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Sample records for plaster solder index

  1. Objective assessment of plaster cast quality in pediatric distal forearm fractures: Is there an optimal index?

    Science.gov (United States)

    Labronici, Pedro José; Ferreira, Leonardo Termis; Dos Santos Filho, Fernando Claudino; Pires, Robinson Esteves Santos; Gomes, Davi Coutinho Fonseca Fernandes; da Silva, Luiz Henrique Penteado; Gameiro, Vinicius Schott

    2017-02-01

    Several so-called casting indices are available for objective evaluation of plaster cast quality. The present study sought to investigate four of these indices (gap index, padding index, Canterbury index, and three-point index) as compared to a reference standard (cast index) for evaluation of plaster cast quality after closed reduction of pediatric displaced distal forearm fractures. Forty-three radiographs from patients with displaced distal forearm fractures requiring manipulation were reviewed. Accuracy, sensitivity, specificity, false-positive probability, false-negative probability, positive predictive value, negative predictive value, positive likelihood ratio, and negative likelihood ratio were calculated for each of the tested indices. Comparison among indices revealed diagnostic agreement in only 4.7% of cases. The strongest correlation with the cast index was found for the gap index, with a Spearman correlation coefficient of 0.94. The gap index also displayed the best agreement with the cast index, with both indices yielding the same result in 79.1% of assessments. When seeking to assess plaster cast quality, the cast index and gap index should be calculated; if both indices agree, a decision on quality can be made. If the cast and gap indices disagree, the padding index can be calculated as a tiebreaker, and the decision based on the most frequent of the three results. Calculation of the three-point index and Canterbury index appears unnecessary. Copyright © 2016 Elsevier Ltd. All rights reserved.

  2. Index of Complexity, Outcome and Need scored on plaster and digital models.

    NARCIS (Netherlands)

    Veenema, A.C.; Katsaros, C.; Boxum, S.C.; Bronkhorst, E.M.; Kuijpers-Jagtman, A.M.

    2009-01-01

    The aim of this study was to compare standard plaster models with their digital counterparts for the applicability of the Index of Complexity, Outcome, and Need (ICON). Generated study models of 30 randomly selected patients: 30 pre- (T(0)) and 30 post- (T(1)) treatment. Two examiners, calibrated in

  3. Index of Complexity, Outcome and Need scored on plaster and digital models

    NARCIS (Netherlands)

    Veenema, A. C.; Katsaros, C.; Boxum, S. C.; Bronkhorst, E. M.; Kuijpers-Jagtman, A. M.

    2009-01-01

    The aim of this study was to compare standard plaster models with their digital counterparts for the applicability of the Index of Complexity, Outcome, and Need (ICON). Generated study models of 30 randomly selected patients: 30 pre- (T-0) and 30 post- (T-1) treatment. Two examiners, calibrated in t

  4. Adhesive plasters

    Science.gov (United States)

    Holcombe, Jr., Cressie E.; Swain, Ronald L.; Banker, John G.; Edwards, Charlene C.

    1978-01-01

    Adhesive plaster compositions are provided by treating particles of Y.sub.2 O.sub.3, Eu.sub.2 O.sub.3, Gd.sub.2 O.sub.3 or Nd.sub.2 O.sub.3 with dilute acid solutions. The resulting compositions have been found to spontaneously harden into rigid reticulated masses resembling plaster of Paris. Upon heating, the hardened material is decomposed into the oxide, yet retains the reticulated rigid structure.

  5. 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.

  6. Wave soldering with Pb-free solders

    Energy Technology Data Exchange (ETDEWEB)

    Artaki, I.; Finley, D.W.; Jackson, A.M.; Ray, U. [AT and T Bell Labs., Princeton, NJ (United States); Vianco, P.T. [Sandia National Labs., Albuquerque, NM (United States)

    1995-07-01

    The manufacturing feasibility and attachment reliability of a series of newly developed lead-free solders were investigated for wave soldering applications. Some of the key assembly aspects addressed included: wettability as a function of board surface finish, flux activation and surface tension of the molten solder, solder joint fillet quality and optimization of soldering thermal profiles. Generally, all new solder formulations exhibited adequate wave soldering performance and can be considered as possible alternatives to eutectic SnPb for wave soldering applications. Further process optimization and flux development is necessary to achieve the defect levels associated with the conventional SnPb process.

  7. Plaster core washout tool

    Science.gov (United States)

    Heisman, R. M.; Keir, A. R.; Teramura, K.

    1977-01-01

    Tool powered by pressurized water or air removes water soluble plaster lining from Kevlar/epoxy duct. Rotating plastic cutterhead with sealed end fitting connects flexible shaft that allows tool to be used with curved ducts.

  8. 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

  9. Plaster-Wrap Dragons

    Science.gov (United States)

    Vance, Shelly

    2012-01-01

    In this article, the author describes how her students constructed a three-dimensional sculpture of a dragon using plaster wrap and other materials. The dragons were formed from modest means--using only a toilet-paper tube, newsprint, tape and wire.

  10. Plaster-Wrap Dragons

    Science.gov (United States)

    Vance, Shelly

    2012-01-01

    In this article, the author describes how her students constructed a three-dimensional sculpture of a dragon using plaster wrap and other materials. The dragons were formed from modest means--using only a toilet-paper tube, newsprint, tape and wire.

  11. Plaster, Portraits and Pots.

    Science.gov (United States)

    Schimsky, Marc

    1982-01-01

    Describes an art activity in which junior high school students make portrait pots using plaster casts and clay. Each student created a reflection of his or her personality in clay. Specific teaching methods and ways of working with materials are discussed. (AM)

  12. [PHYSICAL PROPERTIES OF PLASTER BANDAGES].

    Science.gov (United States)

    Antabak, Anko; Barisić, Branimir; Andabak, Matej; Bradić, Lucija; Brajcinović, Melita; Haramina, Tatjana; Haluzan, Damir; Fuchs, Nino; Durkovir, Selena; Curković, Selena; Luetić, Tomislav; Sisko, Jerko; Prlić, Ivica

    2015-01-01

    The physical properties of plaster bandages are a very important factor in achieving the basic functions of immobilization (maintaining bone fragments in the best possible position), which directly affects the speed and quality of fracture healing. This paper compares the differences between the physical properties of plaster bandages (mass, specific weight, drying rate, elasticity and strength) and records the differences in plaster modeling of fast bonding 10 cm wide plaster bandages, from three different manufacturers: Safix plus (Hartmann, Germany), Cellona (Lohman Rauscher, Austria) and Gipsan (Ivo Lola Ribar ltd., Croatia). Plaster tiles from ten layers of plaster, dimension 10 x 10 cm were made. The total number of tiles from each manufacturer was 48. The water temperature of 22 °C was used for the first 24 tiles and 34 'C was used for the remainder. The average specific weight of the original packaging was: Cellona (0.52 g/cm3), Gipsan (0.50 g/cm3), Safix plus (0.38 g/cm3). Three days after plaster tile modeling an average specific weight of the tiles was: Gipsan (1.15 g/cm3), Safix plus (1.00 g/cm3), Cellona (1.10 g/cm3). The average humidity of 50% for Safix plus and Cellona plaster tiles was recorded 18 hours after modeling, while for the Gipsan plaster tiles, this humidity value was seen after 48 hours. On the third day after plaster modeling the average humidity of the plaster tiles was 30% for Gipsan, 24% for Safix and 16% for Cellona. Cellona plaster tiles made with 34 °C water achieved the highest elasticity (11.75±3.18 MPa), and Gipsan plaster tiles made with 22 °C had the lowest (7.21±0.9 MPa). Cellona plaster tiles made with 34 °C water showed maximum material strength (4390±838 MPa), and Gipsan plaster tiles made with 22 °C water showed the lowest material strength (771±367 MPa). The rigidity and strength of Cellona and Gipsan plaster are higher in tiles made in warmer water, and for Safix plus are higher in tiles made in cooler water

  13. Moisture transport in coated plaster

    NARCIS (Netherlands)

    Goossens, E.L.J.; Van der Spoel, W.H.; Bancken, E.L.J.

    2001-01-01

    In the framework of the research project: 'Water balance of water-borne paint systems on plaster substrates in relation to fungal growth', a study is carried out to moisture transport mechanisms in coated gypsum plaster. In this contribution, the set-up of the study is described. Besides a descripti

  14. Moisture transport in coated plaster

    NARCIS (Netherlands)

    Goossens, E.L.J.; Van der Spoel, W.H.; Bancken, E.L.J.

    2001-01-01

    In the framework of the research project: 'Water balance of water-borne paint systems on plaster substrates in relation to fungal growth', a study is carried out to moisture transport mechanisms in coated gypsum plaster. In this contribution, the set-up of the study is described. Besides a descripti

  15. [The antalgic and antiphiogistic function and mechanism of RGDT plaster].

    Science.gov (United States)

    Liu, Xiao-Xia; Wang, Zhi-wang; Chien, Xiao-pin; Liu, Cai-min; Tuo, Hai-yan

    2015-09-01

    To study the antalgic and antiphlogistic functions and mechanism of ronggudingtong (RGDT) plaster (traditional Chinese medicine). The painful models were established with hot plate test or acetic acid writhing and the inflammatory models were established with daubing dimethylbenzene on auricle or injecting formaldehyde in toe or synovial envelope to study the antalgic and antiphlogistic functions of RGDT Plaster. The total protein and leukotriene B4(LTB4) in inflammatory exudate were detected to investigate the antalgic and antiphlogistic mechanism of RGDT plaster. The mice were randomly divided into different groups (n = 11), on the basis of drug using, the indexes of pain threshold, swelling degree were observed. Sixty-six mice were used to establish gasbag synovitis model and randomly divided into normal control group,model control group, positive control group (Voltaren gel 0.8 mg/d)and low/medium/high dosage RGDT plaster treating groups(30 mg/d, 60 mg/d, 120 mg/d). 30 mg/d, 60 mg/d,120 mg/d RGDT plaster could upgrade the pain thresholds, remit auricular and foot swelling (P plaster has some antalgic and antiphlogistic functions, and one of the mechanisms is depressing synthesis of LTB4.

  16. Solderability test system

    Energy Technology Data Exchange (ETDEWEB)

    Yost, Fred (Cedar Crest, NM); Hosking, Floyd M. (Albuquerque, NM); Jellison, James L. (Albuquerque, NM); Short, Bruce (Beverly, MA); Giversen, Terri (Beverly, MA); Reed, Jimmy R. (Austin, TX)

    1998-01-01

    A new test method to quantify capillary flow solderability on a printed wiring board surface finish. The test is based on solder flow from a pad onto narrow strips or lines. A test procedure and video image analysis technique were developed for conducting the test and evaluating the data. Feasibility tests revealed that the wetted distance was sensitive to the ratio of pad radius to line width (l/r), solder volume, and flux predry time.

  17. Solderability test system

    Energy Technology Data Exchange (ETDEWEB)

    Yost, F.; Hosking, F.M.; Jellison, J.L.; Short, B.; Giversen, T.; Reed, J.R.

    1998-10-27

    A new test method to quantify capillary flow solderability on a printed wiring board surface finish. The test is based on solder flow from a pad onto narrow strips or lines. A test procedure and video image analysis technique were developed for conducting the test and evaluating the data. Feasibility tests revealed that the wetted distance was sensitive to the ratio of pad radius to line width (l/r), solder volume, and flux predry time. 11 figs.

  18. Reduced oxide soldering activation (ROSA) PWB solderability testing

    Energy Technology Data Exchange (ETDEWEB)

    Hernandez, C.L.; Hosking, F.M. [Sandia National Labs., Albuquerque, NM (United States). Physical and Joining Metallurgy Dept.; Reed, J. [Texas Instruments, Austin, TX (United States); Tench, D.M.; White, J. [Rockwell Science Center, Thousand Oaks, CA (United States)

    1996-02-01

    The effect of ROSA pretreatment on the solderability of environmentally stressed PWB test coupons was investigated. The PWB surface finish was an electroplated, reflowed solder. Test results demonstrated the ability to recover plated-through-hole fill of steam aged samples with solder after ROSA processing. ROSA offers an alternative method for restoring the solderability of aged PWB surfaces.

  19. [Transdermal behavior of effective constituents in xuanbi gel plaster].

    Science.gov (United States)

    Liu, Yuehuan; Lu, Yang; Du, Shouying; Bai, Jie; Wang, Yue; Li, Huiyun

    2012-05-01

    To study the transdermal absorbability of gentiopicroside, naringin and protosappanin B contained in Xuanbi gel plaster. The Franz diffusing cells method was adopted for the in vitro model of rat belly skins. Three indexes, gentiopicroside, naringin and protosappanin B, residued in the accept liquid, skins and plaster were determined by HPLC. The penetration rates of gentiopicroside, naringin and protosappanin B were respectively 3.47, 1.59, 2.13 microg x cm(-2) x h(-1). After 24 h, their penetration rates were 25.42%, 11.73%, 17.78%, respectively. The residual quantities of gentiopieroside, naringin and protosappanin B in skin were 0.231, 0.593, 0.568 microg x cm(-2), ith the retention rates of 0.027%, 0.227%, 0.475%, respectively. The amount of residue of gentiopicroside, naringin and protosappanin B in plaster were 2179, 674, 278 microg, with the retention rates of 81.36%, 81.92%, 73.83%, respectively. The in vitro transdermal behavior of Xuanbi gel plaster is close to a zero-order process. The residual quantity the retention rate in skins is much lower than the penetration rate and the residual rate in plaster.

  20. Lead-free solder

    Energy Technology Data Exchange (ETDEWEB)

    Anderson, Iver E. (Ames, IA); Terpstra, Robert L. (Ames, IA)

    2001-05-15

    A Sn--Ag--Cu eutectic alloy is modified with one or more low level and low cost alloy additions to enhance high temperature microstructural stability and thermal-mechanical fatigue strength without decreasing solderability. Purposeful fourth or fifth element additions in the collective amount not exceeding about 1 weight % (wt. %) are added to Sn--Ag--Cu eutectic solder alloy based on the ternary eutectic Sn--4.7%Ag--1.7%Cu (wt. %) and are selected from the group consisting essentially of Ni, Fe, and like-acting elements as modifiers of the intermetallic interface between the solder and substrate to improve high temperature solder joint microstructural stability and solder joint thermal-mechanical fatigue strength.

  1. Removing Dross From Molten Solder

    Science.gov (United States)

    Webb, Winston S.

    1990-01-01

    Automatic device helps to assure good solder connections. Machine wipes dross away from area on surface of molten solder in pot. Sweeps across surface of molten solder somewhat in manner of windshield wiper. Each cycle of operation triggered by pulse from external robot. Equipment used wherever precise, automated soldering must be done to military specifications.

  2. Solder dross removal apparatus

    Science.gov (United States)

    Webb, Winston S. (Inventor)

    1992-01-01

    An automatic dross removal apparatus (10) is disclosed for removing dross from the surface of a solder bath (22) in an automated electric component handling system. A rotatable wiper blade (14) is positioned adjacent the solder bath (22) which skims the dross off of the surface prior to the dipping of a robot conveyed component into the bath. An electronic control circuit (34) causes a motor (32) to rotate the wiper arm (14) one full rotational cycle each time a pulse is received from a robot controller (44) as a component approaches the solder bath (22).

  3. Orthodontic measurements on digital study models compared with plaster models: a systematic review.

    Science.gov (United States)

    Fleming, P S; Marinho, V; Johal, A

    2011-02-01

    The aim of this study is to evaluate the validity of the use of digital models to assess tooth size, arch length, irregularity index, arch width and crowding versus measurements generated on hand-held plaster models with digital callipers in patients with and without malocclusion. Studies comparing linear and angular measurements obtained on digital and standard plaster models were identified by searching multiple databases including MEDLINE, LILACS, BBO, ClinicalTrials.gov, the National Research Register and Pro-Quest Dissertation Abstracts and Thesis database, without restrictions relating to publication status or language of publication. Two authors were involved in study selection, quality assessment and the extraction of data. Items from the Quality Assessment of Studies of Diagnostic Accuracy included in Systematic Reviews checklist were used to assess the methodological quality of included studies. No meta-analysis was conducted. Comparisons between measurements of digital and plaster models made directly within studies were reported, and the difference between the (repeated) measurement means for digital and plaster models were considered as estimates. Seventeen relevant studies were included. Where reported, overall, the absolute mean differences between direct and indirect measurements on plaster and digital models were minor and clinically insignificant. Orthodontic measurements with digital models were comparable to those derived from plaster models. The use of digital models as an alternative to conventional measurement on plaster models may be recommended, although the evidence identified in this review is of variable quality. © 2010 John Wiley & Sons A/S.

  4. Low temperature aluminum soldering analysis

    Energy Technology Data Exchange (ETDEWEB)

    Peterkort, W.G.

    1976-09-01

    The investigation of low temperature aluminum soldering included the collection of spread factor and dihedral angle data for several solder alloys and a study of flux effects on aluminum. Selected solders were subjected to environmental tests and evaluated on the basis of tensile strength, joint resistance, visual appearance, and metallurgical analysis. A production line method for determining adequate flux removal was developed.

  5. Plaster of Paris: the orthopaedic surgeon heritage.

    Science.gov (United States)

    Hernigou, Philippe

    2016-08-01

    Plastering is one of the most ancient of the building handicrafts. Plaster is the common name for calcium sulphate hemi hydrate made by heating the mineral gypsum, the common name for sulphate of lime. In the tenth century the Arabs used liquid plaster in orthopaedic treatment. At the beginning of the nineteenth century, patients with fractures of the lower extremities-and often of the upper extremities as well-were treated in bed with restriction of all activity for many weeks until the fractures united. It was the practice of surgeons to dress wounds and fractures at frequent intervals. The bandages, pads, and splints were removed, the fractures manipulated, and the dressings reapplied. The search for simpler, less cumbersome methods of treatment led to the development of occlusive dressings, stiffened at first with starch and later with plaster of Paris. The ambulatory treatment of fractures was the direct result of these innovations. Two military surgeons, Antonius Mathijsen of the Netherlands, and Nikolai Ivanovitch Pirogov of Russia, were responsible for the introduction of the new plaster bandage technique. At the beginning of the twentieth century the technique was improved by Jean-François Calot, a French surgeon, who invented the hand manufacture of plaster bandage as a roll. During the twentieth century, walking cast and ambulation for fresh fractures were developed with plaster and pin incorporated in plaster; the open fracture care concept was introduced with plaster of Paris by Trueta before the external fixation.

  6. Mechanical properties of QFP micro-joints soldered with lead-free solders using diode laser soldering technology

    Institute of Scientific and Technical Information of China (English)

    HAN Zong-jie; XUE Song-bai; WANG Jian-xin; ZHANG Xin; ZHANG Liang; YU Sheng-lin; WANG Hui

    2008-01-01

    Soldering experiments of quad flat package(QFP) devices were carried out by means of diode laser soldering system with Sn-Ag-Cu and Sn-Cu-Ni lead-free solders, and competitive experiments were also carried out not only with Sn-Pb eutectic solders but also with infrared reflow soldering method. The results indicate that under the conditions of laser continuous scanning mode as well as the fixed laser soldering time, an optimal power exists, while the optimal mechanical properties of QFP micro-joints are gained. Mechanical properties of QFP micro-joints soldered with laser soldering system are better than those of QFP micro-joints soldered with IR reflow soldering method. Fracture morphologies of QFP micro-joints soldered with laser soldering system exhibit the characteristic of tough fracture, and homogeneous and fine dimples appear under the optimal laser output power.

  7. The Mechanical Behavior of Sn-Ag4 Solder Joints Subjected to Thermal Cycling

    Institute of Scientific and Technical Information of China (English)

    CHENGuohai; MAJusheng

    2004-01-01

    The method of mount strain gages is used to measure the stress/strain hysteresis loops of the solder joints under thermal cycling. The results show that different solders have different loops; the shape of the loops will change less, and finally become a line along with the thermal cycle increase. The shear module decreases along with the thermal cycling process. But the creep index of the solder joints is not sensitive to the cycling process,which fluctuates between 5 and 7. Because the elements of the solder and matrix materials diffuse during the process, the voids induced in the solder joints expand. The expansion of the voids will lead to the crystal lattice aberrance of solder crystal.

  8. Lethal Necrotizing Fasciitis Triggered by Plaster: Case Report and Review of Literature.

    Science.gov (United States)

    Jain, Mohit J; Mavani, Kinjal

    2016-01-01

    Plasters have been frequently associated with known complications such as infection, and compartment syndrome or deep vein thrombosis. However, life-threatening complication of necrotizing fasciitis (NF) has not been frequently attributed to plaster. We had a case of a 62-year male developing a lethal NF triggered by a below knee plaster for undisplaced fracture medial malleolus after twisting injury. He had no history suggestive of diabetes, renal impairment, and predisposing allergic factors or any comorbidity. Despite early diagnosis and aggressive management with above knee amputation, death occurs due to septic shock on the 20(th) day. A similar case of reported lethal NF triggered by plaster has also been reviewed in this report. This case highlights a life-threatening rare complication of plaster and author recommends thorough clinical history taking, precleaning of limb, use of sterile water and use of adequate wrap around skin for gypsum plasters as prevention apart from high index of suspicion for early diagnosis, and rapid management.

  9. 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 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...... bonds were consistently found to be mechanically stronger than the carbon nanotubes....

  10. Capillary flow solder wettability test

    Energy Technology Data Exchange (ETDEWEB)

    Vianco, P.T.; Rejent, J.A.

    1996-01-01

    A test procedure was developed to assess the capillary flow wettability of solders inside of a confined geometry. The test geometry was comprised of two parallel plates with a controlled gap of constant thickness (0.008 cm, 0.018 cm, 0.025 cm, and 0.038 cm). Capillary flow was assessed by: (1) the meniscus or capillary rise of the solder within the gap, (2) the extent of void formation in the gap, and (3) the time-dependence of the risen solder film. Tests were performed with the lead-free solders.

  11. Plaster: our orthopaedic heritage: AAOS exhibit selection.

    Science.gov (United States)

    DeMaio, Marlene; McHale, Kathleen; Lenhart, Martha; Garland, Joshua; McIlvaine, Christopher; Rhode, Michael

    2012-10-17

    Plaster has been used for centuries as a stiffening agent to treat fractures and other musculoskeletal conditions that require rest, immobilization, or correction of a deformity. Despite modern metallurgy and internal stabilization, plaster casts and splints remain an important means of external stabilization. Casting is a dying art as modern internal and external fixation replace external immobilization. Proper casting technique is paramount. This manuscript outlines the history and chemistry of immobilization materials and techniques as well as the differences among them and the advantages and disadvantages of each. Historical references, peer-reviewed journals, textbooks, and primary sources were reviewed to provide data for this review. The history of immobilization reveals a progressive development and refinement of materials that culminated in Mathijsen's plaster bandage in 1851. In 1798, calcium sulfate (plaster of Paris) was introduced. By 1927, crinoline rolls dipped in plaster treated with binding agents facilitated application. Synthetic casting "tapes" (45% polyurethane resin and 55% fiberglass) were introduced in the 1970s. Splinting techniques are ancient, with development spurred by treatment of war wounds. Plaster relies on soft-tissue contact to maintain rigidity. There are well-known advantages, disadvantages, and complications of plaster management. Casting materials all create an exothermic reaction. Burns are associated with water temperatures of >24°C, more than eight layers (ply), and inadequate ventilation. The maximum water temperature must be lower with fiberglass casts. Plaster was the definitive management for most fractures for over 100 years until it was replaced by modern surgical techniques involving internal fixation in the latter part of the twentieth century. Plaster casts and splints remain an important treatment method for acute and chronic orthopaedic conditions.

  12. Influence of Auricular Plaster Therapy on Sleeping Structure in OSAS Patients

    Institute of Scientific and Technical Information of China (English)

    WANG Xiao-hong; XIAO Lan-ying; WANG Bao-fa; YUAN Ya-dong; PAN Wen-sen; SHI Yu-zhen

    2009-01-01

    To evaluate the therapeutic effects of auricular plaster therapy for obstructive sleep apnea syndrome (OSAS) and the influence on sleeping structure. Methods: 45 OSAS patients were randomly divided into a treatment group of 30 cases and a control group of 15 cases for comparison of the changes in parameters of respiration and sleep at night. Results: The auricular plaster therapy significantly improved the hypoventilation index, respiratory disturbance index and other respiratory parameters as well as the sleeping parameters such as the time and rate of sleep at stage Ⅰ and Ⅱ, and the waking time and rate.Conclusion: Auricular plaster therapy may show good therapeutic effects for OSAS, and with the advantages of low cost and less side effects.

  13. [Application of modified plaster material and device in acupoint plaster therapy].

    Science.gov (United States)

    Liu, Jing-Xing; Wang, Kui; Wang, De-Li; Yang, Zong-Yun

    2013-02-01

    Through the analysis on the methods of medicinal paste preparation, the irritation of skin to medicine and the plaster materials adopted in acupoint plaster therapy for the prevention of winter-attacked disease in summer, the acupoint plaster materials and devices were improved. According to the differences in age, illness condition, acupoint and medicinal irritation of patients, the high-dosage, moderate-dosage and low-dosage series of medicine were prepared in proportion; 2. 5 mL and 5 mL syringes were manually reconstructed as the pushers for the delivery of the medicine paste of different specifications. The new-type materials such as spun-bonded non-woven fabrics, transparent dressing film and spun-laced non-woven skin-color stick plaster were adopted. In the operation, the medicine was classified and prepared more specifically. The dedicated acupoint plaster was characterized as less in skin irritation, breathable in property, convenient in practice and proper in stickiness. The plastic anti-seepage film in the middle and the medicine storage pool for stabilizing medicinal paste could avoid drug leakage. The medicinal paste pusher could achieve the even size, proper thickness and precise dosage of the paste. The new-type plaster material and the self-prepared innovated plaster device contribute to the development of acupoint plaster therapy in clinical application.

  14. Soldering Formalism Theory and Applications

    CERN Document Server

    Wotzasek, C

    1998-01-01

    The soldering mechanism is a new technique to work with distinct manifestations of dualities that incorporates interference effects, leading to new physical results that includes quantum contributions. This approach was used to investigate the cases of electromagnetic dualities, and $D\\geq 2$ bosonization. In the former context this technique is applied for the quantum mechanical harmonic oscillator, the scalar field theory in two dimensions and the Maxwell theory in four dimensions. The soldered actions in any dimension leads to a master action which is duality invariant under a much bigger set of symmetries. The effects of coupling to gravity are also elaborated. In the later context, a technique is developed that solders the dual aspects of some symmetry following from the bosonisation of two distinct fermionic models, leading to new results which cannot be otherwise obtained. Exploiting this technique, the two dimensional chiral determinants with opposite chirality are soldered to reproduce either the usu...

  15. Undercoat Roughness Impact on Venetian Plasters Adhesive Strength

    Directory of Open Access Journals (Sweden)

    Vladimir V. Vakor

    2011-11-01

    Full Text Available The article studies impact of undercoat fractions size on Venetian plasters adhesive strength, describes acrylic and lime plasters adhesive features, offers method for adherence junctions strength evaluation.

  16. Atomic Oxygen Cleaning of Unpainted Plaster Sculptures

    Science.gov (United States)

    Banks, Bruce A.; Miller, Sharon K.

    2017-01-01

    Atomic oxygen erosion of polymers has been found to be a threat to spacecraft in low Earth orbit. As a result ground facilities have been developed to identify coatings to protect polymers such as used for solar array blankets. As a result of extensive laboratory testing, it was discovered that soot and other organic contamination on paintings could be readily removed by atomic oxygen interactions with minimal damage to the artwork. No method, other than dusting, has been found to be effective in the cleaning of unpainted plaster sculptures This presentation discusses the atomic oxygen interaction processes and how effective they are for cleaning soot damaged unpainted plaster sculptures.

  17. 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.

  18. Wetting behavior of alternative solder alloys

    Energy Technology Data Exchange (ETDEWEB)

    Hosking, F.M.; Vianco, P.T.; Hernandez, C.L.; Rejent, J.A.

    1993-07-01

    Recent economic and environmental issues have stimulated interest in solder alloys other than the traditional Sn-Pb eutectic or near eutectic composition. Preliminary evaluations suggest that several of these alloys approach the baseline properties (wetting, mechanical, thermal, and electrical) of the Sn-Pb solders. Final alloy acceptance will require major revisions to existing industrial and military soldering specifications. Bulk alloy and solder joint properties are consequently being investigated to validate their producibility and reliability. The work reported in this paper examines the wetting behavior of several of the more promising commercial alloys on copper substrates. Solder wettability was determined by the meniscometer and wetting balance techniques. The wetting results suggest that several of the alternative solders would satisfy pretinning and surface mount soldering applications. Their use on plated through hole technology might be more difficult since the alloys generally did not spread or flow as well as the 60Sn-40Pb solder.

  19. Asbestos in Plaster and Wall Systems

    Science.gov (United States)

    This collection of letters and clarification on final rules provides guidance on Asbestos National Emissions Standard for Hazardous Air Pollutants for asbestos-containing join compounds, and asbestos-containing materials found in plaster and wall systems.

  20. Plaster People...A La George Segal.

    Science.gov (United States)

    Boulay, Michele

    2003-01-01

    Describes an art project used with eleventh- and twelfth-grade students in which they created plaster self-portraits inspired by the work of George Segal. Includes directions for the casting and lists the art materials needed for the lesson. Explains that the project requires half a semester to complete. (CMK)

  1. Palatal Surface Area of Maxillary Plaster Casts

    DEFF Research Database (Denmark)

    Darvann, Tron Andre; Hermann, Nuno V.; Ersbøll, Bjarne Kjær

    2007-01-01

    Objective: To investigate the relationship between corresponding two-dimensional and three-dimensional measurements on maxillary plaster casts taken from photographs and three-dimensional surface scans, respectively. Materials and Methods: Corresponding two-dimensional and three-dimensional measu......Objective: To investigate the relationship between corresponding two-dimensional and three-dimensional measurements on maxillary plaster casts taken from photographs and three-dimensional surface scans, respectively. Materials and Methods: Corresponding two-dimensional and three......-dimensional measurements of selected linear distances, curve lengths, and (surface) areas were carried out on maxillary plaster casts from individuals with unilateral or bilateral cleft lip and palate. The relationship between two-dimensional and three-dimensional measurements was investigated using linear regression....... Results and Conclusions: Error sources in the measurement of three-dimensional palatal segment surface area from a two-dimensional photograph were identified as photographic distortion (2.7%), interobserver error (3.3%), variability in the orientation of the plaster cast (3.2%), and natural shape...

  2. Inexpensive, removable coating for plaster tooling

    Science.gov (United States)

    Dimino, J. M.; Martin, R. R.

    1970-01-01

    Procedure for thinning and spaying a vinyl material provides strippable film for plaster surfaces. Coating is low-cost, effective seal against moisture and other sources of damage. Coating consists of a mixture of hot-spray vinyl material and 30 to 50 percent by volume of methyl ethyl ketone.

  3. Curative effect of Tai Chi exercise in combination with auricular plaster therapy on improving obesity patient with secondary hyperlipidemia.

    Science.gov (United States)

    Song, Qinghua; Yuan, Yandong; Jiao, Chun; Zhu, Ximei

    2015-01-01

    Observe the effect of Tai Chi in combination with auricular plaster therapy on treating obesity patient with secondary hyperlipidemia. Select 45 patients who suffer from simple obesity and secondary hyperlipidemia and then adopt random digital table to divide them into a Tai Chi group, an auricular plaster therapy group and a combination group. Each group consists of 15 patients. The patients in Tai Chi group are trained with Tai Chi twice a day, while those in auricular plaster therapy are treated with auricular plaster therapy 3-5 times a day and those in the combination group are trained with Tai Chi and auricular plaster therapy twice a day. BMI, body fat percentage and blood lipid indexes are respectively detected for the selected patients in the three groups before treatment and after 180 days' treatment. After 180 days' treatment, BMI index and body fat percentage of Tai Chi group are significantly improved in comparison with those before treatment (Pplaster therapy group are not improved obviously in comparison with those before the treatment (P>0.05) but the blood lipid index is improved significantly (Pplaster therapy can show the obvious synergistic therapeutic effect and thus the combined curative effect is obviously superior to that of the single therapy method.

  4. Solder Joint Health Monitoring Testbed

    Science.gov (United States)

    Delaney, Michael M.; Flynn, James G.; Browder, Mark E.

    2009-01-01

    A method of monitoring the health of selected solder joints, called SJ-BIST, has been developed by Ridgetop Group Inc. under a Small Business Innovative Research (SBIR) contract. The primary goal of this research program is to test and validate this method in a flight environment using realistically seeded faults in selected solder joints. An additional objective is to gather environmental data for future development of physics-based and data-driven prognostics algorithms. A test board is being designed using a Xilinx FPGA. These boards will be tested both in flight and on the ground using a shaker table and an altitude chamber.

  5. 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...

  6. Plaster body wrap: effects on abdominal fat.

    Science.gov (United States)

    Santos Moreira, Juliana; Melo, Ana Sofia Carneiro Pinto de; Noites, Andreia; Couto, Miriam Faria; Melo, Cristina Argel de; Adubeiro, Nuno Carvalho Freire de Almeida

    2013-12-01

    Abdominal fat is associated with metabolic disorders, leading to cardiovascular risk factors and numerous diseases. This study aimed to analyze the effect of plaster body wrap in combination with aerobic exercise on abdominal fat. Nineteen female volunteers were randomly divided into intervention group (IG; n = 10) performing aerobic exercise with plaster body wrap, and control group (CG; n = 9) performing only exercise. Subcutaneous and visceral fat were measured using ultrasound; subcutaneous fat was also estimated on analysis of skinfolds and abdominal perimeters. At the end of the 10-sessions protocol, the IG demonstrated a significant decrease (p ≤ 0.05) in subcutaneous fat at the left anterior superior iliac spine (ASIS) level and in iliac crest perimeter measurements. A large intervention effect size strength (0.80) was found in subcutaneous fat below the navel and a moderate effect size strength on the vertical abdominal skinfold (0.62) and the perimeter of the most prominent abdominal point (0.57). Comparing the initial and final data of each group, the IG showed a significant decrease in numerous variables including visceral and subcutaneous fat above and below the navel measured by ultrasound (p ≤ 0.05). Plaster body wrap in combination with aerobic exercise seems to be effective for abdominal fat reduction.

  7. Dental arch relationships on three-dimensional digital study models and conventional plaster study models for patients with unilateral cleft lip and palate.

    Science.gov (United States)

    Asquith, J A; McIntyre, G T

    2012-09-01

    To determine if three-dimensional (3D) digital study models could replace plaster study models for the evaluation of dental arch relationships for patients with unilateral cleft lip and palate. Observational study involving plaster study models from a records archive. U.K. National Health Service. Thirty sets of study models of 5-year-old patients with unilateral cleft lip and palate were identified and scanned to produce 3D digital study models by ESM Digital Solutions Ltd. (Swords, Co. Dublin, Ireland) using an R250 Orthodontic Study Model Scanner (3Shape A/S, Copenhagen, Denmark). None. The plaster and 3D digital study models were scored using the 5-year-olds' and modified Huddart Bodenham indices and analyzed using the Friedman test (p plaster and 3D digital models. Intra-observer and interobserver reproducibility were good (0.62 to 0.83 and 0.64 to 0.78, respectively). There were no statistically significant differences between the scores for the 3D digital study models when compared to the plaster study models for either the 5-year-olds' index (p  =  .12) or for the modified Huddart Bodenham index (p  =  .506). Three-dimensional digital models are a valid alternative to traditional plaster study models for the evaluation of dental arch relationships in patients with unilateral cleft lip and palate.

  8. The Lead-Free Solder Selection Method and Process Optimization Based on Design of Experiment

    Directory of Open Access Journals (Sweden)

    Wang Bing

    2013-07-01

    Full Text Available In the study, through researching the characteristic of the lead-free solder, we introduce the method of QFD (Quality Function Deployment to transform the demand of production properties and process into the technical demand of the lead-free solder, thus we could transform the demand concept of sampling into a concrete performance index. Finally we can obtain two parameters of the technological competitive power index and market competitive power index to evaluate performance of the lead-free solder through making a series of experiments. We utilize the design of experiment method to find out key parameter of process and the best collocation of parameter, which make the co planarity of tin ball descend to 149 from 178 and promote the process’s ability up to 95.2 from 85%.

  9. 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...

  10. Die Soldering in Aluminium Die Casting

    Energy Technology Data Exchange (ETDEWEB)

    Han, Q.; Kenik, E.A.; Viswanathan, S.

    2000-03-15

    Two types of tests, dipping tests and dip-coating tests were carried out on small steel cylinders using pure aluminum and 380 alloy to investigate the mechanism of die soldering during aluminum die casting. Optical and scanning electron microscopy were used to study the morphology and composition of the phases formed during soldering. A soldering mechanism is postulated based on experimental observations. A soldering critical temperature is postulated at which iron begins to react with aluminum to form an aluminum-rich liquid phase and solid intermetallic compounds. When the temperature at the die surface is higher than this critical temperature, the aluminum-rich phase is liquid and joins the die with the casting during the subsequent solidification. The paper discusses the mechanism of soldering for the case of pure aluminum and 380 alloy casting in a steel mold, the factors that promote soldering, and the strength of the bond formed when soldering occurs. conditions, an aluminum-rich soldering layer may also form over the intermetallic layer. Although a significant amount of research has been conducted on the nature of these intermetallics, little is known about the conditions under which soldering occurs.

  11. Selection of plasters and renders for salt laden masonry substrates

    NARCIS (Netherlands)

    Groot, C.; Hees, R.P.J. van; Wijffels, T.J.

    2009-01-01

    The choice of a repair plaster or render by architects often appears to be the result of fortuitous circumstances, such as prior experience with a plaster or a recommendation by a producer. Seldom is the choice based on a sound assessment of the state of the building and the wall that is to be repai

  12. Sodium chloride crystallization in a "salt transporting" restoration plaster

    NARCIS (Netherlands)

    Lubelli, B.; Hees, R.P.J. van; Groot, C.J.W.P.

    2006-01-01

    In recent years several types of restoration plasters, especially developed for salt loaded substrates, have been introduced on the market. The behaviour of these plasters in the field is, however, not always satisfactory. The reasons for failures may be found both in the moisture and salt transport

  13. Investigation of field temperature in moulds of foamed plaster

    Directory of Open Access Journals (Sweden)

    M. Pawlak

    2007-12-01

    Full Text Available Plaster moulds used in precision foundry are characterized by a very low permeability which, in the case of classic plaster moulds, equals to about 0,01÷0,02 m2/(MPa·s. One of the most effective methods for increasing the permeability is a foaming treatment. Another characteristic feature of plaster is its very good insulating power which has influence on the process of solidification and cooling of a cast and also on a knock-out property. This insulating power is a function of thermophysical properties of plaster which, in turn, depend mainly on the mineralogical composition of the mould material, its bulk density as well as on the temperature of the pouring alloy. In the case of a foamed plaster mould an increase of the degree of foaming increases its porosity which causes a change in its thermophysical properties, thereby increasing susceptibility of the mass to overheating. The susceptibility of the plaster layer surrounding the cast to overheating is favorable because it makes it easier to knock-out of the cast by immersing the hot mould in cold water. Thermal and phase tensions that are created during this process cause fast destruction of plaster. This paper describes our investigations aimed at the determination of the dependence of the mould temperature field on the time of the cast stay in the mould, as recorded in a process of an unsteady heat flow. The determined data were planned to be used for estimation of the technological properties of the plaster mould. The tests were carried out using the plaster α-Supraduro and Alkanol XC (foaming agent. The test mould had a diameter of Ø 120 mm with centrally situated mould cavity of Ø 30 mm. Plaster moulds with a degree of foaming 20; 32,5 and 45% and comparatively from non-foaming plaster were tested and their temperatures were measured at the distance x=2; 9; 21; 25;27; 30 mm from the mould cavity within 25 min. Analysis of the results leads to the conclusion, that the highest

  14. Development of Latent Heat Storage Phase Change Material Containing Plaster

    Directory of Open Access Journals (Sweden)

    Diana BAJARE

    2016-05-01

    Full Text Available This paper reviews the development of latent heat storage Phase Change Material (PCM containing plaster as in passive application. Due to the phase change, these materials can store higher amounts of thermal energy than traditional building materials and can be used to add thermal inertia to lightweight constructions. It was shown that the use of PCMs have advantages stabilizing the room temperature variations during summer days, provided sufficient night ventilation is allowed. Another advantage of PCM usage is stabilized indoor temperature on the heating season. The goal of this study is to develop cement and lime based plaster containing microencapsulated PCM. The plaster is expected to be used for passive indoor applications and enhance the thermal properties of building envelope. The plaster was investigated under Scanning Electron Microscope and the mechanical, physical and thermal properties of created plaster samples were determined.

  15. Development of Latent Heat Storage Phase Change Material Containing Plaster

    Directory of Open Access Journals (Sweden)

    Diana BAJARE

    2016-05-01

    Full Text Available This paper reviews the development of latent heat storage Phase Change Material (PCM containing plaster as in passive application. Due to the phase change, these materials can store higher amounts of thermal energy than traditional building materials and can be used to add thermal inertia to lightweight constructions. It was shown that the use of PCMs have advantages stabilizing the room temperature variations during summer days, provided sufficient night ventilation is allowed. Another advantage of PCM usage is stabilized indoor temperature on the heating season. The goal of this study is to develop cement and lime based plaster containing microencapsulated PCM. The plaster is expected to be used for passive indoor applications and enhance the thermal properties of building envelope. The plaster was investigated under Scanning Electron Microscope and the mechanical, physical and thermal properties of created plaster samples were determined.

  16. Study on laser and hot air reflow soldering of PBGA solder ball

    Institute of Scientific and Technical Information of China (English)

    田艳红; 王春青

    2002-01-01

    Laser and hot air reflow soldering of PBGA solder ball was investigated. Experimental results showed that surface quality and shear strength of solder bump reflowed by laser was superior than the solder bump by hot air, and the microstructure within the solder bump reflowed by laser was much finer. Analysis on interfacial reaction showed that eutectic solder reacted with Au/Ni/Cu pad shortly after the solder was melted. Interface of solder bump reflowed by laser consists of a continuous AuSn4 layer and remnant Au element. Needle-like AuSn4 grew sidewise from interface, and then spread out to the entire interface region. A thin layer of Ni3Sn4 intermetallic compound was found at the interface of solder bump reflowed by hot air, and AuSn4 particles distributed within the whole solder bump randomly. The combination effect of the continuous AuSn4 layer and finer eutectic microstructure contributes to the higher shear strength of solder bump reflowed by laser.

  17. Grindability, Grading and Wettability of Recycled Plaster

    Institute of Scientific and Technical Information of China (English)

    李志新; 彭家惠; 赵海鑫; 邱星星; 赵敏

    2016-01-01

    The changes of grindability, grading and wettability of recycled plaster(R-P)and the mechanisms of these changes were studied by using vickers hardness, particle size distribution(PSD), scanning electron micro-scope(SEM) and nitrogen adsorption porosimetry to reveal that R-P was obviously different from plaster of Paris(POP). At the same milling time, R-P had the characteristics of high specific surface area, fine particle diame-ter and uneven size distribution compared with POP, so R-P possessed both good grindability and poor grading. The water absorption, dissolution rate and mass loss in dry-wet cycle of the hardened recycled gypsum(hardened RG) increased, while the water saturated strength and dry-wet cycle strength decreased significantly compared with the hardened virgin gypsum(hardened VG). Therefore, poor wettability could be seen in R-P. The analyses indi-cated that the changes of grindability and grading could be attributed to the reduction in hardness and the increase in the porosity of hardened RG and that the poor wettability of R-P was caused by the increase of large pores and the changes of microstructure of hardened RG.

  18. WETTABILITY STUDIES OF LEAD-FREE SOLDERS

    African Journals Online (AJOL)

    2012-03-01

    Mar 1, 2012 ... Based on this, a wettability test using copper grid was conducted on the solder alloys produced. The result shows that wetting time varied from 4 seconds to 5 seconds for the lead-free solders ... at the interfaces [4]. This study ...

  19. Nano-soldering to single atomic layer

    Science.gov (United States)

    Girit, Caglar O.; Zettl, Alexander K.

    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.

  20. Moisture and salt transport in three-layer plaster/substrate systems

    NARCIS (Netherlands)

    Petković, J.; Huinink, H.P.; Pel, L.; Kopinga, K.; Hees, R.P.J. van

    2010-01-01

    We have investigated whether a plaster which has two plaster layers with different pore sizes can act as a salt accumulating plaster system, in which salt crystallizes in the base layer of the plaster and not in the substrate or at the external surface. We used two substrates; fired-clay brick and B

  1. Solderable and electroplatable flexible electronic circuit on a porous stretchable elastomer

    Science.gov (United States)

    Jeong, Gi Seok; Baek, Dong-Hyun; Jung, Ha Chul; Song, Ji Hoon; Moon, Jin Hee; Hong, Suck Won; Kim, In Young; Lee, Sang-Hoon

    2012-07-01

    A variety of flexible and stretchable electronics have been reported for use in flexible electronic devices or biomedical applications. The practical and wider application of such flexible electronics has been limited because commercial electronic components are difficult to be directly integrated into flexible stretchable electronics and electroplating is still challenging. Here, we propose a novel method for fabricating flexible and stretchable electronic devices using a porous elastomeric substrate. Pressurized steam was applied to an uncured polydimethylsiloxane layer for the simple and cost-effective production of porous structure. An electroplated nickel anchor had a key role in bonding commercial electronic components on elastomers by soldering techniques, and metals could be stably patterned and electroplated for practical uses. The proposed technology was applied to develop a plaster electrocardiogram dry electrode and multi-channel microelectrodes that could be used as a long-term wearable biosignal monitor and for brain signal monitoring, respectively.

  2. Low cycle fatigue of lead free solder joints

    Energy Technology Data Exchange (ETDEWEB)

    Schemmann, Lars; Wedi, Andre; Baither, Dietmar; Schmitz, Guido [Institut fuer Materialphysik, Westf. Wilhelms-Universitaet, Muenster (Germany)

    2011-07-01

    Presently solders containing lead are banned from consumer electronics. Important alternatives are the Sn-Ag-Cu (SAC) solders and solders containing antimony. This work studies the isothermal low cycle fatigue properties of SAC solders and the SnSb(8) solder. For the experiments, model solder joints were produced and used. They consist of two pure copper plates joined together by a circular disk of solder. Low cycle fatigue experiments were done under displacement control. Furthermore hardness was tested by a micro indenter. In order to find an explanation for the different lifetimes of the solders, several micro structural investigations were performed. For this we used transmission and scanning electron microscopy as well as optical microscopy. The measured data showed a strong relation between lifetime and hardness of the solder alloy. We also found, that the type of solder influences the crack propagation.

  3. Problems with plastered external heat insulation. Probleme mit verputzter Aussenwaermedaemmung

    Energy Technology Data Exchange (ETDEWEB)

    Epple, H.; Foglia, A.; Preisig, H.; Pfefferkorn, J.

    1984-01-01

    Concerning execution, maintenance and service life, walls with plastered external heat insulation constitute an economic method. Owing to experience gained with plastered external heat insulation, it is possible today to provide reliable information on requirements made on ground material and operational execution. The author intends to contribute to a prevention of defects by giving concise examples. A survey on different types of external heat insulation is followed by a treatment of the problem areas of roof-edge connection, base end under ground, modernization of old buildings and cracks in plaster. Principal statements are made concerning steam diffusion, planning, materials and execution.

  4. Dilatometric examination of moulds with plaster binder

    Directory of Open Access Journals (Sweden)

    M. Nadolski

    2011-01-01

    Full Text Available Investigations concerning thermal expansion of moulding materials with plaster binder have been performed for two mixture compositionsof Authors’ own design, as well as for the material used in jewellery industry under the Prima-Cast trade name, and for ThermoMold 1200moulding material. The results of dilatometric examinations of these materials, carried out within the temperature range from about 20°Cto 650°C by means of the DA-3 automatic dilatometer, have been compared. An analysis of this comparison has revealed that it is thematrix composition which is decisive for the magnitude of dimensional changes of moulds, and that applying components which do notexhibit polymorphic transformations reduces dimensional changes of a mould during its thermal treatment.

  5. Thermomechanical Behavior of Monolithic SN-AG-CU Solder and Copper Fiber Reinforced Solders

    Science.gov (United States)

    2005-09-01

    controlled fatigue life, likely because of increased void -nucleation via creep-fatigue interactions. Since the solder is largely under strain-controlled...to plastically deform the solder in order to break the oxide layers and eliminate some minor voids around the NiTi particles. Figure 32... Underfill Constraint Effects during Thermomechanical Cycling of Flip Chip Solder Joints,” Journal of Electronic Materials, Vol. 31, No. 4, 2002

  6. Lead Ingestion Hazard in Hand Soldering Environments.

    Science.gov (United States)

    1984-05-01

    RD-Ai45 663 LEAD INGESTION HAZARD IN HAND SOLDERING ENVIRONMENTS i/i (U) NAVAL WEAPONS CENTER CHINA LAKE CA E R MONSALVE MAY 84 NWC-TP-6545...6545 Lead Ingestion Hazard in Hand Soldering Environments (JD CD I) by Elisabeth R. Monsalve a y- Safety and Security Department I MAY 1984 NAVAL...COVERED LEAD INGESTION HAZARD IN HAND SOLDERING ENVIRONMENTS A summary report 6. PERFORMING ONG. REPORT NUMBER 7. AUTHOR(q) I. CONTRACT O GRANT NUM6ERt

  7. Exothermic properties of plaster-synthetic composite casts.

    Science.gov (United States)

    Burghardt, Rolf D; Anderson, John G; Reed, Rob A; Herzenberg, John E

    2014-03-01

    Plaster casts can cause burns. Synthetic casts do not. Composite plaster-synthetic casts have not been thoroughly evaluated. This study analyzed the temperature from plaster casts compared with composite casts in a variety of in vitro conditions that would simulate clinical practice. A Pyrex cylinder filled with constant body temperature circulating water simulated a human extremity. Circumferential casts, of either plaster or composite construction (plaster inner layer with outer synthetic layer), were applied to the model. Peak temperatures generated by the exothermic reactions were studied relative to the following variables: dip water temperature (24 °C versus 40 °C), cast thickness (16, 30, and 34 ply), and delayed (5-min) versus immediate application of the synthetic outer layers. Peak temperatures from the all-plaster casts were compared with the composite casts of the same thickness. Finally, the relative cast strength was determined. Potentially dangerous high temperatures were measured only when 40 °C dip water was used or when thick (30- or 34-ply) casts were made. Cast strength increased with increasing cast thickness. However, the presence of synthetics in the composite casts layers did not increase cast strength in every case. When applying composite casts, the outer synthetic layers should be applied several minutes after the plaster to minimize temperature rise. Composite casts do not routinely generate peak temperatures higher than plaster casts of similar thickness. Because the skin of children and the elderly is more temperature-sensitive than average adult skin, extra care should be taken to limit the exothermic reaction when casting children and the elderly: clean, room temperature dip water, minimal required cast thickness, avoidance of insulating pillows/blankets while the cast is drying.

  8. [Study of the stability of current plaster substitutes].

    Science.gov (United States)

    Wruhs, O

    1986-06-01

    In connection with company independent test series the clinically required usefulness of four different modern plaster substitutes were examined. A comparison of breakage resistance, deformation and relation of price versus stability of plaster bandages were considered. The advantage of using these materials, especially in case of prolonged cast immobilization, is-despite of higher financial costs - more appropriate because of lower weight, increased durability and hygienical comfort for the patients.

  9. Modeling the diffusion of solid copper into liquid solder alloys

    Energy Technology Data Exchange (ETDEWEB)

    Rizvi, M.J. [School of Computing and Mathematical Sciences, University of Greenwich, 30 Park Row, London, SE10 9LS (United Kingdom)], E-mail: rm77@gre.ac.uk; Lu, H.; Bailey, C. [School of Computing and Mathematical Sciences, University of Greenwich, 30 Park Row, London, SE10 9LS (United Kingdom)

    2009-01-01

    During the soldering process, the copper atoms diffuse into liquid solders. The diffusion process determines integrity and the reworking possibility of a solder joint. In order to capture the diffusion scenarios of solid copper into liquid Sn-Pb and Sn-Cu solders, a computer modeling has been performed for 10 s. An analytical model has also been proposed for calculating the diffusion coefficient of copper into liquid solders. It is found that the diffusion coefficient for Sn-Pb solder is 2.74 x 10{sup -10} m{sup 2}/s and for Sn-Cu solder is 6.44 x 10{sup -9} m{sup 2}/s. The modeling results reveal that the diffusion coefficient is one of the major factors that govern the rate at which solid Cu dissolve in the molten solder. The predicted dissolved amounts of copper into solders have been validated with the help of scanning electron microscopic analysis.

  10. Organic solderability preservation evaluation. Topical report

    Energy Technology Data Exchange (ETDEWEB)

    Becka, G.A.; McHenry, M.R.; Slanina, J.T.

    1997-03-01

    An evaluation was conducted to determine the possible replacement of the hot air solder leveling (HASL) process used in the Allied Signal Federal Manufacturing & Technologies (FM&T) Printed Wiring Board Facility with an organic solderability preservative (OSP). The drivers for replacing HASL include (1) Eliminating lead from PWB fabrication processes; (2) Potential legislation restricting use of lead, (3) Less expensive processing utilizing OSP rather than HASL processing; (4) Avoiding solder dross disposal inherent with HASL processing, (5) OSP provides flat, planar surface required for surface mount technology product, and (6) Trend to thinner PWB designs. A reduction in the cost of nonconformance (CONC) due to HASL defects (exposed copper, solderability, dewetting and non-wetting) would be realized with the incorporation of the OSP process. Several supplier HASL replacement candidates were initially evaluated. One supplier chemistry was chosen for potential use in the FM&T PWB and assembly areas.

  11. Soldering Chiralities; 2, Non-Abelian Case

    CERN Document Server

    Wotzasek, C

    1996-01-01

    We study the non-abelian extension of the soldering process of two chiral WZW models of opposite chiralities, resulting in a (non-chiral) WZW model living in a 2D space-time with non trivial Riemanian curvature.

  12. Shrink-Fit Solderable Inserts Seal Hermetically

    Science.gov (United States)

    Croucher, William C.

    1992-01-01

    Shrink-fit stainless-steel insert in aluminum equipment housing allows electrical connectors to be replaced by soldering, without degrading hermeticity of housing or connector. Welding could destroy electrostatic-sensitive components and harm housing and internal cables. Steel insert avoids problems because connector soldered directly to it rather than welded to housing. Seals between flange and housing, and between connector and flange resistant to leaks, even after mechanical overloading and thermal shocking.

  13. 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.

  14. Temperature versus time curves for manual and automated soldering processes

    Energy Technology Data Exchange (ETDEWEB)

    Trent, M.A.

    1978-08-01

    Temperature-versus-time curves were recorded for various electronic components during pre-tinning, hand soldering, and drag soldering operations to determine the temperature ranges encountered. The component types investigated included a wide range of electronic assemblies. The data collected has been arranged by process and will help engineers to: (1) predetermine the thermal profile to which various components are subjected during the soldering operation; (2) decide--on the basis of component heat sensitivity and the need for thermal relief--where hand soldering would be more feasible than drag soldering; and (3) determine the optimum drag solder control parameters.

  15. Integrated environmentally compatible soldering technologies. Final report

    Energy Technology Data Exchange (ETDEWEB)

    Hosking, F.M.; Frear, D.R.; Iman, R.L.; Keicher, D.M.; Lopez, E.P.; Peebles, H.C.; Sorensen, N.R.; Vianco, P.T.

    1994-05-01

    Chemical fluxes are typically used during conventional electronic soldering to enhance solder wettability. Most fluxes contain very reactive, hazardous constituents that require special storage and handling. Corrosive flux residues that remain on soldered parts can severely degrade product reliability. The residues are removed with chlorofluorocarbon (CFC), hydrochlorofluorocarbon (HCFC), or other hazardous solvents that contribute to ozone depletion, release volatile organic compounds into the atmosphere, or add to the solvent waste stream. Alternative materials and processes that offer the potential for the reduction or elimination of cleaning are being developed to address these environmental issues. Timing of the effort is critical, since the targeted chemicals will soon be heavily taxed or banned. DOE`s Office of Environmental Restoration and Waste Management (DOE/EM) has supported Sandia National Laboratories` Environmentally Conscious Manufacturing Integrated Demonstration (ECMID). Part of the ECM program involves the integration of several environmentally compatible soldering technologies for assembling electronics devices. Fluxless or {open_quotes}low-residue/no clean{close_quotes} soldering technologies (conventional and ablative laser processing, controlled atmospheres, ultrasonic tinning, protective coatings, and environmentally compatible fluxes) have been demonstrated at Sandia (SNL/NM), the University of California at Berkeley, and Allied Signal Aerospace-Kansas City Division (AS-KCD). The university demonstrations were directed under the guidance of Sandia staff. Results of the FY93 Soldering ID are presented in this report.

  16. SNL initiatives in electronic fluxless soldering

    Science.gov (United States)

    Hosking, F. M.; Frear, D. R.; Vianco, P. T.; Keicher, D. M.

    Conventional soldering of electronic components generally requires the application of a chemical flux to promote solder wetting and flow. Chlorofluorocarbons (CFC) and halogenated solvents are normally used to remove the resulting flux residues. While such practice has been routinely accepted throughout the electronics industry, the environmental impact of hazardous solvents on ozone depletion will eventually limit or prevent their use. Solvent substitution or alternative technologies must be developed to meet these goals. Sandia National Laboratories (SNL), Albuquerque has a comprehensive environmentally conscious electronics manufacturing program underway that is funded by the DOE Office of Technology Development. Primary elements of the integrated task are the characterization and development of alternative fluxless soldering technologies that would eliminate circuit board cleaning associated with flux residue removal. Storage and handling of hazardous solvents and mixed solvent-flux waste would be consequently reduced during electronics soldering. This paper will report on the progress of the SNL fluxless soldering initiative. Emphasis is placed on the use of controlled atmospheres, laser heating, and ultrasonic soldering.

  17. PWB solder wettability after simulated storage

    Energy Technology Data Exchange (ETDEWEB)

    Hernandez, C.L.; Hosking, F.M.

    1996-03-01

    A new solderability test method has been developed at Sandia National Laboratories that simulates the capillary flow physics of solders on circuit board surfaces. The solderability test geometry was incorporated on a circuit board prototype that was developed for a National Center for Manufacturing Sciences (NCMS) program. The work was conducted under a cooperative research and development agreement between Sandia National Laboratories, NCMS, and several PWB fabricators (AT&T, IBM, Texas Instruments, United Technologies/Hamilton Standard and Hughes Aircraft) to advance PWB interconnect technology. The test was used to investigate the effects of environmental prestressing on the solderability of printed wiring board (PWB) copper finishes. Aging was performed in a controlled chamber representing a typical indoor industrial environment. Solderability testing on as-fabricated and exposed copper samples was performed with the Sn-Pb eutectic solder at four different reflow temperatures (215, 230, 245 and 260{degrees}C). Rosin mildly activated (RMA), low solids (LS), and citric acid-based (CA) fluxes were included in the evaluation. Under baseline conditions, capillary flow was minimal at the lowest temperatures with all fluxes. Wetting increased with temperature at both baseline and prestressing conditions. Poor wetting, however, was observed at all temperatures with the LS flux. Capillary flow is effectively restored with the CA flux.

  18. Use of organic solderability preservatives on solderability retention of copper after accelerated aging

    Energy Technology Data Exchange (ETDEWEB)

    Hernandez, C.L.; Sorensen, N.R.; Lucero, S.J.

    1997-02-01

    Organic solderability preservatives (OSP`s) have been used by the electronics industry for some time to maintain the solderability of circuit boards and components. Since solderability affects both manufacturing efficiency and product reliability, there is significant interest in maintaining good solder wettability. There is often a considerable time interval between the initial fabrication of a circuit board or component and its use at the assembly level. Parts are often stored under a variety of conditions, in many cases not well controlled. Solder wettability can deteriorate during storage, especially in harsh environments. This paper describes the ongoing efforts at Sandia National Laboratories to quantify solder watability on bare and aged copper surfaces. Benzotriazole and imidazole were applied to electronic grade copper to retard aging effects on solderability. The coupons were introduced into Sandia`s Facility for Atmospheric Corrosion Testing (FACT) to simulate aging in a typical indoor industrial environment. H{sub 2}S, NO{sub 2} and Cl{sub 2} mixed gas was introduced into the test cell and maintained at 35{degrees}C and 70% relative humidity for test periods of one day to two weeks. The OSP`s generally performed better than bare Cu, although solderability diminished with increasing exposure times.

  19. Corrosion resistance of the soldering joint of post-soldering of palladium-based metal-ceramic alloys.

    Science.gov (United States)

    Kawada, E; Sakurai, Y; Oda, Y

    1997-05-01

    To evaluate the corrosion resistance of post soldering of metal-ceramic alloys, four commercially available palladium-system metal-ceramic alloys (Pd-Cu, Pd-Ni, Pd-Ag, and Pd-Sb systems) and two types of solder (12 k gold solder and 16 k gold solder) with different compositions and melting points were used. The corrosion resistance of the soldered joint was evaluated by anodic polarization. The electrochemical characteristics of soldered surface were measured using electrochemical equipment. Declines in corrosion resistance were not detectable with Pd-Cu, Pd-Ag and Pd-Sb types, but break down at low potential occurred with Pd-Ni type.

  20. Royal London space analysis: plaster versus digital model assessment.

    Science.gov (United States)

    Grewal, Balpreet; Lee, Robert T; Zou, Lifong; Johal, Ama

    2016-08-10

    With the advent of digital study models, the importance of being able to evaluate space requirements becomes valuable to treatment planning and the justification for any required extraction pattern. This study was undertaken to compare the validity and reliability of the Royal London space analysis (RLSA) undertaken on plaster as compared with digital models. A pilot study (n = 5) was undertaken on plaster and digital models to evaluate the feasibility of digital space planning. This also helped to determine the sample size calculation and as a result, 30 sets of study models with specified inclusion criteria were selected. All five components of the RLSA, namely: crowding; depth of occlusal curve; arch expansion/contraction; incisor antero-posterior advancement and inclination (assessed from the pre-treatment lateral cephalogram) were accounted for in relation to both model types. The plaster models served as the gold standard. Intra-operator measurement error (reliability) was evaluated along with a direct comparison of the measured digital values (validity) with the plaster models. The measurement error or coefficient of repeatability was comparable for plaster and digital space analyses and ranged from 0.66 to 0.95mm. No difference was found between the space analysis performed in either the upper or lower dental arch. Hence, the null hypothesis was accepted. The digital model measurements were consistently larger, albeit by a relatively small amount, than the plaster models (0.35mm upper arch and 0.32mm lower arch). No difference was detected in the RLSA when performed using either plaster or digital models. Thus, digital space analysis provides a valid and reproducible alternative method in the new era of digital records.

  1. Influence of Trimetazidine Hydrochloride on cardiovascular index in young solder after exercise%青年士兵运动后心血管相关指标的变化及盐酸曲美他嗪的影响

    Institute of Scientific and Technical Information of China (English)

    张国明; 李晓燕; 刘娟; 孙青; 许家雨

    2013-01-01

    Objective To investigate the effect of trimetazidine hydrochloride on myocardial injury and endothelial function in high risk populations of cardiovascular disease after military training exercise. Methods In 960 soldiers, using a questionnaire survey (including family history of heart disease, past history, heart disease risk factors and symptoms after exercise), physical examination and electrocardiogram, we selected high-risk populations. High risk groups were randomly divided into trimetazidine group and high risk control group, and the same numbers of solders with equivalent age in low risk were selected as low risk control group. Trimetazidine group were given trimetazidine before exercise 7 days (20 mg, 3 times daily, orally), low risk control group and high risk control group were not given drug. Comparison of heart rate, blood pressure and ECG changes, and plasma epinephrine, nitric oxide and heart-type fatty acid binding protein concentration changes were done between three groups before and after exercise. Results There were no difference between three groups before exercise in heart rate, blood pressure and all kinds of biochemical indices. The indicators of the three groups were increased in different degree after exercise. So heart rate and blood pressure product[(11 209.8±154.7) mm Hg·bpm vs. (11 514.9±180.4) mm Hg·bpm, P<0.05], Plasma concentrations of epinephrine[(106.3±10.7)ng/L vs. (111.1±10.3)ng/L, P < 0.05], concentration of high sensitivity C reactive protein[(30.3±6.5)μg/L vs. (33.9±5.8)μg/L, P<0.05] and concentration of heart-type fatty acid binding protein[(648.8±60.9)pg/ml vs. (659.1±67.2)pg/ml, P<0.05] in Trimetazidine hydrochloride group were all significantly lower than those in high risk control group, and concentration of nitric oxide [(112.7±11.4)μmol/L vs.(108.3±9.7)μmol/L, P<0.05] was higher than that in high risk control group. Conclusion Trimetazidine hydrochloride can significantly reduce stress response, improve

  2. Indexed

    CERN Document Server

    Hagy, Jessica

    2008-01-01

    Jessica Hagy is a different kind of thinker. She has an astonishing talent for visualizing relationships, capturing in pictures what is difficult for most of us to express in words. At indexed.blogspot.com, she posts charts, graphs, and Venn diagrams drawn on index cards that reveal in a simple and intuitive way the large and small truths of modern life. Praised throughout the blogosphere as “brilliant,” “incredibly creative,” and “comic genius,” Jessica turns her incisive, deadpan sense of humor on everything from office politics to relationships to religion. With new material along with some of Jessica’s greatest hits, this utterly unique book will thrill readers who demand humor that makes them both laugh and think.

  3. Age-aware solder performance models : level 2 milestone completion.

    Energy Technology Data Exchange (ETDEWEB)

    Neilsen, Michael K.; Vianco, Paul Thomas; Neidigk, Matthew Aaron; Holm, Elizabeth Ann

    2010-09-01

    Legislated requirements and industry standards are replacing eutectic lead-tin (Pb-Sn) solders with lead-free (Pb-free) solders in future component designs and in replacements and retrofits. Since Pb-free solders have not yet seen service for long periods, their long-term behavior is poorly characterized. Because understanding the reliability of Pb-free solders is critical to supporting the next generation of circuit board designs, it is imperative that we develop, validate and exercise a solder lifetime model that can capture the thermomechanical response of Pb-free solder joints in stockpile components. To this end, an ASC Level 2 milestone was identified for fiscal year 2010: Milestone 3605: Utilize experimentally validated constitutive model for lead-free solder to simulate aging and reliability of solder joints in stockpile components. This report documents the completion of this milestone, including evidence that the milestone completion criteria were met and a summary of the milestone Program Review.

  4. Mortality among unionized construction plasterers and cement masons.

    Science.gov (United States)

    Stern, F; Lehman, E; Ruder, A

    2001-04-01

    Plasterers perform a variety of duties including interior and exterior plastering of drywall, cement, stucco, and stone imitation; the preparation, installation, and repair of all interior and exterior insulation systems; and the fireproofing of steel beams and columns. Some of the current potential toxic exposures among plasterers include plaster of Paris, silica, fiberglass, talc, and 1,1,1-trichloroethylene; asbestos had been used by the plasterers in the past. Cement masons, on the other hand, are involved in concrete construction of buildings, bridges, curbs and gutters, sidewalks, highways, streets and roads, floors and pavements and the finishing of same, when necessary, by sandblasting or any other method. Exposures include cement dust, silica, asphalt, and various solvents. Proportionate mortality ratios (PMRs) and proportionate cancer mortality ratios (PCMRs) were calculated for 99 causes of death among 12,873 members of the Operative Plasterers' and Cement Masons' International Association who died between 1972 and 1996 using United States age-, race-, and calender-specific death rates. Statistical significance (P value) of results was based upon the Poisson distribution. Among plasterers, statistically significant elevated mortality was observed for asbestosis, where the PMR reached 1,657 (P < 0.01) with eleven observed deaths and less than one death expected, for lung cancer (PCMR = 124, P < 0.01), and for benign neoplasms (PMR = 210, P < 0.05). Among cement masons, statistically significant elevated mortality was observed for cancer of the stomach (PCMR = 133, P < 0.01), benign neoplasms (PMR = 132, P < 0.01), and poisonings (PMR = 159, P < 0.05). Except for poisonings, which were not thought to be occupationally related, all of the statistically significant results occurred among those members who entered the union prior to 1950. However, the risk for lung cancer among plasterers was still elevated among those entering the union after 1970 as was the

  5. Computer simulation of solder joint failure

    Energy Technology Data Exchange (ETDEWEB)

    Burchett, S.N.; Frear, D.R. [Sandia National Lab., Albuquerque, NM (United States); Rashid, M.M. [Univ. of California, Davis, CA (United States)

    1997-04-01

    The thermomechanical fatigue failure of solder joints is increasingly becoming an important reliability issue for electronic packages. The purpose of this Laboratory Directed Research and Development (LDRD) project was to develop computational tools for simulating the behavior of solder joints under strain and temperature cycling, taking into account the microstructural heterogeneities that exist in as-solidified near eutectic Sn-Pb joints, as well as subsequent microstructural evolution. The authors present two computational constitutive models, a two-phase model and a single-phase model, that were developed to predict the behavior of near eutectic Sn-Pb solder joints under fatigue conditions. Unique metallurgical tests provide the fundamental input for the constitutive relations. The two-phase model mathematically predicts the heterogeneous coarsening behavior of near eutectic Sn-Pb solder. The finite element simulations with this model agree qualitatively with experimental thermomechanical fatigue tests. The simulations show that the presence of an initial heterogeneity in the solder microstructure could significantly degrade the fatigue lifetime. The single-phase model was developed to predict solder joint behavior using materials data for constitutive relation constants that could be determined through straightforward metallurgical experiments. Special thermomechanical fatigue tests were developed to give fundamental materials input to the models, and an in situ SEM thermomechanical fatigue test system was developed to characterize microstructural evolution and the mechanical behavior of solder joints during the test. A shear/torsion test sample was developed to impose strain in two different orientations. Materials constants were derived from these tests. The simulation results from the two-phase model showed good fit to the experimental test results.

  6. Evaluation technology of lead-free solders; Namari free handa zairyo ni okeru hyoka gijutsu

    Energy Technology Data Exchange (ETDEWEB)

    Yamashita, M.; Shiokawa, K. [Fuji Electric Co. Ltd., Tokyo (Japan); Ueda, A. [Fuji Electric Corporate Research and Development,Ltd., Kanagawa (Japan)

    2000-09-10

    Solders mainly composed of tin and lead are currently in widespread use in semiconductor devices. However, in view of lead influences on the human body and environmental problems, lead-free solders have been in urgent demand. In this study, aiming to improve the solderability and reliability of a tin-silver solder, one of most promising lead-free solder materials, we have investigated elements to be added. Focusing on typical lead-free tin-silver solders and tin-lead eutectic solders, this paper describes the result of investigations into the mechanical properties solderability, micro structures of the solder materials and gas analysis in soldering. (author)

  7. Accuracy of stereolithographically printed digital models compared to plaster models.

    Science.gov (United States)

    Camardella, Leonardo Tavares; Vilella, Oswaldo V; van Hezel, Marleen M; Breuning, Karel H

    2017-03-30

    This study compared the accuracy of plaster models from alginate impressions and printed models from intraoral scanning. A total of 28 volunteers were selected and alginate impressions and intraoral scans were used to make plaster models and digital models of their dentition, respectively. The digital models were printed using a stereolithographic (SLA) 3D printer with a horseshoe-shaped design. Two calibrated examiners measured distances on the plaster and printed models with a digital caliper. The paired t test was used to determine intraobserver error and compare the measurements. The Pearson correlation coefficient was used to evaluate the reliability of measurements for each model type. The measurements on plaster models and printed models show some significant differences in tooth dimensions and interarch parameters, but these differences were not clinically relevant, except for the transversal measurements. The upper and lower intermolar distances on the printed models were statistically significant and clinically relevant smaller. Printed digital models with the SLA 3D printer studied, with a horseshoe-shaped base made from intraoral scans cannot replace conventional plaster models from alginate impressions in orthodontics for diagnosis and treatment planning because of their clinically relevant transversal contraction.

  8. Thermophysical properties of hydrophobised lime plasters - The influence of ageing

    Science.gov (United States)

    Pavlíková, Milena; Zemanová, Lucie; Pavlík, Zbyšek

    2017-07-01

    The building envelope is a principal responsible for buildings energy loses. Lime plasters as the most popular finishing materials of historical buildings and culture monuments influence the thermal behaviour as well as construction material of masonry. On this account, the effect of ageing on the thermophysical properties of a newly designed lime plasters containing hydrophobic admixture is analysed in the paper. For the comparative purposes, the reference lime plaster is tested. The ageing is accelerated with controlled carbonation process to simulate the final plasters properties. Basic characterization of the tested materials is done using bulk density, matrix density, and porosity measurements. Thermal conductivity and volumetric heat capacity are experimentally assessed using a transient impulse method. The obtained data revealed the significant changes of the both studied thermal parameters in the dependence on plasters composition and age. The assessed material parameters will be stored in a material database, where will find use as an input data for computational modelling of heat transport in this type of porous building materials and evaluation of energy-savings and sustainability issues.

  9. 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[...

  10. 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.

  11. Microstructural evolution of eutectic Au-Sn solder joints

    Energy Technology Data Exchange (ETDEWEB)

    Song, Ho Geon

    2002-05-31

    Current trends toward miniaturization and the use of lead(Pb)-free solder in electronic packaging present new problems in the reliability of solder joints. This study was performed in order to understand the microstructure and microstructural evolution of small volumes of nominally eutectic Au-Sn solder joints (80Au-20Sn by weight), which gives insight into properties and reliability.

  12. Microstructural evolution of eutectic Au-Sn solder joints

    Energy Technology Data Exchange (ETDEWEB)

    Song, Ho Geon [Univ. of California, Berkeley, CA (United States)

    2002-05-01

    Current trends toward miniaturization and the use of lead(Pb)-free solder in electronic packaging present new problems in the reliability of solder joints. This study was performed in order to understand the microstructure and microstructural evolution of small volumes of nominally eutectic Au-Sn solder joints (80Au-20Sn by weight), which gives insight into properties and reliability.

  13. Testing of printed circuit board solder joints by optical correlation

    Science.gov (United States)

    Espy, P. N.

    1975-01-01

    An optical correlation technique for the nondestructive evaluation of printed circuit board solder joints was evaluated. Reliable indications of induced stress levels in solder joint lead wires are achievable. Definite relations between the inherent strength of a solder joint, with its associated ability to survive stress, are demonstrable.

  14. 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

    Purpose:The aim of this work is to investigate the decomposition behaviour of the activator species commonly used in the wave solder no-clean flux systems and to estimate the residue amount left after subjecting the samples to simulated wave soldering conditions. Design/methodology/approach: Chan......Purpose:The aim of this work is to investigate the decomposition behaviour of the activator species commonly used in the wave solder no-clean flux systems and to estimate the residue amount left after subjecting the samples to simulated wave soldering conditions. Design....../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......-malic). The decomposition patterns of solder flux activators depend on their chemical nature, time of heat exposure and substrate materials. Evaporation of the residue from the surface of different materials (laminate with solder mask, copper surface or glass surface) was found to be more pronounced for succinic...

  15. A Study of the Interface of Soldered Joints of SnInAgTi Active Solder with Ito Ceramics

    OpenAIRE

    M. Provazník; R. Koleňák

    2010-01-01

    This paper presents an analysis of the solderability ITO ceramics (In2O3/SnO2). The soft active solder SnInAgeTi was used for the experiments. The solder was activated by power ultrasound in air without flux. An analysis of the interface of the phases between the solder and the ceramic was carried out in order to discover the ultrasonic impacts on the active metal and to identify the mechanism of the joint on the ceramic side.

  16. 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..

  17. Does cutting a plaster window weaken its strength?

    Science.gov (United States)

    Patel, Nimesh; Wilson, Lance; Wansbrough, Guy

    2017-03-01

    A plaster window is usually created over a pressure area, or in some cases a wound or suture line. This can relieve pressure at the site, and provide an opportunity to change dressings, check on drainage, and inspect a wound or ulcer. There is concern that this can have an effect on its function to provide fracture stability, and weakens the plaster. The biomechanical effects of windowing on plaster strength were therefore investigated, as it has not previously been reported. A laboratory study was undertaken to compare the bending, kinking and torsion loads withstood by standardised Plaster of Paris (POP), Softcast and Fibreglass casts compared to those with a 60×40mm window fabricated in the centre at clinically defined endpoints using an Instron machine. The addition of a window significantly weakened the load to failure of POP; Fibreglass, and Softcast by 23.1% (473.1N); 25.9% (401.8N), and 29% (146.6N) respectively, during the 4-point bending tests. During the 3-point kinking tests, load to failure was reduced by 38.5% (297.8N); 35.3% (146.9N), and 51.5% (103.8N) respectively. All tests were checked for consistency and carried out in a single orthogonal plane for ease of comparison. The addition of a 60×40mm window to a cast made up of POP, Fibreglass or Softcast weakens the cast load to failure by up to 51% against a 3-point loading force. Though windowing of casts is necessary in certain situations, we advise precautions such as adding further layers of plaster to the window site, keeping the window as small as possible, and advising the patient of the increased risk of weakening and failure of the plaster so that they can take more care. Copyright © 2017 Elsevier Ltd. All rights reserved.

  18. Capillary wave formation on excited solder jet and fabrication of lead-free solder ball

    Institute of Scientific and Technical Information of China (English)

    ZHANG Shu-guang; HE Li-jun; ZHU Xue-xin; ZHANG Shao-ming; SHI Li-kai; XU Jun

    2005-01-01

    A survey of solder ball production processes especially focusing on disturbed molten metal jet breakup process was made. Then the formation of capillary wave on tin melt jet in the way of rapid solidification was studied. A semi-empirical formula, which can be written as λ = Cvib (σ/ρ)1/3f-2/3 to predict the relationship between wavelength of capillary wave and frequency of imposed vibration was obtained. Sn-4.0Ag-0.5Cu lead free solder ball was successfully produced with tight distribution and good sphericity. The excited jet breakup process is promising for cost effectively producing solder ball.

  19. Solder Joint Health Monitoring Testbed System

    Science.gov (United States)

    Delaney, Michael M.

    2009-01-01

    The density and pin count for Field Programmable Gate Arrays (FPGAs) has been increasing, and has exceeded current methods of solder joint inspection, making early detection of failures more problematic. These failures are a concern for both flight safety and maintenance in commercial aviation. Ridgetop Group, Inc. has developed a method for detecting solder joint failures in real time. The NASA Dryden Flight Research Center is developing a set of boards to test this method in ground environmental and accelerated testing as well as flight test on a Dryden F-15 or F-18 research aircraft. In addition to detecting intermittent and total solder joint failures, environmental data on the boards, such as temperature and vibration, will be collected and time-correlated to aircraft state data. This paper details the technical approach involved in the detection process, and describes the design process and products to date for Dryden s FPGA failure detection boards.

  20. Pb-Free Soldering Iron Temperature Controller

    Science.gov (United States)

    Hamane, Hiroto; Wajima, Kenji; Hayashi, Yoichi; Komiyama, Eiichi; Tachibana, Toshiaki; Miyazaki, Kazuyoshi

    Recently, much importance has been attached to the environmental problem. The content of two directives to better control the management of waste electronic equipment was approved. The two directives are the Waste from Electrical and Electronic Equipment (WEEE) and the Restriction of Hazardous Substances (RoHS). These set phase-out dates for the use of lead materials contained in electronic products. Increasingly, attention is focusing on the potential use of Pb-free soldering in electronics manufacturing. It should be noted that many of the current solding irons are not suitable for Pb-free technology, due to the inferior wetting ability of Pb-free alloys compared with SnPb solder pastes. This paper presents a Pb-free soldering iron temperature controller using an embedded micro-processor with a low memory capacity.

  1. Nanocopper Based Solder-Free Electronic Assembly

    Science.gov (United States)

    Schnabl, K.; Wentlent, L.; Mootoo, K.; Khasawneh, S.; Zinn, A. A.; Beddow, J.; Hauptfleisch, E.; Blass, D.; Borgesen, P.

    2014-12-01

    CuantumFuse nano copper material has been used to assemble functional LED test boards and a small camera board with a 48 pad CMOS sensor quad-flat no-lead chip and a 10 in flexible electronics demo. Drop-in replacement of solder, by use of stencil printing and standard surface mount technology equipment, has been demonstrated. Applications in space and commercial systems are currently under consideration. The stable copper-nanoparticle paste has been examined and characterized by scanning electron microscopy and high-resolution transmission electron microscopy; this has shown that the joints are nanocrystalline but with substantial porosity. Assessment of reliability is expected to be complicated by this and by the effects of thermal and strain-enhanced coarsening of pores. Strength, creep, and fatigue properties were measured and results are discussed with reference to our understanding of solder reliability to assess the potential of this nano-copper based solder alternative.

  2. Moisture and aging effects of solder wettability of copper surfaces

    Energy Technology Data Exchange (ETDEWEB)

    Hernandez, C.L.; Sorensen, N.R.; Lucero, S.J.

    1996-12-01

    Solderability is a critical property of electronic assembly that affects both manufacturing efficiency and product reliability. There is often a considerable time interval between initial fabrication of a circuit board or component and its use at the assembly level. Parts are often stored under a variety of conditions, usually not controlled. Solder wettability can soon deteriorate during storage, especially in extreme environments. This paper describes ongoing efforts at Sandia to quantify solder wettability on bare and aged Cu surfaces. In addition, organic solderability preservatives (OSPs) were applied to the bare Cu to retard solderability loss due to aging. The OSPs generally performed well, although wetting did decrease with exposure time.

  3. Parametric study on the solderability of etched PWB copper

    Energy Technology Data Exchange (ETDEWEB)

    Hosking, F.M.; Stevenson, J.O.; Hernandez, C.L.

    1996-10-01

    The rapid advancement of interconnect technology has resulted in a more engineered approach to designing and fabricating printed wiring board (PWB) surface features. Recent research at Sandia National Laboratories has demonstrated the importance of surface roughness on solder flow. This paper describes how chemical etching was used to enhance the solderability of surfaces that were normally difficult to wet. The effects of circuit geometry, etch concentration, and etching time on solder flow are discussed. Surface roughness and solder flow data are presented. The results clearly demonstrate the importance of surface roughness on the solderability of fine PWB surface mount features.

  4. Three-dimensional photographs for determining the Index of Orthodontic Treatment Need in scientific studies

    NARCIS (Netherlands)

    Kragt, L.; Hermus, A.M.; Wolvius, E.B.; Ongkosuwito, E.M.

    2016-01-01

    INTRODUCTION: Plaster casts as the medium for data collection in orthodontic studies pose disadvantages. In this study, we aimed to assess the validity and reliability of using 3-dimensional (3D) photographs instead of plaster casts to determine the Index of Orthodontic Treatment Need (IOTN) score.

  5. Lead (Pb)-Free Solder Applications

    Energy Technology Data Exchange (ETDEWEB)

    VIANCO,PAUL T.

    2000-08-15

    Legislative and marketing forces both abroad and in the US are causing the electronics industry to consider the use of Pb-free solders in place of traditional Sn-Pb alloys. Previous case studies have demonstrated the satisfactory manufacturability and reliability of several Pb-free compositions for printed circuit board applications. Those data, together with the results of fundamental studies on Pb-free solder materials, have indicated the general feasibility of their use in the broader range of present-day, electrical and electronic components.

  6. Effects of PCB thickness on adjustable fountain wave soldering

    Indian Academy of Sciences (India)

    M S Abdul Aziz; M Z Abdullah; C Y Khor; A Jalar; M A Bakar; W Y W Yusoff; F Che Ani; Nobe Yan; M Zhou; C Cheok

    2015-10-01

    This study investigates the effects of printed circuit board (PCB) thickness on adjustable fountain and conventional wave soldering. The pin-through-hole (PTH) vertical fill is examined with three PCBs of different thicknesses (i.e., 1.6, 3.1, and 6.0 mm) soldered through adjustable fountain and conventional wave soldering at conveyor angles of 0° and 6°. The vertical fill of each PCB is the focus. The PTH solder profile is inspected with a non-destructive X-ray computed tomography scanning machine. The percentages of the PTH vertical fill of both soldering processes are also estimated and compared. The aspect ratio of the PCB is also investigated. Experimental results reveal that adjustable fountain wave soldering yields better vertical fill than conventional wave soldering. The vertical fill level of adjustable fountain wave soldering is 100%, 90%, and 50% for the 1.6, 3.1, and 6.0 mm PCB thickness, respectively. FLUENT simulation is conducted for the vertical fill of the solder profile. Simulation and experimental results show that the PTH solder profiles of the two soldering processes are almost identical. The effect of PCB thickness on PTH voiding is also discussed.

  7. Solder flow over fine line PWB surface finishes

    Energy Technology Data Exchange (ETDEWEB)

    Hosking, F.M.; Hernandez, C.L.

    1998-08-01

    The rapid advancement of interconnect technology has stimulated the development of alternative printed wiring board (PWB) surface finishes to enhance the solderability of standard copper and solder-coated surfaces. These new finishes are based on either metallic or organic chemistries. As part of an ongoing solderability study, Sandia National Laboratories has investigated the solder flow behavior of two azole-based organic solderability preservations, immersion Au, immersion Ag, electroless Pd, and electroless Pd/Ni on fine line copper features. The coated substrates were solder tested in the as-fabricated and environmentally-stressed conditions. Samples were processed through an inerted reflow machine. The azole-based coatings generally provided the most effective protection after aging. Thin Pd over Cu yielded the best wetting results of the metallic coatings, with complete dissolution of the Pd overcoat and wetting of the underlying Cu by the flowing solder. Limited wetting was measured on the thicker Pd and Pd over Ni finishes, which were not completely dissolved by the molten solder. The immersion Au and Ag finishes yielded the lowest wetted lengths, respectively. These general differences in solderability were directly attributed to the type of surface finish which the solder came in contact with. The effects of circuit geometry, surface finish, stressing, and solder processing conditions are discussed.

  8. Prototype circuit boards assembled with non-lead bearing solders

    Energy Technology Data Exchange (ETDEWEB)

    Vianco, P.T.; Rejent, J.A.

    1998-04-01

    The 91.84Sn-3.33Ag-4.83Bi and 96.5Sn-3.5Ag Pb-free solders were evaluated for surface mount circuit board interconnects. The 63Sn-37Pb solder provided the baseline data. All three solders exhibited suitable manufacturability per a defect analyses of circuit board test vehicles. Thermal cycling had no significant effect on the 91.84Sn-3.33Ag-4.83Bi solder joints. Some degradation in the form of grain boundary sliding was observed in 96.5Sn-3.5Ag and 63Sn-37Pb solder joints. The quality of the solder joint microstructures showed a slight degree of degradation under thermal shock exposure for all of the solders tested. Trends in the solder joint shear strengths could be traced to the presence of Pd in the solder, the source of which was the Pd/Ni finish on the circuit board conductor features. The higher, intrinsic strengths of the Pb-free solders encouraged the failure path to be located in proximity to the solder/substrate interface where Pd combined with Sn to form brittle PdSn{sub 4} particles, resulting in reduced shear strengths.

  9. Capillary flow of solder on chemically roughened PWB surfaces

    Energy Technology Data Exchange (ETDEWEB)

    Hosking, F.M.; Stevenson, J.O.; Yost, F.G.

    1996-02-01

    The Center for Solder Science and Technology at Sandia National Laboratories has developed a solderability test for evaluating fundamental solder flow over PWB (printed wiring boards) surface finishes. The work supports a cooperative research and development agreement between Sandia, the National Center for Manufacturing Sciences (NCMS), and several industrial partners. An important facet of the effort involved the ``engineering`` of copper surfaces through mechanical and chemical roughening. The roughened topography enhances solder flow, especially over very fine features. In this paper, we describe how etching with different chemical solutions can affect solder flow on a specially designed ball grid array test vehicle (BGATV). The effects of circuit geometry, solution concentration, and etching time are discussed. Surface roughness and solder flow data are presented to support the roughening premise. Noticeable improvements in solder wettability were observed on uniformly etched surfaces having relatively steep peak-to-valley slopes.

  10. Automatic computer-aided system of simulating solder joint formation

    Science.gov (United States)

    Zhao, Xiujuan; Wang, Chunqing; Zheng, Guanqun; Wang, Gouzhong; Yang, Shiqin

    1999-08-01

    One critical aspect in electronic packaging is the fatigue/creep-induced failure in solder interconnections, which is found to be highly dependent on the shape of solder joints. Thus predicting and analyzing the solder joint shape is warranted. In this paper, an automatic computer-aided system is developed to simulate the formation of solder joint and analyze the influence of the different process parameters on the solder joint shape. The developed system is capable of visually designing the process parameters and calculating the solder joint shape automatically without any intervention from the user. The automation achieved will enable fast shape estimation with the variation of process parameters without time consuming experiments, and the simulating system provides the design and manufacturing engineers an efficient software tools to design soldering process in design environment. Moreover, a program developed from the system can serve as the preprocessor for subsequent finite element joint analysis program.

  11. The Material Behavior Of Plastered-Bamboo Wall Towards Lateral Loads

    OpenAIRE

    V. R. R. Hutubessy,; Hrc. Priyosulistyo

    2014-01-01

    This study determined the lateral resistance capacity of the plastered-bamboo wall. The test was carried out on three pieces of plastered-bamboo wall. The first was plastered-bamboo wall without bracing (DP-TB), second was plastered-bamboo wall using bamboo bracing (DP-BB), and the last is a plastered-bamboo wall which uses wiremesh bracing (DP-BK). The static load (monotonic) test method was used to determine the correlation between the lateral resistance and the deflection o...

  12. Auricular-Plaster Therapy for Treatment of IBS

    Institute of Scientific and Technical Information of China (English)

    敖学艳; 王宁

    2004-01-01

    @@ Irritable bowel syndrome (IBS), a disease of the digestive system related to mental factors, is clinically characterized by diarrhea (or alternation of diarrhea and constipation) and abdominal pain. In recent years, the authors have used auricular-plaster therapy plus pressing on the back-shu points to treat IBS, and obtained good therapeutic results.

  13. Roughness of surface of vacuum castings prepared in plaster moulds

    Directory of Open Access Journals (Sweden)

    M. Pawlak

    2011-07-01

    Full Text Available The results of researches on surface roughness of CuSn10 and CuSn5Zn5Pb5 bronzes and aluminum AlSi11 alloy vacuum castings prepared in plaster moulds are presented in this paper. Test samples were cut from stripe castings of dimensions 100x15x1 mm. Surfaces were carefully cleaned with use of soft brush than in ultrasonic washer and dried. Experimental castings were prepared in moulds made of two types of plaster. Cast temperatures were 1120 and 1200°C for bronzes and 700 and 800°C for silumin. Temperatures of the mould were 500 and 600°C for bronzes and 200 and 300°C for aluminum alloy. The roughness measurements were carried out with use of Hommelwerke Tester T1000. The average arithmetic deviation of roughness profile Ra, the ten-point height of irregularities Rz and maximum peak to valley height Rm, were measured.It can be stated, on the base of obtained results, that technology of casting in plaster moulds allows preparation of castings of very low roughness, average Ra=0,88÷1,74μm for bronzes and Ra=0,59÷0,83μm for aluminum alloys. Roughness of the surface depends in fact on the cast material. Type of plaster and casting parameters have negligible influence on it.

  14. [Treatment of persistent postmastectomy pain with 5% Lidocaine medicated plaster].

    Science.gov (United States)

    Cruto, M E; Baricocchi, E; Battistella, M; Bona, F; Giacoletto, G; Iacobellis, A; Moselli, N; Palomba, G; Sardo, E; Savojardo, M; Suita, L; Zocca, E; Debernardi, F

    2015-04-01

    Persistent postmastectomy pain (PPMP) syndrome is characterized by neuropathic pain that develops following surgery in breast cancer patients. The reported incidence of PPMP ranges between 30% and 50% and is estimated to increase as the number of women surviving cancer continues to rise. Though effective, today's drug treatments are poorly tolerated, limiting their use and reducing adherence to therapy. Since neuropathic pain is localized, international guidelines suggest that topical treatment with 5% Lidocaine medicated plaster either alone or combined with systemic drugs can be considered for pain management. In this retrospective study we reviewed the medical records of 11 patients treated with 5% lidocaine medicated plaster for moderate-to-severe PPMP at our institute between November 2013 and October 2014. Analysis showed that treatment with 5% Lidocaine medicated plaster, either alone or in combination with systemic drugs, achieved significant pain control already after the first week of therapy. The effectiveness and tolerability of 5% Lidocaine medicated plaster we observed suggests that it is a viable option in the management of PPMP.

  15. Plastering. Pre-Apprenticeship Phase 2 Training. Student Training Modules.

    Science.gov (United States)

    Hamblen, Ron

    These 20 Student Training Modules on plastering comprise one of nine sets of self-paced learning modules developed for Pre-Apprenticeship Phase 2 Training. (A companion instructor's guide is available separately as CE 031 569.) The modules are designed to impart trade knowledge and skills to the student. Each module contains some or all of the…

  16. No local recurrence of enchondroma after curettage and plaster filling.

    NARCIS (Netherlands)

    Gaasbeek, R.D.A.; Rijnberg, W.J.; Loon, C.J.M. van; Meyers, H.; Feith, R.

    2005-01-01

    INTRODUCTION: The most common treatment of enchondromas is curettage (with or without adjuvant therapy) followed by cancellous bone grafting. To avoid donor-site morbidity of the iliac crest, we applied plaster of Paris as a bone defect filler after curettage of enchondromas. MATERIALS AND METHODS:

  17. Analysis of transport and crystallisation of salts in restoration plasters

    NARCIS (Netherlands)

    Hees, R.P.J. van; Lubelli, B.

    2002-01-01

    For the understanding of the salt crystallisation mechanism in restoration plasters, the understanding of water (moisture) transport is essential, as it is the influence of salts on the water transport. More specifically the drying behaviour, i.e. the moisture / salt transport and distribution durin

  18. Microstructural Evolution of Lead-Free Solder Joints in Ultrasonic-Assisted Soldering

    Science.gov (United States)

    Ji, Hongjun; Wang, Qiang; Li, Mingyu

    2016-01-01

    Solder joint reliability greatly depends on the microstructure of the solder matrix and the morphology of intermetallic compounds (IMCs) in the joints. Addition of strengthening phases such as carbon nanotubes and ceramic particles to solder joints to improve their properties has been widely studied. In this work, ultrasonic vibration (USV) of casting ingots was applied to considerably improve their microstructure and properties, and the resulting influence on fluxless soldering of Cu/Sn-3.0Ag-0.5Cu/Cu joints and their microstructural evolution was investigated. It was demonstrated that USV application during reflow of Sn-based solder had favorable effects on β-Sn grain size refinement as well as the growth and distribution of various IMC phases within the joints. The β-Sn grain size was significantly refined as the ultrasound power was increased, with a reduction of almost 90% from more than 100 μm to below 10 μm. Long and large Cu6Sn5 tubes in the solder matrix of the joints were broken into tiny ones. Needle-shaped Ag3Sn was transformed into flake-shaped. These IMCs were mainly precipitated along β-Sn phase boundaries. High-temperature storage tests indicated that the growth rate of interfacial IMCs in joints formed with USV was slower than in conventional reflow joints. The mechanisms of grain refinement and IMC fragmentation are discussed and related to the ultrasonic effects.

  19. The Material Behavior Of Plastered-Bamboo Wall Towards Lateral Loads

    Directory of Open Access Journals (Sweden)

    V. R. R. Hutubessy,

    2014-01-01

    Full Text Available This study determined the lateral resistance capacity of the plastered-bamboo wall. The test was carried out on three pieces of plastered-bamboo wall. The first was plastered-bamboo wall without bracing (DP-TB, second was plastered-bamboo wall using bamboo bracing (DP-BB, and the last is a plastered-bamboo wall which uses wiremesh bracing (DP-BK. The static load (monotonic test method was used to determine the correlation between the lateral resistance and the deflection of plastered-bamboo wall. The monotonic testing was only conducted until the load has experience 20% decrease from peak load. The test results showed that the plastered-bamboo wall using wiremesh bracing had the peak load capacity, energy dissipation, and higher ductility than the plastered-bamboo wall using bamboo bracing. Elastic stiffness of the plastered-bamboo wall using bamboo bracing was 1.27 greater than plastered-bamboo wall using wiremesh bracing. The ultimate load resulted from the experiment of the plastered-bamboo wall with either bamboo or additional wiremeshbracingwas 25.52 kN and 26.37 kN or two times greater than the results of an analysis of the flexural failure based on Subedi method (1991 which was 14.39 kN.

  20. Multilead, Vaporization-Cooled Soldering Heat Sink

    Science.gov (United States)

    Rice, John

    1995-01-01

    Vaporization-cooled heat sink proposed for use during soldering of multiple electrical leads of packaged electronic devices to circuit boards. Heat sink includes compliant wicks held in grooves on edges of metal fixture. Wicks saturated with water. Prevents excessive increases in temperature at entrances of leads into package.

  1. Soldering and Mass Generation in Four Dimensions

    CERN Document Server

    Banerjee, R; Banerjee, Rabin; Wotzasek, Clovis

    2000-01-01

    We propose bosonised expressions for the chiral Schwinger models in four dimensions. Then, in complete analogy with the two dimensional case, we show the soldering of two bosonised chiral Schwinger models with opposite chiralities to yield the bosonised Schwinger model in four dimensions. The implications of the Schwinger model or its chiral version, as known for two dimensions, thereby get extended to four dimensions.

  2. Solderability test development. Final report. [Meniscograph tests

    Energy Technology Data Exchange (ETDEWEB)

    Jarboe, D.M.

    1977-10-01

    Operating procedures and data reduction techniques applicable to the Meniscograph (General Electric Company, Limited) were developed. Using force-time traces from tests involving various sample materials and configurations, flux types, and test temperatures, the wetting rate and contact angle were obtained through statistical treatment of the data. This information provides a means of directly correlating solderability with the physical phenomenon of wetting.

  3. Measurements using orthodontic analysis software on digital models obtained by 3D scans of plaster casts : Intrarater reliability and validity.

    Science.gov (United States)

    Czarnota, Judith; Hey, Jeremias; Fuhrmann, Robert

    2016-01-01

    The purpose of this work was to determine the reliability and validity of measurements performed on digital models with a desktop scanner and analysis software in comparison with measurements performed manually on conventional plaster casts. A total of 20 pairs of plaster casts reflecting the intraoral conditions of 20 fully dentate individuals were digitized using a three-dimensional scanner (D700; 3Shape). A series of defined parameters were measured both on the resultant digital models with analysis software (Ortho Analyzer; 3Shape) and on the original plaster casts with a digital caliper (Digimatic CD-15DCX; Mitutoyo). Both measurement series were repeated twice and analyzed for intrarater reliability based on intraclass correlation coefficients (ICCs). The results from the digital models were evaluated for their validity against the casts by calculating mean-value differences and associated 95 % limits of agreement (Bland-Altman method). Statistically significant differences were identified via a paired t test. Significant differences were obtained for 16 of 24 tooth-width measurements, for 2 of 5 sites of contact-point displacement in the mandibular anterior segment, for overbite, for maxillary intermolar distance, for Little's irregularity index, and for the summation indices of maxillary and mandibular incisor width. Overall, however, both the mean differences between the results obtained on the digital models versus on the plaster casts and the dispersion ranges associated with these differences suggest that the deviations incurred by the digital measuring technique are not clinically significant. Digital models are adequately reproducible and valid to be employed for routine measurements in orthodontic practice.

  4. Microwave Tissue Soldering for Immediate Wound Closure

    Science.gov (United States)

    Arndt, G. Dickey; Ngo, Phong H.; Phan, Chau T.; Byerly, Diane; Dusl, John; Sognier, Marguerite A.; Carl, James

    2011-01-01

    A novel approach for the immediate sealing of traumatic wounds is under development. A portable microwave generator and handheld antenna are used to seal wounds, binding the edges of the wound together using a biodegradable protein sealant or solder. This method could be used for repairing wounds in emergency settings by restoring the wound surface to its original strength within minutes. This technique could also be utilized for surgical purposes involving solid visceral organs (i.e., liver, spleen, and kidney) that currently do not respond well to ordinary surgical procedures. A miniaturized microwave generator and a handheld antenna are used to deliver microwave energy to the protein solder, which is applied to the wound. The antenna can be of several alternative designs optimized for placement either in contact with or in proximity to the protein solder covering the wound. In either case, optimization of the design includes the matching of impedances to maximize the energy delivered to the protein solder and wound at a chosen frequency. For certain applications, an antenna could be designed that would emit power only when it is in direct contact with the wound. The optimum frequency or frequencies for a specific application would depend on the required depth of penetration of the microwave energy. In fact, a computational simulation for each specific application could be performed, which would then match the characteristics of the antenna with the protein solder and tissue to best effect wound closure. An additional area of interest with potential benefit that remains to be validated is whether microwave energy can effectively kill bacteria in and around the wound. Thus, this may be an efficient method for simultaneously sterilizing and closing wounds.

  5. Preparation of solder pads by selective laser scanning

    Institute of Scientific and Technical Information of China (English)

    Wenqing Shi; Yongqiang Yang; Yanlu Huang; Guoqiang Wei; Wei Guo

    2009-01-01

    We propose a new laser preparation technique to solder Sn-Ag3.5-Cu0.7 on a copper clad laminate (CCL). The experiment is conducted by selective laser heating and melting the thin solder layer and then preprint-ing it on CCL in order to form the matrix with solder pads. Through the analysis of macro morphology of the matrix with solder pads and microstructure of single pads, this technique is proved to be suitable for preparing solder pads and that the solder pads are of good mechanical properties. The results also reveal that high frequency laser pulse is beneficial to the formation of better solder pad, and that the 12-W fiber laser with a beam diameter of 0.030 mm can solder Sn-Ag3.5-Cu0.7 successfully on CCL at 500-kHz pulse frequency. The optimized parameters of laser soldering on CCL are as follows: the laser power is 12 W, the scanning speed is 1.0 mm/s, the beam diameter is 0.030 mm, the lead-free solder is Sn-Ag3.5-Cu0.7, and the laser pulse frequency is 500 kHz.

  6. Effects of AlN Nanoparticles on the Microstructure, Solderability, and Mechanical Properties of Sn-Ag-Cu Solder

    Science.gov (United States)

    Jung, Do-Hyun; Sharma, Ashutosh; Lim, Dong-Uk; Yun, Jong-Hyun; Jung, Jae-Pil

    2017-09-01

    The addition of nanosized AlN particles to Sn-3.0 wt pctAg-0.5 wt pctCu (SAC305) lead-free solder alloy has been investigated. The various weight fractions of AlN (0, 0.03, 0.12, 0.21, 0.60 wt pct) have been dispersed in SAC305 solder matrix by a mechanical mixing and melting route. The influences of AlN nanosized particles on the microstructure, mechanical properties, and solderability ( e.g., spreadability and wettability) have been carried out. The structural and morphological features of the nanocomposite solder were characterized by scanning electron microscope (SEM), energy dispersive spectroscopy (EDS), and transmission electron microscope (TEM). The experimental results show that the best combination of solderability and mechanical properties is obtained at 0.21 wt pct AlN in the solder matrix. The reinforced composite solder with 0.21 wt pct AlN nanoparticles shows ≈25 pct improvement in ultimate tensile strength (UTS), and ≈4 pct increase in the spreadability. In addition, the results of microstructural analyses of composite solders indicate that the nanocomposite solder, especially reinforced with 0.21 wt pct of AlN nanoparticles, exhibits better microstructure and improved elongation percentage, compared with the monolithic SAC305 solder.

  7. Sn-Ag-Cu Nanosolders: Solder Joints Integrity and Strength

    Science.gov (United States)

    Roshanghias, Ali; Khatibi, Golta; Yakymovych, Andriy; Bernardi, Johannes; Ipser, Herbert

    2016-08-01

    Although considerable research has been dedicated to the synthesis and characterization of lead-free nanoparticle solder alloys, only very little has been reported on the reliability of the respective joints. In fact, the merit of nanoparticle solders with depressed melting temperatures close to the Sn-Pb eutectic temperature has always been challenged when compared with conventional solder joints, especially in terms of inferior solderability due to the oxide shell commonly present on the nanoparticles, as well as due to compatibility problems with common fluxing agents. Correspondingly, in the current study, Sn-Ag-Cu (SAC) nanoparticle alloys were combined with a proper fluxing vehicle to produce prototype nanosolder pastes. The reliability of the solder joints was successively investigated by means of electron microscopy and mechanical tests. As a result, the optimized condition for employing nanoparticles as a competent nanopaste and a novel procedure for surface treatment of the SAC nanoparticles to diminish the oxide shell prior to soldering are being proposed.

  8. Investigation of Solder Cracking Problems on Printed Circuit Boards

    Science.gov (United States)

    Berkebile, M. J.

    1967-01-01

    A Solder Committee designated to investigate a solder cracking phenomena occurring on the SATURN electrical/electronic hardware found the cause to be induced stress in the soldered connections rather than faulty soldering techniques. The design of the printed circuit (PC) board assemblies did not allow for thermal expansion of the boards that occurred during normal operation. The difference between the thermal expansion properties of the boards and component lead materials caused stress and cracking in the soldered connections. The failure mechanism and various PC boards component mounting configurations are examined in this report. Effective rework techniques using flanged tubelets, copper tubelets, and soft copper wiring are detailed. Future design considerations to provide adequate strain relief in mounting configurations are included to ensure successful solder terminations.

  9. Assessment of potential solder candidates for high temperature applications

    DEFF Research Database (Denmark)

    Multi-Chip module (MCM) technology is a specialized electronic packaging technology recently gaining momentum due to the miniaturization drive in the microelectronics industry. The step soldering approach is being employed in the MCM technology. This method is used to solder various levels...... of the package with different solders of different melting temperatures. High Pb containing alloys where the lead levels can be above 85% by weight, is one of the solders currently being used in this technology. Responding to market pressure i.e. need for green electronic products there is now an increasing...... 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...

  10. Anomalous creep in Sn-rich solder joints

    Energy Technology Data Exchange (ETDEWEB)

    Song, Ho Geon; Morris Jr., John W.; Hua, Fay

    2002-03-15

    This paper discusses the creep behavior of example Sn-rich solders that have become candidates for use in Pb-free solder joints. The specific solders discussed are Sn-3.5Ag, Sn-3Ag-0.5Cu, Sn-0.7Cu and Sn-10In-3.1Ag, used in thin joints between Cu and Ni-Au metallized pads.

  11. THERMAL PROCESS OF VACUUM FLUXLESS LASERSOLDERING AND ANALYSIS ON SOLDER SPREADING AND WETTING

    Institute of Scientific and Technical Information of China (English)

    2000-01-01

    In order to study the mechanism of vacuum fluxless soldering on the conditions of laser heating, the method of measuring temperature by the thermocouple is used to analyze the spreading and wetting process of boh fluxless SnPb solder in the vacuum surroundings and flux SnPb solder on Cu pad. Solder spreading and wetting affected by the soldering thermal process is also discussed according to the thermodynamics principle. Results show that vacuum fluxless soldering demands higher temperature, and the fall of the solder su rface tension is the important factor achieving fluxless laser soldering.

  12. Solderability preservation through the use of organic inhibitors

    Energy Technology Data Exchange (ETDEWEB)

    Sorensen, N.R.; Hosking, F.M.

    1994-12-01

    Organic inhibitors can be used to prevent corrosion of metals and have application in the electronics industry as solderability preservatives. We have developed a model to describe the action of two inhibitors (benzotriazole and imidazole) during the environmental aging and soldering process. The inhibitors bond with the metal surface and form a barrier that prevents or retards oxidation. At soldering temperatures, the metal-organic complex breaks down leaving an oxide-free metal surface that allows excellent wetting by molten solder. The presence of the inhibitor retards the wetting rate relative to clean copper, but provides a vast improvement relative to oxidized copper.

  13. Aging, stressing and solderability of electroplated and electroless copper

    Energy Technology Data Exchange (ETDEWEB)

    Sorensen, N.R.; Hosking, F.M.

    1995-08-01

    Organic inhibitors can be used to prevent corrosion of metals have application in the electronics industry as solderability preservatives. We have developed a model to describe the action of two inhibitors (benzotriazole and imidazole) during the environmental aging and soldering process. The inhibitors bond with the metal surface and form a barrier that prevents or retards oxidation. At soldering temperatures, the metal-organic complex breaks down leaving an oxide-free metal surface that allows excellent wetting by the molten solder. The presence of the inhibitor retards the wetting rate relative to clean copper but provides a vast improvement relative to oxidized copper.

  14. High temperature solder alloys for underhood applications: Final report

    Energy Technology Data Exchange (ETDEWEB)

    Kern, J.A. [Univ. of New Mexico, Albuquerque, NM (United States). Dept. of Mechanical Engineering; Drewien, C.A.; Yost, F.G.; Sackinger, S. [Sandia National Laboratories, Albuquerque, NM (United States); Weiser, M.W. [Johnson-Mathey Electronics Corp., Spokane, WA (United States)

    1996-06-01

    In this continued study, the microstructural evolution and peel strength as a function of thermal aging were evaluated for four Sn-Ag solders deposited on double layered Ag-Pt metallization. Additionally, activation energies for intermetallic growth over the temperature range of 134 to 190{degrees}C were obtained through thickness measurements of the Ag-Sn intermetallic that formed at the solder-metallization interface. It was found that Bi-containing solders yielded higher activation energies for the intermetallic growth, leading to thicker intermetallic layers at 175 and 190{degrees}C for times of 542 and 20.5 hrs, respectively, than the solders free of Bi. Complete reaction of the solder with the metallization occurred and lower peel strengths were measured on the Bi-containing solders. In all solder systems, a Ag-Sn intermetallic thickness of greater than {approximately}7 {mu}m contributed to lower peel strength values. The Ag-Sn binary eutectic composition and the Ag-Sn-Cu ternary eutectic composition solders yielded lower activation energies for intermetallic formation, less microstructural change with time, and higher peel strengths; these solder systems were resilient to the effects of temperatures up to 175{degrees}C. Accelerated isothermal aging studies provide useful criteria for recommendation of materials systems. The Sn-Ag and Sn-Ag-Cu eutectic compositions should be considered for future service life and reliability studies based upon their performance in this study.

  15. Recent Research Trend in Laser-Soldering Process

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Hwan Tae; Kil, Sang Cheol [Korea Institute of Science and Technology Information, Seoul (Korea, Republic of); Hwang, Woon Suk [Inha University, Incheon (Korea, Republic of)

    2009-10-15

    The trend of the microjoining technology by the laser-soldering process has been reviewed. Among the production technologies, joining technology plays an important role in the fabrication of electronic components. This has led to an increasing attention towards the use of modem microjoining technology such as micro-resistance spot joining micro-soldering, micro-friction stir joining and laser-soldering, etc. This review covers the recent technical trends of laser-soldering collected from the COMPENDEX DB analysis of published papers, research subject and research institutes.

  16. Efficacy of a new blister prevention plaster under tropical conditions.

    Science.gov (United States)

    Sian-Wei Tan, Shani; Kok, Swee Kuan; Lim, Jeremy Khim Yong

    2008-01-01

    To survey the incidence of blister formation in a group of military recruits and to determine the efficacy of a new commercially available blister prevention plaster (Blist-O-Ban). Questionnaires were completed by 100 male recruits, and the same 100 were entered into a field trial. Due to illness, 2 did not complete the study. Premarch foot condition was documented. Each participant acted as his own control. Foot side and plaster site were randomly selected, and plasters were applied according to a strict protocol. Participants were re-examined for blisters after a 16-km hike with pack, and the condition of the feet was documented. A chi2 test was used to analyze the results. Ninety-eight volunteers with 101 Blist-O-Ban application sites participated. Twenty-seven participants developed a total of 46 blisters. Heel and toe blisters accounted for more than half of all blisters. None of the bandage application sites developed blisters, and 99 out of 101 bandages remained well adhered to the application sites. When applied according to strict protocol, the new blister prevention bandage remained well-adhered to application sites and prevented the formation of foot blisters even in humid tropical conditions.

  17. The thermal analysis and derivative bronzes cast to plaster moulds

    Directory of Open Access Journals (Sweden)

    B. Pisarek

    2009-07-01

    Full Text Available It plaster moulds gets casted the alloys of following metals: Al, Cu, Ag, Au in precise and artistic founding. The investigation of the crys-tallization of bronzes in hot plaster moulds the method of the thermal analysis and derivative (TDA was not realized out so far. Probe TDAg and tripod enabling the execution of measurements on inductive casting machine INDUTHERM-VC 500D were designed for this technology especially. It was confirmed that one the method TDA can identify the crystallization process of the bronze in hot plaster moulds. The investigations of the superficial distribution of the concentration of elements in the microstructure of the studied grades of the bronze on X-ray microanalizer were conducted. It results that they be subject to in bronze CuSn10-C (B10 and the CuSn5Zn5Pb5-C (B555 of strong microsegregation from conducted investigations: Pb, Sn and Sb. The single separates of intermetallic phase κ was identified in the bronze B10 rich first of all in Zn, Sn, Sb and Fe, and two intermetallic phase, one rich were identified in the bronze B555 first of all in Zn, Sb, (Nor, Fe and second rich in Sn, Sb, (Nor, Fe. The most homogeneous microstructure from the bronze CuAl10Fe5Ni5-C (BA1055 is characterizes among the studied grades of the bronze in the cast state.

  18. 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.

  19. Effects of rare earth element Ce on solderabilities of micron-powdered Sn-Ag-Cu solder

    Institute of Scientific and Technical Information of China (English)

    XUE Song-bai; YU Sheng-lin; WANG Xu-yan; LIU lin; HU Yong-fang; YAO Li-hua

    2005-01-01

    Several important properties of the micron-powdered Sn-Ag-Cu-Ce solder, including the spreadability, spreading ratio, wetting time, and melting point, were investigated for verifying the effects of rare earth element Ce on solderabilities of micron-powdered Sn-Ag-Cu solder. The solidus and the liquidus of the micron-powdered Sn-Ag-Cu-Ce solder are 193.6℃ and 218.4℃, respectively, about 28℃ and 3℃ lower than the melting point of the block Sn-Ag-Cu solder, which reminds the existence of the surface effect of the micron-powdered solder. By adding Ce into Sn-Ag-Cu alloy, its wetting time on pure copper can be obviously decreased. For the Sn-Ag-Cu-0.03%Ce, the soldering temperature is 250℃, and the wetting time on pure copper is close to 1s, with the soldering temperature approaching to 260℃, the wetting time is dropped to 0.8s, which is close to the wetting time, 0.68s, of Sn-Pb solder at 235℃.

  20. A Study of the Interface of Soldered Joints of SnInAgTi Active Solder with Ito Ceramics

    Directory of Open Access Journals (Sweden)

    M. Provazník

    2010-01-01

    Full Text Available This paper presents an analysis of the solderability ITO ceramics (In2O3/SnO2. The soft active solder SnInAgeTi was used for the experiments. The solder was activated by power ultrasound in air without flux. An analysis of the interface of the phases between the solder and the ceramic was carried out in order to discover the ultrasonic impacts on the active metal and to identify the mechanism of the joint on the ceramic side.

  1. Calculation of k factor function for the carbonation process of lime-based plasters

    Science.gov (United States)

    Pavlíková, Milena; Pokorný, Jaroslav; Pavlík, Zbyšek

    2017-07-01

    The carbonation process of prepared lime plaster and lime based plaster with pozzolana active metakaolin is performed in an accelerated test arrangement. The depth of carbonation head is determined using colorimetric method and FTIR spectroscopy. Based on experimental data of carbonation head, time dependent k factor function is calculated that points to the decelerated and retarded propagation of the carbonation process due to metakaolin used in plaster composition.

  2. Possibility of reconstruction of dental plaster cast from 3D digital study models

    OpenAIRE

    Kasparova, Magdalena; Grafova, Lucie; Dvorak, Petr; Dostalova,Tatjana; Prochazka, Ales; Eliasova, Hana; Prusa, Josef; Kakawand, Soroush

    2013-01-01

    Objectives To compare traditional plaster casts, digital models and 3D printed copies of dental plaster casts based on various criteria. To determine whether 3D printed copies obtained using open source system RepRap can replace traditional plaster casts in dental practice. To compare and contrast the qualities of two possible 3D printing options – open source system RepRap and commercially available 3D printing. Design and settings A method comparison study on 10 dental plaster casts from th...

  3. Behavior of plasters on the modern heat-effective exterior walls of buildings (rus

    Directory of Open Access Journals (Sweden)

    Babkov V.V.

    2012-12-01

    Full Text Available Physical and mechanical characteristics, the most significant for the plasters with regard to the features of their behavior as the coating of building faces were evaluated. Results of quantitative estimation of stresses in the plaster layers on surfaces of different stiffness due to the plaster shrinkage are given. It is shown that with a decrease of the surface modulus of elasticity, stresses in the plaster coating are decreased either due to reduction of the effect of its deformations’ constraint. By analysis and with experiments it is proved, that the main factor evaluating the ultimate extensibility of the mortar is its viscoelasticity modulus, while mortar strength increase involves its stresses increase.

  4. Deformability of plastering compositions in design solutions of modern thermal protective exterior walls

    Directory of Open Access Journals (Sweden)

    R.R. Vakhitov

    2013-04-01

    Full Text Available In recent years, appearance of new constructive decisions for multilayer thermal efficient walls in the practice of design and construction caused the increasing use of protective and decorative plaster compositions. Comprehensive protective plaster systems nowadays are used in the facade insulation systems as a protective layer on the surface of polystyrene foam or mineral wool boards, forming the insulating layer to the outer walls of concrete blocks. They are also used for exterior finish of walls made of gas-concrete blocks, plastering the brickwork of the buildings operated by rehabilitation, in particular, apartment houses of old mass series. The problem of ensuring durability of thermal efficient external walls with the use of protective and decorative plaster systems were identified in this article. The factors, affecting the resistance of facade plasters to the action of external conditions in operating process were considered. The weaknesses in the necessary characteristics of plaster mixtures provided by material manufacturers are revealed. The existing methods for determining crack resistance of plaster compositions are monitored. The author's method of determining the maximum stretch of plaster compositions is given. The article presents tests results of various plaster compositions, confirming the effectiveness of the proposed method.

  5. Plaster of Paris-Short History of Casting and Injured Limb Immobilzation.

    Science.gov (United States)

    Szostakowski, B; Smitham, P; Khan, W S

    2017-01-01

    Various materials have been used since ancient times to help immobilise fractures. In this review, we discuss the history and developments of these materials as well as plaster of Paris. There has been a recent trend away from non-operative management of fractures, and skills in the use of plaster of Paris are declining. For the successful treatment of patients, it is important to appreciate how plaster works, how it should be used, and what can go wrong. In this review, we also discuss principles of applications and complications of plaster of Paris.

  6. Lidocaine/tetracaine medicated plaster: in minor dermatological and needle puncture procedures.

    Science.gov (United States)

    Croxtall, Jamie D

    2010-11-12

    The lidocaine/tetracaine medicated plaster comprises a lidocaine/tetracaine 70 mg/70 mg patch and a controlled heat-assisted drug delivery pod that increases the diffusion of lidocaine and tetracaine into the dermis. Following a 1-hour application period, systemic absorption of lidocaine or tetracaine from the plaster was minimal. The lidocaine/tetracaine medicated plaster provided effective pain relief for adult (including elderly) patients undergoing minor dermatological procedures and for adult and paediatric patients undergoing vascular access procedures. In randomized, double-blind clinical trials, patient-reported median pain scores were significantly lower with the lidocaine/tetracaine medicated plaster than with an identical plaster containing placebo in patients undergoing minor dermatological or vascular access procedures. Furthermore, patient-reported median pain scores were significantly lower with the lidocaine/tetracaine medicated plaster than with a lidocaine/prilocaine cream in patients undergoing vascular access procedures. In a large, randomized, double-blind trial in paediatric patients undergoing venipuncture, the overall incidence of pain was significantly lower with the lidocaine/tetracaine medicated plaster than with a lidocaine/prilocaine plaster. The lidocaine/tetracaine medicated plaster was well tolerated, with the most frequent treatment-related adverse events resolving spontaneously.

  7. Plaster of Paris–Short History of Casting and Injured Limb Immobilzation

    Science.gov (United States)

    Szostakowski, B.; Smitham, P.; Khan, W.S.

    2017-01-01

    Various materials have been used since ancient times to help immobilise fractures. In this review, we discuss the history and developments of these materials as well as plaster of Paris. There has been a recent trend away from non-operative management of fractures, and skills in the use of plaster of Paris are declining. For the successful treatment of patients, it is important to appreciate how plaster works, how it should be used, and what can go wrong. In this review, we also discuss principles of applications and complications of plaster of Paris. PMID:28567158

  8. Functional treatment versus plaster for simple elbow dislocations (FuncSiE: a randomized trial

    Directory of Open Access Journals (Sweden)

    Verleisdonk Egbert JMM

    2010-11-01

    Full Text Available Abstract Background Elbow dislocations can be classified as simple or complex. Simple dislocations are characterized by the absence of fractures, while complex dislocations are associated with fractures. After reduction of a simple dislocation, treatment options include immobilization in a static plaster for different periods of time or so-called functional treatment. Functional treatment is characterized by early active motion within the limits of pain with or without the use of a sling or hinged brace. Theoretically, functional treatment should prevent stiffness without introducing increased joint instability. The primary aim of this randomized controlled trial is to compare early functional treatment versus plaster immobilization following simple dislocations of the elbow. Methods/Design The design of the study will be a multicenter randomized controlled trial of 100 patients who have sustained a simple elbow dislocation. After reduction of the dislocation, patients are randomized between a pressure bandage for 5-7 days and early functional treatment or a plaster in 90 degrees flexion, neutral position for pro-supination for a period of three weeks. In the functional group, treatment is started with early active motion within the limits of pain. Function, pain, and radiographic recovery will be evaluated at regular intervals over the subsequent 12 months. The primary outcome measure is the Quick Disabilities of the Arm, Shoulder, and Hand score. The secondary outcome measures are the Mayo Elbow Performance Index, Oxford elbow score, pain level at both sides, range of motion of the elbow joint at both sides, rate of secondary interventions and complication rates in both groups (secondary dislocation, instability, relaxation, health-related quality of life (Short-Form 36 and EuroQol-5D, radiographic appearance of the elbow joint (degenerative changes and heterotopic ossifications, costs, and cost-effectiveness. Discussion The successful

  9. Surface tension and reactive wetting in solder connections

    Energy Technology Data Exchange (ETDEWEB)

    Wedi, Andre; Schmitz, Guido [Institut fuer Materialphysik, Westf. Wilhelms-Universitaet, Wilhelm-Klemm-Strasse 10, 48149 Muenster (Germany)

    2011-07-01

    Wetting is an important pre-requisite of a reliable solder connection. However, it is only an indirect measure for the important specific energy of the reactive interface between solder and base metallization. In order to quantify this energy, we measured wetting angles of solder drops as well as surface tension of SnPb solders under systematic variation of composition and gaseous flux at different reflow temperatures. For the latter, we used the sessile drop method placing a solder drop on a glas substrate. From the two independent data sets, the important energy of the reactive interface is evaluated based on Young's equation. Remarkably, although both, the tension between the solder and flux and the wetting angle, reveal significant dependence on solder composition. So the adhesion energy reveals distinguished plateaus which are related to different reaction products in contact to the solder. TEM analysis and calculations of phase stabilities show that there is no Cu6Sn5 for high lead concentrations. The experiments confirm a model of reactive wetting by Eustathopoulos.

  10. Assessment of potential solder candidates for high temperature applications

    DEFF Research Database (Denmark)

    of the package with different solders of different melting temperatures. High Pb containing alloys where the lead levels can be above 85% by weight, is one of the solders currently being used in this technology. Responding to market pressure i.e. need for green electronic products there is now an increasing...

  11. Cost comparison modeling between current solder sphere attachment technology and solder jetting technology

    Energy Technology Data Exchange (ETDEWEB)

    Davidson, R.N.

    1996-10-01

    By predicting the total life-cycle cost of owning and operating production equipment, it becomes possible for processors to make accurate and intelligent decisions regarding major capitol equipment investments as well as determining the most cost effective manufacturing processes and environments. Cost of Ownership (COO) is a decision making technique based on inputting the total costs of acquiring, operating and maintaining production equipment. All quantitative economic and production data can be modeled and processed using COO software programs such as the Cost of Ownership Luminator program TWO COOL{trademark}. This report investigated the Cost of Ownership differences between the current state-of-the-art solder ball attachment process and a prototype solder jetting process developed by Sandia National Laboratories. The prototype jetting process is a novel and unique approach to address the anticipated high rate ball grid array (BGA) production requirements currently forecasted for the next decade. The jetting process, which is both economically and environmentally attractive eliminates the solder sphere fabrication step, the solder flux application step as well as the furnace reflow and post cleaning operations.

  12. Possibility of reconstruction of dental plaster cast from 3D digital study models.

    Science.gov (United States)

    Kasparova, Magdalena; Grafova, Lucie; Dvorak, Petr; Dostalova, Tatjana; Prochazka, Ales; Eliasova, Hana; Prusa, Josef; Kakawand, Soroush

    2013-05-31

    To compare traditional plaster casts, digital models and 3D printed copies of dental plaster casts based on various criteria. To determine whether 3D printed copies obtained using open source system RepRap can replace traditional plaster casts in dental practice. To compare and contrast the qualities of two possible 3D printing options--source system RepRap and commercially available 3D printing. A method comparison study on 10 dental plaster casts from the Orthodontic department, Department of Stomatology, 2nd medical Faulty, Charles University Prague, Czech Republic. Each of 10 plaster casts were scanned by inEos Blue scanner and the printed on 3D printer RepRap [10 models] and ProJet HD3000 3D printer [1 model]. Linear measurements between selected points on the dental arches of upper and lower jaws on plaster casts and its 3D copy were recorded and statistically analyzed. 3D printed copies have many advantages over traditional plaster casts. The precision and accuracy of the RepRap 3D printed copies of plaster casts were confirmed based on the statistical analysis. Although the commercially available 3D printing enables to print more details than the RepRap system, it is expensive and for the purpose of clinical use can be replaced by the cheaper prints obtained from RepRap printed copies. Scanning of the traditional plaster casts to obtain a digital model offers a pragmatic approach. The scans can subsequently be used as a template to print the plaster casts as required. Using 3D printers can replace traditional plaster casts primarily due to their accuracy and price.

  13. A Study of Solder Alloy Ductility for Cryogenic Applications

    Science.gov (United States)

    Lupinacci, A.; Shapiro, A. A.; Suh, J-O.; Minor, A. M.

    2013-01-01

    For aerospace applications it is important to understand the mechanical performance of components at the extreme temperature conditions seen in service. For solder alloys used in microelectronics, cryogenic temperatures can prove problematic. At low temperatures Sn-based solders undergo a ductile to brittle transition that leads to brittle cracks, which can result in catastrophic failure of electronic components, assemblies and spacecraft payloads. As industrial processes begin to move away from Pb-Sn solder, it is even more critical to characterize the behavior of alternative Sn-based solders. Here we report on initial investigations using a modified Charpy test apparatus to characterize the ductile to brittle transformation temperature of nine different solder systems.

  14. Hybrid microcircuit board assembly with lead-free solders

    Energy Technology Data Exchange (ETDEWEB)

    Vianco, P.T.; Hernandez, C.L.; Rejent, J.A.

    2000-01-11

    An assessment was made of the manufacturability of hybrid microcircuit test vehicles assembled using three Pb-free solder compositions 96.5Sn--3.5Ag (wt.%), 91.84Sn--3.33Ag--4.83Bi, and 86.85Sn--3.15Ag--5.0Bi--5.0Au. The test vehicle substrate was 96% alumina; the thick film conductor composition was 76Au--21Pt--3Pd. Excellent registration between the LCCC or chip capacitor packages and the thick film solder pads was observed. Reduced wetting of bare (Au-coated) LCCC castellations was eliminated by hot solder dipping the I/Os prior to assembly of the circuit card. The Pb-free solders were slightly more susceptible to void formation, but not to a degree that would significantly impact joint functionality. Microstructural damage, while noted in the Sn-Pb solder joints, was not observed in the Pb-free interconnects.

  15. Current Status of Lead-Free Soldering and Conductive Adhesives

    Institute of Scientific and Technical Information of China (English)

    KatsuakiSuganuma

    2003-01-01

    Lead-free soldering technology took offin the Japanese market during the year 2000, and as the year 2001-03 ushered in the 21 st century, a large number of products with lead-free soldering were already appearing on store shelves. Elsewhere, EU deliberation on the draft of the WEEE/RoHS directive finalized in February 2003 and be in force in July 2006. The course had been set for adopting lead-free solder for mounting processes of parts as well, bringing the possibility of lead-free solder mounting very close to achievement. This review will provide a view of the current state of technological progress in lead-free soldering, both in Japan and abroad, and will discuss future prospects.

  16. Development of lead-free solders for hybrid microcircuits

    Energy Technology Data Exchange (ETDEWEB)

    Hosking, F.M.; Vianco, P.T.; Frear, D.R.; Robinson, D.G.

    1996-01-01

    Extensive work has been conducted by industry to develop lead-free solders for electronics applications. The driving force behind this effort is pressure to ban or tax the use of lead-bearing solders. There has been further interest to reduce the use of hazardous chemical cleaners. Lead-free soldering and low-residue, ``no clean`` assembly processing are being considered as solutions to these environmental issues. Most of the work has been directed toward commercial and military printed wiring board (PWB) technology, although similar problems confront the hybrid microcircuit (HMC) industry, where the development of lead-free HMC solders is generally lagging. Sandia National Laboratories is responsible for designing a variety of critical, high reliability hybrid components for radars. Sandia has consequently initiated a project, as part of its Environmentally Conscious Manufacturing program, to develop low-residue, lead-free soldering for HMCs. This paper discusses the progress of that work.

  17. PCM-enhanced lime plasters for vernacular and contemporary architecture

    Science.gov (United States)

    Theodoridou, Magdalini; Kyriakou, Loucas; Ioannou, Ioannis

    2016-04-01

    In 1997, the European Union (EU) pledged to reduce the amount of greenhouse gas emissions by 20% below the levels of 1990 by the end of 2020. In recent years it has become evident that, in order to reach that goal, EU Member States must take measures to encourage sustainability in the building industry, which is a major energy consumer. Such measures should involve the use of innovative, environmentally friendly materials and methods in new constructions, as well as the renovation of existing properties by upgrading their current state of energy efficiency. Phase Change Materials (PCMs) have the ability to absorb and release thermal energy, in the form of latent heat, during the melting or solidifying processes respectively. Thus, they may be used as additives in the production of thermally efficient composite building materials. A PCM-enhanced plaster is a heat storage medium combining an appropriate PCM with a cementitious or non-cementitious matrix to produce a low-cost thermal storage material with structural and thermostatic properties. Although innovative technologies, such as PCMs, have certainly contributed to the boost in the evolution of the building materials industry in recent years, a significant proportion of these technologies and practices have not yet been fully exploited in materials based on traditional principles. This paper focuses on the design and production of novel cementless PCM-enhanced lime plasters, in line with the traditional production technology of lime composites. The new plasters are produced using either hydrated or natural hydraulic lime binder, crushed calcarenite sand (0-2 mm) and commercial microencapsulated PCM in powder form (5% w/w of solids). Results from comparative tests between reference mixtures and mixtures with the addition of PCM, carried out 28, 56 and 90 days after laboratory production, prove the potential of PCMs in enhancing the thermal performance of traditional lime-based composites. The modified composites

  18. Effect of paint on vapour resistivity in plaster

    Directory of Open Access Journals (Sweden)

    de Villanueva, L.

    2008-12-01

    Full Text Available The vapour resistivity of plaster coatings such as paint and their effectiveness as water repellents were studied in several types of plaster. To this end, painted, unpainted and pigmented specimens were tested. Experimental values were collected on diffusion and vapour permeability, or its inverse, water vapour resistivity.The data obtained were very useful for evaluating moisture exchange between plaster and the surrounding air, both during initial drying and throughout the life of the material. They likewise served as a basis for ensuring the proper evacuation of water vapour in walls, and use of the capacity of the porous network in plaster products to regulate moisture content or serve as a water vapour barrier to avoid condensation.Briefly, the research showed that pigments, water-based paints and silicon-based water repellents scantly raised vapour resistance. Plastic paints, enamels and lacquers, however, respectively induced five-, ten- and twenty-fold increases in vapour resistivity, on average.Se estudia el fenómeno de la resistividad al vapor de los de yeso y el efecto impermeabilizante que producen los recubrimientos de pintura sobre diversos tipos de yeso y escayola. Para ello, se ensayan probetas desnudas y recubiertas con distintos tipos de pintura, así como coloreados en masa. Se obtienen valores experimentales de la difusividad o permeabilidad al vapor o su inverso la resistividad al vapor de agua.Los datos obtenidos son muy útiles para valorar el fenómeno del intercambio de humedad entre el yeso y el ambiente, tanto durante el proceso de su secado inicial, como en el transcurso de su vida. Así como para disponer soluciones adecuadas para la evacuación del vapor de agua a través de los cerramientos, para utilizar la capacidad de regulación de la humedad, que proporciona el entramado poroso de los productos de yeso, o para impedir el paso del vapor de agua y evitar condensaciones.Como resumen de la investigación, se

  19. PPF-reinforced, ESP-lightened gypsum plaster

    Directory of Open Access Journals (Sweden)

    García Santos, A.

    2009-03-01

    Full Text Available A new construction material has been obtained by adding aggregate to gypsum plaster which, without reducing the bending strength of plain gypsum plaster without aggregates, lowers its density, and consequently the weight of the construction elements made from the agglomerated material, by half.The aggregates used were expanded polystyrene beads and short polypropylene fibre.The new material addresses one of the issues of cardinal interest in construction materials and construction element research, namely the need to lighten materials so as to ease the burden on buildings’ bearing structures while facilitating assembly of construction units, by a single worker wherever possible.With a water / binder ratio of 0.7 and 2% (by weight of plaster of expanded polystyrene and 2% of polypropylene fibre aggregates, the decline in density achieved was 50,88% over plain gypsum plaster and 32.88% over plasterboard.Se ha obtenido un nuevo material de construcción aditivando el yeso o la escayola, mediante la incorporación de agregados, de modo que sin reducir la resistencia a flexotracción de una escayola sin ningún tipo de adición, reduce su densidad a la mitad, y por tanto, el peso de los elementos constructivos que puedan realizarse basándose en él.El material está compuesto por una adición de gránulos de poliestireno expandido y fibras cortadas de polipropileno.El nuevo material incide sobre aquellos aspectos de más interés en el campo de la investigación en construcción, en donde se intenta reducir el peso de los materiales, de modo que se grave lo menos posible la estructura resistente de las edificaciones, a la par que se facilitan los procedimientos de montaje de las unidades constructivas, al poder ser manejadas por un solo operario.La escayola, con relación de agua/conglomerante de 0,7, y con adiciones del 2% en peso (sobre la cantidad de escayola, tanto de poliestireno expandido como de fibras de polipropileno, permite reducir la

  20. Development of Biodegradable Nanosheets as Nano-adhesive Plasters

    Institute of Scientific and Technical Information of China (English)

    Shinji; Takeoka; Yosuke; Okamura; Toshinori; Fujie; Yoshihito; Fukui

    2007-01-01

    1 Results A nano-adhesive plaster is a biodegradable polymeric sheet with nanometer thickness; e.g.,one side is adhesive to a wound and the other side has high surface compatibility as biomaterial application.We proposed three kinds of polymeric nanosheets; the first is a sheet with ca.5 nm thickness made by cross-linking of human serum albumin (HSA) absorbed on a patterned octadecyltrimethoxysilane monolayer,the second is a nanosheet with ca.100 nm thickness prepared by thermal fusion of biodegradable P...

  1. Primers role in plastering systems on concrete surfaces

    Science.gov (United States)

    Fischer, H. B.

    2015-01-01

    A drastic reduction in time frames between the manufacturing process of concrete units and the rendering phase (including prior priming) does not allow the concrete to dry well. This fact is also underlined by changes in concrete technology (denser concrete and denser concrete surfaces). The tests showed that the reduction of drying time (storage time) had a significant influence on the bonding properties of gypsum plaster on concrete surfaces. In such cases it is absolutely necessary to use an appropriate primer no matter what the processing temperature (2 °C to 20 °C) might be. In this publication the varying primer quality is shown.

  2. The performance of a restoration plaster in the field: Investigation and monitoring of two case studies

    NARCIS (Netherlands)

    Lubelli, B.; Hees, R.P.J. van; Groot, C.J.W.P.

    2005-01-01

    A large number of restoration plasters, especially developed for salt loaded substrates, have been introduced on the market in the last decades. The performance of these plasters in the field is not always satisfactory. The reasons of the failures may be found in the severity of the exposure conditi

  3. Salt transport and crystallization in plaster layers: A nuclear magnetic resonance study

    NARCIS (Netherlands)

    Petkovic, J.; Pel, L.; Huinink, H.P.; Kopinga, K.; Hees, R.P.J. van

    2005-01-01

    The durability and performance of specially developed restoration plasters or renders, are not always as good as expected. Salt crystallization is one of the causes of the observed degradation processes. To understand these processes in more detail, we investigated whether transport in the plasters

  4. 3-D Wizardry: Design in Papier-Mache, Plaster, and Foam.

    Science.gov (United States)

    Wolfe, George

    Papier-mache, plaster, and foam are inexpensive and versatile media for 3-dimensional classroom and studio art experiences. They can be used equally well by elementary, high school, or college students. Each medium has its own characteristic. Papier-mache is pliable but dries into a hard, firm surface that can be waterproofed. Plaster can be…

  5. The performance of a restoration plaster in the field: Investigation and monitoring of two case studies

    NARCIS (Netherlands)

    Lubelli, B.; Hees, R.P.J. van; Groot, C.J.W.P.

    2005-01-01

    A large number of restoration plasters, especially developed for salt loaded substrates, have been introduced on the market in the last decades. The performance of these plasters in the field is not always satisfactory. The reasons of the failures may be found in the severity of the exposure conditi

  6. 3-D Wizardry: Design in Papier-Mache, Plaster, and Foam.

    Science.gov (United States)

    Wolfe, George

    Papier-mache, plaster, and foam are inexpensive and versatile media for 3-dimensional classroom and studio art experiences. They can be used equally well by elementary, high school, or college students. Each medium has its own characteristic. Papier-mache is pliable but dries into a hard, firm surface that can be waterproofed. Plaster can be…

  7. Duality Symmetry and Soldering in Different Dimensions

    CERN Document Server

    Banerjee, R

    1997-01-01

    We develop a systematic method of obtaining duality symmetric actions in different dimensions. This technique is applied for the quantum mechanical harmonic oscillator, the scalar field theory in two dimensions and the Maxwell theory in four dimensions. In all cases there are two such distinct actions. Furthermore, by soldering these distinct actions in any dimension a master action is obtained which is duality invariant under a much bigger set of symmetries than is usually envisaged. The concept of swapping duality is introduced and its implications are discussed. The effects of coupling to gravity are also elaborated. Finally, the extension of the analysis for arbitrary dimensions is indicated.

  8. Comparison of linear measurements and analyses taken from plaster models and three-dimensional images.

    Science.gov (United States)

    Porto, Betina Grehs; Porto, Thiago Soares; Silva, Monica Barros; Grehs, Renésio Armindo; Pinto, Ary dos Santos; Bhandi, Shilpa H; Tonetto, Mateus Rodrigues; Bandéca, Matheus Coelho; dos Santos-Pinto, Lourdes Aparecida Martins

    2014-11-01

    Digital models are an alternative for carrying out analyses and devising treatment plans in orthodontics. The objective of this study was to evaluate the accuracy and the reproducibility of measurements of tooth sizes, interdental distances and analyses of occlusion using plaster models and their digital images. Thirty pairs of plaster models were chosen at random, and the digital images of each plaster model were obtained using a laser scanner (3Shape R-700, 3Shape A/S). With the plaster models, the measurements were taken using a caliper (Mitutoyo Digimatic(®), Mitutoyo (UK) Ltd) and the MicroScribe (MS) 3DX (Immersion, San Jose, Calif). For the digital images, the measurement tools used were those from the O3d software (Widialabs, Brazil). The data obtained were compared statistically using the Dahlberg formula, analysis of variance and the Tukey test (p plaster models using the caliper and from the digital models using O3d software were identical.

  9. Early mobilisation versus plaster immobilisation of simple elbow dislocations: results of the FuncSiE multicentre randomised clinical trial.

    Science.gov (United States)

    Iordens, Gijs I T; Van Lieshout, Esther M M; Schep, Niels W L; De Haan, Jeroen; Tuinebreijer, Wim E; Eygendaal, Denise; Van Beeck, Ed; Patka, Peter; Verhofstad, Michael H J; Den Hartog, Dennis

    2017-03-01

    To compare outcome of early mobilisation and plaster immobilisation in patients with a simple elbow dislocation. We hypothesised that early mobilisation would result in earlier functional recovery. From August 2009 to September 2012, 100 adult patients with a simple elbow dislocation were enrolled in this multicentre randomised controlled trial. Patients were randomised to early mobilisation (n=48) or 3 weeks plaster immobilisation (n=52). Primary outcome measure was the Quick Disabilities of the Arm, Shoulder, and Hand (Quick-DASH) score. Secondary outcomes were the Oxford Elbow Score, Mayo Elbow Performance Index, pain, range of motion, complications and activity resumption. Patients were followed for 1 year. Quick-DASH scores at 1 year were 4.0 (95% CI 0.9 to 7.1) points in the early mobilisation group versus 4.2 (95% CI 1.2 to 7.2) in the plaster immobilisation group. At 6 weeks, early mobilised patients reported less disability (Quick-DASH 12 (95% CI 9 to 15) points vs 19 (95% CI 16 to 22); p<0.05) and had a larger arc of flexion and extension (121° (95% CI 115° to 127°) vs 102° (95% CI 96° to 108°); p<0.05). Patients returned to work sooner after early mobilisation (10 vs 18 days; p=0.020). Complications occurred in 12 patients; this was unrelated to treatment. No recurrent dislocations occurred. Early active mobilisation is a safe and effective treatment for simple elbow dislocations. Patients recovered faster and returned to work earlier without increasing the complication rate. No evidence was found supporting treatment benefit at 1 year. NTR 2025. Published by the BMJ Publishing Group Limited. For permission to use (where not already granted under a licence) please go to http://group.bmj.com/group/rights-licensing/permissions.

  10. Electromigration of composite Sn-Ag-Cu solder bumps

    Science.gov (United States)

    Sharma, Ashutosh; Xu, Di Erick; Chow, Jasper; Mayer, Michael; Sohn, Heung-Rak; Jung, Jae Pil

    2015-11-01

    This study investigates the electromigration (EM) behavior of lead free Sn-Ag-Cu (SAC) solder alloys that were reinforced with different types of nanoparticles [Copper-coated carbon nanotubes (Cu/CNT), La2O3, Graphene, SiC, and ZrO2]. The composite solders were bumped on a Cu substrate at 220°C, and the resistance of the bumped solders was measured using a four wire setup. Current aging was carried out for 4 hours at a temperature of 160°C, and an increase in resistance was noted during this time. Of all the composite solders that were studied, La2O3 and SiC reinforced SAC solders exhibited the smallest resistances after current aging. However, the rate of change in the resistance at room temperature was lower for the SiC-reinforced SAC solder. The SAC and Graphene reinforced SAC solder bumps completely failed within 15 - 20 min of these tests. The SiC nanoparticles were reported to possibly entrap the SAC atoms better than other nanoparticles with a lower rate of EM. [Figure not available: see fulltext.

  11. Environmentally compatible solder materials for thick film hybrid assemblies

    Energy Technology Data Exchange (ETDEWEB)

    Hosking, F.M.; Vianco, P.T.; Rejent, J.A.; Hernandez, C.L. [Sandia National Labs., Albuquerque, NM (United States). Materials and Process Sciences Center

    1997-02-01

    New soldering materials and processes have been developed over the last several years to address a variety of environmental issues. One of the primary efforts by the electronics industry has involved the development of alternative solders to replace the traditional lead-containing alloys. Sandia National Laboratories is developing such alternative solder materials for printed circuit board and hybrid microcircuit (HMC) applications. This paper describes the work associated with low residue, lead-free soldering of thick film HMC`s. The response of the different materials to wetting, aging, and mechanical test conditions was investigated. Hybrid test vehicles were designed and fabricated with a variety of chip capacitors and leadless ceramic chip carriers to conduct thermal, electrical continuity, and mechanical evaluations of prototype joints. Microstructural development along the solder and thick film interface, after isothermal solid state aging over a range of elevated temperatures and times, was quantified using microanalytical techniques. Flux residues on soldered samples were stressed (temperature-humidity aged) to identify potential corrosion problems. Mechanical tests also supported the development of a solder joint lifetime prediction model. Progress of this effort is summarized.

  12. Simulation of thermomechanical fatigue in solder joints

    Energy Technology Data Exchange (ETDEWEB)

    Fang, H.E.; Porter, V.L.; Fye, R.M.; Holm, E.A. [Sandia National Labs., Albuquerque, NM (United States)

    1997-12-31

    Thermomechanical fatigue (TMF) is a very complex phenomenon in electronic component systems and has been identified as one prominent degradation mechanism for surface mount solder joints in the stockpile. In order to precisely predict the TMF-related effects on the reliability of electronic components in weapons, a multi-level simulation methodology is being developed at Sandia National Laboratories. This methodology links simulation codes of continuum mechanics (JAS3D), microstructural mechanics (GLAD), and microstructural evolution (PARGRAIN) to treat the disparate length scales that exist between the macroscopic response of the component and the microstructural changes occurring in its constituent materials. JAS3D is used to predict strain/temperature distributions in the component due to environmental variable fluctuations. GLAD identifies damage initiation and accumulation in detail based on the spatial information provided by JAS3D. PARGRAIN simulates the changes of material microstructure, such as the heterogeneous coarsening in Sn-Pb solder, when the component`s service environment varies.

  13. Albumin-genipin solder for laser tissue welding

    Science.gov (United States)

    Lauto, Antonio; Foster, John; Avolio, Albert; Poole-Warren, Laura

    2004-07-01

    Background. Laser tissue soldering (LTS) is an alternative technique to suturing for tissue repair. One of the major drawbacks of LTS is the weak tensile strength of the solder welds when compared to sutures. In this study, the possibility was investigated for a low cytotoxic crosslinker, acting on amino groups, to enhance the bond strength of albumin solders. Materials and Methods. Solder strips were welded onto rectangular sections of sheep small intestine by a diode laser. The laser delivered in continuous mode mode a power of 170 +/- 10 mW at λ=808 nm, through a multimode optical fiber (core size = 200 μm) to achieve a dose of 10.8 +/- 0.5 J/mg. The solder thickness and surface area were kept constant throughout the experiment (thickness = 0.15 +/- 1 mm, area = 12 +/- 1.2 mm2). The solder incorporated 62% bovine serum albumin, 0.38% genipin, 0.25% indocyanin green dye (IG) and water. Tissue welding was also performed with a similar solder, which did not incorporate genipin, as a control group. The repaired tissue was tested for tensile strength by a calibrated tensiometer. Results. The tensile strength of the "genipin" solder was twice as high as the strength of the BSA solder (0.21 +/- 0.04 N and 0.11 +/- 0.04 N respectively; p~10-15 unpaired t-test, N=30). Discussion. Addition of a chemical crosslinking agent, such as genipin, significantly increased the tensile strength of adhesive-tissue bonds. A proposed mechanism for this enhanced bond strength is the synergistic action of mechanical adhesion with chemical crosslinking by genipin.

  14. Mechanical Reliability of Aged Lead-­Free Solders

    OpenAIRE

    Lewin, Susanne

    2012-01-01

    The usage of lead-­free solder joints in electronic packaging is of greatest concern to the electronic industry due to the health and environmental hazards arising with the use of lead. As a consequence, lead is legally prohibited in the European Union and the industry is aiming to produce lead-free products.            The reliability of solder joints is an important issue as the failure could destroy the whole function of a product. SnAgCu is a commonly used alloy for lead-­free solders. Co...

  15. Solder technology in the manufacturing of electronic products

    Energy Technology Data Exchange (ETDEWEB)

    Vianco, P.T.

    1993-08-01

    The electronics industry has relied heavily upon the use of soldering for both package construction and circuit assembly. The solder attachment of devices onto printed circuit boards and ceramic microcircuits has supported the high volume manufacturing processes responsible for low cost, high quality consumer products and military hardware. Defects incurred during the manufacturing process are minimized by the proper selection of solder alloys, substrate materials and process parameters. Prototyping efforts are then used to evaluate the manufacturability of the chosen material systems. Once manufacturing feasibility has been established, service reliability of the final product is evaluated through accelerated testing procedures.

  16. Theoretical preconditions for optimization of composition and technological parameters of the plaster for walls made of aerated concrete blocks (rus

    Directory of Open Access Journals (Sweden)

    Paruta V.A.

    2012-12-01

    Full Text Available The paper reveals the mechanism of cracking in the "aerated concrete masonry - plaster coating" system, which causes the reduction of cladding’s durability. The temperature deformations in the structure are analyzed. On this basis the theoretical background to optimize the composition and technological parameters of the plaster was developed. The composition of plaster mixtures based on the expanded clay, carbonate, perlite and other fillers was also developed. The proposition that targeted modification of plaster can ensure optimal operation of the "laying-plaster" system is experimentally confirmed.

  17. Solderability and intermetallic compounds formation of Sn-9Zn-xAg lead-free solders wetted on Cu substrate

    Institute of Scientific and Technical Information of China (English)

    CHEN Wenxue; XUE Songbai; WANG Hui; WANG Jianxin; HAN Zongjie

    2009-01-01

    The eutectie Sn-9Zn alloy was doped with Ag (0 wt.%-1 wt.%) to form Sn-9Zn-xAg lead-free solder alloys. The effect of the addition of Ag on the microstructure and solderability of this alloy was investigated and intermetallic compounds (IMCs) formed at the solder/Cu interface were also examined in this study. The results show that, due to the addition of Ag, the microstructure of the solder changes. When the quan-tity of Ag is lower than 0.3 wt.%, the needle-like Zn-rich phase decreases gradually. However, when the quantity of Ag is 0.5 wt.%-1 wt.%, Ag-Zn intermetallic compounds appear in the solder. In particular, adding 0.3 wt.% Ag improves the wetting behavior due to the better oxi-dation resistance of the Sn-9Zn solder. The addition of an excessive amount of Ag will deteriorate the wetting property because the gluti-nosity and fluidity of Sn-9Zn-(0.5, 1)Ag solder decrease. The results also indicate that the addition of Ag to the Sn-Zn solder leads to the pre-cipitation of ε-AgZn_3 from the liquid solder on preformed interracial intermetallics (Cu_5Zn_8). The peripheral AgZn_3, nodular on the Cu_5Zn_8 IMCs layer, is likely to be generated by a peritectic reaction L+γ-Ag_5Zn8→ε-AgZn_3 and the following crystallization of AgZn_3.

  18. 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.

  19. Thermophysical properties of hydrophobised lime plaster - Experimental analysis of moisture effect

    Science.gov (United States)

    Pavlíková, Milena; Pernicová, Radka; Pavlík, Zbyšek

    2016-07-01

    Lime plasters are the most popular finishing materials in renewal of historical buildings and culture monuments. Because of their limited durability, new materials and design solutions are investigated in order to improve plasters performance in harmful environmental conditions. For the practical use, the plasters mechanical resistivity and the compatibility with substrate are the most decisive material parameters. However, also plasters hygric and thermal parameters affecting the overall hygrothermal function of the renovated structures are of the particular importance. On this account, the effect of moisture content on the thermophysical properties of a newly designed lime plasters containing hydrophobic admixture is analysed in the paper. For the comparative purposes, the reference lime and cement-lime plasters are tested as well. Basic characterization of the tested materials is done using bulk density, matrix density, and porosity measurements. Thermal conductivity and volumetric heat capacity in the broad range of moisture content are experimentally accessed using a transient impulse method. The obtained data reveals the significant increase of the both studied thermal parameters with increasing moisture content and gives information on plasters behaviour in a highly humid environment and/or in the case of their possible direct contact with liquid water. The accessed material parameters will be stored in a material database, where can find use as an input data for computational modelling of coupled heat and moisture transport in this type of porous building materials.

  20. The topical 5% lidocaine medicated plaster in localized neuropathic pain: a reappraisal of the clinical evidence.

    Science.gov (United States)

    de León-Casasola, Oscar A; Mayoral, Victor

    2016-01-01

    Topical 5% lidocaine medicated plasters represent a well-established first-line option for the treatment of peripheral localized neuropathic pain (LNP). This review provides an updated overview of the clinical evidence (randomized, controlled, and open-label clinical studies, real-life daily clinical practice, and case series). The 5% lidocaine medicated plaster effectively provides pain relief in postherpetic neuralgia, and data from a large open-label controlled study indicate that the 5% lidocaine medicated plaster is as effective as systemic pregabalin in postherpetic neuralgia and painful diabetic polyneuropathy but with an improved tolerability profile. Additionally, improved analgesia and fewer side effects were experienced by patients treated synchronously with the 5% lidocaine medicated plaster, further demonstrating the value of multimodal analgesia in LNP. The 5% lidocaine medicated plaster provides continued benefit after long-term (≤7 years) use and is also effective in various other LNP conditions. Minor application-site reactions are the most common adverse events associated with the 5% lidocaine medicated plaster; there is minimal risk of systemic adverse events and drug-drug interactions. Although further well-controlled studies are warranted, the 5% lidocaine medicated plaster is efficacious and safe in LNP and may have particular clinical benefit in elderly and/or medically compromised patients because of the low incidence of adverse events.

  1. Evaluation of linear dimensional stability of various combinations of dental stone and plaster.

    Science.gov (United States)

    Adegbulugbe, I C; Oderinu, O H; Shaba, O P; Oremosu, O A

    2011-01-01

    It has been observed that due to the cheaper cost of dental plaster compared to dental stone, casts on which most of the dental prostheses and appliances were being fabricated in various laboratories were often mixtures of dental stone and dental plaster in order to reduce production cost. To evaluate the dimensional stability of various combinations of Dental Stone and Dental Plaster mixtures used to make dental casts. Alginate impressions of a master model of truncated metal cones were made and casts were produced by pouring with various combinations of dental stone and dental plaster mixtures. The linear dimensional differences between the inter-abutment distances on the casts were measured with an electronic caliper. One sample t-test and percentage differences were calculated. Dimensional variations for the distances measured using either 50% dental stone or 25% dental stone with plaster were statistically significant (p d" 0.05). Mixture of 75% dental stone and 25% dental plaster produced casts with no statistically significant dimensional variation from the master model (p e" 0.05). A mixture of 75% dental stone and 25% dental plaster could be used for procedures not requiring very accurate replica like mounting of teeth for dental training and for study models.

  2. Venous thromboembolism during hip plaster cast immobilisation: review of the literature.

    Science.gov (United States)

    Struijk-Mulder, M C; Ettema, H B; Heyne, R A J; Rondhuis, J J; Büller, H R; Verheyen, C C P M

    2014-01-01

    There is a paucity of data regarding the risk of deep vein thrombosis during hip plaster cast immobilisation. The purpose of this article was to review the available evidence regarding the incidence of symptomatic venous thromboembolism (VTE) during hip plaster cast immobilisation. All papers describing hip plaster cast immobilisation published in the English literature retrieved from PubMed, EMBASE and the Cochrane database were reviewed. Articles regarding children, hip dysplasia, congenital hip dislocation and Legg-Calvé-Perthes were excluded. A total of three papers were available for analysis. We also describe a case of pulmonary embolism during hip cast immobilisation. The overall incidence of symptomatic VTE during hip plaster cast immobilisation was 0% in 343 patients. The incidence of symptomatic VTE in hip cast brace was 2.3% (range 0-3%). Our systematic review of the literature showed a paucity of data regarding the incidence of VTE during hip plaster cast immobilisation. We describe the first case of pulmonary embolism during hip plaster cast immobilisation. We recommend that patients who are fitted with a hip plaster cast should be routinely screened for additional risk factors. When risk factors are present, patients should be considered for pharmacological thromboprophylaxis.

  3. [Acupuncture combined with moxibustion plaster for nerve-root type cervical spondylosis].

    Science.gov (United States)

    Liu, Li-an; Zhang, Shu; Wang, Hajying; Tang Lixin

    2016-02-01

    To compare the clinical efficacy differences between acupuncture combined with moxi-bustion plaster and electroacupuncture (EA) for nerve-root type cervical spondylosis. A total of 60 casesof nerve-root type cervical spondylosis were randomly divided into a plaster group and an EA group, 30 cases ineach one. Patients in the plaster group were treated with regular acupuncture at Jiaji(EX-B 2) points and ashipoints, combined with moxibustion plaster at Gaohuang (BL 43); patients in the EA group were treated with EAat identical acupoints as plaster group. The treatment was given once a day, and 5 days were taken as one course;there was an interval of 2 days between courses and totally 2 courses were performed. The pain questionnaires andquantitative score of signs and symptoms were observed before and after treatment in the two groups. The clinicalefficacy of the two groups was compared. The total effective rate was 96. 7% (29/30) in the plastergroup, which was not significantly different from 93. 3% (28/30) in the EA group (P>0. 05). After treatment,PRI, VAS and PPI were all reduced in the two groups (all Pplaster groups (all Pplaster group (all Pplaster and EA both have superior clinical efficacy for nerve-root type cervical spondylosis; EA issuperior to acupuncture combined with moxibustion plaster on relieving pain, while acupuncture combined withmoxibustion plaster is superior to EA on improving life quality, muscle strength and feeling.

  4. Accuracy of laser-scanned models compared to plaster models and cone-beam computed tomography.

    Science.gov (United States)

    Kim, Jooseong; Heo, Giseon; Lagravère, Manuel O

    2014-05-01

    To compare the accuracy of measurements obtained from the three-dimensional (3D) laser scans to those taken from the cone-beam computed tomography (CBCT) scans and those obtained from plaster models. Eighteen different measurements, encompassing mesiodistal width of teeth and both maxillary and mandibular arch length and width, were selected using various landmarks. CBCT scans and plaster models were prepared from 60 patients. Plaster models were scanned using the Ortho Insight 3D laser scanner, and the selected landmarks were measured using its software. CBCT scans were imported and analyzed using the Avizo software, and the 26 landmarks corresponding to the selected measurements were located and recorded. The plaster models were also measured using a digital caliper. Descriptive statistics and intraclass correlation coefficient (ICC) were used to analyze the data. The ICC result showed that the values obtained by the three different methods were highly correlated in all measurements, all having correlations>0.808. When checking the differences between values and methods, the largest mean difference found was 0.59 mm±0.38 mm. In conclusion, plaster models, CBCT models, and laser-scanned models are three different diagnostic records, each with its own advantages and disadvantages. The present results showed that the laser-scanned models are highly accurate to plaster models and CBCT scans. This gives general clinicians an alternative to take into consideration the advantages of laser-scanned models over plaster models and CBCT reconstructions.

  5. High temperature solder alloys for underhood applications. Progress report

    Energy Technology Data Exchange (ETDEWEB)

    Drewien, C.A.; Yost, F.G.; Sackinger, S. [Sandia National Labs., Albuquerque, NM (United States); Kern, J.; Weiser, M.W. [Univ. of New Mexico (United States). Dept. of Mechanical Engineering

    1995-02-01

    Under a cooperative research and development agreement with General Motors Corporation, lead-free solder systems including the flux, metallization, and solder are being developed for high temperature, underhood applications. Six tin-rich solders, five silver-rich metallizations, and four fluxes were screened using an experimental matrix whereby every combination was used to make sessile drops via hot plate or Heller oven processing. The contact angle, sessile drop appearance, and in some instances the microstructure was evaluated to determine combinations that would yield contact angles of less than 30{degrees}, well-formed sessile drops, and fine, uniform microstructures. Four solders, one metallization, and one flux were selected and will be used for further aging and mechanical property studies.

  6. Influence of Conditions of Preparing the Foamed Plaster on its Degree of Foaming

    Directory of Open Access Journals (Sweden)

    M. Pawlak

    2007-07-01

    Full Text Available Foamed plaster moulds are used in precision casting process of non-ferrous alloys. Casting from those moulds are characterizedby high dimensional accuracy, very good shape pattering and small surface roughness. However, a drawback of the plaster mould is very low permeability. A substational improvement of this parametr may be achived through physical or phisico-chemical treatment of the plaster slurry or prepared mould. The most advantageous results can be obtained by foaming the slurry. The investigatious comprised evaluation of the influence of mixing parametrs (mixer type, rotation and mixing time, settings the mixer in mixing device and the content of a foaming agent on the degree of foaming of the plaster. The tests were carried out using the α-plaster Hartform-H1 and Alkanol XC as a foaming agent. The structure of a slurry produced after foaming is non-homogeous. Therefore, the investigations were completed by making appropriate of this process. Analysis of the results leads to the conclusion, that the foamed plaster Hartform_H1 reaches the top degree of foaming at the following parameters: the water/plaster ratio W/G=0.55, the content of Alkanol XC a=0.07%, stirring with a perforate disc mixer at the rotation speed nm=4000 rpm during τm=30 s. In turn the top homogeneity of the foamed plaster slurry can be achieved at the rotation speed nu=1400 rpm during τu=30 s., while other parameters are the same as in the foaming process. The obtained results can provide the basis for the elaboration of the industry procedures useful in the production of the plaster moulds for precision casting.

  7. 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 for inte......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...

  8. Method of defence of solder surface from oxidization

    Directory of Open Access Journals (Sweden)

    Kurmashev Sh. D.

    2010-02-01

    Full Text Available Compositions are developed for defence of fusion solder from oxidization on the basis of mixture of glycerin, urea and powders of refractory oxides, carbides (Al2O3, TiO2, SIC, graphite. The offered compositions can be used for defence of fusion of solder from oxidization in the process of soludering and tinning of explorers, and also electric conclusions of elements of radio electronic apparatus by the method of immersion in stationary baths.

  9. OBSERVATION ON THE THERAPEUTIC EFFECT OF AURICULAR PLASTER FOR TREATMENT OF 135 CASES OF MOTION SICKNESS

    Institute of Scientific and Technical Information of China (English)

    RAO Zhongdong; WEN Ming; HU Yuehua

    2002-01-01

    In the present paper, the therapeutic effects of auricular plaster (otopoint-pellet pressing therapy)and Western medicine (Dramamine) were compared in the treatment of 200 cases of motion sickness who were randomly divided into auricular plaster group (n = 135) and Western medicine (control) group (n = 65). Results indicated that the markedly effective rates and total effective rates of auricular plaster group and control group were 51. 1% and 23. 1 %, 94.1% and 81.6% respectively, and the therapeutic effect of the former group was significantly superior to that of the control group (P<0.01).

  10. Influence of the input parameters on the efficiency of plaster sanding with alundum abrasive discs

    Science.gov (United States)

    Krajcarz, D.; Spadło, S.; Młynarczyk, P.

    2017-02-01

    The paper presents test results concerning the relationship between selected input parameters and the process efficiency for the sanding of plaster surfaces with alundum abrasive discs. The input parameters under study were the size of the abrasive grains, the force exerted by the plaster sample pressing against the abrasive disc and the no-load rotational speed of the abrasive disc. The experimental data illustrating the relationship between the process efficiency and the particular input parameters were used to select the optimum plaster sanding conditions.

  11. Critical evaluations of lead-free solder alloys and performance comparisons

    Energy Technology Data Exchange (ETDEWEB)

    Hitch, T.T.; Palit, K.; Prabhu, A.N. [David Sarnoff Research Center, Princeton, NJ (United States)

    1996-12-31

    This paper discusses the methodology for solder alloy selection, solder preparation processes, test selection, results, and conclusions. The conclusions from this phase of study were that: (1). Solders containing significant amounts of bismuth exhibit poor fatigue life. (2). The Sn-Ag-Cu alloy was the best solder we studied for use as a replacement for Sn-Pb eutectic. A second phase of the work involved detailed study of the Sn-Ag-Cu system with other additions to determine the optimum lead-free solder compositions in terms of melting point, solderability, and mechanical properties.

  12. Interfacial Reaction of Sn-Ag-Cu Lead-Free Solder Alloy on Cu: A Review

    OpenAIRE

    Liu Mei Lee; Ahmad Azmin Mohamad

    2013-01-01

    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 disc...

  13. New Plaster Composite with Mineral Wool Fibres from CDW Recycling

    Directory of Open Access Journals (Sweden)

    Sonia Romaniega Piñeiro

    2015-01-01

    Full Text Available Over the last decade the intense activity of the building sector has generated large quantities of construction and demolition waste (CDW. In particular, in Europe around 890 million tons of CDW is generated every year; however, only 50% of them are recycled. In Spain, over the last years 40 millions of tons of construction and demolition waste have been generated. On the other hand, since the implementation of the Technical Building Code regulation the use of mineral wools as building insulation materials has become a widespread solution in both rehabilitation and new construction works, and because of that, this kind of insulation waste is increasing. This research analyzes the potential of a new composite (gypsum and fiber waste including several mineral wools waste into a plaster matrix. For this purpose, an experimental plan, characterizing the physical and mechanical behaviour as well as the Shore C hardness of the new composite, was elaborated fulfilling UNE Standards.

  14. Microsurgical anastomosis of sperm duct by laser tissue soldering

    Science.gov (United States)

    Wehner, Martin M.; Teutu-Kengne, Alain-Fleury; Brkovic, Drasko; Henning, Thomas; Klee, Doris; Poprawe, Reinhart; Jakse, Gerhard

    2005-04-01

    Connection of small vessels is usually done by suturing which is very cumbersome. Laser tissue soldering can circumvent that obstacle if a handy procedure can be defined. Our principle approach consists of a bioresorbable hollow stent with an expected degradation time of 3 weeks in combination with laser soldering. The stent is to be fed into the vessel to stabilize both ends and should allow percolation immediately after joining. The stents are made of Poly(D,L-lactid-co-glycolid) and solder is prepared from bovine serum albumin (BSA) doped with Indocyanine green (ICG) as chromophore to increase the absorption of laser light. After insertion, solder is applied onto the outer surface of the vessel and coagulated by laser radiation. The wavelength of 810 nm of a diode laser fits favorably to absorption properties of tissue and solder such that heating up of tissue is limited to prevent from necrosis and wound healing complications. In our study the preparation of stents, the consistency and doping of solder, a beam delivery instrument and the irradiation conditions are worked out. In-vitro tests are carried out on sperm ducts of Sprague-Dowlae (SD) rats. Different irradiation conditions are investigated and a micro-optical system consisting of a lens and a reflecting prism to ensure simultaneous irradiation of front and back side of the vessels tested. Under these conditions, the short-term rupture strength of laser anastomosis revealed as high as those achieved by suturing.

  15. 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.

  16. Creep properties of Pb-free solder joints

    Energy Technology Data Exchange (ETDEWEB)

    Song, H.G.; Morris Jr., J.W.; Hua, F.

    2002-04-01

    Describes the creep behavior of three Sn-rich solders that have become candidates for use in Pb-free solder joints: Sn-3.5Ag, Sn-3Ag-0.5Cu and Sn-0.7Cu. The three solders show the same general behavior when tested in thin joints between Cu and Ni/Au metallized pads at temperatures between 60 and 130 C. Their steady-state creep rates are separated into two regimes with different stress exponents(n). The low-stress exponents range from {approx}3-6, while the high-stress exponents are anomalously high (7-12). Strikingly, the high-stress exponent has a strong temperature dependence near room temperature, increasing significantly as the temperature drops from 95 to 60 C. The anomalous creep behavior of the solders appears to be due to the dominant Sn constituent. Joints of pure Sn have stress exponents, n, that change with stress and temperature almost exactly like those of the Sn-rich solder joints. Research on creep in bulk samples of pure Sn suggests that the anomalous temperature dependence of the stress exponent may show a change in the dominant mechanism of creep. Whatever its source, it has the consequence that conventional constitutive relations for steady-state creep must be used with caution in treating Sn-rich solder joints, and qualification tests that are intended to verify performance should be carefully designed.

  17. Solderability perservative coatings: Electroless tin vs. organic azoles

    Energy Technology Data Exchange (ETDEWEB)

    Artaki, I.; Ray, U.; Jackson, A.M.; Gordon, H.M. [AT and T Bell Labs., Princeton, NJ (United States); Vianco, P.T. [Sandia National Labs., Albuquerque, NM (United States)

    1993-07-01

    This paper compares the solderability performance and corrosions ion protection effectiveness of electroless tin coatings versus organic azole films after exposure to a series of humidity and thermal (lead-free solders) cycling conditions. The solderability of immersion tin is directly related to the tin oxide growth on the surface and is not affected by the formation of Sn-Cu intermetallic phases as long as the intermetallic phase is protected by a Sn layer. For a nominal tin thickness of 60{mu}inches, the typical thermal excursions associated with assembly are not sufficient to cause the intermetallic phase to consume the entire tin layer. Exposure to humidity at moderate to elevated temperatures promotes heavy tin oxide formation which leads to solderability loss. In contrast, thin azole films are more robust to humidity exposure; however upon heating in the presence of oxygen, they decompose and lead to severe solderability degradation. Evaluations of lead-free solder pastes for surface mount assembly applications indicate that immersion tin significantly improves the spreading of Sn:Ag and Sn:Bi alloys as compared to azole surface finishes.

  18. Soldering in prosthodontics--an overview, part I.

    Science.gov (United States)

    Byrne, Gerard

    2011-04-01

    The fit of fixed multiunit dental prostheses (FDP), traditionally termed fixed partial dentures (FPDs), is an ongoing problem. Poorly fitting restorations may hasten mechanical failure, due to abutment caries or screw failure. Soldering and welding play an important role in trying to overcome misfit of fixed multiunit prostheses. The term FPD will be used to denote multiunit fixed dental prostheses in this review. This is the first of a series of articles that review the state of the art and science of soldering and welding in relation to the fit of cemented or screw-retained multiunit prostheses. A comprehensive archive of background information and scientific findings is presented. Texts in dental materials and prosthodontics were reviewed. Scientific data were drawn from the numerous laboratory studies up to and including 2009. The background, theory, terminology, and working principles, along with the applied research, are presented. This first article focuses on soldering principles and dimensional accuracy in soldering. There is some discussion and suggestions for future research and development. Soldering may improve dimensional accuracy or reduce the distortion of multiunit fixed prostheses. Many variables can affect the outcome in soldering technique. Research science has developed some helpful guidelines. Research projects are disconnected and limited in scope. © 2011 by The American College of Prosthodontists.

  19. Soldering of Thin Film-Metallized Glass Substrates

    Energy Technology Data Exchange (ETDEWEB)

    Hosking, F.M.; Hernandez, C.L.; Glass, S.J.

    1999-03-31

    The ability to produce reliable electrical and structural interconnections between glass and metals by soldering was investigated. Soldering generally requires premetallization of the glass. As a solderable surface finish over soda-lime-silicate glass, two thin films coatings, Cr-Pd-Au and NiCr-Sn, were evaluated. Solder nettability and joint strengths were determined. Test samples were processed with Sn60-Pb40 solder alloy at a reflow temperature of 210 C. Glass-to-cold rolled steel single lap samples yielded an average shear strength of 12 MPa. Solder fill was good. Control of the Au thickness was critical in minimizing the formation of AuSn{sub 4} intermetallic in the joint, with a resulting joint shear strength of 15 MPa. Similar glass-to-glass specimens with the Cr-Pd-Au finish failed at 16.5 MPa. The NiCr-Sn thin film gave even higher shear strengths of 20-22.5 MPa, with failures primarily in the glass.

  20. 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

  1. Characterization of Low-Melting-Point Sn-Bi-In Lead-Free Solders

    Science.gov (United States)

    Li, Qin; Ma, Ninshu; Lei, YongPing; Lin, Jian; Fu, HanGuang; Gu, Jian

    2016-11-01

    Development of lead-free solders with low melting temperature is important for substitution of Pb-based solders to reduce direct risks to human health and the environment. In the present work, Sn-Bi-In solders were studied for different ratios of Bi and Sn to obtain solders with low melting temperature. The microstructure, thermal properties, wettability, mechanical properties, and reliability of joints with Cu have been investigated. The results show that the microstructures of the Sn-Bi-In solders were composed of β-Sn, Bi, and InBi phases. The intermetallic compound (IMC) layer was mainly composed of Cu6Sn5, and its thickness increased slightly as the Bi content was increased. The melting temperature of the solders was around 100°C to 104°C. However, when the Sn content exceeded 50 wt.%, the melting range became larger and the wettability became worse. The tensile strength of the solder alloys and solder joints declined with increasing Bi content. Two fracture modes (IMC layer fracture and solder/IMC mixed fracture) were found in solder joints. The fracture mechanism of solder joints was brittle fracture. In addition, cleavage steps on the fracture surface and coarse grains in the fracture structure were comparatively apparent for higher Bi content, resulting in decreased elongation for both solder alloys and solder joints.

  2. Influences of fine pitch solder joint shape parameters on fatigue life under thermal cycle

    Institute of Scientific and Technical Information of China (English)

    HUANG Chun-yue; WU Zhao-hua; HUANG Hong-yan; ZHOU De-jian

    2005-01-01

    The solder joint reliability of a 0. 5 mm lead pitch, 240-pin quad flat package(QFP) was studied by nonlinear finite element analysis(FEA). The stress/strain distributions within the solder joints and the maximum plastic strain range of the solder joints were determined. Based on the calculated maximum plastic strain range the thermal fatigue life of the solder joints was calculated using Coffin-Manson equation. The influences of shape parameters including volume of solder joint, pad size and stand-off on the thermal fatigue life of the solder joints were also studied. The results show that the stress and strain distribution in the solder joint are not uniform; the interface between the lead and the solder joint is the high stress and strain region; the maximum stress and stain occur at the topmost point where the solder joint intersects with the inner side of the lead. The solder joint cracks should occur firstly at this point and propagate along the interface between the solder and the lead. The solder joint with the pad size of 1.25 mm× 0.35 mm, the stand-off of 0.02 mm and the solder volume of 0. 026 mm3 has longer fatigue life than that of any others. These optimal parameters have been applied in practice to assemble the 240-pin, 0.5 mm pitch QFP.

  3. Solderability of Sn-9Zn-0.5Ag-1In lead-free solder on Cu substrate

    Energy Technology Data Exchange (ETDEWEB)

    Chang, T.-C. [Department of Materials Science and Engineering, National Cheng Kung University, 1 Ta-Hsueh Road, Tainan 70101, Taiwan (China); Wang, J.-W. [Department of Environmental and Safety Engineering, Chung Hwa College of Medical Technology, 89 Wen-Hwa 1st Street, Jen-Te, Tainan 71703, Taiwan (China); Wang, M.-C. [Department of Mechanical Engineering, National Kaohsiung University of Applied Sciences, 415 Chien-Kung Road, Kaohsiung 80782, Taiwan (China)]. E-mail: mcwang@cc.kuas.edu.tw; Hon, M.-H. [Department of Materials Science and Engineering, National Cheng Kung University, 1 Ta-Hsueh Road, Tainan 70101, Taiwan (China); Da-Yeh University, 112 Shan Jean Road, Da-tsuen, Chang-hua, Taiwan (China)

    2006-09-28

    The thermal properties, microstructure corrosion and oxidation resistance of the Sn-9Zn-0.5Ag-1In lead-free solder have been investigated by differential scanning calorimetry, X-ray diffractometry, scanning electron microscopy, energy dispersive spectrometry, potentiostat and thermogravimetry. The Sn-9Zn-0.5Ag-1In solder alloy has a near-eutectic composition, it melts at 187.6 deg. C and the heat of fusion is determined as 71.3 J/g. The Sn-9Zn-0.5Ag-1In solder alloy with a corrosion potential of -1.09 V{sub SCE} and a current density of 9.90 x 10{sup -2} A/cm{sup 2}, shows a better corrosion resistance than that of the Sn-9Zn solder alloy. From the thermogravimetry analysis, the weight gain ratio of the Sn-9Zn solder alloy appears a parabolic relationship at 150 deg. C. The initial oxidation behavior of the Sn-9Zn-0.5Ag and Sn-9Zn-0.5Ag-1In solder alloys also shows a parabolic relationship but the weight gain ratio of them appears a negative linear one after aging at 150 deg. C for 2.5 and 5 h, respectively.

  4. Characterization of a lime-pozzolan plaster containing phase change material

    Energy Technology Data Exchange (ETDEWEB)

    Pavlíková, Milena; Pavlík, Zbyšek; Trník, Anton; Pokorný, Jaroslav; Černý, Robert [Department of Materials Engineering and Chemistry, Faculty of Civil Engineering, Czech Technical University in Prague, Thákurova 7, 166 29 Prague (Czech Republic)

    2015-03-10

    A PCM (Phase Change Material) modified lime-pozzolan plaster for improvement of thermal energy storage of building envelopes is studied in the paper. The investigated plaster is composed of lime hydrate, pozzolan admixture based on metakaolin and mudstone, silica sand, water and paraffin wax encapsulated in polymer capsule. The reference plaster without PCM application is studied as well. The analyzed materials are characterized by bulk density, matrix density, total open porosity, compressive strength and pore size distribution. The temperature of phase change, heat of fusion and crystallization are studied using DSC (Difference Scanning Calorimetry) analysis performed in air atmosphere. In order to get information on materials hygrothermal performance, determination of thermal and hygric properties is done in laboratory conditions. Experimental data reveal a substantial improvement of heat storage capacity of PCM-modified plaster as compared to the reference material without PCM.

  5. Reliability and validity of measurements on digital study models and plaster models.

    Science.gov (United States)

    Reuschl, Ralph Philip; Heuer, Wieland; Stiesch, Meike; Wenzel, Daniela; Dittmer, Marc Philipp

    2016-02-01

    To compare manual plaster cast and digitized model analysis for accuracy and efficiency. Nineteen plaster models of orthodontic patients in permanent dentition were analyzed by two calibrated examiners. Analyses were performed with a diagnostic calliper and computer-assisted analysis after digitization of the plaster models. The reliability and efficiency of different examiners and methods were compared statistically using a mixed model. Statistically significant differences were found for comparisons of all 28 teeth (P plaster model analysis appears to be an adequate, reliable, and time saving alternative to analogue model analysis using a calliper. © The Author 2015. Published by Oxford University Press on behalf of the European Orthodontic Society. All rights reserved. For permissions, please email: journals.permissions@oup.com.

  6. Topical pain management with the 5% lidocaine medicated plaster--a review.

    Science.gov (United States)

    Mick, Gérard; Correa-Illanes, Gerardo

    2012-06-01

    The topical 5% lidocaine medicated plaster is recommended as first-line treatment for localized peripheral neuropathic pain. In order to provide an overview of the efficacy and safety of the lidocaine plaster in the treatment of different neuropathic pain conditions, all efficacy and safety studies (randomized, controlled, or open-label with well described methodology), case reports, and pharmacological studies on the lidocaine plaster retrieved from a PubMed literature research (1960-March 2012) plus additional references identified from retrieved articles were included. The lidocaine plaster is efficacious in the treatment of neuropathic pain symptoms associated with previous herpes zoster infection. Results from a large open-label controlled study suggest that the lidocaine plaster could be at least as effective as systemic pregabalin in the treatment of postherpetic neuralgia and painful diabetic polyneuropathy. Open-label studies indicate efficacy in the treatment of other localized neuropathic pain conditions, such as painful idiopathic sensory polyneuropathy, complex regional pain syndrome, carpal tunnel syndrome sequelae, postsurgical and posttraumatic pain. Quality of life markedly improved in a variety of neuropathic pain conditions and long-term treatment provided sustained relief in patients with neuropathic pain who are responsive to lidocaine plaster. The lidocaine plaster is usually well tolerated. The risk of systemic adverse events and pharmacokinetic interactions with concomitant medication is minimal owing to low systemic exposure. Treatment of several, primarily neuropathic and mixed-pain conditions with the 5% lidocaine medicated plaster was found efficacious and safe. Further controlled studies, in particular where only small open-label studies or case reports are available, should be considered.

  7. Long-term treatment of neuropathic pain with a 5% lidocaine medicated plaster.

    Science.gov (United States)

    Wilhelm, Ilca Ricarda; Tzabazis, Alexander; Likar, Rudolf; Sittl, Reinhard; Griessinger, Norbert

    2010-02-01

    The 5% lidocaine medicated plaster is a topical treatment for peripheral neuropathic pain symptoms (e.g. burning, shooting and stabbing pain) and is registered for the treatment of postherpetic neuralgia. This study examined the efficacy and tolerability of long-term treatment with the 5% lidocaine medicated plaster in patients with localized neuropathic pain conditions. Twenty patients with localized neuropathic pain [postoperative neuropathic pain (n = 14); complex regional pain syndrome (n = 2); and postherpetic neuralgia (n = 4)], who had been successfully treated with 5% lidocaine medicated plaster, were followed up by telephone interview after 3 and 5 years. Questions were related to the efficacy, development of tolerance, tolerability, wear time and comfort of the plaster. At 3 years, 10 out of 20 (50%) initial responders were still using the plasters with no decline in analgesic efficacy. After 5 years, eight of the original 20 responders (40%) maintained treatment and continued to experience effective pain relief. The 12 responders who discontinued treatment did so because they no longer required analgesic therapy (n = 4); their health insurer refused to fund treatment (n = 2); they were lost to follow-up (n = 1); or had died from an illness unrelated to plaster treatment (n = 5). No patient discontinued because of inadequate analgesia or intolerable side effects. Reversible erythema occurred in two patients wearing the plaster for more than 16 h. There were no systemic side effects. The 5% lidocaine medicated plaster provides sustained pain relief over long-term treatment in patients with neuropathic pain of various causes and is well tolerated.

  8. Study and application of plasticity plaster-slurry for preventing coal spontaneous combustion

    Institute of Scientific and Technical Information of China (English)

    LIU Ai-hua(刘爱华); CAI Kang-xu(蔡康旭); GUO Da(郭达); ZHANG Fu-sheng(张复胜)

    2003-01-01

    Introduced the modulation scheme, function and mechanism of plasticity plaster-slurry preventing coal spontaneous combustion. The applications show that the plasticity plaster-slurry has good hygroscopicity and adsorptivity. To spray it on the coal wall of tunnel can shut off leakage wind fast and effectively. To press it into the coal body can absorb the heat and descend the temperature, surround the coal pieces, eliminate the possibility of the fiery district resuming combustion.

  9. The topical 5% lidocaine medicated plaster in localized neuropathic pain: a reappraisal of the clinical evidence

    Directory of Open Access Journals (Sweden)

    de León-Casasola OA

    2016-02-01

    Full Text Available Oscar A de León-Casasola,1,2 Victor Mayoral3 1Department of Anesthesiology, Division of Pain Medicine, Roswell Park Cancer Institute, 2University at Buffalo, School of Medicine and Biomedical Sciences. NY, USA; 3Anesthesiology Department, Pain Management Unit, University Hospital of Bellvitge, L'Hospitalet de Llobregat, Spain Abstract: Topical 5% lidocaine medicated plasters represent a well-established first-line option for the treatment of peripheral localized neuropathic pain (LNP. This review provides an updated overview of the clinical evidence (randomized, controlled, and open-label clinical studies, real-life daily clinical practice, and case series. The 5% lidocaine medicated plaster effectively provides pain relief in postherpetic neuralgia, and data from a large open-label controlled study indicate that the 5% lidocaine medicated plaster is as effective as systemic pregabalin in postherpetic neuralgia and painful diabetic polyneuropathy but with an improved tolerability profile. Additionally, improved analgesia and fewer side effects were experienced by patients treated synchronously with the 5% lidocaine medicated plaster, further demonstrating the value of multimodal analgesia in LNP. The 5% lidocaine medicated plaster provides continued benefit after long-term (≤7 years use and is also effective in various other LNP conditions. Minor application-site reactions are the most common adverse events associated with the 5% lidocaine medicated plaster; there is minimal risk of systemic adverse events and drug–drug interactions. Although further well-controlled studies are warranted, the 5% lidocaine medicated plaster is efficacious and safe in LNP and may have particular clinical benefit in elderly and/or medically compromised patients because of the low incidence of adverse events. Keywords: 5% lidocaine medicated plaster, clinical evidence, localized neuropathic pain, postherpetic neuralgia, review

  10. [Case-control study on close reduction and plaster slab fixation combined with plaster external traction for the treatment of pediatric Gartland type III supracondylar humerus fractures].

    Science.gov (United States)

    Kang, Yu-Xiang; Wei, Xiao-Chun; Li, Hai-Ming

    2014-07-01

    To compare the therapeutic effects between close reduction and plaster slab fixation combined with plaster external traction and operation for the treatment of pediatric closed Gartland type III supracondylar humerus fractures without neurovascular injury complications. From June 2009 to June 2012, 151 children with closed Gartland III supracondylar humerus fractures were retrospectively studied and divided into two groups, including 87 boys and 64 girls, ranging in age from 1 to 12 years old with an average of 5.3 years old. Among them, 76 children (conservative group) were treated with close reduction and plaster slab fixation combined with plaster external traction; 75 children (operation group) underwent surgical operation. The time of elbow joint function exercise, the healing time of fracture, the function recovery of elbow joint and carrying angle was recorded and analyzed. The therapeutic effects were evaluated by the Flynn criteria system. All patients were followed up from 6 to 36 months (18.3 months on average). The average time of fracture healing and elbow joint functional exercise of the conservative group was shorter than those of operation group (P 0.05). According to Flynn criteria system, in conservative group, the result was excellent in 31 cases, good in 35, fair in 7, and poor in 3; in operation group, 27 in excellent, 30 in good, 17 in fair and 1 in poor; there was no significant difference between two groups in therapeutic effects (P > 0.05). Close reduction and plaster slab fixation combined with plaster external traction in treatment of pediatric closed Gartland type III supracondylar humerus fractures without neurovascular injury complications,which has similar effect to surgical treatment, and the time of fracture healing and elbow joint function exercise are significantly shorter.

  11. Solder wetting behavior enhancement via laser-textured surface microcosmic topography

    Science.gov (United States)

    Chen, Haiyan; Peng, Jianke; Fu, Li; Wang, Xincheng; Xie, Yan

    2016-04-01

    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.

  12. Interaction Kinetics between Sn-Pb Solder Droplet and Au/Ni/Cu Pad

    Institute of Scientific and Technical Information of China (English)

    Fuquan LI; Chunqing WANG; Yanhong TIAN

    2006-01-01

    The interfacial phenomena of the Sn-Pb solder droplet on Au/Ni/Cu pad are investigated. A continuous AuSn2and needle-like AuSn4 are formed at the interface after the liquid state reaction (soldering). The interfacial reaction between the solder and Au layer continues during solid state aging with AuSn4 breaking off from the interface and felling into the solder. The kinetics of Au layer dissolution and diffusion into the solder during soldering and aging is analyzed to elucidate intermetallic formation mechanism at the solder/Au pad interface.The concentration of Au near the solder/pad interface is identified to increase and reach the solubility limit during the period of liquid state reaction. During solid state reaction, the thickening of Au-Sn compound is mainly controlled by element diffusion.

  13. Development of a new Pb-free solder: Sn-Ag-Cu

    Energy Technology Data Exchange (ETDEWEB)

    Miller, C.M.

    1995-02-10

    With the ever increasing awareness of the toxicity of Pb, significant pressure has been put on the electronics industry to get the Pb out of solder. This work pertains to the development and characterization of an alloy which is Pb-free, yet retains the proven positive qualities of current Sn-Pb solders while enhancing the shortcomings of Sn-Pb solder. The solder studied is the Sn-4.7Ag-1.7Cu wt% alloy. By utilizing a variety of experimental techniques the alloy was characterized. The alloy has a melting temperature of 217{degrees}C and exhibits eutectic melting behavior. The solder was examined by subjecting to different annealing schedules and examining the microstructural stability. The effect of cooling rate on the microstructure of the solder was also examined. Overall, this solder alloy shows great promise as a viable alternative to Pb-bearing solders and, as such, an application for a patent has been filed.

  14. A critical review of constitutive models for solders in electronic packaging

    National Research Council Canada - National Science Library

    Chen, Gang; Zhao, Xiaochen; Wu, Hao

    2017-01-01

    .... Because the failure of the whole electronic packaging is often induced by the failure of solders, modeling and simulation of solder joint performance are quite important in ensuring the quality...

  15. Microbial leaching of waste solder for recovery of metal.

    Science.gov (United States)

    Hocheng, H; Hong, T; Jadhav, U

    2014-05-01

    This study proposes an environment-friendly bioleaching process for recovery of metals from solders. Tin-copper (Sn-Cu), tin-copper-silver (Sn-Cu-Ag), and tin-lead (Sn-Pb) solders were used in the current study. The culture supernatant of Aspergillus niger removed metals faster than the culture supernatant of Acidithiobacillus ferrooxidans. Also, the metal removal by A. niger culture supernatant is faster for Sn-Cu-Ag solder as compared to other solder types. The effect of various process parameters such as shaking speed, temperature, volume of culture supernatant, and increased solder weight on bioleaching of metals was studied. About 99 (±1.75) % metal dissolution was achieved in 60 h, at 200-rpm shaking speed, 30 °C temperature, and by using 100-ml A. niger culture supernatant. An optimum solder weight for bioleaching was found to be 5 g/l. Addition of sodium hydroxide (NaOH) and sodium chloride (NaCl) in the bioleached solution from Sn-Cu-Ag precipitated tin (85 ± 0.35 %) and silver (80 ± 0.08 %), respectively. Passing of hydrogen sulfide (H2S) gas at pH 8.1 selectively precipitated lead (57.18 ± 0.13 %) from the Sn-Pb bioleached solution. The proposed innovative bioleaching process provides an alternative technology for recycling waste solders to conserve resources and protect environment.

  16. Antiemetic efficacy of capsicum plaster on acupuncture points in patients undergoing thyroid operation.

    Science.gov (United States)

    Koo, Min Seok; Kim, Kyo Sang; Lee, Hee-Jong; Jeong, Ji Seon; Lee, Jung-Won

    2013-12-01

    Postoperative nausea and vomiting (PONV) occurs in up to 63-84% of patients after thyroid surgery. This study aims to assess the effects of using a capsicum plaster to reduce PONV after thyroid surgery at either the Chinese acupuncture point (acupoint) Pericardium 6 (P6) or Korean hand acupuncture point K-D2. One-hundred eighty-four patients who underwent thyroid surgery were randomized in four groups (n = 46 each): control group = inactive tape at P6 acupoints and on both shoulders as a nonacupoint; P6 group = capsicum plaster at P6 points and inactive tape on both shoulders; K-D2 group = capsicum plaster at K-D2 acupoints and inactive tape on both shoulders; Sham group = capsicum plaster on both shoulders and inactive tape at P6 acupoints. The capsicum plaster was applied before the induction of anesthesia and removed at 8 hr after surgery. The incidence and severity of nausea and vomiting and the need for rescue antiemetics were decreased in the patients in the P6 and K-D2 groups compared to the patients in the control and sham groups (P plaster at the P6 and K-D2 acupoint was a promising antiemetic method for the patients undergoing thyroid surgery.

  17. Outcomes of pin and plaster versus locking plate in distal radius intraarticular fractures.

    Science.gov (United States)

    Bahari-Kashani, Mahmoud; Taraz-Jamshidy, Mohammad Hosein; Rahimi, Hassan; Ashraf, Hami; Mirkazemy, Masoud; Fatehi, Amirreza; Asadian, Mariam; Rezazade, Jafar

    2013-01-01

    Distal radius fractures are among the most prevalent fractures predictive of probable occurrence of other osteoporotic fractures. They are treated via a variety of methods, but the best treatment has not been defined yet. This study was performed to compare the results of open reduction and internal fixation with locking plates versus the pin and plaster method. In this prospective study, 114 patients aged 40 to 60 years with Fernandez type III fracture referring to Imam-Reza and Mehr hospitals of Mashhad from 2009 to 2011, were selected randomly; after obtaining informed consent, they were treated with pin and plaster fixation (n = 57) or internal fixation with the volar locking plate (n = 57). They were compared at the one year follow up. Demographic features and standard radiographic indices were recorded and MAYO, DASH and SF - 36 tests were performed. Data was analyzed by SPSS software version 13, with descriptive indices, Mann-Whitney and Chi-square tests. SF-36 test demonstrated a better general health (P plaster group. Also, in the LCP group mean MAYO score (P plaster group. Mean DASH score was not different between the groups (P = 0.218). The rate of acceptable results of radiographic indices (P plaster method. In treatment of intra-articular distal radius fractures in middle-aged patients internal fixation with locking plates may be prefered to pin and plaster as the treatment of choice.

  18. Digital versus plaster study models: how accurate and reproducible are they?

    Science.gov (United States)

    Abizadeh, Neilufar; Moles, David R; O'Neill, Julian; Noar, Joseph H

    2012-09-01

    To compare measurements of occlusal relationships and arch dimensions taken from digital study models with those taken from plaster models. Laboratory study The Orthodontic Department, Kettering General Hospital, Kettering, UK Methods and materials: One hundred and twelve sets of study models with a range of malocclusions and various degrees of crowding were selected. Occlusal features were measured manually with digital callipers on the plaster models. The same measurements were performed on digital images of the study models. Each method was carried out twice in order to check for intra-operator variability. The repeatability and reproducibility of the methods was assessed. Statistically significant differences between the two methods were found. In 8 of the 16 occlusal features measured, the plaster measurements were more repeatable. However, those differences were not of sufficient magnitude to have clinical relevance. In addition there were statistically significant systematic differences for 12 of the 16 occlusal features, with the plaster measurements being greater for 11 of these, indicating the digital model scans were not a true 11 representation of the plaster models. The repeatability of digital models compared with plaster models is satisfactory for clinical applications, although this study demonstrated some systematic differences. Digital study models can therefore be considered for use as an adjunct to clinical assessment of the occlusion, but as yet may not supersede current methods for scientific purposes.

  19. Analysis of solderability test methods: predicition model generation for through-hole components

    OpenAIRE

    Woods, Bobby

    2013-01-01

    peer-reviewed In order to achieve a reduction in solderability related defects on electronic components and Printed Circuit Board???s (PCB???s) in electronics manufacturing, preventive controls such as ???Dip & Look??? and ???Wetting Balance??? solderability testing need to be fully optimised to screen out all poor soldering components and PCB???s. Components and PCB???s that pass these tests should solder correctly in volume production. This thesis initially investigates the variations...

  20. Methylene blue solder re-absorption in microvascular anastomoses

    Science.gov (United States)

    Birch, Jeremy F.; Hepplewhite, J.; Frier, Malcolm; Bell, Peter R. F.

    2003-06-01

    Soldered vascular anastomoses have been reported using several chromophores but little is known of the optimal conditions for microvascular anastomosis. There are some indications of the optimal protein contents of a solder, and the effects of methylene blue on anastomotic strength. The effects of varying laser power density in vivo have also been described, showing a high rate of thrombosis with laser power over 22.9Wcm-2. However no evidence exists to describe how long the solder remains at the site of the anastomosis. Oz et al reported that the fibrin used in their study had been almost completely removed by 90 days but without objective evidence of solder removal. In order to address the issue of solder re-absorption from the site of an anastomosis we used radio-labelled albumin (I-125) incorporated into methylene blue based solder. This was investigated in both the situation of the patent and thrombosed anastomosis with anastomoses formed at high and low power. Iodine-125 (half life: 60.2 days) was covalently bonded to porcine albumin and mixed with the solder solution. Radio-iodine has been used over many years to determine protein turnover using either I-125 or I-131. Iodine-125 labelled human albumin is regularly used as a radiopharmaceutical tool for the determination of plasma volume. Radio-iodine has the advantages of not affecting protein metabolism and the label is rapidly excreted after metabolic breakdown. Labelling with chromium (Cr-51) causes protein denaturation and is lost from the protein with time. Labelled albumin has been reported in human studies over a 21-day period, with similar results reported by Matthews. Most significantly McFarlane reported a different rate of catabolism of I-131 and I-125 over a 22-day period. The conclusion from this is that the rate of iodine clearance is a good indicator of protein catabolism. In parallel with the surgery a series of blank standards were prepared with a known mass of solder to correct for isotope

  1. Reliability of lead-free solders in electronic packaging technology

    Science.gov (United States)

    Choi, Woojin

    The electromigration of flip chip solder bump (eutetic SnPb) has been studied at temperatures of 100, 125 and 150°C and current densities of 1.9 to 2.75 x 104 A/cm2. The under-bump-metallization on the chip side is thin film Al/Ni(V)/Cu and on the board side is thick Cu. By simulation, we found that current crowding occurs at the corner on the chip side where the electrons enter the solder ball. We are able to match this simulation to the real electromigration damage in the sample. The experimental result showed that voids initiated from the position of current crowding and propagated across the interface between UBM and the solder ball. The Cu-Sn intermetallic compounds formed during the reflow is known to adhere well to the thin film UBM, but they detached from the UBM after current stressing. Therefore, the UBM itself becomes part of the reliability problem of the flip chip solder joint under electromigration. Currently there is a renewed interest in Sn whisker growth owing to the introduction of Pb-free solder in electronic manufacturing. The leadframe is electroplated or finished with a layer of Pb-free solder. The solder is typically pure Sn or eutectic SnCu (0.7 atomic % Cu). It is a serious reliability concern in the use of the eutectic SnCu solder as leadframe surface finish due to the growth of long whiskers on it. The origin of the driving force of compressive stress can be mechanical, thermal, and chemical. Among them, the chemical force is the most important contribution to the whisker growth and its origin is due to the reaction between Sn and Cu to form intermetallic compound (IMC) at room temperature. For whisker or hillock growth, the surface cannot be free of oxide and it must be covered with oxide and the oxide must be a protective one so that it removes effectively all the vacancy sources and sinks on the surface. Hence, only those metals, which grow protective oxides such as Al and Sn, are known to have hillock growth or whisker growth. We

  2. 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, co...

  3. 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...

  4. 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...

  5. Photonic flash soldering of thin chips and SMD components on foils for flexible electronics

    NARCIS (Netherlands)

    Ende, D.A. van den; Hendriks, R.; Cauchois, R.; Kusters, R.H.L.; Cauwe, M.; Groen, W.A.; Brand, J. van den

    2014-01-01

    Ultrathin bare die chips and small-size surface mount device components were successfully soldered using a novel roll-to-roll compatible soldering technology. A high-power xenon light flash was used to successfully solder the components to copper tracks on polyimide (PI) and polyethylene terephthala

  6. Investigation Of Intermetallic Compounds In Sn-Cu-Ni Lead-Free Solders

    Directory of Open Access Journals (Sweden)

    Nagy E.

    2015-06-01

    Full Text Available Interfacial intermetallic compounds (IMC play an important role in Sn-Cu lead-free soldering. The size and morphology of the intermetallic compounds formed between the lead-free solder and the Cu substrate have a significant effect on the mechanical strength of the solder joint.

  7. Experimental Methods in Reduced-gravity Soldering Research

    Science.gov (United States)

    Pettegrew, Richard D.; Struk, Peter M.; Watson, John K.; Haylett, Daniel R.

    2002-01-01

    The National Center for Microgravity Research, NASA Glenn Research Center, and NASA Johnson Space Center are conducting an experimental program to explore the influence of reduced gravity environments on the soldering process. An improved understanding of the effects of the acceleration environment is important to application of soldering during current and future human space missions. Solder joint characteristics that are being considered include solder fillet geometry, porosity, and microstructural features. Both through-hole and surface mounted devices are being investigated. This paper focuses on the experimental methodology employed in this project and the results of macroscopic sample examination. The specific soldering process, sample configurations, materials, and equipment were selected to be consistent with those currently on-orbit. Other apparatus was incorporated to meet requirements imposed by operation onboard NASA's KC-135 research aircraft and instrumentation was provided to monitor both the atmospheric and acceleration environments. The contingent of test operators was selected to include both highly skilled technicians and less skilled individuals to provide a population cross-section that would be representative of the skill mix that might be encountered in space mission crews.

  8. Low-temperature solder for laser tissue welding

    Science.gov (United States)

    Lauto, Antonio; Stewart, Robert B.; Felsen, D.; Foster, John; Poole-Warren, Laura; Poppas, Dix P.

    2003-12-01

    In this study, a two layer (TL) solid solder was developed with a fixed thickness to minimize the difference in temperature across the solder (ΔT) and to weld at low temperature. Solder strips comprising two layers (65% albumin, 35% water) were welded onto rectangular sections of dog small intestine by a diode laser (λ = 808 nm). The laser delivered a power of 170 +/- 10 mW through an optical fiber (spot size approximately 1 mm) for 100 seconds. A solder layer incorporated also a dye (carbon black, 0.25%) to absorb the laser radiation. A thermocouple and an infrared thermometer system recorded the temperatures at the tissue interface and at the external solder surface, during welding. The repaired tissue was tested for tensile strength by a calibrated tensiometer. The TL strips were able to minimize ΔT (12 +/- 4°C) and control the temperature at tissue-interface. The strips fused on tissue at 55=70°C for tissue repair, which cause more irreversible thermal damage.

  9. [Treatment of ulcerative colitis with spleen and kidney yang deficiency by kuijiening plaster: a randomized controlled study].

    Science.gov (United States)

    Huang, Lei; Cai, Zhi; Zhu, Ying; Wan, Hu

    2013-07-01

    To explore the clinical efficacy of ulcerative colitis with spleen and kidney yang deficiency by kuijiening plaster and the impacts on IFN-gamma and IL-4 contents, as well as make the comparison with oral medication of sulfasalzine (SASP). Sixty patients of ulcerative colitis with spleen and kidney yang deficiency were randomized into a Kuijiening plaster group, a SASP group and a combined therapy group, 20 cases in each one. In the Kuijiening plaster group, Kuijiening plaster and oral administration of placebo SASP were applied. The plaster was used at Shangjuxu (ST 37), Tianshu (ST 25), Zusanli (ST 36), Mingmen (GV 4) and Guanyuan (CV 4). In the SASP group, was applied Kuijiening plaster placebo at the points and SASP oral administration was adopted. In the combined therapy group, Kuijiening plaster and SASP oral administration were given. The duration of treatment was 60 days. The follow-up visit was 2 months after treatment. The comprehensive efficacy, the efficacy on TCM syndrome and the changes in serum IFN-gamma and IL-4 before and after treatment were compared among the three groups. The efficacy on TCM syndrome in the Kuijiening plaster was similar to the SASP group [85.0% (17/20) vs 75.0% (15/20), P > 0.05]. The efficacy on TCM syndrome in the Kuijiening plaster group was superior to the western medicine group [80.0% (16/20) vs 60.0% (12/20), P plaster group were superior to the SASP group (P plaster is effective in the treatment of ulcerative colitis of spleen and kidney yang deficiency, which is not inferior to that of SASP. The efficacy of kuijiening plaster on relieving TCM syndrome and improving body immunity is much superior to SASP. The effect is much better with SASP combined in the treatment.

  10. Creep characterization of solder bumps using nanoindentation

    Science.gov (United States)

    Du, Yingjie; Liu, Xiao Hu; Fu, Boshen; Shaw, Thomas M.; Lu, Minhua; Wassick, Thomas A.; Bonilla, Griselda; Lu, Hongbing

    2017-08-01

    Current nanoindentation techniques for the measurement of creep properties are applicable to viscoplastic materials with negligible elastic deformations. A new technique for characterization of creep behavior is needed for situations where the elastic deformation plays a significant role. In this paper, the effect of elastic deformation on the determination of creep parameters using nanoindentation with a self-similar nanoindenter tip is evaluated using finite element analysis (FEA). It is found that the creep exponent measured from nanoindentation without taking into account of the contribution of elastic deformation tends to be higher than the actual value. An effective correction method is developed to consider the elastic deformation in the calculation of creep parameters. FEA shows that this method provides accurate creep exponent. The creep parameters, namely the creep exponent and activation energy, were measured for three types of reflowed solder bumps using the nanoindentation method. The measured parameters were verified using FEA. The results show that the new correction approach allows extraction of creep parameters with precision from nanoindentation data.

  11. Preparation of Plaster Moulage (Cast in Plastic Surgery patients

    Directory of Open Access Journals (Sweden)

    Rana R

    2003-01-01

    Full Text Available The purpose of this paper is to describe the technique of making casts using alginate compound for negative and dental stone plaster for positive impressions. With certain modifications a cast could be made of any part of the body and one can make a museum of interesting cases. Casts serve as useful teaching material especially in cleft lip and palate patients to study the effect of surgery on growth and development of the cleft lip-palate-nose complex in relation to the remaining face. It also helps in planning reconstruction in cases of facial defects, recording serial changes in multistage surgery, pre-operative and post-operative comparison as in rhinoplasty, ear reconstruction, hand etc; for comparing results before and after treatment in keloid and hypertrophic scars, fabrication of implants and preparation of prosthesis. In spite of newer modalities like 3-D imaging and stereolithography, the usefulness of this old technique in certain interesting cases can not be denied.

  12. Wet or dry bandages for plaster back-slabs?

    Science.gov (United States)

    Baliga, Santosh; Finlayson, D

    2012-12-01

    Cotton crêpe and stretch bandages are commonly used in back-slabs and casts in orthopaedic practice. In theory they allow swelling to occur after injury while splinting the fracture. The application of a wet bandage prevents the Plaster-of-Paris (POP) setting too rapidly, giving time to apply a mould or attain correct limb position. However, we hypothesised that a wet bandage contracts upon drying and may cause constriction of the splint. This study aimed at determining whether there was any significant change in length of commonly used bandages when wet as well as any further change when left to dry again. Two types of bandage were evaluated. 250 mm strips of bandage were dipped into water, gently squeezed and laid flat on a bench. The bandage was then immediately measured in length. The strips were then left to dry and re-measured. This experimental study shows that both cotton crepe and cling significantly shrink by around 7% when wet. This phenomenon has the potential to significantly increase the pressure exerted on the limb by a back-slab. We speculate that the application of wet bandages is why some back-slabs may need released. It is therefore recommended that bandages should be applied only in the dry form. Copyright © 2011 Royal College of Surgeons of Edinburgh (Scottish charity number SC005317) and Royal College of Surgeons in Ireland. Published by Elsevier Ltd. All rights reserved.

  13. 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.

  14. Effects of Solder Temperature on Pin Through-Hole during Wave Soldering: Thermal-Fluid Structure Interaction Analysis

    Science.gov (United States)

    Abdul Aziz, M. S.; Abdullah, M. Z.; Khor, C. Y.

    2014-01-01

    An efficient simulation technique was proposed to examine the thermal-fluid structure interaction in the effects of solder temperature on pin through-hole during wave soldering. This study investigated the capillary flow behavior as well as the displacement, temperature distribution, and von Mises stress of a pin passed through a solder material. A single pin through-hole connector mounted on a printed circuit board (PCB) was simulated using a 3D model solved by FLUENT. The ABAQUS solver was employed to analyze the pin structure at solder temperatures of 456.15 K (183°C) analysis. In addition, an experiment was conducted to measure the temperature difference (ΔT) between the top and the bottom of the pin. Analysis results showed that an increase in temperature increased the structural displacement and the von Mises stress. Filling time exhibited a quadratic relationship to the increment of temperature. The deformation of pin showed a linear correlation to the temperature. The ΔT obtained from the simulation and the experimental method were validated. This study elucidates and clearly illustrates wave soldering for engineers in the PCB assembly industry. PMID:25225638

  15. 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.

  16. Horizon Shells and BMS-like Soldering Transformations

    CERN Document Server

    Blau, Matthias

    2015-01-01

    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 ...

  17. Development of alternatives to lead-bearing solders

    Energy Technology Data Exchange (ETDEWEB)

    Vianco, P.T. [Sandia National Labs., Albuquerque, NM (United States)

    1993-07-01

    Soldering technology, using tin-lead alloys has had a significant role in the packaging of highly functional, low cost electronic devices. The elimination of lead from all manufactured products, whether through legislation or tax incentives, will impact the electronics community which uses lead-containing solders. In response to these proposed measures, the National Center for Manufacturing Sciences has established a multi-year program involving participants from industry, academia, and the national laboratories with the objective to identify potential replacements for lead-bearing solders. Selection of candidate alloys is based upon the analysis of materials properties, manufacturability, modeling codes for reliability prediction, as well as toxicological properties and resource availability, data developed in the program.

  18. Bosonisation and Duality Symmetry in the Soldering Formalism

    CERN Document Server

    Banerjee, R

    1998-01-01

    We develop a technique that solders the dual aspects of some symmetry. Using this technique it is possible to combine two theories with such symmetries to yield a new effective theory. Some applications in two and three dimensional bosonisation are discussed. In particular, it is shown that two apparently independent three dimensional massive Thirring models with same coupling but opposite mass signatures, in the long wavelegth limit, combine by the process of bosonisation and soldering to yield an effective massive Maxwell theory. Similar features also hold for quantum electrodynamics in three dimensions. We also provide a systematic derivation of duality symmetric actions and show that the soldering mechanism leads to a master action which is duality invariant under a bigger set of symmetries than is usually envisaged. The concept of duality swapping is introduced and its implications are analysed. The example of electromagnetic duality is discussed in details.

  19. Corrosion Issues in Solder Joint Design and Service

    Energy Technology Data Exchange (ETDEWEB)

    VIANCO,PAUL T.

    1999-11-24

    Corrosion is an important consideration in the design of a solder joint. It must be addressed with respect to the service environment or, as in the case of soldered conduit, as the nature of the medium being transported within piping or tubing. Galvanic-assisted corrosion is of particular concern, given the fact that solder joints are comprised of different metals or alloy compositions that are in contact with one-another. The (thermodynamic) potential for corrosion to take place in a particular environment requires the availability of the galvanic series for those conditions and which includes the metals or alloys in question. However, the corrosion kinetics, which actually determine the rate of material loss under the specified service conditions, are only available through laboratory evaluations or field data that are found in the existing literature or must be obtained by in-house testing.

  20. Materials chemistry. Composition-matched molecular "solders" for semiconductors.

    Science.gov (United States)

    Dolzhnikov, Dmitriy S; Zhang, Hao; Jang, Jaeyoung; Son, Jae Sung; Panthani, Matthew G; Shibata, Tomohiro; Chattopadhyay, Soma; Talapin, Dmitri V

    2015-01-23

    We propose a general strategy to synthesize largely unexplored soluble chalcogenidometallates of cadmium, lead, and bismuth. These compounds can be used as "solders" for semiconductors widely used in photovoltaics and thermoelectrics. The addition of solder helped to bond crystal surfaces and link nano- or mesoscale particles together. For example, CdSe nanocrystals with Na2Cd2Se3 solder was used as a soluble precursor for CdSe films with electron mobilities exceeding 300 square centimeters per volt-second. CdTe, PbTe, and Bi2Te3 powders were molded into various shapes in the presence of a small additive of composition-matched chalcogenidometallate or chalcogel, thus opening new design spaces for semiconductor technologies.

  1. Process characterization and control of hand-soldered printed wiring assemblies

    Energy Technology Data Exchange (ETDEWEB)

    Cheray, D.L.; Mandl, R.G.

    1993-09-01

    A designed experiment was conducted to characterize the hand soldering process parameters for manufacturing printed wiring assemblies (PWAs). Component tinning was identified as the most important parameter in hand soldering. After tinning, the soldering iron tip temperature of 700{degrees}F and the choice of operators influence solder joint quality more than any other parameters. Cleaning and flux/flux core have little impact on the quality of the solder joint. The need for component cleaning prior to assembly must be evaluated for each component.

  2. The impact of process parameters on gold elimination from soldered connector assemblies

    Energy Technology Data Exchange (ETDEWEB)

    VIANCO,PAUL T.; KILGO,ALICE C.

    2000-02-02

    Minimizing the likelihood of solder joint embrittlement in connectors is realized by reducing or eliminating retained Au plating and/or Au-Sn intermetallic compound formation from the assemblies. Gold removal is performed most effectively by using a double wicking process. When only a single wicking procedure can be used, a higher soldering temperature improves the process of Au removal from the connector surfaces and to a nominal extent, removal of Au-contaminated solder from the joint. A longer soldering time did not appear to offer any appreciable improvement toward removing the Au-contaminated solder from the joint. Because the wicking procedure was a manual process, it was operator dependent.

  3. A new active solder for joining electronic components

    Energy Technology Data Exchange (ETDEWEB)

    SMITH,RONALD W.; VIANCO,PAUL T.; HERNANDEZ,CYNTHIA L.; LUGSCHEIDER,E.; RASS,I.; HILLEN,F.

    2000-05-11

    Electronic components and micro-sensors utilize ceramic substrates, copper and aluminum interconnect and silicon. The joining of these combinations require pre-metallization such that solders with fluxes can wet such combinations of metals and ceramics. The paper will present a new solder alloy that can bond metals, ceramics and composites. The alloy directly wets and bonds in air without the use flux or premetallized layers. The paper will present typical processing steps and joint microstructures in copper, aluminum, aluminum oxide, aluminum nitride, and silicon joints.

  4. Lead Free Solder Joint Thermal Condition in Semiconductor Packaging

    Directory of Open Access Journals (Sweden)

    M. N. Harif

    2010-01-01

    Full Text Available Problem statement: Solder joints are responsible for both electrical and mechanical connections. Solder does not have adequate ductility to ensure the repeated relative displacements due to the mismatch between expansion coefficients of the chip carrier and the circuit board. Solder material plays a crucial role to provide the necessary electrical and mechanical interconnections in an electronic assembly. Finding a technique to increase the service life of future connections is not the total solution. A method must be developed for predicting the remaining service life of many joints already in use. Approach: The effect of High Temperature Storage (HTS on lead free solder joint material for ball grid array application using pull test method is studied in this study. Some statistical analysis base on the pull test data also discussed. Three samples of different lead free solder joint material were selected in this experiment namely Sn3.8Ag0.7Cu (SAC387, Sn2.3Ag0.08Ni0.01Co (SANC and Sn3.5Ag. After the thermal condition test, all the lead free solder joint material samples were tested using Dage 4000 pull test machine. Each pull test will be 5 units and each unit contains 8 balls. Results: The mean pull strength for high temperature storage is 2847.66, 2628.20 and 2613.79 g for Sn3.5Ag, SANC and SAC387, respectively. Thus, Sn3.5Ag shows a significantly better solder joint performance in terms of joint strength compare to SANC and SAC387. Hence, Intermetallic Compound (IMC thicknesses were measured after cross-sectioning. Sample size for cross-sectioning was 3 units per read point, 2 balls per unit and 3 maximum IMC peaks per ball and the measurement using high power scope of 100x and Image Analyzer software to measure the IMC thickness. For high temperature storage, result show that the mean IMC thicknesses for SAC387, SANC and Sn3.5Ag are 3.9139, 2.3111 and 2.3931 µm. Conclusion/Recommendations: It was found that IMC thickness for SANC and Sn3

  5. Comparison of space analysis performed on plaster vs. digital dental casts applying Tanaka and Johnston's equation.

    Science.gov (United States)

    Sanches, Júlia Olien; dos Santos-Pinto, Lourdes Aparecida Martins; dos Santos-Pinto, Ary; Grehs, Betina; Jeremias, Fabiano

    2013-01-01

    The purpose of this study was to compare dental size measurements, their reproducibility and the application of Tanaka and Johnston regression equation in predicting the size of canines and premolars on plaster and digital dental casts. Thirty plaster casts were scanned and digitized. Mesiodistal measurements of the teeth were then performed with a digital caliper on the plaster and digital casts using O3d software system (Widialabs©).The sum of the sizes of the lower incisors was used to obtain predictive values of the sizes of the premolars and canines using the regression equation, and these values were compared with the actual sizes of the teeth. The data were statistically analyzed by applying to the results Pearson's correlation test, Dahlberg's formula, paired t-test and analysis of variance (p plaster and digital casts. Despite an adequate reproducibility of the measurements performed on both casts, most measurements on the digital casts were higher than those on the plaster casts. The predicted space was overestimated in both models and significantly higher in the digital casts.

  6. The influence of composition of gypsum plaster on its technological properties

    Directory of Open Access Journals (Sweden)

    M. Pawlak

    2010-10-01

    Full Text Available Gypsum plasters used in art and precision foundry always are the composition of gypsum-silica-cristobalite. It is necessary considering the specifity of plaster during heating stage. Plaster undergoes then, structural transformations causing significant variations of its volume which are nonuniform and proceed with different intensity. The content of silica and cristobalite reduces dimensional variations of setted gypsum plaster what increases dimensional accuracy and significant stresses reduction limiting the possibility of mould cracks occurrence during heating.The influence of cristobalite and silica addition on basic gypsum plaster properties like setting time, dimensional changes after setting, bending strength and permeability in raw and heat treated state are presented in this paper. Experiments were done for mixes containing 30÷70% of the gypsum. It was proven that cristobalite has the biggest influence on the bounding time and expansion of the sandmix and the strength and permeability do not depend on the type of additions and only on theirs total amount in the composition.

  7. Application of Ceramic Powder as Supplementary Cementitious Material in Lime Plasters

    Directory of Open Access Journals (Sweden)

    Monika ČÁCHOVÁ

    2016-09-01

    Full Text Available In this paper, the properties of plasters based on lime – brick powder binder of varying composition (ceramics content from 0 to 80 % are studied. The plasters are prepared with a constant water amount. The pore size distribution is thus influenced in a positive way; the total porosity increases with the ceramics content but the volume of capillary pores is reduced. It results in lower water vapor diffusion resistance factor while the apparent moisture diffusivity coefficient increases just moderately. The influence of ceramic on strength of plasters is not found very important. The thermal conductivity of plasters containing ceramics is lower than those with the pure lime what is again in agreement with the pore size distribution. It can be concluded that fine brick powder can be used as pozzolanic admixture in lime based plasters with a positive influence on its functional parameters.DOI: http://dx.doi.org/10.5755/j01.ms.22.3.7433

  8. Antihyperalgesic efficacy of 5% lidocaine medicated plaster in capsaicin and sunburn pain models--two randomized, double-blinded, placebo-controlled crossover trials in healthy volunteers.

    Science.gov (United States)

    Gustorff, Burkhard; Hauer, David; Thaler, Johannes; Seis, Astrid; Draxler, Julia

    2011-12-01

    The aim of this research is to analyze analgesic efficacy of the 5% lidocaine medicated plaster in two randomized, double-blinded, placebo-controlled, crossover studies in 16 healthy volunteers using capsaicin and sunburn pain models. Lidocaine and placebo plasters were simultaneously applied to forearms and thighs at contralateral body sites for three alternating 12-h plaster-on/plaster-off periods. Between the second and third plaster-on period, 4.2-cm circular spots on both pretreated thighs were irradiated with three times the individual minimal erythema dose of UVB light. After the last plaster-on period, 20 μl of 0.1% capsaicin was injected intradermally into both forearms. The study was repeated using a single 12-h plaster application. The area of pinprick hyperalgesia was diminished by 53% (p plaster effectively treats mechanical hyperalgesia and cold pain.

  9. Studies on in situ particulate reinforced tin-silver composite solders relevant to thermomechanical fatigue issues

    Science.gov (United States)

    Choi, Sunglak

    2001-07-01

    Global pressure based on environmental and health concerns regarding the use of Pb-bearing solder has forced the electronics industry to develop Pb-free alternative solders. Eutectic Sn-Ag solder has received much attention as a potential Pb-free candidate to replace Sn-Pb solder. Since introduction of surface mount technology, packaging density increased and the electronic devices became smaller. As a result, solders in electronic modules are forced to function as a mechanical connection as well as electrical contact. Solders are also exposed to very harsh service conditions such as automotive under-the-hood and aerospace applications. Solder joints experience thermomechanical fatigue, i.e. interaction of fatigue and creep, during thermal cycling due to temperature fluctuation in service conditions. Microstructural study on thermomechanical fatigue of the actual eutectic Sn-Ag and Sn-4Ag-0.5Cu solder joints was performed to better understand deformation and damage accumulation occurring during service. Incorporation of reinforcements has been pursued to improve the mechanical and particularly thermomechanical behavior of solders, and their service temperature capability. In-situ Sn-Ag composite solders were developed by incorporating Cu 6Sn5, Ni3Sn4, and FeSn2 particulate reinforcements in the eutectic Sn-Ag solder in an effort to enhance thermomechanical fatigue resistance. In-situ composite solders were investigated on the growth of interfacial intermetallic layer between solder and Cu substrate growth and creep properties. Solder joints exhibited significant deformation and damage on free surface and interior regions during thermomechanical fatigue. Cracks initiated on the free surface of the solder joints and propagated toward interior regions near the substrate of the solder joint. Crack grew along Sn grain boundaries by grain boundary sliding. There was significant residual stress within the solder joint causing more damage. Presence of small amount of Cu

  10. Utilization of ground waste seashells in cement mortars for masonry and plastering.

    Science.gov (United States)

    Lertwattanaruk, Pusit; Makul, Natt; Siripattarapravat, Chalothorn

    2012-11-30

    In this research, four types of waste seashells, including short-necked clam, green mussel, oyster, and cockle, were investigated experimentally to develop a cement product for masonry and plastering. The parameters studied included water demand, setting time, compressive strength, drying shrinkage and thermal conductivity of the mortars. These properties were compared with those of a control mortar that was made of a conventional Portland cement. The main parameter of this study was the proportion of ground seashells used as cement replacement (5%, 10%, 15%, or 20% by weight). Incorporation of ground seashells resulted in reduced water demand and extended setting times of the mortars, which are advantages for rendering and plastering in hot climates. All mortars containing ground seashells yielded adequate strength, less shrinkage with drying and lower thermal conductivity compared to the conventional cement. The results indicate that ground seashells can be applied as a cement replacement in mortar mixes and may improve the workability of rendering and plastering mortar.

  11. Computational modeling of latent-heat-storage in PCM modified interior plaster

    Science.gov (United States)

    Fořt, Jan; Maděra, Jiří; Trník, Anton; Pavlíková, Milena; Pavlík, Zbyšek

    2016-06-01

    The latent heat storage systems represent a promising way for decrease of buildings energy consumption with respect to the sustainable development principles of building industry. The presented paper is focused on the evaluation of the effect of PCM incorporation on thermal performance of cement-lime plasters. For basic characterization of the developed materials, matrix density, bulk density, and total open porosity are measured. Thermal conductivity is accessed by transient impulse method. DSC analysis is used for the identification of phase change temperature during the heating and cooling process. Using DSC data, the temperature dependent specific heat capacity is calculated. On the basis of the experiments performed, the supposed improvement of the energy efficiency of characteristic building envelope system where the designed plasters are likely to be used is evaluated by a computational analysis. Obtained experimental and computational results show a potential of PCM modified plasters for improvement of thermal stability of buildings and moderation of interior climate.

  12. Effect of Tai Chi exercise in combination with auricular plaster on patients with lumbar muscle strain.

    Science.gov (United States)

    Lu, Tao; Song, Qing-Hua; Xu, Rong-Mei; Zhang, Li-Yan

    2015-01-01

    observe the effect of Tai Chi exercise on the patients with the chronic lumbar muscle strain under the intervention treatment of auricular plaster. 74 middle-aged and elderly patients, suffering from the chronic lumbar muscle strain, are randomly and equally divided into an observation group and a control group, with 37 patients in each group. The patients in the control group do Tai Chi exercise, while those in the observation group are treated by the auricular plaster therapy in addition to Tai Chi exercise. Evaluate and compare the disease conditions of the patients in the two groups before the treatment and after 12 weeks' treatment. after 12 weeks' treatment, the patients in the two groups have been improved differently in comparison with those before the treatment (P plaster therapy.

  13. Computational modeling of latent-heat-storage in PCM modified interior plaster

    Energy Technology Data Exchange (ETDEWEB)

    Fořt, Jan; Maděra, Jiří; Trník, Anton; Pavlíková, Milena; Pavlík, Zbyšek [Department of Materials Engineering and Chemistry, Faculty of Civil Engineering, Czech Technical University in Prague, Thákurova 7, 166 29 Prague (Czech Republic)

    2016-06-08

    The latent heat storage systems represent a promising way for decrease of buildings energy consumption with respect to the sustainable development principles of building industry. The presented paper is focused on the evaluation of the effect of PCM incorporation on thermal performance of cement-lime plasters. For basic characterization of the developed materials, matrix density, bulk density, and total open porosity are measured. Thermal conductivity is accessed by transient impulse method. DSC analysis is used for the identification of phase change temperature during the heating and cooling process. Using DSC data, the temperature dependent specific heat capacity is calculated. On the basis of the experiments performed, the supposed improvement of the energy efficiency of characteristic building envelope system where the designed plasters are likely to be used is evaluated by a computational analysis. Obtained experimental and computational results show a potential of PCM modified plasters for improvement of thermal stability of buildings and moderation of interior climate.

  14. The influence of inner hydrophobisation on water transport properties of modified lime plasters

    Science.gov (United States)

    Pavlíková, Milena; Pavlík, Zbyšek; Pernicová, Radka; Černý, Robert

    2016-06-01

    The effect of hydrophobic agent admixture on water vapour and liquid water transport properties of newly designed lime plasters is analysed in the paper. The major part of physico - chemical building deterioration is related to the penetration of moisture and soluble salts into the building structure. For that reason, the modified lime plasters were in the broad range of basic material properties tested. From the quantitative point of view, the measured results clearly demonstrate the big differences in the behaviour of studied materials depending on applied modifying admixtures. From the practical point of view, plaster made of lime hydrate, metakaolin, zinc stearate and air-entraining agent can be recommended for renovation purposes. The accessed material parameters will be used as input data for computational modelling of moisture transport in this type of porous building materials and will be stored in material database.

  15. [Ambulatory prevention of thrombosis with low molecular weight heparin in plaster immobilization of the lower extremity].

    Science.gov (United States)

    Kock, H J; Schmit-Neuerburg, K P; Hanke, J; Hakmann, A; Althoff, M; Rudofsky, G; Hirche, H

    1993-06-01

    Plaster cast immobilisation following trauma is a major risk factor for the development of deep vein thrombosis. In our controlled, randomized and prospective study on patients with minor injuries incidence of DVT in conservatively treated out-patients with plaster cast immobilisation of the leg was 3.9% in the control group (n = 126) without prophylaxis. By s.c. self-application of LMV heparin once daily the number of DVT in the prophylaxis group (n = 115) was reduced to 0. No severe side effects of NMH were observed. We conclude that thromboprophylaxis with LMW heparin once daily up to now conspiciously reduced the risk of DVT in outpatients with plaster cast immobilisation of the leg.

  16. CLINICAL OBSERVATION ON TREATMENT OF 61 CASES OF INSOMNIA WITH AURICULAR PLASTER THERAPY

    Institute of Scientific and Technical Information of China (English)

    张家彤; 王月

    2003-01-01

    Objective: To observe the therapeutic effect of auricular plaster (otopoint-pressure) therapy in thetreatment of insomnia. Methods: In this paper, 61 cases of insomnia patients including 16 males and 45 females weretreated with Ershenmen (MA-TF 1), Zhen (MA-AT), Yuanzhong (MA-AT), Nao Dian and E (MA-AT), combined withother otopoints according to symptoms. The otopoint was stuck with a piece of plaster adhered with vaccaria seeds andpressured by the patient him- or her-self. The treatment was given twice a week, with 7 times being a therapeuticcourse. Results: After 1 - 2 courses of treatment, 19 (31.15%) cases were cured, 34 (55.74 % ) had improvementand 8 (13.11%) had no changes, with the total effective rate being 86.9%. Conclusion: Auricular plaster therapyworks well in the treatment of insomnia patient.

  17. High-temperature lead-free solder alternatives

    DEFF Research Database (Denmark)

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

    2011-01-01

    For lead-free solders in the high-temperature regime, unfortunately, a limited number of alloying systems are available. These are Bi based alloys, gold involving alloys and Zn–Al based alloys. Based on these systems, possible candidate alloys were designed to have a melting range between 270°C a...

  18. Thermomechanical fatigue damage evolution in SAC solder joints

    NARCIS (Netherlands)

    Matin, M. A.; Vellinga, W. P.; D Geers, M. G.

    2007-01-01

    Thermornechanical fatigue in lab-type Sn-Ag-Cu solder interconnections between two copper plates has been investigated under cyclic thermal loading within a number of temperature ranges. Fatigue mechanisms have been studied using optical and scanning electron microscopy. Among the various fatigue me

  19. Porosity in collapsible Ball Grid Array solder joints

    Energy Technology Data Exchange (ETDEWEB)

    Gonzalez, C.A. [Univ. of California, Berkeley, CA (United States). Dept. of Materials Science and Mineral Engineering]|[Lawrence Berkeley National Lab., Berkeley, CA (United States). Materials Science Div.

    1998-05-01

    Ball Grid Array (BGA) technology has taken off in recent years due to the increased need for high interconnect density. Opposite to all the advantages BGA packages offer, porosity in collapsible BGA solder joints is often a major concern in the reliability of such packages. The effect of pores on the strength of collapsible BGA solder-joints was studied by manufacturing samples with different degrees of porosity and testing them under a shear load. It was found that the shear strength of the solder joints decreased in a linear fashion with increasing porosity. Failure occurred by internal necking of the interpore matrix. It was confirmed that entrapment of flux residues leads to porosity by manufacturing fluxless samples in a specially made furnace, and comparing them with samples assembled using flux. Also, contamination of Au electrodeposits (in substrate metallization) was determined to cause significant porosity. It was found that hard-Au (Co hardened Au) electrodeposits produce high degrees of porosity even in the absence of flux. Finally, increasing the time the solder spends in the molten state was proven to successfully decrease porosity.

  20. Fundamentals of wetting and spreading with emphasis on soldering

    Energy Technology Data Exchange (ETDEWEB)

    Yost, F.G.

    1991-01-01

    Soldering is often referred to as a mature technology whose fundamentals were established long ago. Yet a multitude of soldering problems persist, not the least of which are related to the wetting and spreading of solder. The Buff-Goodrich approach to thermodynamics of capillarity is utilized in a review of basic wetting principles. These thermodynamics allow a very compact formulation of capillary phenomena which is used to calculate various meniscus shapes and wetting forces. These shapes and forces lend themselves to experimental techniques, such as the sessile drop and the Wilhelmy plate, for measuring useful surface and interfacial energies. The familiar equations of Young, Wilhelmy, and Neumann are all derived with this approach. The force-energy duality of surface energy is discussed and the force method is developed and used to derive the Herring relations for anisotropic surfaces. The importance of contact angle hysteresis which results from surface roughness and chemical inhomogeneity is presented and Young's equation is modified to reflect these ever present effects. Finally, an analysis of wetting with simultaneous metallurigical reaction is given and used to discuss solder wetting phenomena. 60 refs., 13 figs.

  1. Horizon shells and BMS-like soldering transformations

    Science.gov (United States)

    Blau, Matthias; O'Loughlin, Martin

    2016-03-01

    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.

  2. Thermomechanical fatigue damage evolution in SAC solder joints

    NARCIS (Netherlands)

    Matin, M. A.; Vellinga, W. P.; D Geers, M. G.

    2007-01-01

    Thermornechanical fatigue in lab-type Sn-Ag-Cu solder interconnections between two copper plates has been investigated under cyclic thermal loading within a number of temperature ranges. Fatigue mechanisms have been studied using optical and scanning electron microscopy. Among the various fatigue me

  3. Printed-Circuit-Board Soldering Training for Group IV Personnel.

    Science.gov (United States)

    Hooprich, E. A.; Matlock, E. W.

    As part of a larger program to determine which Navy skills can be learned by lower aptitude personnel, and which methods and techniques would be most effective, an experimental course in printed circuit board soldering was given to 186 Group IV students in 13 classes. Two different training approaches--one stressing instructor guidance and the…

  4. 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.

  5. Recycling of lead solder dross, Generated from PCB manufacturing

    Science.gov (United States)

    Lucheva, Biserka; Tsonev, Tsonio; Iliev, Peter

    2011-08-01

    The main purpose of this work is to analyze lead solder dross, a waste product from manufacturing of printed circuit boards by wave soldering, and to develop an effective and environmentally sound technology for its recycling. A methodology for determination of the content and chemical composition of the metal and oxide phases of the dross is developed. Two methods for recycling of lead solder dross were examined—carbothermal reduction and recycling using boron-containing substances. The influence of various factors on the metal yield was studied and the optimal parameters of the recycling process are defined. The comparison between them under the same parameters-temperature and retention time, showed that recycling of dross with a mixture of borax and boric acid in a 1:2 ratio provides higher metal yield (93%). The recycling of this hazardous waste under developed technology gets glassy slag and solder, which after correction of the chemical composition can be used again for production of PCB.

  6. Monitoring of the moisture and salt load in restoration plasters in St.-Barbara' s church in Culemborg

    NARCIS (Netherlands)

    Hees, R.P.J. van; Sanders, M.M.

    2005-01-01

    St. Barbara's Church in Culemborg in the Netherlands has a history of moisture and salt damage to the plaster. In the past several restorations were performed, without a durable results. Finally, in 1997 test panels were applied in oreder to bas the choice for new plastering on in practice proved

  7. Evaluation of physical-mechanical properties of 3 brands of plaster of Paris in the Kenyan market.

    Science.gov (United States)

    Mwaniki, D L

    1990-05-01

    In this study, 3 brands of plaster of Paris that are available in the Kenyan Market for prosthetics and dental rehabilitation uses were subjected to physical-mechanical tests. The particles in two of the brands that had been imported were finer than a locally made plaster since less than 1.41% of their particles were larger than 150 microns compared to 15.2% in the local plaster. The range of their setting times was between 7.5 and 27.5 min. and was within the International Standards Organisation (ISO) recommendation. The water:power ratios required to produce plaster mixes of standard consistency for the locally made plaster was about 1.5 times of other brands. In compression, the mean 1-hour strength of local plaster was 2.5 MN/m2 (Mega Newtons per square metre) compared to 6.81 MN/m2 and 8.95 MN/m2 for the other brands. The differences between these strength values were highly significant (p less than 0.01). There were no significant differences in deformation of fracture for the 3 brands whose range was 1.32% to 1.71%. In order to obviate the need to import plaster, strict manufacturing techniques of locally made plaster are recommended.

  8. Roles of interfacial reaction on mechanical properties of solder interfaces

    Science.gov (United States)

    Liu, Pilin

    This study investigated roles of interfacial reaction in fracture and fatigue of solder interconnects. The interfacial reaction phases in the as-reflowed and after aging were examined by cross-sectional transmission electron microscopy (TEM) while interfacial mechanical properties were determined from a flexural peel fracture mechanics technique. Because of their widespread uses in microelectronic packaging, SnPb solder interfaces, and Bi-containing Pb-free solder interfaces were chosen as the subjects of this study. In the interfacial reaction study, we observed a complicated micro structural evolution during solid-state aging of electroless-Ni(P)/SnPb solder interconnects. In as-reflowed condition, the interfacial reaction produced Ni3Sn 4 and P-rich layers. Following overaging, the interfacial microstructure degenerated into a complex multilayer structure consisting of multiple layers of Ni-Sn compounds and transformed Ni-P phases. In SnPb solder interfacial system, fatigue study showed that the overaging of the high P electroless Ni-P/SnPb interconnects resulted in a sharp reduction in the fatigue resistance of the interface in the high crack growth rate regime. Fracture mechanism analysis indicated that the sharp drop in fatigue resistance was triggered by the brittle fracture of the Ni3Sn2 intermetallic phase developed at the overaged interface. The fatigue behavior was strongly dependent on P concentration in electroless Ni. Kirkendall voids were found in the interfacial region after aging, but they did not cause premature fracture of the solder interfaces. In Bi-containing solder interfacial system, we found that Bi segregated to the Cu-intermetallic interface during aging in SnBi/Cu interconnect. This caused serious embrittlement of Sn-Bi/Cu interface. Further aging induced numerous voids along the Cu3Sn/Cu interface. These interfacial voids were different from Kirkendall voids. Their formation was explained on basis of vacancy condensation at the

  9. Accuracy and reproducibility of measurements on plaster models and digital models created using an intraoral scanner.

    Science.gov (United States)

    Camardella, Leonardo Tavares; Breuning, Hero; de Vasconcellos Vilella, Oswaldo

    2017-05-01

    The purpose of the present study was to evaluate the accuracy and reproducibility of measurements made on digital models created using an intraoral color scanner compared to measurements on dental plaster models. This study included impressions of 28 volunteers. Alginate impressions were used to make plaster models, and each volunteers' dentition was scanned with a TRIOS Color intraoral scanner. Two examiners performed measurements on the plaster models using a digital caliper and measured the digital models using Ortho Analyzer software. The examiners measured 52 distances, including tooth diameter and height, overjet, overbite, intercanine and intermolar distances, and the sagittal relationship. The paired t test was used to assess intra-examiner performance and measurement accuracy of the two examiners for both plaster and digital models. The level of clinically relevant differences between the measurements according to the threshold used was evaluated and a formula was applied to calculate the chance of finding clinically relevant errors on measurements on plaster and digital models. For several parameters, statistically significant differences were found between the measurements on the two different models. However, most of these discrepancies were not considered clinically significant. The measurement of the crown height of upper central incisors had the highest measurement error for both examiners. Based on the interexaminer performance, reproducibility of the measurements was poor for some of the parameters. Overall, our findings showed that most of the measurements on digital models created using the TRIOS Color scanner and measured with Ortho Analyzer software had a clinically acceptable accuracy compared to the same measurements made with a caliper on plaster models, but the measuring method can affect the reproducibility of the measurements.

  10. Effect of cotton padding on the setting properties of plaster slabs.

    Science.gov (United States)

    Barlow, D; Bansal, R; Barlow, T; Rhee, S J; Kuiper, J H; Makwana, N K

    2013-03-01

    Plaster of Paris (PoP) impregnated bandages have been used to maintain the position of bones and joints for over a century. Classically, wool dressing is applied to the limb before the PoP, which can then be moulded to the desired shape. A modification of this practice is to wrap the PoP bandages circumferentially in cotton before wetting and applying to the patient in an attempt to reduce inhalation of plaster dust and reduce mess. However, this may affect the water content of the cast and therefore also its setting properties and strength. This study compared the setting properties of PoP casts when used with and without cotton wrapping. Sixty specimens, compliant with the American Society for Testing and Materials standards for three-point bending tests, were prepared, with thirty wrapped in cotton. All were weighed before and after water immersion, and wrapped around a plastic cylinder to mimic limb application. Bending stiffness and yield strength was measured on a servohydraulic materials testing machine at 2, 6, 12, 24, 48 and 72 hours. The water content of cotton-wrapped plaster was significantly higher (50%) than that of standard plaster. It had significantly lower strength up to 24 hours and significantly lower stiffness up to 72 hours. The initial decrease in strength and stiffness of the cast wrapped in cotton may comprise the ability of the backslab to hold the joint or bone in an optimal position. Any modification of the standard plaster slab application technique should allow for the potential adverse effects on the plaster setting properties.

  11. FORMATION AND CHANGE OF AuSn4 COMPOUNDS AT INTERFACE BETWEEN PBGA SOLDER BALL AND Au/Ni/Cu METALLIZATION DURING LASER AND INFRA-RED REFLOW SOLDERING

    Institute of Scientific and Technical Information of China (English)

    Y.H.Tian; C.Q.Wang

    2004-01-01

    Interactions between 63Sn37Pb solder and PBGA metallization(Au/Ni/Cu)during laser and infrared reflow soldering were studied.During laser refow soldering process,a thin layer of AuSn4 was observed at the interface of the solder bumps,its morphology was strongly dependent on the laser reflow power and heating time.The solder bumps formed by the first laser reflow was refowed again to form the solder joints.The AuSn4 compounds formed in the first laser reflow process dissolved into the bulk solder after the secondary infrared reflow process.The needle-like AuSn4 changed into rodlike,and distributed inside the solder near the solder/pad interface.

  12. A Comparative Evaluation of Mixed Dentition Analysis on Reliability of Cone Beam Computed Tomography Image Compared to Plaster Model.

    Science.gov (United States)

    Gowd, Snigdha; Shankar, T; Dash, Samarendra; Sahoo, Nivedita; Chatterjee, Suravi; Mohanty, Pritam

    2017-01-01

    The aim of the study was to evaluate the reliability of cone beam computed tomography (CBCT) obtained image over plaster model for the assessment of mixed dentition analysis. Thirty CBCT-derived images and thirty plaster models were derived from the dental archives, and Moyer's and Tanaka-Johnston analyses were performed. The data obtained were interpreted and analyzed statistically using SPSS 10.0/PC (SPSS Inc., Chicago, IL, USA). Descriptive and analytical analysis along with Student's t-test was performed to qualitatively evaluate the data and P plaster model; the mean for Moyer's analysis in the left and right lower arch for CBCT and plaster model was 21.2 mm, 21.1 mm and 22.5 mm, 22.5 mm, respectively. CBCT-derived images were less reliable as compared to data obtained directly from plaster model for mixed dentition analysis.

  13. Efficacy of the topical 5% lidocaine medicated plaster in the treatment of chronic post-thoracotomy neuropathic pain.

    Science.gov (United States)

    Sansone, Pasquale; Passavanti, Maria Beatrice; Fiorelli, Alfonso; Aurilio, Caterina; Colella, Umberto; De Nardis, Lorenzo; Donatiello, Valerio; Pota, Vincenzo; Pace, Maria Caterina

    2017-05-01

    To assess the efficacy of the topical 5% lidocaine medicated plaster (Versatis(®), Grünenthal GmbH, Aachen, Germany) in patients with post-thoracotomy neuropathic pain. Patients were randomized to receive the topical 5% lidocaine medicated plaster (n = 33) or non-medicated placebo plasters (n = 30) for 12 h every day for 8 weeks. Laser-evoked potentials (LEPs) were measured, and various questionnaires/scales completed. Numeric Rating Scale pain scores improved significantly (p plaster than in placebo recipients. The same was true for N2 and P2 LEP latency and amplitude, and other parameters. The study included neurophysiological findings and confirmed the efficacy of the topical 5% lidocaine medicated plaster in patients with chronic post-thoracotomy neuropathic pain.

  14. 5% Lidocaine-medicated plaster for the treatment of chronic peripheral neuropathic pain: complex regional pain syndrome and other neuropathic conditions.

    Science.gov (United States)

    Calderón, Enrique; Calderón-Seoane, María Eloísa; García-Hernández, Rafael; Torres, Luis Miguel

    2016-01-01

    Chronic neuropathic pain and chronic complex regional pain syndrome (CRPS), in particular, are debilitating and difficult-to-treat conditions that have a strong impact on patient's quality of life. The aim of this study was to evaluate the effectiveness of 5% lidocaine-medicated plaster as add-on therapy in patients with chronic peripheral neuropathic pain conditions, including CRPS. This was a single-center, prospective, observational study set in a specialized pain unit of a tertiary hospital in Spain. A total of 56 patients with long-standing peripheral neuropathic pain, ten of them with CRPS, received 5% lidocaine-medicated plaster as add-on analgesic therapy for 6 months. After 6 months of treatment, a ≥50% reduction in pain intensity was attained by 75% of patients, as measured by numeric rating scale (NRS) for pain. The average NRS score was reduced by 61% (4.7 points), from a baseline mean score of 7.8 to an end point mean score of 3.1. Marked improvements were also observed in the CRPS group: six out of ten patients achieved a ≥50% reduction in NRS score, and the average NRS score for patients with CRPS was reduced by 51% (4.0 points), from a baseline mean score of 7.9 to an end point mean score of 3.9. The improvements in pain intensity were partially translated into a decrease in disability index and in anxiety levels. 5% Lidocaine-medicated plaster may be useful as add-on therapy for a number of peripheral neuropathic pain conditions, including CRPS.

  15. 针刺结合耳穴治疗失眠临床观察%A Randomized Control Study of Acupuncture Plus Auricular-plaster Therapy for Insomnia

    Institute of Scientific and Technical Information of China (English)

    赖旖; 罗敏; 邱剑锋

    2011-01-01

    Objective : To investigate the efficacy of acupuncture plus auricular-plaster therapy in treating insomnia. Methods: Twenty patients with insomnia were randomly allocated to two groups, acupuncture plus auricular-plaster ( study group )and simple medication with diazepam ( control group ). One course of treatment consisted of four weeks. The Pittsburgh Sleep Quality Index ( PSQI ) was used to assess sleep quality in both groups before and after treatment. A difference of PSQI score between pretreatment and posttreatment was compared between the groups. Results: After treatment there was a significant difference in clinical therapeutic effect between the study and control groups ( P<0.05 ) . Conclusion ; Acupuncture plus auricular-plaster therapy has a marked therapeutic effect on insomnia and is an effective therapy for treating insomnia.%目的:观察针刺结合耳穴贴压治疗失眠的临床疗效.方法:将40例失眠患者随即分为两组,针刺结合耳穴组(观察组)和单纯药物组(对照组),4周为1疗程.两组在治疗前后分别进行匹兹堡睡眠质量指数测验( PSQI),观察指数前后差值作组间比较.结果:经过治疗后,两组疗效比较,差异有统计学意义(P<0.05).结论:针刺结合耳穴治疗失眠疗效显著.

  16. Electromigration Behaviors of Cu Reinforced Sn-3.5Ag Composite Solder Joints

    Science.gov (United States)

    Wang, Yan; Han, Jing; Ma, Limin; Zuo, Yong; Guo, Fu

    2016-09-01

    The composite approach, by incorporating small amounts of reinforcement particles in the solder matrix, has proven to be one of the effective ways to improve the reliability of solder joints. The effects of Cu addition on electromigration were investigated in this study by incorporating 2% volume fraction Cu particles into Sn-3.5Ag eutectic solder paste by the in situ process. The one-dimensional solder joints, designed to prevent the current crowding effect, were stressed under a constant current density of 104 A/cm2 at room temperature, and the temperature of the sample could reach 105 ± 5°C due to the Joule heating effect. Doping 2 vol.% Cu was found to retard the electromigration phenomenon effectively. After electric current stressing for 528 h, the growth rate of an interfacial intermetallic compound (IMC) layer at the anode decreased 73% in contrast to that of Sn-3.5Ag solder joints, and the IMC layer at the cathode was almost unchanged. The polarization effect of Cu reinforced composite solder joints was also apparently mitigated. In addition, the surface damage of the composite solder joints was relieved by incorporating 2 vol.% Cu particles. Compared to Sn-3.5Ag solder joints, which had protruded Cu6Sn5 and wrinkles of Sn-solder matrix on the surface, the solder joints with Cu addition had a more even surface.

  17. Electromigration Behaviors of Cu Reinforced Sn-3.5Ag Composite Solder Joints

    Science.gov (United States)

    Wang, Yan; Han, Jing; Ma, Limin; Zuo, Yong; Guo, Fu

    2016-12-01

    The composite approach, by incorporating small amounts of reinforcement particles in the solder matrix, has proven to be one of the effective ways to improve the reliability of solder joints. The effects of Cu addition on electromigration were investigated in this study by incorporating 2% volume fraction Cu particles into Sn-3.5Ag eutectic solder paste by the in situ process. The one-dimensional solder joints, designed to prevent the current crowding effect, were stressed under a constant current density of 104 A/cm2 at room temperature, and the temperature of the sample could reach 105 ± 5°C due to the Joule heating effect. Doping 2 vol.% Cu was found to retard the electromigration phenomenon effectively. After electric current stressing for 528 h, the growth rate of an interfacial intermetallic compound (IMC) layer at the anode decreased 73% in contrast to that of Sn-3.5Ag solder joints, and the IMC layer at the cathode was almost unchanged. The polarization effect of Cu reinforced composite solder joints was also apparently mitigated. In addition, the surface damage of the composite solder joints was relieved by incorporating 2 vol.% Cu particles. Compared to Sn-3.5Ag solder joints, which had protruded Cu6Sn5 and wrinkles of Sn-solder matrix on the surface, the solder joints with Cu addition had a more even surface.

  18. Environmentally friendly solders 3-4 beyond Pb-based systems

    Institute of Scientific and Technical Information of China (English)

    GAO Yuan; LIU Peng; GUO Fu; XIA Zhidong; LEI Yongping; SHI Yaowu

    2006-01-01

    Based on environmental considerations, global economic pressures, enacted by legislations in several countries, have warranted the elimination of lead from solders used in electronic applications.Sn3.5Ag, SnAgCu, and Sn0.7Cu have emerged among various lead-free candidates as the most promising solder alloys to be utilized in microelectronic industries.However, with the vast development and miniaturization of modern electronic packaging, new requirements such as superior service capabilities have been posed on lead-free solders.In order to improve the comprehensive property of the solder alloys, two possible approaches were adopted in the current research and new materials developed were patented.One approach was involved with the addition of alloying elements to make new ternary or quaternary solder alloys.Proper addition of rare earth element such as La and Ce have rendered solder alloys with improved mechanical properties, especially creep rupture lives of their joints.Another approach, the composite approach, was developed mainly to improve the service temperature capability of the solder alloys.Composite solders fabricated by mechanically incorporating various reinforcement particles to the solder paste have again exhibited enhanced properties without altering the existing processing characteristics.The recent progress and research efforts carried out on lead-free solder materials in Beijing University of Technology were reported.The effects of rare earth addition on the microstructure, processing properties, and mechanical properties were presented.The behaviors of various Sn-3.5Ag based composite solders were also explicated in terms of the roles of reinforcement particles on intermetallic growth, steady-state creep rate, the onset of tertiary creep, as well as the overall creep deformation in the solder joints.Thermomechanical fatigue (TMF) behavior of the solder alloys and composite solders were investigated with different parameters such as ramp rate

  19. 小青龙贴中挥发油的提取工艺研究%Study on the Extraction Process of Volatile Oil in Xiaoqinglong Plaster

    Institute of Scientific and Technical Information of China (English)

    徐志红; 陈磊垚; 刘欣怡

    2013-01-01

    Objective To optimize the best conditions of the extraction process of volatile oil in xi-aoqinglong plaster. Methods L9( 34 ) orthogonal test was adopted. The extraction rate of volatile oil was taken as the observation index. It was to observe the impacts of water amount, soak time and extraction time on the extraction rate of volatile ole in xiaoqinglong plaster. Results The extraction and soak time brought the best impact on the extraction of volatile oil, presenting the best significance. The water volume impacted less on the results. In consideration with the actual production, the final decision of the extraction process of volatile oil in xiaoqinglong plaster was: adding water 8 times as the weight of herbal materials, soaking for 1 h, steam distillation for 6 h. Conclusion In the verification test, the extraction rate of xiaoqinglong plaster of 3 batches is stable; the optimized extraction process of volatile oil is simple,stable and feasible. This process is suitable to be applied in the industrialized production.%目的 优选小青龙贴中挥发油的最佳提取工艺条件.方法 采用L9(34)正交试验方法,以得油率为考察指标,考察加水量、浸泡时间和提取时间三个因素对小青龙贴中得油率的影响.结果 提取时间和浸泡时间对提取挥发油的影响最大,最有显著性意义,加水量对结果的影响较小.结合实际生产,最终确定小青龙贴中挥发油的提取工艺为:药材加8倍量水,浸泡1 h,水蒸气蒸馏6 h.结论 验证试验中三批小青龙贴得油率稳定,所优选的挥发油提取工艺简单、稳定、可行,适用于工业化大生产.

  20. Effects of particle size on the mechanical properties of particle-reinforced Sn-Ag composite solder joint

    Institute of Scientific and Technical Information of China (English)

    2009-01-01

    Particulate size has significant influenced on the mechanical properties of particle-reinforced composite solder joints. In this current research, Cu or Ni reinforcement particles were mechanically added to the Sn-3.5Ag eutectic solder, and the effects of the particle size on the mechanical properties of particle-reinforced composite solder joint were systematically studied. This investigation touched on how mechanical properties of the solder joints are affected by particles size. A quantitative formula was set up to correlate the mechanical property of the solder joint with particle size in different processing conditions. Besides, the fracture mechanism of the composite solder joint was analyzed.

  1. Root Cause Investigation of Lead-Free Solder Joint Interfacial Failures After Multiple Reflows

    Science.gov (United States)

    Li, Yan; Hatch, Olen; Liu, Pilin; Goyal, Deepak

    2017-03-01

    Solder joint interconnects in three-dimensional (3D) packages with package stacking configurations typically must undergo multiple reflow cycles during the assembly process. In this work, interfacial open joint failures between the bulk solder and the intermetallic compound (IMC) layer were found in Sn-Ag-Cu (SAC) solder joints connecting a small package to a large package after multiple reflow reliability tests. Systematic progressive 3D x-ray computed tomography experiments were performed on both incoming and assembled parts to reveal the initiation and evolution of the open failures in the same solder joints before and after the reliability tests. Characterization studies, including focused ion beam cross-sections, scanning electron microscopy, and energy-dispersive x-ray spectroscopy, were conducted to determine the correlation between IMC phase transformation and failure initiation in the solder joints. A comprehensive failure mechanism, along with solution paths for the solder joint interfacial failures after multiple reflow cycles, is discussed in detail.

  2. 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 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.

  3. Far infrared emitting plaster in knee osteoarthritis: a single blinded, randomised clinical trial

    Directory of Open Access Journals (Sweden)

    N. Marino

    2012-12-01

    Full Text Available Objective. Therapeutic approach of osteoarthritis (OA still represents a challenge in clinical practice. The aim of the study is to assess the efficacy of far infrared (FIR emitting plaster in the treatment of knee OA. Design. This is a randomized, single-blind, placebo-controlled, parallel group with equal randomization (1:1, clinical trial. Patients affected by knee OA were randomly allocated to 1 of 2 treatment groups, either placebo plaster or far infrared emitting plaster. Primary endpoint was to assess pain improvement from baseline to 1 months posttreatment in the visual analogue score (VAS. Secondary end point was to evaluate pain score after 1 week of treatment and to compare ultrasonographic findings after 1 month of treatment. Results. Each group comprised 30 (in the FIR group and 30 (in the placebo group completers. VAS scores of the placebo and the FIR group were significantly lower at 1 week post-treatment (95% confidence interval CI = -1.14 to 0.31; PConclusions. Far infrared emitting plaster could be considered an effective non-pharmacological choice for the therapeutic management of knee OA.

  4. Health economic evidence of 5% lidocaine medicated plaster in post-herpetic neuralgia.

    Science.gov (United States)

    Liedgens, Hiltrud; Obradovic, Marko; Nuijten, Mark

    2013-11-25

    Post-herpetic neuralgia (PHN) is the most common and most debilitating complication of herpes zoster, and involves considerable associated costs. This paper presents results from nine health economic studies undertaken in eight European countries that compared lidocaine medicated plaster with gabapentin and/or pregabalin in PHN. It aims to support the increasing need for published cost-effectiveness data for health care decision-making processes in Europe. All studies were based on a similar core Markov model with data derived from clinical trials, local Delphi panels, and official national price and tariff lists. The main outcome measure was cost per quality-adjusted life year gained; time without pain or intolerable adverse events was also included as a secondary outcome measure. All studies focused on an elderly population of patients with PHN who had insufficient pain relief with standard analgesics and could not tolerate or had contraindications to tricyclic antidepressants. Despite considerable differences in many of the variables used, the results showed remarkable similarity and suggested that use of lidocaine medicated plaster offered cost-savings in many of the countries studied, where it proved a highly cost-effective alternative to both gabapentin and pregabalin. Lidocaine medicated plaster is a cost-effective alternative to gabapentin and pregabalin in the treatment of PHN. These savings are largely the result of the superior safety profile of the lidocaine medicated plaster.

  5. Fragmentation, Cost and Environmental Effects of Plaster Stemming Method for Blasting at A Basalt Quarry

    Science.gov (United States)

    Cevizci, Halim

    2014-10-01

    In this study, the plaster stemming application for blasting at a basalt quarry is studied. Drill cuttings are generally used in open pits and quarries as the most common stemming material since these are most readily available at blast sites. However, dry drill cuttings eject very easily from blastholes without offering much resistance to blast energy. The plaster stemming method has been found to be better than the drill cuttings stemming method due to increased confinement inside the hole and better utilization of blast explosive energy in the rock. The main advantage of the new stemming method is the reduction in the cost of blasting. At a basalt quarry, blasting costs per unit volume of rock were reduced to 15% by increasing burden and spacing distances. In addition, better fragmentation was obtained by using the plaster stemming method. Blast trials showed that plaster stemming produced finer material. In the same blast tests, +30 cm size fragments were reduced to 47.3% of the total, compared to 32.6% in the conventional method of drill cuttings stemming. With this method of stemming, vibration and air shock values increased slightly due to more blast energy being available for rock breakage but generally these increased values were small and stayed under the permitted limit for blast damage criteria unless measuring distance is too close.

  6. Digital model as an alternative to plaster model in assessment of space analysis.

    Science.gov (United States)

    Kumar, A Anand; Phillip, Abraham; Kumar, Sathesh; Rawat, Anuradha; Priya, Sakthi; Kumaran, V

    2015-08-01

    Digital three-dimensional models are widely used for orthodontic diagnosis. The purpose of this study was to appraise the accuracy of digital models obtained from computer-aided design/computer-aided manufacturing (CAD/CAM) and cone-beam computed tomography (CBCT) for tooth-width measurements and the Bolton analysis. Digital models (CAD/CAM, CBCT) and plaster model were made for each of 50 subjects. Tooth-width measurements on the digital models (CAD/CAM, CBCT) were compared with those on the corresponding plaster models. The anterior and overall Bolton ratios were calculated for each participant and for each method. The paired t-test was applied to determine the validity. Tooth-width measurements, anterior, and overall Bolton ratio of digital models of CAD/CAM and CBCT did not differ significantly from those on the plaster models. Hence, both CBCT and CAD/CAM are trustable and promising technique that can replace plaster models due to its overwhelming advantages.

  7. Treatment of localized neuropathic pain after disk herniation with 5% lidocaine medicated plaster

    Science.gov (United States)

    Likar, Rudolf; Kager, Ingo; Obmann, Michael; Pipam, Wolfgang; Sittl, Reinhard

    2012-01-01

    Objective To assess treatment with the 5% lidocaine medicated plaster for peripheral neuropathic pain after disk herniation. Study design Case series, single center, retrospective data. Patients and methods Data of 23 patients treated for neuropathic pain with the lidocaine plaster for up to 24 months after a protrusion or prolapse of the cervical, thoracic, or lumbar vertebral disks were retrospectively analyzed. Changes in overall pain intensity, in intensity of different pain qualities and of allodynia and hyperalgesia were evaluated. Results Patients (14 female/nine male, mean age 53.5 ± 10.4 years) presented with radiating pain into the abdomen, back, neck, shoulder, or legs and feet with a mean pain intensity of 8.3 ± 1.5 on the 11-point Likert scale. Mean treatment duration was 7.6 months; 52% of the patients received lidocaine plaster as monotherapy. At the end of the observation, mean overall pain intensity had been reduced to 3.1 ± 1.8. All other parameters also improved. The treatment was well tolerated. Conclusion These results point to a safe and effective treatment approach with 5% lidocaine medicated plaster for localized neuropathic pain related to disk herniation. However, owing to the small sample size, further investigation in a larger-scale controlled trial is warranted. PMID:22973116

  8. [Exposure to hand-arm vibrations in orthopaedic plaster room: risk management].

    Science.gov (United States)

    Lembo, Marco; Lunghi, Alessandro; Leo, Erica; Ritrovato, Matteo; Cannatà, Vittorio; Capussotto, Carlo; Tirabasso, Angelo; Zaffina, Salvatore; Camisa, Vincenzo; Derrico, Pietro; Martella, Mauro; Marchetti, Enrico

    2016-03-24

    In hospitals, the use of vibrating tools, such as oscillating saws to cut plaster, can expose the staff to hand-arm vibrations. The aim of the study was to assess the exposure of workers to vibrations in the plaster room and then  identify the most appropriate  intervention for  prevention and protection to be implemented in order to minimize  exposure and  protect  workers' health, considering different individual hyper-susceptibility conditions. Four different models of plaster saws were examined for the evaluation.  Various measurements were made in normal working conditions of the operators. The values of acceleration and noise detected on the instruments  were  in line with those reported in the literature. The preventive measure adopted (replacing plaster saws currently used in the hospital with similar ones with lower vibration emission) was an adequate means of protection. Health surveillance activities  recorded a higher level of wellbeing, both environmentally and individually and, specifically, an increased protection level for the hyper-susceptibility conditions observed during health checks of exposed personnel  which will be monitored regularly by the Occupational Health Service.

  9. Mineralogical and textural characterization of mortars and plasters from the archaeological site of Barsinia, northern Jordan

    Directory of Open Access Journals (Sweden)

    Mustafa Mohammad AL-Naddaf

    2014-12-01

    Full Text Available Twelve mortar and plaster samples excavated in the archaeological site of Barsinia were mineralogically and petrographically examined by XRay Diffraction (XRD and Stereo and Polarized Light Microscopy, while the total carbonate content was measured using a DietrichFruhling Calcimeter. The physical properties of the samples, such as water uptake under atmospheric pressure and under vacuum, together with density and porosity, were measured. Only twelve samples were available for the purposes of this study: 8 plaster samples and 4 mortar samples. Eleven samples out of the total number of samples were mortars or plasters with lime binder and silica aggregate; calcite and quartz were identified in all of these samples. In most of the samples one or more pozzolanic components were detected; a hydraulic effect therefore exists in practically most of the studied mortars. Excluding the plasters taken from waterbearing constructions such as cisterns, and the mortar sample from the compact floor, the binder content is high; in general, the overall porosity of the studied samples is high. Porosity and petrographic investigation results suggest that the burning temperature of the limestone was low and/or the duration of the combustion was short; such preparation conditions produce a desirable quicklime. Owing to the significant compositional and textural differences between the samples that were reported, there is consequently no suitable general mortar that can be adopted for the restoration of the whole site.

  10. [Toxic mustard plaster dematitis and phototoxic dematitis after application of bergamot oil].

    Science.gov (United States)

    Weisenseel, P; Woitalla, S

    2005-12-15

    Two cases that illustrate the risks attendant on the therapeutic use of natural medications by laypersons are reported. In the first case, the application of a mustard plaster triggered toxic dermatitis. In the second case, a session in a solarium after the external application of bergamot oil resulted in a phototoxic reaction.

  11. Treatment of localized neuropathic pain after disk herniation with 5% lidocaine medicated plaster.

    Science.gov (United States)

    Likar, Rudolf; Kager, Ingo; Obmann, Michael; Pipam, Wolfgang; Sittl, Reinhard

    2012-01-01

    To assess treatment with the 5% lidocaine medicated plaster for peripheral neuropathic pain after disk herniation. Case series, single center, retrospective data. Data of 23 patients treated for neuropathic pain with the lidocaine plaster for up to 24 months after a protrusion or prolapse of the cervical, thoracic, or lumbar vertebral disks were retrospectively analyzed. Changes in overall pain intensity, in intensity of different pain qualities and of allodynia and hyperalgesia were evaluated. Patients (14 female/nine male, mean age 53.5 ± 10.4 years) presented with radiating pain into the abdomen, back, neck, shoulder, or legs and feet with a mean pain intensity of 8.3 ± 1.5 on the 11-point Likert scale. Mean treatment duration was 7.6 months; 52% of the patients received lidocaine plaster as monotherapy. At the end of the observation, mean overall pain intensity had been reduced to 3.1 ± 1.8. All other parameters also improved. The treatment was well tolerated. These results point to a safe and effective treatment approach with 5% lidocaine medicated plaster for localized neuropathic pain related to disk herniation. However, owing to the small sample size, further investigation in a larger-scale controlled trial is warranted.

  12. Microscale electrochemical cell using plaster (CaSO4 as liquid junction

    Directory of Open Access Journals (Sweden)

    Yuthapong Udnan

    2008-10-01

    Full Text Available A microscale apparatus for electrochemical cell in which plaster (CaSO4 was used as liquid junction has been developed. A glass tube (0.5 cm ID x 5.0 cm was used to prepare each half-cell. The potentials of the resulting galvanic cells were measured by a multimetre and were compared to those of the galvanic cells in which agar was used as liquid junction. It was found that the potentials produced by the galvanic cells with plaster as liquid junction are not significantly different from those of the cells with agar as liquid junction and close to the theoretical values. In addition, when the developed apparatus was used for the study of electrolysis of potassium iodide solution, it was found that the electrolytic cell made from the microscale apparatus with plaster liquid junction can distinctly separate the reactions occurring at the anode and the cathode. Moreover, the lifetime of the plaster liquid junction is much greater than that of the agar liquid junction.

  13. Clinical Observation on Prevention of Bronchial Asthma with Plaster on Acupoints

    Institute of Scientific and Technical Information of China (English)

    YU Jin-long; ZHU Han-ting

    2008-01-01

    @@ Bronchial asthma is a most common and chronicillness which often relapses and has no cure at present.Acupuncture has its specific advantage in treatingasthma. The author prevented 29 cases of asthma innon-acute stage of attack with plaster on acupoints.Now it is reported as follows.

  14. Forty Cases of Insomnia Treated by Multi-output Electric Pulsation and Auricular Plaster Therapy

    Institute of Scientific and Technical Information of China (English)

    Liu Weizhe

    2007-01-01

    @@ The writer has treated 40 cases of insomnia by the method of multi-output electric pulsation in combination with auricular plaster therapy (with a seed of Vaccariae segetalis 王不留行 taped tightly to a particular ear point and pressed) and received satisfactory therapeutic effects. A report follows.

  15. Reaction of Liquid Sn-Ag-Cu-Ce Solders with Solid Copper

    Science.gov (United States)

    Chriaštel'Ová, J.; Rízeková Trnková, L.; Pocisková Dimová, K.; Ožvold, M.

    2011-09-01

    Small amounts of the rare-earth element Ce were added to the Sn-rich lead-free eutectic solders Sn-3.5Ag-0.7Cu, Sn-0.7Cu, and Sn-3.5Ag to improve their properties. The microstructures of the solders without Ce and with different amounts (0.1 wt.%, 0.2 wt.%, and 0.5 wt.%) of Ce were compared. The microstructure of the solders became finer with increasing Ce content. Deviation from this rule was observed for the Sn-Ag-Cu solder with 0.2 wt.% Ce, and for the Sn-0.7Cu eutectic alloy, which showed the finest microstructure without Ce. The melting temperatures of the solders were not affected. The morphology of intermetallic compounds (IMC) formed at the interface between the liquid solders and a Cu substrate at temperatures about 40°C above the melting point of the solder for dipping times from 2 s to 256 s was studied for the basic solder and for solder with 0.5 wt.% Ce addition. The morphology of the Cu6Sn5 IMC layer developed at the interface between the solders and the substrate exhibited the typical scallop-type shape without significant difference between solders with and without Ce for the shortest dipping time. Addition of Ce decreased the thickness of the Cu6Sn5 IMC layer only at the Cu/Sn-Ag-Cu solder interface for the 2-s dipping. A different morphology of the IMC layer was observed for the 256-s dipping time: The layers were less continuous and exhibited a broken relief. Massive scallops were not observed. For longer dipping times, Cu3Sn IMC layers located near the Cu substrate were also observed.

  16. SINGLE IMAGE CAMERA CALIBRATION IN CLOSE RANGE PHOTOGRAMMETRY FOR SOLDER JOINT ANALYSIS

    OpenAIRE

    Heinemann, D.; S. Knabner; Baumgarten, D.

    2016-01-01

    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. ...

  17. 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

    Presence of moisture in a printed circuit board (PCB) laminate, typically made of glass fibres reinforced epoxy polymer, significantly influences the electrical functionality in various ways and causes problems during soldering process. This paper investigates the water uptake of laminates coated...... 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...

  18. Factors contributing to the temperature beneath plaster or fiberglass cast material

    Science.gov (United States)

    Hutchinson, Michael J; Hutchinson, Mark R

    2008-01-01

    Background Most cast materials mature and harden via an exothermic reaction. Although rare, thermal injuries secondary to casting can occur. The purpose of this study was to evaluate factors that contribute to the elevated temperature beneath a cast and, more specifically, evaluate the differences of modern casting materials including fiberglass and prefabricated splints. Methods The temperature beneath various types (plaster, fiberglass, and fiberglass splints), brands, and thickness of cast material were measured after they were applied over thermometer which was on the surface of a single diameter and thickness PVC tube. A single layer of cotton stockinette with variable layers and types of cast padding were placed prior to application of the cast. Serial temperature measurements were made as the cast matured and reached peak temperature. Time to peak, duration of peak, and peak temperature were noted. Additional tests included varying the dip water temperature and assessing external insulating factors. Ambient temperature, ambient humidity and dip water freshness were controlled. Results Outcomes revealed that material type, cast thickness, and dip water temperature played key roles regarding the temperature beneath the cast. Faster setting plasters achieved peak temperature quicker and at a higher level than slower setting plasters. Thicker fiberglass and plaster casts led to greater peak temperature levels. Likewise increasing dip-water temperature led to elevated temperatures. The thickness and type of cast padding had less of an effect for all materials. With a definition of thermal injury risk of skin injury being greater than 49 degrees Celsius, we found that thick casts of extra fast setting plaster consistently approached dangerous levels (greater than 49 degrees for an extended period). Indeed a cast of extra-fast setting plaster, 20 layers thick, placed on a pillow during maturation maintained temperatures over 50 degrees of Celsius for over 20

  19. Factors contributing to the temperature beneath plaster or fiberglass cast material

    Directory of Open Access Journals (Sweden)

    Hutchinson Mark R

    2008-02-01

    Full Text Available Abstract Background Most cast materials mature and harden via an exothermic reaction. Although rare, thermal injuries secondary to casting can occur. The purpose of this study was to evaluate factors that contribute to the elevated temperature beneath a cast and, more specifically, evaluate the differences of modern casting materials including fiberglass and prefabricated splints. Methods The temperature beneath various types (plaster, fiberglass, and fiberglass splints, brands, and thickness of cast material were measured after they were applied over thermometer which was on the surface of a single diameter and thickness PVC tube. A single layer of cotton stockinette with variable layers and types of cast padding were placed prior to application of the cast. Serial temperature measurements were made as the cast matured and reached peak temperature. Time to peak, duration of peak, and peak temperature were noted. Additional tests included varying the dip water temperature and assessing external insulating factors. Ambient temperature, ambient humidity and dip water freshness were controlled. Results Outcomes revealed that material type, cast thickness, and dip water temperature played key roles regarding the temperature beneath the cast. Faster setting plasters achieved peak temperature quicker and at a higher level than slower setting plasters. Thicker fiberglass and plaster casts led to greater peak temperature levels. Likewise increasing dip-water temperature led to elevated temperatures. The thickness and type of cast padding had less of an effect for all materials. With a definition of thermal injury risk of skin injury being greater than 49 degrees Celsius, we found that thick casts of extra fast setting plaster consistently approached dangerous levels (greater than 49 degrees for an extended period. Indeed a cast of extra-fast setting plaster, 20 layers thick, placed on a pillow during maturation maintained temperatures over 50 degrees of

  20. High-Temperature Lead-Free Solder Alternatives: Possibilities and Properties

    DEFF Research Database (Denmark)

    and mechanical properties of these potential candidate alloys with respect to the currently used high-lead content solders is made. Finally, the paper presents the superior characteristics as well as some drawbacks of these proposed high-temperature lead-free solder alternatives....... 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...

  1. Research Progress in Solderable Black Pad of Electroless Nickel/Immersion Gold

    Institute of Scientific and Technical Information of China (English)

    Liu Haiping; Li Ning; Bi Sifu; Li Deyu

    2007-01-01

    Electroless nickel/immersion gold (ENIG) technology is widely used as one of the surface final finish for electronics packaging substrate and printed circuit board (PCB), providing a protective, conductive and solderable surface. However, there is a solder joint interfacial brittle fracture (or solderability failure) of using the ENIG coating. The characteristics and the application of ENIG technology were narrated in this paper. The research progress on the solderability failure of ENIG was introduced. The mechanism of "black pad" and the possible measure of eliminating or alleviating the "black pad" were also introduced. The development direction and market prospects of ENIG were prospected.

  2. Creep Behavior of Lead-Free Sn-Ag-Cu + Ni-Ge Solder Alloys

    Science.gov (United States)

    Hidaka, N.; Watanabe, H.; Yoshiba, M.

    2009-05-01

    We developed a new lead-free solder alloy, an Sn-Ag-Cu base to which a small amount of Ni and Ge is added, to improve the mechanical properties of solder alloys. We examined creep deformation in bulk and through-hole (TH) form for two lead-free solder alloys, Sn-3.5Ag-0.5Cu-Ni-Ge and Sn-3.0Ag-0.5Cu, at elevated temperatures, finding that the creep rupture life of the Sn-3.5Ag-0.5Cu-Ni-Ge solder alloy was over three times better than that of the Sn-3.0Ag-0.5Cu solder at 398 K. Adding Ni to the solder appears to make microstructural development finer and more uniform. The Ni added to the solder readily combined with Cu to form stable intermetallic compounds of (Cu, Ni)6Sn5 capable of improving the creep behavior of solder alloys. Moreover, microstructural characterization based on transmission electron microscopy analyses observing creep behavior in detail showed that such particles in the Sn-3.5Ag-0.5Cu-Ni-Ge solder alloy prevent dislocation and movement.

  3. Joining of Bi-2212 high- Tc superconductors and metals using indium solders

    Science.gov (United States)

    Oh, S. Y.; Kim, H. R.; Jeong, Y. H.; Hyun, O. B.; Kim, C. J.

    2007-10-01

    BSCCO tubes can be used as a base material for switching devices such as superconducting fault current limiters (SFCLs) that prevent an electrical problem from occurring in an electrical power system. To apply an BSCCO bulk tube to a switching device, the superconducting tube has to be joined with a metallic part to by the over current to the metal part when the FCL is quenched. In this study, joining between Cu-Ni alloy and BSCCO was accomplished by soldering using In-Sn and In-Bi solders. Additionally, an Sn-Ag-Cu/In-Bi solder was used for the soldering of a different kind. For a better joining of the BSCCO superconductor with the In-Bi solder, the surface of the BSCCO was pre-coated with Ag by electro-plating. From the experiments, an intermetallic compound (IMC) of AgxIny chain was observed to be mainly formed from In-Sn and In-Bi soldering process. In case of the soldering of a different kind, IMC of AgxIny and CuxSny was also developed. Finally, we confirmed that the properties of soldering were enhanced by Sn-Ag-Cu/In-Bi twice-soldering process.

  4. Joining of Bi-2212 high-T{sub c} superconductors and metals using indium solders

    Energy Technology Data Exchange (ETDEWEB)

    Oh, S.Y. [Nuclear Nanomaterials Development Laboratory, Korea Atomic Energy Research Institute (KAERI), 150 Dukjin-dong, Yusong-gu, Daejeon 305-353 (Korea, Republic of); Kim, H.R.; Jeong, Y.H.; Hyun, O.B. [Superconductivity and Applications Group, Korea Electric Power Research Institute (KEPRI), Daejeon 305-380 (Korea, Republic of); Kim, C.J. [Nuclear Nanomaterials Development Laboratory, Korea Atomic Energy Research Institute (KAERI), 150 Dukjin-dong, Yusong-gu, Daejeon 305-353 (Korea, Republic of)], E-mail: cjkim2@kaeri.re.kr

    2007-10-01

    BSCCO tubes can be used as a base material for switching devices such as superconducting fault current limiters (SFCLs) that prevent an electrical problem from occurring in an electrical power system. To apply an BSCCO bulk tube to a switching device, the superconducting tube has to be joined with a metallic part to by the over current to the metal part when the FCL is quenched. In this study, joining between Cu-Ni alloy and BSCCO was accomplished by soldering using In-Sn and In-Bi solders. Additionally, an Sn-Ag-Cu/In-Bi solder was used for the soldering of a different kind. For a better joining of the BSCCO superconductor with the In-Bi solder, the surface of the BSCCO was pre-coated with Ag by electro-plating. From the experiments, an intermetallic compound (IMC) of Ag{sub x}In{sub y} chain was observed to be mainly formed from In-Sn and In-Bi soldering process. In case of the soldering of a different kind, IMC of Ag{sub x}In{sub y} and Cu{sub x}Sn{sub y} was also developed. Finally, we confirmed that the properties of soldering were enhanced by Sn-Ag-Cu/In-Bi twice-soldering process.

  5. An Evaluation of Prototype Circuit Boards Assembled with a Sn-Ag Bi Solder

    Energy Technology Data Exchange (ETDEWEB)

    ARTAKI,I.; RAY,U.; REJENT,JEROME A.; VIANCO,PAUL T.

    1999-09-01

    An evaluation was performed which examined the aging of surface mount solder joints assembled with 91.84Sn-3.33Ag-4.83Bi solder. Defect analysis of the as-fabricated test vehicles revealed excellent solderability, good package alignment, and a minimum number of voids. Continuous DC electrical monitoring of the solder joints did not reveal opens during as many as 10,000 thermal cycles (0 C, 100 C). The solder joints exhibited no significant degradation through 2500 cycles, based upon an absence of microstructural damage and sustained shear and pull strengths of chip capacitors and J-leaded solder joints, respectively. Thermal cycles of 5000 and 10,000 resulted in some surface cracking of the solder fillets and coatings. In a few cases, deeper cracks were observed in the thinner reaches of several solder fillets. There was no deformation or cracking in the solder located in the gap between the package I/O and the circuit board pad nor in the interior of the fillets, both locations that would raise concerns of joint mechanical integrity. A drop in the chip capacitor shear strength was attributed to crack growth near the top of the fillet.

  6. 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.

  7. Diclofenac epolamine medicated plaster in the treatment of minor soft tissue injuries: a multicenter randomized controlled trial.

    Science.gov (United States)

    Li, Chunde; Frangione, Valeria; Rovati, Stefano; Zheng, Qingshan

    2013-09-01

    To investigate the efficacy and safety of a topical plaster containing diclofenac epolamine (DHEP) 1.3% in the treatment of patients with acute minor soft tissue injuries in China. This prospective, randomized, double blind, placebo-controlled study had balanced random assignment to DHEP medicated plaster and placebo plaster. A total of 384 patients, aged 18-74 years, with minor soft tissue injury occurring within 72 hours of study entry were enrolled and randomized. Plasters were applied twice daily for seven consecutive days. Outcomes were assessed in three visits over 7 days, in addition to patients' daily self-assessment and an adverse events follow-up visit on day 21. The primary efficacy endpoint was the mean change from baseline in pain on movement on a 100 mm Visual Analogue Scale (VAS) after 7 days of treatment. Secondary efficacy endpoints included pain on movement day-by-day evaluation, summed pain intensity difference, overall treatment efficacy, rescue medication consumption, and treatment tolerability. Reduction in pain on movement after 7 days of treatment, the primary efficacy endpoint, was statistically significantly greater in the DHEP plaster group than with placebo (reduction in VAS pain scores -53.78 ± 16.96 vs -37.02 ± 18.30 for DHEP vs placebo, p plaster was evident by day 1 and increased progressively throughout the treatment period. Global pain relief and overall treatment efficacy were significantly better with DHEP. Both DHEP and placebo plaster were well tolerated with few adverse events, mostly application site reactions. A medicated plaster containing DHEP applied to the affected site in Chinese patients with minor soft tissue injury, such as sprains, strains and contusions, was significantly more effective than placebo at reducing pain scores. Onset of action was rapid and the DHEP plaster was safe and well tolerated. The main limitation was the use of a subjective, though validated, self-reported VAS to assess the primary endpoint.

  8. Accuracy and reproducibility of linear measurements of resin, plaster, digital and printed study-models.

    Science.gov (United States)

    Saleh, Waleed K; Ariffin, Emy; Sherriff, Martyn; Bister, Dirk

    2015-01-01

    To compare the accuracy and reproducibility of measurements of on-screen three-dimensional (3D) digital surface models captured by a 3Shape R700™ laser-scanner, with measurements made using a digital caliper on acrylic, plaster models or model replicas. Four sets of typodont models were used. Acrylic models, alginate impressions, plaster models and physical replicas were measured. The 3Shape R700™ laser-scanning device with 3Shape™ software was used for scans and measurements. Linear measurements were recorded for selected landmarks, on each of the physical models and on the 3D digital surface models on ten separate occasions by a single examiner. Comparing measurements taken on the physical models the mean difference of the measurements was 0.32 mm (SD 0.15 mm). For the different methods (physical versus digital) the mean difference was 0.112 mm (SD 0.15 mm). None of the values showed a statistically significant difference (p plaster and acrylic models. The comparison of measurements on the physical models showed no significant difference. The 3Shape R700™ is a reliable device for capturing surface details of models in a digital format. When comparing measurements taken manually and digitally there was no statistically significant difference. The Objet Eden 250™ 3D prints proved to be as accurate as the original acrylic, plaster, or alginate impressions as was shown by the accuracy of the measurements taken. This confirms that using virtual study models can be a reliable method, replacing traditional plaster models.

  9. Use of Ekibastuzsk coal ash as a filler for acid resistant plaster

    Energy Technology Data Exchange (ETDEWEB)

    Korsakov, F.F.; Isichenko, I.I.; Kabanov, G.A.

    1981-01-01

    Acid resistant plasters are used extensively at thermal power plants for protection of gas conduits, ash traps with spouts and hydraulic valves, and the internal surfaces of smoke pump housings. The surface being protected is preliminarily cleaned and a No. 16-20 steel grid attached to the surface by electrial welding. In producing the acid resistant plaster, 14-17 parts by weight of sodium silicofluoride are added to 100 parts by weight of sodium water glass; the remainder consists of andesite or diabase meal to the required consistency. The water glass fulfills the role of a binder; the sodium silicofluoride accelerates solidification of the water glass and the andesite and diabase meal serve as fillers. We found, tested in the laboratory and used successfully (under experimental-industrial conditions) a substitute for andesite and diabase meal. This substitute was ash of Ekibastuzsk coal, which was not only comparable to the meal in regard to quality of the acid resistant plaster, but even exceeded andesite and diabase meal in regard to several qualitative indicators. At the present time, a formula is being developed for an acid resistant plaster produced on the basis of water glass, sodium silicofluoride and ash of Ekibastuzsk coal. In order to verify the possibility of using other ashes instead of andesite and diabase meal, we also tested, under laboratory conditions, acid resistant plasters using ash from thermal power plants (TPP's) also burning Karagandinsk, Kuuchekinsk, Kuznetsk and Kansko-Achinsk coals. In compositions produced with polymer binders, Kansko-Achinsk coal ash was one of the best fillers, providing the most favorable physico-mechanical properties of the composition.

  10. Health economic evidence of 5% lidocaine medicated plaster in post-herpetic neuralgia

    Directory of Open Access Journals (Sweden)

    Liedgens H

    2013-11-01

    Full Text Available Hiltrud Liedgens,1 Marko Obradovic,1 Mark Nuijten2 1Grunenthal GmbH, Aachen, Germany; 2Ars Accessus Medica, Amsterdam, the Netherlands Background: Post-herpetic neuralgia (PHN is the most common and most debilitating complication of herpes zoster, and involves considerable associated costs. Objective: This paper presents results from nine health economic studies undertaken in eight European countries that compared lidocaine medicated plaster with gabapentin and/or pregabalin in PHN. It aims to support the increasing need for published cost-effectiveness data for health care decision-making processes in Europe. Methods: All studies were based on a similar core Markov model with data derived from clinical trials, local Delphi panels, and official national price and tariff lists. The main outcome measure was cost per quality-adjusted life year gained; time without pain or intolerable adverse events was also included as a secondary outcome measure. All studies focused on an elderly population of patients with PHN who had insufficient pain relief with standard analgesics and could not tolerate or had contraindications to tricyclic antidepressants. Results: Despite considerable differences in many of the variables used, the results showed remarkable similarity and suggested that use of lidocaine medicated plaster offered cost-savings in many of the countries studied, where it proved a highly cost-effective alternative to both gabapentin and pregabalin. Conclusion: Lidocaine medicated plaster is a cost-effective alternative to gabapentin and pregabalin in the treatment of PHN. These savings are largely the result of the superior safety profile of the lidocaine medicated plaster. Keywords: post-herpetic neuralgia, zoster, cost-effectiveness, lidocaine, plaster

  11. Nano Coated Lead Free Solders for Sustainable Electronic Waste Management

    Directory of Open Access Journals (Sweden)

    K. Arun Vasantha Geethan

    Full Text Available ABSTRACT Lead has been used in a wide range of applications, but in the past decades it became clear that its high toxicity could cause various problems. Studies indicate that exposure to high concentrations of lead can cause harmful damages to humans. To eliminate the usage of lead in electronic products as an initiative towards electronic waste management (e waste, lead free solders were produced with suitable methods by replacing lead. But lead free solders are not preferred as a substitute of lead because they are poor in their mechanical properties such as tensile strength, shear strength and hardness which are ultimately required for a material to resist failure.Nano-Structured materials and coatings offer the potential for Vital improvements in engineering properties based on improvements in physical and mechanical properties resulting from reducing micro structural features by factors of 100 to 1000 times compared to current engineering materials.

  12. Morphology and Shear Strength of Lead-Free Solder Joints with Sn3.0Ag0.5Cu Solder Paste Reinforced with Ceramic Nanoparticles

    Science.gov (United States)

    Yakymovych, A.; Plevachuk, Yu.; Švec, P.; Švec, P.; Janičkovič, D.; Šebo, P.; Beronská, N.; Roshanghias, A.; Ipser, H.

    2016-12-01

    To date, additions of different oxide nanoparticles is one of the most widespread procedures to improve the mechanical properties of metals and metal alloys. This research deals with the effect of minor ceramic nanoparticle additions (SiO2, TiO2 and ZrO2) on the microstructure and mechanical properties of Cu/solder/Cu joints. The reinforced Sn3.0Ag0.5Cu (SAC305) solder alloy with 0.5 wt.% and 1.0 wt.% of ceramic nanoparticles was prepared through mechanically stirring. The microstructure of as-solidified Cu/solder/Cu joints was studied using scanning electron microscopy. The additions of ceramic nanoparticles suppressed the growth of the intermetallic compound layer Cu6Sn5 at the interface solder/Cu and improved the microstructure of the joints. Furthermore, measurements of mechanical properties showed improved shear strength of Cu/composite solder/Cu joints compared to joints with unreinforced solder. This fact related to all investigated ceramic nanoinclusions and should be attributed to the adsorption of nanoparticles on the grain surface during solidification. However, this effect is less pronounced on increasing the nanoinclusion content from 0.5 wt.% to 1.0 wt.% due to agglomeration of nanoparticles. Moreover, a comparison analysis showed that the most beneficial influence was obtained by minor additions of SiO2 nanoparticles into the SAC305 solder alloy.

  13. A microstructural analysis of solder joints from the electronic assemblies of dismantled nuclear weapons

    Energy Technology Data Exchange (ETDEWEB)

    Vianco, P.T.; Rejent, J.A. [Sandia National Labs., Albuquerque, NM (United States). Materials Joining Dept.

    1997-05-01

    MC1814 Interconnection Boxes from dismantled B57 bombs, and MC2839 firing Sets from retired W70-1 warheads were obtained from the Pantex facility. Printed circuit boards were selected from these components for microstructural analysis of their solder joints. The analysis included a qualitative examination of the solder joints and quantitative assessments of (1) the thickness of the intermetallic compound layer that formed between the solder and circuit board Cu features, and (2) the Pb-rich phase particle distribution within the solder joint microstructure. The MC2839 solder joints had very good workmanship qualities. The intermetallic compound layer stoichiometry was determined to be that of Cu6Sn5. The mean intermetallic compound layer thickness for all solder joints was 0.885 mm. The magnitude of these values did not indicate significant growth over the weapon lifetime. The size distribution of the Pb-rich phase particles for each of the joints were represented by the mean of 9.85 {times} 10{sup {minus}6} mm{sup 2}. Assuming a spherical geometry, the mean particle diameter would be 3.54 mm. The joint-to-joint difference of intermetallic compound layer thickness and Pb-rich particle size distribution was not caused by varying thermal environments, but rather, was a result of natural variations in the joint microstructure that probably existed at the time of manufacture. The microstructural evaluation of the through-hole solder joints form the MC2839 and MC1814 components indicated that the environmental conditions to which these electronic units were exposed in the stockpile, were benign regarding solder joint aging. There was an absence of thermal fatigue damage in MC2839 circuit board, through-hole solder joints. The damage to the eyelet solder joints of the MC1814 more likely represented infant mortality failures at or very near the time of manufacture, resulting from a marginal design status of this type of solder joint design.

  14. Archaeomagnetic studies in central Mexico—dating of Mesoamerican lime-plasters

    Science.gov (United States)

    Hueda-Tanabe, Y.; Soler-Arechalde, A. M.; Urrutia-Fucugauchi, J.; Barba, L.; Manzanilla, L.; Rebolledo-Vieyra, M.; Goguitchaichvili, A.

    2004-11-01

    For the first time results of an archaeomagnetic study of unburned lime-plasters from Teotihuacan and Tenochtitlan in central Mesoamerica are presented. Plasters made of lime, lithic clasts and water, appear during the Formative Period and were used for a variety of purposes in floors, sculptures, ceramics and supporting media for mural paintings in the Oaxaca and Maya area. In Central Mexico, grinded volcanic scoria rich in iron minerals is incorporated into the lime-plasters mixture. Samples were selected from two archaeological excavation projects in the Teopancazco residential compound of Teotihuacan and the large multi-stage structure of Templo Mayor in Tenochtitlan, where chronological information is available. The intensity of remanent magnetization (natural remanent magnetization (NRM)) and low-field susceptibility are weak reflecting low relative content of magnetic minerals. NRM directions are well grouped and alternating field demagnetization shows single or two-component magnetizations. Rockmagnetic experiments point to fine-grained titanomagnetites with pseudo-single domain behavior. Anisotropy of magnetic susceptibility (AMS) measurements document a depositional fabric, with normal to free-surface minimum AMS axes. Characteristic mean site directions were correlated to the paleosecular variation curve for Mesoamerica. Data from Templo Mayor reflect recent tilting of the structures. Teopancazco mean site declinations show good correspondence with the reference curve, in agreement with the radiocarbon dating. Dates for four stages of Teotihuacan occupancy based on the study of lime-plasters range from AD 350 to 550. A date for a possible Mazapa occupation around AD 850 or 950 is also suggested based on the archaeomagnetic correlation. The archaeomagnetic record of a plaster floor in Teopancazco differed from the other nearby sites pointing to a thermoremanent magnetization; comparison with the reference curve suggests dates around AD 1375 or 1415. The

  15. Combined thermal, thermodynamic and kinetic modelling for the reliability of high-density lead-free solder interconnections

    OpenAIRE

    Yu, Hao

    2006-01-01

    Continuous miniaturization of electronics devices as well as increasing complexity of soldering metallurgy introduce more and more challenges to the reliability of modern electronics products. Although loading condition plays an important role, the reliability of solder interconnections is ultimately controlled by microstructures' responses to loading. It is therefore of great importance to understand and control the microstructural evolutions of solder interconnections under different loadin...

  16. 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.

  17. 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.

  18. Active soft solder deposition by magnetron-sputter-ion-plating (MSIP)-PVD-process

    Energy Technology Data Exchange (ETDEWEB)

    Lugscheider, E.; Bobzin, K.; Erdle, A

    2004-01-30

    In different technical areas micro electro mechanical systems (M.E.M.S.), e.g. micro pumps, micro sensors, actuators and micro dosage systems are in use today. The components of these M.E.M.S. consist of various materials, which have to be joined. To join materials like ceramics, plastics or metals to a hybrid M.E.M.S., established joining technologies have to be adjusted. For the assembling and mounting of temperature sensible micro components, a low temperature joining process, e.g. transient liquid phase (TLP) bonding or an active soft soldering process can be performed. In this article the deposition of a low melting active soft solder by magnetron-sputter (MS)-PVD deposition with an active substrate cooling will be presented. The substrate temperatures were set and controlled by an additional cooling unit, which was integrated into the sputtering facility. In the performed experiments a substrate temperature range from -40 to +20 deg. C was investigated. The effects of these different substrate temperatures to the microstructure and the soldering suitability of the solder system were investigated by scanning electron microscopy (SEM), nanoindentation and soldering tests. The chemical composition of the deposited solder systems was examined by glow discharge optical spectroscopy (GDOS)-analysis. As a suitable substrate temperature range for deposition -10 to -20 deg. C was detected. Solder systems deposited in this temperature range showed good solder abilities.

  19. Dural reconstruction by fascia using a temperature-controlled CO2 laser soldering system

    Science.gov (United States)

    Forer, Boaz; Vasilyev, Tamar; Brosh, Tamar; Kariv, Naam; Gil, Ziv; Fliss, Dan M.; Katzir, Abraham

    2005-04-01

    Conventional methods for dura repair are normally based on sutures or stitches. These methods have several disadvantages: (1) The dura is often brittle, and the standard procedures are difficult and time consuming. (2) The seal is leaky. (3) The introduction of a foreign body (e.g. sutures) may cause an inflammatory response. In order to overcome these difficulties we used a temperature controlled fiber optic based CO2 laser soldering system. In a set of in vitro experiments we generated a hole of diameter 10 mm in the dura of a pig corpse, covered the hole with a segment of fascia, and soldered the fascia to the edges of the hole, using 47% bovine albumin as a solder. The soldering was carried out spot by spot, and each spot was heated to 65° C for 3-6 seconds. The soldered dura was removed and the burst pressure of the soldered patch was measured. The average value for microscopic muscular side soldering was 194 mm Hg. This is much higher than the maximal physiological pressure of the CSF fluid in the brain, which is 15 mm Hg. In a set of in vivo experiments, fascia patches were soldered on holes in five farm pigs. The long term results of these experiments were very promising. In conclusion, we have developed an advanced technique for dural reconstruction, which will find important clinical applications.

  20. 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.

  1. Development of lead-free solders for high-temperature applications

    DEFF Research Database (Denmark)

    Chidambaram, Vivek

    -temperature applications. Unfortunately, even the substitute technologies that are currently being developed cannot address several critical issues of high-temperature soldering. Therefore, further research and development of high-temperature lead-free soldering is obviously needed. It is hoped that this thesis can serve...... as a valuable source of information to those interested in environmentally conscious electronic packaging....

  2. 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,...

  3. Development of a solder bump technique for contacting a three-dimensional multi electrode array

    NARCIS (Netherlands)

    Frieswijk, T.A.; Frieswijk, T.A.; Bielen, J.A.; Bielen, J.A.; Rutten, Wim; Bergveld, Piet

    1997-01-01

    The application of a solder bump technique for contacting a three-dimensional multi electrode array is presented. Solder bumping (or C4: Controlled Collapse Chip Connections, also called Flip Chip contacting) is the most suitable contacting technique available for small dimensions and large numbers

  4. The automated system for technological process of spacecraft's waveguide paths soldering

    Science.gov (United States)

    Tynchenko, V. S.; Murygin, A. V.; Emilova, O. A.; Bocharov, A. N.; Laptenok, V. D.

    2016-11-01

    The paper solves the problem of automated process control of space vehicles waveguide paths soldering by means of induction heating. The peculiarities of the induction soldering process are analyzed and necessity of information-control system automation is identified. The developed automated system makes the control of the product heating process, by varying the power supplied to the inductor, on the basis of information about the soldering zone temperature, and stabilizing the temperature in a narrow range above the melting point of the solder but below the melting point of the waveguide. This allows the soldering process automating to improve the quality of the waveguides and eliminate burn-troughs. The article shows a block diagram of a software system consisting of five modules, and describes the main algorithm of its work. Also there is a description of the waveguide paths automated soldering system operation, for explaining the basic functions and limitations of the system. The developed software allows setting of the measurement equipment, setting and changing parameters of the soldering process, as well as view graphs of temperatures recorded by the system. There is shown the results of experimental studies that prove high quality of soldering process control and the system applicability to the tasks of automation.

  5. Mechanical properties of FeCo magnetic particles-based Sn-Ag-Cu solder composites

    Science.gov (United States)

    Xu, Siyang; Prasitthipayong, Anya; Pickel, Andrea D.; Habib, Ashfaque H.; McHenry, Michael E.

    2013-06-01

    We demonstrate magnetic nanoparticles (MNPs) in enabling lead-free solder reflow in RF fields and improved mechanical properties that impact solder joint reliability. Here, we report on Sn-Ag-Cu (SAC) alloys. SAC solder-FeCo MNP composites with 0, 1, 2, 3, and 4 wt. % FeCo MNP and the use of AC magnetic fields to achieve localized reflow. Electron microscopy of the as-reflowed samples show a decrease in the volume of Sn dendrite regions as well as smaller and more homogeneously dispersed Ag3Sn intermetallic compounds (IMCs) with increasing MNP concentrations. Mechanical properties of the composites were measured by nanoindentation. In pure solder samples and solder composites with 4 wt. % MNP, hardness values increased from 0.18 GPa to 0.20 GPa and the modulus increased from 39.22 GPa to 71.22 GPa. The stress exponent, reflecting creep resistance, increased from 12.85 of pure solder to 16.47 for solder composites with 4 wt. % MNP. Enhanced mechanical properties as compared with the as-prepared solder joints are explained in terms of grain boundary and dispersion strengthening resulting from the microstructural refinement.

  6. Intermetallic compound layer growth kinetics in non-lead bearing solders

    Energy Technology Data Exchange (ETDEWEB)

    Vianco, P.T.; Kilgo, A.C.; Grant, R.

    1995-04-01

    The introduction of alternative, non-lead bearing solders into electronic assemblies requires a thorough investigation of product manufacturability and reliability. Both of these attributes can be impacted by the excessive growth of intermetallic compound (IMC) layers at the solder/substrate interface. An extensive study has documented the stoichiometry and solid state growth kinetics of IMC layers formed between copper and the lead-free solders: 96.5Sn-3.5Ag (wt.%), 95Sn-5Sb, 100Sn, and 58Bi-42Sn. Aging temperatures were 70--205 C for the Sn-based solders and 55--120 C for the Bi-rich solder. Time periods were 1--400 days for all of the alloys. The Sn/Cu, Sn-Ag/Cu, and Sn-Sb/Cu IMC layers exhibited sub-layers of Cu{sub 6}Sn{sub 5} and Cu{sub 3}Sn; the latter composition was present only following prolonged aging times or higher temperatures. The total layer growth exhibited a time exponent of n = 0.5 at low temperatures and a value of n = 0.42 at higher temperatures in each of the solder/Cu systems. Similar growth kinetics were observed with the low temperature 58Bi-42Sn solder; however, a considerably more complex sub-layer structure was observed. The kinetic data will be discussed with respect to predicting IMC layer growth based upon solder composition.

  7. Generation of Tin(II) Oxide Crystals on Lead-Free Solder Joints in Deionized Water

    Science.gov (United States)

    Chang, Hong; Chen, Hongtao; Li, Mingyu; Wang, Ling; Fu, Yonggao

    2009-10-01

    The effect of the anode and cathode on the electrochemical corrosion behavior of lead-free Sn-Ag-Cu and Sn-Ag-Cu-Bi solder joints in deionized water was investigated. Corrosion studies indicate that SnO crystals were generated on the surfaces of all lead-free solder joints. The constituents of the lead-free solder alloys, such as Ag, Cu, and Bi, did not affect the corrosion reaction significantly. In contrast to lead-free solders, PbO x was formed on the surface of the traditional 63Sn-37Pb solder joint in deionized water. A cathode, such as Au or Cu, was necessary for the electrochemical corrosion reaction of solders to occur. The corrosion reaction rate decreased with reduction of the cathode area. The formation mechanism of SnO crystals was essentially a galvanic cell reaction. The anodic reaction of Sn in the lead-free solder joints occurred through solvation by water molecules to form hydrated cations. In the cathodic reaction, oxygen dissolved in the deionized water captures electrons and is deoxidized to hydroxyl at the Au or Cu cathode. By diffusion, the anodic reaction product Sn2+ and the cathodic reaction product OH- meet to form Sn(OH)2, some of which can dehydrate to form more stable SnO· xH2O crystals on the surface of the solder joints. In addition, thermodynamic analysis confirms that the Sn corrosion reaction could occur spontaneously.

  8. Indium Corporation Introduces New Pb-Free VOC-Free Wave Solder Flux

    Institute of Scientific and Technical Information of China (English)

    2005-01-01

    The Indium Corporation of America has introduced WF-7742 Wave Solder Flux specifically designed to meet the process demands of Pb-Free manufacturing. WF-7742 is a VOC-Free material formulated for Pb-Free wave soldering of surface-mount, mixed-technology and through-holeelectronics assemblies.

  9. Assessment of circuit board surface finishes for electronic assembly with lead-free solders

    Energy Technology Data Exchange (ETDEWEB)

    Ray, U.; Artaki, I.; Finley, D.W.; Wenger, G.M. [Bell Labs., Princeton, NJ (United States). Lucent Technologies; Pan, T.; Blair, H.D.; Nicholson, J.M. [Ford Motor Co., Dearborn, MI (United States); Vianco, P.T. [Sandia National Labs., Albuquerque, NM (United States)

    1996-10-01

    The suitability of various metallic printed wiring board surface finishes was assessed for new technology applications that incorporate assembly with Lead-free solders. The manufacture of a lead-free product necessitates elimination of lead (Pb) from the solder, the circuit board as well as the component lead termination. It is critical however for the selected interconnect Pb-free solder and the corresponding printed wiring board (PWB) and component lead finishes to be mutually compatible. Baseline compatibility of select Pb-free solders with Pb containing PWB surface finish and components was assessed. This was followed by examining the compatibility of the commercially available CASTIN{trademark} (SnAgCuSb) Pb-free solder with a series of PWB metallic finishes: Ni/Au, Ni/Pd, and Pd/Cu. The compatibility was assessed with respect to assembly performance, solder joint integrity and long term attachment reliability. Solder joint integrity and mechanical behavior of representative 50 mil pitch 20I/O SOICs was determined before and after thermal stress. Mechanical pull test studies demonstrated that the strength of SnAgCuSb solder interconnections is notably greater than that of SnPb interconnections.

  10. Wettability study of lead free solder paste and its effect towards multiple reflow

    Directory of Open Access Journals (Sweden)

    Idris Siti Rabiatull Aisha

    2016-01-01

    Full Text Available Nowadays, wafer bumping using solder paste has come into focus as it provides a low cost method. However, since the industries are moving towards lead-free electronic packaging, a new type of no-clean flux was produced specifically for lead-free solder paste. Therefore, this study is used to evaluate the wettability of two different types of no-clean flux onto copper substrate. Besides, its effect towards multiple reflow was also studied. Reflow soldering was conducted for both types of solder paste that contained different type of no-clean flux for up to double reflow. Two different reflow profile was used. The results showed that the Flux A exhibit better soldering performance after first and second reflow soldering. In addition, type of intermetallic compound (IMC found after first reflow remain the same even after second reflow which was Cu-Sn based. This is shows that Flux A manage to control the diffusion process which will finally leads to a better solder joint performance. Nevertheless, mechanical testing should be carried out in order to evaluate the solder joint strength.

  11. [Experimental study on effects of acupoint application with Leima type II plaster on collagen-induced arthritis in rats].

    Science.gov (United States)

    Li, Peng; Fang, Jian-Qiao; Zhou, Ya-Feng

    2011-09-01

    To observe the therapeutic effect of acupoint application with Leima type II plaster on collagen-induced arthritis (CIA) in rats and probe its mechanism. Bovine type II collagen was injected intradermally into the middle line of the back to induce CIA model with 48 Wistar rats. Then the rats were randomly divided into a model control group (group A), a matrix control group (group B), acupoint application group with plaster of low concentration (group C) and high concentration plaster group (group D), 12 rats in each group. Group C and group D were treated with low and high concentration of Leima type II plaster, and "Shenzhu" (GV 12), "Zhiyang" (GV 9) and "Mingmen" (GV 4) were selected, each application for about 15 hours, once each day for 30 days. Group B was used the same method of acupoint application except using non-drug matrix plaster, and group A was not given any treatment. The morphous and the histopathological changes of affection joint were observed. The paw edema volume after 30 days treatment in group C was significantly lower than that in group B (P plaster has a good therapeutic effect on CIA rats and the protective mechanism is related to the reduction of anti-type II collagen antibody level so as to carry out anti-inflammatory effect and immunosuppression.

  12. Efficacy of betamethasone valerate medicated plaster on painful chronic elbow tendinopathy: a double-blind, randomized, placebo-controlled trial.

    Science.gov (United States)

    Frizziero, Antonio; Causero, Araldo; Bernasconi, Stefano; Papalia, Rocco; Longo, Mario; Sessa, Vincenzo; Sadile, Francesco; Greco, Pasquale; Tarantino, Umberto; Masiero, Stefano; Rovati, Stefano; Frangione, Valeria

    2016-01-01

    to investigate the efficacy and safety of a medicated plaster containing betamethasone valerate (BMV) 2.25 mg in patients with chronic elbow tendinopathy. randomized, double-blind, placebo-controlled study with assignment 2:2:1:1 to BMV medicated plaster applied daily for 12 hours, daily for 24 hours or matched placebo. 62 patients aged ≥18 years with chronic lateral elbow tendinopathy were randomized. The primary efficacy variable was pain reduction (VAS) at day 28. Secondary objectives included summed pain intensity differences (SPID), overall treatment efficacy and tolerability. mean reduction in VAS pain score at day 28 was greater in both BMV medicated plaster groups, -39.35±27.69 mm for BMV12-h and -36.91±32.50 mm for BMV24-h, than with placebo, -20.20±27.32 mm. Considering the adjusted mean decreases, there was a statistically significant difference between BMV12-h and placebo (p=0.0110). Global pain relief (SPID) and overall treatment efficacy were significantly better with BMV. BMV and placebo plasters had similar local tolerability and there were few treatment-related adverse events. BMV plaster was significantly more effective than placebo at reducing pain in patients with chronic elbow tendinopathies. The BMV plaster was safe and well tolerated.

  13. Complex of automated equipment and technologies for waveguides soldering using induction heating

    Science.gov (United States)

    Murygin, A. V.; Tynchenko, V. S.; Laptenok, V. D.; Emilova, O. A.; Bocharov, A. N.

    2017-02-01

    The article deals with the problem of designing complex automated equipment for soldering waveguides based on induction heating technology. A theoretical analysis of the problem, allowing to form a model of the «inductor-waveguide» system and to carry out studies to determine the form of inducing wire, creating a narrow and concentrated heat zone in the area of the solder joint. Also solves the problem of the choice of the temperature control means, the information from which is used later to generate the effective management of induction soldering process. Designed hardware complex in conjunction with the developed software system is a system of automatic control, allowing to manage the process of induction heating, to prevent overheating and destruction of the soldered products, improve the stability of induction soldering process, to improve the quality of products, thereby reducing time and material costs for the production.

  14. Optimization of Pb-Free Solder Joint Reliability from a Metallurgical Perspective

    Science.gov (United States)

    Zeng, Kejun; Pierce, Mike; Miyazaki, Hiroshi; Holdford, Becky

    2012-02-01

    To obtain the desired performance of Pb-free packages in mechanical tests, while the solder composition should be carefully selected, the influence of metals dissolved from the soldering pad or under bump metallization (UBM) should also be taken into account. Dissolved metals such as Cu can alter the intermetallic compound (IMC) formation, not only at the local interface but also on the other side of the joint. The high rate of interfacial cracking of Sn-Ag-Cu solder joints on Ni/Au-plated pads is attributed to the high stiffness of the solder and the dual IMC structure of (Cu,Ni)6Sn5 on Ni3Sn4 at the interface. Approaches to avoid this dual IMC structure at the interface are discussed. A rule for selecting the solder alloy composition and the pad surface materials on both sides of the joints is proposed for ball grid array (BGA) packages.

  15. Tensile properties and thermal shock reliability of Sn-Ag-Cu solder joint with indium addition.

    Science.gov (United States)

    Yu, A-Mi; Jang, Jae-Won; Lee, Jong-Hyun; Kim, Jun-Ki; Kim, Mok-Soon

    2012-04-01

    The thermal shock reliability and tensile properties of a newly developed quaternary Sn-1.2Ag-0.5Cu-0.4In (wt%) solder alloy were investigated and compared to those of ternary Sn-Ag-Cu based Pb-free solder alloys. It was revealed that the Sn-1.2Ag-0.5Cu-0.4In solder alloy shows better thermal shock reliability compared to the Sn-1.0Ag-0.5Cu and Sn-3.0Ag-0.5Cu solder alloys. The quaternary alloy has higher strength than Sn-1.0Ag-0.5Cu alloy, and higher elongation than Sn-3.0Ag-0.5Cu alloy. It was also revealed that the addition of indium promotes the formation of Ag3(Sn, In) phase in the solder joint during reflow process.

  16. 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.

  17. A detailed rock-magnetic and archeomagnetic study of lime-plasters from central Mexico

    Science.gov (United States)

    Soler-Arechalde, A. M.; Rodriguez, M.; Ramirez, O.; Gogichaishvili, A.; Caballero-Miranda, C.; Hueda-Tanabe, Y.; Urrutia-Fucugauchi, J.

    2003-04-01

    We carried out a reconnaissance rock-magnetic and archeomagnetic investigations of lime-plasters at some most important pre-Hispanic sites in Central Mexico. Both burned and unburned lime plasters (in total 30 samples) were analyzed from Teotihuacan, Tlatelolco, Santa Cruz Atizapan and Pañhu. The characteristic directions determined in this study are considered to be of primary origin. Thermomagnetic investigation show that the remanence is carried in most cases by magnetite or Ti-poor titanomagnetite. Unblocking temperature spectra and relatively high coercivity point to 'small' pseudo-single domain magnetic structure grains as responsible for remanent magnetization. Single-component, linear demagnetization plots were observed in most of cases. The mean site directions are consistent with the available reference master curve for Mesoamerica.

  18. Can we save a follow up appointment by leaving nylon sutures under plaster for 6 weeks

    Directory of Open Access Journals (Sweden)

    Randeep Aujla

    2010-02-01

    Full Text Available Randeep Aujla, Abhinav Gulihar, Andrew Chandraraj, Graham TaylorOrthopaedic Department, Glenfield Hospital, Groby Road, Leicester, EnglandBackground: The purpose of this study was to highlight the potential resource saving method of leaving nylon sutures under plaster for 6 weeks after forefoot surgery. Methods: We gathered patient data from 72 cases of forefoot surgery over a 5-year period and analyzed the complications encountered. Only patients who required at least 6 weeks of plaster were included.Results: There were two cases of wound infection and one of flap necrosis. The infection rates are comparable to previous studies into forefoot surgery infection rates. There was no difficulty in removing the sutures and scarring was not noted to be a problem.Conclusions: Financial, convenience and time benefits could be obtained if this technique was in common practice.Keywords: elective forefoot surgery, wound infections, wound complications, nylon sutures

  19. The effects of nicotine in dermal plaster on cognitive functions in patients with Alzheimer's disease.

    Science.gov (United States)

    Snaedal, J; Johannesson, T; Jonsson, J E; Gylfadottir, G

    1996-01-01

    Eighteen patients with probable Alzheimer's disease (NINCDS/ADRDA criteria) participated in a placebo-controlled, double-blind study, with a crossover design. The patients had mild or moderate dementia (MMSE = 20.3 +/- 4.6, range 12-28). The trial consisted of two 4-week periods with a 2-week washout period in between. Nicotine was given in the form of dermal plasters. Most of the patients tolerated the highest doses of 21 mg nicotine/24 h, but some received 14 mg/24 h. The effect was monitored with tests of short-term memory, verbal fluency, attention and psychomotor speed. Nicotine was also determined in the blood. Short-term memory improved significantly after 4 weeks of treatment, both on nicotine and placebo (p nicotine applied in the form of dermal plasters is of any significance in the treatment of memory deficits in patient with Alzheimer's disease.

  20. Can foot compression under a plaster cast prevent deep-vein thrombosis during lower limb immobilisation?

    Science.gov (United States)

    Domeij-Arverud, E; Latifi, A; Labruto, F; Nilsson, G; Ackermann, P W

    2013-09-01

    We hypothesised that adjuvant intermittent pneumatic compression (IPC) beneath a plaster cast would reduce the risk of deep-vein thrombosis (DVT) during post-operative immobilisation of the lower limb. Of 87 patients with acute tendo Achillis (TA) rupture, 26 were prospectively randomised post-operatively after open TA repair. The treatment group (n = 14) received two weeks of IPC of the foot for at least six hours daily under a plaster cast. The control group (n = 12) had no additional treatment. At two weeks post-operatively all patients received an orthosis until follow-up at six weeks. At two and six weeks the incidence of DVT was assessed using colour duplex sonography by two ultrasonographers blinded to the treatment. Two patients withdrew from the study due to inability to tolerate IPC treatment. An interim analysis demonstrated a high incidence of DVT in both the IPC group (9 of 12, 75%) and the controls (6 of 12, 50%) (p = 0.18). No significant differences in incidence were detected at two (p = 0.33) or six weeks (p = 0.08) post-operatively. Malfunction of the IPC leading to a second plaster cast was found to correlate with an increased DVT risk at two weeks (ϕ = 0.71; p = 0.019), leading to a premature abandonment of the study. We cannot recommend adjuvant treatment with foot IPC under a plaster cast for outpatient DVT prevention during post-operative immobilisation, owing to a high incidence of DVT related to malfunctioning of this type of IPC application.

  1. Who should answer the question: "Can I drive with this plaster cast?".

    Science.gov (United States)

    Gandhi, M J; Freitas, D; Lewis, M; Bolton, L; Bhasin, S; Leonard, D; Marsh, A

    2014-02-01

    The application of a plaster cast is known to affect driving ability, but patients continue to drive. The individuals and authorities involved in assessing driving safely include doctors, the Driver and Vehicle Licensing Agency (DVLA), police, insurance companies, and patients, but it is unclear who should take responsibility for the advice given, especially in the event of an accident. We contacted senior plaster technicians in 348 hospitals in the UK. We recorded their responses regarding advice given to patients on driving in specific casts. Sixteen motor insurance companies and 40 police forces were also contacted in order to canvass their opinions. 188 technician interviews (response rate 54%) were conducted. Only 10% of respondents offered advice unprompted; an average of 48% of patients asked for advice. 88% of respondents referred patients to their motor insurance companies, and also to the DVLA (11.7%), doctor (10.6%), or police (5.9%). Only 20.2% of plaster rooms provided written information. All insurance companies would insure patients provided the doctor had not explicitly objected to driving, but there was no consensus amongst the responses received from police. In the event of an accident after the treating doctor had advised against driving, insurance companies were likely to invalidate the policy, and the police would seek penalty punishment or prosecution. Although doctors are not specifically trained to assess the ability of patients to drive, insurance companies and police forces place the responsibility on doctors to advise patients. Since current evidence suggests plaster casts can impair driving ability, we suggest patients should be advised not to drive. Patients accept all responsibility if they continue to drive after receiving this specific advice and understanding its implications. Copyright © 2013 Royal College of Surgeons of Edinburgh (Scottish charity number SC005317) and Royal College of Surgeons in Ireland. Published by Elsevier

  2. Quality of Plaster Molding for Distal Radius Fractures Is Improved Through Focused Tuition of Junior Surgeons.

    Science.gov (United States)

    Ramoutar, Darryl N; Silk, Robert; Rodrigues, Jeremy N; Hatton, Mark

    2014-08-01

    Successful nonoperative management of distal radius fractures requires an adequately reduced fracture held in a well-molded cast. The purpose of this study was to determine whether a targeted teaching session to the same group of junior doctors led to objective improvement in fracture reduction and plaster molding and hence a decrease in the redisplacement of these fractures. Retrospective review. Level I academic trauma center. A retrospective review of all dorsally angulated distal radius fractures treated in plaster that presented to our plaster room over a 4-week period (group 1, n = 52). This was followed by the intervention and a subsequent 4-week prospective review (group 2, n = 36). Radiographs were reviewed before manipulation, after manipulation, and at follow-up by a single senior orthopaedic trainee using predetermined criteria. A targeted teaching session on fracture reduction and cast molding to the same group of junior doctors involved in managing all these cases. Adequate fracture reduction, plaster molding, redisplacement, and further intervention before and after the targeted intervention. In group 1, 85% had adequate fracture reduction but only 36% showed adequate molding. This was improved in group 2%-94% adequate reduction and 65% adequate molding (P = 0.022). The rate of redisplacement was improved from 65% to 44% in group 2. In both groups, the rate of redisplacement was around 20% for adequately reduced and molded fractures, compared with around 90% for adequately reduced but inadequately molded cases (P < 0.001). The rate of further intervention improved from 27% to 8% (P = 0.052). We recommend that specific teaching focusing on fracture reduction and molding techniques is included in orthopaedic juniors' induction teaching or as a separate session. Therapeutic Level III. See Instructions for Authors for a complete description of levels of evidence.

  3. Effect of lipidmicrosphere prostaglandin combined with Shengji plaster on bedsore healing in III and IV degree

    Institute of Scientific and Technical Information of China (English)

    Su-Fang Gao; Qing-Fu Song; Shu-Ping Gao

    2016-01-01

    Objective:To observe the effect of lipidmicrosphere prostaglandin (Lipo PGE1) combined with Shengji plaster on the bedsore healing.Methods: A total of 100 patients with bedsores in III and IV degree who were admitted in our hospital from January, 2013 to January, 2015 were included in the study and divided into the observation group and the control group with 50 cases in each group according to different treatment protocols. The blood glucose, infection, and blood pressure in the two groups were effectively controlled. The patients in the observation group were given intravenous drip of Lipo PGE1 and external application of Shengji plaster, while the patients in the control group were given intravenous drip of Chuanxiongqin injection and external application of Shengji plaster. Four-week treatment was regarded as one course. The specimens on the wound surface of bedsores 1, 2, 3, and 4 weeks after treatment were collected. SABC developing method was used to observe the blood capillary density value (/10 HP). TcPO2 1 cm around the wound surface and the skin temperature were measured.Results:The blood capillary density values 1, 2, 3, and 4 weeks after treatment in the observation group were significantly higher than those in the control group (P<0.05). The bedsore wound surface skin temperature 2, 4, 6, and 8 h after medication in the observation group was significantly lower than that in the control group (P<0.05), while TcPO2 was significantly higher than that in the control group (P<0.05).Conclusions: Lipo PGE1 combined with Shengji plaster can effectively improve the blood circulation on the wound surface of bedsores, and promote the bedsore healing.

  4. The plaster plate becomes a air-conditioner; La plaque de platre se fait climatiseur

    Energy Technology Data Exchange (ETDEWEB)

    Lucat, Th.

    2005-09-01

    BASF company, in association with Knauf, has developed a plaster plate capable to regulate the indoor temperature of a room during summer time. A paraffin-based (wax) phase change material, named Micronal, is included in the plater to store energy during the day and to release it during the night. The lifetime of the phase change material is at least 30 years without loss of efficiency. Short paper. (J.S.)

  5. Treatment of localized neuropathic pain after disk herniation with 5% lidocaine medicated plaster

    OpenAIRE

    Likar, Rudolf; Kager, Ingo; Obmann,; Pipam, Wolfgang; Sittl,Reinhard

    2012-01-01

    Rudolf Likar,1 Ingo Kager,1 Michael Obmann,1 Wolfgang Pipam,1 Reinhard Sittl21Department of Anesthesiology and Intensive Care, Klagenfurt Hospital, Klagenfurt, Austria; 2Department of Anesthesiology, Interdisciplinary Pain Center, University Hospital Erlangen, Erlangen, GermanyObjective: To assess treatment with the 5% lidocaine medicated plaster for peripheral neuropathic pain after disk herniation.Study design: Case series, single center, retrospective data.Patients and methods: Data of 23 ...

  6. Development of Innovative Aerogel Based Plasters: Preliminary Thermal and Acoustic Performance Evaluation

    Directory of Open Access Journals (Sweden)

    Cinzia Buratti

    2014-09-01

    Full Text Available The thermal and acoustic properties of innovative insulating systems used as building coatings were investigated: Granular silica aerogel was mixed with natural plaster in different percentages. This coating solution is transpiring and insulating, thanks to the use of a natural lime coat and aerogel, a highly porous light material with very low thermal conductivity. The thermal conductivity of the proposed solution was evaluated by means of a Heat Flow meter apparatus (EN ISO 12667, considering different percentages of aerogel. The natural plaster without aerogel has a thermal conductivity of about 0.50 W/m K; considering a percentage of granular aerogel of about 90% in volume, the thermal conductivity of the insulating natural coating falls to 0.050 W/m K. Increasing the percentage of granular aerogel, a value of about 0.018–0.020 W/m K can be reached. The acoustic properties were also evaluated in terms of the acoustic absorption coefficient, measured by means of a Kundt’s Tube (ISO 10534-2. Two samples composed by a plasterboard support, an insulation plaster with aerogel (thicknesses 10 mm and 30 mm respectively and a final coat were assembled. The results showed that the absorption coefficient strongly depends on the final coat, so the aerogel-based plaster layer moderately influences the final value. The application of this innovative solution can be a useful tool for new buildings, but also for the refurbishment of existing ones. This material is in development: until now, the best value of the thermal conductivity obtained from manufacturers is about 0.015 W/m K.

  7. Observations on the Efficacy of Auricular-plaster Therapy plus Medicine in Treating Heroin Addiction

    Institute of Scientific and Technical Information of China (English)

    王泽涛; 袁宜勤; 王军; 罗杰坤

    2006-01-01

    Objective:To investigate the curative effect of auricular-plaster therapy on heroin addiction. Methods: Sixty cases of heroin addiction were treated by auricular-plaster therapy in cooperation with methadone and another 60 cases with methadone as a control. The treatment lasted 10 days. Results and conclusion: The results showed that the curative effect of auricular-plaster therapy plus methadone on heroin addiction was significantly better than that of methadone in the control group(P<0.01). The rate of drug relapse was also significantly lower in the former(P<0.01). It is considered that auricular-plaster therapy in cooperation with methadone is now an ideal therapeutic method for drug withdrawal.%目的:观察耳穴贴压治疗海洛因依赖的疗效.方法:耳穴贴压配合西药美沙酮治疗海洛因依赖60例,并与美沙酮治疗60例作对照,临床戒毒观察10 d.结果与结论:结果表明,耳穴贴压配合西药美沙酮戒毒疗效明显优于对照组美沙酮的戒毒疗效(P《0.01),其复吸率也低(P《0.01).认为耳穴贴压配合西药美沙酮戒毒是目前比较理想的戒毒治疗方法.

  8. Study on Sn-Zn Solder Used in Cu-Al Soldering%用于铜铝焊接的锡锌焊料研究

    Institute of Scientific and Technical Information of China (English)

    倪广春; 张浩; 韩敏

    2013-01-01

    Lead-free electronic products led the development of lead-free solder technology. Taking cost factors into account, some copper material has been replaced by aluminum material. When ordinary Sn-Cu and Sn-Ag-Cu solder are used in soldering of Cu-Al, there is the electrochemical corrosion problems. So Sn-Zn solder is used for Cu-Al soldering. However, the joints of Sn-Zn solder are brittle and easy to crack. Focus on problems in Cu-Al soldering joint of electrical and electronic devices, put forward Sn-Zn-X alloy soldering materials, did a large number of experiments, and achieved good results.%电子产品无铅化的推广带动了无铅焊料技术的发展,考虑到成本因素,部分铜材已被铝材取代。普通的锡铜系和锡银铜系焊料在铜铝焊接时,存在电化学腐蚀问题,因此多用锡锌焊料进行焊接。但锡锌焊料的焊点脆,存在易开裂的问题。针对电工电子器件铜铝焊接点存在的问题,提出了Sn一Zn一X多元合金焊接材料,并做了大量实验,取得很好的效果。

  9. 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.)

  10. Prediction of drilling micro-hole in CO{sub 2} laser irradiated sticking plaster

    Energy Technology Data Exchange (ETDEWEB)

    Rao Zhiming; Lu Yanzhao [Wuhan National Laboratory for Optoelectronic, the College of Optoelectronic Science and Engineering, Huazhong University of Science and Technology, Wuhan 430074, Hubei (China); Wu Tao [School of Science, Wuhan Institute of Technology, Wuhan 430073 (China); Du Jianqiang, E-mail: raozm24@163.com [Depart of Computer Science, Jiangxi University of Traditional Chinese Medicine, Nanchang 330004, Jiangxi (China)

    2011-02-01

    This paper reports a simulation model of drilling micro-hole in sticking plaster heated with a 1064 nm continuous CO{sub 2} laser beam. Laser spot sizes ranged from 0.1 to 0.2mm diameter with axial irradiance power levels of 25-100W. To apply software Ansys, the measured steady-state surface temperature is calculated to rise with both increasing beam power and incident laser irradiance. For temperatures above 450 deg. C, sticking plaster vaporized into ventilation hole, and the size of ventilation hole 0.15mm diameter spent 1.7ms heated with laser power lever of 100W with the size of spot 0.15mm diameter, in good accordance with reported in earlier experiments studies. Similarly, the size of ventilation holes changed with beam power and laser spot diameter. These results show that software Ansys can be used to predict drilling micro-hole in CO{sub 2} laser irradiated sticking plaster and the result of simulation can guide to laser drilling experiments.

  11. Dilatometric studies of plaster sandmix in raw and heat treated state

    Directory of Open Access Journals (Sweden)

    M. Pawlak

    2008-10-01

    Full Text Available Results of dilatometric studies of bounded plaster sandmix applied in precision pressure below atmospheric casting, are presented in this paper. Sandmix composed of half-hydrate α-CaSO4·2H2O with different parts of silica SiO2 was a subject of investigations. Silica is a factor weakening the influence of phase transformations on total distortion of the mould during heating and thus influences the accuracy of prepared cast. Experimental moulders of dimensions 7x35 made of plaster sandmix with silica fraction equal 30; 40; 50; 60 and 70% were used during studies. Sandmix was tested in raw state and after heat treatment changing the α-half hydrate into anhydrite II (CaSO4. It was demonstrated that addition of the silica at level about 50% influences most advantageously on dimension changes of heated sandmix by lowering dilatations 3 times in comparison with sandmix composed of pure α-half hydrate. The transformation of plaster structure into anhydrite II is also important - the shrinkability phase disappears and expansion similar to linear-like appears. It was determined that it is possible to obtain sandmix of small, stabile distortion on the way of appropriate selection of components and heat treatment parameters what improves dimensional and shape accuracy limits of the cast and significantly limits internal stresses in the mould eliminating risk of its cracking.

  12. Does the contact time of alginate with plaster cast influence its properties?

    Directory of Open Access Journals (Sweden)

    Mariana Marquezan

    2012-06-01

    Full Text Available The aim of this study was to verify the influence of the time of contact between alginate and gypsum after the modeling procedure on the properties of the plaster cast, such as surface detail, dimensional stability and microhardness. Thirty cylindrical specimens of orthodontic gypsum Type III were made by means of impressions of a stainless steel master model which had five reference lines in the upper surface. The samples were divided into two groups: Group 1 (G1 - with time of contact of 1 hour; and Group 2 (G2 - 12 hours of contact. All the specimens were stored up to 48 hours until they underwent laboratory testing. Surface detail and dimensional stability were tested by one calibrated examiner using a visual analysis and a profilometer (Profile Projector Nikon model 6C, Nikon Corporation, Tokyo, Japan, respectively, to evaluate the quality of reproduction of the lines and the distances between them. The microhardness was determined for each sample by making six indentations with a Vickers diamond pyramid indenter (Buehler, Lake Bluff, USA under a load of 100 gF for 15 s. The results showed significant difference (P £ 0.05 between groups in two of the three properties examined: surface detail and microhardness, which decreased as the time of contact rose. The 12-hour time of contact between alginate and the plaster cast is not recommended because it influences the quality of the plaster cast.

  13. Does the contact time of alginate with plaster cast influence its properties?

    Directory of Open Access Journals (Sweden)

    Mariana Marquezan

    Full Text Available The aim of this study was to verify the influence of the time of contact between alginate and gypsum after the modeling procedure on the properties of the plaster cast, such as surface detail, dimensional stability and microhardness. Thirty cylindrical specimens of orthodontic gypsum Type III were made by means of impressions of a stainless steel master model which had five reference lines in the upper surface. The samples were divided into two groups: Group 1 (G1 - with time of contact of 1 hour; and Group 2 (G2 - 12 hours of contact. All the specimens were stored up to 48 hours until they underwent laboratory testing. Surface detail and dimensional stability were tested by one calibrated examiner using a visual analysis and a profilometer (Profile Projector Nikon model 6C, Nikon Corporation, Tokyo, Japan, respectively, to evaluate the quality of reproduction of the lines and the distances between them. The microhardness was determined for each sample by making six indentations with a Vickers diamond pyramid indenter (Buehler, Lake Bluff, USA under a load of 100 gF for 15 s. The results showed significant difference (P £ 0.05 between groups in two of the three properties examined: surface detail and microhardness, which decreased as the time of contact rose. The 12-hour time of contact between alginate and the plaster cast is not recommended because it influences the quality of the plaster cast.

  14. Effect of Shengji Yuhong plaster on the wound healing after anal fistula surgery

    Institute of Scientific and Technical Information of China (English)

    Jin-Zhong Liu; Ma Li

    2016-01-01

    Objective:To observe the effect of Shengji Yuhong plaster on the wound healing after anal fistula surgery.Methods:A total of 120 patients with anal fistula who were admitted in our hospital from January, 2011 to December, 2013 for operation were included in the study and randomized into the observation group and the control group with 50 cases in each group after operation. The patients in the observation group were given external application of Shengji Yuhong plaster, while the patients in the control group were given vaselinum ribbon gauze. The patients in the two groups were given 3-week treatment. The wound area, granulation form, healing rate, healing time, and adverse reactions 1, 2, 3 weeks after operation in the two groups were compared.Results:The wound area 1, 2, 4 weeks after operation in the observation group was significantly less than that in the control group (P<0.05). The granulation form score was significantly lower than that in the control group (P<0.05). The wound repairing rate and the total effective rate were significantly higher than those in the control group (P<0.05), and the average healing time was significantly faster than that in the control group (P<0.05). Conclusions:Shengji Yuhong plaster can significantly shorten the wound healing time in patients after anal fistula surgery and is beneficial for the postoperative rehabilitation.

  15. Comparison of virtual and manual tooth setups with digital and plaster models in extraction cases.

    Science.gov (United States)

    Im, Joon; Cha, Jung-Yul; Lee, Kee-Joon; Yu, Hyung-Seog; Hwang, Chung-Ju

    2014-04-01

    The aim of this study was to compare the virtual and manual tooth setups with digital and plaster models in extraction cases by measuring various occlusal parameters and applying the American Board of Orthodontics objective grading system. Linear intra-arch and interarch dimensions (arch width and length, perimeter, overjet, and overbite), angular variables (tip, torque, and rotation), and American Board of Orthodontics objective grading system scores obtained from a digital virtual setup model were compared with those from a plaster model setup. The digital virtual setup model resulted in smaller arch perimeters than did the plaster setup model by 2.20 mm in the maxillary arch (P overjet (P overjet, occlusal contact, and total score (P <0.01) were required for the digital than for the manual setup model. Digital and manual setups lead to similar measurements for intra-arch and interarch occlusal variables. However, because of the possibility of collision on proximal and occlusal contact, delicate adjustments in proximal and occlusal contacts are required. Copyright © 2014 American Association of Orthodontists. Published by Mosby, Inc. All rights reserved.

  16. The potential role of cattail-reinforced clay plaster in sustainable building

    Directory of Open Access Journals (Sweden)

    G. Georgiev

    2014-06-01

    Full Text Available Sustainable development is a key goal in town and country planning, as well as in the building industry. The main aims are to avoid inefficient land use, to improve the energy efficiency of buildings and, thus, to move towards meeting the challenges of climate change. In this article we consider how the use of a traditional low-energy building material, namely clay, might contribute. Recent research has identified a promising connection between the reinforcement of clay for internal wall plastering with fibres from the wetland plant Typha latifolia (cattail and the positive environmental effects of cultivating this species. If large quantities of Typha fibres were to be used in building, the need for cultivation of the plant would increase and create new possibilities for the renaturalisation of polluted or/and degraded peatlands. We explore the topic first on the basis of literature, considering the suitability of Typha for this application and possibilities for its sustainable cultivation, as well as implications for the life cycle analyses of buildings in which it is used. We then report (qualitatively the results of testing different combinations of clay with natural plant (straw and cattail fibres for their suitability as a universal plaster, which demonstrate clearly the superior properties of Typha fibres as a reinforcement material for clay plaster mortars.

  17. 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...

  18. Pb-free Sn-Ag-Cu ternary eutectic solder

    Energy Technology Data Exchange (ETDEWEB)

    Anderson, I.E.; Yost, F.G.; Smith, J.F.; Miller, C.M.; Terpstra, R.L.

    1996-06-18

    A Pb-free solder includes a ternary eutectic composition consisting essentially of about 93.6 weight % Sn-about 4.7 weight % Ag-about 1.7 weight % Cu having a eutectic melting temperature of about 217 C and variants of the ternary composition wherein the relative concentrations of Sn, Ag, and Cu deviate from the ternary eutectic composition to provide a controlled melting temperature range (liquid-solid ``mushy`` zone) relative to the eutectic melting temperature (e.g. up to 15 C above the eutectic melting temperature). 5 figs.

  19. Imaging and Analysis of Void-defects in Solder Joints Formed in Reduced Gravity using High-Resolution Computed Tomography

    Science.gov (United States)

    Easton, John W.; Struk, Peter M.; Rotella, Anthony

    2008-01-01

    As a part of efforts to develop an electronics repair capability for long duration space missions, techniques and materials for soldering components on a circuit board in reduced gravity must be developed. This paper presents results from testing solder joint formation in low gravity on a NASA Reduced Gravity Research Aircraft. The results presented include joints formed using eutectic tin-lead solder and one of the following fluxes: (1) a no-clean flux core, (2) a rosin flux core, and (3) a solid solder wire with external liquid no-clean flux. The solder joints are analyzed with a computed tomography (CT) technique which imaged the interior of the entire solder joint. This replaced an earlier technique that required the solder joint to be destructively ground down revealing a single plane which was subsequently analyzed. The CT analysis technique is described and results presented with implications for future testing as well as implications for the overall electronics repair effort discussed.

  20. Treatment of allergic rhinitis with acupoint herbal plaster: an oligonucleotide chip analysis.

    Science.gov (United States)

    Shiue, Horng-Sheng; Lee, Yun-Shien; Tsai, Chi-Neu; Chang, Hen-Hong

    2016-11-04

    Allergic rhinitis is regarded as an imbalanced Th1/Th2 cell-mediated response. The present study used microarray analysis to compare gene expression levels between allergic rhinitis patients before and after a series of acupoint herbal plaster applications. In this experimental pilot study, volunteers experiencing sneezing, runny nose, and congestion for more than 9 months in the year following initial diagnoses were included after diagnostic confirmation by otolaryngologists to exclude patients with sinusitis and nasal polyps. Patients with persistent allergic rhinitis each received four acupoint herbal plaster treatments applied using the moxibustion technique. Clinical outcomes were evaluated using the Rhinitis Quality of Life Questionnaire (RQLQ). Peripheral blood samples were analyzed using an ImmunoCAP Phadiatop test, and patients were classified as phadiatop (Ph)-positive or -negative. Microarray results were analyzed for genes that were differentially expressed between (1) Ph-positive and -negative patients treated with herbal plaster; and (2) before and after herbal plaster treatment in the Ph-positive patient group. Unsupervised and supervised methods were used for gene-expression data analysis. Nineteen Ph-positive and four Ph-negative participants with persistent allergic rhinitis were included in the study. RQLQ results indicated that the 19 Ph-positive volunteers experienced improvement in six of seven categories following acupoint herbal plaster treatments, whereas the four Ph-negative participants reported improvement in only two categories. Hierarchical clustering and principle component analysis of the gene expression profiles of Ph-positive and -negative participants indicated the groups exhibited distinct physiological responses to acupoint herbal treatment. Evaluation of gene networks using MetaCore identified that the "Immune response_IL-13 signaling via JAK-STAT" and the "Inflammation_Interferon signaling" were down- and up

  1. Estimates of inhalation doses resulting from the possible use of phospho-gypsum plaster-board in Australian homes.

    Science.gov (United States)

    O'Brien, R S; Peggie, J R; Leith, I S

    1995-04-01

    Current materials used as internal lining in Australian buildings are based on natural gypsum of low radium content. A study was carried out to estimate the contribution to the annual effective dose due to airborne contamination from chemical by-product gypsum plaster-board of higher radium content if it were used as an internal lining. The 226Ra content and 222Rn exhalation rate were measured for several samples of the plaster-board, and the behavior of 222Rn and its progeny (218Po, 214Pb, 214Bi, and 214Po) in a typical building was modeled numerically, using the results of the exhalation rate measurements as input. For building ventilation rates greater than approximately 0.5 air changes per hour, the contribution to the total annual effective dose from inhalation of 222Rn and its progeny exhaled from the phospho-gypsum plaster-board is estimated to be below 1 mSv. This contribution is reduced if the surface of the plaster-board is coated with paint or cardboard, or if the very fine particles are removed from the phospho-gypsum during manufacture of the plaster-board. The effective doses arising from dust generation during the installation of the plaster-board are also estimated to be below 1 mSv. The recommended action level of 200 Bq m-3 for radon in air in Australia corresponds to an annual effective dose of approximately 6 mSv. The study indicates that the suggested acceptable level of 185 Bq kg-1 for the 226Ra concentration in the plaster-board may be too restrictive under Australian conditions.

  2. Laser ablative fluxless soldering (LAFS): 60Sn-40Pb solder wettability tests on laser cleaned OFHC copper substrates

    Energy Technology Data Exchange (ETDEWEB)

    Peebles, H. C.; Keicher, D. M.; Hosking, F. M.; Hlava, P. F.; Creager, N. A.

    1991-01-01

    OFHC copper substrates, cleaned by laser ablation under argon and helium gas, were tested for solder wettability by 60Sn-40Pb using an area-of-spread method. The wettability of copper surfaces cleaned under both argon and helium gas was found to equal or exceed the wettability obtained on this surface in air using a standard RMA flux. The area of spread on copper substrates cleaned under helium was eight times larger than the area of spread of substrates cleaned under argon. The enhanced spreading observed on the substrates cleaned under helium gas was found to be due to surface roughness. 11 refs., 8 figs., 2 tabs.

  3. Detection of micro solder balls using active thermography and probabilistic neural network

    Science.gov (United States)

    He, Zhenzhi; Wei, Li; Shao, Minghui; Lu, Xingning

    2017-03-01

    Micro solder ball/bump has been widely used in electronic packaging. It has been challenging to inspect these structures as the solder balls/bumps are often embedded between the component and substrates, especially in flip-chip packaging. In this paper, a detection method for micro solder ball/bump based on the active thermography and the probabilistic neural network is investigated. A VH680 infrared imager is used to capture the thermal image of the test vehicle, SFA10 packages. The temperature curves are processed using moving average technique to remove the peak noise. And the principal component analysis (PCA) is adopted to reconstruct the thermal images. The missed solder balls can be recognized explicitly in the second principal component image. Probabilistic neural network (PNN) is then established to identify the defective bump intelligently. The hot spots corresponding to the solder balls are segmented from the PCA reconstructed image, and statistic parameters are calculated. To characterize the thermal properties of solder bump quantitatively, three representative features are selected and used as the input vector in PNN clustering. The results show that the actual outputs and the expected outputs are consistent in identification of the missed solder balls, and all the bumps were recognized accurately, which demonstrates the viability of the PNN in effective defect inspection in high-density microelectronic packaging.

  4. Enhanced laser tissue soldering using indocyanine green chromophore and gold nanoshells combination.

    Science.gov (United States)

    Khosroshahi, Mohammad E; Nourbakhsh, Mohammad S

    2011-08-01

    Gold nanoshells (GNs) are new materials that have an optical response dictated by the plasmon resonance. The wavelength at which the resonance occurs depends on the core and shell sizes. The purposes of this study were to use the combination of indocyanine green (ICG) and different concentration of gold nanoshells for skin tissue soldering and also to examine the effect of laser soldering parameters on the properties of repaired skin. Two mixtures of albumin solder and different combinations of ICG and gold nanoshells were prepared. A full thickness incision of 2 × 20 mm(2) was made on the surface and after addition of mixtures it was irradiated by an 810 nm diode laser at different power densities. The changes of tensile strength (σ(t)) due to temperature rise, number of scan (Ns), and scan velocity (Vs) were investigated. The results showed at constant laser power density (I), σ(t) of repaired incisions increases by increasing the concentration of gold nanoshells in solder, Ns, and decreasing Vs. It was demonstrated that laser soldering using combination of ICG + GNs could be practical provided the optothermal properties of the tissue are carefully optimized. Also, the tensile strength of soldered skin is higher than skins that soldered with only ICG or GNs. In our case, this corresponds to σ(t) = 1800 g cm(-2) at I ∼ 47 Wcm(-2), T ∼ 85 [ordinal indicator, masculine]C, Ns = 10, and Vs = 0.3 mms(-1).

  5. A microstructural study of creep and thermal fatigue deformation in 60Sn-40Pb solder joints

    Energy Technology Data Exchange (ETDEWEB)

    Tribula, D.

    1990-06-02

    Thermal fatigue failures of solder joints in electronic devices often arise from cyclic shear strains imposed by the mismatched thermal expansion coefficients of the materials that bind the joint as temperature changes are encountered. Increased solder joint reliability demands a fundamental understanding of the metallurigical mechanisms that control the fatigue to design accurate accelerated probative tests and new, more fatigue resistant solder alloys. The high temperatures and slow strain rates that pertain to thermal fatigue imply that creep is an important deformation mode in the thermal fatigue cycle. In this work, the creep behaviour of a solder joint is studied to determine the solder's microstructural response to this type of deformation and to relate this to the more complex problem of thermal fatigue. It is shown that creep failures arise from the inherent inhomogeneity and instability of the solder microstructure and suggest that small compositional changes of the binary near-eutectic Pn-Sn alloy may defeat the observed failure mechanisms. This work presents creep and thermal fatigue data for several near-eutectic Pb-Sn solder compositions and concludes that a 58Sn-40Pb-2In and a 58Sn-40Pb-2Cd alloy show significantly enhanced fatigue resistance over that of the simple binary material. 80 refs., 33 figs., 1 tab.

  6. Evaluation of Scattered Wave and Stress Concentration Field in a Damaged Solder Joint

    Science.gov (United States)

    Dineva, P.; Gross, D.; Rangelov, T.

    1999-06-01

    Two different, but equally important problems for solder joint reliability are solved. The evaluation of the dynamic stress concentration field in the thin base layer of a damaged solder joint is the first one. It is considered as a rectangular plate with a central macro-crack surrounded with randomly distributed micro-cracks, subjected to uniform time-harmonic tension. The damaged solder joint state is described by the model of Gross and Zhang [1] (International Journal of Solids and Structures29, 1763-1779). The information of the stress concentration field in a damaged solder joint is important to understand the mechanisms in the base components of all electronic packages.The second problem is ultrasonic wave scattering in a solder joint damaged by micro-cracks, considered as a two-dimensional finite multi-layered system. The solution of this problem may aid the creation of the modern non-destructive evaluation method (NDEM) for a high quality control of products in electronic industry.The method of the solution of both boundary-value problems is a direct BIEM (boundary integral equation method). The numerical results obtained for a solder joint with real geometry and physical properties show how the acoustic and stress concentration fields depend on the solder joint damage state. The character of this dependence is discussed.

  7. Diclofenac epolamine plus heparin plaster versus diclofenac epolamine plaster in mild to moderate ankle sprain: a randomized, double-blind, parallel-group, placebo-controlled, multicentre, phase III trial.

    Science.gov (United States)

    Costantino, Cosimo; Kwarecki, Jacek; Samokhin, Anatoly V; Mautone, Giuseppe; Rovati, Stefano

    2011-01-01

    In general sports, ankle sprain is the most frequently reported ankle injury and can cause chronic lateral ankle pain and tenderness. Treatment with NSAIDs is preferred, and several topical NSAID formulations are now available, helping to avoid the systemic adverse events typically associated with oral preparations. To compare the efficacy and tolerability of a newly developed fixed-dose diclofenac epolamine (diclofenac hydroxyethylpyrrolidine, DHEP)/heparin plaster (Flectoparin® Tissugel) with that of a DHEP (Flector EP Tissugel®) or placebo plaster in the treatment of mild to moderate ankle sprain in adults. This was a randomized, double-blind, parallel-group, placebo-controlled, multicentre, phase III study conducted in the emergency medical centres of hospitals or private clinics in Europe. Outpatients aged 18-65 years who had suffered an acute ankle sprain (O'Donoghue grade I or II in severity, with external lateral ligament involvement) within the previous 48 hours and had peri-malleolar oedema were eligible for inclusion. A total of 430 patients were randomized to receive a DHEP/heparin 1.3%/5600 IU (n = 142), DHEP 1.3% (n = 146) or placebo (n = 142) plaster, applied once daily to the injured ankle for a total of 7 days. The primary endpoint was the mean change from baseline in pain on movement on day 3, as measured by a visual analogue scale (VAS). The DHEP/heparin plaster was associated with a significantly (p = 0.002) greater mean reduction from baseline in pain on movement after 3 days of treatment than the DHEP plaster (-24.2 vs -18.8 mm VAS), with each active treatment providing significantly (p ≤ 0.005) greater pain relief than placebo (-13.7 mm VAS). Both DHEP/heparin and DHEP were also effective in relieving other measures of pain, with DHEP/heparin recipients experiencing significantly less daily pain while leaning on the injured limb than DHEP recipients (p plaster and DHEP plaster were both well tolerated, with

  8. Wettability Studies of Pb-Free Soldering Materials

    Science.gov (United States)

    Moser, Z.; Gąsior, W.; Pstruś, J.; Dębski, A.

    2008-12-01

    For Pb-free soldering materials, two main substitutes are currently being considered, consisting of Sn-Ag and Sn-Ag-Cu eutectics, both with melting points higher than that of the Sn-Pb eutectic. Therefore, both will require higher soldering temperatures for industrial applications. Also, both eutectics have a higher surface tension than the Sn-Pb eutectic, requiring wettability studies on adding Bi, Sb, and In to the eutectics to decrease the melting points and surface tension. The experimental results for the surface tension were compared with thermodynamic modeling by Butler’s method and were used to create the SURDAT database, which also includes densities for pure metals, binary, ternary, quaternary, and quinary alloys. To model the surface tension, excess Gibbs energies of the molten components were taken from the ADAMIS database. For the case of the Ag-Sn system, enthalpies of formation of Ag3Sn from solution calorimetry were used for checking optimized thermodynamic parameters. In the study of Sn-Ag-Cu-Bi-Sb liquid alloys, the range of possible Bi compositions for practical applications has been used to formulate a generalized metric of wettability, which was checked by measurements of the influence of In on the Sn-Ag-Cu system.

  9. Effect of contact metallization on electromigration reliability of Pb-free solder joints

    Science.gov (United States)

    Ding, Min; Wang, Guotao; Chao, Brook; Ho, Paul S.; Su, Peng; Uehling, Trent

    2006-05-01

    The effect of underbump metallization (UBM) on electromigration (EM) lifetime and failure mechanism has been investigated for Pb-free solder bumps of 97Sn3Ag composition in the temperature range of 110-155 °C. The EM lifetime of the SnAg Pb-free solders with either Cu or Ni UBM was found to be better than the eutectic SnPb (63Sn37Pb) solders but worse than high-Pb (95Pb5Sn) solders. In the test temperature range, the EM lifetimes were found to be comparable for Cu and Ni UBMs but with different activation energies: 0.64-0.72 eV for Cu UBM and 1.03-1.11 eV for Ni UBM. EM failure was observed only in solder bumps with electron current flow from UBM to the substrate. Failure analysis revealed that EM damage was initiated by the formation of intermetallic compounds (IMC) at the UBM/solder interface which was found to be significantly enhanced by mass transport driven by the electron current. Under EM, the continued growth of IMC with the dissolution of the UBM and the accumulation of Kirkendall voids resulted in the formation of interfacial cracks and eventual EM failure of the solder bump. For Ni UBM, the IMC formation was dominated by the Ni3Sn4 phase while for Cu UBM, a bilayer of Cu3Sn/Cu6Sn5 was found. Void formation at the Cu6Sn5/solder interface was found to be important in controlling the EM lifetime of the Cu UBM solder.

  10. 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.

  11. Research on Defects Inspection of Solder Balls Based on Eddy Current Pulsed Thermography

    Science.gov (United States)

    Zhou, Xiuyun; Zhou, Jinlong; Tian, Guiyun; Wang, Yizhe

    2015-01-01

    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. PMID:26473871

  12. Life Prediction of Ball Grid Array Soldered Joints under Thermal Cycling Loading by Fracture Mechanics Method

    Institute of Scientific and Technical Information of China (English)

    2001-01-01

    Fatigue crack propagation life of ball grid array (BGA) soldered joints during thermal cycling loading was investigated by fracture mechanics approach using finite element analysis. The relationships between the strain energy release rate (G) and crack size (α), thermal cycle numbers (N) can be derived. Based on the relationships, fatigue life of the soldered joints was determined. The results showed that crack propagation life was higher than crack initiation life. Therefore, it appears that it is more appropriate to predict the fatigue life of soldered joints using the fracture mechanics method.

  13. Research on defects inspection of solder balls based on eddy current pulsed thermography.

    Science.gov (United States)

    Zhou, Xiuyun; Zhou, Jinlong; Tian, Guiyun; Wang, Yizhe

    2015-10-13

    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.

  14. 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.

  15. Effect of constraint on crack propagation behavior in BGA soldered joints

    Institute of Scientific and Technical Information of China (English)

    王莉; 王国忠; 方洪渊; 钱乙余

    2001-01-01

    The effects of stress triaxiality on crack propagation behavior in the BGA soldered joint were analyzed using FEM method. The computation results verified that stress triaxiality factor has an important effect on crack growth behavior. Crack growth rate increased with increasing stress triaxiality at the near-tip region, which is caused by increasing crack lengths or decreasing solder joint heights. Solder joint deformation is subjected to constraint effect provided by its surrounding rigid ceramic substrate, the constraint can be scaled by stress triaxiality near crack tip region. Therefore, it can be concluded that crack growth rate increased when the constraint effect increases.

  16. Observations of microstructural coarsening in micro flip-chip solder joints

    Science.gov (United States)

    Barney, Monica M.; Morris, J. W.

    2001-09-01

    Coarsening of solder microstructures dramatically affects fatigue lifetimes. This paper presents a study of microstructural evolution due to thermal cycling and aging of small solder joints. The lead-tin solder joints in this study have a height of 55 5 m and a tin content of 65 70 wt.%, with a degenerate eutectic microstructure. The joint microstructure coarsens more rapidly during aging at 160°C than cycling from 0 160°C. No coarsened bands are observed. The cycling data scales with standard coarsening equations, while the aging data fits to an enhanced trend. The joints experiencing 2.8% strain during cycling fail by 1000 cycles.

  17. 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.

  18. A cause of the non-solderability of ceramic capacitor terminations

    Science.gov (United States)

    Cozzolino, M. J.; Kumar, A.; Ewell, G. J.

    1981-01-01

    The results of an analysis into the cause of the non-solderability of multiple defective part lots from two capacitor manufacturers are described. This analysis consisted of visual, scanning electron microscopic, surface, and metalographic examinations and analyses. The results indicated that non-solderability results from areas of excess porosity in the termination which are caused by segregation of ink constituents during manufacturing. This segregation can be minimized by proper monitoring and control of process variables; where excess porosity does occur, solderability can be improved by proper precleaning of parts.

  19. Wettability study of lead free solder paste and its effect towards multiple reflow

    OpenAIRE

    Idris Siti Rabiatull Aisha; Zuleikha Siti; Abd Malek Zetty Akhtar

    2016-01-01

    Nowadays, wafer bumping using solder paste has come into focus as it provides a low cost method. However, since the industries are moving towards lead-free electronic packaging, a new type of no-clean flux was produced specifically for lead-free solder paste. Therefore, this study is used to evaluate the wettability of two different types of no-clean flux onto copper substrate. Besides, its effect towards multiple reflow was also studied. Reflow soldering was conducted for both types of solde...

  20. Can treatment success with 5% lidocaine medicated plaster be predicted in cancer pain with neuropathic components or trigeminal neuropathic pain?

    Science.gov (United States)

    Kern, Kai-Uwe; Nalamachu, Srinivas; Brasseur, Louis; Zakrzewska, Joanna M

    2013-01-01

    An expert group of 40 pain specialists from 16 countries performed a first assessment of the value of predictors for treatment success with 5% lidocaine-medicated plaster in the management of cancer pain with neuropathic components and trigeminal neuropathic pain. Results were based on the retrospective analysis of 68 case reports (sent in by participants in the 4 weeks prior to the conference) and the practical experience of the experts. Lidocaine plaster treatment was mostly successful for surgery or chemotherapy-related cancer pain with neuropathic components. A dose reduction of systemic pain treatment was observed in at least 50% of all cancer pain patients using the plaster as adjunct treatment; the presence of allodynia, hyperalgesia or pain quality provided a potential but not definitively clear indication of treatment success. In trigeminal neuropathic pain, continuous pain, severe allodynia, hyperalgesia, or postherpetic neuralgia or trauma as the cause of orofacial neuropathic pain were perceived as potential predictors of treatment success with lidocaine plaster. In conclusion, these findings provide a first assessment of the likelihood of treatment benefits with 5% lidocaine-medicated plaster in the management of cancer pain with neuropathic components and trigeminal neuropathic pain and support conducting large, well-designed multicenter studies.

  1. Functional exercise in combination with auricular plaster therapy is more conducive to rehabilitation of menopausal women patients with anxiety disorder.

    Science.gov (United States)

    Han, Yubin; Duan, Fugui; Xu, Rongmei; Wang, Yi; Zhang, Hongyu

    2015-01-01

    Observe the effect of functional exercise in combination with auricular plaster therapy on menopausal women patients with anxiety disorder. Select 45 menopausal women patients with anxiety disorder and then adopt random digital table to divide them into a functional exercise group, an auricular plaster therapy group and a combination group. Each group consists of 15 patients. The patients in the functional exercise group do yoga exercise twice a day; those in the auricular plaster therapy group are provided with the auricular plaster therapy twice a day; those in the combination group do yoga exercise and then they are provided with the auricular plaster therapy twice a day. Before the treatment and after 12 weeks' treatment, respectively detect and compare the selected patients in the three groups in respect HAMA score, physical function score and mental function score; And the cured patients are followed up for 3 months to compare recurrence rate of each group. After 12 weeks' treatment, HAMA score, physical function score and mental function score of the combination group are obviously better than those of another two groups (Pplaster, the combined curative effect is obviously better than that of single treatment and the clinical recurrence rate is significantly lower than that of single treatment. It shows that the combined treatment method presents obvious synergistic effect and the synergistic treatment is more beneficial to improve the curative effect.

  2. Flexible intramedullary nails with traction versus plaster cast for treating femoral shaft fractures in children: comparative retrospective study.

    Science.gov (United States)

    Nascimento, Fabiano Prata do; Santili, Cláudio; Akkari, Miguel; Waisberg, Gilberto; Braga, Susana dos Reis; Fucs, Patrícia Maria Moraes de Barros

    2013-01-01

    CONTEXT AND OBJECTIVE Femoral fractures are common in children between 2 and 12 years of age, and 75% of the lesions affect the femoral shaft. Traction followed by a plaster cast is universally accepted as conservative treatment. However, in some situations, a surgical approach is recommended. The objective here was to compare treatments for femoral shaft fractures using intramedullary nails (titanium elastic nails, TEN) versus traction and plaster casts in children. The hypothesis was that TEN might provide better treatment, with good clinical results in comparison with plaster casts. DESIGN AND SETTING This retrospective comparative study was conducted in a public university hospital. METHODS Sixty children with femoral fractures were evaluated; 30 of them underwent surgical treatment with TEN and 30 were treated conservatively using plaster casts. The patients' ages ranged from 5 to 13 years (mean of 9 years). RESULTS The mean duration of hospitalization was nine days for the surgical group and 20 days for the conservative group. The incidence of overgrowth in the patients treated with TEN was 60.0% and, for those treated conservatively, 13.3%. Partial weight-bearing was allowed after 3.5 weeks in the surgical group and after 9.6 weeks in the conservative group. New hospitalization was required for 90.0% in the surgical group and 16.7% in the conservative group. Patients treated with plaster casts presented higher incidence of complications, such as loss of reduction. CONCLUSIONS The surgical method presented better results for children.

  3. 5% Lidocaine Medicated Plaster for the Treatment of Postherpetic Neuralgia: A Review of the Clinical Safety and Tolerability.

    Science.gov (United States)

    Navez, Marie Louise; Monella, Christopher; Bösl, Irmgard; Sommer, Daniela; Delorme, Claire

    2015-06-01

    Postherpetic neuralgia (PHN) is a common, very painful, and often long-lasting complication of herpes zoster which is frequently underdiagnosed and undertreated. It mainly affects the elderly, many of whom are already treated for comorbidities with a variety of systemic medications and are thus at high risk of drug-drug interactions. An efficacious and safe treatment with a low interaction potential is therefore of high importance. This review focuses on the safety and tolerability of the 5% lidocaine medicated plaster, a topical analgesic indicated for the treatment of PHN. The available literature (up to June 2014) was searched for publications containing safety data regarding the use of the 5% lidocaine medicated plaster in PHN treatment; unpublished clinical safety data were also included in this review. The 5% lidocaine medicated plaster demonstrated good short- and long-term tolerability with low systemic uptake (3 ± 2%) and minimal risk for systemic adverse drug reactions (ADRs). ADRs related to topical lidocaine treatment were mainly application site reactions of mild to moderate intensity. The treatment discontinuation rate was generally below 5% of patients. In one trial, the 5% lidocaine medicated plaster was better tolerated than systemic treatment with pregabalin. The 5% lidocaine medicated plaster provides a safe alternative to systemic medications for PHN treatment, including long-term pain treatment.

  4. Can treatment success with 5% lidocaine medicated plaster be predicted in cancer pain with neuropathic components or trigeminal neuropathic pain?

    Science.gov (United States)

    Kern, Kai-Uwe; Nalamachu, Srinivas; Brasseur, Louis; Zakrzewska, Joanna M

    2013-01-01

    An expert group of 40 pain specialists from 16 countries performed a first assessment of the value of predictors for treatment success with 5% lidocaine-medicated plaster in the management of cancer pain with neuropathic components and trigeminal neuropathic pain. Results were based on the retrospective analysis of 68 case reports (sent in by participants in the 4 weeks prior to the conference) and the practical experience of the experts. Lidocaine plaster treatment was mostly successful for surgery or chemotherapy-related cancer pain with neuropathic components. A dose reduction of systemic pain treatment was observed in at least 50% of all cancer pain patients using the plaster as adjunct treatment; the presence of allodynia, hyperalgesia or pain quality provided a potential but not definitively clear indication of treatment success. In trigeminal neuropathic pain, continuous pain, severe allodynia, hyperalgesia, or postherpetic neuralgia or trauma as the cause of orofacial neuropathic pain were perceived as potential predictors of treatment success with lidocaine plaster. In conclusion, these findings provide a first assessment of the likelihood of treatment benefits with 5% lidocaine-medicated plaster in the management of cancer pain with neuropathic components and trigeminal neuropathic pain and support conducting large, well-designed multicenter studies. PMID:23630431

  5. Effect of Surface Finish of Substrate on Mechanical Reliability of in-48SN Solder Joints in Moems Package

    CERN Document Server

    Koo, Ja-Myeong

    2007-01-01

    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 (hereafter OSP). During bonding, continuous AuIn2, Ni3(Sn,In)4 and Cu6(Sn,In)5 intermetallic compound (IMC) layers were formed at the solder/E-NG, solder/ENIG and solder/OSP interface, respectively. The interfacial reactions between the solder and I-Ag substrate during bonding resulted in the formation of Cu6(Sn,In)5 and Cu(Sn,In)2 IMCs with a minor Ag element. The In-48Sn/I-Ag solder joint showed the best shear properties among the four solder joints after bonding, whereas the solder/ENIG solder joint exhibited the weakest mechanical integrity.

  6. Electromigration Reliability and Morphologies of Cu Pillar Flip-Chip Solder Joints with Cu Substrate Pad Metallization

    Science.gov (United States)

    Lai, Yi-Shao; Chiu, Ying-Ta; Chen, Jiunn

    2008-10-01

    The Cu pillar is a thick underbump metallurgy (UBM) structure developed to alleviate current crowding in a flip-chip solder joint under operating conditions. We present in this work an examination of the electromigration reliability and morphologies of Cu pillar flip-chip solder joints formed by joining Ti/Cu/Ni UBM with largely elongated ˜62 μm Cu onto Cu substrate pad metallization using the Sn-3Ag-0.5Cu solder alloy. Three test conditions that controlled average current densities in solder joints and ambient temperatures were considered: 10 kA/cm2 at 150°C, 10 kA/cm2 at 160°C, and 15 kA/cm2 at 125°C. Electromigration reliability of this particular solder joint turns out to be greatly enhanced compared to a conventional solder joint with a thin-film-stack UBM. Cross-sectional examinations of solder joints upon failure indicate that cracks formed in (Cu,Ni)6Sn5 or Cu6Sn5 intermetallic compounds (IMCs) near the cathode side of the solder joint. Moreover, the ~52- μm-thick Sn-Ag-Cu solder after long-term current stressing has turned into a combination of ~80% Cu-Ni-Sn IMC and ~20% Sn-rich phases, which appeared in the form of large aggregates that in general were distributed on the cathode side of the solder joint.

  7. Study of plaster finishes on San Pedro de los Francos church at Calatayud

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    Sánchez de Rojas, Mª I

    2007-06-01

    Full Text Available This study of the plaster finishes on San Pedro de los Francos Church at Calatayud revealed, firstly, the stratigraphic sequence based on the interpretation of the bonding interfaces; and secondly, the evolution of placement techniques from mudéjar style textured and painted false stonework (15th century to the smooth plastering and paint typical of later phases. Finally, scanning electron microscope (SEM, energy dispersive X-ray microanalysis (EDX and X-ray diffraction (XRD studies showed that gypsum and anhydrite are the main components of both binder and aggregate in these mortars. In other words, they constitute traditional multiphase plasters whose coarser particles or aggregate were a byproduct of the artisanal manufacturing process.El estudio de los enlucidos de la iglesia de San Pedro de los Francos de Calatayud ha permitido demostrar, en primer lugar, la secuencia estratigráfica mediante la lectura de la interfase de adherencia; en segundo lugar, la evolución de las técnicas de aplicación, desde el enlucido mudéjar, un fingido de piedra agramilado y pintado (siglo XV, hasta los enlucidos lisos y pinturas aplicados posteriormente. Y, finalmente, a través de los estudios de microscopía electrónica de barrido (SEM, microanálisis por energía dispersiva de rayos X (EDX y de difracción de rayos X (DRX, se ha determinado que son morteros en los que tanto el conglomerante como el árido son yeso y anhidrita, que correspondería a un yeso tradicional multifase, cuyos granos más gruesos analizados como áridos proceden del producto obtenido artesanalmente.

  8. 5% lidocaine medicated plaster double effect in a case of orofacial localized neuropathic pain

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    Casale R

    2014-11-01

    Full Text Available Roberto Casale,1,2 Yuriy Romanenko,2,3 Massimo Allegri4–6 1Department of Clinical Neurophysiology and Pain Rehabilitation Unit, Foundation "Salvatore Maugeri", Research and Care Institute, IRCCS, Pavia, Italy; 2EFIC Montescano Pain School, Montescano, Italy; 3Department of Neurology, Lugansk City Hospital 4, Lugansk, Ukraine; 4Department of Clinical, Surgical, Diagnostic and Pediatric Sciences University of Pavia, Pavia, Italy; 5Pain Therapy Service Fondazione IRCCS Policlinico San Matteo, Pavia, Italy; 6SIMPAR group, Pavia, Italy Abstract: Localized neuropathic pain (LNP is a type of neuropathic pain that is characterized by “consistent and limited area(s of maximum pain associated with negative or positive sensory signs and/or spontaneous symptoms characteristic of neuropathic pain”. This definition encompasses a huge number of neuropathic orofacial pain syndromes. We present a case report of a patient who was affected with sleep apnea syndrome treated with nocturnal oxygen mask delivery, in whom orofacial LNP hampered the wearing of a mask due to unbearable burning and throbbing pain. The application of 5% lidocaine medicated plaster during the night led to an impressive reduction of both the pain level and the size of the painful area due to the plaster's pharmacological mechanisms, which were associated with a secondary benefit due to its mechanical protective action. This case report shows how these two factors could be of clinical value and have to be considered more systematically in the treatment of LNP in reducing pain and the size of the painful area. Keywords: trigeminal pain, localized neuropathic pain, topical treatment, 5% lidocaine medicated plaster

  9. [Efficacy on borderline hypertension treated with acupuncture combined with anti-hypertensive plaster intervention].

    Science.gov (United States)

    Li, Yan-mei

    2014-11-01

    To compare the efficacy difference in treatment of borderline hypertension between acupuncture combined with anti-hypertensive plaster and simple acupuncture. Sixty patients of borderline hypertension were randomized into an observation group and a control group, 30 cases in each one. In the observation group, acupuncture was applied to Fengchi (GB 20), Taichong (LR 3) and the others, once a day, 5 treatments made one session. There were 2 days at interval among the sessions. Totally, 4 sessions were required. Additionally, in combination, the anti-hypertensive plaster was prepared with the fine powder of Chuanxiong (ligusticum wallichii) and Wuzhuyu (fructus evodiae) at 1.1 and mixed with vinegar. The plaster was applied to the umbilicus, once every two days, totally 15 times were required. In the control group, acupuncture was given simply. The selected acupoints and operation were the same as the observation group. Before and after treatment, blood pressure and syndrome score were observed and the short-term and long-term efficacies were assessed in the two groups. After treatment, the systolic pressure and diastolic pressure were reduced as compared with those before treatment in the two groups (all P0.05). In follow-up of the effective cases and remarkably effective cases in 3 months, the total effective rate in the observation group was 89.3% (25/28) and was 60.0% (15/25) in the control group, indicating the significant difference in comparison (Pplaster is the effective method in prevention and treatment of borderline hypertension. Regarding the long-term efficacy, this combined therapy achieves the superior improvement in the symptoms and physical signs of the patients of borderline hypertension as compared with simple acupuncture.

  10. Comparative study of dental arch width in plaster models, photocopies and digitized images

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    Maria Cristina Rosseto

    2009-06-01

    Full Text Available The aim of this study was to comparatively assess dental arch width, in the canine and molar regions, by means of direct measurements from plaster models, photocopies and digitized images of the models. The sample consisted of 130 pairs of plaster models, photocopies and digitized images of the models of white patients (n = 65, both genders, with Class I and Class II Division 1 malocclusions, treated by standard Edgewise mechanics and extraction of the four first premolars. Maxillary and mandibular intercanine and intermolar widths were measured by a calibrated examiner, prior to and after orthodontic treatment, using the three modes of reproduction of the dental arches. Dispersion of the data relative to pre- and posttreatment intra-arch linear measurements (mm was represented as box plots. The three measuring methods were compared by one-way ANOVA for repeated measurements (α = 0.05. Initial / final mean values varied as follows: 33.94 to 34.29 mm / 34.49 to 34.66 mm (maxillary intercanine width; 26.23 to 26.26 mm / 26.77 to 26.84 mm (mandibular intercanine width; 49.55 to 49.66 mm / 47.28 to 47.45 mm (maxillary intermolar width and 43.28 to 43.41 mm / 40.29 to 40.46 mm (mandibular intermolar width. There were no statistically significant differences between mean dental arch widths estimated by the three studied methods, prior to and after orthodontic treatment. It may be concluded that photocopies and digitized images of the plaster models provided reliable reproductions of the dental arches for obtaining transversal intra-arch measurements.

  11. A new portable vibrator for plaster pouring: effect on the marginal fit at cylinder-abutment

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    Pâmela Cândida Aires Ribas de Andrade

    2012-10-01

    Full Text Available OBJECTIVE: The aim of this study was to test a new portable vibrator for plaster pouring (developed for this purpose, comparing the effect of its use on the accuracy of working cast of implant-supported restorations to the conventional vibrator. MATERIAL AND METHODS: From a master cast with 2 implants, 30 transfer moldings were made randomly and divided into three groups: Group I (GI: pouring performed in an outsourced dental laboratory with conventional plaster vibrator (10 casts, Group II (GII: pouring performed in the laboratory of the Federal University of Santa Catarina (UFSC with conventional plaster vibrator (10 casts and Group III (GIII: pouring performed with the portable vibrator fabricated for this study (10 casts. The position of the analogue and marginal adaptation of the infrastructure were verified by testing the single screw on the master model and on the working model. The measurement of misfit was blindly performed with a precision microscope and analyzing unit, Quadra-Check 200. The data were statistically analyzed by analysis of variance (ANOVA and the Holm-Sidak test (α=0.05. RESULTS: Means±standard deviations were as follows: GI: 19.19±4.73 µm; GII: 21.72±5.41 µm; GIII: 13.5±2.39 µm (P<0.05, with GIII significantly lower as compared to the other groups. CONCLUSION: Within the limitations of this study, it was concluded that a greater accuracy of working cast was achieved when a portable vibrator was used for casting molds.

  12. Properties of type IV plaster considering variation in the mold/model position during setting stage

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    Tarcisio José de Arruda Paes Junior

    2010-04-01

    Full Text Available Objective: To assess the influence of the position of the mold during the setting stage of type IV stone plaster Durone (Dentsply Ind. Com., Rio de Janeiro, Brazil, on the following properties: surface hardness and roughness. Methods: For the roughness test, two groups (n=6 in the form of pellets were prepared. In the first group, the surface of the base of the device was turned down during the plaster setting stage (N, in the second group this position was inverted, which has been described as an act of capsize it (E. For analysis, a roughness meter with reading precision of 0.01 μm was used. With regard to the hardness analysis, two groups with conical-shaped samples were obtained. The plasters were left to set under the same conditions of the mold/model position described for the previous experiment. Hardness measurement was performed in a durometer with a spherical penetrating tip for Rockwell readout. Three measurements were performed for each test specimen in both tests. Results: The hardness (N - 39.8, standard deviation = 3.3, E - 30.8, standard deviation = 5.6 and roughness data (N - 0.67, standard deviation = 0.17, E - 0.74, standard deviation = 0.13 submitted to the Student’s-t test (5% showed no statistically significant differences for the roughness test (0.489, but showed statistically significant differences for the hardness test (0.014. Conclusion: The variation in the mold/model position influenced the final characteristics of the specimens in terms of hardness, since those obtained with the capsize technique showed lower surface hardness, whereas for roughness these differences were not statistically significant.

  13. Dispersebility degree influence of glass fibre E in the mechanical behaviour and workability of plaster

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    del Río Merino, M.

    2001-03-01

    Full Text Available Although there are many research studies about plaster strengthened with glass fibre E in Spain, there are no publications which advise the users (plasterers, manufacturers of prefabricated blocks or suspended ceilings, etc about the most appropriated types of fibre E in respect to its dispersebility degree in the matrix, its lengths, the percentage, or even the type of strengthening, etc. The study of the use of this strengthener is to achieve an improvement in the mechanical behaviour of plaster as well as better conditions in the paste workability. The company Vetrotex, with the technical personnel and together with the Department of Architectural Constructions and their control (E. U. A. T. M. have started a serious research on plaster strengthened with E fibre. Conclusions shown in this first article are about the influence of the dispersebility degree of glass fibres in the mechanical behaviour of the compound as well as its workability. The degree of dispersibility of the fibres in the matrix is closely related to the type of covering used in the production of the strengthening fibres.

    Aunque existen muchos trabajos de investigación sobre el refuerzo del yeso con fibra de vidrio E en España, no hay publicaciones que asesoren a los usuarios (aplicadores de yeso proyectado, fabricantes de prefabricados como bloques o falsos techos, etc. de los tipos défibra de vidrio E más adecuados, atendiendo a su grado de dispersabilidad en la matriz, las longitudes, el porcentaje, e incluso el tipo de refuerzo, etc., a efectos de conseguir un aumento del comportamiento mecánico del yeso/escayola y unas ciertas condiciones de trabajabilidad de la pasta. La empresa Vetrotex, a través de sus técnicos y en colaboración con el Departamento de Construcciones Arquitectónicas y su control (E. U. A. T. M., decide acometer un estudio en profundidad de la escayola reforzada con fibra de vidrio E. En este primer artículo se presentan las

  14. Internal plate fixation versus plaster in displaced complete articular distal radius fractures, a randomised controlled trial.

    Science.gov (United States)

    Mulders, Marjolein A M; Walenkamp, Monique M J; Goslings, J Carel; Schep, Niels W L

    2016-02-09

    Of all distal radius fractures, 25 % are complete articular fractures (AO/OTA type C fractures). Two thirds of those fractures are displaced and require reduction. According to several International Guidelines, adequately reduced intra-articular distal radius fractures are best treated non-operatively with plaster immobilisation, while surgical fixation is suggested only when the articular step exceeds 2 mm after reduction. However, these recommendations are based on studies that did not differentiate between intra- and extra-articular distal radius fractures. Thus, no clear consensus about the best treatment for patients with displaced intra-articular distal radius fractures can be reached. Despite the lack of evidence, an increase in internal fixation of intra-articular distal radius fractures has been observed over the last decade. The aim of this study is to determine the difference in functional outcome following open reduction and plate fixation compared with non-operative treatment with closed reduction and plaster immobilisation in patients with a displaced intra articular distal radius fracture. This multicentre randomised controlled trial will randomise between open reduction and internal plate fixation (intervention group) and closed reduction and plaster immobilisation (control group). All consecutive adult patients from 18 to 65 years with a displaced intra-articular distal radius fracture (AO/OTA type C), which has been adequately reduced at the Emergency Department according to the Dutch National Guidelines, are eligible for inclusion in this study. The primary outcome is function and pain of the wrist assessed with the Patient-Rated Wrist Evaluation score (PRWE). Secondary outcomes are the Disability of the Arm, Shoulder and Hand score (DASH), pain, quality of life (SF-36), range of motion, grip strength, radiological parameters, complications, crossovers and cost-effectiveness of both treatments. A total of 90 patients will be included in this

  15. Effects of Plaster of Paris waste on the mechanical properties of pottery

    Science.gov (United States)

    Badarulzaman, N. A.; Nawi, A. M.; Ibrahim, M.

    2015-05-01

    Ceramic waste may come from ceramics industry such as Plaster of Paris(POP) mould waste. The purpose of this study is to investigate the possibility of using POP as filler in the manufacturing of pottery. The different weight percentage of filler (0 wt.%, 2 wt.%,4 wt.%, 6wt.%, 8wt.%) content were added into the composition of pottery. The samples were characterized via viscosity test and bending test. The result of the study revealed that the weight percent of waste POP increase affects the physical properties with increasing the strength values.

  16. Computer aided process of dimensional distortion determination of bounded plaster sandmix Part II

    OpenAIRE

    Pawlak, M.; Z. Niedźwiedzki

    2010-01-01

    A computer program allowing calculation of dimensional changes of mould made of cristobalite-gypsum composition in process of its heat treatment and preparation for molten metal casting is presented in this paper. The composition of the mixture and casting temperature to obtain cast of predetermined dimensions can be calculated using presented software. The base for program elaboration were the results of dilatometric test of bounded plaster sandmix composed of half hydrate α-CaSO4·0,5H2O of ...

  17. Computer aided process of dimensional distortion determination of bounded plaster sandmix Part II

    Directory of Open Access Journals (Sweden)

    M. Pawlak

    2010-01-01

    Full Text Available A computer program allowing calculation of dimensional changes of mould made of cristobalite-gypsum composition in process of its heat treatment and preparation for molten metal casting is presented in this paper. The composition of the mixture and casting temperature to obtain cast of predetermined dimensions can be calculated using presented software. The base for program elaboration were the results of dilatometric test of bounded plaster sandmix composed of half hydrate α-CaSO4·0,5H2O of various cristobalite ratio. Approximation was carried out in the range of temperatures 100÷700°C.

  18. 5% lidocaine medicated plaster in elderly patients with postherpetic neuralgia: results of a compassionate use programme in France.

    Science.gov (United States)

    Clère, Florentin; Delorme-Morin, Claire; George, Brigitte; Navez, Malou; Rioult, Bruno; Tiberghien-Chatelain, Florence; Ganry, Hervé

    2011-09-01

    Postherpetic neuralgia (PHN) is a common, debilitating complication of herpes zoster that has a major impact on patients' quality of life. PHN prevalence increases with advancing age. One treatment option is the topical analgesic 5% lidocaine (lignocaine) medicated plaster (Versatis®), which has been proven to be efficacious and well tolerated in a number of randomized clinical studies. The aim of this analysis was to assess the use of the lidocaine medicated plaster under clinical practice conditions in a patient population whose previous PHN treatment with antidepressant and/or antiepileptic agents was inadequate or was not tolerated, or for whom such treatment was contraindicated or not recommended. This was a prospective, multicentre, non-interventional observation conducted in private and public health centres in France under a compassionate use programme (CUP). To obtain this new - and, at the time, unauthorized - PHN treatment alternative, physicians (in accordance with French guidelines) had to complete standardized case report forms for each patient before his/her inclusion in the CUP. As it was a CUP and therefore a non-interventional observation, returning documented information on follow-up visits to the medication provider was voluntary, and only a limited number of physicians returned completed forms. Documentation was, however, mandatory for adverse events (AEs) occurrence. Depending on the size of the painful skin area, up to three lidocaine plasters daily were applied for a maximum of 12 hours with plaster-free intervals of at least 12 hours. The study assessed changes in the prescription of concomitant PHN medication from the start of lidocaine plaster treatment to the last follow-up visit, both in terms of the sum of all concomitant PHN treatments and stratified by type of treatment: antiepileptic drugs, tricyclic antidepressants (TCAs), serotonin reuptake inhibitors (SRIs), classical analgesics (classified as step 1, 2 or 3 according to the WHO

  19. Gray level co-occurrence and random forest algorithm-based gender determination with maxillary tooth plaster images.

    Science.gov (United States)

    Akkoç, Betül; Arslan, Ahmet; Kök, Hatice

    2016-06-01

    Gender is one of the intrinsic properties of identity, with performance enhancement reducing the cluster when a search is performed. Teeth have durable and resistant structure, and as such are important sources of identification in disasters (accident, fire, etc.). In this study, gender determination is accomplished by maxillary tooth plaster models of 40 people (20 males and 20 females). The images of tooth plaster models are taken with a lighting mechanism set-up. A gray level co-occurrence matrix of the image with segmentation is formed and classified via a Random Forest (RF) algorithm by extracting pertinent features of the matrix. Automatic gender determination has a 90% success rate, with an applicable system to determine gender from maxillary tooth plaster images. Copyright © 2016 Elsevier Ltd. All rights reserved.

  20. Treatment of postherpetic neuralgia with 5% lidocaine medicated plaster in elderly patients - subgroup analyses from three European clinical trials.

    Science.gov (United States)

    Sabatowski, Rainer; Bösl, Irmgard; König, Simone; Buchheister, Bettina; Meier, Torsten; Baron, Ralf

    2017-03-01

    To investigate short- and long-term effectiveness and safety of the 5% lidocaine medicated plaster in the treatment of postherpetic neuralgia (PHN) in elderly patients (≥70 years of age). Data from three European clinical trials was compared after stratification according to age (85% of elderly, >78% of younger patients) which was described by >51% as painful or extremely painful. Allodynia severity was markedly reduced in both groups during all three trials. Drug-related adverse events occurred in plaster provided pain relief and marked reductions in allodynia severity in elderly PHN patients with an excellent safety profile under short- and long-term treatment supporting the addition of the plaster to the treatment armamentarium for this age group. All analyzed study phases were open-label and lacking a placebo control group.

  1. [Implementing ambulatory prevention of thrombosis with low molecular weight heparin in plaster immobilization of the lower extremity].

    Science.gov (United States)

    Kock, H J; Schmit-Neuerburg, K P; Hanke, J; Terwort, A; Rudofsky, G; Hirche, H

    1994-12-01

    Plaster cast immobilisation following trauma is a major risk factor for the development of deep vein thrombosis. In our controlled, randomized and prospective study in patients with minor injuries the incidence of deep vein thrombosis was 4.3% in conservatively treated outpatients with plaster cast immobilisation of the leg (n = 163 control group without prophylaxis). By application of low molecular weight heparin once daily the number of deep vein thrombosis in the prophylaxis group (n = 176) was reduced to 0% (p = 0.006). No severe side effects of low molecular weight heparin were observed. Subcutaneous injections were self-applicated by 89% of males and 72% of females. We conclude that thromboprophylaxis with low molecular weight heparin once daily is effective to reduce the risk of deep vein thrombosis in outpatients with plaster cast immobilisation of the leg.

  2. The Terapeutic Effects of Electrical Acupuncture and Auricular-Plaster in 32 Cases of Chronic Fatigue Syndrome

    Institute of Scientific and Technical Information of China (English)

    Li Yuemei; Liu Hongping; Feng Shulan; Gong Dongfang

    2006-01-01

    Objective:To observe the therapeutic effects of electrical acupuncture and auricular-plaster therapy for chronic fatigue syndrome(CFS).Method:64 CFS patients were randomly divided into two groups.32 cases in the treatment group were treated by the electrical acupuncture and auricular-plaster therapy,and 32 cases in the control group with oral hydrocortisone.Results:The total effective rates were respectively 93.75% in the treatment group and 75.00% in the control group,with a statistically significant difference between the two groups(P<0.05).Conclusion:Electrical acupuncture and auricular-plaster therapy may show a better anti-fatigue effect than that of routine Western drugs.

  3. Abnormal growth of Ag3Sn intermetallic compounds in Sn-Ag lead-free solder

    Institute of Scientific and Technical Information of China (English)

    SHEN Jun; LIU Yongchang; GAO Houxiu

    2006-01-01

    The abnormal growth of Ag3Sn intermetallic compounds in eutectic Sn-3.5% Ag solder was investigated through high-temperature aging treatment. Microstructural evolutions of this solder before and after the aging treatment were observed by optical microscopy and scanning electron microscopy. Precise differential thermal analysis was made to study the changes in enthalpies of the solder under different conditions. The results reveal that the water-cooled solder is in metastable thermodynamic state due to the high free energy of Ag3Sn nanoparticles, which sporadically distribute in the matrix as second-phase. The second-phase Ag3Sn nanoparticles aggregate rapidly and grow to form bulk intermetallic compounds due to the migration of grain boundary between primary Sn-rich phase and the Ag3Sn nanoparticles during high temperature aging treatment.

  4. 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

    Soldering of cast alloys to the dies has been a continuing source of die surface damage in the aluminum die-casting industry. To reduce the repair and maintenance costs, an approach to modeling the damage and predicting the die lifetime is required. The aim of the present study is the estimation...... 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...

  5. Climate specific thermomechanical fatigue of flat plate photovoltaic module solder joints

    Energy Technology Data Exchange (ETDEWEB)

    Bosco, Nick; Silverman, Timothy J.; Kurtz, Sarah

    2016-07-01

    FEM simulations of PbSn solder fatigue damage are used to evaluate seven cities that represent a variety of climatic zones. It is shown that the rate of solder fatigue damage is not ranked with the cities' climate designations. For an accurate ranking, the mean maximum daily temperature, daily temperature change and a characteristic of clouding events are all required. A physics-based empirical equation is presented that accurately calculates solder fatigue damage according to these three factors. An FEM comparison of solder damage accumulated through service and thermal cycling demonstrates the number of cycles required for an equivalent exposure. For an equivalent 25-year exposure, the number of thermal cycles (-40 degrees C to 85 degrees C) required ranged from roughly 100 to 630 for the cities examined. It is demonstrated that increasing the maximum cycle temperature may significantly reduce the number of thermal cycles required for an equivalent exposure.

  6. Thermal analysis of selected tin-based lead-free solder alloys

    DEFF Research Database (Denmark)

    Palcut, Marián; Sopoušek, J.; Trnková, L.

    2009-01-01

    The Sn-Ag-Cu alloys have favourable solderability and wetting properties and are, therefore, being considered as potential lead-free solder materials. In the present study, tin-based Sn-Ag-Cu and Sn-Ag-Cu-Bi alloys were studied in detail by a differential scanning calorimetry (DSC) and thermodyna......The Sn-Ag-Cu alloys have favourable solderability and wetting properties and are, therefore, being considered as potential lead-free solder materials. In the present study, tin-based Sn-Ag-Cu and Sn-Ag-Cu-Bi alloys were studied in detail by a differential scanning calorimetry (DSC...... was simulated using the Thermo-Calc software package. This approach enabled us to obtain the enthalpy of cooling for each alloy and to compare its temperature derivative with the experimental DSC curves....

  7. Shear Deformation Behaviors of Sn3.5Ag Lead-free Solder Samples

    Institute of Scientific and Technical Information of China (English)

    Jing Han; Hongtao Chen; Mingyu Li; Chunqing Wang

    2013-01-01

    In this study,shear tests have been performed on the as-reflowed Sn3.5Ag solder bumps and joints to investigate the deformation behavior of Sn3.5Ag lead-free solder samples.Scanning electron microscopy (SEM) was employed to characterize the microstructures of the samples and orientation imaging microscopy (OIM) with electron backscattered diffraction (EBSD) in SEM was used to obtain crystallographic orientation of grains to provide a detailed characterization of the deformation behavior in Sn3.5Ag solder samples after shear tests.The deformation behavior in solder samples under shear stress was discussed.The experimental results suggest that the dynamic recrystallization could occur under shear stress at room temperature and recrystallized grains should evolve from subgrains by rotation.Compared with that of non-recrystallized and as-reflowed microstructures,the microhardness of the recrystallized microstructure decreased after shear tests.

  8. Joint Strength with Soldering of Al2O3 Ceramics After Ni-P Chemical Plating

    Institute of Scientific and Technical Information of China (English)

    邹贵生; 吴爱萍; 张德库; 孟繁明; 白海林; 张永清; 黎义; 巫世杰; 顾兆旃

    2004-01-01

    Ni-P alloy was chemically plated on Al2O3 ceramics to produce uniform alloy coatings at temperatures below 70℃. Cu metal was electroplated onto the Ni-P coating to facilitate the soldering and shorten the chemical plating time. Then, the electroplated ceramic specimens were soldered with 60 wt.% Sn-40 wt.% Pb solder in active colophony. The highest shear strength was acquired after the heat treatment at 170℃ for 15 min. The joint fractures mostly propagated along the interface between the ceramics and the Ni-P coating, with some fracture in both the ceramics and the Ni-P coating near the interface and some along the interface between the Cu and Ni-P coatings. The results show that ceramic surface roughness and the chemical plating parameters influence the coating quality, and that suitable heat treatment before the soldering also improves the adhesion between the ceramics and Ni-P coatings, thus strengthening the joints.

  9. Correlation Between Sn Grain Orientation and Corrosion in Sn-Ag-Cu Solder Interconnects

    Science.gov (United States)

    Lee, Tae-Kyu; Liu, Bo; Zhou, Bite; Bieler, Thomas; Liu, Kuo-Chuan

    2011-09-01

    The impact of a marine environment on Sn-Ag-Cu interconnect reliability is examined using salt spray exposure followed by thermal cycling. Sn-Ag-Cu solder alloy wafer-level packages, with and without pretreatment with 5% NaCl salt spray, were thermally cycled to failure. The prior salt spray reduced the characteristic lifetime of the Sn-Ag-Cu solder joints by over 43%. Although Sn-based materials show strong resistance to corrosion, the nature of localized corroded areas at critical locations in the solder joint caused significant degradation in the Sn-Ag-Cu solder joints. An important link between the corrosion path and Sn grain orientation was observed using orientation imaging microscopy (OIM). A strong correlation between the corrosion path and grain orientation was identified, indicating that the corrosion attack preferentially followed the basal plane of the Sn lattice.

  10. Influence of Asymmetrical Waveform on Low-Cycle Fatigue Life of Micro Solder Joint

    Science.gov (United States)

    Kanda, Yoshihiko; Kariya, Yoshiharu

    2010-02-01

    The effects of waveform symmetry on the low-cycle fatigue life of the Sn-3.0Ag-0.5Cu alloy have been investigated, using micro solder joint specimens with approximately the same volume of solder as is used in actual products. Focusing on crack initiation life, fatigue tests on Sn-Ag-Cu micro solder joints using asymmetrical triangular waveforms revealed no significant reduction in fatigue life. A slight reduction in fatigue life at low strain ranges caused by an increase in the fatigue ductility exponent, which is the result of a weakening microstructure due to loads applied at high temperature for long testing time, was observed. This was due to the fact that grain boundary damage, which has been reported in large-size specimens subjected to asymmetrical triangular waveforms, does not occur in Sn-Ag-Cu micro size solder joints with only a small number of crystal grain boundaries.

  11. 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.

  12. Evaluation of Detachable Ga-Based Solder Contacts for Thermoelectric Materials

    Science.gov (United States)

    Kolb, H.; Sottong, R.; Dasgupta, T.; Mueller, E.; de Boor, J.

    2017-08-01

    Low electrical and thermal contact resistances are a prerequisite for highly efficient thermoelectric generators. Likewise, certain measurement setups for characterization of thermoelectric materials rely on good-quality contacts between sample and setup. Detachable contacts are an interesting alternative to permanent contacting solutions due to ease of handling and nondestructive disassembly of valuable samples. Therefore, the applicability of gallium-based liquid metal solder as detachable contact material was studied, particularly with regard to compatibility of the solder with state-of-the-art thermoelectric materials CoSb3, Mg2Si, and FeSi2. Tungsten, nickel, chromium, and titanium were tested as protective coatings between the thermoelectric material and liquid metal solder. Electrical measurements showed that some materials form excellent and stable contacts with the solder for a limited temperature range. At higher temperatures, application of a protective layer was found to be necessary for all investigated materials. Tungsten and nickel showed promising results as protective layer.

  13. Nano ZrO2 Particulate-reinforced Lead-Free Solder Composite

    Institute of Scientific and Technical Information of China (English)

    Jun SHEN; Yongchang LIU; Dongjiang WANG; Houxiu GAO

    2006-01-01

    A lead-free solder composite was prepared by adding ZrO2 nanopowders in eutectic Sn-Ag alloy. Microstructural features and microhardness properties of those solders with different ZrO2 nanopowder fraction were examined. Results indicate that the addition of ZrO2 nanopowders reduced the size ofβ-Sn grains and restrained the formation of bulk Ag3Sn intermetallic compounds (IMCs) due to the adsorption effect of the ZrO2 particles. The Vicker's hardness of the obtained lead-free solder composites fits well with the Hall-Petch relationship. The refinement of β-Sn grains favors to improve the microhardness of composite solders.

  14. Microstructurally based thermomechanical fatigue lifetime model of solder joints for electronic applications

    Energy Technology Data Exchange (ETDEWEB)

    Frear, D.R.; Rashid, M.M.; Burchett, S.N.

    1993-07-01

    We present a new methodology for predicting the fatigue life of solder joints for electronics applications. This approach involves integration of experimental and computational techniques. The first stage involves correlating the manufacturing and processing parameters with the starting microstructure of the solder joint. The second stage involves a series of experiments that characterize the evolution of the microstructure during thermal cycling. The third stage consists of a computer modeling and simulation effort that utilizes the starting microstructure and experimental data to produce a reliability prediction of the solder joint. This approach is an improvement over current methodologies because it incorporates the microstructure and properties of the solder directly into the model and allows these properties to evolve as the microstructure changes during fatigue.

  15. Interfacial Reactions and Joint Strengths of Sn- xZn Solders with Immersion Ag UBM

    Science.gov (United States)

    Jee, Y. K.; Yu, Jin

    2010-10-01

    The solder joint microstructures of immersion Ag with Sn- xZn ( x = 0 wt.%, 1 wt.%, 5 wt.%, and 9 wt.%) solders were analyzed and correlated with their drop impact reliability. Addition of 1 wt.% Zn to Sn did not change the interface microstructure and was only marginally effective. In comparison, the addition of 5 wt.% or 9 wt.% Zn formed layers of AgZn3/Ag5Zn8 at the solder joint interface, which increased drop reliability significantly. Under extensive aging, Ag-Zn intermetallic compounds (IMCs) transformed into Cu5Zn8 and Ag3Sn, and the drop impact resistance at the solder joints deteriorated up to a point. The beneficial role of Zn on immersion Ag pads was ascribed to the formation of Ag-Zn IMC layers, which were fairly resistant to the drop impact, and to the suppression of the brittle Cu6Sn5 phase at the joint interface.

  16. Populations of some molds in water-damaged homes may differ if the home was constructed with gypsum drywall compared to plaster

    Science.gov (United States)

    Starting in the 1940s, gypsum drywall began replacing plaster and lathe in the U.S. home construction industry. Our goal was to evaluate whether some mold populations differ in water- damaged homes primarily constructed with gypsum drywall compared to plaster. The dust samples fr...

  17. (AEDPH3)·(BtaH): a novel supramolecular plaster with formaldehyde adsorption and formaldehyde/ultraviolet ray-induced luminescence switching performance.

    Science.gov (United States)

    Chen, Shuo-ping; Hu, Le; Zhang, Yu-qin; Deng, Pu; Li, Cong; Chen, Xi; Yuan, Liang-jie

    2012-01-14

    A novel supramolecular plaster, (AEDPH(3))·(BtaH) (1), is synthesised and characterized. The supramolecular plaster is easy to synthesise and process, and displays good mechanical properties. It can adsorb and eliminate formaldehyde (HCHO) with high efficiency and exhibits very interesting HCHO/ultraviolet ray-induced luminescence switching.

  18. Populations of some molds in water-damaged homes may differ if the home was constructed with gypsum drywall compared to plaster

    Science.gov (United States)

    Starting in the 1940s, gypsum drywall began replacing plaster and lathe in the U.S. home construction industry. Our goal was to evaluate whether some mold populations differ in water- damaged homes primarily constructed with gypsum drywall compared to plaster. The dust samples fr...

  19. INDEXING AND INDEX FUNDS

    Directory of Open Access Journals (Sweden)

    HAKAN SARITAŞ

    2013-06-01

    Full Text Available Proponents of the efficient market hypothesis believe that active portfolio management is largely wasted effort and unlikely to justify the expenses incurred. Therefore, they advocate a passive investment strategy that makes no attempt to outsmart the market. One common strategy for passive management is indexing where a fund is designed to replicate the performance of a broad-based index of stocks and bonds. Traditionally, indexing was used by institutional investors, but today, the use of index funds proliferated among individual investors. Over the years, both international and domestic index funds have disproportionately outperformed the market more than the actively managed funds have.

  20. Treatment of localized neuropathic pain of different etiologies with the 5% lidocaine medicated plaster - a case series.

    Science.gov (United States)

    Likar, Rudolf; Demschar, Susanne; Kager, Ingo; Neuwersch, Stefan; Pipam, Wolfgang; Sittl, Reinhard

    2015-01-01

    To assess the efficacy and safety of the topical 5% lidocaine medicated plaster in the treatment of localized neuropathic pain. This was a case series at an Austrian pain clinic, using retrospective analysis. Data of 27 patients treated for localized neuropathic pain with the 5% lidocaine medicated plaster were retrospectively analyzed. Assessment included changes in overall pain intensity, in intensity of different pain qualities, and of hyperalgesia and allodynia, and changes in sleep quality. Patients (17 female, ten male; mean age 53.4±11.4 years) presented mainly with dorsalgia (16 patients) or postoperative/posttraumatic pain (seven patients); one patient suffered from both. The mean overall pain intensity prior to treatment with lidocaine medicated plaster was 8.4±1.2 on the 11-point Likert scale. In the majority of cases, the lidocaine plaster was applied concomitantly with preexisting pain medication (81.5% of the patients). During the 6-month observation period, overall mean pain intensity was reduced by almost 5 points (4.98) to 3.5±2.6. Substantial reductions were also observed for neuralgiform pain (5 points from 7.9±2.6 at baseline) and burning pain (3 points from 5.2±4.1). Sleep quality improved from 4.6±2.6 at baseline to 5.5±1.8. Stratification by pain diagnosis showed marked improvements in overall pain intensity for patients with dorsalgia or postoperative/posttraumatic pain. The lidocaine plaster was well tolerated. Overall, topical treatment with the 5% lidocaine medicated plaster was associated with effective pain relief and was well tolerated.

  1. Treatment of localized neuropathic pain of different etiologies with the 5% lidocaine medicated plaster – a case series

    Science.gov (United States)

    Likar, Rudolf; Demschar, Susanne; Kager, Ingo; Neuwersch, Stefan; Pipam, Wolfgang; Sittl, Reinhard

    2015-01-01

    Objective To assess the efficacy and safety of the topical 5% lidocaine medicated plaster in the treatment of localized neuropathic pain. Study design This was a case series at an Austrian pain clinic, using retrospective analysis. Patients and methods Data of 27 patients treated for localized neuropathic pain with the 5% lidocaine medicated plaster were retrospectively analyzed. Assessment included changes in overall pain intensity, in intensity of different pain qualities, and of hyperalgesia and allodynia, and changes in sleep quality. Results Patients (17 female, ten male; mean age 53.4±11.4 years) presented mainly with dorsalgia (16 patients) or postoperative/posttraumatic pain (seven patients); one patient suffered from both. The mean overall pain intensity prior to treatment with lidocaine medicated plaster was 8.4±1.2 on the 11-point Likert scale. In the majority of cases, the lidocaine plaster was applied concomitantly with preexisting pain medication (81.5% of the patients). During the 6-month observation period, overall mean pain intensity was reduced by almost 5 points (4.98) to 3.5±2.6. Substantial reductions were also observed for neuralgiform pain (5 points from 7.9±2.6 at baseline) and burning pain (3 points from 5.2±4.1). Sleep quality improved from 4.6±2.6 at baseline to 5.5±1.8. Stratification by pain diagnosis showed marked improvements in overall pain intensity for patients with dorsalgia or postoperative/posttraumatic pain. The lidocaine plaster was well tolerated. Conclusion Overall, topical treatment with the 5% lidocaine medicated plaster was associated with effective pain relief and was well tolerated. PMID:25565882

  2. Studies of intermetallic growth in Cu-solder systems and wettability at solid-liquid interfaces

    OpenAIRE

    Martin, Raymond W.

    1991-01-01

    Approved for public release; distribution is unlimited The metallurgical bond formed between tin-lead solder and the copper substrate is characterized by the formation of an intermetallic compound layer. The growth of the intermetallic layer is the result of competing mechanisms, growth of the intermetallic at the intermetallic/copper interface and its dissolution at the intermetallic/liquid solder interface. These were studied by determining the dissolution rates of the copper and the i...

  3. Joint Lead-Free Solder Test Program for High Reliability Military and Space Applications

    Science.gov (United States)

    Brown, Christina

    2004-01-01

    Current and future space and defense systems face potential risks from the continued use of tin-lead solder, including: compliance with current environmental regulations, concerns about potential environmental legislation banning lead-containing products, reduced mission readiness, and component obsolescence with lead surface finishes. For example, the United States Environmental Protection Agency (USEPA) has lowered the Toxic Chemical Release reporting threshold for lead to 100 pounds. Overseas, the Waste Electrical and Electronic Equipment (WEEE) and the Restriction on Hazardous Substances (RoHS) Dicctives in Europe and similar mandates in Japan have instilled concern that a legislative body will prohibit the use of lead in aerospace/military electronics soldering. Any potential banning of lead compounds could reduce the supplier base and adversely affect the readiness of missions led by the National Aeronautics and Space Administration (NASA) and the U.S. Department of Defense (DoD). Before considering lead-free electronics for system upgrades or future designs, however, it is important for the DoD and NASA to know whether lead-free solders can meet their systems' requirements. No single lead-free solder is likely to qualify for all defense and space applications. Therefore, it is important to validate alternative solders for discrete applications. As a result of the need for comprehensive test data on the reliability of lead-free solders, a partnership was formed between the DoD, NASA, and several original equipment manufactures (OEMs) to conduct solder-joint reliability (laboratory) testing of three lead-free solder alloys on newly manufactured and reworked circuit cards to generate performance data for high-reliability (IPC Class 3) applications.

  4. Thermomechanical cycling investigation of CU particulate and NITI reinforced lead-free solder

    OpenAIRE

    Horton, W. Scott.

    2006-01-01

    In todayâ s Flip Chip (FC) and Ball Grid Array (BGA) electronic packages solder joints provide both the electrical as well as the mechanical connections between the silicon chip and the substrate. Due to coefficient of thermal expansion (CTE) differences between the chip and substrate the solder joints undergo thermomechanical stresses and strains as an electronic package is heated and cooled with power on/off cycles. Advances in chip designs result in chips that are larger, run hotter and d...

  5. 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.

  6. Packaging of hard solder 500W QCW diode laser array

    Science.gov (United States)

    Li, Xiaoning; Wang, Jingwei; Hou, Dong; Nie, Zhiqiang; Liu, Xingsheng

    2016-03-01

    The package structure critically influences the major characteristics of diode laser, such as thermal behavior, output power, wavelength and smile effect. In this work, a novel micro channel cooler (MCC) for stack array laser with good heat dissipation capability and high reliability is presented. Numerical simulations of thermal management with different MCC structure are conducted and analyzed. Based on this new MCC packaging structure, a series of QCW 500W high power laser arrays with hard solder packaging technology has been fabricated. The performances of the laser arrays are characterized. A narrow spectrum of 3.12 nm and an excellent smile value are obtained. The lifetime of the laser array is more than 1.38×109 shots and still ongoing.

  7. Modeling of thermal processes in waveguide tracts induction soldering

    Science.gov (United States)

    Murygin, A. V.; Tynchenko, V. S.; Laptenok, V. D.; Emilova, O. A.; Seregin, Yu N.

    2017-02-01

    The problem solving of the induction heating models development, which describe the heating of the separate structural assembly components of the waveguide path and product generally, is presented in this paper. Proposed mathematical models are based on the thermodynamics equation and on the heat balance law. The system of the heating process mathematical models, such as surge tube and flange heating, and the mathematical model of the energy distribution are presented. During the modeling process with Matlab system by using mathematical models graphs of the tube, flange and coupling heating were obtained. These design charts are confirmed by the results of the experimental study. During the experimental studies pyrometers for temperature control and a video camera for visual control of the process parameters were used. On the basis of obtained models the induction soldering process features analysis is carried out and the need of its automation by the using of the information control systems for thermal management between the connection elements is revealed.

  8. 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.

  9. 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.

  10. Soldering in a Reduced Gravity Environment (SoRGE)

    Science.gov (United States)

    Easton, John W.; Struk, Peter M.

    2012-01-01

    Future long-duration human exploration missions will be challenged by constraints on mass and volume allocations available for spare parts. Addressing this challenge will be critical to the success of these missions. As a result, it is necessary to consider new approaches to spacecraft maintenance and repair that reduce the need for large replacement components. Currently, crew members on the International Space Station (ISS) recover from faults by removing and replacing, using backup systems, or living without the function of Orbital Replacement Units (ORUs). These ORUs are returned to a depot where the root cause of the failure is determined and the ORU is repaired. The crew has some limited repair capability with the Modulation/DeModulation (MDM) ORU, where circuit cards are removed and replace in faulty units. The next step to reducing the size of the items being replaced would be to implement component-level repair. This mode of repair has been implemented by the U.S. Navy in an operational environment and is now part of their standard approach for maintenance. It is appropriate to consider whether this approach can be adapted for future spaceflight operations. To this end, the Soldering in a Reduced Gravity Environment (SoRGE) experiment studied the effect of gravity on the formation of solder joints on electronic circuit boards. This document describes the SoRGE experiment, the analysis methods, and results to date. This document will also contain comments from the crew regarding their experience conducting the SoRGE experiment as well as recommendations for future improvements. Finally, this document will discuss the plans for the SoRGE samples which remain on ISS.

  11. Solder-Filling of a Cicc Cable for the Efda Dipole Magnet

    Science.gov (United States)

    Bauer, P.; Bruzzone, P.; Cau, F.; Weiss, K.; Portone, A.; Salpietro, E.; Vogel, M.; Vostner, A.

    2008-03-01

    Several prototype Cable-In-Conduit-Conductors (CICC) for the superconducting EDIPO (Efda DIPOle) revealed a degradation of their critical current (Ic) increasing with each loading cycle. The strong Lorentz-forces during operation in combination with the limited support of the single strands against these forces are thought to be the cause of the permanent degradation of the brittle Nb3Sn superconductor from which the multi-stranded CICC are made. In summer 2006 EFDA started to explore the possibility to remedy the Ic degradation by solder-filling the conductor in order to mechanically stabilize the twisted-strand cable inside the conduit. This solution was not considered as the main one, but as an emergency solution to be applied to the completed magnet, should every other option fail. The solder-filling approach was previously applied with success in some cases. Some issues, however, needed to be clarified before this solution could be proposed for the EDIPO project. The most important among them are the choice of solder material, details of the solder filling process, and the thermo-mechanical implications of a solder-filled, high-field, high-current cable. This work, being reported here, made use not only of simulation but also of experiments, such as the mechanical testing of solder filled cables at cryogenic temperatures.

  12. Preliminary Study on Synthesis of Organolead Halide with Lead Derived from Solder Wire

    Science.gov (United States)

    Pratiwi, P.; Rahmi, G. N.; Aimon, A. H.; Iskandar, F.; Abdullah, M.; Nuryadin, B. W.

    2016-08-01

    Organolead halide has attracted great attention for application in perovskite solar cells due to its high power conversion efficiency (PCE) of up to 20.1%. One of the most common perovskite materials is lead based reagent. In this research, we have synthesized organolead halide with lead extracted from solder wire. In the preparation procedure, first PbCl2 and PbI2 are produced by reacting lead from the solder wire with NaCl and KI, which are used as the basic substance for the perovskite material. Then, in order to get perovskite solution, the powders are reacted with methylamine iodide (MAI) in dimethylformamide (DMF) using a solution based method. Further, the spin coating method is used to fabricate perovskite thin film. The XRD peak results agreed with JCPDS Powder Diffraction of PbCl2 and PbI2. Based on FTIR, the transmittance spectra of the organolead mixed halide that was prepared using solder wire lead exhibited absorption peaks identical to organolead mixed halide using commercial lead. The UV-Vis absorbance spectra of the organolead mixed halide from solder wire lead also exhibited the same absorption ability as from commercial lead. Morever, EDS measurement showed that the element composition of the perovskite thin film using lead from solder wire identical to that from commercial lead. This indicates that solder wire lead is suitable enough for organolead halide material synthesis.

  13. Effect of Cu concentration on morphology of Sn-Ag-Cu solders by mechanical alloying

    Science.gov (United States)

    Kao, Szu-Tsung; Duh, Jenq-Gong

    2004-12-01

    The mechanical alloying (MA) process is considered an alternative approach to produce solder materials. In this study, the effect of Cu concentration in the ternary Sn-3.5Ag-xCu (x=0.2, 0.7, and 1) solder by MA was investigated. The (Cu,Sn) solid solution was precipitated as the Cu6Sn5 intermetallic compound (IMC), which was distributed nonuniformly through the microstructure. The Cu6Sn5 IMC, which was present in the SnAgCu solder with high Cu composition, causes the as-milled MA particle to fracture to a smaller size. Appreciable distinction on morphology of as-milled MA powders with different Cu content was revealed. When the Cu concentration was low (x=0.2), MA particle aggregated to a spherical ingot with large particle size. For higher Cu concentration (x=0.7 and x=1), the MA particle turned to flakes with smaller particle size. The distinction of the milling mechanism of Sn-3.5Ag-xCu (x=0.2, 0.7, and 1) solder by the MA process was discussed. An effective approach was developed to reduce the particle size of the SnAgCu solder from 1 mm down to 10-100 µm by doping the Cu6Sn5 nanoparticle during the MA process. In addition, the differential scanning calorimetry (DSC) results also ensure the compatibility to apply the solder material for the reflow process.

  14. Development of high strength Sn-Mg solder alloys with reasonable ductility

    Science.gov (United States)

    Alam, Md Ershadul; Gupta, Manoj

    2013-09-01

    This study discussed the development of a series of new lead-free Sn-Mg solders by incorporating varying amounts of Mg (0.8, 1.5 and 2.5 wt. %) into pure Sn using disintegrated melt deposition technique followed by room temperature extrusion. All extruded Sn and Sn-Mg solder samples were characterized. Microstructural characterization studies revealed equiaxed grain morphology, minimal porosity and relatively uniform distribution of secondary phase. Better coefficient of thermal expansion was observed for Sn-2.5Mg sample when compared to conventional Sn-37Pb solder. Melting temperature of Sn-1.5Mg was found to be 212°C which is much lower than the conventional Sn-Ag-Cu or Sn-Cu (227°C) solders. Microhardness was increased with increasing amount of Mg in pure Sn. Room temperature tensile test results revealed that newly developed Sn-Mg solders exhibit enhanced strengths (0.2% yield strength and ultimate tensile strength) with comparable (if not better) ductility when compared to other commercially available and widely used Sn-based solder alloys.

  15. Effect of interface microstructure on the mechanical properties of Pb-free hybrid microcircuit solder joints

    Energy Technology Data Exchange (ETDEWEB)

    Hernandez, C.L.; Vianco, P.T.; Rejent, J.A.

    1998-08-01

    Although Sn-Pb eutectic alloy is widely used as a joining material in the electronics industry, it has well documented environmental and toxicity issues. Sandia National Laboratories is developing alternative solder materials to replace traditional Pb-containing alloys. The alloys are based on the Sn-Ag, Sn-Ag-Bi and Sn-Ag-Bi-Au systems. Prototype hybrid microcircuit (HMC) test vehicles have been developed to evaluate these Pb-free solders, using Au-Pt-Pd thick film metallization. Populated test vehicles with surface mount devices have been designed and fabricated to evaluate the reliability of surface mount solder joints. The test components consist of a variety of dummy chip capacitors and leadless ceramic chip carriers (LCCC`s). Intermetallic compound (IMC) layer reaction products that form at the solder/substrate interface have been characterized and their respective growth kinetics quantified. Thicker IMC layers pose a potential reliability problem with solder joint integrity. Since the IMC layer is brittle, the likelihood of mechanical failure of a joint in service is increased. The effect of microstructure and the response of these different materials to wetting, aging and mechanical testing was also investigated. Solid-state reaction data for intermetallic formation and mechanical properties of the solder joints are reported.

  16. Mechanical properties of Pb-free solder alloys on thick film hybrid microcircuits

    Energy Technology Data Exchange (ETDEWEB)

    Hernandez, C.L.; Vianco, P.T.; Rejent, J.A.; Hosking, F.M.

    1998-03-10

    The technology drivers of the electronics industry continue to be systems miniaturization and reliability, in addition to addressing a variety of important environmental issues. Although the Sn-Pb eutectic alloy is widely used as a joining material in the electronics industry, it has drawn environmental concern due to its Pb content. The solder acts both as an electrical and mechanical connection within the different packaging levels in an electronic device. New Pb-free solders are being developed at Sandia National Laboratories. The alloys are based on the Sn-Ag alloy, having Bi and Au additions. Prototype hybrid microcircuit (HMC) test vehicles have been assembled to evaluate Pb-free solders for Au-Pt-Pd thick film soldering. The test components consist of a variety of dummy chip capacitors and leadless ceramic chip carriers (LCCC`s). The mechanical properties of the joints were evaluated. The reflow profiles and the solid state intermetallic formation reaction will also be presented. Improved solder joint manufacturability and increased fatigue resistance solder alloys are the goals of these materials.

  17. Numerical simulation of soldered joints and reliability analysis of PLCC components with J-shape leads

    Institute of Scientific and Technical Information of China (English)

    Zhang Liang; Xue Songbai; Lu Fangyan; Han Zongjie; Wang Jianxin

    2008-01-01

    This paper deals with a study on SnPb and lead-free soldered joint reliability of PLCC devices with different lead counts under three kinds of temperature cycle profiles, which is based on non-linear finite element method. By analyzing the stress of soldered joints, it is found that the largest stress is at the area between the soldered joints and the leads, and analysis results indicate that the von Mises stress at the location slightly increases with the increase of lead counts. For PLCC with 84 leads the soldered joints was modeled for three typical loading (273-398 K, 218-398 K and 198-398 K) in order to study the influence of acceleration factors on the reliability of soldered joints. And the estimation of equivalent plastic strain of three different lead-free solder alloys (Sn3.8Ag0.7Cu, Sn3.5Ag and Sn37Pb) was also carried out.

  18. 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.

  19. 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.

  20. Development of new multicomponent Sn–Ag–Cu–Bi lead-free solders for low-cost commercial electronic assembly

    Energy Technology Data Exchange (ETDEWEB)

    El-Daly, A.A., E-mail: dreldaly11@yahoo.com [Physics Department, Faculty of Science, Zagazig Univ., Zagazig (Egypt); Center of Nanotechnology, Zagazig Univ., Zagazig (Egypt); El-Taher, A.M. [Physics Department, Faculty of Science, Zagazig Univ., Zagazig (Egypt); Center of Nanotechnology, Zagazig Univ., Zagazig (Egypt); Gouda, S. [Physics Department, Faculty of Science, Zagazig Univ., Zagazig (Egypt)

    2015-04-05

    Highlights: • Small amounts of Bi have been added into Sn–1.5Ag–0.7Cu solder. • Bi reduced the undercooling and eutectic temperature of SAC257 solder. • Bi refined the microstructure and diminishes the nucleation rate of IMCs. • Bi increased the creep resistance and fracture lifetime of the solder. • Overall SAC properties can be improved adding not more than 3 wt.% Bi. - Abstract: Eutectic Sn–Ag–Cu (SAC) solder is one of the candidate alternatives to Sn–Pb-based solder alloys. The coupling effect of both minor alloying Bi addition and reducing the amount of Ag phase have been proposed as an important approach to optimize existing and to develop new SAC solders. Characteristics of new Sn–Ag–Cu–Bi solders were analyzed and compared with those of as-solidified Sn–1.5Ag–0.7Cu (SAC157) alloy. The results of differential scanning calorimetry (DSC) indicate significant reduction of both undercooling, eutectic temperature, solidus and liquidus temperatures with the addition of Bi into SAC(157) solder, although the pasty range remains the same or slightly increased. Moreover, SAC(157) solders containing Bi were found to have a higher creep resistance (126.1 times) than SAC(157) solder at the same stress level and testing temperature. The higher creep resistance was contributed by the solid solution and precipitations strengthen effects of Bi. The precipitation of these Bi atoms or particles can significantly refine the microstructure, blocks the movement of dislocations and increases the creep resistance of Bi-containing solders. The creep life time of plain SAC(157) alloy was extremely enlarged 23.7 times with the addition of 3 wt.% Bi. Constitutive Garofalo model of creep for both SAC(157) and Sn–Ag–Cu–Bi solders was assembled based on the experimental data.

  1. Compartment syndrome developed due to the plaster cast :Three cases report

    Directory of Open Access Journals (Sweden)

    Pinar Doruk

    2013-08-01

    Full Text Available Compartment syndrome can occur as a result of the complication of the plaster cast applications ,which are frequently used for fracture stabilization. This syndrome occurs due to increased compartment volume or shrinking of compartment area because of edema, hemorrage or high pressure of tissues. All of these mechanisms causes arteriolar compression, resulting nerve and muscle ischemia. Intensive and continuous pain is common and limits the motions of the patient and increases with passive stretching of the involved muscles. Swelling of limb, change in skin color, peripheral vasculatory failure symptoms such as pallor,weak arterial pulsation and as a result of peripheral nerve damage, sensorimotor deficit can also be observed. Clinical evaluation, measure of pressure within the compartment, and electroneuromyography (ENMG can be used for the diagnosis. In addition to treatment of to the treatment of etiology and pain, further treatment options such as fasciotomy, physiotherapy modalities, tendon transfers, can be performed. In this case report, we will discuss three patients with nerve lesions as a result of the compartment syndrome that developed due to the plaster casting of bone fractures. [Cukurova Med J 2013; 38(4.000: 774-778

  2. Consolidation of archaeological gypsum plaster by bacterial biomineralization of calcium carbonate.

    Science.gov (United States)

    Jroundi, Fadwa; Gonzalez-Muñoz, Maria Teresa; Garcia-Bueno, Ana; Rodriguez-Navarro, Carlos

    2014-09-01

    Gypsum plasterworks and decorative surfaces are easily degraded, especially when exposed to humidity, and thus they require protection and/or consolidation. However, the conservation of historical gypsum-based structural and decorative materials by conventional organic and inorganic consolidants shows limited efficacy. Here, a new method based on the bioconsolidation capacity of carbonatogenic bacteria inhabiting the material was assayed on historical gypsum plasters and compared with conventional consolidation treatments (ethyl silicate; methylacrylate-ethylmethacrylate copolymer and polyvinyl butyral). Conventional products do not reach in-depth consolidation, typically forming a thin impervious surface layer which blocks pores. In contrast, the bacterial treatment produces vaterite (CaCO3) biocement, which does not block pores and produces a good level of consolidation, both at the surface and in-depth, as shown by drilling resistance measurement system analyses. Transmission electron microscopy analyses show that bacterial vaterite cement formed via oriented aggregation of CaCO3 nanoparticles (∼20nm in size), resulting in mesocrystals which incorporate bacterial biopolymers. Such a biocomposite has superior mechanical properties, thus explaining the fact that drilling resistance of bioconsolidated gypsum plasters is within the range of inorganic calcite materials of equivalent porosity, despite the fact that the bacterial vaterite cement accounts for only a 0.02 solid volume fraction. Bacterial bioconsolidation is proposed for the effective consolidation of this type of material. The potential applications of bacterial calcium carbonate consolidation of gypsum biomaterials used as bone graft substitutes are discussed.

  3. Study on Solder Joint Reliability of Plastic Ball Grid Array Component Based on SMT Products Virtual Assembly Technology

    Institute of Scientific and Technical Information of China (English)

    HUANG Chunyue; WU Zhaohua; ZHOU Dejian

    2006-01-01

    Based on surface mount products virtual assembly technology, the solder joint reliability of plastic ball grid array (PBGA) was studied. Four process parameters, including the upper pad diameter,the stencil thickness, the chip weight on a single solder joint and the lower pad diameter were chose as four control factors. By using an L25(56) orthogonal array the PBGA solder joints which have 25 different process parameters' levels combinations were designed. The numerical models of all the 25 PBGA solder joints were developed and the finite element analysis models were setup. The stress and strain distribution within the PBGA solder joints under thermal cycles were studied by finite element analysis, and the thermal fatigue life of PBGA solder joint was calculated using Coffin-Manson equation. Based on the calculated thermal fatigue life results, the range analysis was performed. The results of study show that that the impact sequence of the four factors from high to low on the fatigue life of PBGA solder joints are the stencil thickness,the upper pad diameter, the lower pad diameter and the chip weight on a single solder joint; the best level combination ofprocess parameters that results in the longest fatigue life is the lower pad diameter of 0.6 mm, the stencil thickness of 0.175 mm, the chip weight on asingle solder joint of 28×10-5 N and the upper pad diameter of 0.5 mm.

  4. Effect of Lanthanum on Driving Force for Cu6Sn5 Growth and Improvement of Solder Joint Reliability

    Institute of Scientific and Technical Information of China (English)

    2002-01-01

    By means of adding low content of rare earth element La into Sn60-Pb40 solder alloy, the growth of Cu6Sn5 intermetallic compound at the interface of solder joint is hindered, and the thermal fatigue life of solder joint is increased by 2 times. The results of thermodynamic calculation based on diffusion kinetics show that, the driving force for Cu6Sn5 growth is lowered by adding small content of La in Sn60-Pb40 solder alloy. Meanwhile, there is an effective local mole fraction range of La, in which, 0.18% is the limited value and 0.08% is the best value.

  5. Effects of Aging Treatment on Mechanical Properties of Sn-58Bi Epoxy Solder on ENEPIG-Surface-Finished PCB

    Science.gov (United States)

    Kim, Jungsoo; Myung, Woo-Ram; Jung, Seung-Boo

    2016-11-01

    The mechanical properties of Sn-58Bi epoxy solder were evaluated by low-speed shear testing as functions of aging time and temperature. To determine the effects of epoxy, the interfacial reaction and mechanical properties of both Sn-58Bi and Sn-58Bi epoxy solder were investigated after aging treatment. The chemical composition and growth kinetics of the intermetallic compound (IMC) formed at the interface between Sn-58Bi solder and electroless nickel electroless palladium immersion gold (ENEPIG) surface finish were analyzed. Sn-58Bi solder paste was applied by stencil-printing on flame retardant-4 substrate, then reflowed. Reflowed samples were aged at 85°C, 95°C, 105°C, and 115°C for up to 1000 h. (Ni,Pd)3Sn4 IMC formed between Sn-58Bi solder and ENEPIG surface finish after reflow. Ni3Sn4 and Ni3P IMCs formed at the interface between (Ni,Pd)3Sn4 IMC and ENEPIG surface finish after aging at 115°C for 300 h. The overall IMC growth rate of Sn-58Bi solder joint was higher than that of Sn-58Bi epoxy solder joint during aging. The shear strength of Sn-58Bi epoxy solder was about 2.4 times higher than that of Sn-58Bi solder due to the blocking effect of epoxy, and the shear strength decreased with increasing aging time.

  6. Electrodeposition of lead-free, tin-based alloy solder films

    Science.gov (United States)

    Han, Chunfen

    The dominant materials used for solders in electronic assemblies over the past 60 years have been Pb-Sn alloys. Increasing pressure from environmental and health authorities has stimulated the development of various Pb-free solders. Two of the most promising replacements are eutectic Sn-Cu and Sn-Ag-Cu alloys that are produced primarily by electrodeposition. During soldering and solid state aging (storage or in service of the electronic assemblies), interactions take place at the solder/substrate metal interface and form intermetallic compounds (IMCs) which are crucial for the reliability of the solder joints. Simple and "green" Sn-citrate and Sn-Cu-citrate solutions have been developed and optimized to electrodeposit eutectic and near eutectic Sn-Cu solder films. Sn-citrate suspensions with Cu particles and Sn-Cu-citrate suspensions with Ag nano-particles have also been developed and optimized to allow for electrochemical composite deposition of eutectic and near eutectic Sn-Cu and Sn-Ag-Cu solder films. Different plating and post-plating conditions, including solution concentration, current density, agitation, additives, and aging, have been investigated by evaluating their effects on plating rate, deposit composition and microstructure. Tri-ammonium citrate is used as the only complexing agent for Sn, Sn-Cu, and Sn-Ag-Cu deposition. Speciation diagram calculations, reduction potential calculations, and polarization studies are conducted to study Sn-citrate solution chemistry and the kinetics of Sn electrodeposition. X-ray photoelectron spectroscopy (XPS) analysis is used to identify the precipitates formed in Sn-citrate solutions at low pH. Current-controlled and potential-controlled electrochemical techniques, nucleation modeling, and surface morphology characterization techniques are applied to study the nucleation and film growth mechanism of Sn and Sn-Cu electrodeposition from Sn-citrate and Sn-Cu-citrate solutions. Reflow and aging tests for deposited Sn

  7. Laser solder repair technique for nerve anastomosis: temperatures required for optimal tensile strength

    Science.gov (United States)

    McNally-Heintzelman, Karen M.; Dawes, Judith M.; Lauto, Antonio; Parker, Anthony E.; Owen, Earl R.; Piper, James A.

    1998-01-01

    Laser-assisted repair of nerves is often unsatisfactory and has a high failure rate. Two disadvantages of laser assisted procedures are low initial strength of the resulting anastomosis and thermal damage of tissue by laser heating. Temporary or permanent stay sutures are used and fluid solders have been proposed to increase the strength of the repair. These techniques, however, have their own disadvantages including foreign body reaction and difficulty of application. To address these problems solid protein solder strips have been developed for use in conjunction with a diode laser for nerve anastomosis. The protein helps to supplement the bond, especially in the acute healing phase up to five days post- operative. Indocyanine green dye is added to the protein solder to absorb a laser wavelength (approximately 800 nm) that is poorly absorbed by water and other bodily tissues. This reduces the collateral thermal damage typically associated with other laser techniques. An investigation of the feasibility of the laser-solder repair technique in terms of required laser irradiance, tensile strength of the repair, and solder and tissue temperature is reported here. The tensile strength of repaired nerves rose steadily with laser irradiance reaching a maximum of 105 plus or minus 10 N.cm-2 at 12.7 W.cm-2. When higher laser irradiances were used the tensile strength of the resulting bonds dropped. Histopathological analysis of the laser- soldered nerves, conducted immediately after surgery, showed the solder to have adhered well to the perineurial membrane, with minimal damage to the inner axons of the nerve. The maximum temperature reached at the solder surface and at the solder/nerve interface, measured using a non-contact fiber optic radiometer and thermocouple respectively, also rose steadily with laser irradiance. At 12.7 W.cm-2, the temperatures reached at the surface and at the interface were 85 plus or minus 4 and 68 plus or minus 4 degrees Celsius respectively

  8. Intermetallic compound formation at Sn-3.0Ag-0.5Cu-1.0Zn lead-free solder alloy/Cu interface during as-soldered and as-aged conditions

    Energy Technology Data Exchange (ETDEWEB)

    Wang, Feng-Jiang [Department of Materials Science and Engineering, Shanghai University of Engineering Science, Shanghai 201620 (China)]. E-mail: wangfjy@yahoo.com.cn; Yu, Zhi-Shui [Department of Materials Science and Engineering, Shanghai University of Engineering Science, Shanghai 201620 (China); Qi, Kai [Department of Materials Science and Engineering, Shanghai University of Engineering Science, Shanghai 201620 (China)

    2007-07-12

    Intermetallic formations of Sn-3.0Ag-0.5Cu solder alloy with additional 1.0 wt% Zn were investigated for Cu-substrate during soldering and isothermal aging. During soldering condition, the Cu{sub 5}Zn{sub 8} compound with granular-type morphology is the interfacial IMC for Sn-3.0Ag-0.5Cu-1.0Zn solder, while the Cu{sub 6}Sn{sub 5} compound with scallop-type morphology is the interfacial IMC for Sn-3.0Ag-0.5Cu solder. During thermal aging, the final interfacial structure for Sn-3.0Ag-0.5Cu-1.0Zn solder is solder/Cu{sub 5}Zn{sub 8}/Cu{sub 6}Sn{sub 5}/Cu{sub 3}Sn/Cu, different from the solder/Cu{sub 6}Sn{sub 5}/Cu{sub 3}Sn/Cu for Sn-3.0Ag-0.5Cu solder. The thickness of Cu-Sn IMC layers increases, while the thickness of Cu{sub 5}Zn{sub 8} compound layer decreases with increasing aging time due to the decomposition of the Cu{sub 5}Zn{sub 8} layer by the diffusion of Cu and Zn atoms into the solder and Cu{sub 6}Sn{sub 5} at higher aging temperature. For Sn-3.0Ag-0.5Cu-1.0Zn solder, at higher aging temperature of 150 or 175 {sup o}C, with the formation of Cu{sub 3}Sn at Cu{sub 6}Sn{sub 5}/Cu, Kirkendall voids can be observed at the interface of Cu{sub 3}Sn/Cu.

  9. Effect of diode-laser parameters on shear force of micro-joints soldered with Sn-Ag-Cu lead-free solder on Au/Ni/Cu pad

    Institute of Scientific and Technical Information of China (English)

    WANG Jian-xin; XUE Song-bai; FANG Dian-song; JU Jin-long; HAN Zong-jie; YAO Li-hua

    2006-01-01

    Soldering experiments with Sn-3.5Ag-0.5Cu lead-free solder on Au/Ni/Cu pad were carried out by means of diode-laser and IR reflow soldering methods respectively. The influence of different heating methods as well as output power of diode-laser on shear force of micro-joints was studied and the relationship between the shear force and microstructures of micro-joints was analyzed.The results indicate that the formation of intermetallic compound Ag3Sn is the key factor to affect the shear force and the fine eutectic network structures of micro-joints as well as the dispersion morphology of fine compound Ag3Sn, in which eutectic network band is responsible for the improvement of the shear force of micro-joints soldered with Sn-Ag-Cu lead-free solder. With the increases of output power of diode-laser, the shear force and the microstructures change obviously. The eutectic network structures of micro-joints soldered with diode-laser soldering method are more homogeneous and the grains of Ag3Sn compounds are finer in the range of near optimal output power than those soldered with IR reflow soldering method, so the shear force is also higher than that using IR reflow soldering method. When the output power value of diode-laser is about 41.0 W, the shear force exhibits the highest value that is 70% higher than that using IR reflow soldering method.

  10. Plaster Casts after Antique Sculpture: Their Role in the Elevation of Public Taste and in American Art Instruction.

    Science.gov (United States)

    McNutt, James K.

    1990-01-01

    Examines the social, ideological, and cultural forces in colonial United States when plaster casts of Grecian and Roman sculpture were introduced. Describes how they were used in U.S. public schools and art museums to transmit the cultural heritage at the end of the nineteenth century. (KM)

  11. [Clinical research of post-stroke motor aphasia treated with acupoint application of jieyu plaster combined with acupuncture].

    Science.gov (United States)

    Fei, Aihua; Cai, Shengchao; Xu, Bin

    2015-11-01

    To compare the difference in clinical efficacy on post-stroke motor aphasia among the combined therapy of acupoint application of jieyu plaster and acupuncture, simple acupuncture and simple acupoint application of jieyu plaster. Eighty-six patients of post-stroke motor aphasia were randomized into an acupuncture group (28 cases) , an acupoint application gruop (29 cases) and the combined therapy group (29 cases). In the acupuncture group, acupuncture was applied at the Speech No. 1 area and three-tongue needling points, once a day, 6 times a week. In the acupoint application group, jieyue plaster was applied to Yongquan (KI 1) and Laogong (PC 8), once a day, and the bilateral acupoints were selected alternatively. In the combined therapy group, the therapeutic methods of the first two groups were used in combination. The treatment lasted for 4 weeks in the three groups. The speech function score was observed and compared before and after treatment in the three groups and the efficacy was compared among the three groups. The total effective rate was 86.2% (25/29) in the combined therapy group, which was better than 67.9% (19/28) in the acupuncture group and 69.0% (20/29) in the acupoint application group (both P plaster and acupuncture apparently improves the speech function in the treatment of post-stroke motor aphasia and the efficacy is better than that of simple acupuncture or simple acupoint application.

  12. Comparison of the moulding ability of Plaster of Paris and polyester cast material in the healthy adult forearm.

    Science.gov (United States)

    Bullen, Michael; Kinealy, John; Blanchard, Romane; Rodda, Christine; Pivonka, Peter

    2017-08-16

    To quantify the moulding ability of Plaster of Paris and polyester cast materials as assessed by the novel use of peripheral quantitative computed tomography. A prospective crossover study was performed in 25 healthy volunteers aged 18-65 years. Participants' non-dominant wrist was immobilized using a synthetic polyester cast followed by a Plaster of Paris cast with three point moulding to simulate reduction of a dorsally angulated distal radius fracture. The novel use of peripheral quantitative computed tomography was used to measure the closeness of fit of each cast on an axial tomographic slice. Plaster of Paris casts were able to achieve a closer mould than polyester when measured between the bone and the cast (p=0.002), as well as between the skin and the cast (p=0.001). There was no difference when stratified on BMI. Using pQCT assessment, a closely moulded fit was able to be more consistently achieved when using Plaster of Paris when compared to polyester casts of the distal radius. III. Copyright © 2017 Elsevier Ltd. All rights reserved.

  13. Fifty Cases of Child Restless Syndrome Treated with the Integrated Method of Chinese Herbal Drugs and Auricular-Plaster Therapy

    Institute of Scientific and Technical Information of China (English)

    2005-01-01

    @@ Fifty cases of child restless syndrome were treated with oral administration of Chinese traditional herbal drugs plus auricular-plaster therapy from December 1998 to November 2001, and another 47 cases were treated with oral administration of methylphenidate as controls. The result is reported as follows.

  14. 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.

  15. Effects of Ga Addition on Interfacial Reactions Between Sn-Based Solders and Ni

    Science.gov (United States)

    Wang, Chao-Hong; Li, Kuan-Ting

    2016-07-01

    The use of Ga as a micro-alloying element in Sn-based solders can change the microstructure of solder joints to improve the mechanical properties, and even suppress the interfacial intermetallic compound (IMC) growth. This research investigated the effects of Ga addition (0.2-1 wt.%Ga) on the IMC formation and morphological evolution in the Sn-based solder joints with Ni substrate. In the soldering reaction at 250°C and with less than 0.2 wt.%Ga addition, the formed phase was Ni3Sn4. When the Ga addition increased to 0.5 wt.%, it changed to a thin Ni2Ga3 layer of ˜1 μm thick, which stably existed at the interface in the initial 1-h reaction. Subsequently, the whole Ni2Ga3 layer detached from the Ni substrate and drifted into the molten solder. The Ni3Sn4 phase became dominant in the later stage. Notably, the Ga addition significantly reduced the grain size of Ni3Sn4, resulting in the massive spalling of Ni3Sn4 grains. With 1 wt.%Ga addition, the Ni2Ga3 layer remained very thin with no significant growth, and it stably existed at the interface for more than 10 h. In addition, the solid-state reactions were examined at temperatures of 160°C to 200°C. With addition of 0.5 wt.%Ga, the Ni3Sn4 phase dominated the whole reaction. By contrast, with increasing to 1 wt.%Ga, only a thin Ni2Ga3 layer was found even after aging at 160°C for more than 1200 h. The 1 wt.%Ga addition in solder can effectively inhibit the Ni3Sn4 formation in soldering and the long-term aging process.

  16. High-Reliability Low-Ag-Content Sn-Ag-Cu Solder Joints for Electronics Applications

    Science.gov (United States)

    Shnawah, Dhafer Abdulameer; Said, Suhana Binti Mohd; Sabri, Mohd Faizul Mohd; Badruddin, Irfan Anjum; Che, Fa Xing

    2012-09-01

    Sn-Ag-Cu (SAC) alloy is currently recognized as the standard lead-free solder alloy for packaging of interconnects in the electronics industry, and high- Ag-content SAC alloys are the most popular choice. However, this choice has been encumbered by the fragility of the solder joints that has been observed in drop testing as well as the high cost of the Ag itself. Therefore, low-Ag-content SAC alloy was considered as a solution for both issues. However, this approach may compromise the thermal-cycling performance of the solders. Therefore, to enhance the thermal-cycling reliability of low-Ag-content SAC alloys without sacrificing their drop-impact performance, alloying elements such as Mn, Ce, Ti, Bi, In, Sb, Ni, Zn, Al, Fe, and Co were selected as additions to these alloys. However, research reports related to these modified SAC alloys are limited. To address this paucity, the present study reviews the effect of these minor alloying elements on the solder joint reliability of low-Ag-content SAC alloys in terms of thermal cycling and drop impact. Addition of Mn, Ce, Bi, and Ni to low-Ag-content SAC solder effectively improves the thermal-cycling reliability of joints without sacrificing the drop-impact performance. Taking into consideration the improvement in the bulk alloy microstructure and mechanical properties, wetting properties, and growth suppression of the interface intermetallic compound (IMC) layers, addition of Ti, In, Sb, Zn, Al, Fe, and Co to low-Ag-content SAC solder has the potential to improve the thermal-cycling reliability of joints without sacrificing the drop-impact performance. Consequently, further investigations of both thermal-cycling and drop reliability of these modified solder joints must be carried out in future work.

  17. EFFECTS OF LEAD WIDTHS AND PITCHES ON RELIABILITY OF QUAD FLAT PACKAGE (QFP) SOLDERED JOINTS

    Institute of Scientific and Technical Information of China (English)

    XUE Songbai; WU Yuxiu; HAN Zongjie; WANG Jianxin

    2007-01-01

    The finite element method(FEM) is used to analyze the effects of lead widths and pitches on reliability of soldered joints. The optimum Simulation for QFP devices is also researched. The results indicate that when the lead pitches are the same, the maximum equivalent stress of the soldered joints increases with the increasing of lead widths, while the reliability of the soldered joints reduces. When the lead widths are the same, the maximum equivalent stress of the soldered joints doesn't decrease completely with the increasing of lead pitches, a minimum value of the maximum equivalent stress values exists in all the curves. Under this condition the maximum equivalent stress of the soldered joints is relatively the least, the reliability of soldered joints is high and the assembly is excellent. The simulating results indicate the best parameter: The lead width is 0.2 mm and lead pitch is 0.3 mm (the distance between two leads is 0.1 mm), which are benefited for the micromation of QFP devices now. The minimum value of the maximum equivalent stress of soldered joints exists while lead width is 0.25 mm and lead pitch is 0.35 mm (the distance between two leads is 0.1 mm), the devices can serve for a long time and the reliability is the highest, the assembly is excellent. The simulating results also indicate the fact that the lead width is 0.15 mm and lead pitch is 0.2 mm maybe the limit of QFP, which is significant for the high lead count and micromation of assembly.

  18. 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.

  19. Effects of Ga Addition on Interfacial Reactions Between Sn-Based Solders and Ni

    Science.gov (United States)

    Wang, Chao-Hong; Li, Kuan-Ting

    2016-12-01

    The use of Ga as a micro-alloying element in Sn-based solders can change the microstructure of solder joints to improve the mechanical properties, and even suppress the interfacial intermetallic compound (IMC) growth. This research investigated the effects of Ga addition (0.2-1 wt.%Ga) on the IMC formation and morphological evolution in the Sn-based solder joints with Ni substrate. In the soldering reaction at 250°C and with less than 0.2 wt.%Ga addition, the formed phase was Ni3Sn4. When the Ga addition increased to 0.5 wt.%, it changed to a thin Ni2Ga3 layer of ˜1 μm thick, which stably existed at the interface in the initial 1-h reaction. Subsequently, the whole Ni2Ga3 layer detached from the Ni substrate and drifted into the molten solder. The Ni3Sn4 phase became dominant in the later stage. Notably, the Ga addition significantly reduced the grain size of Ni3Sn4, resulting in the massive spalling of Ni3Sn4 grains. With 1 wt.%Ga addition, the Ni2Ga3 layer remained very thin with no significant growth, and it stably existed at the interface for more than 10 h. In addition, the solid-state reactions were examined at temperatures of 160°C to 200°C. With addition of 0.5 wt.%Ga, the Ni3Sn4 phase dominated the whole reaction. By contrast, with increasing to 1 wt.%Ga, only a thin Ni2Ga3 layer was found even after aging at 160°C for more than 1200 h. The 1 wt.%Ga addition in solder can effectively inhibit the Ni3Sn4 formation in soldering and the long-term aging process.

  20. Stable carbon and oxygen isotope investigation in historical lime mortar and plaster - Results from field and experimental study

    Energy Technology Data Exchange (ETDEWEB)

    Kosednar-Legenstein, B. [Institute of Applied Geosciences, Graz University of Technology, Rechbauerstrasse 12, A-8010 Graz (Austria); Dietzel, M. [Institute of Applied Geosciences, Graz University of Technology, Rechbauerstrasse 12, A-8010 Graz (Austria)], E-mail: martin.dietzel@tugraz.at; Leis, A. [Institute of Water Resources Management, Hydrogeology and Geophysics, Joanneum Research, Elisabethstrasse 16/II, A-8010 Graz (Austria); Stingl, K. [Institute of Applied Geosciences, Graz University of Technology, Rechbauerstrasse 12, A-8010 Graz (Austria)

    2008-08-15

    Lime mortar and plaster were sampled from Roman, medieval and early modern buildings in Styria. The historical lime mortar and plaster consist of calcite formed in the matrix during setting and various aggregates. The stable C and O isotopic composition of the calcite matrix was analyzed to get knowledge about the environmental conditions during calcite formation. The {delta}{sup 13}C{sub matrix} and {delta}{sup 18}O{sub matrix} values range from -31 to 0 per mille and -26 to -3 per mille (VPDB), respectively. Obviously, such a range of isotope values does not represent the local natural limestone assumed to be used for producing the mortar and plaster. In an ideal case, the calcite matrix in lime mortar and plaster is isotopically lighter in the exterior vs. the interior mortar layer according to the relationship {delta}{sup 18}O{sub matrix} = 0.61 . {delta}{sup 13}C{sub matrix} - 3.3 (VPDB). Calcite precipitation by uptake of gaseous CO{sub 2} into alkaline Ca(OH){sub 2} solutions shows a similar relationship, {delta}{sup 18}O{sub calcite} = 0.67 . {delta}{sup 13}C{sub calcite} - 6.4 (VPDB). Both relationships indicate that the {sup 13}C/{sup 12}C and {sup 18}O/{sup 16}O values of the calcite reflect the setting behaviour of the lime mortar and plaster. Initially, CO{sub 2} from the atmosphere is fixed as calcite, which is accompanied by kinetic isotope fractionation mostly due to the hydroxylation of CO{sub 2} ({delta}{sup 13}C{sub matrix} {approx} -25 per mille and {delta}{sup 18}O{sub matrix} {approx} -20 per mille ). As calcite formation continued the remaining gaseous CO{sub 2} is subsequently enriched in {sup 13}C and {sup 18}O causing later formed calcite to be isotopically heavier along the setting path in the matrix. Deviations from such an ideal isotopic behaviour may be due to the evolution of H{sub 2}O, e.g. evaporation, the source of CO{sub 2}, e.g. from biogenic origin, relicts of the natural limestone, and secondary effects, such as

  1. Treatment of localized neuropathic pain of different etiologies with the 5% lidocaine medicated plaster – a case series

    Directory of Open Access Journals (Sweden)

    Likar R

    2014-12-01

    Full Text Available Rudolf Likar,1 Susanne Demschar,1 Ingo Kager,1 Stefan Neuwersch,1 Wolfgang Pipam,1 Reinhard Sittl2 1Department of Anesthesiology and Intensive Care, Hospital Klagenfurt, Klagenfurt, Austria; 2Department of Anesthesiology, Interdisciplinary Pain Centre, University Hospital Erlangen, Erlangen, Germany Objective: To assess the efficacy and safety of the topical 5% lidocaine medicated plaster in the treatment of localized neuropathic pain. Study design: This was a case series at an Austrian pain clinic, using retrospective analysis. Patients and methods: Data of 27 patients treated for localized neuropathic pain with the 5% lidocaine medicated plaster were retrospectively analyzed. Assessment included changes in overall pain intensity, in intensity of different pain qualities, and of hyperalgesia and allodynia, and changes in sleep quality. Results: Patients (17 female, ten male; mean age 53.4±11.4 years presented mainly with dorsalgia (16 patients or postoperative/posttraumatic pain (seven patients; one patient suffered from both. The mean overall pain intensity prior to treatment with lidocaine medicated plaster was 8.4±1.2 on the 11-point Likert scale. In the majority of cases, the lidocaine plaster was applied concomitantly with preexisting pain medication (81.5% of the patients. During the 6-month observation period, overall mean pain intensity was reduced by almost 5 points (4.98 to 3.5±2.6. Substantial reductions were also observed for neuralgiform pain (5 points from 7.9±2.6 at baseline and burning pain (3 points from 5.2±4.1. Sleep quality improved from 4.6±2.6 at baseline to 5.5±1.8. Stratification by pain diagnosis showed marked improvements in overall pain intensity for patients with dorsalgia or postoperative/posttraumatic pain. The lidocaine plaster was well tolerated. Conclusion: Overall, topical treatment with the 5% lidocaine medicated plaster was associated with effective pain relief and was well tolerated. Keywords

  2. Mechanical Properties and Microstructure Investigation of Lead Free Solder

    Science.gov (United States)

    Wang, Qing; Gail, William F.; Johnson, R. Wayne; Strickland, Mark; Blanche, Jim

    2005-01-01

    While the electronics industry appears to be focusing on Sn-Ag-Cu as the alloy of choice for lead free electronics assembly, ,the exact composition varies by geographic region, supplier and user. Add to that dissolved copper and silver from the printed circuit board traces and surface finish, and there can be significant variation in the final solder joint composition. A systematic study of the mechanical and microstructural properties of Sn-Ag-Cu alloys with Ag varying from 2wt% to 4wt% and Cu varying from 0.5wt% to lSwt%, was undertaken in this research study. Different sample preparation techniques (water quenched, oil quenched and water quenched followed by reflow) were explored and the resulting microstructure compared to that of a typical reflowed lead free chip scale package (CSP) solder joint. Tensile properties (modulus, 0.2% yield strength and the ultimate tensile strength) and creep behavior of selected alloy compositions (Sn-4Ag-1 X u , Sn-4Ag-OSCu, Sn- 2Ag-1 X u , Sn-2Ag-OSCu, Sn-3.5Ag-O.SCu) were determined for three conditions: as- cast; aged for 100 hours at 125OC; and aged for 250 hours at 125OC. There was no significant difference in Young's Modulus as a function of alloy composition. After an initial decrease in modulus after 100 hours at 125"C, there was an insignificant change with further aging. The distribution of 0.2% strain yield stress and ultimate tensile strength as a function of alloy composition was more significant and decreased with aging time and temperature. The microstructures of these alloys were examined using light and scanning electron microscopy (LM and SEM) respectively and SEM based energy dispersive x-ray spectroscopy (EDS). Fracture surface and cross-section analysis were performed on the specimens after creep testing. The creep testing results and the effect of high temperature aging on mechanical properties is presented for the oil quenched samples. In general the microstructure of oil quenched specimen exhibited a

  3. [Case-control study on the treatmentof the fifth metatarsal base fractures by cardboard compression pad versus short leg plaster].

    Science.gov (United States)

    Xu, Ying-peng; Xie, Li-min; Xu, Chao; Zhang, Yue; Li, Yu-bin; Qiao, Xin

    2014-10-01

    To compare the effect,safety,and advantage of flexible fixation with paperboard and pad versus short leg plaster in treating the fifth metatarsal base fracture,and establish the standard of diagnosis and treatment of the fifth metatarsal base fractures in flexible fixation with paperboard and pad. From June 2010 to March 2013,59 patients with the fifth metatarsal base fracture were treated with paperboard and pad fixation or short leg plaster. Patients were enrolled and divided into paperboard and pad treatment group (paperboard group) and short leg plaster treatment group (plaster group) randomly according to the random number table. In paperboard group,there were 29 cases including 9 males and 20 females with an average age of (51.79±11.40) years old; the average course of injury was (11.59±6.58) hours. In plaster group, there were 30 cases including 9 males and 21 females with an average age of (52.13+17.34) years old ;the average course of injury was (11.03±7.06) hours. According to whether the fracture line across the articular surface, in paperboard group there were 14 cases of type A,15 of type B; in plaster group,16 of type A, 14 of type B. According to the degree of dislocation,in paperboard group there were 16 cases of degree I ,13 of degree II ; in plaster group,20 were degree I ,10 were degree II. Fracture was restored according to the type in manual. Patients in paperboard group were treated with paperboard and pad, and patients in plaster group were treated with short leg plaster. Fracture was fixed for 4 to 6 weeks according to fracture healing. On the 2nd, 4th,6th, 8th week and 3rd, 6th month after fixation, patients were followed up, and the foot function score was used to evaluate the function of injured foot. X-ray of injured foot was taken on the 2nd, 4th, 6th and 8th week were used to assess fracture healing. All patients got complete follow-up. The X-ray result showed that all fracture reached at clinical healing on the 8th week after

  4. Oxidation kinetics of thin copper films and wetting behaviour of copper and Organic Solderability Preservatives (OSP) with lead-free solder

    Energy Technology Data Exchange (ETDEWEB)

    Ramirez, Mauricio, E-mail: mauricio.ramirez2@de.bosch.com [Robert Bosch GmbH, Robert-Bosch-Strasse 2, 71701 Schwieberdingen (Germany); Chair for Surface Science and Corrosion, University of Erlangen-Nuremberg, Martensstrasse 7, 91058 Erlangen (Germany); Henneken, Lothar [Robert Bosch GmbH, Robert-Bosch-Strasse 2, 71701 Schwieberdingen (Germany); Virtanen, Sannakaisa [Chair for Surface Science and Corrosion, University of Erlangen-Nuremberg, Martensstrasse 7, 91058 Erlangen (Germany)

    2011-05-15

    The oxide formation on thin copper films deposited on Si wafer was studied by XPS, SEM and Sequential Electrochemical Reduction Analysis SERA. The surfaces were oxidized in air with a reflow oven as used in electronic assembly at temperatures of 100 deg. C, 155 deg. C, 200 deg. C, 230 deg. C and 260 deg. C. The SERA analyses detected only the formation of Cu{sub 2}O but the XPS analysis done for the calibration of the SERA equipment proved also the presence of a CuO layer smaller than 2 nm above the Cu{sub 2}O oxide. The oxide growth follows a power-law dependence on time within this temperature range and an activation energy of 33.1 kJ/mol was obtained. The wettability of these surfaces was also determined by measuring the contact angle between solder and copper substrate after the soldering process. A correlation between oxide thickness and wetting angle was established. It was found that the wetting is acceptable only when the oxide thickness is smaller than 16 nm. An activation energy of 27 kJ/mol was acquired for the spreading of lead free solder on oxidized copper surfaces. From wetting tests on copper surfaces protected by Organic Solderability Preservatives (OSP), it was possible to calculate the activation energy for the thermal decomposition of these protective layers.

  5. 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

    2016-08-01

    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.

  6. Clinical Observations on the Treatment of Migraine by Acupuncture plus Auricular Plaster Therapy

    Institute of Scientific and Technical Information of China (English)

    孙培华

    2007-01-01

    目的:探讨针刺配合耳压辨证治疗偏头痛的临床疗效.方法:将150例偏头痛患者随机分为观察组(n=90)和对照组(n=60).观察组患者采用针刺配合耳压辨证治疗,对照组患者采用口服西比灵治疗,并将两组的治疗效果进行对比观察.结果:观察组总有效率为94.4%,好于对照组(73.3%),观察组痊愈率为87.8%,高于对照组(55.0%).两组差异有非常显著意义(P<0.01).结论:观察组疗效明显优于对照组,运用针刺配合耳压辨证治疗偏头痛,能获得良好的临床疗效.%Objective: To investigate the clinical efficacy of acupuncture plus auricular plaster therapy for treating migraine. Methods: One hundred and fifty migraine patients were randomly allocated to an observation group (n=90) and a control group (n=60). The observation group were treated by acupuncture plus auricular plaster therapy based on syndrome differentiation and the control group, by oral administration of Flunarizine. The curative effects were compared between the two groups. Results: The total efficacy rate was 94.4% in the observation group and higher than in the control group (73.3%). The recovery rate was 87.8% in the observation group and higher than in the control group (55.0%). There were significant differences between the two groups (both P<0.01). The curative effect was significantly better in the observation group than in the control group. Conclusion: Clinically, acupuncture plus auricular plaster therapy based on syndrome differentiation has a good effect on migraine.

  7. Salt damage of stone, plaster and painted layers at a medieval church, South-Hungary

    Science.gov (United States)

    Török, Ákos; Galambos, Éva

    2016-04-01

    The Chapel of Pécsvárad is one of the best preserved and oldest medieval stone monument in South Hungary. It dates back to the 11th century. The interior of the chapel is decorated with wall paintings, which are later and probably originating from the late 12th century. The wall painting is partly preserved and it is located on an interior stone wall of the chapel facing to the East. The wall painting shows various forms of damage from salt efflorescence to chipping. The current research provides information on the in situ and laboratory analyses of salts, plasters, pigments and stone material suggesting mechanisms of decay that lead to partial loss of the painting. Both on site techniques and laboratory analyses were performed. Imaging techniques such as UV luminescence and IR thermography were used to identify the moist and salt covered zones on the wall surface. Portable moisture meter were also applied to map the wet zones in the interior and also at the external part of the chapel. Schmidt hammer and Duroscop were used for testing the surface strength of stone. Laboratory tests were focused on mineralogical and chemical compositional analyses. Small samples of stone, mortar, plaster and pigments were tested by optical microscopy, SEM-EDX, XRD and Thermogravimetric analyses. According to our tests the chapel was predominantly made of porous limestone and sandstone. Laboratory analyses proved that the major salt responsible for the damage of external walls are gypsum and halite, while in the interior part higher amount of halite and significant amount of sodium-nitrate were found besides gypsum. The painted layers are on Byzantine-type of plaster with organic compounds (plant fragments) and with a substrate layer rich in calcium carbonate. The identified pigments are dominantly earth pigments such as iron-oxide containing red and yellow (ochre) and green earth. A unique preservation of ultramarine blue in Hungary was found on the wall painting. The partial

  8. Pregabalin, the lidocaine plaster and duloxetine in patients with refractory neuropathic pain: a systematic review

    Directory of Open Access Journals (Sweden)

    Budhia Sangeeta

    2010-11-01

    Full Text Available Abstract Background Patients frequently fail to receive adequate pain relief from, or are intolerant of, first-line therapies prescribed for neuropathic pain (NeP. This refractory chronic pain causes psychological distress and impacts patient quality of life. Published literature for treatment in refractory patients is sparse and often published as conference abstracts only. The aim of this study was to identify published data for three pharmacological treatments: pregabalin, lidocaine plaster, and duloxetine, which are typically used at 2nd line or later in UK patients with neuropathic pain. Methods A systematic review of the literature databases MEDLINE, EMBASE and CCTR was carried out and supplemented with extensive conference and grey literature searching. Studies of any design (except single patient case studies that enrolled adult patients with refractory NeP were included in the review and qualitatively assessed. Results Seventeen studies were included in the review: nine of pregabalin, seven of the lidocaine plaster, and one of duloxetine. No head-to-head studies of these treatments were identified. Only six studies included treatments within UK licensed indications and dose ranges. Reported efficacy outcomes were not consistent between studies. Pain scores were most commonly assessed in studies including pregabalin; trials of pregabalin and the lidocaine plaster reported the proportion of responders. Significant improvements in the total, sensory and affective scores of the Short-form McGill Pain Questionnaire, and in function interference, sleep interference and pain associated distress, were associated with pregabalin treatment; limited or no quality of life data were available for the other two interventions. Limitations to the review are the small number of included studies, which are generally small, of poor quality and heterogeneous in patient population and study design. Conclusions Little evidence is available relevant to the

  9. The Americleft Project: Plaster Dental Casts Versus Digital Images for GOSLON Yardstick Ratings When Used in Intercenter Comparisons.

    Science.gov (United States)

    Long, Ross E; Daskalogiannakis, John; Mercado, Ana M; Hathaway, Ronald R; Fessler, Jennifer; Russell, Kathleen A

    2017-07-01

    The purpose of this investigation was to determine reliability and validity of GOSLON Yardstick ratings using plaster casts versus photo galleries of digital images in actual intercenter comparisons. The dental arch relationships of 112 patients with complete unilateral cleft lip and palate from 3 North American cleft/craniofacial centers were rated in 2 separate studies. In the first, plaster casts were used. For a later intercenter comparison, the same dental casts were scanned, digital bases added, and two-dimensional photographic galleries (6 views) were created for each set of casts. Three raters experienced with the GOSLON Yardstick carried out 2 separate ratings of the plaster casts in the first study, then of the photographic gallery of scanned digital images of the same casts in the second study. Inter- and intrarater reliabilities were calculated using the Weighted Kappa statistic. Average scores for each patient were calculated and compared between methods with correlation statistics and a Bland-Altman plot. Kruskal-Wallis test was used to compare results between centers using both media. Reliability using both methods was very good and comparable between methods. Mean weighted Kappas were: inter-rater = 0.815 (plaster) versus 0.891 (photo); and intrarater = 0.866 (plaster) versus 0.891 (photo). There was a highly significant correlation (r = 0.920). Mean difference between centers was 0.033 of a GOSLON category. The level of significance of the differences found between centers with both methods was identical, confirming the interchangeability of both media presentations.

  10. CO₂ laser welding of corneal cuts with albumin solder using radiometric temperature control.

    Science.gov (United States)

    Strassmann, Eyal; Livny, Eitan; Loya, Nino; Kariv, Noam; Ravid, Avi; Katzir, Abraham; Gaton, Dan D

    2013-01-01

    To examine the efficacy and reproducibility of CO₂ laser soldering of corneal cuts using real-time infrared fiber-optic radiometric control of tissue temperature in bovine eyes (in vitro) and to evaluate the duration of this procedure in rabbit eyes (in vivo). In vitro experiment: a 6-mm central perforating cut was induced in 40 fresh bovine eyes and sealed with a CO₂ laser, with or without albumin soldering, following placement of a single approximating nylon suture. A fiber-optic radiometric temperature control system for the CO₂ laser was used. Leaking pressure and histological findings were analyzed and compared between groups. In vivo experiment: following creation of a central perforation, 6 rabbit eyes were treated with a CO₂ laser with albumin solder and 6 rabbit eyes were treated with 10-0 nylon sutures. The amount of time needed for completion of the procedures was compared. In vitro experiment: effective sealing was achieved by CO₂ laser soldering. Mean (± SD) leaking pressure was 109 ± 30 mm Hg in the bovine corneas treated by the laser with albumin solder compared to 51 ± 7 mm Hg in the sutured control eyes (n = 10 each; p laser without albumin solder (48 ± 12 mm Hg) and in the cuts sealed only with albumin without laser welding (6.3 ± 4 mm Hg) than in the cuts treated with laser welding and albumin solder. In vivo experiment: mean surgical time was 140 ± 17 s in the laser-treated rabbits compared to 330 ± 30 s in the sutured controls (n = 6; p laser soldering revealed sealed corneal edges with a small gap bridged by coagulated albumin. The inflammatory reaction was minimal in contrast to the sutured controls. No thermal damage was detected at the wound edges. CO₂ laser soldering combined with the fiber-optic radiometer is an effective, reliable, and rapid tool for the closure of corneal wounds, and holds advantages over conventional suturing in terms of leaking pressure and surgical time. Copyright © 2013 S. Karger AG, Basel.

  11. Mechanical Shock Behavior of Environmentally-Benign Lead-free Solders

    Science.gov (United States)

    Yazzie, Kyle

    The mechanical behavior of Pb-free solder alloys is important, since they must maintain mechanical integrity under thermomechanical fatigue, creep, and mechanical shock conditions. Mechanical shock, in particular, has become an increasing concern in the electronics industry, since electronic packages can be subjected to mechanical shock by mishandling during manufacture or by accidental dropping. In this study, the mechanical shock behavior of Sn and Sn-Ag-Cu alloys was systematically analyzed over the strain rate range 10-3 -- 30 s-1 in bulk samples, and over 10-3 -- 12 s-1 on the single solder joint level. More importantly, the influences of solder microstructure and intermetallic compounds (IMC) on mechanical shock resistance were quantified. A thorough microstructural characterization of Sn-rich alloys was conducted using synchrotron x-ray computed tomography. The three-dimensional morphology and distribution of contiguous phases and precipitates was analyzed. A multiscale approach was utilized to characterize Sn-rich phases on the microscale with x-ray tomography and focused ion beam tomography to characterize nanoscale precipitates. A high strain rate servohydraulic test system was developed in conjunction with a modified tensile specimen geometry and a high speed camera for quantifying deformation. The effect of microstructure and applied strain rate on the local strain and strain rate distributions were quantified using digital image correlation. Necking behavior was analyzed using a novel mirror fixture, and the triaxial stresses associated with necking were corrected using a self-consistent method to obtain the true stress-true strain constitutive behavior. Fracture mechanisms were quantified as a function of strain rate. Finally, the relationship between solder microstructure and intermetallic compound layer thickness with the mechanical shock resistance of Sn-3.8Ag-0.7Cu solder joints was characterized. It was found that at low strain rates the dynamic

  12. 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...

  13. The influence of heat treatment on properties of lead-free solders

    Directory of Open Access Journals (Sweden)

    Lýdia Trnková Rízeková

    2015-02-01

    Full Text Available The article is focused on the analysis of degradation of properties of two eutectic lead-free solders SnCu0.7 and SnAg3.5Cu0.7. The microstructures of the intermetallic compound (IMC layers at the copper substrate - solder interface were examined before and after heat treatment at 150°C for 50, 200, 500 and 1000 hours. The thickness of IMC layers of the Cu6Sn5 phase was growing with the increasing time of annealing and shown the typical scallops. For the heat treatment times of 200 hours and longer, the Cu3Sn IMC layers located near the Cu substrate were also observed. The experiments showed there is a link between the thickness of IMC layers and decrease of the shear strength of solder joints. In general, the joints made of the ternary solder showed higher shear strength before and after heat treatment in comparison to joints from solder SnCu0.7.

  14. Interfacial Reaction and Die Attach Properties of Zn-Sn High-Temperature Solders

    Science.gov (United States)

    Kim, Seongjun; Kim, Keun-Soo; Kim, Sun-Sik; Suganuma, Katsuaki

    2009-02-01

    Interfacial reaction and die attach properties of Zn- xSn ( x = 20 wt.%, 30 wt.%, and 40 wt.%) solders on an aluminum nitride-direct bonded copper substrate were investigated. At the interface with Si die coated with Au/TiN thin layers, the TiN layer did not react with the solder and worked as a good protective layer. At the interface with Cu, CuZn5, and Cu5Zn8 IMC layers were formed, the thicknesses of which can be controlled by joining conditions such as peak temperature and holding time. During multiple reflow treatments at 260°C, the die attach structure was quite stable. The shear strength of the Cu/solder/Cu joint with Zn-Sn solder was about 30 MPa to 34 MPa, which was higher than that of Pb-5Sn solder (26 MPa). The thermal conductivity of Zn-Sn alloys of 100 W/m K to 106 W/m K was sufficiently high and superior to those of Au-20Sn (59 W/m K) and Pb-5Sn (35 W/m K).

  15. Application of robust color composite fringe in flip-chip solder bump 3-D measurement

    Science.gov (United States)

    Kuo, Chung-Feng Jeffrey; Wu, Han-Cheng

    2017-04-01

    This study developed a 3-D measurement system based on flip-chip solder bump, used fringes with different modulation intensities in color channels, in order to produce color composite fringe with robustness, and proposed a multi-channel composite phase unwrapping algorithm, which uses fringe modulation weights of different channels to recombine the phase information for better measurement accuracy and stability. The experimental results showed that the average measurement accuracy is 0.43μm and the standard deviation is 1.38 μm. The results thus proved that the proposed 3-D measurement system is effective in measuring a plane with a height of 50 μm. In the flip-chip solder bump measuring experiment, different fringe modulation configurations were tested to overcome the problem of reflective coefficient between the flip-chip base board and the solder bump. The proposed system has a good measurement results and robust stability in the solder bump measurement, and can be used for the measurement of 3-D information for micron flip-chip solder bump application.

  16. Effect of Plasma Surface Finish on Wettability and Mechanical Properties of SAC305 Solder Joints

    Science.gov (United States)

    Kim, Kyoung-Ho; Koike, Junichi; Yoon, Jeong-Won; Yoo, Sehoon

    2016-12-01

    The wetting behavior, interfacial reactions, and mechanical reliability of Sn-Ag-Cu solder on a plasma-coated printed circuit board (PCB) substrate were evaluated under multiple heat-treatments. Conventional organic solderability preservative (OSP) finished PCBs were used as a reference. The plasma process created a dense and highly cross-linked polymer coating on the Cu substrates. The plasma finished samples had higher wetting forces and shorter zero-cross times than those with OSP surface finish. The OSP sample was degraded after sequential multiple heat treatments and reflow processes, whereas the solderability of the plasma finished sample was retained after multiple heat treatments. After the soldering process, similar microstructures were observed at the interfaces of the two solder joints, where the development of intermetallic compounds was observed. From ball shear tests, it was found that the shear force for the plasma substrate was consistently higher than that for the OSP substrate. Deterioration of the OSP surface finish was observed after multiple heat treatments. Overall, the plasma surface finish was superior to the conventional OSP finish with respect to wettability and joint reliability, indicating that it is a suitable material for the fabrication of complex electronic devices.

  17. Electrical Resistance of the Solder Connections for the Consolidation of the LHC Main Interconnection Splices

    CERN Document Server

    Lutum, R; Scheuerlein, C

    2013-01-01

    For the consolidation of the LHC 13 kA main interconnection splices, shunts will be soldered onto each of the 10170 splices. The solder alloy selected for this purpose is Sn60Pb40. In this context the electrical resistance of shunt to busbar lap splices has been measured in the temperature range from RT to 20 K. A cryocooler set-up has been adapted such that a test current of 150 A could be injected for accurate resistance measurements in the low nΩ range. To study the influence of the solder bulk resistivity on the overall splice resistance, connections produced with Sn96Ag4 and Sn77.2In20Ag2.8 have been studied as well. The influence of the Sn60Pb40 solder resistance is negligible when measuring the splice resistance in a longitudinal configuration over a length of 6 cm. In a transverse measurement configuration the splice resistance is significantly influenced by the solder. The connections prepared with Sn77.2In20Ag2.8 show significantly higher resistance values, as expected from the relatively high sol...

  18. In situ X-ray observation and simulation of ratcheting-fatigue interactions in solder joints

    Science.gov (United States)

    Shi, Liting; Mei, Yunhui; Chen, Gang; Chen, Xu

    2017-01-01

    Reflow voids created by solder oxidation reduce the reliability of lap joints. In situ visualization of reflow voids in Sn-3Ag-0.5Cu (SAC305) lap-shear solder joints under cyclic stressing was realized by X-ray computed tomography (CT), while the ratcheting deformation of the solder joints was monitored by a non-contact displacement detecting system (NDDS). The results revealed that the shape evolution of reflow voids in solder joints, as characterized by the sphericity of the voids, can be divided into three stages: i.e., the initial stage with a sharp drop, a stable stage, and a rapidly declining stage. A new evolution law for describing the progress of sphericity was proposed, and was further introduced into a viscoplastic constitutive model based on the OW-AF nonlinear kinematic hardening rule. The damage-coupled OW-AF model yielded an accurate estimation of the whole-life ratcheting behavior of Sn-3Ag-0.5Cu (SAC305) lap-shear solder joints. [Figure not available: see fulltext.

  19. 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.

  20. The Role of Pd in Sn-Ag-Cu Solder Interconnect Mechanical Shock Performance

    Science.gov (United States)

    Lee, Tae-Kyu; Zhou, Bite; Bieler, Thomas R.; Tseng, Chien-Fu; Duh, Jeng-Gong

    2013-02-01

    The mechanical stability of solder joints with Pd added to Sn-Ag-Cu alloy with different aging conditions was investigated in a high- G level shock environment. A test vehicle with three different strain and shock level conditions in one board was used to identify the joint stability and failure modes. The results revealed that Pd provided stability at the package-side interface with an overall shock performance improvement of over 65% compared with the Sn-Ag-Cu alloy without Pd. A dependency on the pad structure was also identified. However, the strengthening mechanism was only observed in the non-solder mask defined (NSMD) pad design, whereas the solder mask defined (SMD) pad design boards showed no improvement in shock performance with Pd-added solders. The effects of Sn grain orientation on shock performance, interconnect stability, and crack propagation path with and without Pd are discussed. The SAC305 + Pd solder joints showed more grain refinements, recrystallization, and especially mechanical twin deformation during the shock test, which provides a partial explanation for the ability of SAC305 + Pd to absorb more shock-induced energy through active deformation compared with SAC305.

  1. Interfacial reactions of Sn-Ag-Cu solders modified by minor Zn alloying addition

    Science.gov (United States)

    Kang, Sung K.; Leonard, Donovan; Shih, Da-Yuan; Gignac, Lynne; Henderson, D. W.; Cho, Sungil; Yu, Jin

    2006-03-01

    The near-ternary eutectic Sn-Ag-Cu alloys have been identified as leading Pb-free solder candidates to replace Pb-bearing solders in microelectronic applications. However, recent investigations on the processing behavior and solder joints reliability assessment have revealed several potential reliability risk factors associated with the alloy system. The formation of large Ag3Sn plates in Sn-Ag-Cu joints, especially when solidified in a relatively slow cooling rate, is one issue of concern. The implications of large Ag3Sn plates on solder joint performance and several methods to control them have been discussed in previous studies. The minor Zn addition was found to be effective in reducing the amount of undercooling required for tin solidification and thereby to suppress the formation of large Ag3Sn plates. The Zn addition also caused the changes in the bulk microstructure as well as the interfacial reaction. In this paper, an in-depth characterization of the interfacial reaction of Zn-added Sn-Ag-Cu solders on Cu and Au/Ni(P) surface finishes is reported. The effects of a Zn addition on modification of the interfacial IMCs and their growth kinetics are also discussed.

  2. Wetting and Soldering Behavior of Eutectic Au-Ge Alloy on Cu and Ni Substrates

    Science.gov (United States)

    Leinenbach, C.; Valenza, F.; Giuranno, D.; Elsener, H. R.; Jin, S.; Novakovic, R.

    2011-07-01

    Au-Ge-based alloys are interesting as novel high-temperature lead-free solders because of their low melting point, good thermal and electrical conductivity, and high corrosion resistance. In the present work, the wetting and soldering behavior of the eutectic Au-28Ge (at.%) alloy on Cu and Ni substrates have been investigated. Good wetting on both substrates with final contact angles of 13° to 14° was observed. In addition, solder joints with bond shear strength of 30 MPa to 35 MPa could be produced under controlled conditions. Cu substrates exhibit pronounced dissolution into the Au-Ge filler metal. On Ni substrates, the NiGe intermetallic compound was formed at the filler/substrate interface, which prevents dissolution of Ni into the solder. Using thin filler metal foils (25 μm), complete consumption of Ge in the reaction at the Ni interface was observed, leading to the formation of an almost pure Au layer in the soldering zone.

  3. Metal ion release from silver soldering and laser welding caused by different types of mouthwash.

    Science.gov (United States)

    Erdogan, Ayse Tuygun; Nalbantgil, Didem; Ulkur, Feyza; Sahin, Fikrettin

    2015-07-01

    To compare metal ion release from samples welded with silver soldering and laser welding when immersed into mouthwashes with different ingredients. A total of 72 samples were prepared: 36 laser welded and 36 silver soldered. Four samples were chosen from each subgroup to study the morphologic changes on their surfaces via scanning electron microscopy (SEM). Each group was further divided into four groups where the samples were submerged into mouthwash containing sodium fluoride (NaF), mouthwash containing sodium fluoride + alcohol (NaF + alcohol), mouthwash containing chlorhexidine (CHX), or artificial saliva (AS) for 24 hours and removed thereafter. Subsequently, the metal ion release from the samples was measured with inductively coupled plasma mass spectrometry (ICP-MS). The metal ion release among the solutions and the welding methods were compared. The Kruskal-Wallis and analysis of variance (ANOVA) tests were used for the group comparisons, and post hoc Dunn multiple comparison test was utilized for the two group comparisons. The level of metal ion release from samples of silver soldering was higher than from samples of laser welding. Furthermore, greater amounts of nickel, chrome, and iron were released from silver soldering. With regard to the mouthwash solutions, the lowest amounts of metal ions were released in CHX, and the highest amounts of metal ions were released in NaF + alcohol. SEM images were in accord with these findings. The laser welding should be preferred over silver soldering. CHX can be recommended for patients who have welded appliances for orthodontic reasons.

  4. A Photodegradation Study of Three Common Paint and Plaster Biocides under monochromatic UV Light

    DEFF Research Database (Denmark)

    Minelgaite, Greta; Vollertsen, Jes; Nielsen, Asbjørn Haaning

    2014-01-01

    Photodegradation of the three common paint-and-plaster biocides (carbendazim, diuron and terbutryn) was investigated at controlled laboratory conditions. Samples prepared in two types of water (demineralized water and pond water) were subjected to 254 nm monochromatic UV light. Light intensity (W m......-2) in the experimental chamber was measured by a fiber optic spectrometer. The observed decline in biocide concentration was related with the light energy, accumulated during the time of degradation (kJ m-2), and 1st order photodegradation rate constants (m2 kJ-1) were determined. The obtained...... results demonstrated that diuron and terbutryn were readily degradable at the tested conditions, while carbendazim remained stable throughout the 28 – 34 hours of the experiments. Photodegradation rate constants of diuron and terbutryn were found to be slightly higher in demineralized water (0.0183 – 0...

  5. Archaeomagnetic investigation of oriented pre-Columbian lime-plasters from Teotihuacan, Mesoamerica

    Science.gov (United States)

    Soler-Arechalde, A. M.; Sánchez, F.; Rodriguez, M.; Caballero-Miranda, C.; Goguitchaishvili, A.; Urrutia-Fucugauchi, J.; Manzanilla, L.; Tarling, D. H.

    2006-10-01

    Results of an archaeomagnetic study of two excavation field seasons at the Xalla and Teopancazco residential areas of the ancient Prehispanic city of Teotihuacan, Central Mexico are reported. One-hundred and fifty three oriented samples of lime-plasters from the two archaeological sites were collected for the study. NRM directions are reasonably well grouped. Alternating field demagnetization shows single or two-component magnetizations. Rock magnetic measurements point to fine-grained titanomagnetites with pseudo-single domain behaviour. Characteristic site mean directions from both sites are correlated to the available palaeosecular variation curve for Mesoamerica. The mean directions obtained from Xalla site point to average dates of 550 AD±25 years that matches with the documented `Big Fire' of Teotihuacan (AD 575). Two consecutive construction levels at Teopancazco were estimated as AD 250-350 and AD 350-425 respectively.

  6. Effects of Ni-coated Carbon Nanotubes addition on the electromigration of Sn–Ag–Cu solder joints

    Energy Technology Data Exchange (ETDEWEB)

    Yang, Zhongbao; Zhou, Wei; Wu, Ping, E-mail: pingwu@tju.edu.cn

    2013-12-25

    Highlights: •The electromigration behaviors of the composite solder joints were investigated. •The presence of Ni altered the morphology of the IMC layer after reflow. •Carbon nanotube network was observed in solder matrix. •Current crowding occurred at the carbon nanotube networks. •The electromigration effect of composite solder joint was suppressed effectively. -- Abstract: The electromigration behaviors of line-type Cu/Sn–Ag–Cu/Cu interconnects with and without Ni-Coated multi-walled Carbon Nanotubes addition were investigated in this work. After soldering, the (Cu,Ni){sub 6}Sn{sub 5} intermetallic compounds formed at the solder/Cu interface. The electromigration analysis shows that the presence of Carbon Nanotubes can suppress the atomic diffusion in the solder induced by electromigration effectively. And finite element simulation indicates that the Carbon Nanotube networks can reduce the current density in the solder matrix, which results in the improvement of electromigration resistance of composite solders.

  7. Development of aluminum, manganese, and zinc-doped tin-silver-copper-X solders for electronic assembly

    Science.gov (United States)

    Boesenberg, Adam James

    The global electronic assembly community is striving for a robust replacement for leaded solders due to increased environmental regulations. A family of Pb-free solder alloys based on Sn-Ag-Cu (SAC) compositions has shown promise; but reliability issues in certain assembly and operating environments have arisen. Elemental (X) additions (Al, Mn, Zn) to SAC3595 were developed recently for better control of heterogeneous nucleation in solder joint solidification. Cu substrate solderability of these SAC+X alloys was investigated at concentrations between 0.01-0.25 wt. % using globule wetting balance tests due to concern about increased oxidation during reflow. Asymmetric four point bend (AFPB) tests were conducted on as-soldered and thermally aged specimens to investigate correlation between decreased shear strength and extended aging time; a common phenomenon seen in solder joints in service. Composition dependence of these X additions also was explored in simplified Cu joints by differential scanning calorimetry (DSC) and joint microstructure analysis to determine the coupling between undercooling and solidification morphology on single and multiple reflow cycles. Interesting observations by methods such as x-ray diffraction (XRD) and nano-indentation of SAC solder joints with aluminum elemental additions led to promising results and provided a possible solution to promoting heterogeneous nucleation and high reliability in these solder alloys.

  8. Compatibility of lead-free solders with lead containing surface finishes as a reliability issue in electronic assemblies

    Energy Technology Data Exchange (ETDEWEB)

    Vianco, P.; Rejent, J. [Sandia National Labs., Albuquerque, NM (United States); Artaki, I.; Ray, U.; Finley, D.; Jackson, A. [AT and T Bell Labs., Princeton, NJ (United States)

    1996-03-01

    Enhanced performance goals and environmental restrictions have heightened the consideration for use of alternative solders as replacements for the traditional tin-lead (Sn-Pb) eutectic and near-eutectic alloys. However, the implementation of non-Pb bearing surface finishes may lag behind solder alloy development. A study was performed which examined the effect(s) of Pb contamination on the performance of Sn-Ag-Bi and Sn-Ag-Cu-Sb lead-free solders by the controlled addition of 63Sn-37Pb solder at levels of 0.5 {minus} 8.0 wt.%. Thermal analysis and ring-in-plug shear strength studies were conducted on bulk solder properties. Circuit board prototype studies centered on the performance of 20I/O SOIC gull wing joints. Both alloys exhibited declines in their melting temperatures with greater Sn-Pb additions. The ring-in-plug shear strength of the Sn-Ag-Cu-Sb solder increased slightly with Sn-Pb levels while the Sn-Ag-Bi alloy experienced a strength loss. The mechanical behavior of the SOIC (Small Outline Integrated Circuit) Sn-Ag-Bi solder joints reproduced the strength levels were insensitive to 10,106 thermal cycles. The Sn-Ag-Cu-Sb solder showed a slight decrease in the gull wing joint strengths that was sensitive to the Pb content of the surface finish.

  9. Cleaning plaster surfaces with agar-agar gels: evaluation of the technique

    Directory of Open Access Journals (Sweden)

    Sonia Tortajada Hernando

    2013-07-01

    Full Text Available Abstract: Cleaning plaster surfaces represent a challenge for conservators It should only be performed following fully tested methods that guarantee the conservation of such fragile material. The goal of this work is to establishing a suitable cleaning method for this type of artworks from the tested concentrations and time of applications, using agar gels on plaster supports. Morphological, porosity and weight variations have been studied. Confocal and stereomicroscopy have been used as analytical techniques, as well as the measurement of water vapor permeability and weight have been taken on the samples. La limpieza de superficies de yeso-escayola con geles de agar-agar: evaluación de la técnica Resumen: La limpieza segura y eficiente de las superficies de yeso constituye un reto y una responsabilidad para el conservador-restaurador, y debe llevarse a cabo siguiendo métodos testados que garanticen su correcta conservación. La intención de este trabajo es determinar, a partir de las concentraciones y tiempos de aplicación ensayados, cuáles serían los parámetros óptimos para la ejecución de una limpieza eficaz e inocua empleando geles de agar-agar sobre soportes de yeso. Se han comprobado las posibles variaciones morfológicas de la superficie, las variaciones de la porosidad y del peso, así como la presencia de residuos, para lo cual se ha empleado la microscopía confocal, microscopía binocular, la medida de la permeabilidad al vapor de agua y la medida del peso de las muestras.

  10. Selection of the temperature of casting the bronzes to plaster moulds

    Directory of Open Access Journals (Sweden)

    B. Pisarek

    2009-07-01

    Full Text Available The results of the investigations of the process of solidification of the bronze CuSn5Zn5Pb5-C (B555 and CuSn10-C (B10 in the hot plaster mould show in the work. For four temperatures of casting: 1200 ° C, 1180 ° C, 1160 ° C and 1140 ° C was conducted the investi-gation: the size of contraction cavity, the fulfillment of the mould cavity formative the casts of test slats about the thickness: 4 mm, 0,8 mm and 0,5 mm. It was conducted the investigation the processes sets in the arrangement the cast-mould and X-ray analysis phase XRD of compound coming into being in indirect layer created among mould and cast in the result of the thermal decomposition of the anhy-drite. It results that the temperature 1140 ° C is the optimum temperature of casting the bronze to hot plaster mould from carried out investiga-tions. The minimum thickness of the wall of the cast from the bronze B555 is 0.5 mm, and from the bronze B10 0.8 mm.The realization of casts about thinner walls is made difficult because of giving off formed gases in the result of the thermal decomposition of the anhydrite. The products of the decomposition of the anhydrite react with elements steps in the chemical composition of studied bronzes, create in the arrangement the cast-mould the indirect layer folded from: sulphites, sulphides, oxides and clean metals (Pb or their compounds, especially Sn and Sb.

  11. Modeling Material Properties of Lead-Free Solder Alloys

    Science.gov (United States)

    Guo, Zhanli; Saunders, Nigel; Miodownik, Peter; Schillé, Jean-Philippe

    2008-01-01

    A full set of physical and thermophysical properties for lead-free solder (LFS) alloys have been calculated, including liquidus/solidus temperatures, fraction solid, density, coefficient of thermal expansion, thermal conductivity, Young’s modulus, viscosity, and liquid surface tension, all as a function of composition and temperature (extending into the liquid state). The results have been extensively validated against data available in the literature. A detailed comparison of the properties of two LFS alloys Sn-20In-2.8Ag and Sn-5.5Zn-4.5In-3.5Bi with Sn-37Pb has been made to show the utility and need for calculations that cover a wide range of properties, including the need to consider the effect of nonequilibrium cooling. The modeling of many of these properties follows well-established procedures previously used in JMatPro software for a range of structural alloys. This paper describes an additional procedure for the calculation of the liquid surface tension for multicomponent systems, based on the Butler equation. Future software developments are reviewed, including the addition of mechanical properties, but the present calculations can already make a useful contribution to the selection of appropriate new LFS alloys.

  12. Understanding the Influence of Copper Nanoparticles on Thermal Characteristics and Microstructural Development of a Tin-Silver Solder

    Science.gov (United States)

    Lin, D. C.; Srivatsan, T. S.; Wang, G.-X.; Kovacevic, R.

    2007-10-01

    This paper presents and discusses issues relevant to solidification of a chosen lead-free solder, the eutectic Sn-3.5%Ag, and its composite counterparts. Direct temperature recordings for the no-clean solder paste during the simulated reflow process revealed a significant amount of undercooling to occur prior to the initiation of solidification of the eutectic Sn-3.5%Ag solder, which is 6.5 °C, and for the composite counterparts, it is dependent on the percentage of copper nanopowder. Temperature recordings revealed the same temperature level of 221 °C for both melting (from solid to liquid) and final solidification (after recalescence) of the Sn-3.5%Ag solder. Addition of copper nanoparticles was observed to have no appreciable influence on melting temperature of the composite solder. However, it does influence solidification of the composite solder. The addition of 0.5 wt.% copper nanoparticles lowered the solidification temperature to 219.5 °C, while addition of 1.0 wt.% copper nanoparticles lowered the solidification temperature to 217.5 °C, which is close to the melting point of the ternary eutectic Sn-Ag-Cu solder alloy, Sn-3.7Ag-0.9Cu. This indicates the copper nanoparticles are completely dissolved in the eutectic Sn-3.5%Ag solder and precipitate as the Cu6Sn5, which reinforces the eutectic solder. Optical microscopy observations revealed the addition of 1.0 wt.% of copper nanoparticles to the Sn-3.5%Ag solder results in the formation and presence of the intermetallic compound Cu6Sn5. These particles are polygonal in morphology and dispersed randomly through the solder matrix. Addition of microsized copper particles cannot completely dissolve in the eutectic solder and projects a sunflower morphology with the solid copper particle surrounded by the Cu6Sn5 intermetallic compound coupled with residual porosity present in the solder sample. Microhardness measurements revealed the addition of copper nanopowder to the eutectic Sn-3.5%Ag solder resulted in

  13. An Investigation of TiO2 Addition on Microstructure Evolution of Sn-Cu-Ni Solder Paste Composite

    Directory of Open Access Journals (Sweden)

    Saud Norainiza

    2016-01-01

    Full Text Available In this research, varying fraction of titanium oxide (TiO2 reinforcement particles was successfully incorporated into Sn-Cu-Ni solder paste in an effort to study the influence of TiO2 addition on microstructure evolution of Sn-Cu-Ni solder paste composite. Sn-Cu-Ni solder paste composite was produced by mixing TiO2 particle with Sn-Cu-Ni solder paste. The microstructure analysis was carried out by Scanning Electron Microscopy-Energy dispersive X-ray (SEM-EDX. The addition TiO2 particle helps to refine the bulk solder microstructure and suppress the intermetallic compound (IMC formation at the interface as will be discussed further.

  14. Effects of rapid solidification on the microstructure and microhardness of a lead-free Sn-3.5Ag solder

    Institute of Scientific and Technical Information of China (English)

    SHEN Jun; LIU Yongchang; Han Yajing; GAO Houxiu

    2006-01-01

    A lead-free Sn-3.5Ag solder was prepared by rapid solidification technology. The high solidification rate, obtained by rapid cooling, promotes nucleation, and suppresses the growth of Ag3Sn intermetallic compounds (IMCs) in Ag-rich zone, yielding fine Ag3Sn nanoparticulates with spherical morphology in the matrix of the solder. The large amount of tough homogeneously-dispersed IMCs helps to improve the surface area per unit volume and obstructs the dislocation lines passing through the solder, which fits with the dispersion-strengthening theory. Hence, the rapidly-solidified Sn-3.5Ag solder exhibits a higher microhardness when compared with a slowly-solidified Sn-3.5Ag solder.

  15. WETTING OF COPPER BY LEAD-FREE Sn-Cu SOLDERS AND SHEAR STRENGTH OF Cu – Cu JOINTS

    Directory of Open Access Journals (Sweden)

    Pavol Šebo

    2009-04-01

    Full Text Available Developing and microstructure of lead-free Sn-Cu solders containing 3, 5 and 10 wt. % of copper in bulk as well as in ribbon form is presented. Wetting of copper substrate by these solders at the temperatures 300, 350 and 400°C in air (partially in N2+10H2 during 1800 s was studied by sessile drop method. Joints Cu – solder – Cu were prepared at 300°C and 1800 s in air as well as in gas mix and their shear strength was measured. The microstructure was studied by light and scanning electron microscopy (SEM equipped with energy dispersive X-ray analyzer and standard X-ray diffraction machine. Wetting angle decreases with increasing wetting temperature. Wetting angle increased for higher (10 wt. % amount of copper in solder. Shear strength of the joints decreases with increasing the copper concentration in solder.

  16. Alloying influences on low melt temperature SnZn and SnBi solder alloys for electronic interconnections

    Energy Technology Data Exchange (ETDEWEB)

    Ren, Guang [Stokes Laboratories, Bernal Institute, University of Limerick (Ireland); Department of Civil Engineering and Materials Science, University of Limerick (Ireland); Wilding, Ian J. [Henkel Ltd, Hemel Hempstead (United Kingdom); Collins, Maurice N., E-mail: Maurice.collins@ul.ie [Stokes Laboratories, Bernal Institute, University of Limerick (Ireland)

    2016-04-25

    Due to its commercial potential and the technological challenges associated with processing, low temperature soldering is a topic gaining widespread interest in both industry and academia in the application space of consumer and “throw away” electronics. This review focuses on the latest metallurgical alloys, tin zinc (Sn–Zn) and tin bismuth (Sn–Bi), for lower temperature processed electronic interconnections. The fundamentals of solder paste production and flux development for these highly surface active metallic powders are introduced. Intermetallic compounds that underpin low temperature solder joint production and reliability are discussed. The influence of alloying on these alloys is described in terms of critical microstructural changes, mechanical properties and reliability. The review concludes with an outlook for next generation electronic interconnect materials. - Highlights: • Review of the latest advances in Sn–Zn and Sn–Bi solder alloys. • Technological developments underpinning low temperature soldering. • Micro alloying influences on next generation interconnect materials.

  17. 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.

  18. Spreading Behavior and Evolution of IMCs During Reactive Wetting of SAC Solders on Smooth and Rough Copper Substrates

    Science.gov (United States)

    Satyanarayan; Prabhu, K. N.

    2013-08-01

    The effect of surface roughness of copper substrate on the reactive wetting of Sn-Ag-Cu solder alloys and morphology of intermetallic compounds (IMCs) was investigated. The spreading behavior of solder alloys on smooth and rough Cu substrates was categorized into capillary, diffusion/reaction, and contact angle stabilization zones. The increase in substrate surface roughness improved the wetting of solder alloys, being attributed to the presence of thick Cu3Sn IMC at the interface. The morphology of IMCs transformed from long needle shaped to short protruded type with an increase in the substrate surface roughness for the Sn-0.3Ag-0.7Cu and Sn-3Ag-0.5Cu solder alloys. However, for the Sn-2.5Ag-0.5Cu solder alloy the needle-shaped IMCs transformed to the completely scallop type with increase in the substrate surface roughness. The effect of Ag content on wetting behavior was not significant.

  19. A statistical mechanics model to predict electromigration induced damage and void growth in solder interconnects

    Science.gov (United States)

    Wang, Yuexing; Yao, Yao; Keer, Leon M.

    2017-02-01

    Electromigration is an irreversible mass diffusion process with damage accumulation in microelectronic materials and components under high current density. Based on experimental observations, cotton type voids dominate the electromigration damage accumulation prior to cracking in the solder interconnect. To clarify the damage evolution process corresponding to cotton type void growth, a statistical model is proposed to predict the stochastic characteristic of void growth under high current density. An analytical solution of the cotton type void volume growth over time is obtained. The synchronous electromigration induced damage accumulation is predicted by combining the statistical void growth and the entropy increment. The electromigration induced damage evolution in solder joints is developed and applied to verify the tensile strength deterioration of solder joints due to electromigration. The predictions agree well with the experimental results.

  20. Bosonisation and Soldering of Dual Symmetries in Two and Three Dimensions

    CERN Document Server

    Banerjee, R

    1997-01-01

    We develop a technique that solders the dual aspects of some symmetry following from the bosonisation of two distinct fermionic models, thereby leading to new results which cannot be otherwise obtained. Exploiting this technique, the two dimensional chiral determinants with opposite chirality are soldered to reproduce either the usual gauge invariant expression leading to the Schwinger model or, alternatively, the Thirring model. Likewise, two apparently independent three dimensional massive Thirring models with same coupling but opposite mass signatures, in the long wavelegth limit, combine by the process of bosonisation and soldering to yield an effective massive Maxwell theory. The current bosonisation formulas are given, both in the original independent formulation as well as the effective theory, and shown to yield consistent results for the correlation functions. Similar features also hold for quantum electrodynamics in three dimensions.