectic constituent at grain boundaries of the primary β-Sn phase and formed a dense network structure. A decrease in the Ag content resulted in coarsening of the β-Sn and eutectic phases, which, in turn, decreased the strength of the joint and caused earlier failure. Solder joints in the hourglass form exhibited better fatigue performance with longer life than barrel-type joints. The sharp contact angle formed between the solder and the Cu substrate by the barrel-type joints concentrated stress, which compromised fatigue reliability. The addition of Ag to the solder, however, enhanced fatigue performance because of strengthening caused by Ag3Sn formation. The cracks of the barrel-type SAC solder joints originated mostly at the contact corner and propagated along the interfacial layer between the interfacial intermetallic compound (IMC) and solder matrix. Hourglass-type solder joints, however, demonstrated both crack initiation and propagation in the solder matrix (solder mode). The addition of 1.5-2.0 wt.% Ag to SAC solder appears to enhance the fatigue performance of solder joints while maintaining sufficient strength.
Yield Stress Reduction of DWPF Melter Feed Slurries

International Nuclear Information System (INIS)

Stone, M.E.; Smith, M.E.

2007-01-01

The Defense Waste Processing Facility (DWPF) at the Savannah River Site vitrifies High Level Waste for repository internment. The process consists of three major steps: waste pretreatment, vitrification, and canister decontamination/sealing. The HLW consists of insoluble metal hydroxides and soluble sodium salts. The pretreatment process acidifies the sludge with nitric and formic acids, adds the glass formers as glass frit, then concentrates the resulting slurry to approximately 50 weight percent (wt%) total solids. This slurry is fed to the joule-heated melter where the remaining water is evaporated followed by calcination of the solids and conversion to glass. The Savannah River National Laboratory (SRNL) is currently assisting DWPF efforts to increase throughput of the melter. As part of this effort, SRNL has investigated methods to increase the solids content of the melter feed to reduce the heat load required to complete the evaporation of water and allow more of the energy available to calcine and vitrify the waste. The process equipment in the facility is fixed and cannot process materials with high yield stresses, therefore increasing the solids content will require that the yield stress of the melter feed slurries be reduced. Changing the glass former added during pretreatment from an irregularly shaped glass frit to nearly spherical beads was evaluated. The evaluation required a systems approach which included evaluations of the effectiveness of beads in reducing the melter feed yield stress as well as evaluations of the processing impacts of changing the frit morphology. Processing impacts of beads include changing the settling rate of the glass former (which effects mixing and sampling of the melter feed slurry and the frit addition equipment) as well as impacts on the melt behavior due to decreased surface area of the beads versus frit. Beads were produced from the DWPF process frit by fire polishing. The frit was allowed to free fall through a flame
An evaluation of electric melter refractories for contact with glass used for the immobilisation of nuclear waste

International Nuclear Information System (INIS)

Hayward, P.J.; George, I.M.

1987-01-01

Corrosion tests have been performed on twelve candidate refractories in contact with borosilicate, titanosilicate, and aluminosilicate melts, in order to rank them for use in an all-electric melter for the production of waste form materials suitable for immobilising nuclear fuel recycle wastes. Viscosities and electrical conductivities of the melts have also been measured to enable optimum processing conditions to be determined. Of the materials tested, the choice of glass contact refractory for the Joule heated melting of the borosilicate and titanosilicate compositions is Monofrax K3 or SEPR 2161, in conjunction with tin oxide electrodes. The aluminosilicate glass waste form would require an alternative method of production (sol-gel processing, or sintering of a precursor frit), because of its high viscosity. (author)

Microstructure and Properties of Porous Si3N4/Dense Si3N4 Joints Bonded Using RE–Si–Al–O–N (RE = Y or Yb Glasses

Directory of Open Access Journals (Sweden)

Ling Li

2017-11-01

Full Text Available The joining of porous Si3N4 to dense Si3N4 ceramics has been successfully performed using mixed RE2O3 (RE = Y or Yb, Al2O3, SiO2, and α-Si3N4 powders. The results suggested that the α-Si3N4 powders partly transformed into β-SiAlON and partly dissolved into oxide glass to form oxynitride glass. Thus, composites of glass/β-SiAlON-ceramic formed in the seam of joints. Due to the capillary action of the porous Si3N4 ceramic, the molten glass solder infiltrated into the porous Si3N4 ceramic side during the joining process and formed the “infiltration zone” with a thickness of about 400 μm, which contributed to the heterogeneous distribution of the RE–Si–Al–O–N glasses in the porous Si3N4 substrate. In-situ formation of β-SiAlON in the seam resulted in a high bonding strength. The maximum bending strength of 103 MPa and 88 MPa was reached for the porous Si3N4/dense Si3N4 joints using Y–Si–Al–O–N and Yb–Si–Al–O–N glass solders, respectively.
Current Problems and Possible Solutions in High-Temperature Lead-Free Soldering

Czech Academy of Sciences Publication Activity Database

Kroupa, Aleš; Andersson, D.; Hoo, N.; Pearce, J.; Watson, A.; Dinsdale, A.; Mucklejohn, S.

2012-01-01

Roč. 21, č. 5 (2012), s. 629-637 ISSN 1059-9495 Institutional support: RVO:68081723 Keywords : lead-free soldering, * materials for high-temperature LF * new technologies for HT lead-free soldering Subject RIV: BJ - Thermodynamics Impact factor: 0.915, year: 2012
Effect of Strain Rate on Joint Strength and Failure Mode of Lead-Free Solder Joints

Science.gov (United States)

Lin, Jian; Lei, Yongping; Fu, Hanguang; Guo, Fu

2018-03-01

In surface mount technology, the Sn-3.0Ag-0.5Cu solder joint has a shorter impact lifetime than a traditional lead-tin solder joint. In order to improve the impact property of SnAgCu lead-free solder joints and identify the effect of silver content on tensile strength and impact property, impact experiments were conducted at various strain rates on three selected SnAgCu based solder joints. It was found that joint failure mainly occurred in the solder material with large plastic deformation under low strain rate, while joint failure occurred at the brittle intermetallic compound layer without any plastic deformation at a high strain rate. Joint strength increased with the silver content in SnAgCu alloys in static tensile tests, while the impact property of the solder joint decreased with increasing silver content. When the strain rate was low, plastic deformation occurred with failure and the tensile strength of the Sn-3.0Ag-0.5Cu solder joint was higher than that of Sn-0.3Ag-0.7Cu; when the strain rate was high, joint failure mainly occurred at the brittle interface layer and the Sn-0.3Ag-0.7Cu solder joint had a better impact resistance with a thinner intermetallic compound layer.
Tissue soldering with biodegradable polymer films: in-vitro investigation of hydration effects on weld strength

Science.gov (United States)

Sorg, Brian S.; Welch, Ashley J.

2001-05-01

Previous work demonstrated increased breaking strengths of tissue repaired with liquid albumin solder reinforced with a biodegradable polymer film compared to unreinforced control specimens. It was hypothesized that the breaking strength increase was due to reinforcement of the liquid solder cohesive strength. Immersion in a moist environment can decrease the adhesion of solder to tissue and negate any strength benefits gained from reinforcement. The purpose of this study was to determine if hydrated specimens repaired with reinforced solder would still be stronger than unreinforced controls. A 50%(w/v) bovine serum albumin solder with 0.5 mg/mL Indocyanine Green dye was used to repair an incision in bovine aorta. The solder was coagulated with 806-nm diode laser light. A poly(DL-lactic- co-glycolic acid) film was used to reinforce the solder (the controls had no reinforcement). The repaired tissues were immersed in phosphate buffered saline for time periods of 1 and 2 days. The breaking strengths of all of the hydrated specimens decreased compared to the acute breaking strengths. However, the reinforced specimens still had larger breaking strengths than the unreinforced controls. These results indicate that reinforcement of a liquid albumin solder may have the potential to improve the breaking strength in a clinical setting.
An evaluation of the lap-shear test for Sn-rich solder/Cu couples: Experiments and simulation

Science.gov (United States)

Chawla, N.; Shen, Y.-L.; Deng, X.; Ege, E. S.

2004-12-01

The lap-shear technique is commonly used to evaluate the shear, creep, and thermal fatigue behavior of solder joints. We have conducted a parametric experimental and modeling study, on the effect of testing and geometrical parameters on solder/copper joint response in lap-shear. It was shown that the farfield applied strain is quite different from the actual solder strain (measured optically). Subtraction of the deformation of the Cu substrate provides a reasonable approximation of the solder strain in the elastic regime, but not in the plastic regime. Solder joint thickness has a profound effect on joint response. The solder response moves progressively closer to “true” shear response with increasing joint thickness. Numerical modeling using finite-element analyses were performed to rationalize the experimental findings. The same lap-shear configuration was used in the simulation. The input response for solder was based on the experimental tensile test result on bulk specimens. The calculated shear response, using both the commonly adopted far-field measure and the actual shear strain in solder, was found to be consistent with the trends observed in the lap-shear experiments. The geometric features were further explored to provide physical insight into the problem. Deformation of the substrate was found to greatly influence the shear behavior of the solder.
LSA glass-ceramic tiles made by powder pressing; Obtencao de placas vitroceramicas do sistema LSA utilizando a prensagem de pos

Energy Technology Data Exchange (ETDEWEB)

Figueira, F.C.; Bertan, F.M. [Colorminas Colorificio e Mineracao, Icara, SC (Brazil); Riella, H.G. [Universidade Federal de Santa Catarina (UFSC), Florianopolis, SC (Brazil). Programa de Pos-Graduaco em Engenharia Quimica; Uggioni, E. [Universidade do Extremo Sul Catarinense (UFSC), Florianopolis, SC (Brazil). Curso de Engenharia de Materiais; Bernardin, A.M., E-mail: amb@unesc.ne [Servico Nacional de Aprendizagem Industrial (SENAI), Tijucas, SC (Brazil). Dept. de Tecnologia em Ceramica

2009-07-01

A low cost alternative for the production of glass-ceramic materials is the pressing of the matrix glass powders and its consolidation simultaneously with crystallization in a single stage of sintering. The main objective of this work was to obtain LSA glass ceramics with low thermal expansion, processed by pressing and sintering a ceramic frit powder. The raw materials were homogenized and melted (1480 deg C, 80min), and the melt was poured in water. The glass was chemically (XRF and AAS) and thermally (DTA, 10 deg C/min, air) characterized, and then ground (60min and 120min). The ground powders were characterized (laser diffraction) and compressed (35MPa and 45MPa), thus forming four systems. The compacts were dried (150 deg C, 24h) and sintered (1175 deg C and 1185 deg C, 10 deg C/min). Finally, the glass-ceramics were characterized by microstructural analysis (SEM and XRD), mechanical behavior ({sigma}bending) and thermal analysis ({alpha}). The best results for thermal expansion were those for the glass-ceramics processed with smaller particle size and greater compaction pressure. (author)
Properties and Microstructures of Sn-Ag-Cu-X Lead-Free Solder Joints in Electronic Packaging

Directory of Open Access Journals (Sweden)

Lei Sun

2015-01-01

Full Text Available SnAgCu solder alloys were considered as one of the most popular lead-free solders because of its good reliability and mechanical properties. However, there are also many problems that need to be solved for the SnAgCu solders, such as high melting point and poor wettability. In order to overcome these shortcomings, and further enhance the properties of SnAgCu solders, many researchers choose to add a series of alloying elements (In, Ti, Fe, Zn, Bi, Ni, Sb, Ga, Al, and rare earth and nanoparticles to the SnAgCu solders. In this paper, the work of SnAgCu lead-free solders containing alloying elements and nanoparticles was reviewed, and the effects of alloying elements and nanoparticles on the melting temperature, wettability, mechanical properties, hardness properties, microstructures, intermetallic compounds, and whiskers were discussed.
Study on interfacial reaction between lead-free solders and alternative surface finishes

International Nuclear Information System (INIS)

Siti Rabiatul Aisha; Ourdjini, A.; Saliza Osman

2007-01-01

This study investigates the interfacial reactions occurring during reflow soldering between Sn-Ag-Cu lead-free solder and two surface finishes: electroless nickel/ immersion gold (ENIG) and immersion silver (IAg). The study focuses on interfacial reactions evolution and growth kinetics of intermetallic compounds (IMC) formed during soldering and isothermal ageing at 150 degree Celsius for up to 2000 hours. Optical and scanning electron microscopy were used to measure IMC thickness and examine the morphology of IMC respectively, whereas the IMC phases were identified by energy dispersive X-ray analysis (EDX). The results showed that the IMC formed on ENIG finish is thinner compared to that formed on IAg finish. For IAg surface finish, Cu 6 Sn 5 IMCs with scallop morphology are formed at the solder/ surface finish interface after reflow while a second IMC, Cu 3 Sn was formed between the copper and Cu 6 Sn 5 IMC after the isothermal ageing treatment. For ENIG surface finish both (Cu,Ni) 6 Sn 5 and (Ni,Cu) 3 Sn 4 are formed after soldering. Isothermal aging of the solder joints formed on ENIG finish was found to have a significant effect on the morphology of the intermetallics by transforming to more spherical and denser morphology in addition to increase i their thickness with increased ageing time. (author)
The critical oxide thickness for Pb-free reflow soldering on Cu substrate

Energy Technology Data Exchange (ETDEWEB)

Chung, C. Key [Department of Materials Science and Engineering, National Taiwan University, No. 1, Sec. 4, Roosevelt Road, Taipei, 10617, Taiwan (China); Assembly Test Global Materials, Intel Microelectronics Asia Ltd, B1, No. 205, Tun-Hwa North Road, 10595 Taipei, Taiwan (China); Chen, Y.J.; Li, C.C. [Department of Materials Science and Engineering, National Taiwan University, No. 1, Sec. 4, Roosevelt Road, Taipei, 10617, Taiwan (China); Kao, C.R., E-mail: crkao@ntu.edu.tw [Department of Materials Science and Engineering, National Taiwan University, No. 1, Sec. 4, Roosevelt Road, Taipei, 10617, Taiwan (China)

2012-06-01

Oxidation is an undesirable effect of reflow soldering. Non-wetting occurs when the oxide layer grows above the critical thickness. Characterizing the critical oxide thickness for soldering is challenging due to oxide's nano-scale thickness and irregular topographic surface. In this paper, the critical copper oxide thickness was characterized by Time-of-Flight Secondary Ion Mass Spectrometry, Scanning Electron Microscopy, Energy-Dispersive X-ray spectroscopy, and Transmission Electron Microscopy. Copper substrates were coated with an Organic-Solderable-Preservative (OSP) layer and baked at 150 Degree-Sign C and 85% Relative Humidity for different amounts of time. The onset of the non-wetting phenomenon occurred when the oxide thickness reached 18 {+-} 5 nm. As the oxide grew beyond this critical thickness, the percentage of non-wetting solder joint increased exponentially. The growth of the oxide thickness followed a parabolic rate law. The rate constant of oxidation was 0.6 Multiplication-Sign 10{sup -15} cm{sup 2} min{sup -1}. Oxidation resulted from interdiffusion of copper and oxygen atoms through the OSP and oxide layers. The oxidation mechanism will be presented and discussed. - Highlights: Black-Right-Pointing-Pointer Critical oxide thickness for Pb free solder on Cu substrate is 18 {+-} 5 nm. Black-Right-Pointing-Pointer Above the critical oxide, non-wet solder joint increases exponentially. Black-Right-Pointing-Pointer A maximum 13-nm oxide thickness is suggested for good solder joint. Black-Right-Pointing-Pointer Initial growth of oxide thickness is logarithmic and then parabolic after 12 nm. Black-Right-Pointing-Pointer Thick oxide (360-560 nm) is formed as pores shorten the oxidation path.
Effect of gap distance on tensile strength of preceramic base metal solder joints.

Science.gov (United States)

Fattahi, Farnaz; Motamedi, Milad

2011-01-01

In order to fabricate prostheses with high accuracy and durability, soldering techniques have been introduced to clinical dentistry. However, these prostheses always fail at their solder joints. The purpose of this study was to evaluate the effect of gap distance on the tensile strength of base metal solder joints. Based on ADA/ISO 9693 specifications for tensile test, 40 specimens were fabricated from a Ni-Cr alloy and cut at the midpoint of 3-mm diameter bar and placed at desired positions by a specially designed device. The specimens were divided into four groups of 10 samples according to the desired solder gap distance: Group1: 0.1mm; Group2: 0.25mm; Group3: 0.5mm; and Group4: 0.75mm. After soldering, specimens were tested for tensile strength by a universal testing machine at a cross-head speed of 0.5mm/min with a preload of 10N. The mean tensile strength values of the groups were 162, 307.8, 206.1 and 336.7 MPa, respectively. The group with 0.75-mm gap had the highest and the group with 0.1-mm gap had the lowest tensile strength. Bonferroni test showed that Group1 and Group4 had statistically different values (P=0.023), but the differences between other groups were not sig-nificant at a significance level of 0.05. There was no direct relationship between increasing soldering gap distance and tensile strength of the solder joints.
Polyphase ceramic and glass-ceramic forms for immobilizing ICPP high-level nuclear waste

International Nuclear Information System (INIS)

Harker, A.B.; Flintoff, J.F.

1984-01-01

Polyphase ceramic and glass-ceramic forms have been consolidated from simulated Idaho Chemical Processing Plant wastes by hot isostatic pressing calcined waste and chemical additives by 1000 0 C or less. The ceramic forms can contain over 70 wt% waste with densities ranging from 3.5 to 3.85 g/cm 3 , depending upon the formulation. Major phases are CaF 2 , CaZrTi 207 , CaTiO 3 , monoclinic ZrO 2 , and amorphous intergranular material. The relative fraction of the phases is a function of the chemical additives (TiO 2 , CaO, and SiO 2 ) and consolidation temperature. Zirconolite, the major actinide host, makes the ceramic forms extremely leach resistant for the actinide simulant U 238 . The amorphous phase controls the leach performance for Sr and Cs which is improved by the addition of SiO 2 . Glass-ceramic forms were also consolidated by HIP at waste loadings of 30 to 70 wt% with densities of 2.73 to 3.1 g/cm 3 using Exxon 127 borosilicate glass frit. The glass-ceramic forms contain crystalline CaF 2 , Al 203 , and ZrSi 04 (zircon) in a glass matrix. Natural mineral zircon is a stable host for 4+ valent actinides. 17 references, 3 figures, 5 tables
Feed Preparation for Source of Alkali Melt Rate Tests

International Nuclear Information System (INIS)

Stone, M. E.; Lambert, D. P.

2005-01-01

The purpose of the Source of Alkali testing was to prepare feed for melt rate testing in order to determine the maximum melt-rate for a series of batches where the alkali was increased from 0% Na 2 O in the frit (low washed sludge) to 16% Na 2 O in the frit (highly washed sludge). This document summarizes the feed preparation for the Source of Alkali melt rate testing. The Source of Alkali melt rate results will be issued in a separate report. Five batches of Sludge Receipt and Adjustment Tank (SRAT) product and four batches of Slurry Mix Evaporator (SME) product were produced to support Source of Alkali (SOA) melt rate testing. Sludge Batch 3 (SB3) simulant and frit 418 were used as targets for the 8% Na 2 O baseline run. For the other four cases (0% Na 2 O, 4% Na 2 O, 12% Na 2 O, and 16% Na 2 O in frit), special sludge and frit preparations were necessary. The sludge preparations mimicked washing of the SB3 baseline composition, while frit adjustments consisted of increasing or decreasing Na and then re-normalizing the remaining frit components. For all batches, the target glass compositions were identical. The five SRAT products were prepared for testing in the dry fed melt-rate furnace and the four SME products were prepared for the Slurry-fed Melt-Rate Furnace (SMRF). At the same time, the impacts of washing on a baseline composition from a Chemical Process Cell (CPC) perspective could also be investigated. Five process simulations (0% Na 2 O in frit, 4% Na 2 O in frit, 8% Na 2 O in frit or baseline, 12% Na 2 O in frit, and 16% Na 2 O in frit) were completed in three identical 4-L apparatus to produce the five SRAT products. The SRAT products were later dried and combined with the complementary frits to produce identical glass compositions. All five batches were produced with identical processing steps, including off-gas measurement using online gas chromatographs. Two slurry-fed melter feed batches, a 4% Na 2 O in frit run (less washed sludge combined with
Manufacturing method of enamel substrate for solar cell

Energy Technology Data Exchange (ETDEWEB)

Ono, Jun; Fukamachi, Kazuhiko; Takahashi, Hiroshi

1987-12-01

This invention is an inexpensive manufacturing method of an enamel substrate which improved such defects as crack and stripping, and gives both flatness and pliability of the substrate surface. In other words, in forming a glass layer fritted on at least one surface of a stainless steel strake, frit with the content of SiO/sub 2/ 40-65%, Na/sub 2/O 10-30%, B/sub 2/O/sub 3/ 6-20%, PbO 10-35% is used, wherein SiO/sub 2/ gives flexibility, Na/sub 2/O and B/sub 2/O/sub 3/ increases thermal expansion coefficient, and B/sub 2/O/sub 3/ further endows elastic flexibility to the baked surface. PbO enhances the elasticity of the glass layer. Frit with additional content of K/sub 2/O (2-5%), TiO/sub 2/ (5-8%), CaO (0.5-3.0%) gives further effect. Addition of 1-5 parts of colloidal silica per 100 pts of frit gives an effect with good flatness in spite of thin glass layer. ( 3 tabs )
Bottom-up nanoarchitecture of semiconductor nano-building blocks by controllable in situ SEM-FIB thermal soldering method

KAUST Repository

Zhang, Xuan; Zheng, Xiujun; Zhang, Hong; Zhang, Junli; Fu, Jiecai; Zhang, Qiang; Peng, Chaoyi; Bai, Feiming; Zhang, Xixiang; Peng, Yong

2017-01-01

Here we demonstrate that the building blocks of semiconductor WO3 nanowires can be controllably soldered together by a novel nano-soldering technique of in situ SEM-FIB thermal soldering, in which the soldering temperature can precisely remain in an optimal range to avoid a strong thermal diffusion.
Bottom-up nanoarchitecture of semiconductor nano-building blocks by controllable in situ SEM-FIB thermal soldering method

KAUST Repository

Zhang, Xuan

2017-08-10

Here we demonstrate that the building blocks of semiconductor WO3 nanowires can be controllably soldered together by a novel nano-soldering technique of in situ SEM-FIB thermal soldering, in which the soldering temperature can precisely remain in an optimal range to avoid a strong thermal diffusion.
30 CFR 77.1111 - Welding, cutting, soldering; use of fire extinguisher.

Science.gov (United States)

2010-07-01

... 30 Mineral Resources 1 2010-07-01 2010-07-01 false Welding, cutting, soldering; use of fire... OF UNDERGROUND COAL MINES Fire Protection § 77.1111 Welding, cutting, soldering; use of fire extinguisher. One portable fire extinguisher shall be provided at each location where welding, cutting, or...
Soldered Contact and Current Risetime Effects on Negative Polarity Wire Array Z-pinches

International Nuclear Information System (INIS)

Chalenski, D. A.; Kusse, B. R.; Greenly, J. B.; Blesener, I. C.; McBride, R. D.; Hammer, D. A.; Knapp, P. F.

2009-01-01

The Cornell University COBRA pulser is a nominal 1 MA machine, capable of driving up to 32 wire cylindrical Z-pinch arrays. COBRA can operate with variable current risetimes ranging from 100 ns to 200 ns (short and long pulse, respectively). Wires are typically strung with a ''press'' contact to the electrode hardware, where the wire is loosely pulled against the hardware and held there to establish electrical contact. The machine is normally negative, but a bolt-on convolute can be used to modify the current path and effectively produce positive polarity operation at the load.Previous research with single wires on a 1-5 kA pulser has shown that soldering the wire, thereby improving the wire/electrode contact, and operating in positive polarity can improve the energy deposition into the wire and enhance wire core expansion. Negative polarity showed no difference. Previous experiments on the negative polarity, 20 MA, 100 ns Z accelerator have shown that improving the contact improved the x-ray yield.Cornell data were collected on 16-wire Aluminum Z-pinch arrays in negative polarity. Experiments were conducted with both short and long current pulses with soldered and no-soldered wire/electrode contacts. The initiation, ablation, implosion and stagnation phases were compared for these four conditions. Time dependent x-ray signals were measured using diodes and diamond detectors. An inductive voltage monitor was used to infer minimum current radius achieved, as defined by a uniform shell of current moving radially inward, producing a time dependent inductance. Total energy data were collected with a metal-strip bolometer. Self-emission data were collected by an XUV 4-frame camera and an optical streak camera.In negative polarity and with short pulses, soldering appeared to produce a smaller radius pinch and decrease variations in the x-ray pulse shape. The bolometer, laser backlighter, 4-frame and streak cameras showed negligible differences in the initiation ablation
Fabrication and characterization of MCC approved testing material: ATM-9 glass

International Nuclear Information System (INIS)

Wald, J.W.

1986-06-01

The Materials Characterization Center ATM-9 glass is designed to be representative of glass to be produced by the Defense Waste Processing Facility at the Savannah River Plant, Aiken, South Carolina. ATM-9 glass contains all of the major components of the DWPF glass and corresponds to a waste loading of 29 wt %. The feedstock material for this glass was supplied by Savannah River Laboratory, Aiken, SC, as SRL-165 Black Frit to which was added Ba, Cs, Md, Nd, Zr, as well as 99 Tc, depleted U, 237 Np, 239+240 Pu, and 243 Am. The glass was produced under reducing conditions by the addition of 0.7 wt % graphite during the final melting process. Three kilograms of the glass were produced from April to May of 1984. On final melting, the glass was formed into stress-annealed rectangular bars of two sizes: 1.9 x 1.9 x 10 cm and 1.3 x 1.3 x 10 cm. Seventeen bars of each size were made. The analyzed composition of ATM-9 glass is listed. Examination by optical microscopy of a single transverse section from one bar showed random porosity estimated at 0.36 vol % with nominal pore diameters ranging from approx. 5 μm to 200 μm. Only one distinct second phase was observed and it was at a low concentraction level in the glass matrix. The phase appeared as spherical metallic particles. X-ray diffraction analysis of this same sample did not show any diffraction peaks from crystalline components, indicating that the glass contained less than 5 wt % of crystalline devitrification products. The even shading on the radiograph exposure indicated a generally uniform distribution of radioactivity throughout the glass matrix, with no distinct high-concentration regions
Microstructural evolution and tensile properties of Sn-Ag-Cu mixed with Sn-Pb solder alloys

Energy Technology Data Exchange (ETDEWEB)

Wang Fengjiang [Department of Materials Science and Engineering and Materials Research Center, Missouri University of Science and Technology, Rolla, MO 65401 (United States); O' Keefe, Matthew [Department of Materials Science and Engineering and Materials Research Center, Missouri University of Science and Technology, Rolla, MO 65401 (United States)], E-mail: mjokeefe@mst.edu; Brinkmeyer, Brandon [Department of Materials Science and Engineering and Materials Research Center, Missouri University of Science and Technology, Rolla, MO 65401 (United States)

2009-05-27

The effect of incorporating eutectic Sn-Pb solder with Sn-3.0Ag-0.5Cu (SAC) Pb-free solder on the microstructure and tensile properties of the mixed alloys was investigated. Alloys containing 100, 75, 50, 25, 20, 15, 10, 5 and 0 wt% SAC, with the balance being Sn-37Pb eutectic solder alloy, were prepared and characterized. Optical and scanning electron microscopy were used to analyze the microstructures while 'mini-tensile' test specimens were fabricated and tested to determine mechanical properties at the mm length scale, more closely matching that of the solder joints. Microstructural analysis indicated that a Pb-rich phase formed and was uniformly distributed at the boundary between the Sn-rich grains or between the Sn-rich and the intermetallic compounds in the solder. Tensile results showed that mixing of the alloys resulted in an increase in both the yield and the ultimate tensile strength compared to the original solders, with the 50% SAC-50% Sn-Pb mixture having the highest measured strength. Initial investigations indicate the formation and distribution of a Pb-rich phase in the mixed solder alloys as the source of the strengthening mechanism.
Microstructure characteristics of vacuum glazing brazing joints using laser sealing technique

Science.gov (United States)

Liu, Sixing; Yang, Zheng; Zhang, Jianfeng; Zhang, Shanwen; Miao, Hong; Zhang, Yanjun; Zhang, Qi

2018-05-01

Two pieces of plate glass were brazed into a composite of glazing with a vacuum chamber using PbO-TiO2-SiO2-RxOy powder filler alloys to develop a new type of vacuum glazing. The brazing process was carried out by laser technology. The interface characteristics of laser brazed joints formed between plate glass and solder were investigated using optical microscope, scanning electron microscopy (SEM), energy dispersive spectroscopy (EDS) and X-ray diffraction (XRD) techniques. The results show that the inter-diffusion of Pb/Ti/Si/O elements from the sealing solder toward the glass and O/Al/Si elements from the glass toward the solder, resulting in a reaction layer in the brazed joints. The microstructure phases of PbTiO3, AlSiO, SiO2 and PbO in the glass/solder interface were confirmed by XRD analysis. The joining of the sealing solder to the glass was realized by the reaction products like fibrous structures on interface, where the wetting layer can help improve the bonding performance and strength between the sealing solder and the plate glass during the laser brazing process.

Soluble Lead and Bismuth Chalcogenidometallates: Versatile Solders for Thermoelectric Materials

Energy Technology Data Exchange (ETDEWEB)

Zhang, Hao [Department; Son, Jae Sung [Department; School; Dolzhnikov, Dmitriy S. [Department; Filatov, Alexander S. [Department; Hazarika, Abhijit [Department; Wang, Yuanyuan [Department; Hudson, Margaret H. [Department; Sun, Cheng-Jun [Advanced; Chattopadhyay, Soma [Physical; Talapin, Dmitri V. [Department; Center

2017-07-27

Here we report the syntheses of largely unexplored lead and bismuth chalcogenidometallates in the solution phase. Using N2H4 as the solvent, new compounds such as K6Pb3Te6·7N2H4 were obtained. These soluble molecular compounds underwent cation exchange processes using resin chemistry, replacing Na+ or K+ by decomposable N2H5+ or tetraethylammonium cations. They also transformed into stoichiometric lead and bismuth chalcogenide nanomaterials with the addition of metal salts. Such a versatile chemistry led to a variety of composition-matched solders to join lead and bismuth chalcogenides and tune their charge transport properties at the grain boundaries. Solution-processed thin films composed of Bi0.5Sb1.5Te3 microparticles soldered by (N2H5)6Bi0.5Sb1.5Te6 exhibited thermoelectric power factors (~28 μW/cm K2) comparable to those in vacuum-deposited Bi0.5Sb1.5Te3 films. The soldering effect can also be integrated with attractive fabrication techniques for thermoelectric modules, such as screen printing, suggesting the potential of these solders in the rational design of printable and moldable thermoelectrics.
Thermomechanical fatigue of Sn-37 wt.% Pb model solder joints

International Nuclear Information System (INIS)

Liu, X.W.; Plumbridge, W.J.

2003-01-01

The fatigue of Sn-37 wt.% Pb model solder joints has been investigated under thermomechanical and thermal cycling. Based upon an analysis of displacements during thermomechancial cycling, a model solder joint has been designed to simulate actual joints in electronic packages. The strain-stress relationship, characterised by hysteresis loops, was determined during cycling from 30 to 125 deg. C, and the stress-range monitored throughout. The number of cycles to failure, as defined by the fall in stress range, was correlated to strain range and strain energy. The strain hardening exponent, k, varied with the definition of failure and, when a stress-range drop of 50% was used, it was 0.46. Cracks were produced during pure thermal cycling without external strains applied. These arose due to the local strains caused by thermal expansion mismatches between the solder and Cu 6 Sn 5 intermetallic layer, between the phases of solder, and due to the anisotropy of the materials. The fatigue life under thermomechanical cycling was significantly inferior to that obtained in isothermal mechanical cycling. A factor contributing to this inferiority is the internal damage produced during temperature cycling
Properties and Microstructures of Sn-Ag-Cu-X Lead-Free Solder Joints in Electronic Packaging

OpenAIRE

Sun, Lei; Zhang, Liang

2015-01-01

SnAgCu solder alloys were considered as one of the most popular lead-free solders because of its good reliability and mechanical properties. However, there are also many problems that need to be solved for the SnAgCu solders, such as high melting point and poor wettability. In order to overcome these shortcomings, and further enhance the properties of SnAgCu solders, many researchers choose to add a series of alloying elements (In, Ti, Fe, Zn, Bi, Ni, Sb, Ga, Al, and rare earth) and nanoparti...
Electromigration-induced back stress in critical solder length for three-dimensional integrated circuits

Energy Technology Data Exchange (ETDEWEB)

Huang, Y. T.; Hsu, H. H.; Wu, Albert T., E-mail: atwu@ncu.edu.tw [Department of Chemical and Materials Engineering, National Central University, Jhongli City 320, Taiwan (China)

2014-01-21

Because of the miniaturization of electronic devices, the reliability of electromigration has become a major concern when shrinking the solder dimensions in flip-chip joints. Fast reaction between solders and electrodes causes intermetallic compounds (IMCs) to form, which grow rapidly and occupy entire joints when solder volumes decrease. In this study, U-grooves were fabricated on Si chips as test vehicles. An electrode-solder-electrode sandwich structure was fabricated by using lithography and electroplating. Gaps exhibiting well-defined dimensions were filled with Sn3.5Ag solders. The gaps between the copper electrodes in the test sample were limited to less than 15 μm to simulate microbumps. The samples were stressed at various current densities at 100 °C, 125 °C, and 150 °C. The morphological changes of the IMCs were observed, and the dimensions of the IMCs were measured to determine the kinetic growth of IMCs. Therefore, this study focused on the influence of back stress caused by microstructural evolution in microbumps.
Laser welding of vas deferens in rodents: initial experience with fluid solders.

Science.gov (United States)

Trickett, R I; Wang, D; Maitz, P; Lanzetta, M; Owen, E R

1998-01-01

This study evaluates the use of sutureless laser welding for vasovasostomy. In 14 rodents, the left vas deferens underwent vasovasostomy using an albumin-based solder applied to the adventitia of the vas deferens. The solder contained the dye, indocyanine green, to allow selective absorption and denaturation by a fiber-coupled 800-nm diode laser. The right vas deferens served as a control, receiving conventional layered microsurgical repair. We used a removable 4/0 nylon stent and microclamps to appose the vas deferens during repair, with no need for stay sutures. The mean time to perform laser solder repair (23.5 min) and conventional repair (23.3 min) were not significantly different (P=0.91). However, examination after 8 weeks showed that granuloma formation (G) and patency (P) rates for the conventional suture technique (G, 14%; P, 93%) were significantly better than observed for the laser solder technique (G, 57%; P, 50%).
Laser beam soldering of micro-optical components

Science.gov (United States)

Eberhardt, R.

2003-05-01

MOTIVATION Ongoing miniaturisation and higher requirements within optical assemblies and the processing of temperature sensitive components demands for innovative selective joining techniques. So far adhesive bonding has primarily been used to assemble and adjust hybrid micro optical systems. However, the properties of the organic polymers used for the adhesives limit the application of these systems. In fields of telecommunication and lithography, an enhancement of existing joining techniques is necessary to improve properties like humidity resistance, laserstability, UV-stability, thermal cycle reliability and life time reliability. Against this background laser beam soldering of optical components is a reasonable joining technology alternative. Properties like: - time and area restricted energy input - energy input can be controlled by the process temperature - direct and indirect heating of the components is possible - no mechanical contact between joining tool and components give good conditions to meet the requirements on a joining technology for sensitive optical components. Additionally to the laser soldering head, for the assembly of optical components it is necessary to include positioning units to adjust the position of the components with high accuracy before joining. Furthermore, suitable measurement methods to characterize the soldered assemblies (for instance in terms of position tolerances) need to be developed.
Comparison of implant-abutment interface misfits after casting and soldering procedures.

Science.gov (United States)

Neves, Flávio Domingues das; Elias, Gisele Araújo; da Silva-Neto, João Paulo; de Medeiros Dantas, Lucas Costa; da Mota, Adérito Soares; Neto, Alfredo Júlio Fernandes

2014-04-01

The aim of this study was to compare vertical and horizontal adjustments of castable abutments after conducting casting and soldering procedures. Twelve external hexagonal implants (3.75 × 10 mm) and their UCLA abutments were divided according their manufacturer and abutment type: PUN (plastic UCLA, Neodent), PUC (plastic UCLA, Conexão), PU3i (plastic UCLA, Biomet 3i), and PUTN (plastic UCLA with Tilite milled base, Neodent). Three infrastructures of a fixed partial implant-supported bridge with 3 elements were produced for each group. The measurements of vertical (VM) and horizontal (HM) misfits were obtained via scanning electron microscopy after completion of casting and soldering. The corresponding values were determined to be biomechanically acceptable to the system, and the results were rated as a percentage. Statistical analysis establishes differences between groups by chi-square after procedures, and McNeman's test was applied to analyze the influence of soldering over casting (α ≤ .05). For the values of VM and HM, respectively, when the casting process was complete, it was observed that 83.25% and 100% (PUTN), 33.3% and 27.75% (PUN), 33.3% and 88.8% (PUC), 33.3% and 94.35% (PU3i) represented acceptable values. After completing the requisite soldering, acceptable values were 50% and 94.35% (PUTN), 16.6% and 77.7% (PUN), 38.55% and 77.7% (PUC), and 27.75% and 94.35% (PU3i). Within the limitations of this study, it can be concluded that the premachined abutments presented more acceptable VM values. The HM values were within acceptable limits before and after the soldering procedure for most groups. Further, the soldering procedure resulted in an increase of VM in all groups.
Characterizing performances of solder paste printing process at flexible manufacturing lines

International Nuclear Information System (INIS)

Siew, Jit Ping; Low, Heng Chin; Teoh, Ping Chow

2015-01-01

Solder paste printing (SPP) has been a challenge on printed circuit board (PCB) manufacturing, evident by the proliferation of solder paste inspection equipment, or substituted by rigorous non-value added activity of manual inspections. The objective of this study is to characterize the SPP performance of various products manufactured in flexible production lines with different equipment configurations, and determine areas for process improvement. The study began by collecting information on SPP performance relative to component placement (CP) process, and to the proportion of mixed products. Using a clustering algorithm to group similar elements together, SPP performance across all product-production line pairs are statistically modeled to discover the trend and the influential factors. The main findings are: (a) Ratio of overall dpku for CP and SPP processes are 2:1; (b) logistic regression models of SPP performance indicated that only effects of product-production line and solder paste printer configuration are significant; (c) PCB circuitry design with BGA components and single solder paste printer line configurations generated the highest monthly defects, with the highest variation in the latter
Characterizing performances of solder paste printing process at flexible manufacturing lines

Energy Technology Data Exchange (ETDEWEB)

Siew, Jit Ping; Low, Heng Chin [University of Science Malaysia, 11800 Minden, Penang (Malaysia); Teoh, Ping Chow [Wawasan Open University, 54 Jalan Sultan Ahmad Shah, 10050 Penang (Malaysia)

2015-02-03

Solder paste printing (SPP) has been a challenge on printed circuit board (PCB) manufacturing, evident by the proliferation of solder paste inspection equipment, or substituted by rigorous non-value added activity of manual inspections. The objective of this study is to characterize the SPP performance of various products manufactured in flexible production lines with different equipment configurations, and determine areas for process improvement. The study began by collecting information on SPP performance relative to component placement (CP) process, and to the proportion of mixed products. Using a clustering algorithm to group similar elements together, SPP performance across all product-production line pairs are statistically modeled to discover the trend and the influential factors. The main findings are: (a) Ratio of overall dpku for CP and SPP processes are 2:1; (b) logistic regression models of SPP performance indicated that only effects of product-production line and solder paste printer configuration are significant; (c) PCB circuitry design with BGA components and single solder paste printer line configurations generated the highest monthly defects, with the highest variation in the latter.
Mechanical Deformation Behavior of Sn-Ag-Cu Solders with Minor Addition of 0.05 wt.% Ni

Science.gov (United States)

Hammad, A. E.; El-Taher, A. M.

2014-11-01

The aim of the present work is to develop a comparative evaluation of the microstructural and mechanical deformation behavior of Sn-Ag-Cu (SAC) solders with the minor addition of 0.05 wt.% Ni. Test results showed that, by adding 0.05Ni element into SAC solders, generated mainly small rod-shaped (Cu,Ni)6Sn5 intermetallic compounds (IMCs) inside the β-Sn phase. Moreover, increasing the Ag content and adding Ni could result in the change of the shape and size of the IMC precipitate. Hence, a significant improvement is observed in the mechanical properties of SAC solders with increasing Ag content and Ni addition. On the other hand, the tensile results of Ni-doped SAC solders showed that both the yield stress and ultimate tensile strengths decrease with increasing temperature and with decreasing strain rate. This behavior was attributed to the competing effects of work hardening and dynamic recovery processes. The Sn-2.0Ag-0.5Cu-0.05Ni solder displayed the highest mechanical properties due to the formation of hard (Cu,Ni)6Sn5 IMCs. Based on the obtained stress exponents and activation energies, it is suggested that the dominant deformation mechanism in SAC (205)-, SAC (0505)- and SAC (0505)-0.05Ni solders is pipe diffusion, and lattice self-diffusion in SAC (205)-0.05Ni solder. In view of these results, the Sn-2.0Ag-0.5Cu-0.05Ni alloy is a more reliable solder alloy with improved properties compared with other solder alloys tested in the present work.
Al and Si Alloying Effect on Solder Joint Reliability in Sn-0.5Cu for Automotive Electronics

Science.gov (United States)

Hong, Won Sik; Oh, Chulmin; Kim, Mi-Song; Lee, Young Woo; Kim, Hui Joong; Hong, Sung Jae; Moon, Jeong Tak

2016-12-01

To suppress the bonding strength degradation of solder joints in automotive electronics, we proposed a mid-temperature quaternary Pb-free Sn-0.5Cu solder alloy with minor Pd, Al, Si and Ge alloying elements. We manufactured powders and solder pastes of Sn-0.5Cu-(0.01,0.03)Al-0.005Si-(0.006-0.007)Ge alloys ( T m = 230°C), and vehicle electronic control units used for a flame-retardant-4 printed circuit board with an organic solderability preservative finish were assembled by a reflow soldering process. To investigate the degradation properties of solder joints used in engine compartments, thermal cycling tests were conducted from -40°C to 125°C (10 min dwell) for 1500 cycles. We also measured the shear strength of the solder joints in various components and observed the microstructural evolution of the solder joints. Based on these results, intermetallic compound (IMC) growth at the solder joints was suppressed by minor Pd, Al and Si additions to the Sn-0.5Cu alloy. After 1500 thermal cycles, IMC layers thicknesses for 100 parts per million (ppm) and 300 ppm Al alloy additions were 6.7 μm and 10 μm, compared to the as-reflowed bonding thicknesses of 6 μm and 7 μm, respectively. Furthermore, shear strength degradation rates for 100 ppm and 300 ppm Al(Si) alloy additions were at least 19.5%-26.2%. The cause of the improvement in thermal cycling reliability was analyzed using the (Al,Cu)-Sn, Si-Sn and Al-Sn phases dispersed around the Cu6Sn5 intermetallic at the solder matrix and bonding interfaces. From these results, we propose the possibility of a mid-temperature Sn-0.5Cu(Pd)-Al(Si)-Ge Pb-free solder for automotive engine compartment electronics.
Long-Term Effects of Soldering By-Products on Nickel-Coated Copper Wire

Science.gov (United States)

Rolin, T. D.; Hodge, R. E.

2008-01-01

An analysis of thirty-year-old, down graded flight cables was conducted to determine the makeup of a green material on the surface of the shielded wire near soldered areas and to ascertain if the green material had corroded the nickel-coated copper wire. Two likely candidates were possible due to the handling and environments to which these cables were exposed. The flux used to solder the cables is known to contain abietic acid, a carboxylic acid found in many pine rosins used for the soldering process. The resulting material copper abietate is green in color and is formed during the application of heat during soldering operations. Copper (II) chloride, which is also green in color is known to contaminate flight parts and is corrosive. Data is presented that shows the material is copper abietate, not copper (II) chloride, and more importantly that the abietate does not aggressively attack nickel-plated copper wire.
A Probabilistic Approach to Predict Thermal Fatigue Life for Ball Grid Array Solder Joints

Science.gov (United States)

Wei, Helin; Wang, Kuisheng

2011-11-01

Numerous studies of the reliability of solder joints have been performed. Most life prediction models are limited to a deterministic approach. However, manufacturing induces uncertainty in the geometry parameters of solder joints, and the environmental temperature varies widely due to end-user diversity, creating uncertainties in the reliability of solder joints. In this study, a methodology for accounting for variation in the lifetime prediction for lead-free solder joints of ball grid array packages (PBGA) is demonstrated. The key aspects of the solder joint parameters and the cyclic temperature range related to reliability are involved. Probabilistic solutions of the inelastic strain range and thermal fatigue life based on the Engelmaier model are developed to determine the probability of solder joint failure. The results indicate that the standard deviation increases significantly when more random variations are involved. Using the probabilistic method, the influence of each variable on the thermal fatigue life is quantified. This information can be used to optimize product design and process validation acceptance criteria. The probabilistic approach creates the opportunity to identify the root causes of failed samples from product fatigue tests and field returns. The method can be applied to better understand how variation affects parameters of interest in an electronic package design with area array interconnections.
Leaching Tc-99 from SRP glass in simulated tuff and salt groundwaters

International Nuclear Information System (INIS)

Bibler, N.E.; Jurgensen, A.R.

1987-01-01

Results of leach tests with Tc-99 doped SRP borosilicate waste glass are presented. The glass was prepared by melting a mixture of SRP 165 powdered frit doped with a carrier free solution of Tc-99 at 1150 0 C. Dissolution of portions of the resulting glass indicated that the Tc-99 was distributed homogeneously throughout the glass. Static leach tests up to 90 days were performed at 90 0 C in J-13 tuff groundwater or WIPP brine A at a SA/V of 100m -1 . Normalized mass losses were calculated for Tc-99 as well as all the major elements in the glass. Results indicated that under ambient oxidizing conditions Tc-99 leached no faster than the glass-forming elements of the glass. In J-13 water, Tc-99 leached congruently with B. In WIPP brine A, it leached congruently with Si. Leach rates for Li were higher in both groundwaters, probably due to a contribution from an ion exchange mechanism. Leach tests were performed under reducing conditions in J-13 water by adding Zn/Hg amalgam to the leachate. In these tests the pH increased significantly, probably because of the reaction of the amalgam with the water. In a 21-day test, the pH increased to 13 and leach rates for the glass were very high. Even though there was signifcant dissolution of the glass, the normalized mass loss based on Tc-99 was only 0.02g/m 2 . This result and the fact that reducing conditions at normal pH values do not significantly affect the dissolution of the glass, indicate that the low concentrations for Tc-99 obtained under reducing conditions are due to is solubility and not due to an increased durability of the glass. 14 refs., 2 figs., 5 tabs
Microanalysis of tool steel and glass with laser-induced breakdown spectroscopy

Science.gov (United States)

Loebe, Klaus; Uhl, Arnold; Lucht, Hartmut

2003-10-01

A laser microscope system for the microanalytical characterization of complex materials is described. The universal measuring principle of laser-induced breakdown spectroscopy (LIBS) in combination with echelle optics permits a fast simultaneous multielement analysis with a possible spatial resolution below 10 pm. The developed system features completely UV-transparent optics for the laser-microscope coupling and the emission beam path and enables parallel signal detection within the wavelength range of 200-800 nm with a spectral resolution of a few picometers. Investigations of glass defects and tool steels were performed. The characterization of a glass defect in a tumbler by a micro-LIBS line scan, with use of a 266-nm diode-pumped Nd:YAG laser for excitation, is possible by simple comparison of plasma spectra of the defect and the surrounding area. Variations in the main elemental composition as well as impurities by trace elements are detected at the same time. Through measurement of the calibration samples with the known concentration of the corresponding element, a correlation between the intensity of spectral lines and the element concentration was also achieved. The change of elemental composition at the transient stellite solder of tool steels has been determined by an area scan. The two-dimensional pictures show abrupt changes of the element distribution along the solder edge and allow fundamental researches of dynamic modifications (e.g., diffusion) in steel.
How Many Peripheral Solder Joints in a Surface Mounted Design Experience Inelastic Strains?

Science.gov (United States)

Suhir, E.; Yi, S.; Ghaffarian, R.

2017-03-01

It has been established that it is the peripheral solder joints that are the most vulnerable in the ball-grid-array (BGA) and column-grid-array (CGA) designs and most often fail. As far as the long-term reliability of a soldered microelectronics assembly as a whole is concerned, it makes a difference, if just one or more peripheral joints experience inelastic strains. It is clear that the low cycle fatigue lifetime of the solder system is inversely proportional to the number of joints that simultaneously experience inelastic strains. A simple and physically meaningful analytical expression (formula) is obtained for the prediction, at the design stage, of the number of such joints, if any, for the given effective thermal expansion (contraction) mismatch of the package and PCB; materials and geometrical characteristics of the package/PCB assembly; package size; and, of course, the level of the yield stress in the solder material. The suggested formula can be used to determine if the inelastic strains in the solder material could be avoided by the proper selection of the above characteristics and, if not, how many peripheral joints are expected to simultaneously experience inelastic strains. The general concept is illustrated by a numerical example carried out for a typical BGA package. The suggested analytical model (formula) is applicable to any soldered microelectronics assembly. The roles of other important factors, such as, e.g., solder material anisotropy, grain size, and their random orientation within a joint, are viewed in this analysis as less important factors than the level of the interfacial stress. The roles of these factors will be accounted for in future work and considered, in addition to the location of the joint, in a more complicated, more sophisticated, and more comprehensive reliability/fatigue model.
Development of Bi-base high-temperature Pb-free solders with second-phase dispersion: Thermodynamic calculation, microstructure, and interfacial reaction

Science.gov (United States)

Takaku, Yoshikazu; Ohnuma, Ikuo; Kainuma, Ryosuke; Yamada, Yasushi; Yagi, Yuji; Nishibe, Yuji; Ishida, Kiyohito

2006-11-01

Bismuth and its alloys are candidates for Pb-free high-temperature solders that can be substituted for conventional Pb-rich Pb-Sn solders (melting point (mp) = 573 583 K). However, inferior properties such as brittleness and weak bonding strength should be improved for practical use. To that end, BiCu-X (X=Sb, Sn, and Zn) Pb-free high-temperature solders are proposed. Miscibility gaps in liquid BiCu-X alloys were surveyed using the thermodynamic database ADAMIS (alloy database for micro-solders), and compositions of the BiCu-X solders were designed on the basis of calculation. In-situ composite solders that consist of a Bi-base matrix with fine intermetallic compound (IMC) particles were produced by gas-atomizing and melt-spinning methods. The interfacial reaction between in-situ composite solders and Cu or Ni substrates was investigated. The IMCs at the interface formed a thin, uniform layer, which is an appropriate morphology for a reliable solder joint.
Corrosion Behaviour of Sn-based Lead-Free Solders in Acidic Solution

Science.gov (United States)

Nordarina, J.; Mohd, H. Z.; Ahmad, A. M.; Muhammad, F. M. N.

2018-03-01

The corrosion properties of Sn-9(5Al-Zn), Sn-Cu and SAC305 were studied via potentiodynamic polarization method in an acidic solution of 1 M hydrochloric acid (HCl). Sn-9(5Al-Zn) produced different polarization profile compared with Sn-Cu and SAC305. The morphological analysis showed that small, deep grooves shaped of corrosion product formed on top of Sn-9(5Al-Zn) solder while two distinctive structures of closely packed and loosely packed corrosion product formed on top of Sn-Cu and SAC305 solder alloys. Phase analysis revealed the formations of various corrosion products such as SnO and SnO2 mainly dominant on surface of solder alloys after potentiodynamic polarization in 1 M hydrochloric acid (HCl).
Effect of Multiple Reflow Cycles and Al2O3 Nanoparticles Reinforcement on Performance of SAC305 Lead-Free Solder Alloy

Science.gov (United States)

Tikale, Sanjay; Prabhu, K. Narayan

2018-05-01

The effect of Al2O3 nanoparticles reinforcement on melting behavior, microstructure evolution at the interface and joint shear strength of 96.5Sn3Ag0.5Cu (SAC305) lead-free solder alloy subjected to multiple reflow cycles was investigated. The reinforced SAC305 solder alloy compositions were prepared by adding Al2O3 nanoparticles in different weight fractions (0.05, 0.1, 0.3 and 0.5 wt.%) through mechanical dispersion. Cu/solder/Cu micro-lap-shear solder joint specimens were used to assess the shear strength of the solder joint. Differential scanning calorimetry was used to investigate the melting behavior of SAC305 solder nanocomposites. The solder joint interfacial microstructure was studied using scanning electron microscopy. The results showed that the increase in melting temperature (T L) and melting temperature range of the SAC305 solder alloy by addition of Al2O3 nanoparticles were not significant. In comparison with unreinforced SAC305 solder alloy, the reinforcement of 0.05-0.5 wt.% of Al2O3 nanoparticles improved the solder wettability. The addition of nanoparticles in minor quantity effectively suppressed the Cu6Sn5 IMC growth, improved the solder joint shear strength and ductility under multiple reflow cycles. However, the improvement in solder properties was less pronounced on increasing the nanoparticle content above 0.1 wt.% of the solder alloy.
Microstructural discovery of Al addition on Sn–0.5Cu-based Pb-free solder design

International Nuclear Information System (INIS)

Koo, Jahyun; Lee, Changsoo; Hong, Sung Jea; Kim, Keun-Soo; Lee, Hyuck Mo

2015-01-01

It is important to develop Pb-free solder alloys suitable for automotive use instead of traditional Sn–Pb solder due to environmental regulations (e.g., Restriction of Hazardous Substances (RoHS)). Al addition has been spotlighted to enhance solder properties. In this study, we investigated the microstructural change of Sn–0.5Cu wt.% based Pb-free solder alloys with Al addition (0.01–0.05 wt.%). The small amount of Al addition caused a remarkable microstructural change. The Al was favored to form Cu–Al intermetallic compounds inside the solder matrix. We identified the Cu–Al intermetallic compound as Cu_3_3Al_1_7, which has a rhombohedral structure, using EPMA and TEM analyses. This resulted in refined Cu_6Sn_5 networks in the Sn–0.5Cu based solder alloy. In addition, we conducted thermal analysis to confirm its stability at a high temperature of approximately 230 °C, which is the necessary temperature range for automotive applications. The solidification results were substantiated thermodynamically using the Scheil solidification model. We can provide criteria for the minimum aluminum content to modify the microstructure of Pb-free solder alloys. - Graphical abstract: The minor Al additions refined eutectic Cu_6Sn_5 IMC networks on the Sn–0.5Cu based solder alloys. The microstructure was dramatically changed with the minor Al addition. - Highlights: • We observed dramatic microstructure-change with Al additions. • We defined Cu_3_3Al_1_7 IMC with Al additions using TEM analysis. • We investigated grain refinement with Al additions using EBSD. • We discussed the refinement based on Scheil solidification model.

Microstructural discovery of Al addition on Sn–0.5Cu-based Pb-free solder design

Energy Technology Data Exchange (ETDEWEB)

Koo, Jahyun; Lee, Changsoo [Department of Materials Science and Engineering, KAIST, Daejeon 305-701 (Korea, Republic of); Hong, Sung Jea [MK Electron Co., Ltd., Yongin Cheoin-gu 316-2 (Korea, Republic of); Kim, Keun-Soo, E-mail: keunsookim@hoseo.edu [Department of Display Engineering, Hoseo University, Asan 336-795 (Korea, Republic of); Lee, Hyuck Mo, E-mail: hmlee@kaist.ac.kr [Department of Materials Science and Engineering, KAIST, Daejeon 305-701 (Korea, Republic of)

2015-11-25

It is important to develop Pb-free solder alloys suitable for automotive use instead of traditional Sn–Pb solder due to environmental regulations (e.g., Restriction of Hazardous Substances (RoHS)). Al addition has been spotlighted to enhance solder properties. In this study, we investigated the microstructural change of Sn–0.5Cu wt.% based Pb-free solder alloys with Al addition (0.01–0.05 wt.%). The small amount of Al addition caused a remarkable microstructural change. The Al was favored to form Cu–Al intermetallic compounds inside the solder matrix. We identified the Cu–Al intermetallic compound as Cu{sub 33}Al{sub 17}, which has a rhombohedral structure, using EPMA and TEM analyses. This resulted in refined Cu{sub 6}Sn{sub 5} networks in the Sn–0.5Cu based solder alloy. In addition, we conducted thermal analysis to confirm its stability at a high temperature of approximately 230 °C, which is the necessary temperature range for automotive applications. The solidification results were substantiated thermodynamically using the Scheil solidification model. We can provide criteria for the minimum aluminum content to modify the microstructure of Pb-free solder alloys. - Graphical abstract: The minor Al additions refined eutectic Cu{sub 6}Sn{sub 5} IMC networks on the Sn–0.5Cu based solder alloys. The microstructure was dramatically changed with the minor Al addition. - Highlights: • We observed dramatic microstructure-change with Al additions. • We defined Cu{sub 33}Al{sub 17} IMC with Al additions using TEM analysis. • We investigated grain refinement with Al additions using EBSD. • We discussed the refinement based on Scheil solidification model.
Investigation of moisture uptake into printed circuit board laminate and solder mask materials

DEFF Research Database (Denmark)

Conseil, Helene; Gudla, Visweswara Chakravarthy; Borgaonkar, Shruti

2017-01-01

with different solder mask materials and exposed to saturated water vapour and liquid water. The solder masks are characterised for their microstructure and constituent phases using scanning electron microscopy and X-ray diffraction. The observations are correlated with themoisture absorption characteristic...
Laser-tissue soldering with biodegradable polymer films in vitro: film surface morphology and hydration effects.

Science.gov (United States)

Sorg, B S; Welch, A J

2001-01-01

Previous research introduced the concept of using biodegradable polymer film reinforcement of a liquid albumin solder for improvement of the tensile strength of repaired incisions in vitro. In this study, the effect of creating small pores in the PLGA films on the weld breaking strength is studied. Additionally, the effect of hydration on the strength of the reinforced welds is investigated. A 50%(w/v) bovine serum albumin solder with 0.5 mg/mL Indocyanine Green dye was used to repair an incision in bovine aorta. The solder was coagulated with an 806-nm CW diode laser. A poly(DL-lactic-co-glycolic acid) (PLGA) film was used to reinforce the solder (the controls had solder but no reinforcement). Breaking strengths were measured acutely and after hydration in saline for 1 and 2 days. The data were analyzed by ANOVA (P < 0.05) and multiple comparisons of means were performed using the Newman-Keuls test. The creation of pores in the PLGA films qualitatively improved the film flexibility without having an apparent adverse effect on the breaking strength, while the actual technique of applying the film and solder had more of an effect. The acute maximum average breaking strengths of some of the film reinforced specimens (114.7 g-134.4 g) were significantly higher (P < 0.05) than the acute maximum average breaking strength of the unreinforced control specimens (68.3 g). Film reinforced specimens were shown to have a statistically significantly higher breaking strength than unreinforced controls after 1- and 2-day hydration. Reinforcement of liquid albumin solders in laser-assisted incision repair appears to have advantages over conventional methods that do not reinforce the cohesive strength of the solder in terms of acute breaking strength and after immersion in moist environments for short periods of time. Using a film with the solder applied to one surface only may be advantageous over other techniques.
Investigation Of The Effects Of Reflow Profile Parameters On Lead-free Solder Bump Volumes And Joint Integrity

Science.gov (United States)

Amalu, E. H.; Lui, Y. T.; Ekere, N. N.; Bhatti, R. S.; Takyi, G.

2011-01-01

The electronics manufacturing industry was quick to adopt and use the Surface Mount Technology (SMT) assembly technique on realization of its huge potentials in achieving smaller, lighter and low cost product implementations. Increasing global customer demand for miniaturized electronic products is a key driver in the design, development and wide application of high-density area array package format. Electronic components and their associated solder joints have reduced in size as the miniaturization trend in packaging continues to be challenged by printing through very small stencil apertures required for fine pitch flip-chip applications. At very narrow aperture sizes, solder paste rheology becomes crucial for consistent paste withdrawal. The deposition of consistent volume of solder from pad-to-pad is fundamental to minimizing surface mount assembly defects. This study investigates the relationship between volume of solder paste deposit (VSPD) and the volume of solder bump formed (VSBF) after reflow, and the effect of reflow profile parameters on lead-free solder bump formation and the associated solder joint integrity. The study uses a fractional factorial design (FFD) of 24-1 Ramp-Soak-Spike reflow profile, with all main effects and two-way interactions estimable to determine the optimal factorial combination. The results from the study show that the percentage change in the VSPD depends on the combination of the process parameters and reliability issues could become critical as the size of solder joints soldered on the same board assembly vary greatly. Mathematical models describe the relationships among VSPD, VSBF and theoretical volume of solder paste. Some factors have main effects across the volumes and a number of interactions exist among them. These results would be useful for R&D personnel in designing and implementing newer applications with finer-pitch interconnect.
Wall-slip effects in SnAgCu solder pastes used in electronics assembly applications

International Nuclear Information System (INIS)

Mallik, S.; Ekere, N.N.; Durairaj, R.; Marks, A.E.; Seman, A.

2009-01-01

Solder paste is the most important strategic bonding material used in the assembly of surface mount components in electronics manufacturing. As the trend towards miniaturisation of electronic products continues, there is an increasing demand for better understanding of the flow and deformation that is, the rheological behaviour of solder paste formulations. Wall slip plays an important role in characterising the flow behaviour of solder paste materials. The problem of wall slip arises due to the various attractive and repulsive forces acting between the solder particles and the walls of the measuring geometry. These interactions could lead to the presence of a thin solvent layer adjacent to the wall, which gives rise to slippage. In rheological measurements, slip effects can generally be avoided by using roughened surfaces for measuring geometries. In this paper, a novel technique is developed to study the effect of wall slip in the rheological measurements of lead-free solder paste. The viscosity and oscillatory data obtained for three different solder paste samples (from measuring geometries of different surface roughness) have been analysed and compared. In viscosity measurements, slip effects were dominant at low shear rates and the use of serrated surfaces was found to be quite effective in minimizing slip effects. Oscillatory measurements were also affected by roughening the surfaces of measuring geometries.
Investigation on solder joint strength of nickel tin-plated and CRS tabs with PCB

International Nuclear Information System (INIS)

Luay Hussain

2002-01-01

Failure analysis on easily peels off Nickel and CRS steel tabs from PCB was carried out. Nickel Tin plated tabs, CRS steel tabs and tube were joined to the PCB using reflow/ convection soldering, in an oven. The solder paste composition is Sn36/Pb35/Ag2. Peel test was conducted and it was found that many tabs could be easily peeled off with low force. Porosities which varies from 0.4 mm to < 0.01mm in diameter, developed during soldering process and solidification was noted. It was found, the number, size and position of these porosities inside the solder layer on both parts of the tabs affect the peel strength. Scanning Electron Microscopy study and EDX analysis were carried out. It was found that the low peel strength values were due to the combination of generation and development of porosities during soldering process which act as stress concentrators and the evolution (growth) of eutectic Sn/Pb and Sn/Ni/Cu brittle grainy phase. Large eutectic microstructure with brittle Sn-Ni-Cu grainy phase enhances the failure with low peeling forces. Sample showing no feature of Sn/Ni/Cu grain gave high peeling strength value. Solder reflow, an important process, can result in strength enhancement (if it was controlled for example in a furnace). (Author)
High-level waste processing at the Savannah River Site: An update

International Nuclear Information System (INIS)

Marra, J.E.; Bennett, W.M.; Elder, H.H.; Lee, E.D.; Marra, S.L.; Rutland, P.L.

1997-01-01

The Defense Waste Processing Facility (DWPF) at the Savannah River Site (SRS) in Aiken, SC mg began immobilizing high-level radioactive waste in borosilicate glass in 1996. Currently, the radioactive glass is being produced as a ''sludge-only'' composition by combining washed high-level waste sludge with glass frit. The glass is poured in stainless steel canisters which will eventually be disposed of in a permanent, geological repository. To date, DWPF has produced about 100 canisters of vitrified waste. Future processing operations will, be based on a ''coupled'' feed of washed high-level waste sludge, precipitated cesium, and glass frit. This paper provides an update of the processing activities completed to date, operational/flowsheet problems encountered, and programs underway to increase production rates
Thermal decomposition of solder flux activators under simulated wave soldering conditions

DEFF Research Database (Denmark)

Piotrowska, Kamila; Jellesen, Morten Stendahl; Ambat, Rajan

2017-01-01

/methodology/approach: Changes in the chemical structure of the activators were studied using Fourier transform infrared spectroscopy technique and were correlated to the exposure temperatures within the range of wave soldering process. The amount of residue left on the surface was estimated using standardized acid-base...... titration method as a function of temperature, time of exposure and the substrate material used. Findings: The study shows that there is a possibility of anhydride-like species formation during the thermal treatment of fluxes containing weak organic acids (WOAs) as activators (succinic and DL...
Development of high melting point, environmentally friendly solders, using the calphad approach

DEFF Research Database (Denmark)

Chidambaram, Vivek; Hald, John; Hattel, Jesper Henri

2008-01-01

An attempt has been made using the CALPHAD approach via Thermo-Calc to explore the various possible chemical compositions that adhere to the melting criterion i.e. 270-350 degrees C, required to replace the traditionally used high lead content solders for first level packaging applications. Vario...... tension have also been considered. Special focus has been given to toxicity related issues since the main ideology of looking for an alternative to high lead containing solders is not related to technical issues but due to environmental concerns.......An attempt has been made using the CALPHAD approach via Thermo-Calc to explore the various possible chemical compositions that adhere to the melting criterion i.e. 270-350 degrees C, required to replace the traditionally used high lead content solders for first level packaging applications. Various...... of promising solder alloy candidates. The ternary combinations that satisfied the primary solidification requirement were scrutinized taking into account the commercial interests i.e. availability, cost-effectiveness, recyclability and toxicity issues. Technical issues like manufacturability and surface...
Reliability of soldered joints for automotive electronic devices; Denso buhin ni okeru handa setsugo no shinraisei

Energy Technology Data Exchange (ETDEWEB)

Kita, T; Mukaibo, N; Ando, K; Moriyama, M [Honda R and D Co. Ltd., Tokyo (Japan)

1997-10-01

Concerning the tin and lead eutectic solder, we have evaluated the reliability of three factors of intermetallic compound layer, creep and vibration which cause solder degradation. First, the stress factor was extracted from investigating the mechanism of degradation, and the best acceleration test method was fixed. Next, the acceleration test was executed to find the stress dependency and the tendency of solder degradation was modeled numerically. While the environmental stress frequency was obtained and they were put together by using a minor method, which enabled us to predict the life span of solder on the market with precision. 5 refs., 13 figs.
Finite Element-Assisted Assessment of the Thermo-cyclic Characteristics of Leads Soldered with SnAgCu(+Bi,In) Alloys

Science.gov (United States)

Lis, Adrian; Nakanishi, Kohei; Matsuda, Tomoki; Sano, Tomokazu; Minagawa, Madoka; Okamoto, Masahide; Hirose, Akio

2017-07-01

Solder joints between leads and printed circuit boards in thin small outline packages were produced with conventional Sn1.0Ag0.7Cu (SAC107) and Sn3.0Ag0.7Cu (SAC305) solders as well as various solder alloys with gradually increasing amounts of Bi (up to 3.0 wt.%) and In (up to 1.0 wt.%) within the SAC107 base solder. The reliability of soldered leads in temperature cycle (TC) tests improved most with solder alloys containing both Bi (1.6 wt.%) and In (0.5 wt.%). Microindentation and electron probe microanalysis mappings revealed that the effect originates from a combination of solution and precipitation strengthening of the initial SAC alloy. The distribution of inelastic strain accumulation (ISA), as a measure for degradation, was determined in the solder joints by finite element calculations. It was shown that defects in the solder proximal to the lead (60-75 μm), which was underpinned by similar cracking characteristics along the lead-solder interface. The ISA was confirmed to be lower in SAC+Bi/In alloys owing to their enhanced elasto-plastic properties. Moreover, the addition of a thin Cu coating on the leads could improve the joint reliability, as suggested by the calculation of the ISA and the acceleration factor.
Comparison of fine particle colemanite and boron frit in concrete for time-strength relationship

International Nuclear Information System (INIS)

Volkman, D.E.; Bussolini, P.L.

1992-01-01

This paper reports that the element boron, when added to concrete, has proved effective in shielding neutron particles by absorbing the neutron and emitting a low-energy gamma ray. The various boron additives used with concrete can severely retard the set time and strength gain. An advantage to using small particle size boron is that the smaller grain size provides better boron disbursement within the concrete matrix to absorb neutrons. However, boron additives of powder consistency are usually not used due to the greater potential of forming chemical solutions that act as a retarder in the concrete. Research has shown that the amount of boron additives in concrete can be reduced significantly if fine grain particles can be successfully incorporated into the concrete matrix. The purpose of this study is to compare strength gain characteristics of concrete mixes containing various quantities of fine grain boron additive. The boron additive colemanite, a natural mineral, is compared with two brands of manufactured aggregate, boron frit. Concrete test cylinders are molded for testing the compressive strength of the mix after 4, 7, 28, and 56 days. Tested are five different quantities of colemanite as well as five comparable amounts of boron frit for each brand of the material. The test values are compared with a control concrete specimen containing no boron additive. Results of this study can be used to optimize the cost and effectiveness of boron additives in radiation shielding concrete
In-situ study of electromigration-induced grain rotation in Pb-free solder joint by synchrotron microdiffraction

International Nuclear Information System (INIS)

Chen, Kai; Tamura, Nobumichi; Tu, King-Ning

2008-01-01

The rotation of Sn grains in Pb-free flip chip solder joints hasn't been reported in literature so far although it has been observed in Sn strips. In this letter, we report the detailed study of the grain orientation evolution induced by electromigration by synchrotron based white beam X-ray microdiffraction. It is found that the grains in solder joint rotate more slowly than in Sn strip even under higher current density. On the other hand, based on our estimation, the reorientation of the grains in solder joints also results in the reduction of electric resistivity, similar to the case of Sn strip. We will also discuss the reason why the electric resistance decreases much more in strips than in the Sn-based solders, and the different driving force for the grain growth in solder joint and in thin film interconnect lines
Subgrain Rotation Behavior in Sn3.0Ag0.5Cu-Sn37Pb Solder Joints During Thermal Shock

Science.gov (United States)

Han, Jing; Tan, Shihai; Guo, Fu

2018-01-01

Ball grid array (BGA) samples were soldered on a printed circuit board with Sn37Pb solder paste to investigate the recrystallization induced by subgrain rotation during thermal shock. The composition of the solder balls was Sn3.0Ag0.5Cu-Sn37Pb, which comprised mixed solder joints. The BGA component was cross-sectioned before thermal shock. The microstructure and grain orientations were obtained by a scanning electron microscope equipped with an electron back-scattered diffraction system. Two mixed solder joints at corners of the BGA component were selected as the subjects. The results showed that recrystallization occurred at the corner of the solder joints after 200 thermal shock cycles. The recrystallized subgrains had various new grain orientations. The newly generated grain orientations were closely related to the initial grain orientations, which indicated that different subgrain rotation behaviors could occur in one mixed solder joint with the same initial grain orientation. When the misorientation angles were very small, the rotation axes were about Sn [100], [010] and [001], as shown by analyzing the misorientation angles and subgrain rotation axes, while the subgrain rotation behavior with large misorientation angles in the solder joints was much more complicated. As Pb was contained in the solder joints and the stress was concentrated on the corner of the mixed solder joints, concaves and cracks were formed. When the adjacent recrystallized subgrains were separated, and the process of the continuous recrystallization was limited.
Maintaining Low Voiding Solder Die Attach for Power Die While Minimizing Die Tilt

Energy Technology Data Exchange (ETDEWEB)

Hamm, Randy; Peterson, Kenneth A.

2015-10-01

This paper addresses work to minimize voiding and die tilt in solder attachment of a large power die, measuring 9.0 mm X 6.5 mm X 0.1 mm (0.354” x 0.256” x 0.004”), to a heat spreader. As demands for larger high power die continue, minimizing voiding and die tilt is of interest for improved die functionality, yield, manufacturability, and reliability. High-power die generate considerable heat, which is important to dissipate effectively through control of voiding under high thermal load areas of the die while maintaining a consistent bondline (minimizing die tilt). Voiding was measured using acoustic imaging and die tilt was measured using two different optical measurement systems. 80Au-20Sn solder reflow was achieved using a batch vacuum solder system with optimized fixturing. Minimizing die tilt proved to be the more difficult of the two product requirements to meet. Process development variables included tooling, weight and solder preform thickness.
Improvement of the auto wire feeder machine in a de-soldering process

Directory of Open Access Journals (Sweden)

Niramon Nonkhukhetkhong

2016-10-01

Full Text Available This paper presents the methodology of the de-soldering process for rework of disk drive Head Stack Assembly (HSA units. The auto wire feeder is a machine that generates Tin (Sn on the product. This machine was determined to be one of the major sources of excess Sn on the HSA. The defect rate due to excess Sn is more than 30%, which leads to increased processing time and cost to perform additional cleaning steps. From process analysis, the major causes of excess Sn are as follows: 1 The machine cannot cut the wire all the way into the flux core area; 2 The sizes and types of soldering irons are not appropriate for the unit parts; and, 3 There are variations introduced into the de-soldering process by the workforce. This paper proposes a methodology to address all three of these causes. First, the auto wire feeder machine in the de-solder process will be adjusted in order to cut wires into flux core. Second, the types of equipment and material used in de-soldering will be optimized. Finally, a new standard method for operators, which can be controlled more easily, will be developed in order to reduce defects due to workforce related variation. After these process controls and machine adjustments were implemented, the overall Sn related problems were significantly improved. Sn contamination was reduced by 41% and cycle time was reduced by an average of 15 seconds.
The Effect of Gap Angle on Tensile Strength of Preceramic Base Metal Solder Joints.

Science.gov (United States)

Fattahi, Farnaz; Hashemi Ardakani, Zahra; Hashemi Ardakani, Maryam

2015-12-01

Soldering is a process commonly used in fabricating dental prosthesis. Since most soldered prosthesis fail at the solder joints; the joint strength is of utmost importance. The purpose of this study was to evaluate the effect of gap angle on the tensile strength of base metal solder joints. A total number of 40 Ni-Cr samples were fabricated according to ADA/ISO 9693 specifications for tensile test. Samples were cut at the midpoint of the bar, and were placed at the considered angles by employing an explicitly designed device. They were divided into 4 groups regarding the gap angle; Group C (control group) with parallel gap on steady distance of 0.2mm, Group 1: 10°, Group 2: 20°, and Group3: 30° gap angles. When soldered, the specimens were all tested for tensile strength using a universal testing machine at a cross-head speed of 0.5 mm/min with a preload of 10N. Kruskal-Wallis H test was used to compare tensile strength among the groups (ptensile strength values obtained from the study groups were respectively 307.84, 391.50, 365.18, and 368.86 MPa. The tensile strength was not statistically different among the four groups in general (p≤ 0.490). Making the gap angular at the solder joints and the subsequent unsteady increase of the gap distance would not change the tensile strength of the joint.
Fluxless flip-chip bonding using a lead-free solder bumping technique

Science.gov (United States)

Hansen, K.; Kousar, S.; Pitzl, D.; Arab, S.

2017-09-01

With the LHC exceeding the nominal instantaneous luminosity, the current barrel pixel detector (BPIX) of the CMS experiment at CERN will reach its performance limits and undergo significant radiation damage. In order to improve detector performance in high luminosity conditions, the entire BPIX is replaced with an upgraded version containing an additional detection layer. Half of the modules comprising this additional layer are produced at DESY using fluxless and lead-free bumping and bonding techniques. Sequential solder-jetting technique is utilized to wet 40-μm SAC305 solder spheres on the silicon-sensor pads with electroless Ni, Pd and immersion Au (ENEPIG) under-bump metallization (UBM). The bumped sensors are flip-chip assembled with readout chips (ROCs) and then reflowed using a flux-less bonding facility. The challenges for jetting low solder volume have been analyzed and will be presented in this paper. An average speed of 3.4 balls per second is obtained to jet about 67 thousand solder balls on a single chip. On average, 7 modules have been produced per week. The bump-bond quality is evaluated in terms of electrical and mechanical properties. The peak-bump resistance is about 17.5 mΩ. The cross-section study revealed different types of intermetallic compounds (IMC) as a result of interfacial reactions between UBM and solder material. The effect of crystalline phases on the mechanical properties of the joint is discussed. The mean shear strength per bump after the final module reflow is about 16 cN. The results and sources of yield loss of module production are reported. The achieved yield is 95%.
Nanoscale Soldering of Positioned Carbon Nanotubes using Highly Conductive Electron Beam Induced Gold Deposition

DEFF Research Database (Denmark)

Madsen, Dorte Nørgaard; Mølhave, Kristian; Mateiu, Ramona Valentina

2003-01-01

We have developed an in-situ method for controlled positioning of carbon nanotubes followed by highly conductive contacting of the nanotubes, using electron beam assisted deposition of gold. The positioning and soldering process takes place inside an Environmental Scanning Electron Microscope (E...... in a carbon matrix. Nanoscale soldering of multi-walled carbon nanotubes (MWNT) onto microelectrodes was achieved by deposition of a conducting gold line across a contact point between nanotube and electrode. The solderings were found to be mechanically stronger than the carbon nanotubes. We have positioned...... MWNTs to bridge the gap between two electrodes, and formed soldering bonds between the tube and each of the electrodes. All nanotube bridges showed ohmic resistances in the range 10-30 kΩ. We observed no increase in resistance after exposing the MWNT bridge to air for days....
The formation mechanism for printed silver-contacts for silicon solar cells.

Science.gov (United States)

Fields, Jeremy D; Ahmad, Md Imteyaz; Pool, Vanessa L; Yu, Jiafan; Van Campen, Douglas G; Parilla, Philip A; Toney, Michael F; van Hest, Maikel F A M

2016-04-01

Screen-printing provides an economically attractive means for making Ag electrical contacts to Si solar cells, but the use of Ag substantiates a significant manufacturing cost, and the glass frit used in the paste to enable contact formation contains Pb. To achieve optimal electrical performance and to develop pastes with alternative, abundant and non-toxic materials, a better understanding the contact formation process during firing is required. Here, we use in situ X-ray diffraction during firing to reveal the reaction sequence. The findings suggest that between 500 and 650 °C PbO in the frit etches the SiNx antireflective-coating on the solar cell, exposing the Si surface. Then, above 650 °C, Ag(+) dissolves into the molten glass frit - key for enabling deposition of metallic Ag on the emitter surface and precipitation of Ag nanocrystals within the glass. Ultimately, this work clarifies contact formation mechanisms and suggests approaches for development of inexpensive, nontoxic solar cell contacting pastes.

In-situ study of electromigration-induced grain rotation in Pb-free solder joint by synchrotron microdiffraction

Energy Technology Data Exchange (ETDEWEB)

Chen, Kai; Tamura, Nobumichi; Tu, King-Ning

2008-10-31

The rotation of Sn grains in Pb-free flip chip solder joints hasn't been reported in literature so far although it has been observed in Sn strips. In this letter, we report the detailed study of the grain orientation evolution induced by electromigration by synchrotron based white beam X-ray microdiffraction. It is found that the grains in solder joint rotate more slowly than in Sn strip even under higher current density. On the other hand, based on our estimation, the reorientation of the grains in solder joints also results in the reduction of electric resistivity, similar to the case of Sn strip. We will also discuss the reason why the electric resistance decreases much more in strips than in the Sn-based solders, and the different driving force for the grain growth in solder joint and in thin film interconnect lines.
Research on Defects Inspection of Solder Balls Based on Eddy Current Pulsed Thermography

Directory of Open Access Journals (Sweden)

Xiuyun Zhou

2015-10-01

Full Text Available In order to solve tiny defect detection for solder balls in high-density flip-chip, this paper proposed feasibility study on the effect of detectability as well as classification based on eddy current pulsed thermography (ECPT. Specifically, numerical analysis of 3D finite element inductive heat model is generated to investigate disturbance on the temperature field for different kind of defects such as cracks, voids, etc. The temperature variation between defective and non-defective solder balls is monitored for defects identification and classification. Finally, experimental study is carried on the diameter 1mm tiny solder balls by using ECPT and verify the efficacy of the technique.
Eddy current quality control of soldered current-carrying busbar splices of superconducting magnets

CERN Document Server

Kogan, L; Savary, F; Principe, R; Datskov, V; Rozenfel'd, E; Khudjakov, B

2015-01-01

The eddy current technique associated with a U-shaped transducer is studied for the quality control of soldered joints between superconducting busbars ('splices'). Two other quality control techniques, based on X-rays and direct measurement of the electrical resistance, are also studied for comparison. A comparative analysis of the advantages and disadvantages of these three methods in relation to the quality control of soldered superconducting busbar cables enclosed in copper shells is used for benchmarking. The results of inspections with the U-shaped eddy current transducer carried out on several sample joints presenting different types of soldering defects show the potential of this type of nondestructive (ND) quality control technique.
Reliability of Pb free solder alloys. Physical and mechanical properties; Pb free handa no shinraisei. Butsuri kikaiteki shinraisei

Energy Technology Data Exchange (ETDEWEB)

Sanji, M; Yoshino, M; Ishikawa, J; Takenaka, O [Denso Corp., Aichi (Japan)

1997-10-01

Properties of 19 different Pb free solders have been evaluated in comparison with Sn-37Pb eutectic solder. Pb free solders without Bi were on the same level as Sn-37Pb in tensile strength and elongation, and those with Bi had higher strength and lower elongation than Sn-37Pb. As the Bi content increased, strength was higher, and elongation was lower. In torsion fatigue tests, fatigue life of Pb free solders without Bi was longer than Sn-37Pb. The relationships of Coffin-Manson rule and Basquin rule with fatigue life was applicable to Pb free solder. Fatigue life of those is inferred from their tensile strength. 7 refs., 13 figs., 1 tab.
Laser tissue welding mediated with a protein solder

Science.gov (United States)

Small, Ward, IV; Heredia, Nicholas J.; Celliers, Peter M.; Da Silva, Luiz B.; Eder, David C.; Glinsky, Michael E.; London, Richard A.; Maitland, Duncan J.; Matthews, Dennis L.; Soltz, Barbara A.

1996-05-01

A study of laser tissue welding mediated with an indocyanine green dye-enhanced protein solder was performed. Freshly obtained sections of porcine artery were used for the experiments. Sample arterial wall thickness ranged from two to three millimeters. Incisions approximately four millimeters in length were treated using an 805 nanometer continuous- wave diode laser coupled to a one millimeter diameter fiber. Controlled parameters included the power delivered by the laser, the duration of the welding process, and the concentration of dye in the solder. A two-color infrared detection system was constructed to monitor the surface temperatures achieved at the weld site. Burst pressure measurements were made to quantify the strengths of the welds immediately following completion of the welding procedure.
TECHNOLOGY DEMONSTRATION OF SLUDGE MASS REDUCTION VIA ALUMINUM DISSOLUTION: GLASS FORMULATION PROCESSING WINDOW PREDICTIONS FOR SB5

International Nuclear Information System (INIS)

Fox, K.; Tommy Edwards, T.; David Peeler, D.

2007-01-01

Composition projections for Sludge Batch 5 (SB5) were developed, based on a modeling approach at the Savannah River National Laboratory (SRNL), to evaluate possible impacts of the Al-dissolution process on the availability of viable frit compositions for vitrification at the Defense Waste Processing Facility (DWPF). The study included two projected SB5 compositions that bound potential outcomes (or degrees of effectiveness) of the Al-dissolution process, as well as a nominal SB5 composition projection based on the results of the recent Al-dissolution demonstration at SRNL. The three SB5 projections were the focus of a two-stage paper study assessment. A Nominal Stage assessment combined each of the SB5 composition projections with an array of 19,305 frit compositions over a wide range of waste loading (WL) values and evaluated them against the DWPF process control models. The Nominal Stage results allowed for the down-selection of a small number of frits that provided reasonable projected operating windows (typically 27 to 42 wt% WL). The frit/sludge systems were mostly limited by process related constraints, with only one system being limited by predictions of nepheline crystallization, a waste form affecting constraint. The criteria applied in selecting the frit compositions somewhat restricted the compositional flexibility of the candidate frits for each individual SB5 composition projection, which may limit the ability to further tailor the frit for improved melt rate. Variation Stage assessments were then performed using the down-selected frits and the three SB5 composition projections with variation applied to each sludge component. The Variation Stage results showed that the operating windows were reduced in width, as expected when variation in the sludge composition is applied. However, several of the down-selected frits exhibited a relatively high degree of robustness to the applied sludge variation, providing WL windows of approximately 30 to 39 wt%. The
Electrical Resistance of Nb$_{3}$Sn/Cu Splices Produced by Electromagnetic Pulse Technology and Soft Soldering

CERN Document Server

Schoerling, D; Scheuerlein, C; Atieh, S; Schaefer, R

2011-01-01

The electrical interconnection of Nb$_{3}$Sn/Cu strands is a key issue for the construction of Nb$_{3}$Sn based damping ring wigglers and insertion devices for third generation light sources. We compare the electrical resistance of Nb$_{3}$Sn/Cu splices manufactured by solid state welding using Electromagnetic Pulse Technology (EMPT) with that of splices produced by soft soldering with two different solders. The resistance of splices produced by soft soldering depends strongly on the resistivity of the solder alloy at the operating temperature. By solid state welding splice resistances below 10 nOhm can be achieved with 1 cm strand overlap length only, which is about 4 times lower than the resistance of Sn96Ag4 soldered splices with the same overlap length. The comparison of experimental results with Finite Element simulations shows that the electrical resistance of EMPT welded splices is determined by the resistance of the stabilizing copper between the superconducting filaments and confirms that welding of ...
Microstructural Evolution and Mechanical Behavior of High Temperature Solders: Effects of High Temperature Aging

Science.gov (United States)

Hasnine, M.; Tolla, B.; Vahora, N.

2018-04-01

This paper explores the effects of aging on the mechanical behavior, microstructure evolution and IMC formation on different surface finishes of two high temperature solders, Sn-5 wt.% Ag and Sn-5 wt.% Sb. High temperature aging showed significant degradation of Sn-5 wt.% Ag solder hardness (34%) while aging has little effect on Sn-5 wt.% Sb solder. Sn-5 wt.% Ag experienced rapid grain growth as well as the coarsening of particles during aging. Sn-5 wt.% Sb showed a stable microstructure due to solid solution strengthening and the stable nature of SnSb precipitates. The increase of intermetallic compound (IMC) thickness during aging follows a parabolic relationship with time. Regression analysis (time exponent, n) indicated that IMC growth kinetics is controlled by a diffusion mechanism. The results have important implications in the selection of high temperature solders used in high temperature applications.
IFSA: a microfluidic chip-platform for frit-based immunoassay protocols

Science.gov (United States)

Hlawatsch, Nadine; Bangert, Michael; Miethe, Peter; Becker, Holger; Gärtner, Claudia

2013-03-01

Point-of-care diagnostics (POC) is one of the key application fields for lab-on-a-chip devices. While in recent years much of the work has concentrated on integrating complex molecular diagnostic assays onto a microfluidic device, there is a need to also put comparatively simple immunoassay-type protocols on a microfluidic platform. In this paper, we present the development of a microfluidic cartridge using an immunofiltration approach. In this method, the sandwich immunoassay takes place in a porous frit on which the antibodies have immobilized. The device is designed to be able to handle three samples in parallel and up to four analytical targets per sample. In order to meet the critical cost targets for the diagnostic market, the microfluidic chip has been designed and manufactured using high-volume manufacturing technologies in mind. Validation experiments show comparable sensitivities in comparison with conventional immunofiltration kits.
Laser solder welding of articular cartilage: tensile strength and chondrocyte viability.

Science.gov (United States)

Züger, B J; Ott, B; Mainil-Varlet, P; Schaffner, T; Clémence, J F; Weber, H P; Frenz, M

2001-01-01

The surgical treatment of full-thickness cartilage defects in the knee joint remains a therapeutic challenge. Recently, new techniques for articular cartilage transplantation, such as mosaicplasty, have become available for cartilage repair. The long-term success of these techniques, however, depends not only on the chondrocyte viability but also on a lateral integration of the implant. The goal of this study was to evaluate the feasibility of cartilage welding by using albumin solder that was dye-enhanced to allow coagulation with 808-nm laser diode irradiation. Conventional histology of light microscopy was compared with a viability staining to precisely determine the extent of thermal damage after laser welding. Indocyanine green (ICG) enhanced albumin solder (25% albumin, 0.5% HA, 0.1% ICG) was used for articular cartilage welding. For coagulation, the solder was irradiated through the cartilage implant by 808-nm laser light and the tensile strength of the weld was measured. Viability staining revealed a thermal damage of typically 500 m in depth at an irradiance of approximately 10 W/cm(2) for 8 seconds, whereas conventional histologies showed only half of the extent found by the viability test. Heat-bath investigations revealed a threshold temperature of minimum 54 degrees C for thermal damage of chondrocytes. Efficient cartilage bonding was obtained by using bovine albumin solder as adhesive. Maximum tensile strength of more than 10 N/cm(2) was achieved. Viability tests revealed that the thermal damage is much greater (up to twice) than expected after light microscopic characterization. This study shows the feasibility to strongly laser weld cartilage on cartilage by use of a dye-enhanced albumin solder. Possibilities to reduce the range of damage are suggested. Copyright 2001 Wiley-Liss, Inc.
Fabrication and characterization of MCC approved testing material: ATM-11 glass

International Nuclear Information System (INIS)

Wald, J.W.; Daniel, J.L.

1986-08-01

ATM-11 glass is designed to be representative of defense high-level waste glasses that will be produced by the Defense Waste Processing Facility at the Savannah River Plant in Aiken, South Carolina. It is representative of a 300-year-old nuclear waste glass and was intended as a conservative compromise between 10-year-old waste and 1000-year-old waste. The feedstock material for this glass was supplied by Savannah River Laboratory, Aiken, SC, as SRL-165 black frit to which was added Ba, Cs, Mo, Nd, Ni, Pd, Rb, Ru, Sr, Te, Y, and Zr, as well as 241 Am, 237 Np, /sup 239+240/Pu, 151 Sm, 99 Tc, and depleted U. The glass was melted under the reducing conditions that resulted from the addition of 0.7 wt% graphite during the final melting process. Nearly 3 kg of ATM-11 glass were produced from a feedstock melted in a nitrogen-atmosphere glove box at 1250 0 C in Denver Fire Clay crucibles. After final melting, the glass was formed into stress-annealed rectangular bars 1.9 x 1.9 x 10 cm nominal size. Twenty-six bars were cast with a nominal weight of about 100 g each. The analyzed composition of ATM-11 glass is tabulated. Examination of a single transverse section from one bar by reflected light microscopy showed random porosity estimated at 0.4 vol% with nominal pore diameters ranging from ∼5 μm to 175 μm. A distinct randomly distributed second phase was observed at a very low concentration in the glass matrix as agglomerated, metallic-like clusters. One form of the aggregates contained mainly a high concentration of iron, while a second form had regions of high nickel concentration, and of high palladium concentration. All aggregates also contained a low concentration of technetium and/or ruthenium. An autoradiograph of the sample provided an indication of the total radionuclide ditribution. X-ray diffraction analysis of this same sample indicates that the glass probably contained 5 wt% crystalline material
Contamination profile of Printed Circuit Board Assemblies in relation to soldering types and conformal coating

DEFF Research Database (Denmark)

Conseil, Helene; Jellesen, Morten Stendahl; Ambat, Rajan

2014-01-01

Typical printed circuit board assemblies (PCBAs) processed by reflow, wave, or selective wave soldering were analysed for typical levels of process related residues, resulting from a specific or combination of soldering process. Typical solder flux residue distribution pattern, composition......, and concentration are profiled and reported. Presence of localized flux residues were visualized using a commercial Residue RAT gel test and chemical structure was identified by FT-IR, while the concentration was measured using ion chromatography, and the electrical properties of the extracts were determined...
Vitrification of copper flotation waste

Energy Technology Data Exchange (ETDEWEB)

Karamanov, Alexander [Institute of Physical Chemistry, Bulgarian Academy of Science, G. Bonchev Str. Block 11, 1113 Sofia (Bulgaria)]. E-mail: karama@ing.univaq.it; Aloisi, Mirko [Department of Chemistry, Chemical Engineering and Materials, University of L' Aquila, 67040 Monteluco di Roio, L' Aquila (Italy); Pelino, Mario [Department of Chemistry, Chemical Engineering and Materials, University of L' Aquila, 67040 Monteluco di Roio, L' Aquila (Italy)

2007-02-09

The vitrification of an hazardous iron-rich waste (W), arising from slag flotation of copper production, was studied. Two glasses, containing 30 wt% W were melted for 30 min at 1400 deg. C. The first batch, labeled WSZ, was obtained by mixing W, blast furnace slag (S) and zeolite tuff (Z), whereas the second, labeled WG, was prepared by mixing W, glass cullet (G), sand and limestone. The glass frits showed high chemical durability, measured by the TCLP test. The crystallization of the glasses was evaluated by DTA. The crystal phases formed were identified by XRD resulting to be pyroxene and wollastonite solid solutions, magnetite and hematite. The morphology of the glass-ceramics was observed by optical and scanning electron microscopy. WSZ composition showed a high rate of bulk crystallization and resulted to be suitable for producing glass-ceramics by a short crystallization heat-treatment. WG composition showed a low crystallization rate and good sinterability; glass-ceramics were obtained by sinter-crystallization of the glass frit.
Vitrification of copper flotation waste.

Science.gov (United States)

Karamanov, Alexander; Aloisi, Mirko; Pelino, Mario

2007-02-09

The vitrification of an hazardous iron-rich waste (W), arising from slag flotation of copper production, was studied. Two glasses, containing 30wt% W were melted for 30min at 1400 degrees C. The first batch, labeled WSZ, was obtained by mixing W, blast furnace slag (S) and zeolite tuff (Z), whereas the second, labeled WG, was prepared by mixing W, glass cullet (G), sand and limestone. The glass frits showed high chemical durability, measured by the TCLP test. The crystallization of the glasses was evaluated by DTA. The crystal phases formed were identified by XRD resulting to be pyroxene and wollastonite solid solutions, magnetite and hematite. The morphology of the glass-ceramics was observed by optical and scanning electron microscopy. WSZ composition showed a high rate of bulk crystallization and resulted to be suitable for producing glass-ceramics by a short crystallization heat-treatment. WG composition showed a low crystallization rate and good sinterability; glass-ceramics were obtained by sinter-crystallization of the glass frit.
Vitrification of copper flotation waste

International Nuclear Information System (INIS)

Karamanov, Alexander; Aloisi, Mirko; Pelino, Mario

2007-01-01

The vitrification of an hazardous iron-rich waste (W), arising from slag flotation of copper production, was studied. Two glasses, containing 30 wt% W were melted for 30 min at 1400 deg. C. The first batch, labeled WSZ, was obtained by mixing W, blast furnace slag (S) and zeolite tuff (Z), whereas the second, labeled WG, was prepared by mixing W, glass cullet (G), sand and limestone. The glass frits showed high chemical durability, measured by the TCLP test. The crystallization of the glasses was evaluated by DTA. The crystal phases formed were identified by XRD resulting to be pyroxene and wollastonite solid solutions, magnetite and hematite. The morphology of the glass-ceramics was observed by optical and scanning electron microscopy. WSZ composition showed a high rate of bulk crystallization and resulted to be suitable for producing glass-ceramics by a short crystallization heat-treatment. WG composition showed a low crystallization rate and good sinterability; glass-ceramics were obtained by sinter-crystallization of the glass frit
Effects of voids on thermal-mechanical reliability of lead-free solder joints

Directory of Open Access Journals (Sweden)

Benabou Lahouari

2014-06-01

Full Text Available Reliability of electronic packages has become a major issue, particularly in systems used in electrical or hybrid cars where severe operating conditions must be met. Many studies have shown that solder interconnects are critical elements since many failure mechanisms originate from their typical response under thermal cycles. In this study, effects of voids in solder interconnects on the electronic assembly lifetime are estimated based on finite element simulations.
Technical Report on the Impact of MgO on Defense Waste Processing Facility

International Nuclear Information System (INIS)

Schultz, R.L.

2000-01-01

The purpose of this study was to determine the effect(s) of removing MgO from DWPF frits to assess the impact on liquidus temperature and the durability of the glass product. Removal of MgO from the frit was hypothesized to lead to a decrease in liquidus temperature and thereby allow increased waste loading
Modeling of high temperature- and diffusion-controlled die soldering in aluminum high pressure die casting

DEFF Research Database (Denmark)

Domkin, Konstantin; Hattel, Jesper Henri; Thorborg, Jesper

2009-01-01

of the die lifetime based on a quantitative analysis of die soldering in the framework of the numerical simulations of the die-casting process. Full 3D simulations of the process, including the filling. solidification, and the die cooling, are carried out using the casting simulation software MAGMAsoft....... The resulting transient temperature fields on the die surface and in the casting are then post-processed to estimate the die soldering. The present work deals only with the metallurgical/chemical kind of soldering which occurs at high temperatures and involves formation and growth of intermetallic layers...
Effect of rare earth Ce on the fatigue life of SnAgCu solder joints in WLCSP device using FEM and experiments

International Nuclear Information System (INIS)

Zhang, Liang; Han, Ji-guang; Guo, Yong-huan; He, Cheng-wen

2014-01-01

With the addition of 0.03 wt% rare earth Ce, in our previous works, the properties of SnAgCu solder were enhanced obviously. Based on the Garofalo–Arrhenius creep constitutive model, finite element method was used to simulate the stress–strain response during thermal cycle loading, and combined with the fatigue life prediction models, the fatigue life of SnAgCu/SnAgCuCe solder joints was calculated respectively, which can demonstrate the effect of the rare earth Ce on the fatigue life of SnAgCu solder joints. The results indicated that the maximum stress–strain can be found on the top surface of the corner solder joint, and the warpage of the PCB substrate occurred during thermal cycle loading. The trends obtained from modeling results have a good agreement with the experimental data reported in the literature for WLCSP devices. In addition, the stress–strain of SnAgCuCe solder joints is lower than that of SnAgCu solder joints. The thermal fatigue lives of solder joints calculated based on the creep model and creep strain energy density model show that the fatigue life of SnAgCuCe solder joints is higher than the SnAgCu solder joints. The fatigue life of SnAgCuCe solder joints can be enhanced significantly with the addition of Ce, is 30.2% higher than that of SnAgCu solder joints, which can be attributed to the CeSn 3 particles formed resisting the motion of dislocation; moreover, the refinement of microstructure and the IMC sizes also contribute to the enhancement of fatigue life, which elucidates that SnAgCuCe solder can be utilized in electronic industry with high reliability replacing the SnAgCu solder
Dissolution ad uptake of cadmium from dental gold solder alloy implants

International Nuclear Information System (INIS)

Bergman, B.; Bergman, M.; Soeremark, R.

1977-01-01

Pure metallic cadmium was irradiated by means of thermal neutrons. The irradiated cadmium ( 115 Cd) was placed in bags of gold foil and the bags were implanted subcutaneously in the neck region of mice. Two and 3 d respectively after implantation the mice were killed, the bags removed and the animals subjected to whole-body autoradiography. The autoradiograms revealed an uptake of 115 Cd in liver and kidney. In another experiment specimens of a cadmium-containing dental gold solder alloy, a cadmium-free dental casting gold alloy and soldered assemblies made of these two alloys were implanted subcutaneously in the neck region of mice. The animals were killed after 6 months; cadmium analysis showed significant increases in the cadmium concentration in liver and kidney of those mice which had been given implants of gold solder alloy. The study clearly shows that due to electrochemical corrosion cadmium can be released from implants and accumulated in the kidneys and the liver. (author)

Dissolution and uptake of cadmium from dental gold solder alloy implants

Energy Technology Data Exchange (ETDEWEB)

Bergman, B; Bergman, M; Soeremark, R [Umeaa Univ. (Sweden); Karolinska Institutet, Stockholm (Sweden))

1977-01-01

Pure metallic cadmium was irradiated by means of thermal neutrons. The irradiated cadmium (/sup 115/Cd) was placed in bags of gold foil and the bags were implanted subcutaneously in the neck region of mice. Two and 3 d respectively after implantation the mice were killed, the bags removed and the animals subjected to whole-body autoradiography. The autoradiograms revealed an uptake of /sup 115/Cd in liver and kidney. In another experiment specimens of a cadmium-containing dental gold solder alloy, a cadmium-free dental casting gold alloy and soldered assemblies made of these two alloys were implanted subcutaneously in the neck region of mice. The animals were killed after 6 months; cadmium analysis showed significant increases in the cadmium concentration in liver and kidney of those mice which had been given implants of gold solder alloy. The study clearly shows that due to electrochemical corrosion cadmium can be released from implants and accumulated in the kidneys and the liver.
The Shear Strength and Fracture Behavior of Sn-Ag- xSb Solder Joints with Au/Ni-P/Cu UBM

Science.gov (United States)

Lee, Hwa-Teng; Hu, Shuen-Yuan; Hong, Ting-Fu; Chen, Yin-Fa

2008-06-01

This study investigates the effects of Sb addition on the shear strength and fracture behavior of Sn-Ag-based solders with Au/Ni-P/Cu underbump metallization (UBM) substrates. Sn-3Ag- xSb ternary alloy solder joints were prepared by adding 0 wt.% to 10 wt.% Sb to a Sn-3.5Ag alloy and joining them with Au/Ni-P/Cu UBM substrates. The solder joints were isothermally stored at 150°C for up to 625 h to study their microstructure and interfacial reaction with the UBM. Single-lap shear tests were conducted to evaluate the mechanical properties, thermal resistance, and failure behavior. The results show that UBM effectively suppressed intermetallic compound (IMC) formation and growth during isothermal storage. The Sb addition helped to refine the Ag3Sn compounds, further improving the shear strength and thermal resistance of the solders. The fracture behavior evolved from solder mode toward the mixed mode and finally to the IMC mode with increasing added Sb and isothermal storage time. However, SnSb compounds were found in the solder with 10 wt.% Sb; they may cause mechanical degradation of the solder after long-term isothermal storage.
CO2 temperature-controlled laser soldering of pig trachea incisions in vitro using flexible albumin bands

Science.gov (United States)

Sharvit, Dan; Vasilyev, Tamar; Vasserman, Irena; Simhon, David; Kariv, Naam; DeRowe, Ari; Katzir, Abraham

2005-04-01

Resection of a segment of the trachea is a procedure applied for the removal of cervical tumors invading the trachea, or for the treatment of severe tracheal stenosis. The current method of anastomosis is based on multiple sutures. The main drawbacks of this method are: 1) A long procedure time, 2) An air leakage, and 3) An inflammatory response to the sutures. In this study we evaluated the feasibility and effectiveness of the use of temperature controlled CO2 laser soldering of incisions in pig tracheas in vitro. A transverse incision was made in a separated pig trachea. A flexible albumin band was prepared and was laser soldered with albumin solder to the outer surface of the trachea, covering the incision. The soldered trachea ends were sealed and the burst pressure was measured. In a series of in vitro experiments, the mean burst pressure was found to be 230 mm Hg. These preliminary results demonstrated that laser soldering using a flexible albumin band may be a useful method for sealing an incision in the trachea.
Instantaneous fluxless bonding of Au with Pb-Sn solder in ambient atmosphere

International Nuclear Information System (INIS)

Lee, T.K.; Zhang, Sam; Wong, C.C.; Tan, A.C.

2005-01-01

A fluxless bonding technique has been developed as a method of flip-chip bonding for microelectronic packaging. The fluxless bonding technique can be achieved instantaneously in an ambient environment between metallic stud bumps and predefined molten solder. This paper describes the mechanics of the bonding action and verifies the effectiveness of this bonding method through wetting balance tests and scanning electron microscope and energy dispersive x-ray analysis. This technique has been demonstrated by using a gold stud bump to break the tin oxide layer over molten solder. This allows for a fast, solid liquid interdiffusion between gold (Au) and the fresh molten eutectic lead-tin (Pb-Sn) solder for joint formation during solidification. This bonding method has been successfully tested with 130-μm-pitch flip-chip bond pads on a joint-in-via flex substrate architecture
SINGLE IMAGE CAMERA CALIBRATION IN CLOSE RANGE PHOTOGRAMMETRY FOR SOLDER JOINT ANALYSIS

Directory of Open Access Journals (Sweden)

D. Heinemann

2016-06-01

Full Text Available Printed Circuit Boards (PCB play an important role in the manufacturing of electronic devices. To ensure a correct function of the PCBs a certain amount of solder paste is needed during the placement of components. The aim of the current research is to develop an real-time, closed-loop solution for the analysis of the printing process where solder is printed onto PCBs. Close range photogrammetry allows for determination of the solder volume and a subsequent correction if necessary. Photogrammetry is an image based method for three dimensional reconstruction from two dimensional image data of an object. A precise camera calibration is indispensable for an accurate reconstruction. In our certain application it is not possible to use calibration methods with two dimensional calibration targets. Therefore a special calibration target was developed and manufactured, which allows for single image camera calibration.
The Effect of Reflow on Wettability of Sn 96.5 Ag 3 Cu 0.5 Solder

Directory of Open Access Journals (Sweden)

Zoltán Weltsch

2012-11-01

Full Text Available Surface conditions on Printed Circuit Board (PCB final finishes have an important impact on the wetting behaviour with lead-free solder. The improvement of wettability in liquid Sn 96.5 Ag 3 Cu 0.5 Solder alloy on PCB substrate was measured with a sessile drop method at 523 K temperature. Wetting properties was determined in normal atmospheric air and inert atmosphere. The wetting angles increasing with the number of reflows both atmosphere. The effect of the atmosphere has a huge importance of the oxidation which manifests itself of the measured wetting angles. One of the most important factors to the wetting properties is the amount of oxygen in the soldering atmosphere. Using the inert atmosphere is crucial to Pb-free solders, particularly after reflows.
Reliability and microstructure of lead-free solder joints in industrial electronics after accelerated thermal aging

NARCIS (Netherlands)

Scaltro, F.; Biglari, M.H.; Kodentsov, A.; Yakovleva, O.; Brom, E.

2009-01-01

The reliability of lead-free (LF) solder joints in surface-mounted device components (SMD) has been investigated after thermo-cycle testing. Kirkendall voids have been observed at the interface component/solder together with the formation of fractures. The evolution, the morphology and the elemental
Development of Sn-Ag-Cu-X Solders for Electronic Assembly by Micro-Alloying with Al

Science.gov (United States)

Boesenberg, Adam J.; Anderson, Iver E.; Harringa, Joel L.

2012-07-01

Of Pb-free solder choices, an array of solder alloys based on the Sn-Ag-Cu (SAC) ternary eutectic ( T eut = 217°C) composition have emerged with potential for broad use, including ball grid array (BGA) joints that cool slowly. This work investigated minor substitutional additions of Al (0.05Al), but the suppression effect faded for >0.20Al. Undercooling suppression did not correlate specifically with blade suppression since it became significant at 0.10Al and increased continuously with greater Al to 0.25Al. Surprisingly, an intermediate range of Al content (0.10 wt.% to 0.20 wt.% Al) promoted formation of significant populations of 2- μm to 5- μm faceted Cu-Al particles, identified as Cu33Al17, that clustered at the top of the solder joint matrix and exhibited extraordinary hardness. Clustering of Cu33Al17 was attributed to its buoyancy, from a lower density than Sn liquid, and its early position in the nucleation sequence within the solder matrix, permitting unrestricted migration to the top interface. Joint microstructures and implications for the full nucleation sequence for these SAC + Al solder joints are discussed, along with possible benefits from the clustered particles for improved thermal cycling resistance.
Au-Ge based Candidate Alloys for High-Temperature Lead-Free Solder Alternatives

DEFF Research Database (Denmark)

Chidambaram, Vivek; Hald, John; Hattel, Jesper Henri

2009-01-01

Au-Ge based candidate alloys have been proposed as an alternative to high-lead content solders that are currently being used for high-temperature applications. The influence of the low melting point metals namely In, Sb and Sn to the Au-Ge eutectic with respect to the microstructure and microhard......Au-Ge based candidate alloys have been proposed as an alternative to high-lead content solders that are currently being used for high-temperature applications. The influence of the low melting point metals namely In, Sb and Sn to the Au-Ge eutectic with respect to the microstructure...... was primarily strengthened by the refined (Ge) dispersed phase. The distribution of phases played a relatively more crucial role in determining the ductility of the bulk solder alloy. In the present work it was found that among the low melting point metals, the addition of Sb to the Au-Ge eutectic would...
The effect of micro alloying on the microstructure evolution of Sn-Ag-Cu lead-free solder

Science.gov (United States)

Werden, Jesse

The microelectronics industry is required to obtain alternative Pb-free soldering materials due to legal, environmental, and technological factors. As a joining material, solder provides an electrical and mechanical support in electronic assemblies and therefore, the properties of the solder are crucial to the durability and reliability of the solder joint and the function of the electronic device. One major concern with new Pb-free alternatives is that the microstructure is prone to microstructural coarsening over time which leads to inconsistent properties over the device's lifetime. Power aging the solder is a common method of stabilizing the microstructure for Pb-based alloys, however, it is unclear if this will be an appropriate solution to the microstructural coarsening of Pb-free solders. The goal of this work is to develop a better understanding of the coarsening process in new solder alloys and to suggest methods of stabilizing the solder microstructure. Microalloying is one potential solution to the microstructural coarsening problem. This experiment consists of a microstructural coarsening study of SAC305 in which each sample has been alloyed with one of three different solutes, directionally solidified at 100microm/s, and then aged at three different temperatures over a total period of 20 days. There are several important conclusions from this experiment. First, the coarsening kinetics of the intermetallics in the ternary eutectic follow the Ostwald ripening model where r3 in proprotional to t for each alloying constituent. Second, the activation energy for coarsening was found to be 68.1+/-10.3 kJ/mol for the SAC305 samples, Zn had the most significant increase in the activation energy increasing it to 88.8+/-34.9 kJ/mol for the SAC+Zn samples, Mn also increased the activation energy to 83.2+/-20.8 kJ/mol for the SAC+Mn samples, and Sb decreased the activation energy to 48.0+/-3.59 kJ/mol for the SAC+Sb samples. Finally, it was found that the
Developments of high strength Bi-containing Sn0.7Cu lead-free solder alloys prepared by directional solidification

Energy Technology Data Exchange (ETDEWEB)

Hu, Xiaowu, E-mail: xwhmaterials@aliyun.com [School of Mechanical Electrical Engineering, Nanchang University, Nanchang 330031 (China); Li, Yulong [School of Mechanical Electrical Engineering, Nanchang University, Nanchang 330031 (China); Liu, Yi [School of Materials Science and Engineering, Nanchang University, Nanchang 330031 (China); Min, Zhixian [China Electronics Technology Group Corporation No. 38 Research Institute, Hefei 230088 (China)

2015-03-15

Highlights: • The Sn0.7Cu–xBi solder alloys were directionally solidified. • Both spacing and diameter of fibers decreased with increasing solidification rate. • The UTS and YS first increased with increased solidification rate, then decreased. • The UTS and YS of Sn0.7Cu–xBi first increased with increased Bi content. - Abstract: Bi-containing Sn0.7Cu (SC) eutectic solder alloys were prepared and subjected to directional solidification, through which new types of fiber reinforced eutectic composites were generated. The influences of Bi addition on the microstructures and tensile properties of directionally solidified (DS) Bi-containing eutectic SC lead-free solder alloys have been investigated by using differential scanning calorimetry (DSC), scanning electron microscopy (SEM), energy dispersive spectrometry (EDS) and a tensile testing machine. The experimental results showed that addition of Bi could effectively reduce both the melting temperature and undercooling of SC solder alloy. The microstructures of DS SC–xBi solder alloys were composed of Sn-rich phase (β) and Cu{sub 6}Sn{sub 5} fiber. No other intermetallic compounds (IMCs) with Bi content were observed in the solder matrix for SC solder alloys with various Bi contents. Both fiber spacing and diameter all decreased gradually with increasing growth rate and/or Bi content. Besides, the regularity of Cu{sub 6}Sn{sub 5} fibers alignment also decreased with increasing growth rate, too. The tensile strengths of the SC–xBi eutectic solder alloys varied parabolically with growth rate (R). When R was 60 μm/s, maximum tensile strengths of 43.8, 55.2 and 56.37 MPa were reached for SC, SC0.7Bi and SC1.3Bi solder alloys. A comparison of tensile strength of SC, SC0.7Bi and SC1.3Bi with the same R indicated that the tensile strength increased with increasing Bi content, which was attributed to the presence of Bi and its role in refining microstructure and solid solution strengthening.
Glass composition development for plasma processing of Hanford high sodium content low-level radioactive liquid waste

International Nuclear Information System (INIS)

Marra, J.C.

1995-02-01

To assess the acceptability of prospective compositions, response criteria based on durability, homogeneity, viscosity and volatility were defined. Response variables were weighted: durability 35%, homogeneity 25%, viscosity 25%, volatility 15%. A Plackett-Burman experimental design was used to define the first twelve glass formulations. Glass former additives included Al2O3, B2O3, CaO, Li2O, ZrO2 and SiO2. Lithia was added to facilitate fritting of the additives. The additives were normalized to silica content to ease experimental matrix definition and glass formulation. Preset high and low values of these ratios were determined for the initial twelve melts. Based on rankings of initial compositions, new formulations for testing were developed based on a simplex algorithm. Rating and ranking of subsequent compositions continued until no apparent improvement in glass quality was achieved in newly developed formulations. An optimized composition was determined by averaging the additive component values of the final best performing compositions. The glass former contents to form the optimized glass were: 16.1 wt % Al2O3, 12.3 wt % B2O3, 5.5 wt % CaO, 1.7 wt % Li2O, 3.3 wt % ZrO2, 61.1 wt % SiO2. An optimized composition resulted after only 25 trials despite studying six glass additives. A vitrification campaign was completed using a small-scale Joule heated melter. 80 lbs of glass was produced over 96 hours of continuous operation. Several salt compounds formed and deposited on melter components during the run and likely caused the failure of several pour chamber heaters. In an attempt to minimize sodium volatility, several low or no boron glasses were formulated. One composition containing no boron produced a homogeneous glass worthy of additional testing
Laser Soldering and Thermal Cycling Tests of Monolithic Silicon Pixel Chips

CERN Document Server

Strand, Frode Sneve

2015-01-01

An ALPIDE-1 monolithic silicon pixel sensor prototype has been laser soldered to a flex printed circuit using a novel interconnection technique using lasers. This technique is to be optimised to ensure stable, good quality connections between the sensor chips and the FPCs. To test the long-term stability of the connections, as well as study the effects on hit thresholds and noise in the sensor, it was thermally cycled in a climate chamber 1200 times. The soldered connections showed good qualities like even melting and good adhesion on pad/flex surfaces, and the chip remained in working condition for 1080 cycles. After this, a few connections failed, having cracks in the soldering tin, rendering the chip unusable. Threshold and noise characteristics seemed stable, except for the noise levels of sector 2 in the chip, for 1000 cycles in a temperature interval of "10^{\\circ}" and "50^{\\circ}" C. Still, further testing with wider temperature ranges and more cycles is needed to test the limitations of the chi...
NEPHELINE FORMATION STUDY FOR SLUDGE BATCH 4: PHASE 3 EXPERIMENTAL RESULTS

International Nuclear Information System (INIS)

Fox, K

2006-01-01

This Phase 3 study was undertaken to complement the previous phases of the nepheline formation studies1, 2 by continuing the investigation into the ability of the nepheline discriminator to predict the occurrence of nepheline crystallization in Sludge Batch 4 (SB4) glasses and into the impact of such phases on the durability of the SB4 glasses. The Phase 3 study had two primary objectives. The first was to continue to demonstrate the ability of the discriminator value to adequately predict the nepheline formation potential for specific glass systems of interest. The second was to generate additional data that have a high probability of supporting the SB4 variability study. To support these two objectives, sixteen glasses were selected based on the most recent SB4 compositional projection, Case 15C Blend 1.3 Four different frits were included, based on previous assessments of projected operating windows and melt rate,4, 5 with four WLs selected for each frit. Eight of these frit-sludge combinations covered WLs which tightly bound the nepheline discriminator value of 0.62, with the intent of refining this value to a level of confidence where it can be incorporated into offline administrative controls and/or the Process Composition Control System (PCCS) to support Slurry Mix Evaporator (SME) acceptability decisions. The remaining eight frit-sludge combinations targeted lower WLs (35 and 40%) and were prepared and analyzed to contribute needed data to the ComPro database6 to support a potential variability study for SB4
Effects of Ag addition on solid–state interfacial reactions between Sn–Ag–Cu solder and Cu substrate

International Nuclear Information System (INIS)

Yang, Ming; Ko, Yong-Ho; Bang, Junghwan; Kim, Taek-Soo; Lee, Chang-Woo; Li, Mingyu

2017-01-01

Low–Ag–content Sn–Ag–Cu (SAC) solders have attracted much recent attention in electronic packaging for their low cost. To reasonably reduce the Ag content in Pb–free solders, a deep understanding of the basic influence of Ag on the SAC solder/Cu substrate interfacial reaction is essential. Previous studies have discussed the influence of Ag on the interfacial intermetallic compound (IMC) thickness. However, because IMC growth is the joint result of multiple factors, such characterizations do not reveal the actual role of Ag. In this study, changes in interfacial IMCs after Ag introduction were systemically and quantitatively characterized in terms of coarsening behaviors, orientation evolution, and growth kinetics. The results show that Ag in the solder alloy affects the coarsening behavior, accelerates the orientation concentration, and inhibits the growth of interfacial IMCs during solid–state aging. The inhibition mechanism was quantitatively discussed considering the individual diffusion behaviors of Cu and Sn atoms, revealing that Ag inhibits interfacial IMC growth primarily by slowing the diffusion of Cu atoms through the interface. - Highlights: •Role of Ag in IMC formation during Sn–Ag–Cu soldering was investigated. •Ag affects coarsening, crystallographic orientation, and IMC growth. •Diffusion pathways of Sn and Cu are affected differently by Ag. •Ag slows Cu diffusion to inhibit IMC growth at solder/substrate interface.
Effects of Ag addition on solid–state interfacial reactions between Sn–Ag–Cu solder and Cu substrate

Energy Technology Data Exchange (ETDEWEB)

Yang, Ming [Micro-Joining Center, Korea Institute of Industrial Technology (KITECH), Incheon 21999 (Korea, Republic of); Ko, Yong-Ho [Micro-Joining Center, Korea Institute of Industrial Technology (KITECH), Incheon 21999 (Korea, Republic of); Department of Mechanical Engineering, Korea Advanced Institute of Science and Technology (KAIST), 291, Daehak-ro, Yuseong-gu, Daejeon 34141 (Korea, Republic of); Bang, Junghwan [Micro-Joining Center, Korea Institute of Industrial Technology (KITECH), Incheon 21999 (Korea, Republic of); Kim, Taek-Soo [Department of Mechanical Engineering, Korea Advanced Institute of Science and Technology (KAIST), 291, Daehak-ro, Yuseong-gu, Daejeon 34141 (Korea, Republic of); Lee, Chang-Woo, E-mail: cwlee@kitech.re.kr [Micro-Joining Center, Korea Institute of Industrial Technology (KITECH), Incheon 21999 (Korea, Republic of); Li, Mingyu, E-mail: myli@hit.edu.cn [Shenzhen Key Laboratory of Advanced Materials, Harbin Institute of Technology Shenzhen Graduate School, Shenzhen 518055 (China)

2017-02-15

Low–Ag–content Sn–Ag–Cu (SAC) solders have attracted much recent attention in electronic packaging for their low cost. To reasonably reduce the Ag content in Pb–free solders, a deep understanding of the basic influence of Ag on the SAC solder/Cu substrate interfacial reaction is essential. Previous studies have discussed the influence of Ag on the interfacial intermetallic compound (IMC) thickness. However, because IMC growth is the joint result of multiple factors, such characterizations do not reveal the actual role of Ag. In this study, changes in interfacial IMCs after Ag introduction were systemically and quantitatively characterized in terms of coarsening behaviors, orientation evolution, and growth kinetics. The results show that Ag in the solder alloy affects the coarsening behavior, accelerates the orientation concentration, and inhibits the growth of interfacial IMCs during solid–state aging. The inhibition mechanism was quantitatively discussed considering the individual diffusion behaviors of Cu and Sn atoms, revealing that Ag inhibits interfacial IMC growth primarily by slowing the diffusion of Cu atoms through the interface. - Highlights: •Role of Ag in IMC formation during Sn–Ag–Cu soldering was investigated. •Ag affects coarsening, crystallographic orientation, and IMC growth. •Diffusion pathways of Sn and Cu are affected differently by Ag. •Ag slows Cu diffusion to inhibit IMC growth at solder/substrate interface.
Scalable Manufacturing of Solderable and Stretchable Physiologic Sensing Systems.

Science.gov (United States)

Kim, Yun-Soung; Lu, Jesse; Shih, Benjamin; Gharibans, Armen; Zou, Zhanan; Matsuno, Kristen; Aguilera, Roman; Han, Yoonjae; Meek, Ann; Xiao, Jianliang; Tolley, Michael T; Coleman, Todd P

2017-10-01

Methods for microfabrication of solderable and stretchable sensing systems (S4s) and a scaled production of adhesive-integrated active S4s for health monitoring are presented. S4s' excellent solderability is achieved by the sputter-deposited nickel-vanadium and gold pad metal layers and copper interconnection. The donor substrate, which is modified with "PI islands" to become selectively adhesive for the S4s, allows the heterogeneous devices to be integrated with large-area adhesives for packaging. The feasibility for S4-based health monitoring is demonstrated by developing an S4 integrated with a strain gauge and an onboard optical indication circuit. Owing to S4s' compatibility with the standard printed circuit board assembly processes, a variety of commercially available surface mount chip components, such as the wafer level chip scale packages, chip resistors, and light-emitting diodes, can be reflow-soldered onto S4s without modifications, demonstrating the versatile and modular nature of S4s. Tegaderm-integrated S4 respiration sensors are tested for robustness for cyclic deformation, maximum stretchability, durability, and biocompatibility for multiday wear time. The results of the tests and demonstration of the respiration sensing indicate that the adhesive-integrated S4s can provide end users a way for unobtrusive health monitoring. © 2017 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.
Multi-layer SiC ceramics/Mo joints brazed using high-temperature solders

International Nuclear Information System (INIS)

Olesinska, W.; Kesik, J.

2003-01-01

The paper presents the results of studies on joining SiC ceramics with molybdenum, with the ceramic surface being activated by titanium, chromium or copper. Titanium or chromium were deposited by the sputtering technique, and copper - by the electro-chemical method. The microstructures of the SiC/Mo joints brazed with the CuMn13Ni3 solder and copper in a nitrogen atmosphere were examined and the results discussed. The joints, in which the ceramic surface was activated in addition with chromium, do not contain mechanical defects caused by the joining process, and the ceramic surface is covered with a continuous layer of the solder. A phase analysis of the interface surface identified an MeSiC phase. The mechanical strength of the joints in which the ceramic surface was modified by the Ti, Cr and Cu layers was markedly greater than that of the joints brazed directly to the uncoated ceramics with the use of active solders. (author)
The effect of intermetallic compound morphology on Cu diffusion in Sn-Ag and Sn-Pb solder bump on the Ni/Cu Under-bump metallization

Science.gov (United States)

Jang, Guh-Yaw; Duh, Jenq-Gong

2005-01-01

The eutectic Sn-Ag solder alloy is one of the candidates for the Pb-free solder, and Sn-Pb solder alloys are still widely used in today’s electronic packages. In this tudy, the interfacial reaction in the eutectic Sn-Ag and Sn-Pb solder joints was investigated with an assembly of a solder/Ni/Cu/Ti/Si3N4/Si multilayer structures. In the Sn-3.5Ag solder joints reflowed at 260°C, only the (Ni1-x,Cux)3Sn4 intermetallic compound (IMC) formed at the solder/Ni interface. For the Sn-37Pb solder reflowed at 225°C for one to ten cycles, only the (Ni1-x,Cux)3Sn4 IMC formed between the solder and the Ni/Cu under-bump metallization (UBM). Nevertheless, the (Cu1-y,Niy)6Sn5 IMC was observed in joints reflowed at 245°C after five cycles and at 265°C after three cycles. With the aid of microstructure evolution, quantitative analysis, and elemental distribution between the solder and Ni/Cu UBM, it was revealed that Cu content in the solder near the solder/IMC interface played an important role in the formation of the (Cu1-y,Niy)6Sn5 IMC. In addition, the diffusion behavior of Cu in eutectic Sn-Ag and Sn-Pb solders with the Ni/Cu UBM were probed and discussed. The atomic flux of Cu diffused through Ni was evaluated by detailed quantitative analysis in an electron probe microanalyzer (EPMA). During reflow, the atomic flux of Cu was on the order of 1016-1017 atoms/cm2sec in both the eutectic Sn-Ag and Sn-Pb systems.
Comparison between mixed and spatially separated remote phosphor fabricated via a screen-printing process

Science.gov (United States)

Kim, Byung-Ho; Hwang, Jonghee; Lee, Young Jin; Kim, Jin-Ho; Jeon, Dae-Woo; Lee, Mi Jai

2016-08-01

We developed a fabrication method for remote phosphor by a screen-printing process, using green phosphor, red phosphor, and thermally stable glass frit. The glass frit was introduced for long-term stability. The optical properties of the remote phosphor were observed via an integrating sphere; the photoluminescence spectrum dramatically changed on incorporating a minor amount of the red phosphor. These unique optical properties were elucidated using four factors: phosphor ratio, scattering induced by packing density, light intensity per unit volume, and reabsorption. The thermal stability of the remote phosphor was investigated at 500°C, demonstrating its outstanding thermal properties.

Effect of trace elements on the interface reactions between two lead-free solders and copper or nickel substrates

Directory of Open Access Journals (Sweden)

Soares D.

2007-01-01

Full Text Available Traditional Sn-Pb solder alloys are being replaced, because of environmental and health concerns about lead toxicity. Among some alternative alloy systems, the Sn-Zn and Sn-Cu base alloy systems have been studied and reveal promising properties. The reliability of a solder joint is affected by the solder/substrate interaction and the nature of the layers formed at the interface. The solder/substrate reactions, for Sn-Zn and Sn-Cu base solder alloys, were evaluated in what concerns the morphology and chemical composition of the interface layers. The effect of the addition of P, at low levels, on the chemical composition of the layers present at the interface was studied. The phases formed at the interface between the Cu or Ni substrate and a molten lead-free solder at 250ºC, were studied for different stage times and alloy compositions. The melting temperatures, of the studied alloys, were determined by Differential Scanning Calorimetry (DSC. Identification of equilibrium phases formed at the interface layer, and the evaluation of their chemical composition were performed by Scanning Electron Microscopy (SEM/EDS. Different interface characteristics were obtained, namely for the alloys containing Zn. The obtained IML layer thickness was compared, for both types of alloy systems.
Development of Pb-Free Nanocomposite Solder Alloys

Directory of Open Access Journals (Sweden)

Animesh K. Basak

2018-04-01

Full Text Available As an alternative to conventional Pb-containing solder material, Sn–Ag–Cu (SAC based alloys are at the forefront despite limitations associated with relatively poor strength and coarsening of grains/intermetallic compounds (IMCs during aging/reflow. Accordingly, this study examines the improvement of properties of SAC alloys by incorporating nanoparticles in it. Two different types of nanoparticles were added in monolithic SAC alloy: (1 Al2O3 or (2 Fe and their effect on microstructure and thermal properties were investigated. Addition of Fe nanoparticles leads to the formation of FeSn2 IMCs alongside Ag3Sn and Cu6Sn5 from monolithic SAC alloy. Addition of Al2O3 nano-particles do not contribute to phase formation, however, remains dispersed along primary β-Sn grain boundaries and act as a grain refiner. As the addition of either Fe or Al2O3 nano-particles do not make any significant effect on thermal behavior, these reinforced nanocomposites are foreseen to provide better mechanical characteristics with respect to conventional monolithic SAC solder alloys.
A Feasibility Study of Lead Free Solders for Level 1 Packaging Applications

DEFF Research Database (Denmark)

Chidambaram, Vivek; Hald, John; Hattel, Jesper Henri

2009-01-01

An attempt has been made to determine the lead free ternary combinations that satisfied the solidification requirement for a solder used in level 1 packaging applications, using the CALPHAD approach. The segregation profiles of the promising candidates were analyzed after scrutinizing the equilib......An attempt has been made to determine the lead free ternary combinations that satisfied the solidification requirement for a solder used in level 1 packaging applications, using the CALPHAD approach. The segregation profiles of the promising candidates were analyzed after scrutinizing...
Microstructural effects on constitutive and fatigue fracture behavior of TinSilverCopper solder

Science.gov (United States)

Tucker, Jonathon P.

As microelectronic package construction becomes more diverse and complex, the need for accurate, geometry-independent material constitutive and failure models increases. Evaluations of packages based on accelerated environmental tests (such as accelerated thermal cycling or power cycling) only provide package-dependent reliability information. In addition, extrapolations of such test data to life predictions under field conditions are often empirical. Besides geometry, accelerated environmental test data must account for microstructural factors such as alloy composition or isothermal aging condition, resulting in expensive experimental variation. In this work, displacement-controlled, creep, and fatigue lap shear tests are conducted on specially designed SnAgCu test specimens with microstructures representative to those found in commercial microelectronic packages. The data are used to develop constitutive and fatigue fracture material models capable of describing deformation and fracture behavior for the relevant temperature and strain rate ranges. Furthermore, insight is provided into the microstructural variation of solder joints and the subsequent effect on material behavior. These models are appropriate for application to packages of any geometrical construction. The first focus of the thesis is on Pb-mixed SnAgCu solder alloys. During the transition from Pb-containing solders to Pb-free solders, joints composed of a mixture of SnPb and SnAgCu often result from either mixed assemblies or rework. Three alloys of 1, 5 and 20 weight percent Pb were selected so as to represent reasonable ranges of Pb contamination expected from different 63Sn37Pb components mixed with Sn3.0Ag0.5Cu. Displacement-controlled (constant strain rate) and creep tests were performed at temperatures of 25°C, 75°C, and 125°C using a double lap shear test setup that ensures a nearly homogeneous state of plastic strain at the joint interface. Rate-dependent constitutive models for Pb
Effect of zircon-based tricolor pigments on the color, microstructure, flexural strength and translucency of a novel dental lithium disilicate glass-ceramic.

Science.gov (United States)

Yuan, Kun; Wang, Fu; Gao, Jing; Sun, Xiang; Deng, Zai-Xi; Wang, Hui; Jin, Lei; Chen, Ji-Hua

2014-01-01

The purpose of this study was to investigate the effect of zircon-based tricolor pigments (praseodymium zircon yellow, ferrum zircon red, and vanadium zircon blue) on the color, thermal property, crystalline phase composition, microstructure, flexural strength, and translucency of a novel dental lithium disilicate glass-ceramic. The pigments were added to the glass frit, milled, pressed, and sintered. Ninety monochrome samples were prepared and the colors were analyzed. The effect of the pigments on thermal property, crystalline phase composition, and microstructure were determined by differential scanning calorimetry (DSC), X-ray diffraction (XRD), and scanning electron microscopy (SEM), respectively. Addition of the pigments resulted in the acquisition of subtractive primary colors as well as tooth-like colors, and did not demonstrate significant effects on the thermal property, crystalline phase composition, microstructure, and flexural strength of the experimental glass-ceramic. Although significant differences (p ceramics, the translucencies of the latter were sufficient to fabricate dental restorations. These results indicate that the zircon-based tricolor pigments can be used with dental lithium disilicate glass-ceramic to produce abundant and predictable tooth-like colors without significant adverse effects, if mixed in the right proportions. Copyright © 2013 Wiley Periodicals, Inc.
Design and Experiment of a Solder Paste Jetting System Driven by a Piezoelectric Stack

Directory of Open Access Journals (Sweden)

Shoudong Gu

2016-06-01

Full Text Available To compensate for the insufficiency and instability of solder paste dispensing and printing that are used in the SMT (Surface Mount Technology production process, a noncontact solder paste jetting system driven by a piezoelectric stack based on the principle of the nozzle-needle-system is introduced in this paper, in which a miniscule gap exists between the nozzle and needle during the jetting process. Here, the critical jet ejection velocity is discussed through theoretical analysis. The relations between ejection velocity and needle structure, needle velocity, and nozzle diameter were obtained by FLUENT software. Then, the prototype of the solder paste jetting system was fabricated, and the performance was verified by experiments. The effects of the gap between nozzle and needle, the driving voltage, and the nozzle diameter on the jetting performance and droplet diameter were obtained. Solder paste droplets 0.85 mm in diameter were produced when the gap between the nozzle and needle was adjusted to 10 μm, the driving voltage to 80 V, the nozzle diameter to 0.1 mm, and the variation of the droplet diameter was within ±3%.
Decomposition of no-clean solder flux systems and their effects on the corrosion reliability of electronics

DEFF Research Database (Denmark)

Conseil, Helene; Verdingovas, Vadimas; Jellesen, Morten Stendahl

2016-01-01

No-clean flux systems are used today for the soldering of electronic printed circuit board assemblies assuming that all the aggressive substances of the flux will vanish during the soldering process i.e. evaporate, decompose or being enclosed safely in the residues. However this is not true in most...... that the fluxes do not decompose fully within the temperature regime of the soldering process, leaving behind significant level of weak organic acid residues. The residue depending on the type and amount can be can be very aggressive towards the corrosion on the printed circuit board assemblies. The glutaric acid...
Comparative Study of ENIG and ENEPIG as Surface Finishes for a Sn-Ag-Cu Solder Joint

Science.gov (United States)

Yoon, Jeong-Won; Noh, Bo-In; Jung, Seung-Boo

2011-09-01

Interfacial reactions and joint reliability of Sn-3.0Ag-0.5Cu solder with two different surface finishes, electroless nickel-immersion gold (ENIG) and electroless nickel-electroless palladium-immersion gold (ENEPIG), were evaluated during a reflow process. We first compared the interfacial reactions of the two solder joints and also successfully revealed a connection between the interfacial reaction behavior and mechanical reliability. The Sn-Ag-Cu/ENIG joint exhibited a higher intermetallic compound (IMC) growth rate and a higher consumption rate of the Ni(P) layer than the Sn-Ag-Cu/ENEPIG joint. The presence of the Pd layer in the ENEPIG suppressed the growth of the interfacial IMC layer and the consumption of the Ni(P) layer, resulting in the superior interfacial stability of the solder joint. The shear test results show that the ENIG joint fractured along the interface, exhibiting indications of brittle failure possibly due to the brittle IMC layer. In contrast, the failure of the ENEPIG joint only went through the bulk solder, supporting the idea that the interface is mechanically reliable. The results from this study confirm that the Sn-Ag-Cu/ENEPIG solder joint is mechanically robust and, thus, the combination is a viable option for a Pb-free package system.
In-vitro Investigations of Skin Closure using Diode Laser and Protein Solder Containing Gold Nanoshells

Directory of Open Access Journals (Sweden)

Mohammad Sadegh Nourbakhsh

2010-12-01

Full Text Available Introduction: Laser tissue soldering is a new technique for repair of various tissues including the skin, liver, articular cartilage and nerves and is a promising alternative to suture. To overcome the problems of thermal damage to surrounding tissues and low laser penetration depth, some exogenous chromophores such as gold nanoshells, a new class of nanoparticles consisting of a dielectric core surrounded by a thin metal shell, are used. The aims of this study were to use two different concentrations of gold nanoshells as the exogenous material for skin tissue soldering and also to examine the effects of laser soldering parameters on the properties of the repaired skin. Material and Methods: Two mixtures of albumin solder and different concentrations of gold nanoshells were prepared. A full thickness incision of 2×20 mm2 was made on the surface and after placing 50 μl of the solder mixture on the incision, an 810 nm diode laser was used to irradiate it at different power densities. The changes of tensile strength, σt, due to temperature rise, number of scan (Ns, and scan velocity (Vs were investigated. Results: The results showed that the tensile strength of the repaired skin increased with increasing irradiance for both gold nanoshell concentrations. In addition, at constant laser irradiance (I, the tensile strength of the repaired incision increased with increasing Ns and decreasing Vs. In our case, this corresponded to st = 1610 g/cm2 at I ~ 60 Wcm-2, T ~ 65ºC, Ns = 10 and Vs = 0.2 mms-1. Discussion and Conclusion: Gold nanoshells can be used as an indocyanine green dye (ICG alterative for laser tissue soldering. Although by increasing the laser power density, the tensile strength of the repaired skin increases, an optimum power density must be considered due to the resulting increase in tissue temperature.
Incorporation of Interfacial Intermetallic Morphology in Fracture Mechanism Map for Sn-Ag-Cu Solder Joints

Science.gov (United States)

Huang, Z.; Kumar, P.; Dutta, I.; Sidhu, R.; Renavikar, M.; Mahajan, R.

2014-01-01

A fracture mechanism map (FMM) is a powerful tool which correlates the fracture behavior of a material to its microstructural characteristics in an explicit and convenient way. In the FMM for solder joints, an effective thickness of the interfacial intermetallic compound (IMC) layer ( t eff) and the solder yield strength ( σ ys,eff) are used as abscissa and ordinate axes, respectively, as these two predominantly affect the fracture behavior of solder joints. Earlier, a definition of t eff, based on the uniform thickness of IMC ( t u) and the average height of the IMC scallops ( t s), was proposed and shown to aptly explain the fracture behavior of solder joints on Cu. This paper presents a more general definition of t eff that is more widely applicable to a range of metallizations, including Cu and electroless nickel immersion gold (ENIG). Using this new definition of t eff, mode I FMM for SAC387/Cu joints has been updated and its validity was confirmed. A preliminary FMM for SAC387/Cu joints with ENIG metallization is also presented.
THE POSSIBILITY OF USING LASER-ULTRASOUND TO MONITOR THE QUALITY SOLDERED CONNECTIONS CHAMBERS OF LIQUID ROCKET ENGINES

Directory of Open Access Journals (Sweden)

N. V. Astredinova

2014-01-01

Full Text Available During the manufacturing process to the design of modern liquid rocket engines are presented important requirements, such as minimum weight, maximum stiffness and strength of nodes, maximum service life in operation, high reliability and quality of soldered and welded seams. Due to the high quality requirements soldered connections and the specific design of the nozzle, it became necessary in the development and testing of a new non-conventional non-destructive testing method – laser-ultrasound diagnosis. In accordance with regulatory guidelines, quality control soldered connections is allowed to use an acoustic kind of control methods of the reflected light, transmitted light, resonant, free vibration and acoustic emission. Attempts to use traditional methods of non-destructive testing did not lead to positive results. This is due primarily to the size of typical solder joint defects, as well as the structural features of the rocket engine, the data structure is not controllable. In connection with this, a new method that provides quality control soldered connections cameras LRE based on the thermo generation of ultrasound. Methods of ultrasonic flaw detection of photoacoustic effect, in most cases, have a number of advantages over methods that use standard (traditional piezo transducers. In the course of studies have found that the sensitivity of the laser-ultrasonic method and flaw detector UDL-2M can detect lack of adhesion in the solder joints on the upper edges of the nozzle in the sub-header area of the site.
Standard test method for linear thermal expansion of glaze frits and ceramic whiteware materials by the interferometric method

CERN Document Server

American Society for Testing and Materials. Philadelphia

1995-01-01

1.1 This test method covers the interferometric determination of linear thermal expansion of premelted glaze frits and fired ceramic whiteware materials at temperatures lower than 1000°C (1830°F). 1.2 This standard does not purport to address all of the safety concerns, if any, associated with its use. It is the responsibility of the user of this standard to establish appropriate safety and health practices and determine the applicability of regulatory limitations prior to use.
Radioactive waste combustion-vitrification under arc plasma: thermal and dynamic modelling

International Nuclear Information System (INIS)

Barthelemy, B.

2003-06-01

This thesis concerns the thermal and dynamic modelling for a combustion/vitrification process of surrogate radioactive waste under transferred arc plasma. The writer presents the confinement processes for radioactive waste using arc plasma and the different software used to model theses processes. This is followed by a description of our experimental equipment including a plasma arc reactor and an inductive system allowing the homogenization of glass temperature. A combustion/vitrification test is described. Thermal and material balances were discussed. The temperature fields of plasma arc and the glass frit conductivity are measured. Finally, the writer describes and clarifies the equations solved for the simulations of the electrically plasma arc and the glass melting including the thin layer of glass frit coating the crucible cold walls. The modelling results are presented in the form of spatial distribution of temperature, velocity and voluminal power... (author)
Radioactive waste combustion / vitrification under arc plasma: thermal and dynamic modelling

International Nuclear Information System (INIS)

Barthelemy, B.

2003-01-01

This thesis concerns the thermal and dynamic modelling for a combustion/vitrification process of surrogate radioactive waste under transferred arc plasma. The writer presents the confinement processes for radioactive waste using arc plasma and the different software used to model theses processes. This is followed by a description of our experimental equipment including a plasma arc reactor and an inductive system allowing the homogenization of glass temperature. A combustion/vitrification test is described. Thermal and material balances were discussed. The temperature fields of plasma arc and the glass frit conductivity are measured. Finally, the writer describes and clarifies the equations solved for the simulations of the electrically plasma arc and the glass melting including the thin layer of glass frit coating the crucible cold walls. The modelling results are presented in the form of spatial distribution of temperature, velocity and volume power... (author)
Radioactive waste combustion / vitrification under arc plasma: thermal and dynamic modelling; Combustion - vitrification de dechets radioactifs par plasma d'arc: modelisation de la thermique et de la dynamique

Energy Technology Data Exchange (ETDEWEB)

Barthelemy, B

2003-07-01

This thesis concerns the thermal and dynamic modelling for a combustion/vitrification process of surrogate radioactive waste under transferred arc plasma. The writer presents the confinement processes for radioactive waste using arc plasma and the different software used to model theses processes. This is followed by a description of our experimental equipment including a plasma arc reactor and an inductive system allowing the homogenization of glass temperature. A combustion/vitrification test is described. Thermal and material balances were discussed. The temperature fields of plasma arc and the glass frit conductivity are measured. Finally, the writer describes and clarifies the equations solved for the simulations of the electrically plasma arc and the glass melting including the thin layer of glass frit coating the crucible cold walls. The modelling results are presented in the form of spatial distribution of temperature, velocity and volume power... (author)
Radioactive waste combustion-vitrification under arc plasma: thermal and dynamic modelling; Combustion - vitrification de dechets radioactifs par plasma d'arc: modelisation de la thermique et de la dynamique

Energy Technology Data Exchange (ETDEWEB)

Barthelemy, B

2003-06-01

This thesis concerns the thermal and dynamic modelling for a combustion/vitrification process of surrogate radioactive waste under transferred arc plasma. The writer presents the confinement processes for radioactive waste using arc plasma and the different software used to model theses processes. This is followed by a description of our experimental equipment including a plasma arc reactor and an inductive system allowing the homogenization of glass temperature. A combustion/vitrification test is described. Thermal and material balances were discussed. The temperature fields of plasma arc and the glass frit conductivity are measured. Finally, the writer describes and clarifies the equations solved for the simulations of the electrically plasma arc and the glass melting including the thin layer of glass frit coating the crucible cold walls. The modelling results are presented in the form of spatial distribution of temperature, velocity and voluminal power... (author)
Hypospadias repair using laser tissue soldering (LTS): preliminary results of a prospective randomized study

Science.gov (United States)

Kirsch, Andrew J.; Cooper, Christopher S.; Canning, Douglas A.; Snyder, Howard M., III; Zderic, Stephen A.

1998-07-01

Purpose: The purpose of this study was to evaluate laser tissue soldering using an 808 nm diode laser and wavelength- matched human albumin solder for urethral surgery in children. Methods: Currently, 30 boys, ages 3 months to 8 years were randomized to standard suturing (n equals 22) or 'sutureless' laser hypospadias repair (n equals 18). Laser soldering was performed with a human albumin solder doped with indocyanine green dye (2.5 mg/ml) using a laser power output of 0.5 W, pulse duration of 0.5 sec, and interval of 0.1 sec. Power density was approximately 16 W/cm2. In the laser group, sutures were used for tissue alignment only. At the time of surgery, neourethral and penile lengths, operative time for urethral repair, and number of sutures/throws were measured. Postoperatively, patients were examined for complications of wound healing, stricture, or fistula formation. Results: Mean age, severity of urethral defect, type of repair, and neourethra length were equivalent between the two groups. Operative time was significantly faster for laser soldering in both simple (1.6 plus or minus 0.21 min, p less than 0.001) and complex (5.4 plus or minus 0.28 min, p less than 0.0001) hypospadias repairs compared to controls (10.6 plus or minus 1.4 min and 27.8 plus or minus 2.9 min, respectively). The mean number of sutures used in the laser group for simple and complex repairs (3.3 plus or minus 0.3 and 8.1 plus or minus 0.64, respectively) were significantly (p less than 0.0001) less than for controls (8.2 plus or minus 0.84 and 20 plus or minus 2.3, respectively). Followup was between 3 months and 14 months. The overall complication rate in the laser group (11%) was lower than the controls (23%). However, statistical significance (p less than 0.05) was achieved only for the subgroup of patients undergoing simple repairs (LTS, 100% success versus suturing, 69% success). Conclusions: These preliminary results indicate that laser tissue soldering for hypospadias repair
Production of sodalite waste forms by addition of glass

International Nuclear Information System (INIS)

Pereira, C.

1995-01-01

Spent nuclear fuel can be treated in a molten salt electrorefiner for conversion into metal and mineral waste forms for geologic disposal. Sodalite is one of the mineral waste forms under study. Fission products in the molten salt are ion-exchanged into zeolite A, which is converted to sodalite and consolidated. Sodalite can be formed directly from mixtures of salt and zeolite A at temperatures above 975 K; however, nepheline is usually produced as a secondary phase. Addition of small amounts of glass frit to the mixture reduced nepheline formation significantly. Loss of fission products was not observed for reaction below 1000 K. Hot-pressing of the sodalite powders yielded dense pellets (∼2.3 g/cm 3 ) without any loss of fission product species. Normalized release rates were below 1 g/m 2 ·day for pre-washed samples in 28-day leach tests based on standard MCC-1 tests but increased with the presence of free salt on the sodalite
Effects of aging time on the mechanical properties of Sn–9Zn–1.5Ag–xBi lead-free solder alloys

International Nuclear Information System (INIS)

Liu, Chih-Yao; Hon, Min-Hsiung; Wang, Moo-Chin; Chen, Ying-Ru; Chang, Kuo-Ming; Li, Wang-Long

2014-01-01

Highlights: • The microstructure of these solder alloys are composed of Sn-rich phase and Ag 3 Sn. • The grain size of Sn–9Zn–1.5Ag–xBi solder alloys increases with rose aging time. • The maximum yield strength is 112.7 ± 2.2 MPa for Sn–9Zn–1.5Ag–3Bi solder alloys. • TEM observed that Bi appears as oblong shape fine particles. -- Abstract: The effects of aging time on the mechanical properties of the Sn–9Zn–1.5Ag–xBi lead-free solder alloys are investigated using scanning electron microscopy (SEM), X-ray diffraction (XRD), transmission electron microscopy (TEM), selected area electron diffraction (SAED), energy dispersive spectrometry (EDS) and a universal testing machine. The experimental results show that the microstructure of Sn–9Zn–1.5Ag–xBi solder alloys is composed of Sn-rich phase and AgZn 3 . No other intermetallic compounds (IMCs) with Bi content was observed in the solder matrix for Sn–9Zn–1.5Ag solder alloys with various Bi contents before and after aging at 150 °C for different durations. The lattice parameter increases significantly with increasing aging time or Bi addition. The size of Sn-rich grain increased gradually with aging time increased, but decreases with Bi content increases. The maximum yield strength is 112.7 ± 2.2 MPa for Sn–9Zn–1.5Ag–3Bi solder alloy before aging
Effects of aging time on the mechanical properties of Sn–9Zn–1.5Ag–xBi lead-free solder alloys

Energy Technology Data Exchange (ETDEWEB)

Liu, Chih-Yao [Department of Materials Science and Engineering, National Cheng Kung University, 1 Ta-Hsueh Road, Tainan 70101, Taiwan (China); Hon, Min-Hsiung [Department of Materials Science and Engineering, National Cheng Kung University, 1 Ta-Hsueh Road, Tainan 70101, Taiwan (China); Department of Mechanical Engineering, National Kaohsiung University of Applied Sciences, 415 Chien-Kung Road, Kaohsiung 80782, Taiwan (China); Wang, Moo-Chin, E-mail: mcwang@kmu.edu.tw [Department of Fragrance and Cosmetic Science, Kaohsiung Medical University, 100, Shih-Chuan 1st Road, Kaohsiung 80728, Taiwan (China); Chen, Ying-Ru; Chang, Kuo-Ming; Li, Wang-Long [Institute of Nanotechnology and Microsystems Engineering, National Cheng Kung University, No. 1, University Road, Tainan 70101, Taiwan (China)

2014-01-05

Highlights: • The microstructure of these solder alloys are composed of Sn-rich phase and Ag{sub 3}Sn. • The grain size of Sn–9Zn–1.5Ag–xBi solder alloys increases with rose aging time. • The maximum yield strength is 112.7 ± 2.2 MPa for Sn–9Zn–1.5Ag–3Bi solder alloys. • TEM observed that Bi appears as oblong shape fine particles. -- Abstract: The effects of aging time on the mechanical properties of the Sn–9Zn–1.5Ag–xBi lead-free solder alloys are investigated using scanning electron microscopy (SEM), X-ray diffraction (XRD), transmission electron microscopy (TEM), selected area electron diffraction (SAED), energy dispersive spectrometry (EDS) and a universal testing machine. The experimental results show that the microstructure of Sn–9Zn–1.5Ag–xBi solder alloys is composed of Sn-rich phase and AgZn{sub 3}. No other intermetallic compounds (IMCs) with Bi content was observed in the solder matrix for Sn–9Zn–1.5Ag solder alloys with various Bi contents before and after aging at 150 °C for different durations. The lattice parameter increases significantly with increasing aging time or Bi addition. The size of Sn-rich grain increased gradually with aging time increased, but decreases with Bi content increases. The maximum yield strength is 112.7 ± 2.2 MPa for Sn–9Zn–1.5Ag–3Bi solder alloy before aging.

Effect of the Molar Ratio of B2O3 to Bi2O3 in Al Paste with Bi2O3-B2O3-ZnO Glass on Screen Printed Contact Formation and Si Solar Cell Performance

Science.gov (United States)

Kim, Bit-Na; Kim, Hyeong Jun; Chang, Hyo Sik; Hong, Hyun Seon; Ryu, Sung-Soo; Lee, Heon

2013-10-01

In this study, eco-friendly Pb-free Bi2O3-B2O3-ZnO glass frits were chosen as an inorganic additive for the Al paste used in Si solar cells. The effects of the molar ratio of Bi2O3 to B2O3 in the glass composition on the electrical resistance of the Al electrode and on the cell performance were investigated. The results showed that as the molar ratio of Bi2O3 to B2O3 increased, the glass transition temperature and softening temperature decreased because of the reduced glass viscosity. In Al screen-printed Si solar cells, as the molar ratio of Bi2O3 to B2O3 increased, the sheet electrical resistance of the Al electrode decreased and the cell efficiency increased. The uniformity and thickness of the back-surface field was significantly influenced by the glass composition.
Immobilization of high level nuclear wastes in sintered glasses. Devitrification evaluation produced with different thermal treatments

International Nuclear Information System (INIS)

Messi de Bernasconi, N.B.; Russo, D.O.; Bevilacqua, M.E.; Sterba, M.E.; Heredia, A.D.; Audero, M.A.

1990-01-01

This work describes immobilization of high level nuclear wastes in sintered glass, as alternative way to melting glass. Different chemical compositions of borosilicate glass with simulate waste were utilized and satisfactory results were obtained at laboratory scale. As another contribution to the materials studies by X ray powder diffraction analysis, the devitrification produced with different thermal treatments, was evaluated. The effect of the thermal history on the behaviour of fission products containing glasses has been studied by several working groups in the field of high level waste fixation. When the glass is cooled through the temperature range from 800 deg C down to less than 400 deg C (these temperatures are approximates) nucleation and crystal growth can take place. The rate of crystallization will be maximum near the transformation point but through this rate may be low at lower temperatures, devitrification can still occur over long periods of time, depending on the glass composition. It was verified that there can be an appreciable increase in leaching in some waste glass compositions owing to the presence of crystalline phases. On the other hand, other compositions show very little change in leachability and the devitrified product is often preferable as there is less tendency to cracking, particularly in massive blocks of glass. A borosilicate glass, named SG7, which was developed specially in the KfK for the hot pressing of HLW with glass frit was studied. It presents a much enhanced chemical durability than borosolicate glass developed for the melting process. The crystallization behaviour of SG7 glass products was investigated in our own experiments by annealing sintered samples up to 3000 h at temperatures between 675 and 825 deg C. The samples had contained simulated waste with noble metals, since these might act as foreign nuclei for crystallization. Results on the extent of devitrification and time- temperature- transformation curves are
Effect of different glass and zeolite A compositions on the leach resistance of ceramic waste forms

International Nuclear Information System (INIS)

Lewis, M.A.; Hash, M.; Glandorf, D.

1996-01-01

A ceramic waste form is being developed for waste generated during electrometallurgical treatment of spent nuclear fuel. The waste is generated when fission products are removed from the electrolyte, LiCl-KCl eutectic. The waste form is a composite fabricated by hot isostatic pressing a mixture of glass frit and zeolite occluded with fission products and salt. Normalized release rate is less than 1 g/m 2 d for all elements in MCC-1 leach test run for 28 days in deionized water at 90 C. This leach resistance is comparable to that of early Savannah River glasses. We are investigating how leach resistance is affected by changes in cationic form of zeolite and in glass composition. Composites were made with 3 forms of zeolite A and 6 glasses. We used 3-day ASTM C1220-92 (formerly MCC-1) leach tests to screen samples for development purposes only. The leach test results show that the glass composites of zeolites 5A and 4A retain fission products equally well. Loss of Cs is small (0.1-0.5 wt%), while the loss of divalent and trivalent fission products is one or more orders of magnitude smaller. Composites of 5A retain chloride ion better in these short-term screens than 4A and 3A. The more leach resistant composites were made with durable glasses rich in silica and poor in alkaline earth oxides. XRD show that a salt phase was absent in the leach resistant composites of 5A and the better glasses but was present in the other composites with poorer leach performance. Thus, absence of salt phase corresponds to improved leach resistance. Interactions between zeolite and glass depend on composition of both
Thermal Fatigue Evaluation of Pb-Free Solder Joints: Results, Lessons Learned, and Future Trends

Science.gov (United States)

Coyle, Richard J.; Sweatman, Keith; Arfaei, Babak

2015-09-01

Thermal fatigue is a major source of failure of solder joints in surface mount electronic components and it is critically important in high reliability applications such as telecommunication, military, and aeronautics. The electronic packaging industry has seen an increase in the number of Pb-free solder alloy choices beyond the common near-eutectic Sn-Ag-Cu alloys first established as replacements for eutectic SnPb. This paper discusses the results from Pb-free solder joint reliability programs sponsored by two industry consortia. The characteristic life in accelerated thermal cycling is reported for 12 different Pb-free solder alloys and a SnPb control in 9 different accelerated thermal cycling test profiles in terms of the effects of component type, accelerated thermal cycling profile and dwell time. Microstructural analysis on assembled and failed samples was performed to investigate the effect of initial microstructure and its evolution during accelerated thermal cycling test. A significant finding from the study is that the beneficial effect of Ag on accelerated thermal cycling reliability (measured by characteristic lifetime) diminishes as the severity of the accelerated thermal cycling, defined by greater ΔT, higher peak temperature, and longer dwell time increases. The results also indicate that all the Pb-free solders are more reliable in accelerated thermal cycling than the SnPb alloy they have replaced. Suggestions are made for future work, particularly with respect to the continued evolution of alloy development for emerging application requirements and the value of using advanced analytical methods to provide a better understanding of the effect of microstructure and its evolution on accelerated thermal cycling performance.
Effects of PCB thickness on adjustable fountain wave soldering

Indian Academy of Sciences (India)

hybrid circuit assembly, component lead tinning, and wire tinning. .... The mesh model was built and optimized with 599920 hybrid nodes as shown in figure 9. ... conducted to track the fluid motions of the two phases (i.e., molten solder and air).
Influencia de la molienda en la energía superficial de fritas para esmaltes

Directory of Open Access Journals (Sweden)

Tamayo, A.

2013-04-01

Full Text Available In this work has been studied the influence of the milling process of two ceramic frits used in the ceramic tile industry. Both glass frits were of similar chemical composition changing SiO2 by 5% of B2O3 and both of them were water or dry milled. Glass frit surfaces were characterized by FT-IR, Karl-Fischer (K-F titration and Inverse Gas Chromatography at Infinite Dilution (IGC-ID. By K-F titration it was observed that water milled frits presented 28 and 26 OH groups for 100 A2 if they do not contain or contain boron, respectively. These surface changes are also observed by IGC-ID. Thus, the glass frit without boron and dry milled presented the highest dispersive surface energy (44 mJ.m-2 and the less acidic constant (0.13 kJ.mol-1. Both glass frits are amphoteric with acidic and base surface active sites, and that frit without boron presents the higher basicity. Milling process influences in the acid-base surface characteristics of both frits by increasing the basicity for the one without boron and increasing for the other one. This has been assigned to the different location of hydroxyl groups where the higher interaction is the one that does not contain boron and dry milled as K-F results.Se ha estudiado el proceso de molienda en dos fritas de la industria cerámica. Las dos fritas, de composiciones similares pero en una se ha sustituido parte de la sílice por 5% de óxido de boro, fueron molidas por vía seca o húmeda y se caracterizaron mediante FT-IR, valoración Karl-Fischer e IGC-ID. Mediante valoración se han determinado los contenidos en moléculas de agua e hidroxilos. El mayor contenido en hidroxilos lo posee la frita sin boro seguida de la de boro ambas molidas en húmedo, poseyendo 28 y 26 grupos OH por cada 100 A2, respectivamente. Estos resultados coinciden con IGC-ID, sin embargo es la frita sin boro molida en seco la de mayor energía superficial (44 mJ.m-2 y constante ácida (0.13 kJ.mol-1. Aunque las dos fritas tienen
Glass-Ceramic Material from the SiO{sub 2}-Al{sub 2}O{sub 3}-CaO System Using Sugar-Cane Bagasse Ash (SCBA)

Energy Technology Data Exchange (ETDEWEB)

Teixeira, S R; Magalhaes, R S; Souza, A E; Santos, G T A; Silva, R A [Universidade Estadual Paulista - Unesp/FCT - Presidente Prudente, SP (Brazil); Romero, M; Ma Rincon, J, E-mail: rainho@fct.unesp.br [Instituto Eduardo Torroja de Ciencias de la Construccion - IETCC/CSIC, Madrid (Spain)

2011-10-29

Brazil is the world's largest producer of alcohol and sugar from sugarcane. Currently, sugarcane bagasse is burned in boilers to produce steam and electrical energy, producing a huge volume of ash. The major component of the ash is SiO{sub 2}, and among the minor components there are some mineralizing agents or fluxing. Published works have shown the potential of transforming silicate-based residues into glass-ceramic products of great utility. This work reports the research results of SCBA use to produce glass-ceramics with wollastonite, rankinite and gehlenite as the major phases. These silicates have important applications as building industry materials, principally wollastonite, due to their special properties: high resistance to weathering, zero water absorption, and hardness among others. The glasses (frits) were prepared mixing ash, calcium carbonate and sodium or potassium carbonates as flux agents, in different concentrations. X-ray fluorescence was used to determine the chemical composition of the glasses and their crystallization was assessed by using thermal analysis (DTA/DSC/TGA) and X-ray diffraction. The crystallization kinetics was evaluated using the Kissinger method, giving activation energies ranging from 200 to 600 kJ/mol.
Influence of nanoparticle addition on the formation and growth of intermetallic compounds (IMCs) in Cu/Sn–Ag–Cu/Cu solder joint during different thermal conditions

International Nuclear Information System (INIS)

Ting Tan, Ai; Wen Tan, Ai; Yusof, Farazila

2015-01-01

Nanocomposite lead-free solders are gaining prominence as replacements for conventional lead-free solders such as Sn–Ag–Cu solder in the electronic packaging industry. They are fabricated by adding nanoparticles such as metallic and ceramic particles into conventional lead-free solder. It is reported that the addition of such nanoparticles could strengthen the solder matrix, refine the intermetallic compounds (IMCs) formed and suppress the growth of IMCs when the joint is subjected to different thermal conditions such as thermal aging and thermal cycling. In this paper, we first review the fundamental studies on the formation and growth of IMCs in lead-free solder joints. Subsequently, we discuss the effect of the addition of nanoparticles on IMC formation and their growth under several thermal conditions. Finally, an outlook on the future growth of research in the fabrication of nanocomposite solder is provided. (review)
Oxidation and reduction kinetics of eutectic SnPb, InSn, and AuSn: a knowledge base for fluxless solder bonding applications

DEFF Research Database (Denmark)

Kuhmann, Jochen Friedrich; Preuss, A.; Adolphi, B.

1998-01-01

: (1) SnPb; (2) InSn; (3) AuSn. The studies of the oxidation kinetics show that the growth of the native oxide, which covers the solder surfaces from the start of all soldering operations is self-limiting. The rate of oxidation on the molten, metallic solder surfaces is significantly reduced...... and reduction kinetics, are applied to flip-chip (FC) bonding experiments in vacuum with and without the injection of H2. Wetting in vacuum is excellent but the self-alignment during flip-chip soldering is restricted. The desired, perfectly self-aligned FC-bonds have been only achieved, using evaporated...
Influence of nanoparticle addition on the formation and growth of intermetallic compounds (IMCs) in Cu/Sn–Ag–Cu/Cu solder joint during different thermal conditions

Science.gov (United States)

Ting Tan, Ai; Wen Tan, Ai; Yusof, Farazila

2015-01-01

Nanocomposite lead-free solders are gaining prominence as replacements for conventional lead-free solders such as Sn–Ag–Cu solder in the electronic packaging industry. They are fabricated by adding nanoparticles such as metallic and ceramic particles into conventional lead-free solder. It is reported that the addition of such nanoparticles could strengthen the solder matrix, refine the intermetallic compounds (IMCs) formed and suppress the growth of IMCs when the joint is subjected to different thermal conditions such as thermal aging and thermal cycling. In this paper, we first review the fundamental studies on the formation and growth of IMCs in lead-free solder joints. Subsequently, we discuss the effect of the addition of nanoparticles on IMC formation and their growth under several thermal conditions. Finally, an outlook on the future growth of research in the fabrication of nanocomposite solder is provided. PMID:27877786
Microstructural and mechanical properties analysis of extruded Sn–0.7Cu solder alloy

Directory of Open Access Journals (Sweden)

Abdoul-Aziz Bogno

2015-01-01

Full Text Available The properties and performance of lead-free solder alloys such as fluidity and wettability are defined by the alloy composition and solidification microstructure. Rapid solidification of metallic alloys is known to result in refined microstructures with reduced microsegregation and improved mechanical properties of the final products as compared to normal castings. The rapidly solidified Sn-based solders by melt spinning were shown to be suitable for soldering with low temperature and short soldering duration. In the present study, rapidly solidified Sn–0.7 wt.%Cu droplets generated by impulse atomization (IA were achieved as well as directional solidification under transient conditions at lower cooling rate. This paper reports on a comparative study of the rapidly solidified and the directionally solidified samples. Different but complementary characterization techniques were used to fully analyze the solidification microstructures of the samples obtained under the two cooling regimes. These include X-ray diffractometry (XRD and scanning electron microscopy (SEM. In order to compare the tensile strength and elongation to fracture of the directionally solidified ingot and strip castings with the atomized droplet, compaction and extrusion of the latter were carried out. It was shown that more balanced and superior tensile mechanical properties are available for the hot extruded samples from compacted as-atomized Sn–0.7 wt.%Cu droplets. Further, elongation-to-fracture was 2–3× higher than that obtained for the directionally solidified samples.
Development of technique for laser welding of biological tissues using laser welding device and nanocomposite solder.

Science.gov (United States)

Gerasimenko, A; Ichcitidze, L; Podgaetsky, V; Ryabkin, D; Pyankov, E; Saveliev, M; Selishchev, S

2015-08-01

The laser device for welding of biological tissues has been developed involving quality control and temperature stabilization of weld seam. Laser nanocomposite solder applied onto a wound to be weld has been used. Physicochemical properties of the nanocomposite solder have been elucidated. The nature of the tissue-organizing nanoscaffold has been analyzed at the site of biotissue welding.
Transected sciatic nerve repair by diode laser protein soldering.

Science.gov (United States)

Fekrazad, Reza; Mortezai, Omid; Pedram, MirSepehr; Kalhori, Katayoun Am; Joharchi, Khojasteh; Mansoori, Korosh; Ebrahimi, Roja; Mashhadiabbas, Fatemeh

2017-08-01

Despite advances in microsurgical techniques, repair of peripheral nerve injuries (PNI) is still a major challenge in regenerative medicine. The standard treatment for PNI includes suturing and anasthomosis of the transected nerve. The objective of this study was to compare neurorraphy (nerve repair) using standard suturingto diode laser protein soldering on the functional recovery of transected sciatic nerves. Thirty adult male Fischer-344 Wistar rats were randomly assigned to 3 groups: 1. The control group, no repair, 2. the standard of care suture group, and 3. The laser/protein solder group. For all three groups, the sciatic nerve was transected and the repair was done immediately. For the suture repair group, 10.0 prolene suture was used and for the laser/protein solder group a diode laser (500mW output power) in combination with bovine serum albumen and indocyanine green dye was used. Behavioral assessment by sciatic functional index was done on all rats biweekly. At 12weeks post-surgery, EMG recordings were done on all the rats and the rats were euthanized for histological evaluation of the sciatic nerves. The one-way ANOVA test was used for statistical analysis. The average time required to perform the surgery was significantly shorter for the laser-assisted nerve repair group compared to the suture group. The EMG evaluation revealed no difference between the two groups. Based on the sciatic function index the laser group was significantly better than the suture group after 12weeks (pneurorraphy using standard suturing methods. Copyright © 2017 Elsevier B.V. All rights reserved.
Mechanism of Solder Joint Cracks in Anisotropic Conductive Films Bonding and Solutions: Delaying Hot-Bar Lift-Up Time and Adding Silica Fillers

Directory of Open Access Journals (Sweden)

Shuye Zhang

2018-01-01

Full Text Available Micron sizes solder metallurgical joints have been applied in a thin film application of anisotropic conductive film and benefited three general advantages, such as lower joint resistance, higher power handling capability, and reliability, when compared with pressure based contact of metal conductor balls. Recently, flex-on-board interconnection has become more and more popular for mobile electronic applications. However, crack formation of the solder joint crack was occurred at low temperature curable acrylic polymer resins after bonding processes. In this study, the mechanism of SnBi58 solder joint crack at low temperature curable acrylic adhesive was investigated. In addition, SnBi58 solder joint cracks can be significantly removed by increasing the storage modulus of adhesives instead of coefficient of thermal expansion. The first approach of reducing the amount of polymer rebound can be achieved by using an ultrasonic bonding method to maintain a bonding pressure on the SnBi58 solder joints cooling to room temperature. The second approach is to increase storage modulus of adhesives by adding silica filler into acrylic polymer resins to prevent the solder joint from cracking. Finally, excellent acrylic based SnBi58 solder joints reliability were obtained after 1000 cycles thermal cycling test.
Stability of molybdenum nanoparticles in Sn-3.8Ag-0.7Cu solder during multiple reflow and their influence on interfacial intermetallic compounds

Energy Technology Data Exchange (ETDEWEB)

Haseeb, A.S.M.A., E-mail: haseeb@um.edu.my; Arafat, M.M., E-mail: arafat_mahmood@yahoo.com; Johan, Mohd Rafie, E-mail: mrafiej@um.edu.my

2012-02-15

This work investigates the effects of molybdenum nanoparticles on the growth of interfacial intermetallic compound between Sn-3.8Ag-0.7Cu solder and copper substrate during multiple reflow. Molybdenum nanoparticles were mixed with Sn-3.8Ag-0.7Cu solder paste by manual mixing. Solder samples were reflowed on a copper substrate in a 250 Degree-Sign C reflow oven up to six times. The molybdenum content of the bulk solder was determined by inductive coupled plasma-optical emission spectrometry. It is found that upon the addition of molybdenum nanoparticles to Sn-3.8Ag-0.7Cu solder, the interfacial intermetallic compound thickness and scallop diameter decreases under all reflow conditions. Molybdenum nanoparticles do not appear to dissolve or react with the solder. They tend to adsorb preferentially at the interface between solder and the intermetallic compound scallops. It is suggested that molybdenum nanoparticles impart their influence on the interfacial intermetallic compound as discrete particles. The intact, discrete nanoparticles, by absorbing preferentially at the interface, hinder the diffusion flux of the substrate and thereby suppress the intermetallic compound growth. - Highlights: Black-Right-Pointing-Pointer Mo nanoparticles do not dissolve or react with the SAC solder during reflow. Black-Right-Pointing-Pointer Addition of Mo nanoparticles results smaller IMC thickness and scallop diameter. Black-Right-Pointing-Pointer Mo nanoparticles influence the interfacial IMC through discrete particle effect.
Glass formulation requirements for Hanford coupled operations using crystalline silicotitanates (CST)

International Nuclear Information System (INIS)

Andrews, M.K.; Harbour, J.R.

1997-01-01

The U.S. Department of Energy (DOE) through the Richland Operations Office has requested proposals from the private sector for the treatment of waste from the Hanford Waste Tanks. Phase I of this privatization initiative may include a demonstration for treatment and immobilization of both low activity and high-level waste. If the demonstration includes high-level waste, then the Cs-137 waste stream most likely will be combined with the high-level waste sludge to produce a coupled feed for immobilization (most likely vitrification using a borosilicate glass). It appears that pretreatment will involve the removal of cesium (and perhaps strontium and some transuranic radionuclides) from the supernate using an ion exchange material such as crystalline silicotitanate (CST). The ion exchange sorbent (or the eluted Cs-137) can then be combined with the sludge and vitrified in a coupled operation similar to the DWPF process. Alternatively, the cesium-loaded ion exchange sorbent can be vitrified directly to produce a separate glass waste form. SRTC has been involved in an Office of Science and Technology (EM-50) funded project to determine if Cs-137 loaded CST can be successfully incorporated into glass at significant levels. 1 For a waste form which would include only Cs-137 loaded CST, concentrations up to 60 wt% of CST in glass have been achieved. 2 The glass produced from this demonstration is both processable and durable. This CST-only waste form could be used at Hanford if the cesium-loaded CST is vitrified in a separate melter. For coupled feed operations, the CST would be mixed with high-level radioactive sludge from the Hanford tanks. This report provides the basis and the path forward for SRTC's efforts at developing a glass frit formulation which will incorporate both Hanford sludge and cesium-loaded CST for a coupled flowsheet. The goal of this work is to demonstrate the feasibility of vitrification as a method for immobilization of coupled feed (specifically
Analytical electron microscopy examination of solid reaction products in long-term test of SRL 200 waste glasses

International Nuclear Information System (INIS)

Buck, E.C.; Fortner, J.A.; Bates, J.K.; Feng, X.; Dietz, N.L.; Bradley, C.R.; Tani, B.S.

1993-01-01

Alteration phases, found on the leached surfaces and present as colloids in the leachates of 200-based frit (fully active and simulated) nuclear waste glass, reacted under static test conditions, at a surface area to leachate volume ratio of 20,000 m -1 for 15 days to 728 days, have been examined by analytical electron microscopy. The compositions of the secondary phases were determined using x-ray energy dispersive spectroscopy and electron energy loss spectroscopy, and structural analysis was accomplished by electron diffraction. Long-term samples of simulated glass, which had undergone an acceleration of reaction after 182 days, possessed a number of silicate secondary phases, including; smectite (iron silicate and potassium iron alumina-silicate, weeksite (uranium silicate), zeolite (calcium potassium alumino-silicate), tobermorite (calcium silicate), and a pure silica phase. However, uranium silicates and smectite have also been observed in tests, which have not undergone the acceleration of reaction, in both the leachate and leached layer, suggesting that these phases are not responsible for the acceleration of reaction
The Impact of the Proposed delta Gp Limits on Glass Formulation Efforts: Part II. Experimental Results

International Nuclear Information System (INIS)

PEELER, DAVID

2004-01-01

The Savannah River National Laboratory (SRNL) has initiated studies to assess alternative durability options that may provide access to compositional regions of interest in support of the accelerated cleanup mission at the Defense Waste Processing Facility (DWPF). One of the options being pursued is the redefinition of the durability model acceptability limits. Some of the conservative steps used in establishing the current limits without compromising the high confidence required for meeting the specification on the waste form quality were identified and eliminated. The results led to a set of three new Property Acceptability Region (PAR) values for the preliminary glass dissolution estimator that has the potential to allow access to compositional regions of interest to improve melt rate or waste loading. Although these limits are available for implementation, there is no driving force to do so with the current sludge batch (i.e., the current Frit 418 - Sludge Batch 3 (SB3) system is TL limited). The objectives of this task were to investigate (and generate) the incentive of applying the proposed durability limits in the Product Composition Control System (PCCS) from a glass formulation perspective. Glass compositions were identified or developed to transition into and through the region of GP acceptability as defined by the current and proposed durability limits. The progression through the newly defined acceptability region was accomplished by increasing the total alkali in the glass via higher alkali frits and/or waste loading (WL). The focus of this report is on the measured durability response as it compares to model predictions to assess the applicability and/or potential conservatism of the various limits or durability approaches. The normalized boron release values (NL [B] g/L) for the study glasses ranged from approximately 1.0 g/L to 2.0 g/L. The Product Consistency Test (PCT) responses provide evidence that implementation of the proposed GP limits will
Massive spalling of Cu-Zn and Cu-Al intermetallic compounds at the interface between solders and Cu substrate during liquid state reaction

Science.gov (United States)

Kotadia, H. R.; Panneerselvam, A.; Mokhtari, O.; Green, M. A.; Mannan, S. H.

2012-04-01

The interfacial intermetallic compound (IMC) formation between Cu substrate and Sn-3.8Ag-0.7Cu-X (wt.%) solder alloys has been studied, where X consists of 0-5% Zn or 0-2% Al. The study has focused on the effect of solder volume as well as the Zn or Al concentration. With low solder volume, when the Zn and Al concentrations in the solder are also low, the initial Cu-Zn and Al-Cu IMC layers, which form at the solder/substrate interface, are not stable and spall off, displaced by a Cu6Sn5 IMC layer. As the total Zn or Al content in the system increases by increasing solder volume, stable CuZn or Al2Cu IMCs form on the substrate and are not displaced. Increasing concentration of Zn has a similar effect of stabilizing the Cu-Zn IMC layer and also of forming a stable Cu5Zn8 layer, but increasing Al concentration alone does not prevent spalling of Al2Cu. These results are explained using a combination of thermodynamic- and kinetics-based arguments.
An evaluation of the spring finger solder joints on SA1358-10 and SA2052-4 connector assemblies (MC3617,W87)

International Nuclear Information System (INIS)

Kilgo, Alice C.; Vianco, Paul Thomas; Hlava, Paul Frank; Zender, Gary L.

2006-01-01

The SA1358-10 and SA2052-4 circular JT Type plug connectors are used on a number of nuclear weapons and Joint Test Assembly (JTA) systems. Prototype units were evaluated for the following specific defects associated with the 95Sn-5Sb (Sn-Sb, wt.%) solder joint used to attach the beryllium-copper (BeCu) spring fingers to the aluminum (Al) connector shell: (1) extended cracking within the fillet; (2) remelting of the solder joint during the follow-on, soldering step that attached the EMR adapter ring to the connector shell (and/or soldering the EMR shell to the adapter ring) that used the lower melting temperature 63Sn-37Pb (Sn-Pb) alloy; and (3) spalling of the Cd (Cr) layer overplating layer from the fillet surface. Several pedigrees of connectors were evaluated, which represented older fielded units as well as those assemblies that were recently constructed at Kansas City Plant. The solder joints were evaluated that were in place on connectors made with the current soldering process as well as an alternative induction soldering process for attaching the EMR adapter ring to the shell. Very similar observations were made, which crossed the different pedigrees of parts and processes. The extent of cracking in the top side fillets varied between the different connector samples and likely the EMR adapter ring to the shell. Very similar observations were made, which crossed the different pedigrees of parts and processes. The extent of cracking in the top side fillets varied between the different connector samples and likely reflected the different extents to which the connector was mated to its counterpart assembly. In all cases, the spring finger solder joints on the SA1358-10 connectors were remelted as a result of the subsequent EMR adapter ring attachment process. Spalling of the Cd (Cr) overplating layer was also observed for these connectors, which was a consequence of the remelting activity. On the other hand, the SA2052-4 connector did not exhibit evidence of

Investigation into mechanical properties of joints of heterogeneous materials brazed with high-temperature solders

International Nuclear Information System (INIS)

Lomenko, V.I.; Merkushev, V.P.; Borodina, L.M.; Sycheva, T.S.; Tokhtina, O.A.; Frolov, N.N.

1988-01-01

Mechanical properties of copper joints with copper, 12Kh18M10T steel and KhD50 composite obtained by vacuum brazing by copper-titanium solder as compared with properties of joints brazed by PSr 72 and PMFOTsr 6-4-0.03 solders in hydrogen are studied. Dependences of joints strength on temperature of contact - reactive vacuum brazing are obtained. Possible applications of joints of dissimilar materials in electrovacuum devices subjected to the effect of dynamic loadings are established
Aging treatment characteristics of solder bump joint for high reliability optical module

International Nuclear Information System (INIS)

Kim, Kyung-Seob; Yu, Chung-Hee; Yang, Jun-Mo

2004-01-01

The joint strength and fracture surfaces of Sn-37 mass% Pb and Au stud bumps for photo diode packages after isothermal aging testing were studied experimentally. Al/Au stud bumps and Cu/Sn-37 mass% Pb solders were adopted, and aged for up to 900 h to analyze the effect of intermetallic compound (IMC). The joint strength decreased with aging time. The diffraction patterns of Cu 6 Sn 5 , scallop-shaped IMCs, and planar-shaped Cu 3 Sn were characterized using transmission electron microscopy (TEM). The formation of Kirkendall voids and the growth of IMCs at the solder were found to be a possible mechanism for joint strength reduction
Method for calcining radioactive wastes

International Nuclear Information System (INIS)

Bjorklund, W.J.; McElroy, J.L.; Mendel, J.E.

1979-01-01

A method for the preparation of radioactive wastes in a low leachability form involves calcining the radioactive waste on a fluidized bed of glass frit, removing the calcined waste to melter to form a homogeneous melt of the glass and the calcined waste, and then solidifying the melt to encapsulate the radioactive calcine in a glass matrix
Paper Study Evaluations Of The Introduction Of Small Column Ion Exchange Waste Streams To The Defense Waste Processing Facility

International Nuclear Information System (INIS)

Fox, K.; Edwards, T.; Stone, M.; Koopman, D.

2010-01-01

The objective of this paper study is to provide guidance on the impact of Monosodium Titanate (MST) and Crystalline Silicotitanate (CST) streams from the Small Column Ion Exchange (SCIX) process on the Defense Waste Processing Facility (DWPF) flowsheet and glass waste form. A series of waste processing scenarios was evaluated, including projected compositions of Sludge Batches 8 through 17 (SB8 through SB17), MST additions, CST additions to Tank 40 or to a sludge batch preparation tank (Tank 42 or Tank 51, referred to generically as Tank 51 in this report), streams from the Salt Waste Processing Facility (SWPF), and two canister production rates. A wide array of potential glass frit compositions was used to support this assessment. The sludge and frit combinations were evaluated using the predictive models in the current DWPF Product Composition Control System (PCCS). The results were evaluated based on the number of frit compositions available for a particular sludge composition scenario. A large number of candidate frit compositions (e.g., several dozen to several hundred) is typically a good indicator of a sludge composition for which there is flexibility in forming an acceptable waste glass and meeting canister production rate commitments. The MST and CST streams will significantly increase the concentrations of certain components in glass, such as Nb 2 O 5 , TiO 2 , and ZrO 2 , to levels much higher than have been previously processed at DWPF. Therefore, several important assumptions, described in detail in the report, had to be made in performing the evaluations. The results of the paper studies, which must be applied carefully given the assumptions made concerning the impact of higher Ti, Zr, and Nb concentrations on model validity, provided several observations: (1) There was difficulty in identifying a reasonable number of candidate frits (and in some cases an inability to identify any candidate frits) when a waste loading of 40% is targeted for Sludge
An Approach for Impression Creep of Lead Free Microelectronic Solders

Science.gov (United States)

Anastasio, Onofrio A.

2002-06-01

Currently, the microelectronics industry is transitioning from lead-containing to lead-free solders in response to legislation in the EU and Japan. Before an alternative alloy can be designated as a replacement for current Pb-Sn extensive testing must be accomplished. One major characteristic of the alloy that must be considered is creep. Traditionally, creep testing requires numerous samples and a long tin, which thwarts the generation of comprehensive creep databases for difficult to prepare samples such as microelectronic solder joints. However, a relatively new technique, impression creep enables us to rapidly generate creep data. This test uses a cylindrical punch with a flat end to make an impression on the surface of a specimen under constant load. The steady state velocity of the indenter is found to have the same stress and temperature dependence as the conventional unidirectional creep test using bulk specimens. This thesis examines impression creep tests of eutectic Sn-Ag. A testing program and apparatus was developed constructed based on a servo hydraulic test frame. The apparatus is capable of a load resolution of 0.01N with a stability of plus/minus 0.1N, and a displacement resolution of 0.05 microns with a stability of plus/minus 0.1 microns. Samples of eutectic Sn-Ag solder were reflowed to develop the microstructure used in microelectronic packaging. Creep tests were conducted at various stresses and temperatures and showed that coarse microstructures creep more rapidly than the microstructures in the tested regime.
Electrical characteristics for Sn-Ag-Cu solder bump with Ti/Ni/Cu under-bump metallization after temperature cycling tests

Science.gov (United States)

Shih, T. I.; Lin, Y. C.; Duh, J. G.; Hsu, Tom

2006-10-01

Lead-free solder bumps have been widely used in current flip-chip technology (FCT) due to environmental issues. Solder joints after temperature cycling tests were employed to investigate the interfacial reaction between the Ti/Ni/Cu under-bump metallization and Sn-Ag-Cu solders. The interfacial morphology and quantitative analysis of the intermetallic compounds (IMCs) were obtained by electron probe microanalysis (EPMA) and field emission electron probe microanalysis (FE-EPMA). Various types of IMCs such as (Cu1-x,Agx)6Sn5, (Cu1-y,Agy)3Sn, and (Ag1-z,Cuz)3Sn were observed. In addition to conventional I-V measurements by a special sample preparation technique, a scanning electron microscope (SEM) internal probing system was introduced to evaluate the electrical characteristics in the IMCs after various test conditions. The electrical data would be correlated to microstructural evolution due to the interfacial reaction between the solder and under-bump metallurgy (UBM). This study demonstrated the successful employment of an internal nanoprobing approach, which would help further understanding of the electrical behavior within an IMC layer in the solder/UBM assembly.
Investigation of Sn-Pb solder bumps of prototype photo detectors for the LHCb experiment

CERN Document Server

Delsante, M L; Arnau-Izquierdo, G

2004-01-01

The Large Hadron Collider (LHC) is now under construction at the European Organization for Nuclear Research (CERN). LHCb is one of the dedicated LHC experiments, allowing high energy proton-proton collisions to be exploited. This paper presents the results of the metallurgic studies carried out on Sn-Pb solder bumps of prototype vacuum photo detectors under development for LHCb, and in particular for the ring imaging Cherenkov-hybrid photo diode (RICH-HPD) project. These detectors encapsulate, in a vacuum tube, an assembly made of two silicon chips bonded together by a matrix of solder bumps. Each bump lies on a suitable system of under-bump metallic layers ensuring mechanical and electrical transition between the chip pad and the solder alloy. During manufacturing of the detector, bump-bonded (BB) assemblies are exposed to severe heat cycles up to 400 degree C inducing, in the present fabrication process, a clear degradation of electrical connectivity. Several investigations such as microstructural observati...
Interconnection of thermal parameters, microstructure and mechanical properties in directionally solidified Sn–Sb lead-free solder alloys

Energy Technology Data Exchange (ETDEWEB)

Dias, Marcelino; Costa, Thiago [Department of Manufacturing and Materials Engineering, University of Campinas — UNICAMP, 13083-860 Campinas, SP (Brazil); Rocha, Otávio [Federal Institute of Education, Science and Technology of Pará — IFPA, 66093-020 Belém, PA (Brazil); Spinelli, José E. [Department of Materials Engineering, Federal University of São Carlos — UFSCar, 13565-905 São Carlos, SP (Brazil); Cheung, Noé, E-mail: cheung@fem.unicamp.br [Department of Manufacturing and Materials Engineering, University of Campinas — UNICAMP, 13083-860 Campinas, SP (Brazil); Garcia, Amauri [Department of Manufacturing and Materials Engineering, University of Campinas — UNICAMP, 13083-860 Campinas, SP (Brazil)

2015-08-15

Considerable effort is being made to develop lead-free solders for assembling in environmental-conscious electronics, due to the inherent toxicity of Pb. The search for substitute alloys of Pb–Sn solders has increased in order to comply with different soldering purposes. The solder must not only meet the expected levels of electrical performance but may also have appropriate mechanical strength, with the absence of cracks in the solder joints. The Sn–Sb alloy system has a range of compositions that can be potentially included in the class of high temperature solders. This study aims to establish interrelations of solidification thermal parameters, microstructure and mechanical properties of Sn–Sb alloys (2 wt.%Sb and 5.5 wt.%Sb) samples, which were directionally solidified under cooling rates similar to those of reflow procedures in industrial practice. A complete high-cooling rate cellular growth is shown to be associated with the Sn–2.0 wt.%Sb alloy and a reverse dendrite-to-cell transition is observed for the Sn–5.5 wt.%Sb alloy. Strength and ductility of the Sn–2.0 wt.%Sb alloy are shown not to be affected by the cellular spacing. On the other hand, a considerable variation in these properties is associated with the cellular region of the Sn–5.5 wt.%Sb alloy casting. - Graphical abstract: Display Omitted - Highlights: • The microstructure of the Sn–2 wt.%Sb alloy is characterized by high-cooling rates cells. • Reverse dendrite > cell transition occurs for Sn–5.5 wt.%Sb alloy: cells prevail for cooling rates > 1.2 K/s. • Sn–5.5 wt.%Sb alloy: the dendritic region occurs for cooling rates < 0.9 K/s. • Sn–5.5 wt.%Sb alloy: tensile properties are improved with decreasing cellular spacing.
Measurement of erosion of stainless steel by molten lead-free solder using micro-focus x-ray CT system

International Nuclear Information System (INIS)

Nishikawa, Hiroshi; Takemoto, Tadashi; Kang, Songai

2009-01-01

The severe erosion damage, which is caused by a molten lead-free solder, of wave solder equipment made into stainless steel has been encountered in operation. Then, the higher maintenance frequency and reduced life time of wave solder machine component is a serious issue in a manufacturing process. In this study, the evaluation method of erosion of stainless steel by molten lead-free solders was investigated using micro-focus X-ray systems for fluoroscopic and computed tomography (CT). As a result, it was found that the fluoroscopic image could truly reconstruct the cross-shape of the stainless steel sample after immersion test without destruction. In the case of X-ray systems for fluoroscopic and CT used in this study, three-dimensional data can be obtained. Therefore, it was possible to easily check the whole picture of the test sample after immersion test and to decide the maximum erosion depth of test sample. (author)
The effect of slurry rheology on cold cap formation

International Nuclear Information System (INIS)

Yasuda, D.D.; Hrma, P.

1991-01-01

Yield stress, viscosity, and flow distance were measured on three simulated nuclear waste feeds at different temperatures and oxide loadings. Hydroxide, formate, and frit feeds, to produce glass of identical composition, were tested. Application of the results to a slurry fed waste glass melter is discussed
In-vitro investigations of skin closure using diode laser and protein solder containing gold nano shells

International Nuclear Information System (INIS)

Nourbakhsh, M. S.; Etrati Khosroshahi, M.

2011-01-01

Laser tissue soldering is a new technique for repair of various tissues including the skin, liver, articular cartilage and nerves and is a promising alternative to suture. To overcome the problems of thermal damage to surrounding tissues and low laser penetration depth, some exogenous chromophores such as gold nano shells, a new class of nanoparticles consisting of a dielectric core surrounded by a thin metal shell, are used. The aims of this study were to use two different concentrations of gold nano shells as the exogenous material for skin tissue soldering and also to examine the effects of laser soldering parameters on the properties of the repaired skin. Material and Methods: Two mixtures of albumin solder and different concentrations of gold nano shells were prepared. A full thickness incision of 2*20 mm 2 was made on the surface and after placing 50 μ1 of the solder mixture on the incision, an 810 nm diode laser was used to irradiate it at different power densities. The changes of tensile strength, σt, due to temperature rise, number of scan (Ns), and scan velocity (Vs) were investigated. Results: The results showed that the tensile strength of the repaired skin increased with increasing irradiance for both gold nano shell concentrations. In addition, at constant laser irradiance (I), the tensile strength of the repaired incision increased with increasing Ns and decreasing Vs. In our case, this corresponded to σt = 1610 g/cm 2 at I ∼ 60 W cm-2, T ∼ 65 d egree C , Ns = 10 and Vs = 0.2 mms-1. Discussion and Conclusion: Gold nano shells can be used as an indocyanine green dye alterative for laser tissue soldering. Although by increasing the laser power density, the tensile strength of the repaired skin increases, an optimum power density must be considered due to the resulting increase in tissue temperature.
Development of gold based solder candidates for flip chip assembly

DEFF Research Database (Denmark)

Chidambaram, Vivek; Hald, John; Hattel, Jesper Henri

2009-01-01

Flip chip technology is now rapidly replacing the traditional wire bonding interconnection technology in the first level packaging applications due to the miniaturization drive in the microelectronics industry. Flip chip assembly currently involves the use of high lead containing solders...
Interfacial Reaction and IMC Growth of an Ultrasonically Soldered Cu/SAC305/Cu Structure during Isothermal Aging

Directory of Open Access Journals (Sweden)

Yulong Li

2018-01-01

Full Text Available In order to accelerate the growth of interfacial intermetallic compound (IMC layers in a soldering structure, Cu/SAC305/Cu was first ultrasonically spot soldered and then subjected to isothermal aging. Relatively short vibration times, i.e., 400 ms and 800 ms, were used for the ultrasonic soldering. The isothermal aging was conducted at 150 °C for 0, 120, 240, and 360 h. The evolution of microstructure, the IMC layer growth mechanism during aging, and the shear strength of the joints after aging were systemically investigated. Results showed the following. (i Formation of intermetallic compounds was accelerated by ultrasonic cavitation and streaming effects, the thickness of the interfacial Cu6Sn5 layer increased with aging time, and a thin Cu3Sn layer was identified after aging for 360 h. (ii The growth of the interfacial IMC layer of the ultrasonically soldered Cu/SAC305/Cu joints followed a linear function of the square root of the aging time, revealing a diffusion-controlled mechanism. (iii The tensile shear strength of the joint decreased to a small extent with increasing aging time, owing to the combined effects of IMC grain coarsening and the increase of the interfacial IMC. (iv Finally, although the fracture surfaces and failure locations of the joint soldered with 400 ms and 800 ms vibration times show similar characteristics, they are influenced by the aging time.
Physics of Failure as a Basis for Solder Elements Reliability Assessment in Wind Turbines

DEFF Research Database (Denmark)

Kostandyan, Erik; Sørensen, John Dalsgaard

2012-01-01

description of the reliability. A physics of failure approach is applied. A SnAg solder component used in power electronics is used as an example. Crack propagation in the SnAg solder is modeled and a model to assess the accumulated plastic strain is proposed based on a physics of failure approach. Based...... on the proposed model it is described how to find the accumulated linear damage and reliability levels for a given temperature loading profile. Using structural reliability methods the reliability levels of the electrical components are assessed by introducing scale factors for stresses....
Silicon–glass-based single piezoresistive pressure sensors for harsh environment applications

International Nuclear Information System (INIS)

San, Haisheng; Zhang, Hong; Zhang, Qiang; Yu, Yuxi; Chen, Xuyuan

2013-01-01

Silicon–glass (Si–glass)-based single piezoresistive pressure sensors were designed and fabricated by standard MEMS technology. The single piezoresistive sensing element was designed to be on the lower surface of the silicon diaphragm and be vacuum-sealed in a Si–glass cavity, which form a self-packaging protection structure helpful to the applications of sensors in harsh media. The pressure sensors were fabricated using a Si–glass anodic bonding technique, and the embedded Al feedthrough lines at the Si–glass interface are used to realize the electrical connections between the piezo-sensing element and the electrode-pads, and two larger-size electrode-pads are fabricated for realizing the soldered electrical connection between the sensor and the external circuit. The performance of the pressure sensors was characterized by a pressure test system at different temperature conditions. The temperature compensation was performed by the difference between the output voltage at zero-pressure and the output at operation pressure. The measurement results show that the sensitivity is 24 mV V –1 MPa −1 , the coefficient of sensitivity is 0.14% FS °C –1 , and both the zero-point offset and the temperature coefficient of offset are equal to zero, which are able to meet the commercial application requirements. However, a nonlinearity of 5.2% FS caused by the balloon effect would considerably worsen the accuracy of the pressure sensor. It is suggested to reduce the balloon effect by using a bossed-diaphragm structure in the pressure sensor. (paper)
Process for solidifying high-level nuclear waste

Science.gov (United States)

Ross, Wayne A.

1978-01-01

The addition of a small amount of reducing agent to a mixture of a high-level radioactive waste calcine and glass frit before the mixture is melted will produce a more homogeneous glass which is leach-resistant and suitable for long-term storage of high-level radioactive waste products.
Evaluation on Dorsey Method in Surface Tension Measurement of Solder Liquids Containing Surfactants

Science.gov (United States)

Zhao, Xingke; Xie, Feiming; Fan, Jinsheng; Liu, Dayong; Huang, Jihua; Chen, Shuhai

2018-06-01

With the purpose of developing a feasible approach for measuring the surface tension of solders containing surfactants, the surface tension of Sn-3Ag-0.5Cu-xP solder alloys, with various drop sizes as well as different phosphorus (P) content, was evaluated using the Dorsey method based on the sessile drop test. The results show that the accuracy of the surface tension calculations depends on both of sessile drop size and the liquid metal composition. With a proper drop size, in the range of 4.5 mm to 5.3 mm in equivalent spherical diameters, the deviation of the surface tension calculation can be limited to 1.43 mN·m-1 and 6.30 mN·m-1 for SnAgCu and SnAgCu-P, respectively. The surface tension of SnAgCu-xP solder alloys decreases quickly to a minimum value when the P content reaches 0.5 wt% and subsequently increases slowly with the P content further increasing. The formation of a P-enriched surface layer and Sn4P3 intermetallic phases is regarded to be responsible for the decreasing and subsequent increasing of surface tension, respectively.
Effect of cooling rate during solidification of Sn-9Zn lead-free solder alloy on its microstructure, tensile strength and ductile-brittle transition temperature

Energy Technology Data Exchange (ETDEWEB)

Prabhu, K.N., E-mail: prabhukn_2002@yahoo.co.in [Department of Metallurgical and Materials Engineering, National Institute of Technology Karnataka, Surathkal, Mangalore 575 025 (India); Deshapande, Parashuram; Satyanarayan [Department of Metallurgical and Materials Engineering, National Institute of Technology Karnataka, Surathkal, Mangalore 575 025 (India)

2012-01-30

Highlights: Black-Right-Pointing-Pointer Effect of cooling rate on tensile and impact properties of Sn-9Zn alloy was assessed. Black-Right-Pointing-Pointer Both DBTT and UTS of the solder alloy increased with increase in cooling rate. Black-Right-Pointing-Pointer An optimum cooling rate during solidification would minimize DBTT and maximize UTS. - Abstract: Solidification rate is an important variable during processing of materials, including soldering, involving solidification. The rate of solidification controls the metallurgical microstructure at the solder joint and hence the mechanical properties. A high tensile strength and a lower ductile-brittle transition temperature are necessary for reliability of solder joints in electronic circuits. Hence in the present work, the effect of cooling rate during solidification on microstructure, impact and tensile properties of Sn-9Zn lead-free solder alloy was investigated. Four different cooling media (copper and stainless steel moulds, air and furnace cooling) were used for solidification to achieve different cooling rates. Solder alloy solidified in copper mould exhibited higher cooling rate as compared to other cooling media. The microstructure is refined as the cooling rate was increased from 0.03 to 25 Degree-Sign C/s. With increase in cooling rate it was observed that the size of Zn flakes became finer and distributed uniformly throughout the matrix. Ductile-to-brittle transition temperature (DBTT) of the solder alloy increased with increase in cooling rate. Fractured surfaces of impact test specimens showed cleavage like appearance and river like pattern at very low temperatures and dimple like appearance at higher temperatures. The tensile strength of the solder alloy solidified in Cu and stainless moulds were higher as compared to air and furnace cooled samples. It is therefore suggested that the cooling rate during solidification of the solder alloy should be optimum to maximize the strength and minimize the
Effect of cooling rate during solidification of Sn–9Zn lead-free solder alloy on its microstructure, tensile strength and ductile–brittle transition temperature

International Nuclear Information System (INIS)

Prabhu, K.N.; Deshapande, Parashuram; Satyanarayan

2012-01-01

Highlights: ► Effect of cooling rate on tensile and impact properties of Sn–9Zn alloy was assessed. ► Both DBTT and UTS of the solder alloy increased with increase in cooling rate. ► An optimum cooling rate during solidification would minimize DBTT and maximize UTS. - Abstract: Solidification rate is an important variable during processing of materials, including soldering, involving solidification. The rate of solidification controls the metallurgical microstructure at the solder joint and hence the mechanical properties. A high tensile strength and a lower ductile–brittle transition temperature are necessary for reliability of solder joints in electronic circuits. Hence in the present work, the effect of cooling rate during solidification on microstructure, impact and tensile properties of Sn–9Zn lead-free solder alloy was investigated. Four different cooling media (copper and stainless steel moulds, air and furnace cooling) were used for solidification to achieve different cooling rates. Solder alloy solidified in copper mould exhibited higher cooling rate as compared to other cooling media. The microstructure is refined as the cooling rate was increased from 0.03 to 25 °C/s. With increase in cooling rate it was observed that the size of Zn flakes became finer and distributed uniformly throughout the matrix. Ductile-to-brittle transition temperature (DBTT) of the solder alloy increased with increase in cooling rate. Fractured surfaces of impact test specimens showed cleavage like appearance and river like pattern at very low temperatures and dimple like appearance at higher temperatures. The tensile strength of the solder alloy solidified in Cu and stainless moulds were higher as compared to air and furnace cooled samples. It is therefore suggested that the cooling rate during solidification of the solder alloy should be optimum to maximize the strength and minimize the DBTT.
Design of Experiments to Determine Causes of Flex Cable Solder Wicking, Discoloration and Hole Location Defects

Energy Technology Data Exchange (ETDEWEB)

Wolfe, Larry

2009-04-22

Design of Experiments (DoE) were developed and performed in an effort to discover and resolve the causes of three different manufacturing issues; large panel voids after Hot Air Solder Leveling (HASL), cable hole locations out of tolerance after lamination and delamination/solder wicking around flat flex cable circuit lands after HASL. Results from a first DoE indicated large panel voids could be eliminated by removing the pre-HASL cleaning. It also revealed eliminating the pre-HASL bake would not be detrimental when using a hard press pad lamination stackup. A second DoE indicated a reduction in hard press pad stackup lamination pressure reduced panel stretch in the y axis approximately 70%. A third DoE illustrated increasing the pre-HASL bake temperature could reduce delamination/solder wicking when using a soft press pad lamination stackup.

Evaluating print performance of Sn-Ag-Cu lead-free solder pastes used in electronics assembly process

Science.gov (United States)

Mallik, S.; Bauer, R.; Hübner, F.; Ekere, N. N.

2011-01-01

Solder paste is the most widely used interconnection material in the electronic assembly process for attaching electronic components/devices directly onto the surface of printed circuit boards, using stencil printing process. This paper evaluates the performance of three different commercially available Sn-Ag-Cu solder pastes formulated with different particle size distributions (PSD), metal content and alloy composition. A series of stencil printing tests were carried out using a specially designed stencil of 75 μm thickness and apertures of 300×300 μm2 dimension and 500 μm pitch sizes. Solder paste printing behaviors were found related to attributes such as slumping and surface tension and printing performance was correlated with metal content and PSD. The results of the study should benefit paste manufacturers and SMT assemblers to improve their products and practices.
Interfacial Microstructure and Shear Strength of Brazed Cu-Cr-Zr Alloy Cylinder and Cylindrical Hole by Au Based Solder

Directory of Open Access Journals (Sweden)

Zaihua Li

2017-07-01

Full Text Available Au-Ge-Ni solder was chosen for brazing of the Cu-Cr-Zr alloy cylinder and a part with a cylindrical hole (sleeve below 550 °C. The Au based solder was first sintered on the surface of the cylinder and then brazed to the inner surface of the sleeve. The effects of the heating process, the temperature and the holding time at the temperature on the microstructure of the sintered layer on the surface of the cylinder, the brazed interfacial microstructure, and the brazed shear strength between the cylinder and the sleeve were investigated by scanning electron microscope, energy dispersive X-ray spectroscopy analysis, and tensile shear tests. By approach of side solder melt feeding and brazing under proper parameters, the voids and micro cracks due to a lack of enough solder melt feeding are greatly lessened and the brazed shear strength of 100 MPa is ensured even with large clearances around 0.01 mm.
Three-dimensional (3D) visualization of reflow porosity and modeling of deformation in Pb-free solder joints

International Nuclear Information System (INIS)

Dudek, M.A.; Hunter, L.; Kranz, S.; Williams, J.J.; Lau, S.H.; Chawla, N.

2010-01-01

The volume, size, and dispersion of porosity in solder joints are known to affect mechanical performance and reliability. Most of the techniques used to characterize the three-dimensional (3D) nature of these defects are destructive. With the enhancements in high resolution computed tomography (CT), the detection limits of intrinsic microstructures have been significantly improved. Furthermore, the 3D microstructure of the material can be used in finite element models to understand their effect on microscopic deformation. In this paper we describe a technique utilizing high resolution (< 1 μm) X-ray tomography for the three-dimensional (3D) visualization of pores in Sn-3.9Ag-0.7Cu/Cu joints. The characteristics of reflow porosity, including volume fraction and distribution, were investigated for two reflow profiles. The size and distribution of porosity size were visualized in 3D for four different solder joints. In addition, the 3D virtual microstructure was incorporated into a finite element model to quantify the effect of voids on the lap shear behavior of a solder joint. The presence, size, and location of voids significantly increased the severity of strain localization at the solder/copper interface.
Immobilization of krypton-85 in zeolite 5A and porous glass

International Nuclear Information System (INIS)

Christensen, A.B.; DelDebbio, J.A.; Knecht, D.A.; Tanner, J.E.; Cossel, S.C.

1981-12-01

This report demonstrates the technical and economic feasibility for immobilizing krypton-85 by high pressure/high temperature encapsulation in zeolite 5A or thirsty Vyco porous glass. Data are presented to show how process conditions affect the encapsulation and how to compact the zeolite beads with glass frit or other additives to form a fused mass with low dispersibility potential. Krypton specific loadings of 30 and 50 m 3 STP gas per m 3 solid are readily achieved at 100 MPa in porous glass at 900 0 C and zeolite 5A at 700 0 C. Krypton is encapsulated by a sintering process where the porous glass and zeolite 5A voids are sealed. With zeolite 5A, the initial water concentration has a catalytic effect on the sintering, resulting in a transition from crystalline zeolite 5A to an amorphous aluminosilicate. Krypton leakage experiments are used to predict leakage rates from glass or zeolite of less than 0.03% and 0.3% for 10-y storage at 300 and 400 0 C, respectively. Heating the loaded zeolite at 600 to 700 0 C for 4 h removes 0.1% of the total krypton which is loosely held and reduces the subsequent leakage rates at 300 to 400 0 C. Zeolite 5A is chosen as the preferred material to immobilize krypton-85. A preconceptual design and cost estimate is given for a facility to encapsulate 110% of the krypton production of a 2000 metric ton of heavy metal per year reprocessing plant, or 230 m 3 of gas containing 19 MCi of krypton-85. A hot isostatic press (HIP) with an isolated work zone of 8 or 16 L capacity is required to operate for 600 or 300 cycles per year, respectively. Existing HIP technology uses work zones from 1 to 3500 L capacity at similar production rates. A preliminary safety evaluation shows that an incredible worst case accident could be contained and the maximum off-site dose would be well below accident protective action guidance levels
Impurity Effects in Electroplated-Copper Solder Joints

Directory of Open Access Journals (Sweden)

Hsuan Lee

2018-05-01

Full Text Available Copper (Cu electroplating is a mature technology, and has been extensively applied in microelectronic industry. With the development of advanced microelectronic packaging, Cu electroplating encounters new challenges for atomic deposition on a non-planar substrate and to deliver good throwing power and uniform deposit properties in a high-aspect-ratio trench. The use of organic additives plays an important role in modulating the atomic deposition to achieve successful metallic coverage and filling, which strongly relies on the adsorptive and chemical interactions among additives on the surface of growing film. However, the adsorptive characteristic of organic additives inevitably results in an incorporation of additive-derived impurities in the electroplated Cu film. The incorporation of high-level impurities originating from the use of polyethylene glycol (PEG and chlorine ions significantly affects the microstructural evolution of the electroplated Cu film, and the electroplated-Cu solder joints, leading to the formation of undesired voids at the joint interface. However, the addition of bis(3-sulfopropyl disulfide (SPS with a critical concentration suppresses the impurity incorporation and the void formation. In this article, relevant studies were reviewed, and the focus was placed on the effects of additive formula and plating parameters on the impurity incorporation in the electroplated Cu film, and the void formation in the solder joints.
Mechanistic Prediction of the Effect of Microstructural Coarsening on Creep Response of SnAgCu Solder Joints

Science.gov (United States)

Mukherjee, S.; Chauhan, P.; Osterman, M.; Dasgupta, A.; Pecht, M.

2016-07-01

Mechanistic microstructural models have been developed to capture the effect of isothermal aging on time dependent viscoplastic response of Sn3.0Ag0.5Cu (SAC305) solders. SnAgCu (SAC) solders undergo continuous microstructural coarsening during both storage and service because of their high homologous temperature. The microstructures of these low melting point alloys continuously evolve during service. This results in evolution of creep properties of the joint over time, thereby influencing the long term reliability of microelectronic packages. It is well documented that isothermal aging degrades the creep resistance of SAC solder. SAC305 alloy is aged for (24-1000) h at (25-100)°C (~0.6-0.8 × T melt). Cross-sectioning and image processing techniques were used to periodically quantify the effect of isothermal aging on phase coarsening and evolution. The parameters monitored during isothermal aging include size, area fraction, and inter-particle spacing of nanoscale Ag3Sn intermetallic compounds (IMCs) and the volume fraction of micronscale Cu6Sn5 IMCs, as well as the area fraction of pure tin dendrites. Effects of microstructural evolution on secondary creep constitutive response of SAC305 solder joints were then modeled using a mechanistic multiscale creep model. The mechanistic phenomena modeled include: (1) dispersion strengthening by coarsened nanoscale Ag3Sn IMCs in the eutectic phase; and (2) load sharing between pro-eutectic Sn dendrites and the surrounding coarsened eutectic Sn-Ag phase and microscale Cu6Sn5 IMCs. The coarse-grained polycrystalline Sn microstructure in SAC305 solder was not captured in the above model because isothermal aging does not cause any significant change in the initial grain size and orientation of SAC305 solder joints. The above mechanistic model can successfully capture the drop in creep resistance due to the influence of isothermal aging on SAC305 single crystals. Contribution of grain boundary sliding to the creep strain of
The impact of the MCU life extension solvent on sludge batch 8 projected operating windows

International Nuclear Information System (INIS)

Peeler, D.K.; Edwards, T.B.

2013-01-01

As a part of the Actinide Removal Process (ARP)/Modular Caustic Side Solvent Extraction Unit (MCU) Life Extension Project, a next generation solvent (NGS) and a new strip acid will be deployed. The strip acid will be changed from dilute nitric acid to dilute boric acid (0.01 M). Because of these changes, experimental testing or evaluations with the next generation solvent are required to determine the impact of these changes (if any) to Chemical Process Cell (CPC) activities, glass formulation strategies, and melter operations at the Defense Waste Processing Facility (DWPF). The introduction of the dilute (0.01 M) boric acid stream into the DWPF flowsheet has a potential impact on glass formulation and frit development efforts since B203 is a major oxide in frits developed for DWPF. Prior knowledge of this stream can be accounted for during frit development efforts but that was not the case for Sludge Batch 8 (SB8). Frit 803 has already been recommended and procured for SB8 processing; altering the frit to account for the incoming boron from the strip effluent (SE) is not an option for SB8. Therefore, the operational robustness of Frit 803 to the introduction of SE including its compositional tolerances (i.e., up to 0.0125M boric acid) is of interest and was the focus of this study. The primary question to be addressed in the current study was: What is the impact (if any) on the projected operating windows for the Frit 803 - SB8 flowsheet to additions of B203 from the SE in the Sludge Receipt and Adjustment Tank (SRAT)? More specifically, will Frit 803 be robust to the potential compositional changes occurring in the SRAT due to sludge variation, varying additions of ARP and/or the introduction of SE by providing access to waste loadings (WLs) of interest to DWPF? The Measurement Acceptability Region (MAR) results indicate there is very little, if any, impact on the projected operating windows for the Frit 803 - SB8 system regardless of the presence or absence of
Vitrification of liquid waste from nuclear power plants

International Nuclear Information System (INIS)

Sheng Jiawei; Choi, Kwansik; Song, Myung-Jae

2001-01-01

Glass is an acceptable waste form to solidify the low-level waste from nuclear power plants (NPPs) because of the simplicity of processing and its unique ability to accept a wide variety of waste streams. Vitrification is being considered to solidify the high-boron-containing liquid waste generated from Korean NPPs. This study dealt with the development of a glass formulation to solidify the liquid waste. Studies were conducted in a borosilicate glass system. Crucible studies have been performed with surrogate waste. Several developed glass frits were evaluated to determine their suitability for vitrifying the liquid waste. The results indicated that the 20 wt% waste oxides loading required could not be obtained using these glass frits. Flyash produced from coal-burning electric power stations, whose major components are SiO 2 and Al 2 O 3 , is a desirable glass network former. Detailed product evaluations including waste loading, homogeneity, chemical durability and viscosity, etc., were carried out on selected formulations using flyash. Up to 30 wt% of the waste oxides was successfully solidified into the flyash after the addition of 5-10 wt% Na 2 O at 1200 deg. C
Solder bond requirement for large, built-up, high-performance conductors

International Nuclear Information System (INIS)

Willig, R.L.

1981-01-01

Some large built-up conductors fabricated for large superconducting magnets are designed to operate above the maximum recovery current. Because the stability of these conductors is sensitive to the quality of the solder bond joining the composite superconductor to the high-conductivity substrate, a minimum bond requirement is necessary. The present analysis finds that the superconductor is unstable and becomes abruptly resistive when there are temperature excursions into the current sharing region of a poorly bonded conductor. This abrupt transition, produces eddy current heating in the vicinity of the superconducting filaments and causes a sharp reduction in the minimum propagating zone (MPZ) energy. This sensitivity of the MPZ energy to the solder bond contact area is used to specify a minimum bond requirement. For the superconducting MHD magnet built for the Component Development Integration Facility (CDIF), the minimum bonded surface area is .68 cm/sup 2//cm which is 44% of the composite perimeter. 5 refs
In situ investigation of SnAgCu solder alloy microstructure

International Nuclear Information System (INIS)

Pietrikova, Alena; Bednarcik, Jozef; Durisin, Juraj

2011-01-01

Research highlights: → In situ X-ray diffraction investigation enabled detailed analysis of the melting and solidification process of the SAC305 alloy. → It was found that the SAC305 solder melts at 230 deg. C. When cooling from 240 deg. C the SAC305 alloy solidifies at the temperature of 214 deg. C. During solidification β-Sn and Cu 6 Sn 5 is also formed. Formation of Ag 3 Sn occurs at 206 deg. C and the remaining amount of alloy crystallizes approximately at 160 deg. C. → Furthermore, observation of the thermal expansion behaviour of the β-Sn tetragonal unit cell revealed linear dependence of the unit cell volume on temperature. The unit cell parameters a and c also increase linearly with the temperature. Despite the fact that the c parameter is substantially smaller than parameter a, it exhibits a significantly higher linear thermal expansion coefficient. Comparison between data obtained during heating and cooling indicates that the thermal expansion coefficient is slightly greater in the case of cooling. - Abstract: In situ X-ray diffraction experiments, using synchrotron radiation, were employed to analyze microstructure evolution of the 96.5Sn3Ag0.5Cu (wt.%)-SAC305 lead-free solder alloy during heating (30-240 deg. C), isothermal dwell (240 deg. C) and cooling (240-30 deg. C). The special emphasis was placed on the study of the melting and solidification processes, explaining formation, distribution and the order of crystallization of the crystal phases (β-Sn, intermetallic compounds) in the solder alloy. Furthermore, thermal expansion behaviour of the main constituent phase β-Sn was analyzed prior to melting and after the consequent solidification.
Radioactive waste vitrification: A review

International Nuclear Information System (INIS)

Cole, L.L.; Fields, D.E.

1989-08-01

The research and development of an immobilization process for the containment of nuclear high-level liquid waste has been underway for well-over the past four decades. The method that has become the state-of-the-art is the liquid-fed ceramic melter process which converts a mixture of high-level liquid waste and glass forming frit to a borosilicate glass product. This report gives a chronological review of the various vitrification processes starting with the very first reported process in 1960. Information on the early methods of frit selection as well as information on the currently computerized method are presented. The importance of all these parameters is discussed with regard to product durability. 26 refs., 8 figs., 1 tab
Diode Lasers used in Plastic Welding and Selective Laser Soldering - Applications and Products

Science.gov (United States)

Reinl, S.

Aside from conventional welding methods, laser welding of plastics has established itself as a proven bonding method. The component-conserving and clean process offers numerous advantages and enables welding of sensitive assemblies in automotive, electronic, medical, human care, food packaging and consumer electronics markets. Diode lasers are established since years within plastic welding applications. Also, soft soldering using laser radiation is becoming more and more significant in the field of direct diode laser applications. Fast power controllability combined with a contactless temperature measurement to minimize thermal damage make the diode laser an ideal tool for this application. These advantages come in to full effect when soldering of increasingly small parts in temperature sensitive environments is necessary.
Numerical prediction of mechanical properties of Pb-Sn solder alloys containing antimony, bismuth and or silver ternary trace elements

Science.gov (United States)

Gadag, Shiva P.; Patra, Susant

2000-12-01

Solder joint interconnects are mechanical means of structural support for bridging the various electronic components and providing electrical contacts and a thermal path for heat dissipation. The functionality of the electronic device often relies on the structural integrity of the solder. The dimensional stability of solder joints is numerically predicted based on their mechanical properties. Algorithms to model the kinetics of dissolution and subsequent growth of intermetallic from the complete knowledge of a single history of time-temperature-reflow profile, by considering equivalent isothermal time intervals, have been developed. The information for dissolution is derived during the heating cycle of reflow and for the growth process from cooling curve of reflow profile. A simple and quick analysis tool to derive tensile stress-strain maps as a function of the reflow temperature of solder and strain rate has been developed by numerical program. The tensile properties are used in modeling thermal strain, thermal fatigue and to predict the overall fatigue life of solder joints. The numerical analysis of the tensile properties as affected by their composition and rate of testing, has been compiled in this paper. A numerical model using constitutive equation has been developed to evaluate the interfacial fatigue crack growth rate. The model can assess the effect of cooling rate, which depends on the level of strain energy release rate. Increasing cooling rate from normalizing to water-quenching, enhanced the fatigue resistance to interfacial crack growth by up to 50% at low strain energy release rate. The increased cooling rates enhanced the fatigue crack growth resistance by surface roughening at the interface of solder joint. This paper highlights salient features of process modeling. Interfacial intermetallic microstructure is affected by cooling rate and thereby affects the mechanical properties.
Rapid Solidification of Sn-Cu-Al Alloys for High-Reliability, Lead-Free Solder: Part II. Intermetallic Coarsening Behavior of Rapidly Solidified Solders After Multiple Reflows

Science.gov (United States)

Reeve, Kathlene N.; Choquette, Stephanie M.; Anderson, Iver E.; Handwerker, Carol A.

2016-12-01

Controlling the size, dispersion, and stability of intermetallic compounds in lead-free solder alloys is vital to creating reliable solder joints regardless of how many times the solder joints are melted and resolidified (reflowed) during circuit board assembly. In this article, the coarsening behavior of Cu x Al y and Cu6Sn5 in two Sn-Cu-Al alloys, a Sn-2.59Cu-0.43Al at. pct alloy produced via drip atomization and a Sn-5.39Cu-1.69Al at. pct alloy produced via melt spinning at a 5-m/s wheel speed, was characterized after multiple (1-5) reflow cycles via differential scanning calorimetry between the temperatures of 293 K and 523 K (20 °C and 250 °C). Little-to-no coarsening of the Cu x Al y particles was observed for either composition; however, clustering of Cu x Al y particles was observed. For Cu6Sn5 particle growth, a bimodal size distribution was observed for the drip atomized alloy, with large, faceted growth of Cu6Sn5 observed, while in the melt spun alloy, Cu6Sn5 particles displayed no significant increase in the average particle size, with irregularly shaped, nonfaceted Cu6Sn5 particles observed after reflow, which is consistent with shapes observed in the as-solidified alloys. The link between original alloy composition, reflow undercooling, and subsequent intermetallic coarsening behavior was discussed by using calculated solidification paths. The reflowed microstructures suggested that the heteroepitaxial relationship previously observed between the Cu x Al y and the Cu6Sn5 was maintained for both alloys.
Reinforcement of high-risk anastomoses using laser-activated protein solders: a clinical study

Science.gov (United States)

Libutti, Steven K.; Bessler, Marc; Chabot, J.; Bass, Lawrence S.; Oz, Mehmet C.; Auteri, Joseph S.; Kirsch, Andrew J.; Nowygrod, Roman; Treat, Michael R.

1993-07-01

Anastomotic leakage or breakdown can result in catastrophic complications and significantly increased post-operative morbidity and mortality. Certain anastomoses are subject to a higher incidence of disruption and are therefore termed high risk. In an attempt to decrease the risk of anastomotic leaks, we reinforced sutured anastomoses with a laser activated protein solder in patients undergoing esophagojejunostomies (n equals 2), lung transplantation (n equals 2), and pancreaticojejunostomies (Whipple procedure, n equals 5). The protein solder was composed of 1.0 ml of a 25% human albumin solution, 1.0 ml of sodium hyaluronate, and 0.1 ml of Cardiogreen dye. This composition was applied to the sutured anastomosis and activated with an 860 nm pulsed diode laser. Drains were placed when appropriate and patients were followed for up to 10 months post-operatively and assessed for clinical signs of anastomotic leaks. Results to data demonstrated that there were no immediate complications as a result of the procedure. Operative time was not significantly lengthened. There were no cases of clinically significant leakage from any of the reinforced anastomoses. Laser activated protein solders may help to reduce the incidence of leakage in high risk anastomoses. Large numbers of patients and longer follow-up is needed however, to draw significant conclusions.
Performance of carbon-based hot frit substrates: I, Low pressure helium and hydrogen testing

International Nuclear Information System (INIS)

Barletta, R.; Adams, J.; Svandrlik, J.; Powell, J.R.

1993-07-01

The performance of various carbon-based materials in flowing, high-temperature helium and hydrogen is described. These materials which are candidate hot frit substrates for possible application in a PBR include various grades of graphite, carbon-carbon and vitreous carbon. Vitreous carbon showed extremely good performance in helium, while that of the various graphite grades was quite variable and, in some cases, poor. Purified grades performed better than unpurified grades, but in all cases large sample-to-sample variations in weight loss were observed. For carbon-carbon samples, the performance was intermediate. Since the weight loss in these samples was in large measure due to the loss of the densification media, improvements in the performance of carbon-carbon may be possible. With respect to the performance in hydrogen, high weight losses were observed, re-enforcing the need for coating carbon-based materials for service in a flowing hydrogen environment
Kinetics of intermetallic phase formation at the interface of Sn-Ag-Cu-X (X = Bi, In) solders with Cu substrate

International Nuclear Information System (INIS)

Hodulova, Erika; Palcut, Marian; Lechovic, Emil; Simekova, Beata; Ulrich, Koloman

2011-01-01

Highlights: → In substitutes Sn in intermetallic compounds formed at the Cu-solder interface. → Bi and In decrease the parabolic rate constant of Cu 3 Sn layer growth. → In increases the parabolic rate constant of Cu 6 Sn 5 layer growth. → High In concentrations should be avoided since they may lead to a pre-mature solder joint degradation. - Abstract: The effects of Bi and In additions on intermetallic phase formation in lead-free solder joints of Sn-3.7Ag-0.7Cu; Sn-1.0Ag-0.5Cu-1.0Bi and Sn-1.5Ag-0.7Cu-9.5In (composition given in weight %) with copper substrate are studied. Soldering of copper plate was conducted at 250 deg. C for 5 s. The joints were subsequently aged at temperatures of 130-170 deg. C for 2-16 days in a convection oven. The aged interfaces were analyzed by optical microscopy and energy dispersive X-ray spectroscopy (EDX) microanalysis. Two intermetallic layers are observed at the interface - Cu 3 Sn and Cu 6 Sn 5 . Cu 6 Sn 5 is formed during soldering. Cu 3 Sn is formed during solid state ageing. Bi and In decrease the growth rate of Cu 3 Sn since they appear to inhibit tin diffusion through the grain boundaries. Furthermore, indium was found to produce a new phase - Cu 6 (Sn,In) 5 instead of Cu 6 Sn 5 , with a higher rate constant. The mechanism of the Cu 6 (Sn,In) 5 layer growth is discussed and the conclusions for the optimal solder chemical composition are presented.
Recovery of Tin and Nitric Acid from Spent Solder Stripping Solutions

International Nuclear Information System (INIS)

Ahn, Jae-Woo; Ryu, Seong-Hyung; Kim, Tae-young

2015-01-01

Spent solder-stripping solutions containing tin, copper, iron, and lead in nitric acid solution, are by-products of the manufacture of printed-circuit boards. The recovery of these metals and the nitric acid, for re-use has economic and environmental benefits. In the spent solder-stripping solution, a systematic method to determine a suitable process for recovery of valuable metals and nitric acid was developed. Initially, more than 90% of the tin was successfully recovered as high-purity SnO 2 by thermal precipitation at 80 ℃ for 3 hours. About 94% of the nitric acid was regenerated effectively from the spent solutions by diffusion dialysis, after which there remained copper, iron, and lead in solution. Leakage of tin through the anion-exchange membrane was the lowest (0.026%), whereas Pb-leakage was highest (4.26%). The concentration of the regenerated nitric acid was about 5.1 N.
Electromigration-induced cracks in Cu/Sn3.5Ag/Cu solder reaction couple at room temperature

International Nuclear Information System (INIS)

He Hongwen; Xu Guangchen; Guo Fu

2009-01-01

Electromigration (EM) behavior of Cu/Sn 3.5 Ag/Cu solder reaction couple was investigated with a high current density of 5 x 10 3 A/cm 2 at room temperature. One dimensional structure, copper wire/solder ball/copper wire SRC was designed and fabricated to dissipate the Joule heating induced by the current flow. In addition, thermomigration effect was excluded due to the symmetrical structure of the SRC. The experimental results indicated that micro-cracks initially appeared near the cathode interface between solder matrix and copper substrate after 474 h current stressing. With current stressing time increased, the cracks propagated and extended along the cathode interface. It should be noted that the continuous Cu 6 Sn 5 intermetallic compounds (IMCs) layer both at the anode and at the cathode remained their sizes. Interestingly, tiny cracks appeared at the root of some long column-type Cu 6 Sn 5 at the cathode interface due to the thermal stress.
Liver repair and hemorrhage control by using laser soldering of liquid albumin in a porcine model.

Science.gov (United States)

Wadia, Y; Xie, H; Kajitani, M

2000-01-01

We evaluated laser soldering by using liquid albumin for welding liver injuries. Major liver trauma has a high mortality because of immediate exsanguination and a delayed morbidity from septicemia, peritonitis, biliary fistulae, and delayed secondary hemorrhage. Eight laceration (6 x 2 cm) and eight nonanatomic resection injuries (raw surface, 6 x 2 cm) were repaired. An 805-nm laser was used to weld 50% liquid albumin-indocyanine green solder to the liver surface, reinforcing it with a free autologous omental scaffold. The animals were heparinized and hepatic inflow occlusion was used for vascular control. All 16 soldering repairs were evaluated at 3 hours. All 16 laser mediated liver repairs had minimal blood loss as compared with the suture controls. No dehiscence, hemorrhage, or bile leakage was seen in any of the laser repairs after 3 hours. Laser fusion repair of the liver is a reliable technique to gain hemostasis on the raw surface as well as weld lacerations. Copyright 2000 Wiley-Liss, Inc.

Safety and Health Topics: Lead

Science.gov (United States)

... ammunition, pipes, cable covering, building material, solder, radiation shielding, collapsible tubes, and fishing weights. Lead is also ... lead linings in tanks and radiation protection, leaded glass, work involving soldering, and other work involving lead ...
A review of typical thermal fatigue failure models for solder joints of electronic components

Science.gov (United States)

Li, Xiaoyan; Sun, Ruifeng; Wang, Yongdong

2017-09-01

For electronic components, cyclic plastic strain makes it easier to accumulate fatigue damage than elastic strain. When the solder joints undertake thermal expansion or cold contraction, different thermal strain of the electronic component and its corresponding substrate is caused by the different coefficient of thermal expansion of the electronic component and its corresponding substrate, leading to the phenomenon of stress concentration. So repeatedly, cracks began to sprout and gradually extend [1]. In this paper, the typical thermal fatigue failure models of solder joints of electronic components are classified and the methods of obtaining the parameters in the model are summarized based on domestic and foreign literature research.
The variation of grain structure and the enhancement of shear strength in SAC305-0.1Ni/OSP Cu solder joint

Energy Technology Data Exchange (ETDEWEB)

Fleshman, Collin; Chen, Wei-Yu; Chou, Tzu-Ting [Department of Materials Science and Engineering, National Tsing Hua University, Hsinchu, Taiwan (China); Huang, Jia-Hong [Department of Engineering and System Science, National Tsing Hua University, Hsinchu, Taiwan (China); Duh, Jenq-Gong, E-mail: jgd@mx.nthu.edu.tw [Department of Materials Science and Engineering, National Tsing Hua University, Hsinchu, Taiwan (China)

2017-03-01

In this study, the slow speed shear test in both Sn-3.0Ag-0.5Cu (wt%)/OSP Cu and Sn-3.0Ag-0.5Cu-0.1Ni (wt%)/OSP Cu assembly with the ball heights of 300 μm and the corresponding grain structures were investigated. With the aid of Electron Back Scattering Diffraction (EBSD) analysis, single grain structure was observed in Sn-3.0Ag-0.5Cu/OSP Cu. Besides, Ni was found to control the grain structure in Sn-3.0Ag-0.5Cu-0.1Ni solder balls, showing multiple grains with partially interlaced structure. The grain variation resulted from larger undercooling caused by smaller ball size and Ni-dopant induced tiny intermetallic compounds (IMCs). IMCs serve as heterogeneous nucleation sites for β-tin and thus alter the grain structure of solder balls. The results of shear test reveal that the peak force of solder joints was efficiently enhanced by the addition of Ni. The enhancement of mechanical strength was attributed to the modification of grain structure by the introduction of Ni dopant. It is believed that the smaller grains, tiny intermetallic compounds, and the oriented interlaced area in Ni-doped solder joints became energy barriers for propagation of cracks and dislocations. It is demonstrated that Ni-doped solder joints tend to exhibit better mechanical reliability in advanced electronic packaging. - Highlights: • The grain structure and slow speed shear test performance were investigated. • Doping Ni into solder induce interlaced grain structure. • Interlaced structure can enhance mechanical reliability in BGA packaging.
SUMMARY OF 2010 DOE EM INTERNATIONAL PROGRAM STUDIES OF WASTE GLASS STRUCTURE AND PROPERTIES

Energy Technology Data Exchange (ETDEWEB)

Fox, K.; Choi, A.; Marra, J.; Billings, A.

2011-02-07

Collaborative work between the Savannah River National Laboratory (SRNL) and SIA Radon in Russia was divided among three tasks for calendar year 2010. The first task focused on the study of simplified high level waste glass compositions with the objective of identifying the compositional drivers that lead to crystallization and poor chemical durability. The second task focused on detailed characterization of more complex waste glass compositions with unexpectedly poor chemical durabilities. The third task focused on determining the structure of select high level waste glasses made with varying frit compositions in order to improve models under development for predicting the melt rate of the Defense Waste Processing Facility (DWPF) glasses. The majority of these tasks were carried out at SIA Radon. Selection and fabrication of the glass compositions, along with chemical composition measurements and evaluations of durability were carried out at SRNL and are described in this report. SIA Radon provided three summary reports based on the outcome of the three tasks. These reports are included as appendices to this document. Briefly, the result of characterization of the Task 1 glasses may indicate that glass compositions where iron is predominantly tetrahedrally coordinated have more of a tendency to crystallize nepheline or nepheline-like phases. For the Task 2 glasses, the results suggested that the relatively low fraction of tetrahedrally coordinated boron and the relatively low concentrations of Al{sub 2}O{sub 3} available to form [BO{sub 4/2}]{sup -}Me{sup +} and [AlO{sub 4/2}]{sup -}Me{sup +} tetrahedral units are not sufficient to consume all of the alkali ions, and thus these alkali ions are easily leached from the glasses. All of the twelve Task 3 glass compositions were determined to be mainly amorphous, with some minor spinel phases. Several key structural units such as metasilicate chains and rings were identified, which confirms the current modeling
Contact of ZnSb thermoelectric material to metallic electrodes using S-Bond 400 solder alloy

DEFF Research Database (Denmark)

Malik, Safdar Abbas; Le, Thanh Hung; Van Nong, Ngo

2018-01-01

and metallic electrodes. In this paper, we investigate the joining of ZnSb to Ni and Ag electrodes using a commercial solder alloy S-Bond 400 and hot-pressing technique. Ti and Cr layers are also introduced as a diffusion barrier and microstructure at the interfaces is observed by scanning electron microscopy....... We found that S-bond 400 solder reacts with Ag and Ni electrodes to form different alloys at the interfaces. Cr layer was found to be broken after joining, resulting in a thicker reaction/diffusion layer at the interface, while Ti layer was preserved....
Influence of intermetallic growth on the mechanical properties of Zn–Sn–Cu–Bi/Cu solder joints

Energy Technology Data Exchange (ETDEWEB)

Xing, Fei; Yao, Jia; Liang, Jingwei; Qiu, Xiaoming, E-mail: qiuxm13@163.com

2015-11-15

The formation of intermetallic reaction layers and their influence on shear strength and fractography was investigated between the Zn–Sn–Cu–Bi (ZSCB) and Cu substrate during the liquid state reaction at 450 °C after 10–90 s. Results showed that reliable solder joints could be obtained at 450 °C after 15–30 s of wetting, accompanied by the creation of scallop ε-CuZn{sub 5}, flat γ-Cu{sub 5}Zn{sub 8} and β-CuZn intermetallic layers in ZSCB/Cu interface. However, with excess increase of soldering time, a transient intermetallic ε-CuZn{sub 4} phase was nuclear and grew at ε-CuZn{sub 5}/γ-Cu{sub 5}Zn{sub 8} interface, which apparently deteriorated the shear strength of solder joints from 76.5 MPa to 51.6 MPa. The sensitivity of the fracture proportion was gradually transformed from monotonic ε-CuZn{sub 5} to the mixture of ε-CuZn{sub 4} and ε-CuZn{sub 5} intermetallic cleavage. Furthermore, the growth mechanism of ε-CuZn{sub 4} intermetallic phase at the ZSCB/Cu interface was discussed. - Highlights: • There are four interfacial intermetallic layers formed at the Zn–Sn–Cu–Bi/Cu interface. • The growth mechanism of ε-CuZn{sub 4} intermetallic phase was discussed. • The wetting time of Zn–Sn–Cu–Bi solder in contact with Cu substrate is a key parameter.
Interactions of Cu-substrates with titanium-alloyed Sn-Zn solders

Directory of Open Access Journals (Sweden)

Soares D.

2006-01-01

Full Text Available The interactions of copper substrate with titanium-alloyed Sn-Zn eutectic solders have been studied. Two series of experiments have been performed. The first one consisted in differential thermal analyses of Sn-Zn nearly eutectic alloys containing from 1.3 to 2.2 wt. % Ti. Diffusion couples consisted of Cu-wires and Sn-Zn-Ti liquid solders, produced at 250 and 275 OC have been prepared in the second series,. The contact times were up to 3600 s. The contact zones have been characterized by optical and scanning electron microscope. Two layers have been found along the interfaces solid/liquid. The first and the second layers are identical, respectively, with γ and ε phases of the Cu-Zn system. No changes of the chemical compositions were detected for the tested temperatures and reaction times. Continuous parabolic growth of the total diffusion zone thickness with the time of diffusion is observed. The growth is due mainly to one the formed layers (γ while the thickness of the ε-phase layer, stays almost constant for all tested diffusion times and temperatures.
Circuit reliability boosted by soldering pins of disconnect plugs to sockets

Science.gov (United States)

Pierce, W. B.

1964-01-01

Where disconnect pins must be used for wiring and testing a circuit, improved system reliability is obtained by making a permanent joint between pins and sockets of the disconnect plug. After the circuit has been tested, contact points may be fused through soldering, brazing, or welding.
Electrochemical Behavior of Sn-9Zn- xTi Lead-Free Solders in Neutral 0.5M NaCl Solution

Science.gov (United States)

Wang, Zhenghong; Chen, Chuantong; Jiu, Jinting; Nagao, Shijo; Nogi, Masaya; Koga, Hirotaka; Zhang, Hao; Zhang, Gong; Suganuma, Katsuaki

2018-05-01

Electrochemical techniques were employed to study the electrochemical corrosion behavior of Sn-9Zn- xTi ( x = 0, 0.05, 0.1, 0.2 wt.%) lead-free solders in neutral 0.5M NaCl solution, aiming to figure out the effect of Ti content on the corrosion properties of Sn-9Zn, providing information for the composition design of Sn-Zn-based lead-free solders from the perspective of corrosion. EIS results reveal that Ti addition was involved in the corrosion product layer and changed electrochemical interface behavior from charge transfer control process to diffusion control process. The trace amount of Ti addition (0.05 wt.%) can refine the microstructure and improve the corrosion resistance of Sn-9Zn solder, evidenced by much lower corrosion current density ( i corr) and much higher total resistance ( R t). Excess Ti addition (over 0.1 wt.%) led to the formation of Ti-containing IMCs, which were confirmed as Sn3Ti2 and Sn5Ti6, deteriorating the corrosion resistance of Sn-9Zn- xTi solders. The main corrosion products were confirmed as Sn3O(OH)2Cl2 mixed with small amount of chlorine/oxide Sn compounds.
Thermal Cycling Life Prediction of Sn-3.0Ag-0.5Cu Solder Joint Using Type-I Censored Data

Directory of Open Access Journals (Sweden)

Jinhua Mi

2014-01-01

Full Text Available Because solder joint interconnections are the weaknesses of microelectronic packaging, their reliability has great influence on the reliability of the entire packaging structure. Based on an accelerated life test the reliability assessment and life prediction of lead-free solder joints using Weibull distribution are investigated. The type-I interval censored lifetime data were collected from a thermal cycling test, which was implemented on microelectronic packaging with lead-free ball grid array (BGA and fine-pitch ball grid array (FBGA interconnection structures. The number of cycles to failure of lead-free solder joints is predicted by using a modified Engelmaier fatigue life model and a type-I censored data processing method. Then, the Pan model is employed to calculate the acceleration factor of this test. A comparison of life predictions between the proposed method and the ones calculated directly by Matlab and Minitab is conducted to demonstrate the practicability and effectiveness of the proposed method. At last, failure analysis and microstructure evolution of lead-free solders are carried out to provide useful guidance for the regular maintenance, replacement of substructure, and subsequent processing of electronic products.
Mechanical performances of lead-free solder joint connections with applications in the aerospace domain

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Georgiana PADURARU

2016-03-01

Full Text Available The paper presents some theoretical and experimental aspects regarding the tribological performances of lead-free solder joint connections, with application in the aerospace domain. In order to highlight the mechanical and tribological properties of solder joint in correlation with different pad finishes, there were made some mechanical determinations using a dedicated Share Test System. The theoretical model highlights the link between the experimental results and the influence of gravitational acceleration on the mechanical and functional integrity of the electronic assemblies that works in vibration environment. The paper novelty is provided by the interdisciplinary experiment that offers results that can be used in the mechanical, tribological, electronical and aerospace domains.
Fatigue damage modeling in solder interconnects using a cohesive zone approach

NARCIS (Netherlands)

Abdul-Baqi, A.J.J.; Schreurs, P.J.G.; Geers, M.G.D.

2005-01-01

The objective of this work is to model the fatigue damage process in a solder bump subjected to cyclic loading conditions. Fatigue damage is simulated using the cohesive zone methodology. Damage is assumed to occur at interfaces modeled through cohesive zones in the material, while the bulk material
Effect of Surface Finish of Substrate on Mechanical Reliability of in-48SN Solder Joints in Moems Package

OpenAIRE

Koo, Ja-Myeong; Jung, Seung-Boo

2007-01-01

Submitted on behalf of EDA Publishing Association (http://irevues.inist.fr/handle/2042/5920); International audience; Interfacial reactions and shear properties of the In-48Sn (in wt.%) ball grid array (BGA) solder joints after bonding were investigated with four different surface finishes of the substrate over an underlying Cu pad: electroplated Ni/Au (hereafter E-NG), electroless Ni/immersion Au (hereafter ENIG), immersion Ag (hereafter I-Ag) and organic solderability preservative (hereafte...
Crystal plasticity finite element analysis of deformation behaviour in SAC305 solder joint

Science.gov (United States)

Darbandi, Payam

Due to the awareness of the potential health hazards associated with the toxicity of lead (Pb), actions have been taken to eliminate or reduce the use of Pb in consumer products. Among those, tin (Sn) solders have been used for the assembly of electronic systems. Anisotropy is of significant importance in all structural metals, but this characteristic is unusually strong in Sn, making Sn based solder joints one of the best examples of the influence of anisotropy. The effect of anisotropy arising from the crystal structure of tin and large grain microstructure on the microstructure and the evolution of constitutive responses of microscale SAC305 solder joints is investigated. Insights into the effects of key microstructural features and dominant plastic deformation mechanisms influencing the measured relative activity of slip systems in SAC305 are obtained from a combination of optical microscopy, orientation imaging microscopy (OIM), slip plane trace analysis and crystal plasticity finite element (CPFE) modeling. Package level SAC305 specimens were subjected to shear deformation in sequential steps and characterized using optical microscopy and OIM to identify the activity of slip systems. X-ray micro Laue diffraction and high energy monochromatic X-ray beam were employed to characterize the joint scale tensile samples to provide necessary information to be able to compare and validate the CPFE model. A CPFE model was developed that can account for relative ease of activating slip systems in SAC305 solder based upon the statistical estimation based on correlation between the critical resolved shear stress and the probability of activating various slip systems. The results from simulations show that the CPFE model developed using the statistical analysis of activity of slip system not only can satisfy the requirements associated with kinematic of plastic deformation in crystal coordinate systems (activity of slip systems) and global coordinate system (shape changes
Life cycle assessment (LCA of lead-free solders from the environmental protection aspect

Directory of Open Access Journals (Sweden)

Mitovski Aleksandra M.

2009-01-01

Full Text Available Life-cycle assessment (LCA presents a relatively new approach, which allows comprehensive environmental consequences analysis of a product system over its entire life. This analysis is increasingly being used in the industry, as a tool for investigation of the influence of the product system on the environment, and serves as a protection and prevention tool in ecological management. This method is used to predict possible influences of a certain material to the environment through different development stages of the material. In LCA, the product systems are evaluated on a functionally equivalent basis, which, in this case, was 1000 cubic centimeters of an alloy. Two of the LCA phases, life-cycle inventory (LCA and life-cycle impact assessment (LCIA, are needed to calculate the environmental impacts. Methodology of LCIA applied in this analysis aligns every input and output influence into 16 different categories, divided in two subcategories. The life-cycle assessment reaserch review of the leadfree solders Sn-Cu, SAC (Sn-Ag-Cu, BSA (Bi-Sb-Ag and SABC (Sn-Ag-Bi-Cu respectively, is given in this paper, from the environmental protection aspect starting from production, through application process and finally, reclamation at the end-of-life, i.e. recycling. There are several opportunities for reducing the overall environmental and human health impacts of solder used in electronics manufacturing based on the results of the LCA, such as: using secondary metals reclaimed through post-industrial recycling; power consumption reducing by replacing older, less efficient reflow assembly equipment, or by optimizing the current equipment to perform at the elevated temperatures required for lead-free soldering, etc. The LCA analysis was done comparatively in relation to widely used Sn-Pb solder material. Additionally, the impact factors of material consumption, energy use, water and air reserves, human health and ecotoxicity have been ALSO considered including
Sutureless liver repair and hemorrhage control using laser-mediated fusion of human albumin as a solder.

Science.gov (United States)

Wadia, Y; Xie, H; Kajitani, M

2001-07-01

Major liver trauma has a high mortality because of immediate exsanguination and a delayed morbidity from septicemia, peritonitis, biliary fistulae, and delayed secondary hemorrhage. We evaluated laser soldering using liquid albumin for welding liver injuries. Fourteen lacerations (6 x 2 cm) and 13 nonanatomic resection injuries (raw surface, 8 x 2 cm) were repaired. An 805-nm laser was used to weld 53% liquid albumin-indocyanine green solder to the liver surface, reinforcing it by welding a free autologous omental scaffold. The animals were heparinized and hepatic inflow occlusion was used for vascular control. For both laceration and resection injuries, 16 soldering repairs were evaluated acutely at 3 hours. Eleven animals were evaluated chronically, two at 2 weeks and nine at 4 weeks. All 27 laser mediated-liver repairs had minimal blood loss compared with the suture controls. No dehiscence, hemorrhage, or bile leakage was seen in any of the laser repairs after 3 hours. All 11 chronic repairs healed without complication. This modality effectively seals the liver surface, joins lacerations with minimal thermal injury, and works independently of the patient's coagulation status.
Assessment of the effects of the Japanese shift to lead-free solders and its impact on material substitution and environmental emissions by a dynamic material flow analysis

International Nuclear Information System (INIS)

Fuse, Masaaki; Tsunemi, Kiyotaka

2012-01-01

Lead-free electronics has been extensively studied, whereas their adoption by society and their impact on material substitution and environmental emissions are not well understood. Through a material flow analysis (MFA), this paper explores the life cycle flows for solder-containing metals in Japan, which leads the world in the shift to lead-free solders in electronics. The results indicate that the shift has been progressing rapidly for a decade, and that substitutes for lead in solders, which include silver and copper, are still in the early life cycle stages. The results also show, however, that such substitution slows down during the late life cycle stages owing to long electronic product lifespans. This deceleration of material substitution in the solder life cycle may not only preclude a reduction in lead emissions to air but also accelerate an increase in silver emissions to air and water. As an effective measure against ongoing lead emissions, our scenario analysis suggests an aggressive recycling program for printed circuit boards that utilizes an existing recycling scheme. -- Highlights: ► We model the life cycle flows for solder-containing metals in Japan. ► The Japanese shift to lead-free solders progresses rapidly for a decade. ► Substitution for lead in solders slows down during the late life cycle stages. ► The deceleration of substitution precludes a reduction in lead emissions to air.
Impact of Alkali Source on Vitrification of SRS High Level Waste

International Nuclear Information System (INIS)

LAMBERT, D. P.; MILLER, D. H.; PEELER, D. K.; SMITH, M. E.; STONE, M. E.

2005-01-01

The Defense Waste Processing Facility (DWPF) Savannah River Site is currently immobilizing high level nuclear waste sludge by vitrification in borosilicate glass. The processing strategy involves blending a large batch of sludge into a feed tank, washing the sludge to reduce the amount of soluble species, then processing the large ''sludge batch'' through the DWPF. Each sludge batch is tested by the Savannah River National Laboratory (SRNL) using simulants and tests with samples of the radioactive waste to ''qualify'' the batch prior to processing in the DWPF. The DWPF pretreats the sludge by first acidifying the sludge with nitric and formic acid. The ratio of nitric to formic acid is adjusted as required to target a final glass composition that is slightly reducing (the target is for ∼20% of the iron to have a valence of two in the glass). The formic acid reduces the mercury in the feed to elemental mercury which is steam stripped from the feed. After a concentration step, the glass former (glass frit) is added as a 50 wt% slurry and the batch is concentrated to approximately 50 wt% solids. The feed slurry is then fed to a joule heated melter maintained at 1150 C. The glass must meet both processing (e.g., viscosity and liquidus temperature) and product performance (e.g., durability) constraints The alkali content of the final waste glass is a critical parameter that affects key glass properties (such as durability) as well as the processing characteristics of the waste sludge during the pretreatment and vitrification processes. Increasing the alkali content of the glass has been shown to improve the production rate of the DWPF, but the total alkali in the final glass is limited by constraints on glass durability and viscosity. Two sources of alkali contribute to the final alkali content of the glass: sodium salts in the waste supernate and sodium and lithium oxides in the glass frit added during pretreatment processes. Sodium salts in the waste supernate can
Tin-silver and tin-copper alloys for capillarity joining-soft soldering-of copper piping

International Nuclear Information System (INIS)

Duran, J.; Amo, J. M.; Duran, C. M.

2001-01-01

It is studied the influence of the type of alloy used as filling material on the defects of the soldering joints in copper piping installations, which induce the fluid leak of the systems. The different eutectic temperatures and solidus-liquidus ranges of these alloys, require the setting of the soldering heat input in each case to obtain the suitable capillarity features and alloying temperatures to achieve for the correct formation of the bonding. Most defects in the joints are demonstrated to be generated by bad dossification of thermal inputs, which led depending on the filler alloy used to variations in its fluidity that may produce penetration failures in the bonds or insufficient consistency for the filling of the joints. (Author) 7 refs
Estudo colorimétrico de fritas feldspáticas Colorimetric study of feldsphatic frits

Directory of Open Access Journals (Sweden)

S. F Santos

2010-03-01

Full Text Available As fritas cerâmicas são materiais de natureza vítrea preparadas por fusão em temperaturas elevadas (~1500 ºC, a partir de uma mistura de matérias-primas minerais. Os vidrados preparados exclusivamente a partir de fritas são utilizados principalmente em peças cerâmicas nas quais a componente estética é mais importante que a componente técnica, como no caso de azulejos, objetos decorativos e em restaurações odontológicas. Para um efeito decorativo mais eficiente, é necessário que o revestimento cerâmico seja estável o suficiente para não alterar significativamente a cor apresentada pelo pigmento e, dessa forma, possibilitar uma reprodutibilidade da cor obtida. Nesse contexto, este trabalho mostra um estudo de cor desenvolvida por pigmentos cerâmicos em fritas transparentes, obtidas a partir de feldspato da região Borborema-Seridó (PB/RN. A análise química do feldspato evidenciou que este mineral cumpre os requisitos necessários à aplicação como cerâmica (ou vidrado de cobertura, pois apresenta teores mínimos de impurezas (minerais portadores de ferro e outros óxidos corantes que deterioram a qualidade da frita obtida. O mineral foi caracterizado ainda por difração de raios X (albita e monoclínio e quanto à granulometria (abaixo de 100 µm. A avaliação colorimétrica de acordo com os padrões CIElab e por medidas de refletância possibilitou caracterização da cor dos revestimentos obtidos em diferente fontes e iluminantes. Os resultados permitiram avaliar que o feldspato do Seridó apresenta potencial para aplicação como revestimento cerâmico colorido e futuramente poderia ser aplicado na área de restauração cerâmica odontológica, tendo em vista que esse mineral é um dos principais componentes das porcelanas odontológicas, porém, até o presente, todo material de restauração odontológica utilizado no Brasil é de origem estrangeira.Ceramic frits are vitreous materials prepared by melting of

Intense generation of respirable metal nanoparticles from a low-power soldering unit

Energy Technology Data Exchange (ETDEWEB)

Gómez, Virginia [Department of Chemical Engineering, Nanoscience Institute of Aragon (INA), 50018 Zaragoza (Spain); Irusta, Silvia [Department of Chemical Engineering, Nanoscience Institute of Aragon (INA), 50018 Zaragoza (Spain); Networking Biomedical Research Center of Bioengineering, Biomaterials and Nanomedicine (CIBER-BBN), 50018 Zaragoza (Spain); Balas, Francisco [Networking Biomedical Research Center of Bioengineering, Biomaterials and Nanomedicine (CIBER-BBN), 50018 Zaragoza (Spain); Instituto de Carboquímica – Consejo Superior de Investigaciones Científicas (ICB-CSIC), 50018 Zaragoza (Spain); Santamaria, Jesus, E-mail: Jesus.Santamaria@unizar.es [Department of Chemical Engineering, Nanoscience Institute of Aragon (INA), 50018 Zaragoza (Spain); Networking Biomedical Research Center of Bioengineering, Biomaterials and Nanomedicine (CIBER-BBN), 50018 Zaragoza (Spain)

2013-07-15

Highlights: • Intense generation of nanoparticles in the breathing range from a flux-soldering unit is detected. • Coagulation in the aerosol phase leads to 200-nm respirable nanoparticles up to 30 min after operation. • Nanoparticle concentration in the working environment depends on the presence of ambient air. • Metal-containing nanoparticles are collected in TEM grids and filters in the hundreds of nanometer range. -- Abstract: Evidence of intense nanoparticle generation from a low power (45 W) flux soldering unit is presented. This is a familiar device often used in daily life, including home repairs and school electronic laboratories. We demonstrate that metal-containing nanoparticles may reach high concentrations (ca. 10{sup 6} particles/cm{sup 3}) within the breathing range of the operator, with initial size distributions centered at 35–60 nm The morphological and chemical analysis of nanoparticle agglomerates collected on TEM grids and filters confirms their multiparticle structure and the presence of metals.
Intense generation of respirable metal nanoparticles from a low-power soldering unit

International Nuclear Information System (INIS)

Gómez, Virginia; Irusta, Silvia; Balas, Francisco; Santamaria, Jesus

2013-01-01

Highlights: • Intense generation of nanoparticles in the breathing range from a flux-soldering unit is detected. • Coagulation in the aerosol phase leads to 200-nm respirable nanoparticles up to 30 min after operation. • Nanoparticle concentration in the working environment depends on the presence of ambient air. • Metal-containing nanoparticles are collected in TEM grids and filters in the hundreds of nanometer range. -- Abstract: Evidence of intense nanoparticle generation from a low power (45 W) flux soldering unit is presented. This is a familiar device often used in daily life, including home repairs and school electronic laboratories. We demonstrate that metal-containing nanoparticles may reach high concentrations (ca. 10 6 particles/cm 3 ) within the breathing range of the operator, with initial size distributions centered at 35–60 nm The morphological and chemical analysis of nanoparticle agglomerates collected on TEM grids and filters confirms their multiparticle structure and the presence of metals
Liver repair and hemorrhage control using laser soldering of liquid albumin in a porcine model

Science.gov (United States)

Wadia, Yasmin; Xie, Hua; Kajitani, Michio; Gregory, Kenton W.; Prahl, Scott A.

2000-05-01

The purpose of this study was to evaluate laser soldering using liquid albumin for welding liver lacerations and sealing raw surfaces created by segmental resection of a lobe. Major liver trauma has a high mortality due to immediate exsanguination and a delayed morbidity and mortality from septicemia, peritonitis, biliary fistulae and delayed secondary hemorrhage. Eight laceration injuries (6 cm long X 2 cm deep) and eight non-anatomical resection injuries (raw surface 6 cm X 2 cm) were repaired. An 805 nm laser was used to weld 53% liquid albumin-ICG solder to the liver surface, reinforcing it with a free autologous omental scaffold. The animals were heparinized to simulate coagulation failure and hepatic inflow occlusion was used for vascular control. For both laceration and resection injuries, eight soldering repairs each were evaluated at three hours. A single suture repair of each type was evaluated at three hours. All 16 laser mediated liver repairs were accompanied by minimal blood loss as compared to the suture controls. No dehiscence, hemorrhage or bile leakage was seen in any of the laser repairs after three hours. In conclusion laser fusion repair of the liver is a quick and reliable technique to gain hemostasis on the cut surface as well as weld lacerations.
Microstructure and mechanical properties of Sn-9Zn-xAl2O3 nanoparticles (x=0–1) lead-free solder alloy: First-principles calculation and experimental research

International Nuclear Information System (INIS)

Xing, Wen-qing; Yu, Xin-ye; Li, Heng; Ma, Le; Zuo, Wei; Dong, Peng; Wang, Wen-xian; Ding, Min

2016-01-01

This paper studies microstructure and mechanical properties of Sn-9Zn-x Al 2 O 3 nanoparticles (x=0–1) lead-free solder alloy. The interface structure, interface energy and electronic properties of Al 2 O 3 /Sn9Zn interface are investigated by first-principle calculation. On the experimental part, in comparison with the plain Sn-9Zn solder, the Al 2 O 3 nanoparticles incorporated into the solder matrix can inhibit the growth of coarse dendrite Sn-Zn eutectic structure and refine grains of the composite solders during the solidification process of the alloys. Moreover, the microhardness and average tensile strength of the solders with addition of Al 2 O 3 nanoparticles increased with the increasing weight percentages of Al 2 O 3 nanoparticles. These improved mechanical properties can be attributed to the microstructure developments and the dispersed Al 2 O 3 nanoparticles.
Behavior of Sn-0.7Cu-xZn lead free solder on physical properties and micro structure

Science.gov (United States)

Siahaan, Erwin

2017-09-01

The issues to substitute Tin-Lead Solders is concerning the health and environmental hazards that is caused by lead, and also legislative actions around the world regarding lead toxicity, which has prompted the research community to attempt to replace solder alloys for the traditional Sn-Pb alloys lead which has been used by industrial worker throughout history because it is easily extracted and refined at a relatively low energy cost and also has a range of useful properties. Traditional industry lead has been used in soldering materials for electronic applications because it has low melting point and a soft, malleable nature, when combined with tin at the eutectic composition which causes the alloy to flow easily in the liquid state and solidifies over a very small range of temperature. One of the potential candidate to replace tin-lead solder is Sn-Cu-Zn eutectic alloy as it has a lower melting temperature. Consequently, it is of interest to determine what reactions can occur in ternary systems derived from the Sn-Cu-Zn eutectic. One such system is Sn-0.7Cu-xZn. The specimen was elaborated on physical properties. The chemical content was analyzed by using Shimadzu XRD and melting point was analyzed by using Differential Scanning Calorimeter ( DSC ). The results has shown that the highest addition of Zinc content (15%Zn) will decrease the melting temperatur to 189°C compared to Sn-Pb at 183°C Increasing the amount of Zn on Sn0.7Cu-xZn alloys will decrease Cu3Sn intermetallic coumpound.
Appendix to the report from the low-residue soldering task force: Phase 2 results

Energy Technology Data Exchange (ETDEWEB)

Iman, R.L.; Anderson, D.J.; Huffman, D.D. [and others

1995-12-01

The LRSTF report for Phase I of its evaluation of low-residue soldering was issued in June 1995. This Appendix summarizes the results of follow-on testing performed in Phase II and compares electrical test results for both phases. Deliberate decisions were made by the LRSTF in Phase I to challenge the design guideline limits in MILSTD-275, Printed Wiring for Electronic Equipment The LRSTF considered this approach to produce a ``worst case`` design and provide useful information about the robustness of LR soldering processes. As such, good design practices were sometimes deliberately violated in designing the LRSTF board. This approach created some anomalies for both LR boards and RMA/cleaned controls. Phase II testing verified that problems that affected both RMA/cleaned and LR boards in Phase I were design related.
Effect of laser wavelength and protein solder concentration on acute tissue repair using laser welding: initial results in a canine ureter model.

Science.gov (United States)

Wright, E J; Poppas, D P

1997-01-01

Successful tissue approximation can be performed using low power laser energy combined with human albumin solder. In vitro studies were undertaken to investigate the acute repair strengths achieved using different laser wavelengths. Furthermore, we evaluated the change in repair strength with that resulted from changes in protein solder concentration. Intraluminal bursting pressure following ureterotomy repair was measured for the following laser wavelengths: 532, 808, 1,320, 2,100, and 10,600 nm. The tissue absorption characteristics of the 808-nm diode and the KTP-532-nm lasers required the addition of the exogenous chromophores indocyanine green and fluorescein, respectively. A 40% human albumin solder was incorporated in the repair of a 1.0-cm longitudinal defect in the canine ureter. Following determination of an optimal welding wavelength, human albumin solder of varying concentrations (25%, 38%, 45%, and 50%) were prepared and tested. The 1,320-nm YAG laser achieved the highest acute bursting pressure and was the most effective in this model. Of the concentrations of albumin tested, 50% human albumin yielded the greatest bursting pressures. We conclude that of the laser wavelengths evaluated, the 1,320-nm YAG achieves the strongest tissue weld in the acute ex vivo dog ureter model. In addition, when this laser system is used, the acute strength of a photothermal weld appears to be directly proportional to the concentration of human albumin solder in the range of 25 to 50%.
Reductions in Aprotic Media. I. Cathodic Reduction Limits in Acetonitrile at a Platinum Electrode.

Science.gov (United States)

1981-08-15

specifically; (1) The difference in the effect of water on lithium solutions and tetraalkylammonium solutions, (2) the passivation of a platinum electrode...solutions. 5 EXPERIMENTAL Procedure for Controlled Potential Electrolysis The electrolyses were performed in a glass H-cell. The anode and cathode...fine porous glass frit from the Luggin section. The electrolyses were run in constant potential mode. After electrolysis, the catholyte was removed and
Influence of ZnO nano-particles addition on thermal analysis, microstructure evolution and tensile behavior of Sn–5.0 wt% Sb–0.5 wt% Cu lead-free solder alloy

Energy Technology Data Exchange (ETDEWEB)

Fouda, A.N., E-mail: alynabieh@yahoo.com [Physics Department, Faculty of Science, Suez-Canal University, 41522 Ismailia (Egypt); Eid, E.A., E-mail: dr_eid_hti@yahoo.com [Basic Science Department, Higher Technological Institute, 44629 10th of Ramadan City (Egypt)

2015-04-24

Sn–5 wt%Sb–0.5 wt%Cu (plain SSC505) and Sn–5 wt%Sb–0.5 wt%Cu–0.5 wt% ZnO (SSC-ZnO) composite solder alloys have been studied. The variation in thermal behavior, microstructure and tensile characteristics associated with mixing of 0.5 wt% ZnO nano-metric particles to plain SSC505 solder were investigated. A slight increment in the melting temperature [ΔT{sub m}=0.89 °C] was recorded using differential scanning calorimetry (DSC) after addition of ZnO. X-Ray diffraction (XRD) analysis confirmed the existence of β-Sn, SbSn and Cu{sub 6}Sn{sub 5} intermetallic compounds (IMCs) beside some of ZnO planes in SSC-ZnO composite solder. Field emission scanning electronic microscope (FE-SEM) investigation of SSC-ZnO composite solder revealed a homogenous uniform distribution, size refinement of IMCs and β-Sn grains. Addition of ZnO nano-metric particles into the plain SSC505 enhanced the yield stress σ{sub YS} by ~12% and improved the ultimate tensile strength σ{sub UTS} by ~13%. In addition, adding ZnO nano-metric particles was found to be effective for reducing ductility by ~43% of the plain solder due to the refinement of β-Sn grains within SSC-ZnO composite solder. - Highlights: • Melting point of SSC505-ZnO composite solder is slightly increased by 0.89 {sup ο}C compared with the plain SSC505 solder. • XRD and EDX analysis reflect the presence of SbSn, Cu{sub 6}Sn{sub 5} IMCs. • EF-SEM images of SSC-ZnO composite solder revealed homogenous uniform distribution of β-Sn grains and fine IMC particles. • A detectable improvement in the Young modulus, ultimate tensile strength and yield strength were observed after addition of 0.5 wt% ZnO nano-metric particles.
Controlling Vapor Pressure In Hanging-Drop Crystallization

Science.gov (United States)

Carter, Daniel C.; Smith, Robbie

1988-01-01

Rate of evaporation adjusted to produce larger crystals. Device helps to control vapor pressure of water and other solvents in vicinity of hanging drop of solution containing dissolved enzyme protein. Well of porous frit (sintered glass) holds solution in proximity to drop of solution containing protein or enzyme. Vapor from solution in frit controls evaporation of solvent from drop to control precipitation of protein or enzyme. With device, rate of nucleation limited to decrease number and increase size (and perhaps quality) of crystals - large crystals of higher quality needed for x-ray diffraction studies of macromolecules.
Study of silicon chip soldering in high-power transistor housing

Directory of Open Access Journals (Sweden)

Vasily S. Anosov

2017-09-01

We experimentally assessed the effect of outer housing layer materials and back side chip metallization. For lead-silver soldering of silicon chips, the best housing is that with a nickel outer layer rather than with a gold-plated one, because the resultant thermal resistance is lower and the absence of gold makes the technology cheaper. We obtained a 0.6 K/W thermal resistance for a 24 mm2 chip area.
The micro-droplet behavior of a molten lead-free solder in an inkjet printing process

International Nuclear Information System (INIS)

Tsai, M H; Chou, H H; Hwang, W S

2009-01-01

An experimental investigation on the droplet formation of molten Sn3.0 wt%Ag0.5 wt%Cu alloy by an inkjet printing process was conducted. The printing process used a piezoelectric print head with a nozzle orifice diameter of 50 µm. Micro-droplets of a molten lead-free solder were ejected at 230 °C. The print head was driven by a bipolar pulse 40 V in amplitude. The major variables for this study were two pulse times; t rise /t finalrise and t fall , as well as N 2 back-pressure in the molten solder reservoir. Under various printing conditions, extrusion of the liquid column, contraction of liquid thread and pinch-off of liquid thread at nozzle exit were observed by monitoring the dynamics of the molten solder droplet ejection process. The droplet formation was found to be insensitive to t rise and t finalrise in the range of 250–1000 µs. The behavior of droplet formation was, however, significantly affected by the transfer rate, t fall , in the range of 30–60 µs and t fall of 50 µs yielded the most desirable condition of single droplet formation. The N 2 back-pressure was also found to be critical, where a back pressure between 10 and 21 kPa could give the desirable single-droplet formation condition
The Effect of Wetting Gravity Regime on Shear Strength of SAC and Sn-Pb Solder Lap Joints

Science.gov (United States)

Sona, Mrunali; Prabhu, K. Narayan

2017-09-01

The failure of solder joints due to imposed stresses in an electronic assembly is governed by shear bond strength. In the present study, the effect of wetting gravity regime on single-lap shear strength of Sn-0.3Ag-0.7Cu and Sn-2.5Ag-0.5Cu solder alloys reflowed between bare copper substrates as well as Ni-coated Cu substrates was investigated. Samples were reflowed for 10 s, T gz (time corresponding to the end of gravity regime) and 100 s individually and tested for single-lap shear strength. The single-lap shear test was also carried out on eutectic Sn-Pb/Cu- and Sn-Pb/Ni-coated Cu specimens to compare the shear strength values obtained with those of lead-free alloys. The eutectic Sn-Pb showed significantly higher ultimate shear strength on bare Cu substrates when compared to Sn-Ag-Cu alloys. However, SAC alloys reflowed on nickel-coated copper substrate exhibited higher shear strength when compared to eutectic Sn-Pb/Ni-coated Cu specimens. All the substrate/solder/substrate lap joint specimens that were reflowed for the time corresponding to the end of gravity regime exhibited maximum ultimate shear strength.
Understanding the influence of tellurium oxide in front Ag paste for contacting silicon solar cells with homogeneous high sheet resistance emitter

Science.gov (United States)

Ebong, Abasifreke; Bezawada, Nirupama; Batchu, Kartheek

2017-08-01

This paper investigates TeO2, one of the front Ag paste additives, to understand its role in low contact and gridline resistances for screen-printed Si solar cell. It is concluded that TeO2 aids the reduction of molten glass frit viscosity during contact co-firing. This in turn, leads to uniform flow of molten glass frit, both in the gridline bulk and interface of gridline and SiN x . Therefore, the uniform wetting and etching of SiN x and consequently larger contact area of metal to Si compared to its counterpart without TeO2. Hence, the current transport mechanism from Si to gridline can be said to be both direct and tunneling. The Raman spectra showed a blue shift in the phase of the TeO2 after contact co-firing in the gridline bulk confirming a crystalline γ-TeO2.
Effect of nano Ni additions on the structure and properties of Sn-9Zn and Sn-Zn-3Bi solders in Au/Ni/Cu ball grid array packages

Energy Technology Data Exchange (ETDEWEB)

Gain, Asit Kumar [Department of Electronic Engineering, City University of Hong Kong, Tat Chee Avenue, Kowloon Tong (Hong Kong); Chan, Y.C. [Department of Electronic Engineering, City University of Hong Kong, Tat Chee Avenue, Kowloon Tong (Hong Kong)], E-mail: eeycchan@cityu.edu.hk; Yung, Winco K.C. [Department of Industrial and Systems Engineering, The Hong Kong Polytechnic University, Hung Hom, Kowloon (Hong Kong)

2009-05-25

The effect of nano Ni additions in Sn-9Zn and Sn-8Zn-3Bi solders on their interfacial microstructures and shear loads with Au/Ni/Cu pad metallization in ball grid array (BGA) applications were investigated. After the addition of nano Ni powder in Sn-based lead-free solders, there were no significant changes in the interfacial microstructure. But, in the solder region a very fine Zn-rich phase was observed. Also on the fracture surfaces a fine Zn-Ni compound was found. After the addition of nano Ni powder in Sn-based solders, the shear loads were increased due to a refinement of the microstructure and in addition, ductile fracture surfaces were clearly observed. The shear loads of the plain Sn-9Zn and Sn-8Zn-3Bi solders after one reflow cycle were about 1798 g and 2059 g, respectively. After the addition of nano Ni powder, their loads were about 2172 g and 2212 g, respectively, after one reflow cycle and their shear loads after eight reflow cycles were about 2099 g and 2081 g, respectively.
Effect of nano Ni additions on the structure and properties of Sn-9Zn and Sn-Zn-3Bi solders in Au/Ni/Cu ball grid array packages

International Nuclear Information System (INIS)

Gain, Asit Kumar; Chan, Y.C.; Yung, Winco K.C.

2009-01-01

The effect of nano Ni additions in Sn-9Zn and Sn-8Zn-3Bi solders on their interfacial microstructures and shear loads with Au/Ni/Cu pad metallization in ball grid array (BGA) applications were investigated. After the addition of nano Ni powder in Sn-based lead-free solders, there were no significant changes in the interfacial microstructure. But, in the solder region a very fine Zn-rich phase was observed. Also on the fracture surfaces a fine Zn-Ni compound was found. After the addition of nano Ni powder in Sn-based solders, the shear loads were increased due to a refinement of the microstructure and in addition, ductile fracture surfaces were clearly observed. The shear loads of the plain Sn-9Zn and Sn-8Zn-3Bi solders after one reflow cycle were about 1798 g and 2059 g, respectively. After the addition of nano Ni powder, their loads were about 2172 g and 2212 g, respectively, after one reflow cycle and their shear loads after eight reflow cycles were about 2099 g and 2081 g, respectively.
Effect of nano Co reinforcements on the structure of the Sn-3.0Ag-0.5Cu solder in liquid and after reflow solid states

Energy Technology Data Exchange (ETDEWEB)

Yakymovych, Andriy, E-mail: yakymovych@univie.ac.at [Department of Inorganic Chemistry – Functional Materials, University of Vienna, Währinger Str. 42, 1090 Vienna (Austria); Department of Metal Physics, Ivan Franko National University of Lviv, Kyrylo i Mephodiy Str. 8, 79005 Lviv (Ukraine); Mudry, Stepan; Shtablavyi, Ihor [Department of Metal Physics, Ivan Franko National University of Lviv, Kyrylo i Mephodiy Str. 8, 79005 Lviv (Ukraine); Ipser, Herbert [Department of Inorganic Chemistry – Functional Materials, University of Vienna, Währinger Str. 42, 1090 Vienna (Austria)

2016-09-15

Sn-Ag-Cu (SAC) alloys are commonly recognized as lead-free solders employed in the electronics industry. However, some disadvantages in mechanical properties and their higher melting temperatures compared to Pb-Sn solders prompt new research relating to reinforcement of existing SAC solders. One of the ways to reinforce these solder materials is the formation of composites with nanoparticles as filler materials. Accordingly, this study presents structural features of nanocomposite (Sn-3.0Ag-0.5Cu){sub 100−x}(nanoCo){sub x} solders with up to 0.8 wt% nano Co. The effect of nano-sized Co particles was investigated by means of differential thermal analysis (DTA), X-ray diffraction (XRD) in both liquid and solid states, and scanning electron microscopy (SEM). The experimental data of DTA are compared with available literature data for bulk Sn-3.0Ag-0.5Cu alloy to check the capability of minor nano-inclusions to decrease the melting temperature of the SAC solder. The combination of structural data in liquid and solid states provides important information about the structural transformations of liquid Sn-3.0Ag-0.5Cu alloys caused by minor Co additions and the phase formation during crystallization. Furthermore, scanning electron microscopy has shown the mutual substitution of Co and Cu atoms in the Cu{sub 6}Sn{sub 5} and CoSn{sub 3} phases, respectively. - Highlights: • Differential thermal analysis of nanocomposite (Sn-3.0Ag-0.5Cu){sub 100−x}(nanoCo){sub x} alloys. • Structural transformations of liquid Sn-3.0Ag-0.5Cu solder by minor Co additions. • Structure data of the solid quaternary (Sn-3.0Ag-0.5Cu){sub 100−x}(Co){sub x} alloys. • Substitution of Co and Cu atoms in the Cu{sub 6}Sn{sub 5} and CoSn{sub 3} phases.
A FPGA implementation of solder paste deposit on printed circuit boards errors detector based in a bright and contrast algorithm

OpenAIRE

De Luca-Pennacchia, A.; Sánchez-Martínez, M. Á.

2007-01-01

Solder paste deposit on printed circuit boards (PCB) is a critical stage. It is known that about 60% of functionality defects in this type of boards are due to poor solder paste printing. These defects can be diminished by means of automatic optical inspection of this printing. Actually, this process is implemented by image processing software with its inherent high computational time cost. In this paper we propose to implement a high parallel degree image comparison algorithm suitable to be ...
The thermodynamic database COST MP0602 for materials for high-temperature lead-free soldering

Czech Academy of Sciences Publication Activity Database

Kroupa, Aleš; Dinsdale, A.; Watson, A.; Vřešťál, J.; Zemanová, Adéla; Brož, P.

2012-01-01

Roč. 48, č. 3 (2012), s. 339-346 ISSN 1450-5339 R&D Projects: GA MŠk LD11024 Institutional support: RVO:68081723 Keywords : CALPHAD method * lead-free solders * thermodynamic database Subject RIV: BJ - Thermodynamics Impact factor: 1.435, year: 2012
Microstructure and mechanical properties of Sn-9Zn-xAl{sub 2}O{sub 3} nanoparticles (x=0–1) lead-free solder alloy: First-principles calculation and experimental research

Energy Technology Data Exchange (ETDEWEB)

Xing, Wen-qing; Yu, Xin-ye; Li, Heng; Ma, Le; Zuo, Wei [Taiyuan University of Technology, College of Material Science and Technology, Taiyuan 030024 (China); Dong, Peng; Wang, Wen-xian [Taiyuan University of Technology, College of Material Science and Technology, Taiyuan 030024 (China); Shanxi Key Laboratory of Advanced Magnesium-based Materials, Taiyuan 030024 (China); Key Laboratory of Interface Science and Engineering in Advanced Materials, Ministry of Education, Taiyuan University of Technology, Taiyuan 030024 (China); Ding, Min, E-mail: dingmin@tyut.edu.cn [Taiyuan University of Technology, College of Material Science and Technology, Taiyuan 030024 (China); Shanxi Key Laboratory of Advanced Magnesium-based Materials, Taiyuan 030024 (China); Key Laboratory of Interface Science and Engineering in Advanced Materials, Ministry of Education, Taiyuan University of Technology, Taiyuan 030024 (China)

2016-12-15

This paper studies microstructure and mechanical properties of Sn-9Zn-x Al{sub 2}O{sub 3} nanoparticles (x=0–1) lead-free solder alloy. The interface structure, interface energy and electronic properties of Al{sub 2}O{sub 3}/Sn9Zn interface are investigated by first-principle calculation. On the experimental part, in comparison with the plain Sn-9Zn solder, the Al{sub 2}O{sub 3} nanoparticles incorporated into the solder matrix can inhibit the growth of coarse dendrite Sn-Zn eutectic structure and refine grains of the composite solders during the solidification process of the alloys. Moreover, the microhardness and average tensile strength of the solders with addition of Al{sub 2}O{sub 3} nanoparticles increased with the increasing weight percentages of Al{sub 2}O{sub 3} nanoparticles. These improved mechanical properties can be attributed to the microstructure developments and the dispersed Al{sub 2}O{sub 3} nanoparticles.

FY 1998 report on the waste processing/recycling related technology, 'The R and D of lead-free solder standardization'; 1998 nendo haikibutsu shori recycle kanren gijutsu seika hokokusho. Namari free handa kikakuka nado kenkyu kaihatsu

Energy Technology Data Exchange (ETDEWEB)

NONE

2000-03-01

To reduce the environmental pollution caused by lead eluted from the electronic equipment waste, the R and D on lead-free solder were conducted and the results were summarized. As to the basic characteristics, the evaluation test method was studied in terms of the range of melting temperature, mechanical strength, wettability and joint strength, to select a uniform test method. As the lead-free solder, Sn-Ag alloys were mainly used and mixed in a combination of Cu, Bi and In. Changes in characteristics were made clear by adding trace elements such as Ge, Mn and P. Relating to the applied characteristics, in selection of solder materials, materials were selected for which evaluation of the commercialization is proceeded with from a viewpoint of promotion of commercialization. Concerning the experimental evaluation of characteristics of lead-free solder in mounted substrates, it was indicated that basically lead-free solder can be practically used. Further, it was indicated that the Sn-Ag-Cu-Bi system depends not on solder composition but on active force, printing accuracy and flux characteristic of solder paste, that improvement of solder paste has an effect on mounting characteristics. (NEDO)
Reliability of Wind Turbine Components-Solder Elements Fatigue Failure

DEFF Research Database (Denmark)

Kostandyan, Erik; Sørensen, John Dalsgaard

2012-01-01

on the temperature mean and temperature range. Constant terms and model errors are estimated. The proposed methods are useful to predict damage values for solder joint in power electrical components. Based on the proposed methods it is described how to find the damage level for a given temperature loading profile....... The proposed methods are discussed for application in reliability assessment of Wind Turbine’s electrical components considering physical, model and measurement uncertainties. For further research it is proposed to evaluate damage criteria for electrical components due to the operational temperature...
Electrochemical migration of lead-free solder alloys in Na2SO4 environment

DEFF Research Database (Denmark)

Medgyes, Balint; Ádám, Sándor; Tar, Lajos

2017-01-01

The effect of sulphate ion concentration on electrochemical migration of lead-free solder alloys was investigated with the use of water drop tests, by applying an in-situ optical and electrical inspection system. According to the Mean-Time-To-Failure (MTTF) values it was found that in the case of...
MAR Assessments Of The High Level Waste System Plan Revision 16

International Nuclear Information System (INIS)

Peeler, D.; Edwards, T.

2011-01-01

which a glass system (i.e., a projected sludge composition with a candidate frit) is predicted to be acceptable can be defined (i.e., the projected operating window) which will provide insight into the ability to meet future contractual WL obligations. In this study, future contractual WL obligations are assumed to be 40%, which is the goal after all flowsheet enhancements have been implemented to support DWPF operations. For a system to be considered acceptable, candidate frits must be identified that provide access to at least 40% WL while accounting for potential variation in the sludge resulting from differences in batch-to-batch transfers into the Sludge Receipt and Adjustment Tank (SRAT) and/or analytical uncertainties. In more general terms, this study will assess whether or not the current glass formulation strategy (based on the use of the Nominal and Variation Stage assessments) and current PCCS models will allow access to compositional regions required to targeted higher WLs for future operations. Some of the key questions to be considered in this study include: (1) If higher WLs are attainable with current process control models, are the models valid in these compositional regions? If the higher WL glass regions are outside current model development or validation ranges, is there existing data that could be used to demonstrate model applicability (or lack thereof)? If not, experimental data may be required to revise current models or serve as validation data with the existing models. (2) Are there compositional trends in frit space that are required by the PCCS models to obtain access to these higher WLs? If so, are there potential issues with the compositions of the associated frits (e.g., limitations on the B 2 O 3 and/or Li 2 O concentrations) as they are compared to model development/validation ranges or to the term 'borosilicate' glass? If limitations on the frit compositional range are realized, what is the impact of these restrictions on other glass
Effect of Ni addition to the Cu substrate on the interfacial reaction and IMC growth with Sn3.0Ag0.5Cu solder

Science.gov (United States)

Zhang, Xudong; Hu, Xiaowu; Jiang, Xiongxin; Li, Yulong

2018-04-01

The formation and growth of intermetallic compound (IMC) layer at the interface between Sn3.0Ag0.5Cu (SAC305) solder and Cu- xNi ( x = 0, 0.5, 1.5, 5, 10 wt%) substrate during reflowing and aging were investigated. The soldering was conducted at 270 °C using reflowing method, following by aging treatment at 150 °C for up to 360 h. The experimental results indicated that the total thickness of IMC increased with increasing aging time. The scallop-like Cu6Sn5 and planar-like Cu3Sn IMC layer were observed between SAC305 solder and purely Cu substrate. As the content of Ni element in Cu substrate was 0.5% or 1.5%, the scallop-like Cu6Sn5 and planar-like Cu3Sn IMC layer were still found between solder and Cu-Ni substrate and the total thickness of IMC layer decreased with the increasing Ni content. Besides, when the Ni content was up to 5%, the long prismatic (Cu,Ni)6Sn5 phase was the only product between solder and substrate and the total thickness of IMC layer increased significantly. Interestingly, the total thickness of IMC decreased slightly as the Ni addition was up to 10%. In the end, the grains of interfacial IMC layer became coarser with aging time increasing while the addition of Ni in Cu substrate could refine IMC grains.
An experimental study on Sodalite and SAP matrices for immobilization of spent chloride salt waste

Science.gov (United States)

Giacobbo, Francesca; Da Ros, Mirko; Macerata, Elena; Mariani, Mario; Giola, Marco; De Angelis, Giorgio; Capone, Mauro; Fedeli, Carlo

2018-02-01

In the frame of Generation IV reactors a renewed interest in pyro-processing of spent nuclear fuel is underway. Molten chloride salt waste arising from the recovering of uranium and plutonium through pyro-processing is one of the problematic wastes for direct application of vitrification or ceramization. In this work, Sodalite and SAP have been evaluated and compared as potential matrices for confinement of spent chloride salt waste coming from pyro-processing. To this aim Sodalite and SAP were synthesized both in pure form and mixed with different glass matrices, i.e. commercially available glass frit and borosilicate glass. The confining matrices were loaded with mixed chloride salts to study their retention capacities with respect to the elements of interest. The matrices were characterized and leached for contact times up to 150 days at room temperature and at 90 °C. SEM analyses were also performed in order to compare the matrix surface before and after leaching. Leaching results are discussed and compared in terms of normalized releases with similar results reported in literature. According to this comparative study the SAP matrix with glass frit binder resulted in the best matrix among the ones studied, with respect to retention capacities for both matrix and spent fuel elements.
Complications with computer-aided designed/computer-assisted manufactured titanium and soldered gold bars for mandibular implant-overdentures: short-term observations.

Science.gov (United States)

Katsoulis, Joannis; Wälchli, Julia; Kobel, Simone; Gholami, Hadi; Mericske-Stern, Regina

2015-01-01

Implant-overdentures supported by rigid bars provide stability in the edentulous atrophic mandible. However, fractures of solder joints and matrices, and loosening of screws and matrices were observed with soldered gold bars (G-bars). Computer-aided designed/computer-assisted manufactured (CAD/CAM) titanium bars (Ti-bars) may reduce technical complications due to enhanced material quality. To compare prosthetic-technical maintenance service of mandibular implant-overdentures supported by CAD/CAM Ti-bar and soldered G-bar. Edentulous patients were consecutively admitted for implant-prosthodontic treatment with a maxillary complete denture and a mandibular implant-overdenture connected to a rigid G-bar or Ti-bar. Maintenance service and problems with the implant-retention device complex and the prosthesis were recorded during minimally 3-4 years. Annual peri-implant crestal bone level changes (ΔBIC) were radiographically assessed. Data of 213 edentulous patients (mean age 68 ± 10 years), who had received a total of 477 tapered implants, were available. Ti-bar and G-bar comprised 101 and 112 patients with 231 and 246 implants, respectively. Ti-bar mostly exhibited distal bar extensions (96%) compared to 34% of G-bar (p overdentures supported by soldered gold bars or milled CAD/CAM Ti-bars are a successful treatment modality but require regular maintenance service. These short-term observations support the hypothesis that CAD/CAM Ti-bars reduce technical complications. Fracture location indicated that the titanium thickness around the screw-access hole should be increased. © 2013 Wiley Periodicals, Inc.
Electromigration in 3D-IC scale Cu/Sn/Cu solder joints

Energy Technology Data Exchange (ETDEWEB)

Ho, Cheng-En, E-mail: ceho1975@hotmail.com; Lee, Pei-Tzu; Chen, Chih-Nan; Yang, Cheng-Hsien

2016-08-15

The electromigration effect on the three-dimensional integrated circuits (3D-IC) scale solder joints with a Cu/Sn(25–50 μm)/Cu configuration was investigated using a field-emission scanning electron microscope (FE–SEM) combined with electron backscatter diffraction (EBSD) analysis system. Electron current stressing for a few days caused the pronounced accumulation of Cu{sub 6}Sn{sub 5} in specific Sn grain boundaries (GBs). The EBSD analysis indicated that both the β-Sn crystallographic orientation and GB orientation play dominant roles in this accumulation. The dependencies of the Cu{sub 6}Sn{sub 5} accumulation on the two above factors (i.e., Sn grain orientation and GB orientation) can be well rationalized via a proposed mathematic model based on the Huntington and Grone's electromigration theory with the Cu anisotropic diffusion data in a β-Sn lattice. - Highlights: • Anisotropic Cu electromigration in the 3D-IC scale microelectronic solder joints. • Pronounced accumulation of Cu{sub 6}Sn{sub 5} intermetallic in specific Sn grain boundaries. • A linear dependence of Cu{sub 6}Sn{sub 5} accumulation over the current stressing time. • β-Sn and grain boundary orientations are the dominant factors in Cu{sub 6}Sn{sub 5} accumulation.
Minimizing lead release levels in secondary smelters slags

International Nuclear Information System (INIS)

Shenkler, E.S.; Graham, S.; Ghosh, R.; Greenhut, V.A.

1991-01-01

Five lead-containing slags and four mattes were analyzed to reveal microstructure, semi-quantitative microchemistry, and phases present. To determine if the slags could be incorporated as a glass so that lead release levels could be stabilized, glass batches were formulated based on slag compositions. Leaching tests showed that all materials that were fritted in a glass batch had lower lead release levels than non-adjusted materials, and all could satisfy EPA test requirements. The mole ratio of glass modifiers to glass formers played an important role in the extent of lead release. Small additions of phosphate to a batch had a significant effect on lowering lead release levels
In-situ Investigation of Lead-free Solder Alloy Formation Using a Hot-plate Microscope

DEFF Research Database (Denmark)

Bergmann, René; Tang, Peter Torben; Hansen, Hans Nørgaard

2007-01-01

This work presents the advantages of using a hot-plate microscope for investigation of new (high-temperature) lead- free solders as in-situ analysis tool and preparation equipment. A description of the equipment and the preparation method is given and some examples are outlined. The formation...
Effects of metallic nanoparticle doped flux on the interfacial intermetallic compounds between lead-free solder ball and copper substrate

International Nuclear Information System (INIS)

Sujan, G.K.; Haseeb, A.S.M.A.; Afifi, A.B.M.

2014-01-01

Lead free solders currently in use are prone to develop thick interfacial intermetallic compound layers with rough morphology which are detrimental to the long term solder joint reliability. A novel method has been developed to control the morphology and growth of intermetallic compound layers between lead-free Sn–3.0Ag–0.5Cu solder ball and copper substrate by doping a water soluble flux with metallic nanoparticles. Four types of metallic nanoparticles (nickel, cobalt, molybdenum and titanium) were used to investigate their effects on the wetting behavior and interfacial microstructural evaluations after reflow. Nanoparticles were dispersed manually with a water soluble flux and the resulting nanoparticle doped flux was placed on copper substrate. Lead-free Sn–3.0Ag–0.5Cu solder balls of diameter 0.45 mm were placed on top of the flux and were reflowed at a peak temperature of 240 °C for 45 s. Angle of contact, wetting area and interfacial microstructure were studied by optical microscopy, field emission scanning electron microscopy and energy-dispersive X-ray spectroscopy. It was observed that the angle of contact increased and wetting area decreased with the addition of cobalt, molybdenum and titanium nanoparticles to flux. On the other hand, wettability improved with the addition of nickel nanoparticles. Cross-sectional micrographs revealed that both nickel and cobalt nanoparticle doping transformed the morphology of Cu 6 Sn 5 from a typical scallop type to a planer one and reduced the intermetallic compound thickness under optimum condition. These effects were suggested to be related to in-situ interfacial alloying at the interface during reflow. The minimum amount of nanoparticles required to produce the planer morphology was found to be 0.1 wt.% for both nickel and cobalt. Molybdenum and titanium nanoparticles neither appear to undergo alloying during reflow nor have any influence at the solder/substrate interfacial reaction. Thus, doping of flux
Effects of metallic nanoparticle doped flux on the interfacial intermetallic compounds between lead-free solder ball and copper substrate

Energy Technology Data Exchange (ETDEWEB)

Sujan, G.K., E-mail: sgkumer@gmail.com; Haseeb, A.S.M.A., E-mail: haseeb@um.edu.my; Afifi, A.B.M., E-mail: amalina@um.edu.my

2014-11-15

Lead free solders currently in use are prone to develop thick interfacial intermetallic compound layers with rough morphology which are detrimental to the long term solder joint reliability. A novel method has been developed to control the morphology and growth of intermetallic compound layers between lead-free Sn–3.0Ag–0.5Cu solder ball and copper substrate by doping a water soluble flux with metallic nanoparticles. Four types of metallic nanoparticles (nickel, cobalt, molybdenum and titanium) were used to investigate their effects on the wetting behavior and interfacial microstructural evaluations after reflow. Nanoparticles were dispersed manually with a water soluble flux and the resulting nanoparticle doped flux was placed on copper substrate. Lead-free Sn–3.0Ag–0.5Cu solder balls of diameter 0.45 mm were placed on top of the flux and were reflowed at a peak temperature of 240 °C for 45 s. Angle of contact, wetting area and interfacial microstructure were studied by optical microscopy, field emission scanning electron microscopy and energy-dispersive X-ray spectroscopy. It was observed that the angle of contact increased and wetting area decreased with the addition of cobalt, molybdenum and titanium nanoparticles to flux. On the other hand, wettability improved with the addition of nickel nanoparticles. Cross-sectional micrographs revealed that both nickel and cobalt nanoparticle doping transformed the morphology of Cu{sub 6}Sn{sub 5} from a typical scallop type to a planer one and reduced the intermetallic compound thickness under optimum condition. These effects were suggested to be related to in-situ interfacial alloying at the interface during reflow. The minimum amount of nanoparticles required to produce the planer morphology was found to be 0.1 wt.% for both nickel and cobalt. Molybdenum and titanium nanoparticles neither appear to undergo alloying during reflow nor have any influence at the solder/substrate interfacial reaction. Thus, doping
Effects of In and Ni Addition on Microstructure of Sn-58Bi Solder Joint

Science.gov (United States)

Mokhtari, Omid; Nishikawa, Hiroshi

2014-11-01

In this study, the effect of adding 0.5 wt.% and 1 wt.% In and Ni to Sn-58Bi solder on intermetallic compound (IMC) layers at the interface and the microstructure of the solder alloys were investigated during reflow and thermal aging by scanning electron microscopy and electron probe micro-analysis. The results showed that the addition of minor elements was not effective in suppressing the IMC growth during the reflow; however, the addition of 0.5 wt.% In and Ni was effective in suppressing the IMC layer growth during thermal aging. The thickening kinetics of the total IMC layer was analyzed by plotting the mean thickness versus the aging time on log-log coordinates, and the results showed the transition point from grain boundary diffusion control to a volume diffusion control mechanism. The results also showed that the minor addition of In can significantly suppress the coarsening of the Bi phase.
Study of interfacial reactions in Sn-3.5Ag-3.0Bi and Sn-8.0Zn-3.0Bi sandwich structure solder joint with Ni(P)/Cu metallization on Cu substrate

International Nuclear Information System (INIS)

Sun, Peng; Andersson, Cristina; Wei, Xicheng; Cheng, Zhaonian; Shangguan, Dongkai; Liu, Johan

2007-01-01

In this paper, the coupling effect in Sn-3.5Ag-3.0Bi and Sn-8.0Zn-3.0Bi solder joint with sandwich structure by long time reflow soldering was studied. It was found that the interfacial compound at the Cu substrate was binary Cu-Sn compound in Sn-Ag-Bi solder joint and Cu 5 Zn 8 phase in Sn-Zn-Bi solder joint. The thickness of the Cu-Zn compound layer formed at the Cu substrate was greater than or equal to that of Cu-Sn compound layer, although the reflow soldering temperature of Sn-Zn-Bi (240 o C) was lower than that of Sn-Ag-Bi (250 o C). The stable Cu-Zn compound was the absolute preferential phase in the interfacial layer between Sn-Zn-Bi and the Cu substrate. The ternary (Cu, Ni) 6 Sn 5 compound was formed at the Sn-Ag-Bi/Ni(P)-Cu metallization interface, and a complex alloy Sn-Ni-Cu-Zn was formed at the Sn-Zn-Bi/Ni(P)-Cu metallization interface. It was noted that Cu atoms could diffuse from the Cu substrate through the solder matrix to the Ni(P)-Cu metallization within 1 min reflow soldering time for both solder systems, indicating that just 30 s was long enough for Cu to go through 250 μm diffusion length in the Sn-Ag-Bi solder joint at 250 o C. The coupling effect between Ni(P)/Cu metallization and Cu substrate was confirmed as the type of IMCs at Ni(P) layer had been changed from Ni-Sn system to Cu-Sn system apparently by the diffusion effect of Cu atoms. The (Cu, Ni) 6 Sn 5 layer at the Ni(P)/Cu metallization grew significantly and its thickness was even greater than that of the Cu-Sn compound on the opposite side, however the growth of the complex alloy including Sn, Ni, Cu and Zn on the Ni(P)/Cu metallization was suppressed
Bulletin of Materials Science | Indian Academy of Sciences

Indian Academy of Sciences (India)

Home; Journals; Bulletin of Materials Science; Volume 33; Issue 2. Evaluation of borax solid wastes in production of frits suitable for fast single-fired wall tile opaque glass–ceramic glazes. K Pekkan B Karasu. Ceramics and Glasses Volume 33 Issue 2 April 2010 pp 135-144 ...
Aging effects on the microstructure, surface characteristics and wettability of Cu pretinned with Sn-Pb solders

Energy Technology Data Exchange (ETDEWEB)

Linch, Heidi Sue [Univ. of California, Berkeley, CA (United States)

1993-11-01

This study investigates effects of aging in air and argon at 170 C on Cu coupons which were pretinned with 75Sn-25Pb, 8Sn-92Pb, and 5Sn-95Pb solders. Coatings were applied using electroplating or hot dipping techniques. The coating thickness was controlled between 3 to 3μm and the specimens were aged for 0 hours, 2 hours, 24 hours and 2 weeks. Wetting balance tests were used to evaluate the wettability of the test specimens. Microstructural development was evaluated using X-ray diffraction, energy dispersive X-ray and Auger spectroscopy, as well as optical and scanning electron microscopy. The wetting behavior of the test specimens is interpreted with respect to observed microstructural changes and as a function of aging time, solder composition, and processing conditions.
The Effects of Antimony Addition on the Microstructural, Mechanical, and Thermal Properties of Sn-3.0Ag-0.5Cu Solder Alloy

Science.gov (United States)

Sungkhaphaitoon, Phairote; Plookphol, Thawatchai

2018-02-01

In this study, we investigated the effects produced by the addition of antimony (Sb) to Sn-3.0Ag-0.5Cu-based solder alloys. Our focus was the alloys' microstructural, mechanical, and thermal properties. We evaluated the effects by means of scanning electron microscopy (SEM), energy dispersive X-ray spectroscopy (EDX), differential scanning calorimetry (DSC), and a universal testing machine (UTM). The results showed that a part of the Sb was dissolved in the Sn matrix phase, and the remaining one participated in the formation of intermetallic compounds (IMCs) of Ag3(Sn,Sb) and Cu6(Sn,Sb)5. In the alloy containing the highest wt pct Sb, the added component resulted in the formation of SnSb compound and small particle pinning of Ag3(Sn,Sb) along the grain boundary of the IMCs. Our tests of the Sn-3.0Ag-0.5Cu solder alloys' mechanical properties showed that the effects produced by the addition of Sb varied as a function of the wt pct Sb content. The ultimate tensile strength (UTS) increased from 29.21 to a maximum value of 40.44 MPa, but the pct elongation (pct EL) decreased from 48.0 to a minimum 25.43 pct. Principally, the alloys containing Sb had higher UTS and lower pct EL than Sb-free solder alloys due to the strengthening effects of solid solution and second-phase dispersion. Thermal analysis showed that the alloys containing Sb had a slightly higher melting point and that the addition amount ranging from 0.5 to 3.0 wt pct Sb did not significantly change the solidus and liquidus temperatures compared with the Sb-free solder alloys. Thus, the optimal concentration of Sb in the alloys was 3.0 wt pct because the microstructure and the ultimate tensile strength of the SAC305 solder alloys were improved.
Pressure brazing of ceramics to metals with copper solder

International Nuclear Information System (INIS)

Pavlova, M.A.; Metelkin, I.I.

1986-01-01

The effect on the quality of joints brazed with copper of different non metallized aluminooxide dielectrics with metals and alloys of a series of technological parameters (temperature, pressure, holding, and medium) in the course of pressure brazing is investigated. It is shown that in case of brazing with kovar and nickel the character of dependences is identical, however in all cases the joints with nickel are more durable. For the ceramics - molybdenum system characterized by weak interaction with copper solder kinetic dependences have no maximum and only under holding of more than 20 min the constant strength of 150-190 MPa is attained
Non-contact estimation of the bond quality in soldered thin laminate by laser generated lamb waves; Laser reiki ramuha ni yoru handazuke sekisohaku no setsugo seijo no hisesshoku hyoka

Energy Technology Data Exchange (ETDEWEB)

Kasama, H.; Futatsugi, T.; Cho, H.; Takemoto, M. [Aoyama-Gakuin University, Tokyo (Japan). Faculty of Science and Engineering

1998-03-20

The bond quality of a solder-bonded copper laminated plate was modeled into rigid contact (rc) and slip contact (sc) to calculate the velocity dispersion of lamb waves. The velocity dispersion of laser generated lamb waves was measured, and the bond quality or the thickness of a solder layer was evaluated by non-contact. In the model whose bond surface is rc, the velocity dispersion of lamb waves can be calculated under conditions where the stress and displacement in an interface are continuous. In the model whose bond surface is sc, it can be calculated under conditions where an interface slips freely. Weak bond indicates the velocity dispersion between rc and sc. In this model, the velocity dispersion can also be calculated by a change in the thickness of a solder layer and used for quantitative evaluation of a bond interface. A three-layer solder bond manufactured for trial could be evaluated from the velocity dispersion of laser lamb waves. At the room temperature, the change in bond quality near the solder melting point of bond laminate that was judged as rc was investigated. When the solidus temperature is exceeded, the amplitude of lamb waves and the velocity dispersion changed largely. The amplitude of lamb waves increases as the liquid phase ratio increases. The bond quality near the solder melting point can be evaluated using lamb waves. 9 refs., 10 figs., 2 tabs.
Effect of surface oxide on the melting behavior of lead-free solder nanowires and nanorods

International Nuclear Information System (INIS)

Gao Fan; Rajathurai, Karunaharan; Cui, Qingzhou; Zhou, Guangwen; NkengforAcha, Irene; Gu Zhiyong

2012-01-01

Lead-free nanosolders have shown promise in nanowire and nanoelectronics assembly. Among various important parameters, melting is the most fundamental property affecting the assembly process. Here we report that the melting behavior of tin and tin/silver nanowires and nanorods can be significantly affected by the surface oxide of nanosolders. By controlling the nanosolder reflow atmosphere using a flux, the surface oxide of the nanowires/nanorods can be effectively removed and complete nanosolder melting can be achieved. The complete melting of the nanosolders leads to the formation of nanoscale to microscale spherical solder balls, followed by Ostwald ripening phenomenon. The contact angle of the microscale solder balls formed on Si substrate was measured by direct electron microscopic imaging. These results provide new insights into micro- and nanoscale phase transition and liquid droplet coalescence from nanowires/nanorods to spheroids, and are relevant to nanoscale assembly and smaller ball grid array formation.

Current redistribution in cables made of insulated, soldered, or oxidized strands

International Nuclear Information System (INIS)

Turck, B.

1979-07-01

Current redistributions are compared in cables made of insulated strands, soldered, or oxidized strands and insulated strands with periodic joints. After discussing the different current redistributions in the cases of a rapidly changing current and a dc current, several particular situations are investigated: what happens if a strand is broken, or if a local normal zone appears that does not affect all the strands equally, the detection of this normal zone, and the influence of short circuits between strands
Improving the mechanical performance of Sn57.6Bi0.4Ag solder joints on Au/Ni/Cu pads during aging and electromigration through the addition of tungsten (W) nanoparticle reinforcement

Energy Technology Data Exchange (ETDEWEB)

Li, Yi, E-mail: yili64-c@my.cityu.edu.hk [Department of Electronic Engineering, City University of Hong Kong, Tat Chee Avenue, Kowloon Tong (Hong Kong); Luo, Kaiming; Lim, Adeline B.Y.; Chen, Zhong [School of Materials Science and Engineering, Nanyang Technological University, Singapore 639798 (Singapore); Wu, Fengshun [School of Materials Science and Engineering, Huazhong University of Science and Technology, 1037 Luoyu Road, Wuhan (China); Chan, Y.C. [Department of Electronic Engineering, City University of Hong Kong, Tat Chee Avenue, Kowloon Tong (Hong Kong)

2016-07-04

Sn57.6Bi0.4Ag solder has been reinforced successfully through the addition of tungsten (W) nanoparticles at a concentration of 0.5 wt%. With the addition of W nanoparticles, the solder matrix lamellar interphase spacing was reduced by 31.0%. Due to the dispersion of W nanoparticles and the consequently refined microstructure, the mechanical properties of the solder alloy were enhanced, as indicated by a 6.2% improvement in the microhardness. During the reflow of solder on Au/Ni/Cu pads, the entire Au layer dissolved into the molten solder rapidly and a large number of (Au,Ni)(Sn,Bi){sub 4} particles were formed. The fracture path of the as-reflowed joint was within the solder region, showing ductile characteristic, and the shear strength was reinforced by 8.2%, due to the enhanced mechanical properties of the solder. During the subsequent aging process, the Au migrated back towards the interface and a thick layer of interfacial (Au,Ni)(Sn,Bi){sub 4} IMC was formed, leading to the shift of the fracture path to the interfacial IMC region, the transformation to brittle fracture and the deterioration of the strength of the joint, due to Au embrittlement. By adding W nanoparticles, the migration of Au was mitigated and the thickness of the (Au,Ni)(Sn,Bi){sub 4} layer was reduced significantly, which reduced the Au embrittlement-induced deterioration of the strength of the joint. During electromigration, the segregation of the Bi-rich and Sn-rich phases and the accumulation of the (Au,Ni)(Sn,Bi){sub 4} layer at cathode interface were mitigated by the addition of W nanoparticles, which improved the electromigration resistance.
Size effects in tin-based lead-free solder joints: Kinetics of bond formation and mechanical characteristics

Science.gov (United States)

Abdelhadi, Ousama Mohamed Omer

Continuous miniaturization of microelectronic interconnects demands smaller joints with comparable microstructural and structural sizes. As the size of joints become smaller, the volume of intermetallics (IMCs) becomes comparable with the joint size. As a result, the kinetics of bond formation changes and the types and thicknesses of IMC phases that form within the constrained region of the bond varies. This dissertation focuses on investigating combination effects of process parameters and size on kinetics of bond formation, resulting microstructure and the mechanical properties of joints that are formed under structurally constrained conditions. An experiment is designed where several process parameters such as time of bonding, temperature, and pressure, and bond thickness as structural chracteristic, are varied at multiple levels. The experiment is then implemented on the process. Scanning electron microscope (SEM) is then utilized to determine the bond thickness, IMC phases and their thicknesses, and morphology of the bonds. Electron backscatter diffraction (EBSD) is used to determine the grain size in different regions, including the bulk solder, and different IMC phases. Physics-based analytical models have been developed for growth kinetics of IMC compounds and are verified using the experimental results. Nanoindentation is used to determine the mechanical behavior of IMC phases in joints in different scales. Four-point bending notched multilayer specimen and four-point bending technique were used to determine fracture toughness of the bonds containing IMCs. Analytical modeling of peeling and shear stresses and fracture toughness in tri-layer four-point bend specimen containing intermetallic layer was developed and was verified and validated using finite element simulation and experimental results. The experiment is used in conjunction with the model to calculate and verify the fracture toughness of Cu6Sn5 IMC materials. As expected two different IMC phases
Thermal fatigue life evaluation of SnAgCu solder joints in a multi-chip power module

Science.gov (United States)

Barbagallo, C.; Malgioglio, G. L.; Petrone, G.; Cammarata, G.

2017-05-01

For power devices, the reliability of thermal fatigue induced by thermal cycling has been prioritized as an important concern. The main target of this work is to apply a numerical procedure to assess the fatigue life for lead-free solder joints, that represent, in general, the weakest part of the electronic modules. Starting from a real multi-chip power module, FE-based models were built-up by considering different conditions in model implementation in order to simulate, from one hand, the worst working condition for the module and, from another one, the module standing into a climatic test room performing thermal cycles. Simulations were carried-out both in steady and transient conditions in order to estimate the module thermal maps, the stress-strain distributions, the effective plastic strain distributions and finally to assess the number of cycles to failure of the constitutive solder layers.
Thermal fatigue life evaluation of SnAgCu solder joints in a multi-chip power module

International Nuclear Information System (INIS)

Barbagallo, C; Petrone, G; Cammarata, G; Malgioglio, G L

2017-01-01

For power devices, the reliability of thermal fatigue induced by thermal cycling has been prioritized as an important concern. The main target of this work is to apply a numerical procedure to assess the fatigue life for lead-free solder joints, that represent, in general, the weakest part of the electronic modules. Starting from a real multi-chip power module, FE-based models were built-up by considering different conditions in model implementation in order to simulate, from one hand, the worst working condition for the module and, from another one, the module standing into a climatic test room performing thermal cycles. Simulations were carried-out both in steady and transient conditions in order to estimate the module thermal maps, the stress-strain distributions, the effective plastic strain distributions and finally to assess the number of cycles to failure of the constitutive solder layers. (paper)
Influence of Poly(ethylene glycol) Degradation on Voiding Sporadically Occurring in Solder Joints with Electroplated Cu

Science.gov (United States)

Wafula, F.; Yin, L.; Borgesen, P.; Andala, D.; Dimitrov, N.

2012-07-01

This paper presents a comprehensive study of the effect of poly(ethylene glycol) (PEG) degradation on the void formation known to take place sporadically at the interface between electroplated Cu and Pb-free solder. Thorough chemical analysis of our plating solution, carried out at different times of the deposition process by matrix-assisted laser desorption ionization time-of-flight mass spectroscopy, reveals a dramatic shift in the peaks to lower mass range with time. Scanning electron microscopy cross-sectional images of solder joints with Cu samples that have been plated at different times in the course of solution aging show a decrease in void formation. A decreasing magnitude of the deposition overpotential also seen during aging suggests that, breaking down to lower-molecular-weight fragments, PEG loses its suppression effect and likely has lower impact on the voiding propensity. This indirect correlation is confirmed further by the use of plating solutions containing PEG with preselected molecular weight. We also report on the effect of the surface area-to-solution volume ratio on PEG degradation studied by comparative experiments performed in a 50-mL bath with a rotating disc electrode and in a larger cell (Hull cell) with volume of 267 mL. The results show that, at fixed charge per unit volume, PEG degrades at a greatly accelerated rate in the Hull cell featuring higher electrode surface-to-solution volume ratio. Analysis of solder joints with accordingly grown Cu layers suggests that the voiding decreases faster with the accelerated rate of PEG degradation.
High temperature soldering of graphite

International Nuclear Information System (INIS)

Anikin, L.T.; Kravetskij, G.A.; Dergunova, V.S.

1977-01-01

The effect is studied of the brazing temperature on the strength of the brazed joint of graphite materials. In one case, iron and nickel are used as solder, and in another, molybdenum. The contact heating of the iron and nickel with the graphite has been studied in the temperature range of 1400-2400 ged C, and molybdenum, 2200-2600 deg C. The quality of the joints has been judged by the tensile strength at temperatures of 2500-2800 deg C and by the microstructure. An investigation into the kinetics of carbon dissolution in molten iron has shown that the failure of the graphite in contact with the iron melt is due to the incorporation of iron atoms in the interbase planes. The strength of a joint formed with the participation of the vapour-gas phase is 2.5 times higher than that of a joint obtained by graphite recrystallization through the carbon-containing metal melt. The critical temperatures are determined of graphite brazing with nickel, iron, and molybdenum interlayers, which sharply increase the strength of the brazed joint as a result of the formation of a vapour-gas phase and deposition of fine-crystal carbon
Studies on upgrading quality of zircon concentrate to meet the standard for frit by a combination of using a screen plate electrostatic separator and other beneficiation methods

International Nuclear Information System (INIS)

Nguyen Duc Hung

2003-01-01

In the present work, researches on qualitative upgrade of zircon concentrate in order to meet the standard for frit were carried out by combinations of a screen plate type electrostatic separator with other physical beneficiation methods such as magnetic separation, flotation, gravity by air-table along with chemical treatment on laboratory scale was itself manufactured for studied scopes, after that zircon concentrate about 63.9-64.8% of ZrO 2 , less than 0.13% of TiO 2 and 0.128% of Fe 2 O 3 values were recovered. (NDH)
Thermal Analysis of the Sn-Ag-Cu-In Solder Alloy

DEFF Research Database (Denmark)

Sopousek, J.; Palcut, Marián; Hodúlová, Erika

2010-01-01

The tin-based alloy Sn-1.5Ag-0.7Cu-9.5In (composition in wt.%) is a potential candidate for lead-free soldering at temperatures close to 200°C due to the significant amount of indium. Samples of Sn-1.5Ag-0.7Cu-9.5In were prepared by controlled melting of the pure elements, followed by quenching...... to room temperature. The samples were analyzed by scanning electron microscopy/energy-dispersive x-ray spectroscopy (SEM/EDS) and electron backscatter diffraction. The solidified melt consisted of four different phases. Solidification behavior was monitored by heat-flux differential scanning calorimetry...
Selective masking and demasking for the stepwise complexometric determination of aluminium, lead and zinc from the same solution

OpenAIRE

Kayal, Nijhuma; Singh, Nahar

2008-01-01

Abstract Background A complexometric method based on selective masking and de-masking has been developed for the rapid determination of aluminium, lead and zinc from the same solution in glass and glass frit samples. The determination is carried out using potassium cyanide to mask zinc, and excess disodium salt of EDTA to mask lead and aluminium. The excess EDTA was titrated with standard Mn(II)SO4 solution using Erichrome Black-T as the indicator. Subsequently selective de-masking agents – t...
Hanford Waste Vitrification Program process development: Melt testing subtask, pilot-scale ceramic melter experiment, run summary

International Nuclear Information System (INIS)

Nakaoka, R.K.; Bates, S.O.; Elmore, M.R.; Goles, R.W.; Perez, J.M.; Scott, P.A.; Westsik, J.H.

1996-03-01

Hanford Waste Vitrification Program (HWVP) activities for FY 1985 have included engineering and pilot-scale melter experiments HWVP-11/HBCM-85-1 and HWVP-12/PSCM-22. Major objectives designated by HWVP fo these tests were to evaluate the processing characteristics of the current HWVP melter feed during actual melter operation and establish the product quality of HW-39 borosilicate glass. The current melter feed, defined during FY 85, consists of reference feed (HWVP-RF) and glass-forming chemicals added as frit
Aging effects on fracture behavior of 63Sn37Pb eutectic solder during tensile tests under the SEM

International Nuclear Information System (INIS)

Ding Ying; Wang Chunqing; Li Mingyu; Bang Hansur

2004-01-01

This study investigates the influence of aging treatment on fracture behavior of Sn-Pb eutectic solder alloys at different loading rate regime during tensile tests under the scanning electron microscope. In high homologous temperature, the solder exhibit the creep behavior that could be confirmed through the phenomena of grain boundary sliding (GBS) to both as-cast and aged specimens. Owing to the large grain scale after high temperature storage, boundary behavior was limited to some extent for the difficulty in grain rotation and boundary migration. Instead, drastic intragranular deformation occurred. Also, the phase coarsening weakened the combination between lead-rich phase and tin matrix. Consequently, surface fragmentation was detected for the aged specimens. Furthermore, the fracture mechanism changed from intergranular dominated to transgranular dominated with increasing loading rate to both specimens during early stage
Recycle Glass in Foam Glass Production

DEFF Research Database (Denmark)

Petersen, Rasmus Rosenlund; König, Jakob; Yue, Yuanzheng

The foam glass industry turn recycle glass into heat insulating building materials. The foaming process is relative insensitive to impurities in the recycle glass. It is therefore considered to play an important role in future glass recycling. We show and discuss trends of use of recycled glasses...... in foam glass industry and the supply sources and capacity of recycle glass....
Improved Switching Characteristics of Fast Power MOSFETs Applying Solder Bump Technology

Directory of Open Access Journals (Sweden)

Sibylle Dieckerhoff

2008-01-01

Full Text Available The impact of a reduced package stray inductance on the switching performance of fast power MOSFETs is discussed applying advanced 3D packaging technologies. Starting from an overview over new packaging approaches, a solder bump technology using a flexible PI substrate is exemplarily chosen for the evaluation. Measurement techniques to determine the stray inductance are discussed and compared with a numerical solution based on the PEEC method. Experimental results show the improvement of the voltage utilization while there is only a slight impact on total switching losses.
Damage Model for Reliability Assessment of Solder Joints in Wind Turbines

DEFF Research Database (Denmark)

Kostandyan, Erik; Sørensen, John Dalsgaard

2012-01-01

environmental factors. Reliability assessment for such type of products conventionally is performed by classical reliability techniques based on test data. Usually conventional reliability approaches are time and resource consuming activities. Thus in this paper we choose a physics of failure approach to define...... damage model by Miner’s rule. Our attention is focused on crack propagation in solder joints of electrical components due to the temperature loadings. Based on the proposed method it is described how to find the damage level for a given temperature loading profile. The proposed method is discussed...
Microstructural and mechanical characterization of melt spun process Sn-3.5Ag and Sn-3.5Ag-xCu lead-free solders for low cost electronic assembly

Energy Technology Data Exchange (ETDEWEB)

Mostafa Shalaby, Rizk; Kamal, Mustafa [Metal Physics Laboratory, Physics Department, Faculty of Science, Mansoura University, P.O.Box: 35516, Mansoura (Egypt); Ali, Esmail A.M. [Basic Science Department, Faculty of Engineering, University of Science & Technology (Yemen); Gumaan, Mohammed S., E-mail: m.gumaan1@gmail.com [Metal Physics Laboratory, Physics Department, Faculty of Science, Mansoura University, P.O.Box: 35516, Mansoura (Egypt); Basic Science Department, Faculty of Engineering, University of Science & Technology (Yemen)

2017-04-06

This paper aims to investigate the reliability of mechanical and creep behavior for the eutectic Sn-Ag and Sn-Ag-Cu Solder joints rapidly solidified after hot compressing (HC) in terms of structural changes and its relationship with thermal behavior, which has been discussed and compared with their properties before HC process by Mustafa et al. (2016) . These solder joints were prepared by melt-spinning technique and tested by HC at 30 MPa pressure and 150 °C for 90 min, their structural, mechanical and thermal properties after HC process have been investigated by X-ray diffraction (XRD), dynamic resonance techniques (DRT) and differential scanning calorimetry (DSC) techniques respectively and compared with these solders before HC. The results revealed that the pressure caused some fractures on the solders morphology surfaces. But some benefits for these solders have been occurred, like eliminating the internal stresses through recrystallization process whose evidence by the particle size increases after they HC, stabilized structure after HC was due to the metastable phases rearrangements, new intermetallic compounds (IMCs) formation, decreasing, melting temperature range (∆T), lattice strains (ƹ) and entropy change (S). These sequential benefits are considered to be the main reasons which lead to decreasing energy loss (Q{sup −1}), creep rate (É›) and thermal stability enhancement. Elastic modulus increment might be due to low elastic lattice distortions after HC, while the stress exponent (n) reduction refers to viscous glide mechanism of deformation after HC instead of climb deformation mechanism before HC.
Miniaturization of Micro-Solder Bumps and Effect of IMC on Stress Distribution

Science.gov (United States)

Choudhury, Soud Farhan; Ladani, Leila

2016-07-01

As the joints become smaller in more advanced packages and devices, intermetallic (IMCs) volume ratio increases, which significantly impacts the overall mechanical behavior of joints. The existence of only a few grains of Sn (Tin) and IMC materials results in anisotropic elastic and plastic behavior which is not detectable using conventional finite element (FE) simulation with average properties for polycrystalline material. In this study, crystal plasticity finite element (CPFE) simulation is used to model the whole joint including copper, Sn solder and Cu6Sn5 IMC material. Experimental lap-shear test results for solder joints from the literature were used to validate the models. A comparative analysis between traditional FE, CPFE and experiments was conducted. The CPFE model was able to correlate the experiments more closely compared to traditional FE analysis because of its ability to capture micro-mechanical anisotropic behavior. Further analysis was conducted to evaluate the effect of IMC thickness on stress distribution in micro-bumps using a systematic numerical experiment with IMC thickness ranging from 0% to 80%. The analysis was conducted on micro-bumps with single crystal Sn and bicrystal Sn. The overall stress distribution and shear deformation changes as the IMC thickness increases. The model with higher IMC thickness shows a stiffer shear response, and provides a higher shear yield strength.
Defense Waste Processing Facility (DWPF) Viscosity Model: Revisions for Processing High TiO₂ Containing Glasses

Energy Technology Data Exchange (ETDEWEB)

Jantzen, C. M. [Savannah River Site (SRS), Aiken, SC (United States). Savannah River National Lab. (SRNL); Edwards, T. B. [Savannah River Site (SRS), Aiken, SC (United States). Savannah River National Lab. (SRNL)

2016-08-30

Radioactive high-level waste (HLW) at the Savannah River Site (SRS) has successfully been vitrified into borosilicate glass in the Defense Waste Processing Facility (DWPF) since 1996. Vitrification requires stringent product/process (P/P) constraints since the glass cannot be reworked once it is poured into ten foot tall by two foot diameter canisters. A unique “feed forward” statistical process control (SPC) was developed for this control rather than statistical quality control (SQC). In SPC, the feed composition to the DWPF melter is controlled prior to vitrification. In SQC, the glass product would be sampled after it is vitrified. Individual glass property-composition models form the basis for the “feed forward” SPC. The models transform constraints on the melt and glass properties into constraints on the feed composition going to the melter in order to guarantee, at the 95% confidence level, that the feed will be processable and that the durability of the resulting waste form will be acceptable to a geologic repository. The DWPF SPC system is known as the Product Composition Control System (PCCS). The DWPF will soon be receiving wastes from the Salt Waste Processing Facility (SWPF) containing increased concentrations of TiO₂, Na₂O, and Cs₂O . The SWPF is being built to pretreat the high-curie fraction of the salt waste to be removed from the HLW tanks in the F- and H-Area Tank Farms at the SRS. In order to process TiO₂ concentrations >2.0 wt% in the DWPF, new viscosity data were developed over the range of 1.90 to 6.09 wt% TiO₂ and evaluated against the 2005 viscosity model. An alternate viscosity model is also derived for potential future use, should the DWPF ever need to process other titanate-containing ion exchange materials. The ultimate limit on the amount of TiO₂ that can be accommodated from SWPF will be determined by the three PCCS models, the waste composition of a given sludge
Soldering Technology (6th) Proceedings of Annual Seminar, 17-18 February 1982.

Science.gov (United States)

1982-02-01

aspect oF health and safety during this presentation. We are hoping that the work conducted by Van 2 Der Molen in the USA will clarify this issue. FLUX... Der Molen , PROC. OF 5th ANNUAL SEMINAR SOLDERING TECHNOLOGY, Naval Weapons Centre, China Lake, California, February 1981. 3. Burge, Perks, O’Brien...developed a new and innovative solution, which we believe to be a significant advance in the state of the art. In this new design (Fig.l) a FM DER
Influence of aging treatment on deformation behavior of 96.5Sn3.5Ag lead-free solder alloy during in situ tensile tests

International Nuclear Information System (INIS)

Ding, Ying; Wang, Chunqing; Tian, Yanhong; Li, Mingyu

2007-01-01

This study investigates the influence of aging treatment on deformation behavior of 96.5Sn3.5Ag eutectic solder alloys with lower strain rate ( -3 s -1 ) during tensile tests under the scanning electron microscope. Results showed that because of the existence of Ag 3 Sn intermetallic particles and the special microstructure of β-Sn phases in Sn3.5Ag solder, grain boundary sliding was not the dominant mechanism any longer for this Pb-free solder. While the interaction of dislocations with the relatively rigid Ag 3 Sn particles began to dominate. For the as-cast specimen, accompanied by partial intragranular cracks, intergranular fracture along the grain boundaries in Sn-Ag eutectic structure or the interphase boundaries between Sn-rich dendrites and Sn-Ag eutectic phases occurred primarily in early tensile stage. However, the boundary behavior was limited by the large Ag 3 Sn particles presented along the Sn-rich dendrites boundaries after aging. Plastic flow was observed in large area, and cracks propagated in a transgranular manner across the Sn-dendrites and Sn-Ag eutectic structure

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