WorldWideScience

Sample records for flip chip packages

  1. Advanced flip chip packaging

    CERN Document Server

    Lai, Yi-Shao; Wong, CP

    2013-01-01

    Advanced Flip Chip Packaging presents past, present and future advances and trends in areas such as substrate technology, material development, and assembly processes. Flip chip packaging is now in widespread use in computing, communications, consumer and automotive electronics, and the demand for flip chip technology is continuing to grow in order to meet the need for products that offer better performance, are smaller, and are environmentally sustainable. This book also: Offers broad-ranging chapters with a focus on IC-package-system integration Provides viewpoints from leading industry executives and experts Details state-of-the-art achievements in process technologies and scientific research Presents a clear development history and touches on trends in the industry while also discussing up-to-date technology information Advanced Flip Chip Packaging is an ideal book for engineers, researchers, and graduate students interested in the field of flip chip packaging.

  2. Identifying Professional Competencies of the Flip-Chip Packaging Engineer in Taiwan

    Science.gov (United States)

    Guu, Y. H.; Lin, Kuen-Yi; Lee, Lung-Sheng

    2014-01-01

    This study employed a literature review, expert interviews, and a questionnaire survey to construct a set of two-tier competencies for a flip-chip packaging engineer. The fuzzy Delphi questionnaire was sent to 12 flip-chip engineering experts to identify professional competencies that a flip-chip packaging engineer must have. Four competencies,…

  3. The Numerical Analysis of Strain Behavior at Solder Joint and Interface of Flip Chip Package

    Institute of Scientific and Technical Information of China (English)

    S; C; Chen; Y; C; Lin

    2002-01-01

    The flip chip package is a kind of advanced electri ca l packages. Due to the requirement of miniaturization, lower weight, higher dens ity and higher performance in the advanced electric package, it is expected that flip chip package will soon be a mainstream technology. The silicon chip is dir ectly connected to printing circuit substrate by SnPb solder joints. Also, the u nderfill, a composite of polymer and silica particles, is filled in the gap betw een the chip and substrate around the solder joint...

  4. Molded underfill (MUF) encapsulation for flip-chip package: A numerical investigation

    Science.gov (United States)

    Azmi, M. A.; Abdullah, M. K.; Abdullah, M. Z.; Ariff, Z. M.; Saad, Abdullah Aziz; Hamid, M. F.; Ismail, M. A.

    2017-07-01

    This paper presents the numerical simulation of epoxy molding compound (EMC) filling in multi flip-chip packages during encapsulation process. The empty and a group flip chip packages were considered in the mold cavity in order to study the flow profile of the EMC. SOLIDWORKS software was used for three-dimensional modeling and it was incorporated into fluid analysis software namely as ANSYS FLUENT. The volume of fluid (VOF) technique was used for capturing the flow front profiles and Power Law model was applied for its rheology model. The numerical result are compared and discussed with previous experimental and it was shown a good conformity for model validation. The prediction of flow front was observed and analyzed at different filling time. The possibility and visual of void formation in the package is captured and the number of flip-chip is one factor that contributed to the void formation.

  5. A two-dimensional simulation model for the molded underfill process in flip chip packaging

    Energy Technology Data Exchange (ETDEWEB)

    Guo, Xue Ru; Young, Wen Bin [National Cheng Kung University, Tainan (China)

    2015-07-15

    The flip chip process involves the deposition of solder bumps on the chip surface and their subsequent direct attachment and connection to a substrate. Underfilling traditional flip chip packaging is typically performed following a two-step approach. The first step uses capillary force to fill the gap between the chip and the substrate, and the second step uses epoxy molding compound (EMC) to overmold the package. Unlike traditional flip chip packaging, the molded underfill (MUF) concept uses a single-step approach to simultaneously achieve both underfill and overmold. MUF is a simpler and faster process. In this study, a 2D numerical model is developed to simulate the front movement of EMC flow and the void formation for different geometric parameters. The 2D model simplifies the procedures of geometric modeling and reduces the modeling time for the MUF simulation. Experiments are conducted to verify the prediction results of the model. The effect on void formation for different geometric parameters is investigated using a 2D model.

  6. MICROELECTRONICS: Flip the Chip.

    Science.gov (United States)

    Wong, C P; Luo, S; Zhang, Z

    2000-12-22

    As integrated circuit fabrication advances rapidly and the market for faster, lighter, smaller, yet less expensive electronic products accelerates, electronic packaging faces its own challenges. In this Perspective, Wong, Luo, and Zhang describe recent advances in flip chip packaging. This technology has many advantages over the conventional wire bonding technology and offers the possibility of low-cost electronic assembly for modern electronic products.

  7. Effect of aluminum trace dimension on electro-migration failure in flip-chip package

    Science.gov (United States)

    Liu, Peisheng; Fan, Guangming; Liu, Yahong; Yang, Longlong; Miao, Xiaoyong

    2017-03-01

    A 3D model of flip-chip package is established and thermal-electrical coupling is analyzed. The effect of the width of Aluminum (Al) trace on electro-migration mechanism is also studied. Reducing rates of the hot-spot temperature, the max Joule heating, the max temperature gradient and the max current density are defined to research the effects of the Al trace thickness and the UBM thickness on electro-migration.

  8. Selective low temperature microcap packaging technique through flip chip and wafer level alignment

    Science.gov (United States)

    Pan, C. T.

    2004-04-01

    In this study, a new technique of selective microcap bonding for packaging 3-D MEMS (Micro Electro Mechanical Systems) devices is presented. Microcap bonding on a selected area of the host wafer was successfully demonstrated through flip chip and wafer level alignment. A passivation treatment was developed to separate the microcap from the carrier wafer. A thick metal nickel (Ni) microcap was fabricated by an electroplating process. Its stiffness is superior to that of thin film poly-silicon made by the surface micromachining technique. For the selective microcap packaging process, photo definable materials served as the intermediate adhesive layer between the host wafer and the metal microcap on the carrier wafer. Several types of photo definable material used as the adhesive layer were tested and characterized for bonding strength. The experimental result shows that excellent bonding strength at low bonding temperature can be achieved.

  9. Application of Underfill for Flip-Chip Package Using Ultrasonic Bonding

    Science.gov (United States)

    Noh, Bo-In; Koo, Ja-Myeong; Jo, Jung-Lae; Jung, Seung-Boo

    2008-05-01

    In this study, the reliability of flip-chip (FC) packages with various underfills using ultrasonic bonding was evaluated in temperature and humidity (TH) tests. Fatigue cracks began at the interface between the Au bumps and glass substrate and then propagated through the interface with increasing dwell time in the TH test. The initial electrical resistance of Au bumps with lower viscosity underfill was lower than that of Au bumps with higher viscosity underfill. Entrapped underfill between the Au bumps and glass substrate or void formation between the Au bumps in FC packages was caused by high viscosity of the underfill. As the dwell time of the TH test increased, the electrical resistance of the FC packages increased. The fatigue life of an FC package with underfill that has a higher glass transition temperature (Tg) and lower coefficient of thermal expansion (CTE) value was higher than that of an FC package with underfill with lower Tg and a higher CTE value. Therefore, the properties of underfill affect the fatigue life of FC packages with underfill using ultrasonic bonding.

  10. Laser-induced forward transfer for flip-chip packaging of single dies.

    Science.gov (United States)

    Kaur, Kamal S; Van Steenberge, Geert

    2015-03-20

    Flip-chip (FC) packaging is a key technology for realizing high performance, ultra-miniaturized and high-density circuits in the micro-electronics industry. In this technique the chip and/or the substrate is bumped and the two are bonded via these conductive bumps. Many bumping techniques have been developed and intensively investigated since the introduction of the FC technology in 1960(1) such as stencil printing, stud bumping, evaporation and electroless/electroplating2. Despite the progress that these methods have made they all suffer from one or more than one drawbacks that need to be addressed such as cost, complex processing steps, high processing temperatures, manufacturing time and most importantly the lack of flexibility. In this paper, we demonstrate a simple and cost-effective laser-based bump forming technique known as Laser-induced Forward Transfer (LIFT)3. Using the LIFT technique a wide range of bump materials can be printed in a single-step with great flexibility, high speed and accuracy at RT. In addition, LIFT enables the bumping and bonding down to chip-scale, which is critical for fabricating ultra-miniature circuitry.

  11. Numerical Analysis of Warpage Induced by Thermo-Compression Bonding Process of Cu Pillar Bump Flip Chip Package

    Energy Technology Data Exchange (ETDEWEB)

    Kwon, Oh Young; Jung, Hoon Sun; Lee, Jung Hoon; Choa, Sung-Hoon [Seoul Nat’l Univ. of Science and Technology, Seoul (Korea, Republic of)

    2017-06-15

    In flip chip technology, the conventional solder bump has been replaced with a copper (Cu) pillar bump owing to its higher input/output (I/O) density, finer pitch, and higher reliability. However, Cu pillar bump technology faces several issues, such as interconnect shorting and higher low-k stress due to stiffer Cu pillar structure when the conventional reflow process is used. Therefore, the thermal compression bonding (TCB) process has been adopted in the flip chip attachment process in order to reduce the package warpage and stress. In this study, we investigated the package warpage induced during the TCB process using a numerical analysis. The warpage of the TCB process was compared with that of the reflow process.

  12. 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...

  13. Reliability of an ultra-fine-pitch COF flip-chip package using non-conductive paste

    Science.gov (United States)

    Kim, Hae-Yeon; Min, Kyung-Eun; Lee, Jun-Sik; Lee, So-Jeong; Lee, Sung-Soo; Kim, Jun-Ki

    2016-01-01

    Ultra-fine-pitch chip-on-film (COF) packages such as display-drive-integrated circuit (DDI) modules are manufactured through an underfill process following Au-to-Sn thermo-compression bonding. As the interconnection pitch becomes finer and is reduced to less than 25 um, however, an alternative flip-chip technology, such as non-conductive paste (NCP) bonding, is needed in place of the capillary underfill process. In this study, new NCP formulations are investigated to achieve rapid curing at a temperature high enough to form a metallic bond between the bump and the pad. An appropriate curing agent was determined through a dielectric analysis (DEA). COF samples were prepared with a DDI chip 11,772 × 924 um in size and with a 38 um-thick polyimide flexible printed circuit by both NCP bonding and thermo-compressionunderfill processes. Pressure cooker tests lasting as long as 192 h revealed that the reliability of the NCP sample against high temperatures and high humidity levels exceeded somewhat that of the underfill sample. In thermal cycling test up to 500 cycles, however, the reliability of the NCP sample was inferior to that of the underfill sample. It was considered that unbonded faults and NCP trapping at the bump-to-pad joint were responsible for the premature failure of the NCP sample under a thermal cycling condition. [Figure not available: see fulltext.

  14. An Introduction to Flip-Chip Packaging Technology%倒装芯片封装技术概论

    Institute of Scientific and Technical Information of China (English)

    张文杰; 朱朋莉; 赵涛; 孙蓉; 汪正平

    2014-01-01

    As the high density package is moving towards miniaturization, high I/O density, better thermal and high reliable system, the conventional wire bonding technology can not satisfy the product need already. The advanced lfip chip technology is highly expected due to its high area array I/O interconnection, short signal path, high thermal dissipation, high electrical and thermal performance. In order to enhance the reliability of a flip-chip on organic board package, underifll is used between the chip and the substrate to redistribute the thermo-mechanical stress created by the coefifcient of thermal expansion (CTE) mismatch between the silicon chip and organic substrate. However, the conventional underifll relies on the capillary lfow of the underifll material and has many disadvantages. In order to overcome these disadvantages, no-lfow underifll has been invented to improve the lfip-chip underifll process. This paper reviews the development of lfip-chip technology and expounds the behavior of lfow and no-lfow underifll.%高密度电子封装正朝着小型化、高I/O 密度、更好的散热性和高的可靠性方向发展,传统引线键合技术已经无法满足要求。先进的倒装芯片封装技术由于具有较高的单位面积内 I/O 数量、短的信号路径、高的散热性、良好的电学和热力学性能,在电子封装中被广泛关注。底部填充胶被填充在芯片与基板之间的间隙,来降低芯片与基板热膨胀系数不匹配产生的应力,提高封装的稳定性。然而,流动底部填充胶依赖于胶的毛细作用进行填充,存在很多缺点。为了克服这些缺点,出现了非流动底部填充胶,以改善倒装芯片底部填充工艺。文章回顾了倒装芯片封装技术的发展,阐述了流动和非流动底部填充胶的施胶方式和性质。

  15. New IC package, assembly technique by means of a "blind" alignment "flip-chip" method and assembling facilities

    Institute of Scientific and Technical Information of China (English)

    Vladimir V. Novikov

    2004-01-01

    @@ In spite of a long period of the development ofmicroelectronic components base, the problem of the creation of IC package design, providing minimal area losses in contrast with area of a chip, remains unsolved [1]Area losses can be described by the parameter P,which is equal to the ratio between the package area in plan and the chip area:

  16. Advanced Flip Chips in Extreme Temperature Environments

    Science.gov (United States)

    Ramesham, Rajeshuni

    2010-01-01

    material and the silicon die or chip, and also the underfill materials. Advanced packaging interconnects technology such as flip-chip interconnect test boards have been subjected to various extreme temperature ranges that cover military specifications and extreme Mars and asteroid environments. The eventual goal of each process step and the entire process is to produce components with 100 percent interconnect and satisfy the reliability requirements. Underfill materials, in general, may possibly meet demanding end use requirements such as low warpage, low stress, fine pitch, high reliability, and high adhesion.

  17. Developments of optimum flip-chip bonding process

    Science.gov (United States)

    Jang, Dong H.; Kang, Sa Y.; Lee, Y. M.; Oh, S. Y.

    1997-08-01

    Flip-chip soldering is the critical technology for solving the current issues of electronic packaging industries that require the high I/O's. In order to increase the manufacturing ability of flip-chip technology, however, yield and reliability tissues should overcome. In this study, optimum flip-chip bonding process has been developed by using the test chips that had the electroplated solder bumps. Test chips are composed of three different types that are i) peripheral array pad chip, ii) peripheral array pad chip, and iii) area array pad chip. Each test chip has the daisy chain to consider the effect of reliability test. The electrical resistance was measured before and after reliability test. Based on these measurement, failure mode resulted from the moisture absorption was studied using scanning acoustic microscope. To achieve an optimum reflow profile of solder bump, correct temperature profile was set up with respect to the resin base flux. Different bonding forces were tested. Four underfill encapsulants were evaluated for minimum voids that caused the severe defects after reliability test. Also, the gap heights were measured with respect to applied bonding force after underfill was performed. Results from the moisture absorption and thermal cycling were discussed for flip-chip bonding on BT-resin substrates. The test vehicles using flip-chip technology have passed moisture preconditioning and temperature cycling tests.

  18. Nondestructive diagnosis of flip chips based on vibration analysis using PCA-RBF

    Science.gov (United States)

    Su, Lei; Shi, Tielin; Liu, Zhiping; Zhou, Hongdi; Du, Li; Liao, Guanglan

    2017-02-01

    Flip chip technology combined with solder bump interconnection has been widely applied in IC package. The solder bumps are sandwiched between dies and substrates, leading to conventional techniques being difficult to diagnose the flip chips. Meanwhile, these conventional diagnosis methods are usually performed by human visual judgment. The human eye-fatigue can easily cause fault detection. Thus, it is difficult and crucial to detect the defects of flip chips automatically. In this paper, a nondestructive diagnosis system based on vibration analysis is proposed. The flip chip is excited by air-coupled ultrasounds and raw vibration signals are measured by a laser scanning vibrometer. Forty-two features are extracted for analysis, including ten time domain features, sixteen frequency domain features and sixteen wavelet packet energy features. Principal component analysis is used for feature reduction. Radial basis function neural network is adopted for classification and recognition. Flip chips in three states (good flip chips, flip chips with missing solder bumps and flip chips with open solder bumps) are utilized to validate the proposed method. The results demonstrate that this method is effective for defect inspection in flip chip package.

  19. 一种数字微镜器件的倒装封装设计%Design of the Flip-Chip Package for Digital Micromirror Devices

    Institute of Scientific and Technical Information of China (English)

    李中楠; 王淑仙

    2012-01-01

    数字微镜器件是由MEMS工艺制成的数字式光反射开关阵列组成,其I/O管脚工作频率高达800 MHz.针对数字微镜器件的对光电两方面性能的严格要求,设计了一种数字微镜器件的封装结构.首先选择倒装封装技术来减小寄生参数,提高器件响应速度;其次优化了板层结构,采用玻璃基底和遮光层来满足光学要求;最后通过对信号完整性和电源完整性问题的仿真设计,满足了电学性能要求,完善了封装基板设计流程.对制作出的微镜器件封装进行测试,在800 MHz的数据频率下,眼图结果与仿真结果较为吻合,降低了封装对信号完整性的影响,达到封装设计要求的指标.%Digital micromirror device is composed of arrays of fast reflective digital light switches which are made by the MEMS fabrication technology, and the highest frequency of I/O pins can be up to 800 MHz. According to the characteristics of this device, a special package design for the advanced digital micromirror device was proposed. This package used the flip-chip technology for smaller parasitic parameter and higher speed. An optimized package structure which used the glass substrate and light shield was adopted to satisfy the optical requests. An appropriate simulation method for signal integrity and power integrity was adopted to satisfy the electrical requests and improved the substrate design flow. The test for the device which has been produced indicates that the eyediagram tally well with the simulation waveform when the frequency of I/O pins is 800 MHz. It reduces the influence of the package on signal integrity problems and meets the requirement of this design.

  20. Electroplated solder alloys for flip chip interconnections

    Science.gov (United States)

    Annala, P.; Kaitila, J.; Salonen, J.

    1997-01-01

    Flip chip mounting of bare dice is gaining widespread use in microelectronics packaging. The main drivers for this technology are high packaging density, improved performance at high frequency, low parasitic effects and potentially high reliability and low cost. Many companies have made significant efforts to develop a technology for bump processing, bare die testing and underfill encapsulation to gain the benefit of all potential advantages. We have focussed on low cost bumping of fully processed silicon wafers to develop a flexible scheme for various reflow requirements. The bumping process is based on galvanic plating from an alloy solution or, alternatively, from several elemental plating baths. Sputtered Mo/Cu or Cr/Cu is used as a wettable base for electroplating. Excess base metal is removed by using the bumps as an etching mask. Variation of the alloy composition or the layer structure, allows the adjustment of the bump reflow temperature for the specific requirements of the assembly. Using binary tin-lead and ternary tin-lead-bismuth alloys, reflow temperatures from 100 °C (bismuth rich alloys) to above 300 °C (lead rich alloys) can be covered. The influence of the plating current density on the final alloy composition has been established by ion beam analysis of the plated layers and a series of reflow experiments. To control the plating uniformity and the alloy composition, a new cup plating system has been built with a random flow pattern and continuous adjustment of the current density. A well-controlled reflow of the bumps has been achieved in hot glycerol up to the eutectic point of tin-lead alloys. For high temperature alloys, high molecular weight organic liquids have been used. A tensile pull strength of 20 g per bump and resistance of 5 mΩ per bump have been measured for typical eutectic tin-lead bumps of 100 μm in diameter.

  1. Flip-chip light emitting diode with resonant optical microcavity

    Science.gov (United States)

    Gee, James M.; Bogart, Katherine H.A.; Fischer, Arthur J.

    2005-11-29

    A flip-chip light emitting diode with enhanced efficiency. The device structure employs a microcavity structure in a flip-chip configuration. The microcavity enhances the light emission in vertical modes, which are readily extracted from the device. Most of the rest of the light is emitted into waveguided lateral modes. Flip-chip configuration is advantageous for light emitting diodes (LEDs) grown on dielectric substrates (e.g., gallium nitride LEDs grown on sapphire substrates) in general due to better thermal dissipation and lower series resistance. Flip-chip configuration is advantageous for microcavity LEDs in particular because (a) one of the reflectors is a high-reflectivity metal ohmic contact that is already part of the flip-chip configuration, and (b) current conduction is only required through a single distributed Bragg reflector. Some of the waveguided lateral modes can also be extracted with angled sidewalls used for the interdigitated contacts in the flip-chip configuration.

  2. Amdahl 470 Chip Package

    CERN Multimedia

    1975-01-01

    In the late 70s the larger IBM computers were water cooled. Amdahl, an IBM competitor, invented an air cooling technology for it's computers. His company worked hard, developing a computer that was faster and less expensive than the IBM System/360 mainframe computer systems. This object contains an actual Amdahl series 470 computer logic chip with an air cooling device mounted on top. The package leads and cooling tower are gold-plated.

  3. Flip chip bumping technology-Status and update

    Energy Technology Data Exchange (ETDEWEB)

    Juergen Wolf, M. [Fraunhofer IZM, Gustav-Meyer-Allee 25, 13355 Berlin (Germany)]. E-mail: juergen.Wolf@izm.fraunhofer.de; Engelmann, Gunter [Fraunhofer IZM, Gustav-Meyer-Allee 25, 13355 Berlin (Germany); Dietrich, Lothar [Fraunhofer IZM, Gustav-Meyer-Allee 25, 13355 Berlin (Germany); Reichl, Herbert [Fraunhofer IZM, Gustav-Meyer-Allee 25, 13355 Berlin (Germany)

    2006-09-01

    Flip chip technology is a key driver for new complex system architectures and high-density packaging, e.g. sensor or pixel devices. Bumped wafers/dice as key elements become very important in terms of general availability at low cost, high yield and quality level. Today, different materials, e.g. Au, Ni, AuSn, SnAg, SnAgCu, SnCu, etc., are used for flip chip interconnects and different bumping approaches are available. Electroplating is the technology of choice for high-yield wafer bumping for small bump sizes and pitches. Lead-free solder bumps require an increase in knowledge in the field of under bump metallization (UBM) and the interaction of bump and substrate metallization, the formation and growth of intermetallic compounds (IMCs) during liquid- and solid-phase reactions. Results of a new bi-layer UBM of Ni-Cu which is especially designed for small-sized lead-free solder bumps will be discussed.

  4. Polymer Flip Chips with Extreme Temperature Stability in Space Project

    Data.gov (United States)

    National Aeronautics and Space Administration — The objective of the proposed SBIR Phase I program is to develop highly thermally and electrically conductive nanocomposites for space-based flip chips for...

  5. Experiences in flip chip production of radiation detectors

    Science.gov (United States)

    Savolainen-Pulli, Satu; Salonen, Jaakko; Salmi, Jorma; Vähänen, Sami

    2006-09-01

    Modern imaging devices often require heterogeneous integration of different materials and technologies. Because of yield considerations, material availability, and various technological limitations, an extremely fine pitch is necessary to realize high-resolution images. Thus, there is a need for a hybridization technology that is able to join together readout amplifiers and pixel detectors at a very fine pitch. This paper describes radiation detector flip chip production at VTT. Our flip chip technology utilizes 25-μm diameter tin-lead solder bumps at a 50-μm pitch and is based on flux-free bonding. When preprocessed wafers are used, as is the case here, the total yield is defined only partly by the flip chip process. Wafer preprocessing done by a third-party silicon foundry and the flip chip process create different process defects. Wafer-level yield maps (based on probing) provided by the customer are used to select good readout chips for assembly. Wafer probing is often done outside of a real clean room environment, resulting in particle contamination and/or scratches on the wafers. Factors affecting the total yield of flip chip bonded detectors are discussed, and some yield numbers of the process are given. Ways to improve yield are considered, and finally guidelines for process planning and device design with respect to yield optimization are given.

  6. Experiences in flip chip production of radiation detectors

    Energy Technology Data Exchange (ETDEWEB)

    Savolainen-Pulli, Satu [VTT, MEMS- and Micropackaging, P.O. Box 1000, Tietotie 3, Espoo, FI-02044 VTT (Finland)]. E-mail: satu.savolainen-pulli@vtt.fi; Salonen, Jaakko [VTT, MEMS- and Micropackaging, P.O. Box 1000, Tietotie 3, Espoo, FI-02044 VTT (Finland); Salmi, Jorma [VTT, MEMS- and Micropackaging, P.O. Box 1000, Tietotie 3, Espoo, FI-02044 VTT (Finland); Vaehaenen, Sami [VTT, MEMS- and Micropackaging, P.O. Box 1000, Tietotie 3, Espoo, FI-02044 VTT (Finland)

    2006-09-01

    Modern imaging devices often require heterogeneous integration of different materials and technologies. Because of yield considerations, material availability, and various technological limitations, an extremely fine pitch is necessary to realize high-resolution images. Thus, there is a need for a hybridization technology that is able to join together readout amplifiers and pixel detectors at a very fine pitch. This paper describes radiation detector flip chip production at VTT. Our flip chip technology utilizes 25-{mu}m diameter tin-lead solder bumps at a 50-{mu}m pitch and is based on flux-free bonding. When preprocessed wafers are used, as is the case here, the total yield is defined only partly by the flip chip process. Wafer preprocessing done by a third-party silicon foundry and the flip chip process create different process defects. Wafer-level yield maps (based on probing) provided by the customer are used to select good readout chips for assembly. Wafer probing is often done outside of a real clean room environment, resulting in particle contamination and/or scratches on the wafers. Factors affecting the total yield of flip chip bonded detectors are discussed, and some yield numbers of the process are given. Ways to improve yield are considered, and finally guidelines for process planning and device design with respect to yield optimization are given.

  7. Physics of Failure Analysis of Xilinx Flip Chip CCGA Packages: Effects of Mission Environments on Properties of LP2 Underfill and ATI Lid Adhesive Materials

    Science.gov (United States)

    Suh, Jong-ook

    2013-01-01

    The Xilinx Virtex 4QV and 5QV (V4 and V5) are next-generation field-programmable gate arrays (FPGAs) for space applications. However, there have been concerns within the space community regarding the non-hermeticity of V4/V5 packages; polymeric materials such as the underfill and lid adhesive will be directly exposed to the space environment. In this study, reliability concerns associated with the non-hermeticity of V4/V5 packages were investigated by studying properties and behavior of the underfill and the lid adhesvie materials used in V4/V5 packages.

  8. Underfill process development for lead free flip chip assembly

    Science.gov (United States)

    Chaware, Raghunandan

    Underfills are used to enhance the long-term reliability of the flip-chip solder joints. More specifically, the function of the underfill is to couple the chip to the substrate, wherein the shear stresses experienced by the solder joints are converted to bending stresses. The underfill flows under the die due to the influence of strong capillary forces. The flow of the underfill under the chip depends on various factors such as the viscosity of the underfill, contact angle, surface tension, temperature, underfill gap, substrate design, bump pattern, bump density, and size of the chip. The flow of underfill is also influenced by the cleanliness of the substrate, the cleanliness of the underside of the chip, and the flux residues. The interaction between the underfill and the substrate affects not only gap filling, but also the filleting of the underfill. Similarly, the underfill-flux interaction directly affects the quality of underfilling and the reliability of the flip chip assembly. In the case of lead free flip chip assembly, the major concerns vis-a-vis process development for a large chip with a small bump pitch (less than 190 mum) include lower throughput, voiding under the chip, and critical reliability performance. The principal objective of this research endeavor was to investigate the fundamental issues that relate to the process and reliability aspects of underfilling of lead free flip chip assemblies. In order to develop a robust underfilling process, the effect of different process parameters and their interaction with the material properties were studied. In order to improve the compatibility between the underfill and the flux, a new epoxy flux that was compatible with the lead free assembly process was developed. The performance of the epoxy was also compared with the performance of various rosin based fluxes. This study also helped in identifying the critical parameters that can affect the assembly yields. This research endeavor successfully

  9. Simulation des Underfill-Prozesses bei Flip Chip-Anwendungen

    OpenAIRE

    Häußermann, Tanja

    2009-01-01

    Flip Chips sind elektronische Bauteile, die über leitfähige Höcker, so genannte Bumps, mit der aktiven Seite nach unten direkt auf dem Träger kontaktiert werden. Am häufigsten werden die Chips mit Hilfe von Lotbumps mit organischen Substraten verbunden. Nach dem Löten wird der Spalt zwischen Chip und Substrat komplett mit einem nicht leitfähigen Klebstoff, dem so genannten Underfiller, aufgefüllt. Der flüssige Underfiller wird entlang einer oder mehrerer Chipkanten appliziert, durch Kapillarw...

  10. Flexible packaging of solid-state integrated circuit chips with elastomeric microfluidics

    OpenAIRE

    Bowei Zhang; Quan Dong; Korman, Can E.; Zhenyu Li; Zaghloul, Mona E.

    2013-01-01

    A flexible technology is proposed to integrate smart electronics and microfluidics all embedded in an elastomer package. The microfluidic channels are used to deliver both liquid samples and liquid metals to the integrated circuits (ICs). The liquid metals are used to realize electrical interconnects to the IC chip. This avoids the traditional IC packaging challenges, such as wire-bonding and flip-chip bonding, which are not compatible with current microfluidic technologies. As a demonstratio...

  11. Seamless integration of CMOS and microfluidics using flip chip bonding

    Science.gov (United States)

    Welch, David; Blain Christen, Jennifer

    2013-03-01

    We demonstrate the microassembly of PDMS (polydimethylsiloxane) microfluidics with integrated circuits made in complementary metal-oxide-semiconductor (CMOS) processes. CMOS-sized chips are flip chip bonded to a flexible polyimide printed circuit board (PCB) with commercially available solder paste patterned using a SU-8 epoxy. The average resistance of each flip chip bond is negligible and all connections are electrically isolated. PDMS is attached to the flexible polyimide PCB using a combination of oxygen plasma treatment and chemical bonding with 3-aminopropyltriethoxysilane. The total device has a burst pressure of 175 kPA which is limited by the strength of the flip chip attachment. This technique allows the sensor area of the die to act as the bottom of the microfluidic channel. The SU-8 provides a barrier between the pad ring (electrical interface) and the fluids; post-processing is not required on the CMOS die. This assembly method shows great promise for developing analytic systems which combine the strengths of microelectronics and microfluidics into one device.

  12. A numerical study of void nucleation and growth in a flip chip assembly process

    Science.gov (United States)

    Lee, Sangil; Zhou, Hao Min; Baldwin, Daniel F.

    2010-09-01

    In this study, we develop mathematical models and numerical simulations of void nucleation and growth induced by the chemical reaction in the flip chip package assembly process using a no-flow underfill. During the thermal assembly process, the underfill chemically reacts to the oxidation of solders I/O on the chip, achieving interconnection between chip and substrate. The chemical reaction causes a large number of voids in the thermal reflow process. The voids have been considered as a critical defect, reducing the life of the thermal reliability. This study investigates the mechanism of void nucleation and growth based on classical bubble nucleation theory and bubble dynamics, respectively. This knowledge can provide a theoretical foundation to achieve a void-free assembly process and high reliability performance.

  13. Optimization of Indium Bump Morphology for Improved Flip Chip Devices

    Science.gov (United States)

    Jones, Todd J.; Nikzad, Shouleh; Cunningham, Thomas J.; Blazejewski, Edward; Dickie, Matthew R.; Hoenk, Michael E.; Greer, Harold F.

    2011-01-01

    Flip-chip hybridization, also known as bump bonding, is a packaging technique for microelectronic devices that directly connects an active element or detector to a substrate readout face-to-face, eliminating the need for wire bonding. In order to make conductive links between the two parts, a solder material is used between the bond pads on each side. Solder bumps, composed of indium metal, are typically deposited by thermal evaporation onto the active regions of the device and substrate. While indium bump technology has been a part of the electronic interconnect process field for many years and has been extensively employed in the infrared imager industry, obtaining a reliable, high-yield process for high-density patterns of bumps can be quite difficult. Under the right conditions, a moderate hydrogen plasma exposure can raise the temperature of the indium bump to the point where it can flow. This flow can result in a desirable shape where indium will efficiently wet the metal contact pad to provide good electrical contact to the underlying readout or imager circuit. However, it is extremely important to carefully control this process as the intensity of the hydrogen plasma treatment dramatically affects the indium bump morphology. To ensure the fine-tuning of this reflow process, it is necessary to have realtime feedback on the status of the bumps. With an appropriately placed viewport in a plasma chamber, one can image a small field (a square of approximately 5 millimeters on each side) of the bumps (10-20 microns in size) during the hydrogen plasma reflow process. By monitoring the shape of the bumps in real time using a video camera mounted to a telescoping 12 magnifying zoom lens and associated optical elements, an engineer can precisely determine when the reflow of the bumps has occurred, and can shut off the plasma before evaporation or de-wetting takes place.

  14. A Novel Magnetic Bead-based Biosensor Using Flip Chip Bonding Techniques

    Institute of Scientific and Technical Information of China (English)

    Bin Wang; Xiang Chen; Qinghui Jin; Jianlong Zhao; Yuansen Xu

    2006-01-01

    Based on flip-chip packaging, a novel approach towards integrated magnetic bio-separator was designed. The magnetic field and the force on the bead were simulated and analyzed, leading to the optimization of the fabrication parameters of the micro-magnetic unit. The planar coil as an electromagnet was fabricated through electroplating on a single seed layer.The PDMS microfluidic channel was bonded on the inverse side after Si etching. The results presented in this paper provide a novel design and fabrication to approach a microfluidic bio-separation system with magnetic beads.

  15. Flip chip assembly of thinned chips for hybrid pixel detector applications

    CERN Document Server

    Fritzsch, T; Woehrmann, M; Rothermund, M; Huegging, F; Ehrmann, O; Oppermann, H; Lang, K.D

    2014-01-01

    There is a steady trend to ultra-thin microelectronic devices. Especially for future particle detector systems a reduced readout chip thickness is required to limit the loss of tracking precision due to scattering. The reduction of silicon thickness is performed at wafer level in a two-step thinning process. To minimize the risk of wafer breakage the thinned wafer needs to be handled by a carrier during the whole process chain of wafer bumping. Another key process is the flip chip assembly of thinned readout chips onto thin sensor tiles. Besides the prevention of silicon breakage the minimization of chip warpage is one additional task for a high yield and reliable flip chip process. A new technology using glass carrier wafer will be described in detail. The main advantage of this technology is the combination of a carrier support during wafer processing and the chip support during flip chip assembly. For that a glass wafer is glue-bonded onto the backside of the thinned readout chip wafer. After the bump depo...

  16. AE (Acoustic Emission) for Flip-Chip CGA/FCBGA Defect Detection

    Science.gov (United States)

    Ghaffarian, Reza

    2014-01-01

    C-mode scanning acoustic microscopy (C-SAM) is a nondestructive inspection technique that uses ultrasound to show the internal feature of a specimen. A very high or ultra-high-frequency ultrasound passes through a specimen to produce a visible acoustic microimage (AMI) of its inner features. As ultrasound travels into a specimen, the wave is absorbed, scattered or reflected. The response is highly sensitive to the elastic properties of the materials and is especially sensitive to air gaps. This specific characteristic makes AMI the preferred method for finding "air gaps" such as delamination, cracks, voids, and porosity. C-SAM analysis, which is a type of AMI, was widely used in the past for evaluation of plastic microelectronic circuits, especially for detecting delamination of direct die bonding. With the introduction of the flip-chip die attachment in a package; its use has been expanded to nondestructive characterization of the flip-chip solder bumps and underfill. Figure 1.1 compares visual and C-SAM inspection approaches for defect detection, especially for solder joint interconnections and hidden defects. C-SAM is specifically useful for package features like internal cracks and delamination. C-SAM not only allows for the visualization of the interior features, it has the ability to produce images on layer-by-layer basis. Visual inspection; however, is only superior to C-SAM for the exposed features including solder dewetting, microcracks, and contamination. Ideally, a combination of various inspection techniques - visual, optical and SEM microscopy, C-SAM, and X-ray - need to be performed in order to assure quality at part, package, and system levels. This reports presents evaluations performed on various advanced packages/assemblies, especially the flip-chip die version of ball grid array/column grid array (BGA/CGA) using C-SAM equipment. Both external and internal equipment was used for evaluation. The outside facility provided images of the key features

  17. Comparison of thermomigration behaviors between Pb-free flip chip solder joints and microbumps in three dimensional integrated circuits: Bump height effect

    Science.gov (United States)

    Ouyang, Fan-Yi; Jhu, Wei-Cheng

    2013-01-01

    Packaging technology is currently transition from flip chip technology to three dimensional integrated circuits (3D ICs) to meet the requirements of consumer electronic products. Compared to flip chip technology, the dimension of microbumps in 3D ICs is shrunk by a factor of 10. In this study, the behaviors of thermomigration in Pb-free solders of flip chip and 3D ICs are presented. When the bump height is 100 μm in the flip chip samples, the Sn protrusion was observed at the hot end and voids formation at the cold end. However, when the bump height is reduced to 5.8 μm in the 3D IC samples, no significant microstructural evolution of Sn was found; instead, the dissolution of Ni under-bump metallization at hot end was observed. We propose that discrepancy between flip chip solder joints and 3D IC microbumps is mainly attributed to the effect of back stress and the presence of thicker Ni under-bump metallization in the 3D IC packaging. Moreover, the critical temperature gradient in terms of different bump heights is discussed, showing below which there will be no net effect of thermomigration of Sn.

  18. Packaging commercial CMOS chips for lab on a chip integration.

    Science.gov (United States)

    Datta-Chaudhuri, Timir; Abshire, Pamela; Smela, Elisabeth

    2014-05-21

    Combining integrated circuitry with microfluidics enables lab-on-a-chip (LOC) devices to perform sensing, freeing them from benchtop equipment. However, this integration is challenging with small chips, as is briefly reviewed with reference to key metrics for package comparison. In this paper we present a simple packaging method for including mm-sized, foundry-fabricated dies containing complementary metal oxide semiconductor (CMOS) circuits within LOCs. The chip is embedded in an epoxy handle wafer to yield a level, large-area surface, allowing subsequent photolithographic post-processing and microfluidic integration. Electrical connection off-chip is provided by thin film metal traces passivated with parylene-C. The parylene is patterned to selectively expose the active sensing area of the chip, allowing direct interaction with a fluidic environment. The method accommodates any die size and automatically levels the die and handle wafer surfaces. Functionality was demonstrated by packaging two different types of CMOS sensor ICs, a bioamplifier chip with an array of surface electrodes connected to internal amplifiers for recording extracellular electrical signals and a capacitance sensor chip for monitoring cell adhesion and viability. Cells were cultured on the surface of both types of chips, and data were acquired using a PC. Long term culture (weeks) showed the packaging materials to be biocompatible. Package lifetime was demonstrated by exposure to fluids over a longer duration (months), and the package was robust enough to allow repeated sterilization and re-use. The ease of fabrication and good performance of this packaging method should allow wide adoption, thereby spurring advances in miniaturized sensing systems.

  19. Flexible packaging of solid-state integrated circuit chips with elastomeric microfluidics

    Science.gov (United States)

    Zhang, Bowei; Dong, Quan; Korman, Can E.; Li, Zhenyu; Zaghloul, Mona E.

    2013-01-01

    A flexible technology is proposed to integrate smart electronics and microfluidics all embedded in an elastomer package. The microfluidic channels are used to deliver both liquid samples and liquid metals to the integrated circuits (ICs). The liquid metals are used to realize electrical interconnects to the IC chip. This avoids the traditional IC packaging challenges, such as wire-bonding and flip-chip bonding, which are not compatible with current microfluidic technologies. As a demonstration we integrated a CMOS magnetic sensor chip and associate microfluidic channels on a polydimethylsiloxane (PDMS) substrate that allows precise delivery of small liquid samples to the sensor. Furthermore, the packaged system is fully functional under bending curvature radius of one centimetre and uniaxial strain of 15%. The flexible integration of solid-state ICs with microfluidics enables compact flexible electronic and lab-on-a-chip systems, which hold great potential for wearable health monitoring, point-of-care diagnostics and environmental sensing among many other applications.

  20. Flexible packaging of solid-state integrated circuit chips with elastomeric microfluidics

    Science.gov (United States)

    Zhang, Bowei; Dong, Quan; Korman, Can E.; Li, Zhenyu; Zaghloul, Mona E.

    2013-01-01

    A flexible technology is proposed to integrate smart electronics and microfluidics all embedded in an elastomer package. The microfluidic channels are used to deliver both liquid samples and liquid metals to the integrated circuits (ICs). The liquid metals are used to realize electrical interconnects to the IC chip. This avoids the traditional IC packaging challenges, such as wire-bonding and flip-chip bonding, which are not compatible with current microfluidic technologies. As a demonstration we integrated a CMOS magnetic sensor chip and associate microfluidic channels on a polydimethylsiloxane (PDMS) substrate that allows precise delivery of small liquid samples to the sensor. Furthermore, the packaged system is fully functional under bending curvature radius of one centimetre and uniaxial strain of 15%. The flexible integration of solid-state ICs with microfluidics enables compact flexible electronic and lab-on-a-chip systems, which hold great potential for wearable health monitoring, point-of-care diagnostics and environmental sensing among many other applications.

  1. High-Sensitivity Low-Noise Miniature Fluxgate Magnetometers Using a Flip Chip Conceptual Design

    Directory of Open Access Journals (Sweden)

    Chih-Cheng Lu

    2014-07-01

    Full Text Available This paper presents a novel class of miniature fluxgate magnetometers fabricated on a print circuit board (PCB substrate and electrically connected to each other similar to the current “flip chip” concept in semiconductor package. This sensor is soldered together by reversely flipping a 5 cm × 3 cm PCB substrate to the other identical one which includes dual magnetic cores, planar pick-up coils, and 3-D excitation coils constructed by planar Cu interconnections patterned on PCB substrates. Principles and analysis of the fluxgate sensor are introduced first, and followed by FEA electromagnetic modeling and simulation for the proposed sensor. Comprehensive characteristic experiments of the miniature fluxgate device exhibit favorable results in terms of sensitivity (or “responsivity” for magnetometers and field noise spectrum. The sensor is driven and characterized by employing the improved second-harmonic detection technique that enables linear V-B correlation and responsivity verification. In addition, the double magnitude of responsivity measured under very low frequency (1 Hz magnetic fields is experimentally demonstrated. As a result, the maximum responsivity of 593 V/T occurs at 50 kHz of excitation frequency with the second harmonic wave of excitation; however, the minimum magnetic field noise is found to be 0.05 nT/Hz1/2 at 1 Hz under the same excitation. In comparison with other miniature planar fluxgates published to date, the fluxgate magnetic sensor with flip chip configuration offers advances in both device functionality and fabrication simplicity. More importantly, the novel design can be further extended to a silicon-based micro-fluxgate chip manufactured by emerging CMOS-MEMS technologies, thus enriching its potential range of applications in modern engineering and the consumer electronics market.

  2. IC chip stress during plastic package molding

    Energy Technology Data Exchange (ETDEWEB)

    Palmer, D.W.; Benson, D.A.; Peterson, D.W.; Sweet, J.N.

    1998-02-01

    Approximately 95% of the world`s integrated chips are packaged using a hot, high pressure transfer molding process. The stress created by the flow of silica powder loaded epoxy can displace the fine bonding wires and can even distort the metalization patterns under the protective chip passivation layer. In this study the authors developed a technique to measure the mechanical stress over the surface of an integrated circuit during the molding process. A CMOS test chip with 25 diffused resistor stress sensors was applied to a commercial lead frame. Both compression and shear stresses were measured at all 25 locations on the surface of the chip every 50 milliseconds during molding. These measurements have a fine time and stress resolution which should allow comparison with computer simulation of the molding process, thus allowing optimization of both the manufacturing process and mold geometry.

  3. Fabrication method for chip-scale-vacuum-packages based on a chip-to-wafer-process

    Science.gov (United States)

    Bauer, J.; Weiler, D.; Ruß, M.; Heß, J.; Yang, P.; Voß, J.; Arnold, N.,; Vogt, H.

    2010-10-01

    This paper introduces a simple vacuum packaging method which is based on a Chip-to-Wafer process. The MEMS-device is provided with an electroplated solder frame. A Si-lid with the same solder frame is mounted on each die of the wafer using a flip chip process. The same materials for lid and substrate are used in order to reduce the mechanical stress due to the same thermal coefficients of expansion. The resulting cavity between die and lid can be evacuated and hermetically sealed with an eutectic soldering process. The feasibility of the method is demonstrated with an infrared focal plane array (IR-FPA). In this case, the Si-lid acts as an optical window and contains an anti reflective layer for the 8-14 μm wavelength area on both sides. The long-term vacuum stability is supported by a getter film inside the package. This method simplifies the sawing process and has the additional cost benefit that it is possible to package only known good dies.

  4. Photodiodes integration on a suspended ridge structure VOA using 2-step flip-chip bonding method

    Science.gov (United States)

    Kim, Seon Hoon; Kim, Tae Un; Ki, Hyun Chul; Kim, Doo Gun; Kim, Hwe Jong; Lim, Jung Woon; Lee, Dong Yeol; Park, Chul Hee

    2015-01-01

    In this works, we have demonstrated a VOA integrated with mPDs, based on silica-on-silicon PLC and flip-chip bonding technologies. The suspended ridge structure was applied to reduce the power consumption. It achieves the attenuation of 30dB in open loop operation with the power consumption of below 30W. We have applied two-step flipchip bonding method using passive alignment to perform high density multi-chip integration on a VOA with eutectic AuSn solder bumps. The average bonding strength of the two-step flip-chip bonding method was about 90gf.

  5. Silver free III-nitride flip chip light-emitting-diode with wall plug efficiency over 70% utilizing a GaN tunnel junction

    Science.gov (United States)

    Yonkee, B. P.; Young, E. C.; DenBaars, S. P.; Nakamura, S.; Speck, J. S.

    2016-11-01

    A molecular beam epitaxy regrowth technique was demonstrated on standard industrial patterned sapphire substrate light-emitting diode (LED) epitaxial wafers emitting at 455 nm to form a GaN tunnel junction. By using an HF pretreatment on the wafers before regrowth, a voltage of 3.08 V at 20 A/cm2 was achieved on small area devices. A high extraction package was developed for comparison with flip chip devices which utilize an LED floating in silicone over a BaSO4 coated header and produced a peak external quantum efficiency (EQE) of 78%. A high reflectivity mirror was designed using a seven-layer dielectric coating backed by aluminum which has a calculated angular averaged reflectivity over 98% between 400 and 500 nm. This was utilized to fabricate a flip chip LED which had a peak EQE and wall plug efficiency of 76% and 73%, respectively. This flip chip could increase light extraction over a traditional flip chip LED due to the increased reflectivity of the dielectric based mirror.

  6. Reliability of flip-chip bonded RFID die using anisotropic conductive paste hybrid material

    Institute of Scientific and Technical Information of China (English)

    Jun-Sik LEE; Jun-Ki KIM; Mok-Soon KIM; Namhyun KANG; Jong-Hyun LEE

    2011-01-01

    A reliability of flip-chip bonded die as a function of anisotropic conductive paste (ACP) hybrid materials. bonding conditions, and antenna pattern materials was investigated during the assembly of radio frequency identification(RFID) inlay. The optimization condition for flip-chip bonding was determined from the behavior of bonding strength. Under the optimized condition,the shear strength for the antenna printed with paste-type Ag ink was larger than that for Cu antenna. Furthermore, an identification distance was varied from the antenna materials. Comparing with the Ag antenna pattern, the as-bonded die on Cu antenna showed a larger distance of identification, However, the long-term reliability of inlay using the Cu antenna was decreased significantly as a function of aging time at room temperature because of the bended shape of Cu antenna formed during the flip-chip bonding process.

  7. Calculation and Validation of Thermomechanical Stresses in Flip Chip BGA Using the ATC4.2 Test Vehicle

    Energy Technology Data Exchange (ETDEWEB)

    Burchett, S.N.; Mitchell, R.T.; Nguyen, L.; Peterson, D.W.; Sweet, J.N.

    1999-03-09

    We report the first in situ measurements of thermomechanical stresses in a 1000 I/O 250 {micro}m pitch piezoresistive flip chip test chip assembled to a 755 I/O 1.0 mm pitch 35 mm Ball Grid Array (BGA). The BGA substrates employed build-up dielectric layers containing micro-vias over conventional fiberglass laminate cores. Experimental data, which include in situ stress and die bending measurements, were correlated to closed form and Finite Element Method (FEM) calculations. Cracking and delamination were observed in some of the experimental groups undergoing temperature cycling. Through use of bounding conditions in the FEM simulations, these failures were associated with debonding of the underfill fillet from the die edge that caused stresses to shift to weaker areas of the package.

  8. Low temperature co-fired ceramic packaging of CMOS capacitive sensor chip towards cell viability monitoring

    Directory of Open Access Journals (Sweden)

    Niina Halonen

    2016-11-01

    Full Text Available Cell viability monitoring is an important part of biosafety evaluation for the detection of toxic effects on cells caused by nanomaterials, preferably by label-free, noninvasive, fast, and cost effective methods. These requirements can be met by monitoring cell viability with a capacitance-sensing integrated circuit (IC microchip. The capacitance provides a measurement of the surface attachment of adherent cells as an indication of their health status. However, the moist, warm, and corrosive biological environment requires reliable packaging of the sensor chip. In this work, a second generation of low temperature co-fired ceramic (LTCC technology was combined with flip-chip bonding to provide a durable package compatible with cell culture. The LTCC-packaged sensor chip was integrated with a printed circuit board, data acquisition device, and measurement-controlling software. The packaged sensor chip functioned well in the presence of cell medium and cells, with output voltages depending on the medium above the capacitors. Moreover, the manufacturing of microfluidic channels in the LTCC package was demonstrated.

  9. Flip-chip assembly of VCSELs to silicon grating couplers via laser fabricated SU8 prisms.

    Science.gov (United States)

    Kaur, K S; Subramanian, A Z; Cardile, P; Verplancke, R; Van Kerrebrouck, J; Spiga, S; Meyer, R; Bauwelinck, J; Baets, R; Van Steenberge, G

    2015-11-02

    This article presents the flip-chip bonding of vertical-cavity surface-emitting lasers (VCSELs) to silicon grating couplers (GCs) via SU8 prisms. The SU8 prisms are defined on top of the GCs using non-uniform laser ablation process. The prisms enable perfectly vertical coupling from the bonded VCSELs to the GCs. The VCSELs are flip-chip bonded on top of the silicon GCs employing the laser-induced forward transfer (LIFT)-assisted thermocompression technique. An excess loss of transmission experiments performed on the bonded assemblies with clear eye openings up to 20 Gb/s are also presented.

  10. Observation of amorphous chromium in modified C4 flip chip solder joints after thermal stress testing

    Energy Technology Data Exchange (ETDEWEB)

    Hooghan, T.K.; Nakahara, S.; Hooghan, K.; Privette, R.W.; Bachman, M.A.; Moyer, R.S

    2003-08-01

    Flip chip reliability was evaluated using thermal stress tests at 150 deg. C. Electrical failures of flip chip devices were found to occur at the solder/under-bump-metallization interface by forming a porous amorphous chromium layer. The formation of the porous amorphous layer responsible for electrical failures resulted from the outdiffusion of copper atoms from a copper-chromium co-deposit, used as one of the under-bump-metallization layers. A strong interaction of Cu with the Sn component of the solder is the driving force of the Cu outdiffusion.

  11. Heating rate and spin flip lifetime due to near field noise in layered superconducting atom chips

    CERN Document Server

    Fermani, Rachele; Zhang, Bo; Lim, Michael J; Dumke, Rainer

    2009-01-01

    We theoretically investigate the heating rate and spin flip lifetimes due to near field noise for atoms trapped close to layered superconducting structures. In particular, we compare the case of a gold layer deposited above a superconductor with the case of a bare superconductor. We study a niobium-based and a YBCO-based chip. For both niobium and YBCO chips at a temperature of 4.2 K, we find that the deposition of the gold layer can have a significant impact on the heating rate and spin flip lifetime, as a result of the increase of the near field noise. At a chip temperature of 77 K, this effect is less pronounced for the YBCO chip.

  12. High performance thin-film flip-chip InGaN-GaN light-emitting diodes

    Science.gov (United States)

    Shchekin, O. B.; Epler, J. E.; Trottier, T. A.; Margalith, T.; Steigerwald, D. A.; Holcomb, M. O.; Martin, P. S.; Krames, M. R.

    2006-08-01

    Data are presented on the operation of thin-film flip-chip InGaN /GaN multiple-quantum-well light-emitting diodes (LEDs). The combination of thin-film LED concept with flip-chip technology is shown to provide surface brightness and flux output advantages over conventional flip-chip and vertical-injection thin-film LEDs. Performance characteristics of blue, white, and green thin-film flip-chip 1×1mm2 LEDs are described. Blue (˜441nm) thin-film flip-chip LEDs are demonstrated with radiance of 191mW/mm2sr at 1A drive, more than two times brighter than conventional flip-chip LEDs. An encapsulated thin-film flip-chip blue LED lamp is shown to have external quantum efficiency of 38% at forward current of 350mA. A white lamp based on a YAG:Ce phosphor coated device exhibits luminous efficacy of 60lm/W at 350mA with peak efficiency of 96lm/W at 20mA and luminance of 38Mcd/m2 at 1A drive current. Green (˜517nm) devices exhibit luminance of 37Mcd/m2 at 1A.

  13. 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.

  14. Tin-Silver Alloys for Flip-Chip Bonding Studied with a Rotating Cylinder Electrode

    DEFF Research Database (Denmark)

    Tang, Peter Torben; Pedersen, E.H.; Bech-Nielsen, G.;

    1999-01-01

    Electrodeposition of solder for flip-chip bonding is studied in the form of a pyrophosphate/iodide tin-silver alloy bath. The objective is to obtain a uniform alloy composition, with 3.8 At.% silver, over a larger area. This specific alloy will provide an eutectic solder melting at 221°C (or 10°C...

  15. Development of a Fluxless Flip Chip Bonding Process for Optical Military Electronics

    Energy Technology Data Exchange (ETDEWEB)

    Girardi, Michael

    2007-11-11

    As military electronics tend to become lighter, smaller, thinner, and lower cost, the use of flip chip technology is becoming more common place to meet system requirements, yet survive environments. This paper explores the development of an optical flip chip application and details the selection/qualification of the substrate. The selected assembly consists of a procured 1x12 Vertical Cavity Surface Emitting Laser (VCSEL) die, having 80um diameter eutectic AuSn solder bumps at 250um pitch and flip chip bonded to a .006” thick 99.6% alumina substrate with .006” diameter thru holes and metallized with 500Å WTi, under minimum 2.0-3.0μm (80-120μ”) thin film deposited Au. An 8 run, 3 factor, 2 level Full Factorial Design of Experiments (DOE) was completed on procured detector arrays and procured ceramic substrates using the Suss Microtec FC150. The optimum settings for the peak temperature, peak time and final die z-height were selected using the ANOVA results and interaction plots. Additional studies were completed to qualify in-house produced substrates. An epoxy glob-top encapsulant was selected to dissipate stress on the flip chip solder joints and to enhance thermal shock performance.

  16. Characterization of Ni/SnPb-TiW/Pt Flip Chip Interconnections in Silicon Pixel Detector Modules

    CERN Document Server

    Karadzhinova, Aneliya; Härkönen, Jaakko; Luukka, Panja-riina; Mäenpää, Teppo; Tuominen, Eija; Haeggstrom, Edward; Kalliopuska, Juha; Vahanen, Sami; Kassamakov, Ivan

    2014-01-01

    In contemporary high energy physics experiments, silicon detectors are essential for recording the trajectory of new particles generated by multiple simultaneous collisions. Modern particle tracking systems may feature 100 million channels, or pixels, which need to be individually connected to read-out chains. Silicon pixel detectors are typically connected to readout chips by flip-chip bonding using solder bumps. High-quality electro-mechanical flip-chip interconnects minimizes the number of dead read-out channels in the particle tracking system. Furthermore, the detector modules must endure handling during installation and withstand heat generation and cooling during operation. Silicon pixel detector modules were constructed by flip-chip bonding 16 readout chips to a single sensor. Eutectic SnPb solder bumps were deposited on the readout chips and the sensor chips were coated with TiW/Pt thin film UBM (under bump metallization). The modules were assembled at Advacam Ltd, Finland. We studied the uniformity o...

  17. Characterization of integrated circuit packaging materials

    CERN Document Server

    Moore, Thomas

    1993-01-01

    Chapters in this volume address important characteristics of IC packages. Analytical techniques appropriate for IC package characterization are demonstrated through examples of the measurement of critical performance parameters and the analysis of key technological problems of IC packages. Issues are discussed which affect a variety of package types, including plastic surface-mount packages, hermetic packages, and advanced designs such as flip-chip, chip-on-board and multi-chip models.

  18. Cost effective flip chip assembly and interconnection technologies for large area pixel sensor applications

    Energy Technology Data Exchange (ETDEWEB)

    Fritzsch, T., E-mail: thomas.fritzsch@izm.fraunhofer.de [Fraunhofer IZM, Gustav-Meyer-Allee 25, Berlin 13355 (Germany); Jordan, R.; Oppermann, H. [Fraunhofer IZM, Gustav-Meyer-Allee 25, Berlin 13355 (Germany); Ehrmann, O. [Berlin Institute of Technology (TUB), Berlin 10623 (Germany); Toepper, M.; Baumgartner, T.; Lang, K.-D. [Fraunhofer IZM, Gustav-Meyer-Allee 25, Berlin 13355 (Germany)

    2011-09-11

    Much of the cost of manufacturing pixel detectors is due to bumping and flip chip assembly of the readout chips onto sensor tiles, even if it is done on wafer level. To address this issue, Fraunhofer IZM investigated two new technological approaches, namely screen printing using dry film resist and chip-to-wafer assembly. In the first approach, solder bumps with diameters of 80 and 25 {mu}m in pitches of 110 and 60 {mu}m, respectively, were produced by screen-printing solder paste using a photo-structured dry film resist. Results indicated that the technology is a viable high yield and low cost bumping process. The second approach was developed to decrease the number of manual handling steps in pixel module manufacturing, which is critical for reducing processing time and cost. Here, chip designs on 200 mm readout chip (ROC) wafers and 150 mm sensor wafers were especially adapted for chip-to-wafer assembly and to ensure that the interconnection yield and reliability could be tested. After bumping and dicing of the readout chip wafer and UBM plating on the sensor wafer, individual dice were flip chip mounted on the pre-diced sensor wafer. This paper describes the technological steps, key processing parameters and first results for both technologies.

  19. Flip Chip Bonding of a Quartz MEMS-Based Vibrating Beam Accelerometer

    Directory of Open Access Journals (Sweden)

    Jinxing Liang

    2015-09-01

    Full Text Available In this study, a novel method to assemble a micro-accelerometer by a flip chip bonding technique is proposed and demonstrated. Both the main two parts of the accelerometer, a double-ended tuning fork and a base-proof mass structure, are fabricated using a quartz wet etching process on Z cut quartz wafers with a thickness of 100 μm and 300 μm, respectively. The finite element method is used to simulate the vibration mode and optimize the sensing element structure. Taking advantage of self-alignment function of the flip chip bonding process, the two parts were precisely bonded at the desired joint position via AuSn solder. Experimental demonstrations were performed on a maximum scale of 4 × 8 mm2 chip, and high sensitivity up to 9.55 Hz/g with a DETF resonator and a Q value of 5000 in air was achieved.

  20. Flip Chip Bonding of a Quartz MEMS-Based Vibrating Beam Accelerometer.

    Science.gov (United States)

    Liang, Jinxing; Zhang, Liyuan; Wang, Ling; Dong, Yuan; Ueda, Toshitsugu

    2015-09-02

    In this study, a novel method to assemble a micro-accelerometer by a flip chip bonding technique is proposed and demonstrated. Both the main two parts of the accelerometer, a double-ended tuning fork and a base-proof mass structure, are fabricated using a quartz wet etching process on Z cut quartz wafers with a thickness of 100 μm and 300 μm, respectively. The finite element method is used to simulate the vibration mode and optimize the sensing element structure. Taking advantage of self-alignment function of the flip chip bonding process, the two parts were precisely bonded at the desired joint position via AuSn solder. Experimental demonstrations were performed on a maximum scale of 4 × 8 mm² chip, and high sensitivity up to 9.55 Hz/g with a DETF resonator and a Q value of 5000 in air was achieved.

  1. Indium bump array fabrication on small CMOS circuit for flip-chip bonding

    Institute of Scientific and Technical Information of China (English)

    Huang Yuyang; Zhang Yuxiang; Yin Zhizhen; Cui Guoxin; Liu H C; Bian Lifeng; Yang Hui; Zhang Yaohui

    2011-01-01

    We demonstrate a novel method for indium bump fabrication on a small CMOS circuit chip that is to be flip-chip bonded with a GaAs/AlGaAs multiple quantum well spatial light modulator.A chip holder with a via hole is used to coat the photoresist for indium bump lift-off.The 1000 μm-wide photoresist edge bead around the circuit chip can be reduced to less than 500μm,which ensures the integrity of the indium bump array.64 × 64 indium arrays with 20 μm-high,30 μm-diameter bumps are successfully formed on a 5 × 6.5 mm2 CMOS chip.

  2. Reliability evaluation of CIF (chip-in-flex) and COF (chip-on-flex) packages

    Science.gov (United States)

    Jang, Jae-Won; Suk, Kyoung-Lim; Paik, Kyung-Wook; Lee, Soon-Bok

    2010-03-01

    CIF (chip-in-flex) and COF (chip-on-flex) packages have the advantages of fine pitch capability, and flexibility. Anisotropic conductive films (ACFs) are used for the interconnection between chip and substrate. Display, mobile device, and semiconductor industry require for smaller and more integrated packages. Both CIF and COF packages are an alternative for the demands. However, there are some reliability problems of interconnection between the chip and substrate because the packages are subjected to various loading conditions. These may degrade the functionality of the packages. Therefore, reliability assessment of both packages is necessary. In this study, experimental tests were performed to evaluate the reliability of interconnection between the chip and substrate of CIF and COF packages. Thermal cycling tests were performed to evaluate the resistance against thermal fatigue. The shape and warpage of the chip of CIF and COF packages were observed using optical methods (e.g., shadow Moiré and Twyman/Green interferometry). These optical Moiré techniques are widely used for measuring small deformations in microelectronic packages. The stress distribution around the chip was evaluated through FEA (finite element analysis). In addition, we suggested modifying design parameter of CIF packages for the reliability enhancement.

  3. Tin-Silver Alloys for Flip-Chip Bonding Studied with a Rotating Cylinder Electrode

    DEFF Research Database (Denmark)

    Tang, Peter Torben; Pedersen, E.H.; Bech-Nielsen, G.

    1999-01-01

    below pure tin). Depositions on a rotating cylinder electrode (with current screen), followed by composition measurements, provided useful information on the relationship between current density and alloy composition. Preliminary experiments with alloy plating on silicon substrates, with and without......Electrodeposition of solder for flip-chip bonding is studied in the form of a pyrophosphate/iodide tin-silver alloy bath. The objective is to obtain a uniform alloy composition, with 3.8 At.% silver, over a larger area. This specific alloy will provide an eutectic solder melting at 221°C (or 10°C...... photoresist, have shown a stable and promising alternative to pure tin and tin-lead alloys for flip-chip bonding applications....

  4. Flip-chip integration of tilted VCSELs onto a silicon photonic integrated circuit.

    Science.gov (United States)

    Lu, Huihui; Lee, Jun Su; Zhao, Yan; Scarcella, Carmelo; Cardile, Paolo; Daly, Aidan; Ortsiefer, Markus; Carroll, Lee; O'Brien, Peter

    2016-07-25

    In this article we describe a cost-effective approach for hybrid laser integration, in which vertical cavity surface emitting lasers (VCSELs) are passively-aligned and flip-chip bonded to a Si photonic integrated circuit (PIC), with a tilt-angle optimized for optical-insertion into standard grating-couplers. A tilt-angle of 10° is achieved by controlling the reflow of the solder ball deposition used for the electrical-contacting and mechanical-bonding of the VCSEL to the PIC. After flip-chip integration, the VCSEL-to-PIC insertion loss is -11.8 dB, indicating an excess coupling penalty of -5.9 dB, compared to Fibre-to-PIC coupling. Finite difference time domain simulations indicate that the penalty arises from the relatively poor match between the VCSEL mode and the grating-coupler.

  5. Flip-chip-type high-Tc gradiometer for biomagnetic measurements in unshielded environment

    Institute of Scientific and Technical Information of China (English)

    2000-01-01

    A flip-chip-type gradiometer has been constructed with a 10 mm×5 mm planar DC-SQUID gradiometer fabricated on a SrTiO3 bicrystal substrate and a flux transformer made from a YBCO*/YBCO/CeO2/YSZ multilayer on a φ50.8 mm Si wafer. The coupling coefficient between the flux transformer and the planar gradiometer is 0.18. The transformer increases effectively the resolution of the gradiometer. A magnetic field gradient resolution of 73 fT·cm-1·Hz-1/2 in the white region and 596 fT·cm-1Hz-1/2 at 1 Hz has been obtained. High quality magnetocardiogram signals have been successfully measured by using this flip-chip-type gradiometer in an unshielded environment.

  6. Flip-chip-type high- T_c gradiometer for biomagnetic measurements in unshielded environment

    Institute of Scientific and Technical Information of China (English)

    田永君; 王天生; 陈珂; 漆汉宏; 陈烈; 郑东宁; Sven; LINZEN; Frank; SCHMIDL; Paul; SEIDEL

    2000-01-01

    A flip-chip-type gradiometer has been constructed with a 10 mm × 5 mm planar DC-SQUID gradiometer fabricated on a SrTiO3 bicrystal substrate and a flux transformer made from a YB-CO* /YBCO/CeO2/YSZ multilayer on a φ50.8 mm Si wafer. The coupling coefficient between the flux transformer and the planar gradiometer is 0.18. The transformer increases effectively the resolution of the gradiometer. A magnetic field gradient resolution of 73 fT·cm-1·Hz-1/2 in the white region and 596 fT·cm-1Hz-1/2 at 1 Hz has been obtained. High quality magnetocardiogram signals have been successfully measured by using this flip-chip-type gradiometer in an unshielded environment.

  7. UBM Formation on Single Die/Dice for Flip Chip Applications

    OpenAIRE

    Jittinorasett, Suwanna

    1999-01-01

    This thesis presents the low cost process for UBM formation on aluminum pads of single die/dice for Flip Chip applications. The UBM (Under Bump Metallurgy) is required in solder bump structure to provide adhesion/diffusion barrier layer, solder wettable layer, and oxidation barrier layer between the bonding pads of the die and the bumps. Typically, UBM is deposited on the whole wafers by sputtering, evaporation, or electroless plating. These deposition techniques are not practical for UBM ...

  8. Low-loss highly tolerant flip-chip couplers for hybrid integration of Si3N4 and polymer waveguides

    NARCIS (Netherlands)

    Mu, J.; Alexoudi, T.; Yong, Y.S.; Vázquez-Córdova, S.A.; Dijkstra, M.; Worhoff, K.; Duis, J.; Garcia Blanco, S.M.

    2016-01-01

    In this letter, low-loss and highly fabrication-tolerant flip-chip bonded vertical couplers under single-mode condition are demonstrated for the integration of a polymer waveguide chip onto the Si3N4/SiO2 passive platform. The passively aligned vertical couplers have a lateral misalignment between p

  9. Experiment-Based Computational Investigation of Thermomechanical Stresses in Flip Chip BGA Using the ATC4.2 Test Vehicle

    Energy Technology Data Exchange (ETDEWEB)

    Burchett, Steven N.; Nguyen, Luu; Peterson, David W.; Sweet, James N.

    1999-08-02

    Stress measurement test chips were flip chip assembled to organic BGA substrates containing micro-vias and epoxy build-up interconnect layers. Mechanical degradation observed during temperature cycling was correlated to a damage theory developed based on 3D finite element method analysis. Degradation included die cracking, edge delamination and radial fillet cracking.

  10. EVOLUTION OF MICROSTRUCTURE OF Sn-Ag-Cu LEAD-FREE FLIP CHIP SOLDER JOINTS DURING AGING PROCESS

    Institute of Scientific and Technical Information of China (English)

    Y.H. Tian; C.Q. Wang; W.F. Zhou

    2006-01-01

    Flip chip bonding has become a primary technology that has found application in the chip interconnection process in the electronic manufacturing industry in recent years. The solder joints of the flip chip bonding are small and consist of complicated microstructures such as Sn solution,eutectic mixture, and intermetallic compounds (IMCs), whose mechanical performance is quite different from the original solder bulk. The evolution of microstructure of the flip chip solder joints under thermal aging was analyzed. The results show that with an increase in aging time, coarsening of solder bulk matrix and AuSn4 IMCs occurred within the solder. The IMCs that are formed at the bottom side of the flip chip bond were different from those on the top side during the aging process. ( Cu, Ni, Au )6Sn5 were formed at the interfaces of both sides, and large complicated (Au, Ni,Cu)Sn4 IMCs appeared for some time near the bottom interface after aging, but they disappeared again and thus ( Cu, Ni,Au )6Sns IMC thickness increased considerably. The influence of reflow times during the flip chip bonding (as-bonded condition) on the characteristics of interfacial IMCs was weakened when subjected to the aging process.

  11. 75 FR 447 - In the Matter of Certain Semiconductor Chips With Minimized Chip Package Size and Products...

    Science.gov (United States)

    2010-01-05

    ... Certain Semiconductor Chips With Minimized Chip Package Size and Products Containing Same (III); Notice of... States after importation of certain semiconductor chips with minimized chip package size or products... Semiconductor Corporation of Hsinchu, Taiwan; ProMOS Technologies, Inc. of Hsinchu, Taiwan; Ramaxel...

  12. Chip-size-packaged silicon microphones [for hearing instruments

    DEFF Research Database (Denmark)

    Müllenborn, Matthias; Rombach, Pirmin; Klein, Udo;

    2001-01-01

    The first results of silicon microphones that are completely batch-packaged and integrated with signal conditioning circuitry in a chip stack are discussed. The chip stack is designed to be directly mounted into a system, such as a hearing instrument, without further single-chip handling or wire ...... consumption of about 50 μW in the near future, thereby living up to the tight specifications of microphones for hearing instruments. Other potential applications include mobile phones, headsets, and wearable computers, in which space is constrained....

  13. Efficient, tunable flip-chip-integrated III-V/Si hybrid external-cavity laser array.

    Science.gov (United States)

    Lin, Shiyun; Zheng, Xuezhe; Yao, Jin; Djordjevic, Stevan S; Cunningham, John E; Lee, Jin-Hyoung; Shubin, Ivan; Luo, Ying; Bovington, Jock; Lee, Daniel Y; Thacker, Hiren D; Raj, Kannan; Krishnamoorthy, Ashok V

    2016-09-19

    We demonstrate a surface-normal coupled tunable hybrid silicon laser array for the first time using passively-aligned, high-accuracy flip chip bonding. A 2x6 III-V reflective semiconductor optical amplifier (RSOA) array with integrated total internal reflection mirrors is bonded to a CMOS SOI chip with grating couplers and silicon ring reflectors to form a tunable hybrid external-cavity laser array. Waveguide-coupled wall plug efficiency (wcWPE) of 2% and output power of 3 mW has been achieved for all 12 lasers. We further improved the performance by reducing the thickness of metal/dielectric stacks and achieved 10mW output power and 5% wcWPE with the same integration techniques. This non-invasive, one-step back end of the line (BEOL) integration approach provides a promising solution to high density laser sources for future large-scale photonic integrated circuits.

  14. Flip-chip bonding of vertical-cavity surface-emitting lasers using laser-induced forward transfer

    Energy Technology Data Exchange (ETDEWEB)

    Kaur, K. S., E-mail: Kaur.Kamalpreet@elis.ugent.be; Missinne, J.; Van Steenberge, G. [Centre for Microsystems Technology, imec/Ghent University, Technologiepark 914A, B-9052 Gent (Belgium)

    2014-02-10

    This letter reports the use of the Laser-Induced Forward Transfer (LIFT) technique for the fabrication of indium micro-bumps for the flip-chip (FC) bonding of single vertical-cavity surface-emitting laser chips. The FC bonded chips were electrically and optically characterized, and the successful functioning of the devices post-bonding is demonstrated. The die shear and life-time tests carried out on the bonded chips confirmed the mechanical reliability of the LIFT-assisted FC bonded assemblies.

  15. Validating theoretical calculations of thermomechanical stress and deformation using the ATC4.1 flip-chip test vehicle

    Energy Technology Data Exchange (ETDEWEB)

    Peterson, D.W.; Sweet, J.N.; Burchett, S.N.

    1997-08-01

    Two closed form analytical solutions for tri-material thermomechanical stress and deformation, along with one-quarter section finite element model (FEM), were validated using an in-situ CMOS piezoresistive stress measurement test chip that has been repatterened into a fine pitch area array flip-chip. A special printed circuit board substrate for the test chip was designed at Sandia and fabricated by the Hadco Corp. The flip-chip solder attach (FCA) and underfill was performed by a SEMATECH member company. The measured incremental stresses produced by the underfill are reported and discussed for two underfill materials used in this experiment. Detailed comparisons between theory and experiment are presented and discussed.

  16. Investigation of high extraction efficiency flip-chip GaN-based light-emitting diodes

    Institute of Scientific and Technical Information of China (English)

    DA XiaoLi; SHEN GuangDi; XU Chen; ZOU DeShu; ZHU YanXu; ZHANG JianMing

    2009-01-01

    In order to obtain higher light output power, the flip-chip structure Is used. We studied the ratio of the light of GaN sides before and after fabricating metal reflector on p-GaN. The SiO2/SiNx dielectric film reflectors were deposited through plasma enhance chemical vapor deposition following the fabrication of metal reflector, and then the dielectric film reflectors on the electrodes were etched in order to expose the electrodes to the air. It is found that comparing with the flip-chip GaN-LED without dielectric film reflectors, light output power can be increased by as high as 10.2% after the deposition of 2 pairs of SiO2/SiNx dielectric film reflectors on GaN-LEDs, which cover the sidewalls and the areas without the metal reflector. This result indicates that the high reflector formed by multi-layer dielectric films is useful to enhance the light output power of GaN-based LED, which reflects light from step sidewalls and p-GaN without metal reflector to internal, and then light emits from the surface.

  17. Dry-film polymer waveguide for silicon photonics chip packaging.

    Science.gov (United States)

    Hsu, Hsiang-Han; Nakagawa, Shigeru

    2014-09-22

    Polymer waveguide made by dry film process is demonstrated for silicon photonics chip packaging. With 8 μm × 11.5 μm core waveguide, little penalty is observed up to 25 Gbps before or after the light propagate through a 10-km long single-mode fiber (SMF). Coupling loss to SMF is 0.24 dB and 1.31 dB at the polymer waveguide input and output ends, respectively. Alignment tolerance for 0.5 dB loss increase is +/- 1.0 μm along both vertical and horizontal directions for the coupling from the polymer waveguide to SMF. The dry-film polymer waveguide demonstrates promising performance for silicon photonics chip packaging used in next generation optical multi-chip module.

  18. Impact of Isothermal Aging and Testing Temperature on Large Flip-Chip BGA Interconnect Mechanical Shock Performance

    Science.gov (United States)

    Lee, Tae-Kyu; Chen, Zhiqiang; Guirguis, Cherif; Akinade, Kola

    2017-10-01

    The stability of solder interconnects in a mechanical shock environment is crucial for large body size flip-chip ball grid array (FCBGA) electronic packages. Additionally, the junction temperature increases with higher electric power condition, which brings the component into an elevated temperature environment, thus introducing another consideration factor for mechanical stability of interconnection joints. Since most of the shock performance data available were produced at room temperature, the effect of elevated temperature is of interest to ensure the reliability of the device in a mechanical shock environment. To achieve a stable␣interconnect in a dynamic shock environment, the interconnections must tolerate mechanical strain, which is induced by the shock wave input and reaches the particular component interconnect joint. In this study, large body size (52.5 × 52.5 mm2) FCBGA components assembled on 2.4-mm-thick boards were tested with various isothermal pre-conditions and testing conditions. With a heating element embedded in the test board, a test temperature range from room temperature to 100°C was established. The effects of elevated temperature on mechanical shock performance were investigated. Failure and degradation mechanisms are identified and discussed based on the microstructure evolution and grain structure transformations.

  19. Impact of Isothermal Aging and Testing Temperature on Large Flip-Chip BGA Interconnect Mechanical Shock Performance

    Science.gov (United States)

    Lee, Tae-Kyu; Chen, Zhiqiang; Guirguis, Cherif; Akinade, Kola

    2017-06-01

    The stability of solder interconnects in a mechanical shock environment is crucial for large body size flip-chip ball grid array (FCBGA) electronic packages. Additionally, the junction temperature increases with higher electric power condition, which brings the component into an elevated temperature environment, thus introducing another consideration factor for mechanical stability of interconnection joints. Since most of the shock performance data available were produced at room temperature, the effect of elevated temperature is of interest to ensure the reliability of the device in a mechanical shock environment. To achieve a stable interconnect in a dynamic shock environment, the interconnections must tolerate mechanical strain, which is induced by the shock wave input and reaches the particular component interconnect joint. In this study, large body size (52.5 × 52.5 mm2) FCBGA components assembled on 2.4-mm-thick boards were tested with various isothermal pre-conditions and testing conditions. With a heating element embedded in the test board, a test temperature range from room temperature to 100°C was established. The effects of elevated temperature on mechanical shock performance were investigated. Failure and degradation mechanisms are identified and discussed based on the microstructure evolution and grain structure transformations.

  20. Fully additive chip packaging: science or fiction?

    NARCIS (Netherlands)

    Oosterhuis, G.; Zon, C.M.B. van der; Maalderink, H.H.

    2011-01-01

    The current trend in IC packaging towards an ever increasing degree of integration, combined with a high level of production flexibility calls for novel approaches in manufacturing. To address these challenges in a flexible manufacturing setting, TNO investigated to what extend mask-less additive ma

  1. Fully additive chip packaging: science or fiction?

    NARCIS (Netherlands)

    Oosterhuis, G.; Zon, C.M.B. van der; Maalderink, H.H.

    2011-01-01

    The current trend in IC packaging towards an ever increasing degree of integration, combined with a high level of production flexibility calls for novel approaches in manufacturing. To address these challenges in a flexible manufacturing setting, TNO investigated to what extend mask-less additive ma

  2. Fully additive chip packaging: science or fiction?

    NARCIS (Netherlands)

    Oosterhuis, G.; Zon, C.M.B. van der; Maalderink, H.H.

    2011-01-01

    The current trend in IC packaging towards an ever increasing degree of integration, combined with a high level of production flexibility calls for novel approaches in manufacturing. To address these challenges in a flexible manufacturing setting, TNO investigated to what extend mask-less additive

  3. Stresses from flip-chip assembly and underfill; measurements with the ATC4.1 assembly test chip and analysis by finite element method

    Energy Technology Data Exchange (ETDEWEB)

    Peterson, D.W.; Sweet, J.N.; Burchett, S.N.; Hsia, A.

    1996-12-31

    The authors report the first measurements of in-situ flip-chip assembly mechanical stresses using a CMOS piezoresistive test chip repatterned with a fine pitch full area array. A special printed circuit board substrate was designed at Sandia and fabricated by the Hadco Corp. The flip-chip solder attach (FCA) and underfill was performed by a SEMATECH member company. The measured incremental stresses produced by the underfill are reported and discussed for several underfill materials used in this experiment. A FEM of a one-quarter section of the square assembly has been developed to compare with the measured as-assembled and underfill die surface stresses. The initial model utilized linear elastic constitutive models for the Si, solder, underfill, and PC board components. Detailed comparisons between theory and experiment are presented and discussed.

  4. Laser applications in advanced chip packaging

    Science.gov (United States)

    Müller, Dirk; Held, Andrew; Pätzel, Rainer; Clark, Dave; van Nunen, Joris

    2016-03-01

    While applications such as drilling μ-vias and laser direct imaging have been well established in the electronics industry, the mobile device industry's push for miniaturization is generating new demands for packaging technologies that allow for further reduction in feature size while reducing manufacturing cost. CO lasers have recently become available and their shorter wavelength allows for a smaller focus and drilling hole diameters down to 25μm whilst keeping the cost similar to CO2 lasers. Similarly, nanosecond UV lasers have gained significantly in power, become more reliable and lower in cost. On a separate front, the cost of ownership reduction for Excimer lasers has made this class of lasers attractive for structuring redistribution layers of IC substrates with feature sizes down to 2μm. Improvements in reliability and lower up-front cost for picosecond lasers is enabling applications that previously were only cost effective with mechanical means or long-pulsed lasers. We can now span the gamut from 100μm to 2μm for via drilling and can cost effectively structure redistribution layers with lasers instead of UV lamps or singulate packages with picosecond lasers.

  5. Fluxless Bonding Processes Using Silver-Indium System for High Temperature Electronics and Silver Flip-Chip Interconnect Technology

    OpenAIRE

    Wu, Yuan-Yun

    2015-01-01

    In this dissertation, fluxless silver (Ag)-indium (In) binary system bonding and Ag solid-state bonding are used between different bonded pairs which have large thermal expansion coefficient (CTE) mismatch and flip-chip interconnect bonding application. In contrast to the conventional soldering process, fluxless bonding technique eliminates contamination and reliability problems caused by flux to fabricate high quality joints. Due to large CTE mismatch, high quality joints are important to ma...

  6. Au-SN Flip-Chip Solder Bump for Microelectronic and Optoelectronic Applications

    CERN Document Server

    Yoon, Jeong-Won; Koo, Ja-Myeong; Jung, Seung-Boo

    2007-01-01

    As an alternative to the time-consuming solder pre-forms and pastes currently used, a co-electroplating method of eutectic Au-Sn alloy was used in this study. Using a co-electroplating process, it was possible to plate the Au-Sn solder directly onto a wafer at or near the eutectic composition from a single solution. Two distinct phases, Au5Sn and AuSn, were deposited at a composition of 30at.%Sn. The Au-Sn flip-chip joints were formed at 300 and 400 degrees without using any flux. In the case where the samples were reflowed at 300 degrees, only an (Au,Ni)3Sn2 IMC layer formed at the interface between the Au-Sn solder and Ni UBM. On the other hand, two IMC layers, (Au,Ni)3Sn2 and (Au,Ni)3Sn, were found at the interfaces of the samples reflowed at 400 degrees. As the reflow time increased, the thickness of the (Au,Ni)3Sn2 and (Au,Ni)3Sn IMC layers formed at the interface increased and the eutectic lamellae in the bulk solder coarsened.

  7. New Polymer Materials for Microelectronics Packaging

    Institute of Scientific and Technical Information of China (English)

    2005-01-01

    @@ Researchers at the CAS Institute of Chemistry (ICCAS) have made breakthrough progress in developing the manufacturing technology of advanced polymer materials for microelectronics packaging applications. The advanced integrated circuit (IC) packaging polymer materials, including photoimageable polyimide resins and liquid epoxy underfills, are a key issue for FC-BGA/CSP(flip chip-ball grill array/chip scale packaging) which is the main stream for the next generation of microelectronics devices. With the down-sizing, thinning and high I/O (input/output) of IC chips, microelectronics packaging is now facing a big technology challenge.

  8. Ceramic thermal wind sensor based on advanced direct chip attaching package

    Science.gov (United States)

    Lin, Zhou; Ming, Qin; Shengqi, Chen; Bei, Chen

    2014-07-01

    An advanced direct chip attaching packaged two-dimensional ceramic thermal wind sensor is studied. The thermal wind sensor chip is fabricated by metal lift-off processes on the ceramic substrate. An advanced direct chip attaching (DCA) packaging is adopted and this new packaged method simplifies the processes of packaging further. Simulations of the advanced DCA packaged sensor based on computational fluid dynamics (CFD) model show the sensor can detect wind speed and direction effectively. The wind tunnel testing results show the advanced DCA packaged sensor can detect the wind direction from 0° to 360° and wind speed from 0 to 20 m/s with the error less than 0.5 m/s. The nonlinear fitting based least square method in Matlab is used to analyze the performance of the sensor.

  9. 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.

  10. Electromigration and thermomigration studies in composite high lead and eutectic tin-lead flip chip solder joint

    Science.gov (United States)

    Huang, Annie Tzuyu

    The effect of thermomigration and the combination effect of thermomigration and electromigration have been studied in composite SnPb flip chip solder joints. Because Al line on the silicon chip side is the major heat source exerted on flip chip solder joint, temperature gradient across the joint is induced when a long Al line is stressed with high current density. Under a estimated temperature gradient of 1000°C/cm, Sn-rich and Pb-rich phase separation is found to occur. Experimental results have shown that Sn-rich phase accumulates at the hot side and Pb-rich phase accumulates at the cold side after thermomigration. When solder bumps are current high current density, thermomigration was found to accompany electromigration. Not only Pb-rich phase migrated toward the anode side and Sn-rich phase migrated toward the cathode side due to electromigration, Sn-rich phase was found to migrate along the top of solder joint due to thermomigration. It was found that as void propagates along the top of the solder joint, current crowding region shifts with the tip of the void. This created a local hot spot and thus a lateral temperature gradient was induced for thermomigration to occur. To isolate the thermal effect from the current effect, ac stressing at 60 Hz was also utilized. Interestingly, ac seems to have an effect other than thermal effect due to the difference in microstructure evolution between pure thermomigration and ac case after stressing. Further investigation at different frequency is needed to fully understand the effect of ac. Furthermore, analysis was performed to explain the phenomena of phase separation and phase reversal in the solder joint considering a constraint volume within underfill. Both Kirkendall effect and back stress were considered. Finally, detail morphological change after thermomigration and electromigration were investigated. Grain refinement was found to occur at a certain stressing condition. Production of entropy and morphological

  11. Optical properties of plasmonic light-emitting diodes based on flip-chip III-nitride core-shell nanowires.

    Science.gov (United States)

    Nami, Mohsen; Feezell, Daniel F

    2014-12-01

    In this work, we utilize the finite difference time domain (FDTD) method to investigate the Purcell factor, light extraction efficiency (EXE), and cavity quality parameter (Q), and to predict the modulation response of Ag-clad flip-chip GaN/InGaN core-shell nanowire light-emitting diodes (LEDs) with the potential for electrical injection. We consider the need for a pn-junction, the effects of the substrate, and the limitations of nanoscale fabrication techniques in the evaluation. The investigated core-shell nanowire consists of an n-GaN core, surrounded by nonpolar m-plane quantum wells, p-GaN, and silver cladding layers. The core-shell nanowire geometry exhibits a Purcell factor of 57, resulting in a predicted limit of 30 GHz for the 3dB modulation bandwidth.

  12. Electromigration and solid state aging of flip chip solder joints and analysis of tin whisker on lead-frame

    Science.gov (United States)

    Lee, Taekyeong

    Electromigration and solid state aging in flip chip joint, and whisker on lead frame of Pb-containing (eutectic SnPb) and Pb-free solders (SnAg 3.5, SnAg3.8Cu0.7, and SnCu0.7), have been studied systematically, using Scanning Electron Microscopy (SEM), Energy Dispersive X-ray Analysis (EDX), and synchrotron radiation. The high current density in flip chip joint drives the diffusion of atoms of eutectic SnPb and SnAgCu. A marker is used to measure the diffusion flux in a half cross-sectioned solder joint. SnAgCu shows higher resistance against electromigration than eutectic SnPb. In the half cross-sectioned solder joint, void growth is the dominant failure mechanism. However, the whole solder balls in the underfill show that the failure mechanism is a result from the dissolution of electroless Ni under bump metallization (UBM) of about 10 mum thickness. The growth rate between intermetallic compounds in molten and solid solders differed by four orders of magnitude. In liquid solder, the growth rate is about 1 mum/min; the growth rate in solid solder is only about 10 -4 mum/min. The difference is not resulting from factors of thermodynamics, which is the change of Gibbs free energy before and after intermetallic compound formation, but from kinetic factors, which is the rate of change of Gibbs free energy. Even though the difference in growth rate between eutectic SnPb and Pb-free solders during solid state aging was found, the reason behind such difference shown is unclear. The orientation and stress levels of whiskers are measured by white X-ray of synchrotron radiation. The growth direction is nearly parallel to one of the principal axes of tin. The compressive stress level is quite low because the residual stress is relaxed by the whisker growth.

  13. 倒装芯片互连结构中电流聚集研究%Research on the current crowding in flip chip joint

    Institute of Scientific and Technical Information of China (English)

    刘培生; 杨龙龙; 卢颖; 刘亚鸿

    2015-01-01

    Electro-migration becomes a critical reliability issue for high density solder joints in flip chip technology, especially for current crowding. Electro-migration force and mean time to failure of flip chip were analyzed. This study employed two-dimensional simulation to investigate the distribution of current density and Joule heat in the flip chip joint. And the factors that impact the distribution of current density and Joule heat were studied. The results show that the thicknesses of Al and UBM have great influences on the distribution of current density and Joule heat.%由于电流聚集,在倒装芯片封装技术中,电迁移已经成为一个关键的可靠性问题。分析了电迁移力和电迁移中值失效时间,采用二维模型研究了电流密度和焦耳热在倒装芯片互连结构中的分布以及影响电流密度和焦耳热分布的因素。结果表明铝线(Al)和凸点下金属层(UBM)的厚度对电流密度和焦耳热分布有很大的影响。

  14. Materials for advanced packaging

    CERN Document Server

    Wong, CP

    2017-01-01

    This second edition continues to be the most comprehensive review on the developments in advanced electronic packaging technologies, with a focus on materials and processing. Recognized experts in the field contribute to 22 updated and new chapters that provide comprehensive coverage on various 3D package architectures, novel bonding and joining techniques, wire bonding, wafer thinning techniques, organic substrates, and novel approaches to make electrical interconnects between integrated circuit and substrates. Various chapters also address advances in several key packaging materials, including: Lead-free solders Flip chip underfills Epoxy molding compounds Conductive adhesives Die attach adhesives/films Thermal interface materials (TIMS) Materials for fabricating embedded passives including capacitors, inductors, and resistors Materials and processing aspects on wafer-level chip scale package (CSP) and MicroElectroMechanical system (MEMS) Contributors also review new and emerging technologies such as Light ...

  15. A novel approach on fluid dispensing for a DNA/RNA extraction chip package

    Science.gov (United States)

    Xie, Ling; Premachandran, C. S.; Chew, Michelle; Yao, Qiang; Xu, Diao; Pinjala, D.

    2008-02-01

    Micro fluidic package with integrated reservoirs has been developed for DNA /RNA extraction application. A membrane based pump which consists of a reservoir to store reagents and a pin valve to control the fluid is developed to dispense the reagents into the chip. A programmable external actuator is fabricated to dispense the fluid from the membrane pump into the DNA chip. An elastic and high elongation thin rubber membrane is used to seal the membrane pump and at the same time prevent actuator from mixing with different reagents in the micro fluidic package. Break displacement during actuation of membrane pump sealing material is studied with different ratios of PDMS and other types of rubber materials. The fluid flow from the reservoir to the chip is controlled by a pin valve which is activated during the external actuation. A CFD simulation is performed to study the pumping action dusting the external actuation and is validated with experimental results.

  16. Characteristics of intermetallics and micromechanical properties during thermal ageing of Sn-Ag-Cu flip-chip solder interconnects

    Energy Technology Data Exchange (ETDEWEB)

    Li Dezhi [Wolfson School of Mechanical and Manufacturing Engineering, Loughborough University, Loughborough, Leicestershire LE11 3TU (United Kingdom); Liu Changqing [Wolfson School of Mechanical and Manufacturing Engineering, Loughborough University, Loughborough, Leicestershire LE11 3TU (United Kingdom)]. E-mail: c.liu@lboro.ac.uk; Conway, Paul P. [Wolfson School of Mechanical and Manufacturing Engineering, Loughborough University, Loughborough, Leicestershire LE11 3TU (United Kingdom)

    2005-01-25

    Sn-3.8 wt.% Ag-0.7 wt.% Cu solder was applied to Al-1 wt.% Cu bond pads with an electroless nickel (Ni-P) interlayer as an under bump metallisation (UBM). The microstructure and micromechanical properties were studied after ageing at 80 deg. C and 150 deg. C. Two types of intermetallic compounds (IMCs) were identified by electron back-scattered diffraction (EBSD), these being a (Cu, Ni){sub 6}Sn{sub 5} formed at the solder-UBM interface and Ag{sub 3}Sn in the bulk solder. The (Cu, Ni){sub 6}Sn{sub 5} layer grew very slowly during the ageing process, with no Kirkendall voids found by scanning electron microscopy (SEM) after ageing at 80 deg. C. Nano-indentation was used to analyse the mechanical properties of different phases in the solder. Both (Cu, Ni){sub 6}Sn{sub 5} and Ag{sub 3}Sn were harder and more brittle than the {beta}-Sn matrix of the Sn-Ag-Cu alloy. The branch-like morphology of the Ag{sub 3}Sn IMC, especially at the solder-UBM interface, could ultimately be detrimental to the mechanical integrity of the solder when assembled in flip-chip joints.

  17. Inverted tetrahedron-pyramidal micropatterned polymer films for boosting light output power in flip-chip light-emitting diodes.

    Science.gov (United States)

    Leem, Jung Woo; Lee, Soo Hyun; Guan, Xiang-Yu; Yu, Jae Su

    2015-04-20

    We report the improved light output power in gallium nitride-based green flip-chip light-emitting diodes (FCLEDs) employed with inverted tetrahedron-pyramidal micropatterned polydimethylsiloxane (ITPM PDMS) films as an encapsulation and protection layer. The micropatterns are transferred into the surface of PDMS films from the sapphire substrate master molds with two-dimensional periodic hexagonal TPM arrays by a soft imprint lithography method. The ITPM PDMS film laminated on the sapphire dramatically enhances the diffuse transmittance (T(D)) in a wavelength (λ) range of 400-650 nm, exhibiting the larger T(D) value of ~53% at λ = 525 nm, (cf., T(D) ~1% for planar sapphire). By introducing the ITPM PDMS film on the outer surface of sapphire in FCLEDs, the light output power is enhanced, indicating the increment percentage of ~11.1% at 500 mA of injection current compared to the reference FCLED without the ITPM PDMS film, together with better electroluminescence intensity and far-field radiation pattern.

  18. The IronChip evaluation package: a package of perl modules for robust analysis of custom microarrays

    Directory of Open Access Journals (Sweden)

    Brazma Alvis

    2010-03-01

    Full Text Available Abstract Background Gene expression studies greatly contribute to our understanding of complex relationships in gene regulatory networks. However, the complexity of array design, production and manipulations are limiting factors, affecting data quality. The use of customized DNA microarrays improves overall data quality in many situations, however, only if for these specifically designed microarrays analysis tools are available. Results The IronChip Evaluation Package (ICEP is a collection of Perl utilities and an easy to use data evaluation pipeline for the analysis of microarray data with a focus on data quality of custom-designed microarrays. The package has been developed for the statistical and bioinformatical analysis of the custom cDNA microarray IronChip but can be easily adapted for other cDNA or oligonucleotide-based designed microarray platforms. ICEP uses decision tree-based algorithms to assign quality flags and performs robust analysis based on chip design properties regarding multiple repetitions, ratio cut-off, background and negative controls. Conclusions ICEP is a stand-alone Windows application to obtain optimal data quality from custom-designed microarrays and is freely available here (see "Additional Files" section and at: http://www.alice-dsl.net/evgeniy.vainshtein/ICEP/

  19. Method of Images for the Fast Calculation of Temperature Distributions in Packaged VLSI Chips

    CERN Document Server

    Hériz, Virginia Martín; Kemper, T; Kang, S -M; Shakouri, A

    2008-01-01

    Thermal aware routing and placement algorithms are important in industry. Currently, there are reasonably fast Green's function based algorithms that calculate the temperature distribution in a chip made from a stack of different materials. However, the layers are all assumed to have the same size, thus neglecting the important fact that the thermal mounts which are placed underneath the chip can be significantly larger than the chip itself. In an earlier publication, we showed that the image blurring technique can be used to calculate quickly temperature distribution in realistic packages. For this method to be effective, temperature distribution for several point heat sources at the center and at the corner and edges of the chip should be calculated using finite element analysis (FEA) or measured. In addition, more accurate results require correction by a weighting function that will need several FEA simulations. In this paper, we introduce the method of images that take the symmetry of the thermal boundary...

  20. LED flip-chip assembly with electroplated AuSn alloy

    Science.gov (United States)

    Maaskant, P. P.; Akhter, M.; Cordero, N.; Casey, D. P.; Rohan, J. F.; Roycroft, B. J.; Corbett, B. M.

    2005-05-01

    InGaN based high brightness (HB)-LED chips have been fabricated and bonded to substrates that were coated with electroplated Au/Sn/Au solder. The assemblies yielded a forward voltage of 5.6 V and an optical output power of 42 mW when tested at 1,000 mA bias. The electroluminescence distribution was mapped with a CCD camera to determine the current spreading into the p-contact region. Computational fluid dynamics (CFD) was used to check the effect of non-uniform current spreading on the thermal resistance of the assemblies. We show that a good knowledge of the non-uniform heat generation is required to obtain accurate modelling results. The bond strength of the AuSn solder joints exceeded the norm, when shear tested according to MIL-STD-883E (method 2019.5).

  1. Multilayered Microelectronic Device Package With An Integral Window

    Science.gov (United States)

    Peterson, Kenneth A.; Watson, Robert D.

    2004-10-26

    A microelectronic package with an integral window mounted in a recessed lip for housing a microelectronic device. The device can be a semiconductor chip, a CCD chip, a CMOS chip, a VCSEL chip, a laser diode, a MEMS device, or a IMEMS device. The package can be formed of a low temperature co-fired ceramic (LTCC) or high temperature cofired ceramic (HTCC) multilayered material, with the integral window being simultaneously joined (e.g. co-fired) to the package body during LTCC or HTCC processing. The microelectronic device can be flip-chip bonded and oriented so that a light-sensitive side is optically accessible through the window. The result is a compact, low profile package, having an integral window mounted in a recessed lip, that can be hermetically sealed.

  2. Output power enhancement of GaN-based flip-chip light-emitting diodes via conical structures generated by a monolayer of nanospheres

    Science.gov (United States)

    Liu, Mai-Chih; Lin, Chang-Rong; Chan, Chia-Hua

    2016-11-01

    This letter describes the output power enhancement of the GaN-based flip-chip light-emitting diodes (FC LED) featuring conical structures fabricated by etching a self-assembled monolayer SiO2 spheres as the hard mask. By roughening the surface of FC LED components, it increases structural size of the components and elevates the light extraction efficiency of FC LED. At a constant current of 400 mA, the output power of the FC LED with 1200 nm conical structures is 638.1 mW and enhanced by 6.1% compared with the FC LED without surface roughening.

  3. CMOS biosensor system for on-chip cell culture with read-out circuitry and microfluidic packaging.

    Science.gov (United States)

    Welch, David; Christen, Jennifer Blain

    2012-01-01

    A 1.5 mm × 3 mm CMOS chip with sensors for monitoring on-chip cell cultures has been designed. The chip is designed in a 0.5 µm CMOS process which has 3 metal layers and 2 poly layers and is a 5 volt process. The chip contains ion sensitive field effect transistors (ISFETs), as well as ISFETs with read-out circuitry, for monitoring the pH of solutions placed on top of the chip. Interdigitated electrode structures (IDESs) are made using the top metal of the process to be used for sensing cellular attachment and proliferation via impendence. IDES read-out circuits and IDES test structures are included. The chip also contains test amplifiers, bandgap reference test structures, and connections for post-processing. We designed the chip to accommodate packaging into an environment where it will be directly exposed to a cell culture environment. Specifically we designed the chip to have the incorporated sensors near the center of the chip allowing for connections made around the edge of the chip to be sealed off using an epoxy or similar material to prevent shorting. Preliminary electrical characterization results for our amplifier indicate a gain of 48 dB, a bandwidth of 1.65 kHz, and a common mode rejection ratio (CMRR) of 72 dB. We also present a packaging technique using a flexible pcb substrate.

  4. Analysis of the light-extraction efficiency of SiC substrate-based flip-chip vertical light-emitting diodes with embedded photonic crystals

    Science.gov (United States)

    Liu, Meng; Li, Kang; Kong, Fan-min; Zhao, Jia; Zhao, Shu-long; Meng, Hao-tian

    2016-11-01

    To improve the light-extraction efficiency (LEE) of flip-chip vertical light-emitting diodes (LEDs) grown on silicon carbide (SiC) substrate, embedded photonic crystals (PhCs) were alternatively introduced into the n-GaN layer of LEDs, since etching of the SiC substrate was very difficult. The finite-difference time-domain (FDTD) method was employed to investigate the combination effects of the micro-cavity and the embedded PhCs. The influences of the PhCs configurations on the LEE of LEDs were also examined to get an optimal structure. With the optimized parameters, about 20% enhancement of LEE was achieved comparing to planar SiC substrate-based flip-chip vertical LEDs. The LEE of conventional surface PhCs LEDs and double layer PhCs LEDs were also investigated for comparison. The results indicated that LEDs with carefully designed embedded PhCs could provide more LEE than surface PhCs LEDs. The structures proposed here offered scopes for the design of high-efficiency, high-power LEDs.

  5. Compact Shorted Stacked-Patch Antenna Integrated with Chip-Package Based on LTCC Technology

    Directory of Open Access Journals (Sweden)

    Yongjiu Li

    2014-01-01

    Full Text Available A low profile chip-package stacked-patch antenna is proposed by using low temperature cofired ceramic (LTCC technology. The proposed antenna employs a stacked-patch to achieve two operating frequency bands and enhance the bandwidth. The height of the antenna is decreased to 4.09 mm (about λ/25 at 2.45 GHz due to the shorted pin. The package is mounted on a 44 × 44 mm2 ground plane to miniaturize the volume of the system. The design parameters of the antenna and the effect of the antenna on chip-package cavity are carefully analyzed. The designed antenna operates at a center frequency of 2.45 GHz and its impedance bandwidth (S11< -10 dB is 200 MHz, resulting from two neighboring resonant frequencies at 2.41 and 2.51 GHz, respectively. The average gain across the frequency band is about 5.28 dBi.

  6. Microelectronic packaging

    CERN Document Server

    Datta, M; Schultze, J Walter

    2004-01-01

    Microelectronic Packaging analyzes the massive impact of electrochemical technologies on various levels of microelectronic packaging. Traditionally, interconnections within a chip were considered outside the realm of packaging technologies, but this book emphasizes the importance of chip wiring as a key aspect of microelectronic packaging, and focuses on electrochemical processing as an enabler of advanced chip metallization.Divided into five parts, the book begins by outlining the basics of electrochemical processing, defining the microelectronic packaging hierarchy, and emphasizing the impac

  7. Chip-package nano-structured copper and nickel interconnections with metallic and polymeric bonding interfaces

    Science.gov (United States)

    Aggarwal, Ankur

    With the semiconductor industry racing toward a historic transition, nano chips with less than 45 nm features demand I/Os in excess of 20,000 that support computing speed in terabits per second, with multi-core processors aggregately providing highest bandwidth at lowest power. On the other hand, emerging mixed signal systems are driving the need for 3D packaging with embedded active components and ultra-short interconnections. Decreasing I/O pitch together with low cost, high electrical performance and high reliability are the key technological challenges identified by the 2005 International Technology Roadmap for Semiconductors (ITRS). Being able to provide several fold increase in the chip-to-package vertical interconnect density is essential for garnering the true benefits of nanotechnology that will utilize nano-scale devices. Electrical interconnections are multi-functional materials that must also be able to withstand complex, sustained and cyclic thermo-mechanical loads. In addition, the materials must be environmentally-friendly, corrosion resistant, thermally stable over a long time, and resistant to electro-migration. A major challenge is also to develop economic processes that can be integrated into back end of the wafer foundry, i.e. with wafer level packaging. Device-to-system board interconnections are typically accomplished today with either wire bonding or solders. Both of these are incremental and run into either electrical or mechanical barriers as they are extended to higher density of interconnections. Downscaling traditional solder bump interconnect will not satisfy the thermo-mechanical reliability requirements at very fine pitches of the order of 30 microns and less. Alternate interconnection approaches such as compliant interconnects typically require lengthy connections and are therefore limited in terms of electrical properties, although expected to meet the mechanical requirements. A novel chip-package interconnection technology is

  8. Open Ended Microwave Oven for Packaging

    CERN Document Server

    Sinclair, K I; Desmulliez, M Y P; Goussetis, G; Bailey, C; Parrott, K; Sangster, A J

    2008-01-01

    A novel open waveguide cavity resonator is presented for the combined variable frequency microwave curing of bumps, underfills and encapsulants, as well as the alignment of devices for fast flip-chip assembly, direct chip attach (DCA) or wafer-scale level packaging (WSLP). This technology achieves radio frequency (RF) curing of adhesives used in microelectronics, optoelectronics and medical devices with potential simultaneous micron-scale alignment accuracy and bonding of devices. In principle, the open oven cavity can be fitted directly onto a flip-chip or wafer scale bonder and, as such, will allow for the bonding of devices through localised heating thus reducing the risk to thermally sensitive devices. Variable frequency microwave (VFM) heating and curing of an idealised polymer load is numerically simulated using a multi-physics approach. Electro-magnetic fields within a novel open ended microwave oven developed for use in micro-electronics manufacturing applications are solved using a de icated Yee sche...

  9. Thermal Characteristics of InGaN/GaN Flip-Chip Light Emitting Diodes with Diamond-Like Carbon Heat-Spreading Layers

    Directory of Open Access Journals (Sweden)

    Pai-Yang Tsai

    2014-01-01

    Full Text Available The temperature-dependent optical, electrical, and thermal properties of flip-chip light emitting diodes (FCLEDs with diamond-like carbon (DLC heat-spreading layers were investigated. On the basis of the measured results in the 20°C to 100°C temperature range, a significant performance improvement can be achieved for FCLEDs with DLC heat-spreading layers (DLC-FCLED compared with FCLEDs without DLC heat-spreading layers (non-DLC-FCLED. The external quantum efficiency (EQE of the DLC-FCLED improves by 9% at an injection current of 1000 mA and a temperature of 100°C. The forward voltage and spectra variations are smaller than those of non-DLC-FCLEDs. The DLC-FCLED provides high efficiency and high stability performance for high-power and high-temperature applications.

  10. Flipped Learning

    DEFF Research Database (Denmark)

    Holmboe, Peter; Hachmann, Roland

    I FLIPPED LEARNING – FLIP MED VIDEO kan du læse om, hvordan du som underviser kommer godt i gang med at implementere video i undervisning, der har afsæt i tankerne omkring flipped learning. Bogen indeholder fire dele: I Del 1 fokuserer vi på det metarefleksive i at tænke video ind i undervisningen...

  11. Interface analysis of embedded chip resistor device package and its effect on drop shock reliability.

    Science.gov (United States)

    Park, Se-Hoon; Kim, Sun Kyoung; Kim, Young-Ho

    2012-04-01

    In this study, the drop reliability of an embedded passive package is investigated under JESD22-B111 condition. Chip resistors were buried in a PCB board, and it was electrically interconnected by electroless and electrolytic copper plating on a tin pad of a chip resistor without intermetallic phase. However tin, nickel, and copper formed a complex intermetallic phase, such as (Cu, Ni)6Sn5, (Cu, Ni)3Sn, and (Ni, Cu)3Sn2, at the via interface and via wall after reflow and aging. Since the amount of the tin layer was small compared with the solder joint, excessive intermetallic layer growth was not observed during thermal aging. Drop failures are always initiated at the IMC interface, and as aging time increases Cu-Sn-Ni IMC phases are transformed continuously due to Cu diffusion. We studied the intermetallic formation of the Cu via interface and simulated the stress distribution of drop shock by using material properties and board structure of embedded passive boards. The drop simulation was conducted according to the JEDEC standard. It was revealed that the crack starting point related to failure fracture changed due to intermetallic phase transformation along the via interface, and the position where failure occurs experimentally agrees well with our simulation results.

  12. An ultra-small, low-power, all-optical flip-flop memory on a silicon chip

    DEFF Research Database (Denmark)

    Liu, Liu; Kumar, R.; Huybrechts, K.

    2010-01-01

    Ultra-small, low-power, all-optical switching and memory elements, such as all-optical flip-flops, as well as photonic integrated circuits of many such elements, are in great demand for all-optical signal buffering, switching and processing. Silicon-on-insulator is considered to be a promising......-flop working in a continuous-wave regime with an electrical power consumption of a few milliwatts, allowing switching in 60 ps with 1.8 fJ optical energy. The total power consumption and the device size are, to the best of our knowledge, the smallest reported to date at telecom wavelengths. This is also...

  13. Reliability and Characteristics of Wafer-Level Chip-Scale Packages under Current Stress

    Science.gov (United States)

    Chen, Po-Ying; Kung, Heng-Yu; Lai, Yi-Shao; Hsiung Tsai, Ming; Yeh, Wen-Kuan

    2008-02-01

    In this work, we present a novel approach and method for elucidating the characteristics of wafer-level chip-scale packages (WLCSPs) for electromigration (EM) tests. The die in WLCSP was directly attached to the substrate via a soldered interconnect. The shrinking of the area of the die that is available for power, and the solder bump also shrinks the volume and increases the density of electrons for interconnect efficiency. The bump current density now approaches to 106 A/cm2, at which point the EM becomes a significant reliability issue. As known, the EM failure depends on numerous factors, including the working temperature and the under bump metallization (UBM) thickness. A new interconnection geometry is adopted extensively with moderate success in overcoming larger mismatches between the displacements of components during current and temperature changes. Both environments and testing parameters for WLCSP are increasingly demanded. Although failure mechanisms are considered to have been eliminated or at least made manageable, new package technologies are again challenging its process, integrity and reliability. WLCSP technology was developed to eliminate the need for encapsulation to ensure compatibility with smart-mount technology (SMT). The package has good handing properties but is now facing serious reliability problems. In this work, we investigated the reliability of a WLCSP subjected to different accelerated current stressing conditions at a fixed ambient temperature of 125 °C. A very strong correlation exists between the mean time to failure (MTTF) of the WLCSP test vehicle and the mean current density that is carried by a solder joint. A series of current densities were applied to the WLCSP architecture; Black's power law was employed in a failure mode simulation. Additionally, scanning electron microscopy (SEM) was adopted to determine the differences existing between high- and low-current-density failure modes.

  14. Flipped Learning

    DEFF Research Database (Denmark)

    Hachmann, Roland; Holmboe, Peter

    arbejde med faglige problemstillinger gennem problembaserede og undersøgende didaktiske designs. Flipped Learning er dermed andet og mere end at distribuere digitale materialer til eleverne forud for undervisning. Flipped Learning er i lige så høj grad et syn på, hvordan undervisning med digitale medier...

  15. Integrated microsystems packaging approach with LCP

    Science.gov (United States)

    Jaynes, Paul; Shacklette, Lawrence W.

    2006-05-01

    Within the government communication market there is an increasing push to further miniaturize systems with the use of chip-scale packages, flip-chip bonding, and other advances over traditional packaging techniques. Harris' approach to miniaturization includes these traditional packaging advances, but goes beyond this level of miniaturization by combining the functional and structural elements of a system, thus creating a Multi-Functional Structural Circuit (MFSC). An emerging high-frequency, near hermetic, thermoplastic electronic substrate material, Liquid Crystal Polymer (LCP), is the material that will enable the combination of the electronic circuit and the physical structure of the system. The first embodiment of this vision for Harris is the development of a battlefield acoustic sensor module. This paper will introduce LCP and its advantages for MFSC, present an example of the work that Harris has performed, and speak to LCP MFSCs' potential benefits to miniature communications modules and sensor platforms.

  16. Decoupling contact and mirror: an effective way to improve the reflector for flip-chip InGaN/GaN-based light-emitting diodes

    Science.gov (United States)

    Zhu, Binbin; Liu, Wei; Lu, Shunpeng; Zhang, Yiping; Hasanov, Namig; Zhang, Xueliang; Ji, Yun; Zhang, Zi-Hui; Tiam Tan, Swee; Liu, Hongfei; Demir, Hilmi Volkan

    2016-07-01

    In the conventional fabrication process of the widely-adopted Ni/Ag/Ti/Au reflector for InGaN/GaN-based flip-chip light-emitting diodes (LEDs), the contact and the mirror are entangled together with contrary processing conditions which set constraints to the device performance severely. Here we first report the concept and its effectiveness of decoupling the contact formation and the mirror construction. The ohmic contact is first formed by depositing and annealing an extremely thin layer of Ni/Ag on top of p-GaN. The mirror construction is then carried out by depositing thick layer of Ag/Ti/Au without any annealing. Compared with the conventional fabrication method of the reflector, by which the whole stack of Ni/Ag/Ti/Au is deposited and annealed together, the optical output power is improved by more than 70% at 350 mA without compromising the electrical performance. The mechanism of decoupling the contact and the mirror is analyzed with the assistance of contactless sheet resistance measurement and secondary ion mass spectrometry (SIMS) depth profile analysis.

  17. Modification of internal quantum efficiency and efficiency droop in GaN-based flip-chip light-emitting diodes via the Purcell effect.

    Science.gov (United States)

    Ryu, Han-Youl

    2015-09-21

    The Purcell effect in GaN-based flip-chip (FC) light-emitting diode (LED) structures is investigated numerically using finite-difference time-domain simulations. Depending on the thickness of the p-GaN layer, the variation of the Purcell factor of FC LEDs is obtained to be as high as 20%, which results in the relative modification of the internal quantum efficiency (IQE) as large as 8% and 2.5% for the unmodified IQE of 0.4 and 0.8, respectively. Since the influence of the Purcell effect becomes more conspicuous as the IQE decreases, the Purcell enhancement can be advantageously used to mitigate the efficiency droop problem to some extent. When the Purcell effect is positively applied to the blue LED with the peak IQE of 0.8 and the droop ratio of 29.1%, the peak IQE and the droop ratio are found to be improved to 0.82 and 26.3%. This small but non-negligible effect on IQE is expected to be importantly adopted for industry development of high efficiency LEDs.

  18. Performance Improvement of GaN-Based Flip-Chip White Light-Emitting Diodes with Diffused Nanorod Reflector and with ZnO Nanorod Antireflection Layer

    Directory of Open Access Journals (Sweden)

    Hsin-Ying Lee

    2014-01-01

    Full Text Available The GaN-based flip-chip white light-emitting diodes (FCWLEDs with diffused ZnO nanorod reflector and with ZnO nanorod antireflection layer were fabricated. The ZnO nanorod array grown using an aqueous solution method was combined with Al metal to form the diffused ZnO nanorod reflector. It could avoid the blue light emitted out from the Mg-doped GaN layer of the FCWLEDs, which caused more blue light emitted out from the sapphire substrate to pump the phosphor. Moreover, the ZnO nanorod array was utilized as the antireflection layer of the FCWLEDs to reduce the total reflection loss. The light output power and the phosphor conversion efficiency of the FCWLEDs with diffused nanorod reflector and 250 nm long ZnO nanorod antireflection layer were improved from 21.15 mW to 23.90 mW and from 77.6% to 80.1% in comparison with the FCWLEDs with diffused nanorod reflector and without ZnO nanorod antireflection layer, respectively.

  19. Comparison of Sn-Ag-Cu Solder Alloy Intermetallic Compound Growth Under Different Thermal Excursions for Fine-Pitch Flip-Chip Assemblies

    Science.gov (United States)

    Tian, Ye; Liu, Xi; Chow, Justin; Wu, Yi Ping; Sitaraman, Suresh K.

    2013-08-01

    The intermetallic compound (IMC) evolution in Cu pad/Sn-Ag-Cu solder interface and Sn-Ag-Cu solder/Ni pad interface was investigated using thermal shock experiments with 100- μm-pitch flip-chip assemblies. The experiments show that low standoff height of solder joints and high thermomechanical stress play a great role in the interfacial IMC microstructure evolution under thermal shock, and strong cross-reaction of pad metallurgies is evident in the intermetallic growth. Furthermore, by comparing the IMC growth during thermal aging and thermal shock, it was found that thermal shock accelerates IMC growth and that kinetic models based on thermal aging experiments underpredict IMC growth in thermal shock experiments. Therefore, new diffusion kinetic parameters were determined for the growth of (Cu,Ni)6Sn5 using thermal shock experiments, and the Cu diffusion coefficient through the IMC layer was calculated to be 0.2028 μm2/h under thermal shock. Finite-element models also show that the solder stresses are higher under thermal shock, which could explain why the IMC growth is faster and greater under thermal shock cycling as opposed to thermal aging.

  20. Improvement of Light Extraction Efficiency in Flip-Chip Light Emitting Diodes on SiC Substrate via Transparent Haze Films with Morphology-Controlled Collapsed Alumina Nanorods.

    Science.gov (United States)

    Baek, Seunghwa; Kang, Gumin; Shin, Dongheok; Bae, Kyuyoung; Kim, Yong Hyun; Kim, Kyoungsik

    2016-01-13

    We demonstrate GaN-based flip-chip light emitting diodes (FC-LEDs) on SiC substrate achieving high extraction efficiency by simply attaching the optically transparent haze films consisting of collapsed alumina nanorods. Through controlled etching time of alumina nanorods, we obtain four types of films that have different morphologies with different optical transmittance and haze properties. We show that the light output power of the FC-LEDs with film, which has 95.6% transmittance and 62.7% haze, increases by 20.4% in comparison to the bare LEDs. The angular radiation pattern of the LEDs also follows the Lambertian emission pattern without deteriorating the electrical properties of the device. The improvement of light extraction is mainly attributed to the reduced total internal reflection (TIR) via efficient out-coupling of guided light from SiC substrate to air by collapsed alumina nanorod structures in the film. The high transparency of film and reduced Fresnel reflection via graded refractive index transition between the film and SiC substrate also contribute to the extraction enhancement of the device. We systematically investigate the influence of haze film's geometrical or optical properties on the extraction efficiency of FC-LEDs, and this study will provide a novel approach to enhance the performance of various optoelectronic devices.

  1. Heat Transfer Characteristics in High Power LED Packaging

    OpenAIRE

    Chi-Hung Chung; Kai-Shing Yang; Kuo-Hsiang Chien; Ming-Shan Jeng; Ming-Tsang Lee

    2014-01-01

    This study uses the T3Ster transient thermal resistance measuring device to investigate the effects to heat transfer performances from different LED crystal grains, packaging methods and heat-sink substrates through the experimental method. The experimental parameters are six different types of LED modules that are made alternatively with the crystal grain structure, the die attach method and the carrying substrate. The crystal grain structure includes the lateral type, flip chip type and ver...

  2. ChIPpeakAnno: a Bioconductor package to annotate ChIP-seq and ChIP-chip data

    Directory of Open Access Journals (Sweden)

    Pagès Hervé

    2010-05-01

    Full Text Available Abstract Background Chromatin immunoprecipitation (ChIP followed by high-throughput sequencing (ChIP-seq or ChIP followed by genome tiling array analysis (ChIP-chip have become standard technologies for genome-wide identification of DNA-binding protein target sites. A number of algorithms have been developed in parallel that allow identification of binding sites from ChIP-seq or ChIP-chip datasets and subsequent visualization in the University of California Santa Cruz (UCSC Genome Browser as custom annotation tracks. However, summarizing these tracks can be a daunting task, particularly if there are a large number of binding sites or the binding sites are distributed widely across the genome. Results We have developed ChIPpeakAnno as a Bioconductor package within the statistical programming environment R to facilitate batch annotation of enriched peaks identified from ChIP-seq, ChIP-chip, cap analysis of gene expression (CAGE or any experiments resulting in a large number of enriched genomic regions. The binding sites annotated with ChIPpeakAnno can be viewed easily as a table, a pie chart or plotted in histogram form, i.e., the distribution of distances to the nearest genes for each set of peaks. In addition, we have implemented functionalities for determining the significance of overlap between replicates or binding sites among transcription factors within a complex, and for drawing Venn diagrams to visualize the extent of the overlap between replicates. Furthermore, the package includes functionalities to retrieve sequences flanking putative binding sites for PCR amplification, cloning, or motif discovery, and to identify Gene Ontology (GO terms associated with adjacent genes. Conclusions ChIPpeakAnno enables batch annotation of the binding sites identified from ChIP-seq, ChIP-chip, CAGE or any technology that results in a large number of enriched genomic regions within the statistical programming environment R. Allowing users to pass their

  3. Semiconductor Yield Analysis and Multi-Chip Package (MCP) Die Pairing Optimization using Machine Learning

    Institute of Scientific and Technical Information of China (English)

    Randall Goodwin; Russell Miller; Eugene Tuv; Alexander Borisov

    2006-01-01

    Machine Learning, Artificial Intelligence (AI) and Statistical Learning are related mathematical fields which utilize computer algorithms to create models for the purposes of data description and/or prediction. Some well known examples include biometric identification and authorization systems, speech recognition and user targeted internet advertising. Statistical Learning, which we will use in this paper, also has many applications in semiconductor manufacturing.Some of the challenging characteristics of semiconductor data include high dimensionality, mixtures of categorical and numeric data, non-randomly missing data, non-Gaussian and multimodal distributions, nonlinear complex relationships, noise, outliers and temporal dependencies. These challenges are becoming particularly acute as the quantity of available data increases and the ability to trace lots, wafers, die, and packages throughout the full fab, wafer test, assembly and final test manufacturing flow improves. Statistical-learning techniques are applied to address these challenges. In this paper we discuss the advancement and applications of Tree based classification and regression methods to semiconductor data. We begin the paper with a description of the problem, followed by and overview of the statistical-learning techniques we use in our case studies. We then describe how the challenges presented by semiconductor data were addressed with original extensions to tree-based and kernel-based methods. Next, we review four case studies: home sales price prediction, signal identification/separation, final speed bin classification and die pairing optimization for Multi-Chip Packages (MCP). Results from the case studies demonstrate how statistical-learning addresses the challenges presented by semiconductor manufacturing data and enables improved data discovery and prediction when compared to traditional statistical approaches.

  4. Nutrition labelling, marketing techniques, nutrition claims and health claims on chip and biscuit packages from sixteen countries.

    Science.gov (United States)

    Mayhew, Alexandra J; Lock, Karen; Kelishadi, Roya; Swaminathan, Sumathi; Marcilio, Claudia S; Iqbal, Romaina; Dehghan, Mahshid; Yusuf, Salim; Chow, Clara K

    2016-04-01

    Food packages were objectively assessed to explore differences in nutrition labelling, selected promotional marketing techniques and health and nutrition claims between countries, in comparison to national regulations. Cross-sectional. Chip and sweet biscuit packages were collected from sixteen countries at different levels of economic development in the EPOCH (Environmental Profile of a Community's Health) study between 2008 and 2010. Seven hundred and thirty-seven food packages were systematically evaluated for nutrition labelling, selected promotional marketing techniques relevant to nutrition and health, and health and nutrition claims. We compared pack labelling in countries with labelling regulations, with voluntary regulations and no regulations. Overall 86 % of the packages had nutrition labels, 30 % had health or nutrition claims and 87 % displayed selected marketing techniques. On average, each package displayed two marketing techniques and one health or nutrition claim. In countries with mandatory nutrition labelling a greater proportion of packages displayed nutrition labels, had more of the seven required nutrients present, more total nutrients listed and higher readability compared with those with voluntary or no regulations. Countries with no health or nutrition claim regulations had fewer claims per package compared with countries with regulations. Nutrition label regulations were associated with increased prevalence and quality of nutrition labels. Health and nutrition claim regulations were unexpectedly associated with increased use of claims, suggesting that current regulations may not have the desired effect of protecting consumers. Of concern, lack of regulation was associated with increased promotional marketing techniques directed at children and misleadingly promoting broad concepts of health.

  5. Design of Antenna-on-Chip, Antenna-on-Package and Detectors from RF, Microwave to THz Frequency Range in SiGe-C Technology

    NARCIS (Netherlands)

    Wane, S; Bardy, S.; Heijster, R.M.E.M. van; Goulet, F.; Gamand, P.

    2011-01-01

    Design solutions for on-chip signal detectors, Antenna-on- Chip and Antenna-on-Package (with Bond Wire elements), from RF, Microwave to THz frequency range, using state-of-theart SiGe BiCMOS technology are presented. Both CML and CMOS detectors are designed, fabricated and compared in terms of their

  6. FlexiChip package: an universal microarray with a dedicated analysis software for high-thoughput SNPs detection linked to anti-malarial drug resistance

    Directory of Open Access Journals (Sweden)

    Dondorp Arjen M

    2009-10-01

    Full Text Available Abstract Background A number of molecular tools have been developed to monitor the emergence and spread of anti-malarial drug resistance to Plasmodium falciparum. One of the major obstacles to the wider implementation of these tools is the absence of practical methods enabling high throughput analysis. Here a new Zip-code array is described, called FlexiChip, linked to a dedicated software program, which largely overcomes this problem. Methods Previously published microarray probes detecting single-nucleotide polymorphisms (SNP associated with parasite resistance to anti-malarial drugs (ResMalChip were adapted for a universal microarray FlexiChip format. To evaluate the overall sensitivity of the FlexiChip package (microarray + software, the results of FlexiChip were compared to ResMalChip microarray, using the same extension probes and with the same PCR products. In both cases, sequence results were used as gold standard to calculate sensitivity and specificity. FlexiChip results obtained with a set of field isolates were then compared to those assessed in an independent reference laboratory. Results The FlexiChip package gave results identical to the ResMalChip results in 92.7% of samples (kappa coefficient 0.8491, with a standard error 0.021 and had a sensitivity of 95.88% and a specificity of 97.68% compared to the sequencing as the reference method. Moreover the method performed well compared to the results obtained in the reference laboratories, with 99.7% of identical results (kappa coefficient 0.9923, S.E. 0.0523. Conclusion Microarrays could be employed to monitor P. falciparum drug resistance markers with greater cost effectiveness and the possibility for high throughput analysis. The FlexiChip package is a promising tool for use in poor resource settings of malaria endemic countries.

  7. Flipped Physics

    Science.gov (United States)

    Kettle, Maria

    2013-01-01

    This paper defines flipped learning and then examines its practical implementation in AS and A2 level physics classes, that is, classes for 16-18 year olds. The effect of this teaching style on student learning behaviour and its impact on test results are evaluated. The paper recounts the difficulties of implementing it and evaluates student…

  8. Flipped Physics

    Science.gov (United States)

    Kettle, Maria

    2013-01-01

    This paper defines flipped learning and then examines its practical implementation in AS and A2 level physics classes, that is, classes for 16-18 year olds. The effect of this teaching style on student learning behaviour and its impact on test results are evaluated. The paper recounts the difficulties of implementing it and evaluates student…

  9. Embeded photonic crystal at the interface of p-GaN and Ag reflector to improve light extraction of GaN-based flip-chip light-emitting diode

    Energy Technology Data Exchange (ETDEWEB)

    Zhen, Aigong; Ma, Ping, E-mail: maping@semi.ac.cn; Zhang, Yonghui; Guo, Enqing; Tian, Yingdong; Liu, Boting; Guo, Shikuan; Shan, Liang; Wang, Junxi; Li, Jinmin [Semiconductor Lighting R and D Center, Institute of Semiconductors, Chinese Academy of Sciences, Beijing 100083 (China)

    2014-12-22

    In this experiment, a flip-chip light-emitting diode with photonic crystal was fabricated at the interface of p-GaN and Ag reflector via nanospheres lithography technique. In this structure, photonic crystal could couple with the guide-light efficiently by reason of the little distance between photonic crystal and active region. The light output power of light emitting diode with embedded photonic crystal was 1.42 times larger than that of planar flip-chip light-emitting diode. Moreover, the embedded photonic crystal structure makes the far-field divergence angle decreased by 18° without spectra shift. The three-dimensional finite difference time domain simulation results show that photonic crystal could improve the light extraction, and enhance the light absorption caused by Ag reflector simultaneously, because of the roughed surface. The depth of photonic crystal is the key parameter affecting the light extraction and absorption. Light extraction efficiency increases with the depth photonic crystal structure rapidly, and reaches the maximum at the depth 80 nm, beyond which light extraction decrease drastically.

  10. Characterisation of hybrid integrated all-optical flip-flop

    DEFF Research Database (Denmark)

    Liu, Y.; McDougall, R.; Seoane, Jorge

    2006-01-01

    We present a fully-packaged, hybrid-integrated all-optical flip-flop with separate optical set and reset operation. The flip-flop can control a wavelength converter to route 40 Gb/s data packets all-optically. The experimental results are given.......We present a fully-packaged, hybrid-integrated all-optical flip-flop with separate optical set and reset operation. The flip-flop can control a wavelength converter to route 40 Gb/s data packets all-optically. The experimental results are given....

  11. Integração de microssensores a microlaboratórios autônomos através de técnicas de montagem por viragem (Flip-Chip).

    OpenAIRE

    Valtemar Fernandes Cardoso

    2014-01-01

    Neste trabalho é apresentada a análise de técnicas para a integração de ISFETs (Ion Selective Field Effect Transitors), através do método de montagem por viragem (Flip-chip) usando pasta de solda livre de chumbo e epóxi condutivo de prata, com o objetivo de permitir sua aplicação em Microssistemas de Análise Total (µTAS). Para os testes de integração foram construídas estruturas em dois substratos, o FR-4, pelo método de ligação por fios (wire bonding), e o LTCC, que pode ser aplicado na cons...

  12. Adapting MCM-D technology to a piezoresistive accelerometer packaging

    Science.gov (United States)

    Collado, A.; Plaza, J. A.; Cabruja, E.; Esteve, J.

    2003-07-01

    A silicon-on-silicon multichip module for a piezoresistive accelerometer is presented in this paper. This packaging technology, a type of wafer level packaging, offers fully complementary metal-oxide semiconductor compatible silicon substrates, so a pre-amplification stage can be included at substrate level. The electrical contacts and a partial sealing of the sensor mobile structures are performed at the same step using flip-chip technology, so the cost is reduced. As accelerometers are stress-sensitive devices, great care must be taken in the fabrication process and materials. Thus, test structures have been included to study the packaging effects. In this paper we report on the compatibility of accelerometer and wafer level packaging technologies.

  13. Development of Equivalent Material Properties of Microbump for Simulating Chip Stacking Packaging

    Directory of Open Access Journals (Sweden)

    Chang-Chun Lee

    2015-08-01

    Full Text Available three-dimensional integrated circuit (3D-IC structure with a significant scale mismatch causes difficulty in analytic model construction. This paper proposes a simulation technique to introduce an equivalent material composed of microbumps and their surrounding wafer level underfill (WLUF. The mechanical properties of this equivalent material, including Young’s modulus (E, Poisson’s ratio, shear modulus, and coefficient of thermal expansion (CTE, are directly obtained by applying either a tensile load or a constant displacement, and by increasing the temperature during simulations, respectively. Analytic results indicate that at least eight microbumps at the outermost region of the chip stacking structure need to be considered as an accurate stress/strain contour in the concerned region. In addition, a factorial experimental design with analysis of variance is proposed to optimize chip stacking structure reliability with four factors: chip thickness, substrate thickness, CTE, and E-value. Analytic results show that the most significant factor is CTE of WLUF. This factor affects microbump reliability and structural warpage under a temperature cycling load and high-temperature bonding process. WLUF with low CTE and high E-value are recommended to enhance the assembly reliability of the 3D-IC architecture.

  14. Flipping HCI

    Directory of Open Access Journals (Sweden)

    C. Evans

    2016-08-01

    Full Text Available This paper presents the results of two studies involving “flipping the classroom”. Teaching material was delivered via interactive “e-lectures”, allowing face-to-face sessions to focus instead on practice. The e-lectures were designed according to standard usability principles coupled with recent research into the effect of interactivity on learning. The effectiveness of the use of e-lectures was then evaluated using an online survey. The results suggest that students prefer the flexibility offered by e-lectures compared to conventional lectures. The results contribute to our understanding of how this technology fits with face-to-face teaching in the digital age.

  15. Simulation and analysis of effects of Young's modulus of isolation material on natural frequencies of the sensor package and displacement of the chip

    Institute of Scientific and Technical Information of China (English)

    YIN Jing-hua; LV Guang-jun; LIU Xiao-wei; LEI Qing-quan

    2005-01-01

    For the first time an anti-shock packaging model of an acoustic-vibration sensor system has been designed by using the shocking isolation principle. The finite element analysis has been applied for design and simulation of the model. The effects of Young's modulus of anti-shock rubber on naturally occurring frequencies of the combination of rubber and an acoustic sensor chip were analyzed. The displacement of the acoustic sensor chip is loaded with force. The results of static analysis and harmonic analysis show that while increasing Young's modulus of anti-chock rubber, the first five natural frequencies of the package body also increases. Yet the displacement of the acoustic sensor chip around the resonant frequency decreases. The results of static and transient analysis show that the displacement of the acoustic sensor chip decreases with the increase of Young's modulus of anti-chock rubber being loaded with either transient force or static force at the bottom of the combination of rubber and acoustic sensor chip.

  16. MEMS Direct Chip Attach Packaging Methodologies and Apparatuses for Harsh Environments

    Science.gov (United States)

    Okojie, Robert S. (Inventor)

    2009-01-01

    Methods of bulk manufacturing high temperature sensor subassembly packages are disclosed and claimed. Sensors are sandwiched between a top cover and a bottom cover so as to enable the peripheries of the top covers, sensors and bottom covers to be sealed and bound securely together are disclosed and claimed. Sensors are placed on the bottom covers leaving the periphery of the bottom cover exposed. Likewise, top covers are placed on the sensors leaving the periphery of the sensor exposed. Individual sensor sub-assemblies are inserted into final packaging elements which are also disclosed and claimed. Methods of directly attaching wires or pins to contact pads on the sensors are disclosed and claimed. Sensors, such as pressure sensors and accelerometers, and headers made out of silicon carbide and aluminum nitride are disclosed and claimed. Reference cavities are formed in some embodiments disclosed and claimed herein where top covers are not employed.

  17. Wafer-level chip-scale packaging analog and power semiconductor applications

    CERN Document Server

    Qu, Shichun

    2015-01-01

    This book presents a state-of-art and in-depth overview in analog and power WLCSP design, material characterization, reliability, and modeling. Recent advances in analog and power electronic WLCSP packaging are presented based on the development of analog technology and power device integration. The book covers in detail how advances in semiconductor content, analog and power advanced WLCSP design, assembly, materials, and reliability have co-enabled significant advances in fan-in and fan-out with redistributed layer (RDL) of analog and power device capability during recent years. Along with new analog and power WLCSP development, the role of modeling is a key to assure successful package design. An overview of the analog and power WLCSP modeling and typical thermal, electrical, and stress modeling methodologies is also provided. This book also: ·         Covers the development of wafer-level power discrete packaging with regular wafer-level design concepts and directly bumping technology ·    �...

  18. Packaging a free-space intra-chip optical interconnect module: Monte Carlo tolerance study and assembly results

    Science.gov (United States)

    Vervaeke, Michael; Lahti, Markku; Karpinnen, Mikko; Debaes, Christof; Volckaerts, Bart; Karioja, Pentti; Thienpont, Hugo

    2006-04-01

    In this paper we give an overview of the fabrication and assembly induced performance degradation of an intra-multi-chip-module free-space optical interconnect, integrating micro-lenses and a deflection prism above a dense opto-electronic chip. The proposed component is used to demonstrate the capabilities of an accurate micro-optical rapid prototype technique, namely the Deep Proton Writing (DPW). To evaluate the accuracy of DPW and to assess whether our assembly scheme will provide us with a reasonable process yield, we have built a simulation framework combining mechanical Monte Carlo analysis with optical simulations. Both the technological requirements to ensure a high process yield, and the specifications of our in-house DPW technology are discussed. Therefore, we first conduct a sensitivity analysis and we subsequently simulate the effect of combined errors using a Monte Carlo simulation. We are able to investigate the effect of a technology accuracy enhancement on the fabrication and assembly yield by scaling the standard deviation of the errors proportionally to each sensitivity interval. We estimate that 40% of the systems fabricated with DPW will show an optical transmission efficiency above -4.32 dB, which is -3 dB below the theoretical obtainable value. We also discuss our efforts to implement an opto-mechanical Monte Carlo simulator. It enables us to address specific issues not directly related with the micro-optical or DPW components, such as the influence of glueing layers and structures that allow for self-alignment, by combining mechanical tolerancing algorithms with optical simulation software. More in particular we determined that DPW provides ample accuracy to meet the requirements to obtain a high manufacturing yield. Finally, we shortly highlight the basic layout of a completed demonstrator. The adhesive bonding of opto-electronic devices in their package is subject to further improvement to enhance the tilt accuracy of the devices with

  19. All-optical SR flip-flop based on SOA-MZI switches monolithically integrated on a generic InP platform

    Science.gov (United States)

    Pitris, St.; Vagionas, Ch.; Kanellos, G. T.; Kisacik, R.; Tekin, T.; Broeke, R.; Pleros, N.

    2016-03-01

    At the dawning of the exaflop era, High Performance Computers are foreseen to exploit integrated all-optical elements, to overcome the speed limitations imposed by electronic counterparts. Drawing from the well-known Memory Wall limitation, imposing a performance gap between processor and memory speeds, research has focused on developing ultra-fast latching devices and all-optical memory elements capable of delivering buffering and switching functionalities at unprecedented bit-rates. Following the master-slave configuration of electronic Flip-Flops, coupled SOA-MZI based switches have been theoretically investigated to exceed 40 Gb/s operation, provided a short coupling waveguide. However, this flip-flop architecture has been only hybridly integrated with silica-on-silicon integration technology exhibiting a total footprint of 45x12 mm2 and intra-Flip-Flop coupling waveguide of 2.5cm, limited at 5 Gb/s operation. Monolithic integration offers the possibility to fabricate multiple active and passive photonic components on a single chip at a close proximity towards, bearing promises for fast all-optical memories. Here, we present for the first time a monolithically integrated all-optical SR Flip-Flop with coupled master-slave SOA-MZI switches. The photonic chip is integrated on a 6x2 mm2 die as a part of a multi-project wafer run using library based components of a generic InP platform, fiber-pigtailed and fully packaged on a temperature controlled ceramic submount module with electrical contacts. The intra Flip-Flop coupling waveguide is 5 mm long, reducing the total footprint by two orders of magnitude. Successful flip flop functionality is evaluated at 10 Gb/s with clear open eye diagram, achieving error free operation with a power penalty of 4dB.

  20. Finite element modelling for the investigation of edge effect in acoustic micro imaging of microelectronic packages

    Science.gov (United States)

    Shen Lee, Chean; Zhang, Guang-Ming; Harvey, David M.; Ma, Hong-Wei; Braden, Derek R.

    2016-02-01

    In acoustic micro imaging of microelectronic packages, edge effect is often presented as artifacts of C-scan images, which may potentially obscure the detection of defects such as cracks and voids in the solder joints. The cause of edge effect is debatable. In this paper, a 2D finite element model is developed on the basis of acoustic micro imaging of a flip-chip package using a 230 MHz focused transducer to investigate acoustic propagation inside the package in attempt to elucidate the fundamental mechanism that causes the edge effect. A virtual transducer is designed in the finite element model to reduce the coupling fluid domain, and its performance is characterised against the physical transducer specification. The numerical results showed that the under bump metallization (UBM) structure inside the package has a significant impact on the edge effect. Simulated wavefields also showed that the edge effect is mainly attributed to the horizontal scatter, which is observed in the interface of silicon die-to-the outer radius of solder bump. The horizontal scatter occurs even for a flip-chip package without the UBM structure.

  1. Photonic packaging sourcebook fiber-chip coupling for optical components, basic calculations, modules

    CERN Document Server

    Fischer-Hirchert, Ulrich H P

    2015-01-01

    This book serves as a guide on photonic assembly techniques. It provides an overview of today's state-of-the-art technologies for photonic packaging experts and professionals in the field. The text guides the readers to the practical use of optical connectors. It also assists engineers to find a way to an effective and inexpensive set-up for their own needs. In addition, many types of current industrial modules and state-of-the-art applications from single fiber to multi fiber are described in detail. Simulation techniques such as FEM, BPM and ray tracing are explained in depth. Finally, all recent reliability test procedures for datacom and telecom modules are illustrated in combination with related standardization aspects.

  2. GaN-on-Si blue/white LEDs: epitaxy, chip, and package

    Science.gov (United States)

    Qian, Sun; Wei, Yan; Meixin, Feng; Zengcheng, Li; Bo, Feng; Hanmin, Zhao; Hui, Yang

    2016-04-01

    The dream of epitaxially integrating III-nitride semiconductors on large diameter silicon is being fulfilled through the joint R&D efforts of academia and industry, which is driven by the great potential of GaN-on-silicon technology in improving the efficiency yet at a much reduced manufacturing cost for solid state lighting and power electronics. It is very challenging to grow high quality GaN on Si substrates because of the huge mismatch in the coefficient of thermal expansion (CTE) and the large mismatch in lattice constant between GaN and silicon, often causing a micro-crack network and a high density of threading dislocations (TDs) in the GaN film. Al-composition graded AlGaN/AlN buffer layers have been utilized to not only build up a compressive strain during the high temperature growth for compensating the tensile stress generated during the cool down, but also filter out the TDs to achieve crack-free high-quality n-GaN film on Si substrates, with an X-ray rocking curve linewidth below 300 arcsec for both (0002) and (101¯2) diffractions. Upon the GaN-on-Si templates, prior to the deposition of p-AlGaN and p-GaN layers, high quality InGaN/GaN multiple quantum wells (MQWs) are overgrown with well-engineered V-defects intentionally incorporated to shield the TDs as non-radiative recombination centers and to enhance the hole injection into the MQWs through the via-like structures. The as-grown GaN-on-Si LED wafers are processed into vertical structure thin film LED chips with a reflective p-electrode and the N-face surface roughened after the removal of the epitaxial Si(111) substrates, to enhance the light extraction efficiency. We have commercialized GaN-on-Si LEDs with an average efficacy of 150-160 lm/W for 1mm2 LED chips at an injection current of 350 mA, which have passed the 10000-h LM80 reliability test. The as-produced GaN-on-Si LEDs featured with a single-side uniform emission and a nearly Lambertian distribution can adopt the wafer-level phosphor

  3. Heat Transfer Characteristics in High Power LED Packaging

    Directory of Open Access Journals (Sweden)

    Chi-Hung Chung

    2014-03-01

    Full Text Available This study uses the T3Ster transient thermal resistance measuring device to investigate the effects to heat transfer performances from different LED crystal grains, packaging methods and heat-sink substrates through the experimental method. The experimental parameters are six different types of LED modules that are made alternatively with the crystal grain structure, the die attach method and the carrying substrate. The crystal grain structure includes the lateral type, flip chip type and vertical type. The die attach method includes silver paste and the eutectic structure. The carrying substrates are aluminum oxide (Alumina and aluminum nitride (AIN ceramic substrates and metal core PCB (MCPCB. The experimental results show that, under the conditions of the same crystal grain and die attach method, the thermal resistance values for the AIN substrate and the Alumina substrate are 2.1K/W and 5.1K/W, respectively and the total thermal resistance values are 7.3K/W and 10.8K/W. Compared to the Alumina substrate, the AIN substrate can effectively lower the total thermal resistance value by 32.4%. This is because the heat transfer coefficient of the AIN substrate is higher than that of the Alumina substrate, thus effectively increasing its thermal conductivity. In addition, under the conditions of the same crystal grain and the same substrate, the packaging methods are using silver paste and the eutectic structure for die attach. Their thermal resistance values are 5.7K/W and 2.7K/W, respectively, with a variance of 3K/W. Comparisons of the crystal grain structure show that the thermal resistance for the flip chip type is lower than that of the traditional lateral type by 0.9K/W. This is because the light emitting layer of the flip chip crystal grain is closer to the heat-sink substrate, shortening the heat dissipation route, and thus lowering the thermal resistance value. For the total thermal resistance, the crystal grain structure has a lesser

  4. A Flip-Chip AlGaInP LED with GaN/Sapphire Transparent Substrate Fabricated by Direct Wafer Bonding

    Institute of Scientific and Technical Information of China (English)

    LIANG Ting; GUO Xia; GUAN Bao-Lu; GUO Jing; GU Xiao-Ling; LIN Qiao-Ming; SHEN Guang-Di

    2007-01-01

    A red-light AlGaInP light emitting diode(LED)is fabricated by,using direct wafer bonding technology.Taking N-GaN wafer as the transparent substrate,the red-light LED is flip-chiped onto a structured silicon submount.Electronic luminance(EL)test reveals that the luminance flux is 130% higher than that of the conventional LED made from the same LED wafer.Current-voltage(Ⅰ-Ⅴ)measurement indicates that the bonding processes do not impact the electrical property of AlGaInP LED in the small voltage region (V<1.5V).In the large voltage region (V>1.5 V),the Ⅰ-Ⅴ characteristic exhibits space-charge-limited currents characteristic due to the p-GaAs/n-GaN bonding interface.

  5. MEMS Devices Packaging Technology%MEMS器件封装技术

    Institute of Scientific and Technical Information of China (English)

    袁永举; 王静

    2012-01-01

    综述了微电子机械系统(MEMS)封装主流技术,包括芯片级封装、器件级封装和系统及封装技术进行了。重点介绍了圆片级键合、倒装焊等封装技术。并对MEMS封装的技术瓶颈进行了分析。%The technologies of MEMS packaging are introduced, including three promising technologies: Wafer Level Packaging, Device Level, System Level Packaging. And the emphasis about using wafer level bonding, flip chip bonding technology. Then several reliability issues in MEMS packaging are pointed out, and a forecast is given for its future trends.

  6. Miniature stick-packaging--an industrial technology for pre-storage and release of reagents in lab-on-a-chip systems.

    Science.gov (United States)

    van Oordt, Thomas; Barb, Yannick; Smetana, Jan; Zengerle, Roland; von Stetten, Felix

    2013-08-01

    Stick-packaging of goods in tubular-shaped composite-foil pouches has become a popular technology for food and drug packaging. We miniaturized stick-packaging for use in lab-on-a-chip (LOAC) systems to pre-store and on-demand release the liquid and dry reagents in a volume range of 80-500 μl. An integrated frangible seal enables the pressure-controlled release of reagents and simplifies the layout of LOAC systems, thereby making the package a functional microfluidic release unit. The frangible seal is adjusted to defined burst pressures ranging from 20 to 140 kPa. The applied ultrasonic welding process allows the packaging of temperature sensitive reagents. Stick-packs have been successfully tested applying recovery tests (where 99% (STDV = 1%) of 250 μl pre-stored liquid is released), long-term storage tests (where there is loss of only simulated 2 years) and air transport simulation tests. The developed technology enables the storage of a combination of liquid and dry reagents. It is a scalable technology suitable for rapid prototyping and low-cost mass production.

  7. Vacuum packaging research of optically readable infrared imaging chip%光读出红外成像芯片真空封装研究

    Institute of Scientific and Technical Information of China (English)

    张云胜; 冯飞; 魏旭东; 戈肖鸿; 王跃林

    2015-01-01

    为解决光读出红外成像焦平面阵列器件的真空封装,提出了一种新颖的真空封装方法。该封装结构由可见光窗口、硅垫片和红外窗口三部分构成。硅垫片和可见光窗口(玻璃)通过阳极键合形成封装腔体,用于放置芯片;红外窗口不仅选择性增透8~14μm波段的红外辐射,且作为封装盖板;封装腔体和红外窗口在真空室内通过焊料键合完成真空封装。该封装结构通过了气密检测,并测试得到了200℃电烙铁热像图。%A novel vacuum packaging method is proposed for vacuum packaging optically readable infrared imaging focal plane array( ORIRFPA)device. The vacuum packaging structure is made up of three parts,a visible light window,a silicon spacer,and an infrared window. The silicon spacer is bonded to visible light window-glass using anodic bonding to form packaging cavity,for chip placement;infrared window is not only used to selectively transmit infrared radiation ranges from 8μm to 14μm,but also is used as packaging cover board;packaging cavity is solder bonded to infrared window in vacuum chamber. Then the packaging structure passes air tightness test,and thermal images of soldering iron at temperature 200℃ are test and obtained.

  8. SU-8 cantilever chip interconnection

    DEFF Research Database (Denmark)

    Johansson, Alicia Charlotte; Janting, Jakob; Schultz, Peter;

    2006-01-01

    the electrodes on the SU-8 chip to a printed circuit board. Here, we present two different methods of electrically connecting an SU-8 chip, which contains a microfluidic network and free-hanging mechanical parts. The tested electrical interconnection techniques are flip chip bonding using underfill or flip chip...... bonding using an anisotropic conductive film (ACF). These are both widely used in the Si industry and might also be used for the large scale interconnection of SU-8 chips. The SU-8 chip, to which the interconnections are made, has a microfluidic channel with integrated micrometer-sized cantilevers...... that can be used for label-free biochemical detection. All the bonding tests are compared with results obtained using similar Si chips. It is found that it is significantly more complicated to interconnect SU-8 than Si cantilever chips primarily due to the softness of SU-8....

  9. Flipped Classroom Approach

    Directory of Open Access Journals (Sweden)

    Fezile Ozdamli

    2016-07-01

    Full Text Available Flipped classroom is an active, student-centered approach that was formed to increase the quality of period within class. Generally this approach whose applications are done mostly in Physical Sciences, also attracts the attention of educators and researchers in different disciplines recently. Flipped classroom learning which wide-spreads rapidly in the world, is not well recognized in our country. That is why the aim of study is to attract attention to its potential in education field and provide to make it recognize more by educators and researchers. With this aim, in the study what flipped classroom approach is, flipped classroom technology models, its advantages and limitations were explained.

  10. Flipping Freshman Mathematics

    Science.gov (United States)

    Zack, Laurie; Fuselier, Jenny; Graham-Squire, Adam; Lamb, Ron; O'Hara, Karen

    2015-01-01

    Our study compared a flipped class with a standard lecture class in four introductory courses: finite mathematics, precalculus, business calculus, and calculus 1. The flipped sections watched video lectures outside of class and spent time in class actively working on problems. The traditional sections had lectures in class and did homework outside…

  11. The flipped classroom

    DEFF Research Database (Denmark)

    Triantafyllou, Evangelia

    2015-01-01

    class time is devoted to clarifications and application of this knowledge. The hypothesis is that there could be deep and creative discussions when teacher and students physically meet. This paper presents design considerations for flipped classrooms, and discusses how Moodle can facilitate...... with a discussion of the opportunities and challenges when implementing the flipped model in a virtual learning environment (VLE) like Moodle....

  12. Flipping Freshman Mathematics

    Science.gov (United States)

    Zack, Laurie; Fuselier, Jenny; Graham-Squire, Adam; Lamb, Ron; O'Hara, Karen

    2015-01-01

    Our study compared a flipped class with a standard lecture class in four introductory courses: finite mathematics, precalculus, business calculus, and calculus 1. The flipped sections watched video lectures outside of class and spent time in class actively working on problems. The traditional sections had lectures in class and did homework outside…

  13. Metallization and packaging of compound semiconductor devices at Sandia National Laboratories

    Energy Technology Data Exchange (ETDEWEB)

    Seigal, P.K.; Armendariz, M.G.; Rieger, D.J.; Lear, K.L.; Sullivan, C.T.

    1996-11-01

    Recent advances in compound semiconductor technology utilize a variety of metal thin films fabricated by thermal and electron-beam evaporation, and electroplating. An overview of metal processes used by Sandia`s Compound Semiconductor Research Laboratory is presented. Descriptions of electrical n-type and p-type ohmic contact alloys, interconnect metal, and metal layers specifically included for packaging requirements are addressed. Several illustrations of devices incorporating gold plated air bridges are included. ``Back-end`` processes such as flip-chip under bump metallurgy with fluxless solder reflow and plated solder processes are mentioned as current research areas.

  14. Study of Thermally Enhanced 2.5D Packages with Multi-chips Molded on Silicon Interposer

    Science.gov (United States)

    Zhang, H. Y.; Zhang, X. W.

    2015-07-01

    The 2.5D package with distributed vias on silicon interposer has received great attention due to its potential for heterogeneous integration. The overmolded 2.5D package protects the silicon die and interposer from environmental damage, which, on the other hand, induces undesirable thermal resistance due to low thermal conductivity of the molding compound. In this paper, a thermally enhanced 2.5D package with exposed die is proposed, fabricated and examined from the thermal enhancement viewpoint. The high power thermal test die was first assembled on a silicon interposer with through silicon vias and connected to the substrate, which was followed by the overmolding and back-grinding processes to form the partially molded (PM) package with exposed die for direct heat sink attachments. Experiments were conducted to examine the thermal performance under different thermal conditions. Under natural convection without thermal enhancement, there was no performance difference between the PM package and the overmolded package. However, when the package top was mounted with a thermally enhanced structure such as a pin fin heat sink, the thermal resistance of PM package was significantly reduced. The advantage was more prominent with the attachment of a high performance liquid cooling heat sink. Thermal simulation models were also constructed to examine the thermal performances under different test conditions, and the realistic thermal interface resistance of 0.5 Kcm2/W was estimated based on the package warpage. The computed thermal resistances agreed with measurement results.

  15. Wafer-level vacuum/hermetic packaging technologies for MEMS

    Science.gov (United States)

    Lee, Sang-Hyun; Mitchell, Jay; Welch, Warren; Lee, Sangwoo; Najafi, Khalil

    2010-02-01

    An overview of wafer-level packaging technologies developed at the University of Michigan is presented. Two sets of packaging technologies are discussed: (i) a low temperature wafer-level packaging processes for vacuum/hermeticity sealing, and (ii) an environmentally resistant packaging (ERP) technology for thermal and mechanical control as well as vacuum packaging. The low temperature wafer-level encapsulation processes are implemented using solder bond rings which are first patterned on a cap wafer and then mated with a device wafer in order to encircle and encapsulate the device at temperatures ranging from 200 to 390 °C. Vacuum levels below 10 mTorr were achieved with yields in an optimized process of better than 90%. Pressures were monitored for more than 4 years yielding important information on reliability and process control. The ERP adopts an environment isolation platform in the packaging substrate. The isolation platform is designed to provide low power oven-control, vibration isolation and shock protection. It involves batch flip-chip assembly of a MEMS device onto the isolation platform wafer. The MEMS device and isolation structure are encapsulated at the wafer-level by another substrate with vertical feedthroughs for vacuum/hermetic sealing and electrical signal connections. This technology was developed for high performance gyroscopes, but can be applied to any type of MEMS device.

  16. Flipped Learning in the Workplace

    Science.gov (United States)

    Nederveld, Allison; Berge, Zane L.

    2015-01-01

    Purpose: The purpose of this paper is to serve as a summary of resources on flipped learning for workplace learning professionals. A recent buzzword in the training world is "flipped". Flipped learning and the flipped classroom are hot topics that have emerged in K-12 education, made their way to the university and are now being noticed…

  17. Fundamental study of microelectronic chip response under laser ultrasonic-interferometric inspection using C-scan method

    Science.gov (United States)

    Yang, Lei; Gong, Jie; Ume, I. Charles

    2014-02-01

    In modern surface mount packaging technologies, such as flip chips, chip scale packages, and ball grid arrays(BGA), chips are attached to the substrates/printed wiring board (PWB) using solder bump interconnections. The quality of solder bumps between the chips and the substrate/board is difficult to inspect. Laser ultrasonic-interferometric technique was proved to be a promising approach for solder bump inspection because of its noncontact and nondestructive characteristics. Different indicators extracted from received signals have been used to predict the potential defects, such as correlation coefficient, error ratio, frequency shifting, etc. However, the fundamental understanding of the chip behavior under laser ultrasonic inspection is still missing. Specifically, it is not sure whether the laser interferometer detected out-of-plane displacements were due to wave propagation or structural vibration when the chip was excited by pulsed laser. Plus, it is found that the received signals are chip dependent. Both challenges impede the interpretation of acquired signals. In this paper, a C-scan method was proposed to study the underlying phenomenon during laser ultrasonic inspection. The full chip was inspected. The response of the chip under laser excitation was visualized in a movie resulted from acquired signals. Specifically, a BGA chip was investigated to demonstrate the effectiveness of this method. By characterizing signals using discrete wavelet transform(DWT), both ultrasonic wave propagation and vibration were observed. Separation of them was successfully achieved using ideal band-pass filter and visualized in resultant movies, too. The observed ultrasonic waves were characterized and their respective speeds were measured by applying 2-D FFT. The C-scan method, combined with different digital signal processing techniques, was proved to be an very effective methodology to learn the behavior of chips under laser excitation. This general procedure can be

  18. Using a Flipped Spoon to Decrease Packing in Children with Feeding Disorders

    Science.gov (United States)

    Volkert, Valerie M.; Vaz, Petula C. M.; Piazza, Cathleen C.; Frese, Jana; Barnett, Lara

    2011-01-01

    We evaluated the effects of redistribution and swallow facilitation with a flipped spoon on packing in 2 children with a feeding disorder. For both participants, packing decreased when we implemented the flipped spoon treatment package. Mechanisms responsible for behavior change and areas of future research are discussed. (Contains 1 figure.)

  19. The flipped classroom

    DEFF Research Database (Denmark)

    Triantafyllou, Evangelia

    2015-01-01

    One of the novel ideas in teaching that heavily relies on current technology is the “flipped classroom” approach. In a flipped classroom the traditional lecture and homework sessions are inverted. Students are provided with online material in order to gain necessary knowledge before class, while...... class time is devoted to clarifications and application of this knowledge. The hypothesis is that there could be deep and creative discussions when teacher and students physically meet. This paper presents design considerations for flipped classrooms, and discusses how Moodle can facilitate...... communication and information sharing in such classrooms. Furthermore, it provides guidelines for supporting out-of-class instruction in the flipped model by using quizzes and feedback in Moodle, and comments on the potential to follow student use of resources by using Moodle reports. This paper concludes...

  20. Flip Video for Dummies

    CERN Document Server

    Hutsko, Joe

    2010-01-01

    The full-color guide to shooting great video with the Flip Video camera. The inexpensive Flip Video camera is currently one of the hottest must-have gadgets. It's portable and connects easily to any computer to transfer video you shoot onto your PC or Mac. Although the Flip Video camera comes with a quick-start guide, it lacks a how-to manual, and this full-color book fills that void! Packed with full-color screen shots throughout, Flip Video For Dummies shows you how to shoot the best possible footage in a variety of situations. You'll learn how to transfer video to your computer and then edi

  1. Nutrition labelling, marketing techniques, nutrition claims and health claims on chip and biscuit packages from sixteen countries

    National Research Council Canada - National Science Library

    Mayhew, Alexandra J; Lock, Karen; Kelishadi, Roya; Swaminathan, Sumathi; Marcilio, Claudia S; Iqbal, Romaina; Dehghan, Mahshid; Yusuf, Salim; Chow, Clara K

    2016-01-01

    Food packages were objectively assessed to explore differences in nutrition labelling, selected promotional marketing techniques and health and nutrition claims between countries, in comparison to national regulations. Cross-sectional...

  2. The extended Beer-Lambert theory for ray tracing modeling of LED chip-scaled packaging application with multiple luminescence materials

    Science.gov (United States)

    Yuan, Cadmus C. A.

    2015-12-01

    Optical ray tracing modeling applied Beer-Lambert method in the single luminescence material system to model the white light pattern from blue LED light source. This paper extends such algorithm to a mixed multiple luminescence material system by introducing the equivalent excitation and emission spectrum of individual luminescence materials. The quantum efficiency numbers of individual material and self-absorption of the multiple luminescence material system are considered as well. By this combination, researchers are able to model the luminescence characteristics of LED chip-scaled packaging (CSP), which provides simple process steps and the freedom of the luminescence material geometrical dimension. The method will be first validated by the experimental results. Afterward, a further parametric investigation has been then conducted.

  3. Co-Design Method and Wafer-Level Packaging Technique of Thin-Film Flexible Antenna and Silicon CMOS Rectifier Chips for Wireless-Powered Neural Interface Systems.

    Science.gov (United States)

    Okabe, Kenji; Jeewan, Horagodage Prabhath; Yamagiwa, Shota; Kawano, Takeshi; Ishida, Makoto; Akita, Ippei

    2015-12-16

    In this paper, a co-design method and a wafer-level packaging technique of a flexible antenna and a CMOS rectifier chip for use in a small-sized implantable system on the brain surface are proposed. The proposed co-design method optimizes the system architecture, and can help avoid the use of external matching components, resulting in the realization of a small-size system. In addition, the technique employed to assemble a silicon large-scale integration (LSI) chip on the very thin parylene film (5 μm) enables the integration of the rectifier circuits and the flexible antenna (rectenna). In the demonstration of wireless power transmission (WPT), the fabricated flexible rectenna achieved a maximum efficiency of 0.497% with a distance of 3 cm between antennas. In addition, WPT with radio waves allows a misalignment of 185% against antenna size, implying that the misalignment has a less effect on the WPT characteristics compared with electromagnetic induction.

  4. Co-Design Method and Wafer-Level Packaging Technique of Thin-Film Flexible Antenna and Silicon CMOS Rectifier Chips for Wireless-Powered Neural Interface Systems

    Directory of Open Access Journals (Sweden)

    Kenji Okabe

    2015-12-01

    Full Text Available In this paper, a co-design method and a wafer-level packaging technique of a flexible antenna and a CMOS rectifier chip for use in a small-sized implantable system on the brain surface are proposed. The proposed co-design method optimizes the system architecture, and can help avoid the use of external matching components, resulting in the realization of a small-size system. In addition, the technique employed to assemble a silicon large-scale integration (LSI chip on the very thin parylene film (5 μm enables the integration of the rectifier circuits and the flexible antenna (rectenna. In the demonstration of wireless power transmission (WPT, the fabricated flexible rectenna achieved a maximum efficiency of 0.497% with a distance of 3 cm between antennas. In addition, WPT with radio waves allows a misalignment of 185% against antenna size, implying that the misalignment has a less effect on the WPT characteristics compared with electromagnetic induction.

  5. FLIPPED LEARNING: PRACTICAL ASPECTS

    Directory of Open Access Journals (Sweden)

    Olena Kuzminska

    2016-03-01

    Full Text Available The article is devoted to issues of implementation of the flipped learning technology in the practice of higher education institutions. The article defines the principles of technology and a model of the educational process, it notes the need to establish an information support system. The article defines online platforms and resources; it describes recommendations for the design of electronic training courses and organization of the students in the process of implementing the proposed model, as well as tools for assessing its effectiveness. The article provides a description of flipped learning implementation scenario and formulates suggestions regarding the use of this model as a mechanism to improve the efficiency of the learning process in the ICT-rich environment of high school: use of learning management systems (LMS and personal learning environments (PLE of participants in a learning process. The article provides an example of implementation of the flipped learning model as a part of the Information Technologies course in the National University of Life and Environmental Sciences of Ukraine (NULES. The article gives examples of tasks, resources and services, results of students’ research activity, as well as an example of the personal learning network, established in the course of implementation of the flipped learning model and elements of digital student portfolios. It presents the results of the monitoring of learning activities and students’ feedback. The author describes cautions against the mass introduction of the flipped learning model without monitoring of readiness of the participants of the educational process for its implementation

  6. Nursing education: Flipping the classroom.

    Science.gov (United States)

    Hessler, Karen L

    2016-02-18

    This article will introduce the innovative educational concept of the "flipped classroom." How to implement the flipped learning model will be addressed within the framework of The Intentional Instruction Environment Model.

  7. Wafer-level packaging and laser bonding as an approach for silicon-into-lab-on-chip integration

    Science.gov (United States)

    Brettschneider, T.; Dorrer, C.; Bründel, M.; Zengerle, R.; Daub, M.

    2013-05-01

    A novel approach for the integration of silicon biosensors into microfluidics is presented. Our approach is based on wafer-level packaging of the silicon die and a laser-bonding process of the resulting mold package into a polymer-multilayer stack. The introduction of a flexible and 40 μm thin hot melt foil as an intermediate layer enables laser bonding between materials with different melting temperatures, where standard laser welding processes cannot be employed. All process steps are suitable for mass production, e.g. the approach does not involve any dispensing steps for glue or underfiller. The integration approach was demonstrated and evaluated regarding process technology by wafer-level redistribution of daisy chain silicon dies representing a generic biosensor. Electrical connection was successfully established and laser-bonding tensile strength of 5.7 N mm-2 and burst pressure of 587 kPa at a temperature of 100 °C were achieved for the new material combination. The feasibility of the complete packaging approach was shown by the fabrication of a microfluidic flow cell with embedded mold package.

  8. Laser-assisted ultrathin bare die packaging: a route to a new class of microelectronic devices

    Science.gov (United States)

    Marinov, Val R.; Swenson, Orven; Atanasov, Yuriy; Schneck, Nathan

    2013-03-01

    Ultrathin flip-chip semiconductor die packaging on paper substrates is an enabling technology for a variety of extremely low-cost electronic devices with huge market potential such as RFID smart forms, smart labels, smart tickets, banknotes, security documents, etc. Highly flexible and imperceptible dice are possible only at a thickness of less than 50 μm, preferably down to 10-20 μm or less. Several cents per die cost is achievable only if the die size is technology today can package such die onto a flexible substrate at low cost and high rate. The laser-enabled advanced packaging (LEAP) technology has been developed at the Center for Nanoscale Science and Engineering, North Dakota State University in Fargo, North Dakota, to accomplish this objective. Presented are results using LEAP to assemble dice with various thicknesses, including 350 μm/side dice as thin as 20 μm and less. To the best of our knowledge, this is the first report of using a laser to package conventional silicon dice with such small size and thickness. LEAP-packaged RFID-enabled paper for financial and security applications is also demonstrated. The cost of packaging using LEAP is lower compared to the conventional pick-and-place methods while the rate of packaging is much higher and independent of the die size.

  9. The Summarizing of SAW Packaging Technology%SAW器件封装技术概述

    Institute of Scientific and Technical Information of China (English)

    杨渊华; 王保卫

    2007-01-01

    小型化和多功能化是SAW器件发展的主要动力.文章回顾了SAW器件封装的发展历史,介绍了金属封装、塑料封装、SMD封装各自的特点,详述了芯片倒装技术及芯片尺寸SAW封装(Chip Sized SAW Package,CSSP)技术,将通用芯片倒装技术(Flip Chip Bonding,FCB)和SAW封装的特点结合,使封装尺寸减小到极限.然后对今后的复合封装进行了展望.

  10. Flipping the Classroom

    Science.gov (United States)

    Riendeau, Diane

    2012-11-01

    A recent trend in education is the ``flipped'' or ``reversed'' classroom. In this educational model, students view videos of the lectures as their homework and class time is used for activities and solving problems that might have been assigned as homework in a traditional classroom. Although far from an expert on flipping the classroom, I can see some merit in the idea. When students watch the videos at home, they can start and restart the lecture as often as they like. The lectures are also available for review before the exam. Class time can be used for higher-order questioning, experiments, and problem solving.

  11. System-in-package LTCC platform for 3D RF to millimeter wave

    Science.gov (United States)

    Vähä-Heikkilä, T.; Lahti, M.

    2011-04-01

    This presentation shows recent trends and results in 3D Low Temperature Co-Fired Ceramics (LTCC) modules in applications from RF to millimeter waves. The system-in-package LTCC platform is a true three dimensional module technology. LTCC is a lightweight multi-layer technology having typically 6-20 ceramic layers and metallizations between. The metallization levels i.e different metal layers can be patterned and connected together with metal vias. Passive devices can also be fabricated on LTCC while active devices and other chips are connected with flip-chip, wire bonding or soldering. In addition to passives directly fabricated to LTCC, several different technologies/ chips can be hybrid integrated to the same module. LTCC platform is also well suited for the realization of antenna arrays for microwave and millimeter wave applications. Potential applications are ranging from short range communications to space and radars. VTT has designed, fabricated and characterized microwave and millimeter wave packages for Radio Frequency (RF) Micro Electro Mechanical Systems (MEMS) as well as active devices. Also, several types of system-in-package modules have been realized containing hybrid integrated CMOS and GaAs MMICs and antenna arrays.

  12. 'Flipping' the Classroom.

    Science.gov (United States)

    Billings, Diane M

    2016-09-01

    This article is one in a series on the roles of adjunct clinical faculty and preceptors, who teach nursing students and new graduates to apply knowledge in clinical settings. This article describes the benefits and challenges of using a "flipped" classroom to promote active engagement among learners and more meaningful interaction between learners and educators.

  13. Flipping the Classroom Revisited

    Science.gov (United States)

    Riendeau, Diane

    2013-02-01

    I received many emails following the first column on flipping the classroom. Many of my local colleagues also approached me at our physics alliance, Physics Northwest. Teachers are very interested in this new pedagogy. As I result, I wanted to share some more videos to inspire you.

  14. Packaging Challenges and Solutions for Multi-Stack Die Applications%多层芯片应用中的封装挑战和解决方案

    Institute of Scientific and Technical Information of China (English)

    BobChylak; IvyWeiQin

    2003-01-01

    The continuous growth of stacked die packages is resulting from the technology's ability to effectively increase the functionality and capacity of electronic devices within the same footprint as a single chip. The increased utilization of stacked die packages in cell phone and other consumer products drives technologies that enable multiple die stacks within a given package dimension.This paper reviews the technology requirements and challenges for stacked die packages. Foremost among these is meeting package height requirements. For example, a standard package height is 1.2 mm for a single die package. For stacked die packages, two or more die need to fit in the same area. That means every dimension in the package has to decrease, including the die thickness, the mold cap thickness,the bond line thickness and the wire bond loop profile. The technology enablers for stacked die packages include wafer thinning, thin die attachment, low profile wire bonding, bonding to unsupported edges and low sweep molding.This article focuses on stacked die interconnect requirements. Technologies including forward ball bonding, reverse ball bonding and stud bumping for flip chip applications are reviewed, and the advantages and trade-offs are discussed. Developments in ball bonder capabilities to meet the challenges of stacked die packages are presented, such as ultra-low loop shapes, long wire spans and overhang bonding. Packaging design guidelines to maximize productivity and assembly yield are proposed to address the critical design and assembly issues such as maximum die over hang length at different die thickness, wire bond parameter optimization to minimize yield loss due to wire shorts, die crack and other wire bonding defects.

  15. All-optical flip-flop based on vertical cavity semiconductor optical amplifiers.

    Science.gov (United States)

    Song, Deqiang; Gauss, Veronica; Zhang, Haijiang; Gross, Matthias; Wen, Pengyue; Esener, Sadik

    2007-10-15

    We report the operation of an all-optical set-reset (SR) flip-flop based on vertical cavity semiconductor optical amplifiers (VCSOAs). This flip-flop is cascadable, has low optical switching power (~10 microW), and has the potential to be integrated on a small footprint (~100 microm(2)). The flip-flop is composed of two cross-coupled electrically pumped VCSOA inverters and uses the principles of cross-gain modulation, polarization gain anisotropy, and highly nonlinear gain characteristics to achieve flip-flop functionality. We believe that, when integrated on chip, this type of all-optical flip-flop opens new prospects for implementing all-optical fast memories and timing regeneration circuits.

  16. Microstructural Evolution of SAC305 Solder Joints in Wafer Level Chip-Scale Packaging (WLCSP) with Continuous and Interrupted Accelerated Thermal Cycling

    Science.gov (United States)

    Zhou, Quan; Zhou, Bite; Lee, Tae-Kyu; Bieler, Thomas

    2016-06-01

    Four high-strain design wafer level chip scale packages were given accelerated thermal cycling with a 10°C/min ramp rate and 10 min hold times between 0°C and 100°C to examine the effects of continuous and interrupted thermal cycling on the number of cycles to failure. The interruptions given two of the samples were the result of periodic examinations using electron backscattered pattern mapping, leading to room temperature aging of 30 days-2.5 years after increments of about 100 cycles at several stages of the cycling history. The continuous thermal cycling resulted in solder joints with a much larger degree of recrystallization, whereas the interrupted thermal cycling tests led to much less recrystallization, which was more localized near the package side, and the crack was more localized near the interface and had less branching. The failure mode for both conditions was still the same, with cracks nucleating along the high angle grain boundaries formed during recrystallization. In conditions where there were few recrystallized grains, recovery led to formation of subgrains that strengthened the solder, and the higher strength led to a larger driving force for crack growth through the solder, leading to failure after less than half of the cycles in the continuous accelerated thermal cycling condition. This work shows that there is a critical point where sufficient strain energy accumulation will trigger recrystallization, but this point depends on the rate of strain accumulation in each cycle and various recovery processes, which further depends on local crystal orientations, stress state evolution, and specific activated slip and twinning systems.

  17. Thermal simulation for the chip model based on RCP package%基于RCP封装的芯片模型电热模拟

    Institute of Scientific and Technical Information of China (English)

    张路

    2015-01-01

    基于集成电路重分布封装技术(redistributed chip packaging,RCP)的发展,通过提取芯片封装体的具体参数,建立并优化了RCP芯片的热学模型.采用有限元的方法计算了该模型在一定热耗散功率下,施加不同风速条件时的温度分布情况,结果表明:强制对流条件的施加显著增强了RCP芯片封装体的散热能力,4m/s的风速可使其系统热阻降低58%,但是随着风速的增大,其影响不断减弱.所得出的具体风速与芯片结温的关系,可为RCP封装技术的散热设计提供有价值的参考.

  18. Flipped Classroom, active Learning?

    DEFF Research Database (Denmark)

    Andersen, Thomas Dyreborg; Levinsen, Henrik; Philipps, Morten

    2015-01-01

    Action research is conducted in three physics classes over a period of eighteen weeks with the aim of studying the effect of flipped classroom on the pupils agency and learning processes. The hypothesis is that flipped classroom teaching will potentially allocate more time to work actively...... with the teaching subject compared to more traditional teaching, where introductions and theoretical monologs conducted by the teacher prevail. In addition it is assumed that the pupils learning processes move towards more independency and metacognitive thinking.   During the study period interventions...... didactic workshop with the involved teachers. One of the demands of the didactic design is to include a video embedded in a formative evaluation sheet produced in Google Drive by the teachers themselves. The didactic analysis of the collected audio and video recordings will be presented at the NOFA 5...

  19. Flip the classroom.

    Science.gov (United States)

    Li, Simon

    2015-11-01

    Given the huge expansion in medical knowledge it is both practical and expedient to make better use of students' time with aids for effective learning, rather than by increasing the length of time it takes to earn a medical degree. Embracing a 'flipped classroom' approach is a way to free-up classroom time to promote active learning through opportunities such as case-based and team-based exercises.

  20. C4NP - Lead Free Flip Chip Solder Bumping Manufacturing and Reliability Data%C4NP-无铅倒装晶片焊凸形成生产工艺与可靠性数据

    Institute of Scientific and Technical Information of China (English)

    2007-01-01

    high-end logic device packaging using 300 mm wafers bumped with C4NP. This includes initial reliability data for C4NP lead free solder bumped devices attached to organic chip carriers. Mold fill data for CSP type dimensions is included. Solder metrology data and yield information for fine pitch applications is summarized. Relevant process equipment technology and the unique requirements to run a high volume manufacturing C4NP process are reviewed. The paper also summarizes the C4NP manufacturing cost model and elaborates on the cost comparison to alternative bumping techniques. The data in this paper is provided by IBM's packaging operations at the Hudson Valley Research Park in East Fishkill, NY and Bromont, Quebec.

  1. Teaching Tip: The Flipped Classroom

    Science.gov (United States)

    Mok, Heng Ngee

    2014-01-01

    The flipped classroom has been gaining popularity in recent years. In theory, flipping the classroom appears sound: passive learning activities such as unidirectional lectures are pushed to outside class hours in the form of videos, and precious class time is spent on active learning activities. Yet the courses for information systems (IS)…

  2. Adventures in Flipping College Algebra

    Science.gov (United States)

    Van Sickle, Jenna

    2015-01-01

    This paper outlines the experience of a university professor who implemented flipped learning in two sections of college algebra courses for two semesters. It details how the courses were flipped, what technology was used, advantages, challenges, and results. It explains what students do outside of class, what they do inside class, and discusses…

  3. Thermal hehavior of Surface Mounted Devices (SMD) packaging

    Science.gov (United States)

    Bloch, Werner; Moeller, Werner

    The thermal behavior of Surface Mounted Devices (SMD) packaging was investigated on an easily variable type. The effect of basic materials, chip carriers, and bonding, soldering, glueing and casting techniques was examined, considering the most important quantities, switching time and power. The test results show that cooling measures in the chip domain, such as chip bonding, chip casting, and chip carrier lining, are especially efficient for short switching times. The basic materials, even with heat sinks, become only important for longer switching times. The chip temperature of a conventional FR4/LCCC packaging was halved by the application of novel packaging materials, without changing the cooling mechanisms and the power.

  4. A flipped 331 model

    CERN Document Server

    Fonseca, Renato M

    2016-01-01

    Models based on the extended $SU(3)_{C}\\times SU(3)_{L}\\times U(1)_{X}$ (331) gauge group usually follow a common pattern: two families of left-handed quarks are placed in anti-triplet representations of the $SU(3)_{L}$ group; the remaining quark family, as well as the left-handed leptons, are assigned to triplets (or vice-versa). In this work we present a flipped 331 model where this scheme is reversed: all three quarks families are in the same representation and it is the lepton families which are discriminated by the gauge symmetry. We discuss fermion masses and mixing, as well as $Z'$ interactions, in a minimal model implementing this idea.

  5. Crystallization by stochastic flips

    Science.gov (United States)

    Bodini, Olivier; Fernique, Thomas; Regnault, Damien

    2010-04-01

    Tilings are often used as a toy model for quasicrystals, with the ground states corresponding to the tilings satisfying some local properties (matching rules). In this context, a challenging problem is to provide a theory for quasicrystals growth. One of the proposed theories is the relaxation process. One assumes that the entropy of a tiling increases with the number of tilings which can be formed with the same tiles, while its energy is proportional to the ratio of satisfied matching rules. Then, by starting from an entropically stabilized tiling at high temperature and by decreasing the temperature, the phason flips which decrease (resp. increase) the energy would become more and more favoured (resp. inhibited). Ideally, the tiling eventually satisfies all the matching rules, and thus shows a quasicrystalline structure. This paper describes a stochastic process inspired by this and discusses its convergence rate.

  6. Practical Quantum Coin Flipping

    CERN Document Server

    Pappa, Anna; Diamanti, Eleni; Kerenidis, Iordanis

    2011-01-01

    In this article we show for the first time that quantum coin flipping with security guarantees that are strictly better than any classical protocol is possible to implement with current technology. Our protocol is tolerant to both loss and noise and takes into account all aspects of an experimental implementation like multi-photon pulses emitted by practical photon sources, channel noise, system loss, detector dark counts and finite quantum efficiency. We calculate the abort probability when both players are honest, as well as the probability of one player forcing his desired outcome. For channel length up to 21 km, we achieve a cheating probability that is better than in any classical protocol. Our protocol is easy to implement using attenuated laser pulses, with no need for entangled photons or any other specific resources.

  7. Advanced organics for electronic substrates and packages

    CERN Document Server

    Fletcher, Andrew E

    1992-01-01

    Advanced Organics for Electronic Substrates and Packages provides information on packaging, which is one of the most technologically intensive activities in the electronics industry. The electronics packaging community has realized that while semiconductor devices continue to be improved upon for performance, cost, and reliability, it is the interconnection or packaging of these devices that will limit the performance of the systems. Technology must develop packaging for transistor chips, with high levels of performance and integration providing cooling, power, and interconnection, and yet pre

  8. MMIC packaging with Waffleline

    Science.gov (United States)

    Perry, R. W.; Ellis, T. T.; Schineller, E. R.

    1990-06-01

    The design principle of Waffleline, a patented MMIC packaging technology, is discussed, and several recent applications are described and illustrated with drawings, diagrams, and photographs. Standard Waffleline is a foil-covered waffle-iron-like grid with dielectric-coated signal and power wires running in the channels and foil-removed holes for mounting prepackaged chips or chip carriers. With spacing of 50 mils between center conductors, this material is applicable at frequencies up to 40 GHz; EHF devices require Waffleline with 25-mil spacing. Applications characterized include a subassembly for a man-transportable SHF satellite-communication terminal, a transmitter driver for a high-power TWT, and a 60-GHz receiver front end (including an integrated monolithic microstrip antenna, a low-noise amplifier, a mixer, and an IF amplifier in a 0.25-inch-thick 1.6-inch-diameter package). The high package density and relatively low cost of Waffleline are emphasized.

  9. Chip, Chip, Hooray!

    Science.gov (United States)

    Kelly, Susan

    2001-01-01

    Presents a science laboratory using different brands of potato chips in which students test their oiliness, size, thickness, saltiness, quality, and cost, then analyze the results to determine the best chip. Gives a brief history of potato chips. (YDS)

  10. Spin flipping a stored polarized proton beam

    Science.gov (United States)

    Caussyn, D. D.; Derbenev, Ya. S.; Ellison, T. J.; Lee, S. Y.; Rinckel, T.; Schwandt, P.; Sperisen, F.; Stephenson, E. J.; von Przewoski, B.; Blinov, B. B.; Chu, C. M.; Courant, E. D.; Crandell, D. A.; Kaufman, W. A.; Krisch, A. D.; Nurushev, T. S.; Phelps, R. A.; Ratner, L. G.; Wong, V. K.; Ohmori, C.

    1994-11-01

    We recently studied the spin flipping of a vertically polarized, stored 139-MeV proton beam. To flip the spin, we induced an rf depolarizing resonance by sweeping our rf solenoid magnet's frequency through the resonance frequency. With multiple spin flips, we found a polarization loss of 0.0000+/-0.0005 per spin flip under the best conditions; this loss increased significantly for small changes in the conditions. Minimizing the depolarization during each spin flip is especially important because frequent spin flipping could significantly reduce the systematic errors in stored polarized-beam experiments.

  11. Microchannel cooling of face down bonded chips

    Science.gov (United States)

    Bernhardt, Anthony F.

    1993-01-01

    Microchannel cooling is applied to flip-chip bonded integrated circuits, in a manner which maintains the advantages of flip-chip bonds, while overcoming the difficulties encountered in cooling the chips. The technique is suited to either multichip integrated circuit boards in a plane, or to stacks of circuit boards in a three dimensional interconnect structure. Integrated circuit chips are mounted on a circuit board using flip-chip or control collapse bonds. A microchannel structure is essentially permanently coupled with the back of the chip. A coolant delivery manifold delivers coolant to the microchannel structure, and a seal consisting of a compressible elastomer is provided between the coolant delivery manifold and the microchannel structure. The integrated circuit chip and microchannel structure are connected together to form a replaceable integrated circuit module which can be easily decoupled from the coolant delivery manifold and the circuit board. The coolant supply manifolds may be disposed between the circuit boards in a stack and coupled to supplies of coolant through a side of the stack.

  12. To Flip or Not to Flip? An Exploratory Study Comparing Student Performance in Calculus I

    Science.gov (United States)

    Schroeder, Larissa B.; McGivney-Burelle, Jean; Xue, Fei

    2015-01-01

    The purpose of this exploratory, mixed-methods study was to compare student performance in flipped and non-flipped sections of Calculus I. The study also examined students' perceptions of the flipping pedagogy. Students in the flipped courses reported spending, on average, an additional 1-2 hours per week outside of class on course content.…

  13. To Flip or Not to Flip? An Exploratory Study Comparing Student Performance in Calculus I

    Science.gov (United States)

    Schroeder, Larissa B.; McGivney-Burelle, Jean; Xue, Fei

    2015-01-01

    The purpose of this exploratory, mixed-methods study was to compare student performance in flipped and non-flipped sections of Calculus I. The study also examined students' perceptions of the flipping pedagogy. Students in the flipped courses reported spending, on average, an additional 1-2 hours per week outside of class on course content.…

  14. Single-transistor-clocked flip-flop

    Science.gov (United States)

    Zhao, Peiyi; Darwish, Tarek; Bayoumi, Magdy

    2005-08-30

    The invention provides a low power, high performance flip-flop. The flip-flop uses only one clocked transistor. The single clocked transistor is shared by the first and second branches of the device. A pulse generator produces a clock pulse to trigger the flip-flop. In one preferred embodiment the device can be made as a static explicit pulsed flip-flop which employs only two clocked transistors.

  15. The Flipped Classroom in Counselor Education

    Science.gov (United States)

    Moran, Kristen; Milsom, Amy

    2015-01-01

    The flipped classroom is proposed as an effective instructional approach in counselor education. An overview of the flipped-classroom approach, including advantages and disadvantages, is provided. A case example illustrates how the flipped classroom can be applied in counselor education. Recommendations for implementing or researching flipped…

  16. A Flipped Classroom Redesign in General Chemistry

    Science.gov (United States)

    Reid, Scott A.

    2016-01-01

    The flipped classroom continues to attract significant attention in higher education. Building upon our recent parallel controlled study of the flipped classroom in a second-term general chemistry course ("J. Chem. Educ.," 2016, 93, 13-23), here we report on a redesign of the flipped course aimed at scaling up total enrollment while…

  17. Flipping a Calculus Class: One Instructor's Experience

    Science.gov (United States)

    Palmer, Katrina

    2015-01-01

    This paper describes one instructor's experiences during a year of flipping four calculus classes. The first exploration attempts to understand student expectations of a math class and their preference towards a flipped classroom. The second examines success of students from a flipped classroom, and the last investigates relationships with student…

  18. A Flipped Classroom Redesign in General Chemistry

    Science.gov (United States)

    Reid, Scott A.

    2016-01-01

    The flipped classroom continues to attract significant attention in higher education. Building upon our recent parallel controlled study of the flipped classroom in a second-term general chemistry course ("J. Chem. Educ.," 2016, 93, 13-23), here we report on a redesign of the flipped course aimed at scaling up total enrollment while…

  19. How To Prepare Effective Flip Charts.

    Science.gov (United States)

    National Audio-Visual Supply, East Rutherford, NJ.

    Designed to help create effective flip chart presentations, this guide contains the basic techniques and helpful hints necessary to produce professional, attention-getting flip charts in a step-by-step procedure format. Five topics are addressed in the guide: (1) eight steps to a successful meeting presentation; (2) advantages of flip chart…

  20. Flip-Flops: Avoid a Flip-Flop Fiasco

    Science.gov (United States)

    ... quality, soft leather. Leather minimizes the potential for blisters and other types of irritation. Do gently bend the flip-flop from end to end, ensuring it bends at the ball of the foot. Shoes of any kind should never fold in half. ...

  1. Using a SPOC to Flip Classroom of Single Chip Computer Tech-nology%基于SPOC的单片机技术翻转课堂教学设计

    Institute of Scientific and Technical Information of China (English)

    丁晨阳; 方小坤

    2016-01-01

    单片机技术是一门实践性要求较高的专业课。为减少课程理论和实践之间的差距,改善学生学习效果,使用SPOC资源对单片机技术课程进行翻转课堂的教学设计,让学生根据自身情况进行学习,并在面对面的课堂中解决实际的单片机控制问题。重新调整后的课程提供给学生一种新的学习探索环境,有利于提高实践能力和创新能力。调查结果表明,大多数学生对这种新的教学方式感到满意。%Single Chip Computer Technology is a practical course. In order to reduce the gap between theory and practice and improve learning eff ect, SPOC is used to fl ip the classroom of Single Chip Computer Technology, so that students are able to study according to their real requirements and solve the actual control problems in a face-to-face classroom. The adjusted course provides students new environment to explore, which is benefi cial to improve their practice and innovation ability. Results show that most of the students are satisfi ed with this teaching mode.

  2. Packaging the MAMA module

    Science.gov (United States)

    Seals, J. Dennis

    1994-10-01

    The MAMA (Mixed Arithmetic, Multiprocessing Array) module is being developed to evaluate new packaging technologies and processing paradigms for advanced military processing systems. The architecture supports a tight mix of signal, data,and I/O processing at GFLOP throughput rates. It is fabricated using only commercial-on-the-sehlf (COTS) chips and will provide a high level of durability. Its attributes are largely the result of two new interconnection and packaging technologies. Chip-in-board packaging is used to reduce local x-y communication delays and solder joints, while significantly improving board-level packaging density. A unique 3-D interconnection technology called a cross-over cell has been developed to reduce board-to-board communication delays, drive power, glue logic, and card-edge pin-outs. These technologies enable true 3-D structures that are form, fit and connector compatible with conventional line-replacable modules. The module's design rational, packaging technology, and basic architecture will be presented in this paper.

  3. Infrared vertically-illuminated photodiode for chip alignment feedback

    CERN Document Server

    Alloatti, Luca

    2016-01-01

    We report on vertically-illuminated photodiodes fabricated in the GlobalFoundries 45nm 12SOI node and on a packaging concept for optically-interconnected chips. The photodiodes are responsive at 1180 nm, a wavelength currently used in chip-to-chip communications. They have further a wide field-of-view which enables chip-to-board positional feedback in chip-board assemblies. Monolithic integration enables on-chip processing of the positional data.

  4. Crack and flip phacoemulsification technique.

    Science.gov (United States)

    Fine, I H; Maloney, W F; Dillman, D M

    1993-11-01

    The crack and flip phacoemulsification technique combines the advantages of circumferential division of the nucleus and nucleofactis techniques. As such, it adds safety and control to the procedure. We describe each of the surgical maneuvers, including machine settings, and explain the rationale for maneuvers and machine settings.

  5. Packaging fluency

    DEFF Research Database (Denmark)

    Mocanu, Ana; Chrysochou, Polymeros; Bogomolova, Svetlana

    2011-01-01

    Research on packaging stresses the need for packaging design to read easily, presuming fast and accurate processing of product-related information. In this paper we define this property of packaging as “packaging fluency”. Based on the existing marketing and cognitive psychology literature...... on packaging design and processing fluency, our aim is to define and conceptualise packaging fluency. We stress the important role of packaging fluency since it is anticipated that a fluent package would influence the evaluative judgments for a product. We conclude this paper by setting the research agenda...

  6. Packaging fluency

    DEFF Research Database (Denmark)

    Mocanu, Ana; Chrysochou, Polymeros; Bogomolova, Svetlana

    2011-01-01

    Research on packaging stresses the need for packaging design to read easily, presuming fast and accurate processing of product-related information. In this paper we define this property of packaging as “packaging fluency”. Based on the existing marketing and cognitive psychology literature on pac...

  7. An analysis of the pull strength behaviors of fine-pitch, flip chip solder interconnections using a Au-Pt-Pd thick film conductor on Low-Temperature, Co-fired Ceramic (LTCC) substrates.

    Energy Technology Data Exchange (ETDEWEB)

    Uribe, Fernando R.; Kilgo, Alice C.; Grazier, John Mark; Vianco, Paul Thomas; Zender, Gary L.; Hlava, Paul Frank; Rejent, Jerome Andrew

    2008-09-01

    inconsistent proportions of metal and glassy phase particles present during the subsequent firing process. The consequences were subtle, intermittent changes to the thick film microstructure that gave rise to the reaction layer and, thus, the low pull strength phenomenon. A mitigation strategy would be the use of physical vapor deposition (PVD) techniques to create thin film bond pads; this is multi-chip module, deposited (MCM-D) technology.

  8. Mechanically Flexible Active Silicon Chips and Systems Project

    Data.gov (United States)

    National Aeronautics and Space Administration — Using innovative chip thinning technology married with recently available packaging technology, this effort will produce Mechanically Flexible Multifunctional Active...

  9. Flipping the Graduate Qualitative Research Methods Classroom: Did It Lead to Flipped Learning?

    Science.gov (United States)

    Earley, Mark

    2016-01-01

    The flipped, or inverted, classroom has gained popularity in a variety of fields and at a variety of educational levels, from K-12 through higher education. This paper describes the author's positive experience flipping a graduate qualitative research methods classroom. After a review of the current literature on flipped classrooms in higher…

  10. How to Flip the Classroom--"Productive Failure or Traditional Flipped Classroom" Pedagogical Design?

    Science.gov (United States)

    Song, Yanjie; Kapur, Manu

    2017-01-01

    The paper reports a quasi-experimental study comparing the "traditional flipped classroom" pedagogical design with the "productive failure" (Kapur, 2016) pedagogical design in the flipped classroom for a 2-week curricular unit on polynomials in a Hong Kong Secondary school. Different from the flipped classroom where students…

  11. Control Effect of Occupational Hazards in Construction Project of Chip Package%某芯片封装测试项目职业病危害控制效果评价

    Institute of Scientific and Technical Information of China (English)

    康晓熙; 张遵真

    2013-01-01

    目的 评价某芯片封装测试项目职业病危害因素控制效果,为项目竣工验收提供依据.方法 依据相关资料,进行现场职业卫生学调查和职业危害因素检测,采用工程分析、定性定量分析等方法进行评价.结果 噪声、化学毒物、工频电磁场是芯片封装测试生产的主要职业病危害因素.其中,4个噪声测定点超标,该4点均为巡视人员巡检岗位,其接触噪声8h等效声级为77.7dB(A);化学毒物、工频电磁场作业点检测结果均符合国家职业卫生标准.结论 该项目为职业病危害一般的建设项目,该项目采取了卫生工程防护措施与个人防护措施相结合的方法控制职业有害因素,对接触有毒有害作业人员进行职业健康监护,职业病防护措施效果良好.%Objective To evaluate the occupational hazards in construction project of chip package,so as to provide the basis for the inspection by health administrative departments.Methods According to the related data,occupational hygienic investigation was carried out,occupational hazards factors were detected and both qualitative and quantitative analysis methods were applied.Results The main occupational hazard factors in the chip package production were noise,poisonous chemicals and power frequency.Four noise sites for patrol inspection exceed the standard with the Lex8hintensities noise of 77.7dB (A).Poisonous chemicals,power frequency were in accord with the occupational exposure standards.Conclusion The project is a common construction project,the occupational hazard prevention facilities and control measures basically come up to the national occupational health requirements.

  12. 基于TSV技术的CIS芯片晶圆级封装工艺研究%The Research of CIS Chip Wafer Level Packaging Process Based on TSV

    Institute of Scientific and Technical Information of China (English)

    董西英; 徐成翔

    2011-01-01

    TSV-based packaging technology is a kind of high-end technology currently used in MEMS, memory and three-dimensional integrated circuits.This article discusses the TSV-based CIS chip wafer level packaging process which is in the mass production phase and in a leading position in our country.The emphasis of this work focuses on the theoretical and experimental investigations of executing aluminum etching and photoresist removal before metallic coating, and the induced Ni-breeding problem.It is found that the new process flow can shorten the time of photoresist removal, decrease the residua of photoresist and reduce the number of layers of metallic coating.Extending UPW rinse time in electroplating process each time, avoiding forming Nickel particles in plating solution in EN Ni.Lowering zinc concentration when zinc plating and increase nitric acid cleaning steps therefore circumvent the problem of Ni-breeding.The results are helpful to improve the efficiency, increase the passing rate of the chips greatly and reduce the costs.%基于TSV技术的封装技术是目前MEMS产品、存储器、3D IC封装中的高端和热点技术.本文论述了在国内处于领先并正在量产化研究阶段的基于TSV技术的CIS芯片晶圆级封装工艺流程.通过理论分析和实验,重点研究了在封装流程中将铝刻蚀、去胶提前到金属镀覆之前的意义和所出现的镍滋生问题.研究表明,将铝刻蚀、去胶提前到金属镀覆之前可以缩短去胶时间,减少光刻胶的残留和金属镀覆层数;通过延长金属镀覆过程中每次UPW冲洗时间,在EN Ni中防止镀液结镍,并在镀锌时降低锌液的粘附性和镀锌后增加硝酸清洗步骤,即可消除镍滋生.以上研究对于提高封装效率和合格芯片率,降低成本是很有意义的.

  13. How material, visual and verbal cues on packaging influence consumer expectations and willingness to buy: The case of crisps (potato chips) in Spain.

    Science.gov (United States)

    Rebollar, Rubén; Gil, Ignacio; Lidón, Iván; Martín, Javier; Fernández, María J; Rivera, Sandra

    2017-09-01

    This paper analyses the influence that certain aspects of packaging design have on the consumer expectations of a series of sensory and non-sensory attributes and on willingness to buy for a bag of crisps in Spain. A two-part experiment was conducted in which 174 people evaluated the attributes for different stimuli using an online survey. In the first part, four stimuli were created in which two factors were varied: the packaging material and the image displayed. Interaction was identified between both factors for the attributes Crunchy, High quality and Artisan. For the attributes Salty, Crunchy and Willingness to buy, the image was the only significant factor, with the image displaying crisps ready for consumption being the only one that obtained higher scores. For the attribute Intense flavour, no statistically significant differences were identified among the stimuli. In general terms, the image displayed on the bag had a greater influence than the material from which the bag was made. In the second part, an analysis was made of the most effective way (visual cues versus verbal cues) to transmit the information that the crisps were fried in olive oil. To this end, two stimuli were designed: one displaying an image of an oil cruet and another with an allusive text. For all the attributes (Intense flavour, Crunchy, Artisan, High quality, Healthy and Willingness to buy), higher scores were obtained with the image than with the text. These results have important implications for crisps producers, marketers and packaging designers. Copyright © 2017 Elsevier Ltd. All rights reserved.

  14. To Flip or Not to Flip? Analysis of a Flipped Classroom Pedagogy in a General Biology Course

    Science.gov (United States)

    Heyborne, William H.; Perrett, Jamis J.

    2016-01-01

    In an attempt to better understand the flipped technique and evaluate its purported superiority in terms of student learning gains, the authors conducted an experiment comparing a flipped classroom to a traditional lecture classroom. Although the outcomes were mixed, regarding the superiority of either pedagogical approach, there does seem to be a…

  15. Final Design and Integration of Micro-Chip Inductive Edge Sensors for the Seven Segment Demonstrator. Testing of Integrated Edge Sensors in Test Packages

    Science.gov (United States)

    Karpinsky, John

    1997-01-01

    The contractor attended the critical design review and evaluated the presentations of other team members and presented data on the inductive edge sensor. The prototype micro-chip inductive edge sensor was evaluated, and devices were found to have a number of characteristics which made them unsuitable for installation on the seven segment demonstrator. The amplifier bandwidth was too low, the output drive current was too small, and there is an interaction between the digital circuitry and the amplifier that causes the amplifier to stop functioning. Therefore, the inductive edge sensors were not installed on the seven segment demonstrator. The contractor has participated in instruction, problem analysis, and provided technical assistance to NASA and its contractors for the development of 8 hexagonal mirror faceplates with electronics and edge sensors.

  16. Designing of Low Power CNTFET Based D Flip-Flop Using Forced Stack Technique

    Directory of Open Access Journals (Sweden)

    Vikas Sharma

    2015-04-01

    Full Text Available Low Power devices in small packages is the need of present and future electronic devices. Electronics Industry is making devices which can be planted in human bodies. CMOS Technology won‟t be able to deliver such devices because it shows short channel effects in Nano scale. So, to overcome the problems of CMOS technology we use CNTs (Carbon Nano Tubes. In electronic devices, power is consumed by various elements like flip-flop, latches, clock sources. So in order to reduce power of a system we used to reduce power consumed by flip-flops. In this paper we design an existing flip-flop “Low power clocked pass transistor flip-flop (LCPTFF” on CNTFET using Stanford CNTFET model for reference. We propose a design of CNTFET based Forced Stack Low Power Clocked Pass Transistor Flip-Flop (CN-FS-LCPTFF and observe 12% to 25% power reduction in various conditions like temperature change, CNTFET diameter change, and different voltage supply.

  17. High performance microsystem packaging: A perspective

    Energy Technology Data Exchange (ETDEWEB)

    Romig, A.D. Jr.; Dressendorfer, P.V.; Palmer, D.W.

    1997-10-01

    The second silicon revolution will be based on intelligent, integrated microsystems where multiple technologies (such as analog, digital, memory, sensor, micro-electro-mechanical, and communication devices) are integrated onto a single chip or within a multichip module. A necessary element for such systems is cost-effective, high-performance packaging. This paper examines many of the issues associated with the packaging of integrated microsystems, with an emphasis on the areas of packaging design, manufacturability, and reliability.

  18. Design of a high-speed vertical transition in LTCC for interposers suitable for packaging photonic integrated circuits

    Science.gov (United States)

    Jezzini, M. A.; Marraccini, P. J.; Peters, F. H.

    2016-05-01

    The packaging of high speed Photonic Integrated Circuits (PICs) should maintain the electrical signal integrity. The standard packaging of high speed PICs relies on wire bonds. This is not desirable because wire bonds degrade the quality of the electrical signal. The research presented in this paper proposes to replace wire bonds with an interposer with multilevel transmission lines. By attaching the PIC by flip chip onto the interposer, the use of wire bonds is avoided. The main concern for designing an interposer with multilevel transmission lines is the vertical transition, which must be designed to avoid return and radiation losses. In this paper, a novel design of a high speed vertical transition for Low Temperature Co-fired Ceramic (LTCC) is presented. The proposed vertical transition is simpler than others recently published in the literature, due to eliminating the need for additional ceramic layers or air cavities. A LTCC board was fabricated with several variations of the presented transition to find the optimal dimensions of the structure. The structures were fabricated then characterized and have a 3 dB bandwidth of 37 GHz and an open eye diagram at 44 Gbps. A full wave electromagnetic simulation is described and compared with good agreement to the measurements. The results suggest that an LTCC board with this design can be used for 40 Gbps per channel applications. Keywords: Photonics packaging, Low Temperature Co-Fired Ceramics.

  19. The Flipped Classroom: A Twist on Teaching

    Science.gov (United States)

    Schmidt, Stacy M. P.; Ralph, David L.

    2016-01-01

    The traditional classroom has utilized the "I Do", "We Do", "You Do" as a strategy for teaching for years. The flipped classroom truly flips that strategy. The teacher uses "You Do", "We Do", "I Do" instead. Homework, inquiry, and investigation happen in the classroom. At home students…

  20. Flipping Quantitative Classes: A Triple Win

    Science.gov (United States)

    Swart, William; Wuensch, Karl L.

    2016-01-01

    In the "flipped" class, students use online materials to learn what is traditionally learned by attending lectures, and class time is used for interactive group learning. A required quantitative business class was taught as a flipped classroom in an attempt to improve student satisfaction in the course and reduce the "transactional…

  1. Best Practices for Launching a Flipped Classroom

    Science.gov (United States)

    Hall, Ashley A.; DuFrene, Debbie D.

    2016-01-01

    Popularity is growing for flipped classroom instruction, which replaces lectures with out-of-class delivery of streaming video, reading materials, online chats, and other modalities. Face-to-face class time is spent on instructor-student and student-student interaction, including small group problem solving and discussion. Classroom flipping has…

  2. Technology: Differentiating Instruction by Flipping the Classroom

    Science.gov (United States)

    Siegle, Del

    2014-01-01

    Flipping the classroom can be an effective instructional strategy for differentiating instruction for gifted and talented students. The author presents a rationale for using the strategy with gifted students, possible problems educators might encounter, and practical tips for beginning the process of flipping the classroom.

  3. Just in Time to Flip Your Classroom

    Science.gov (United States)

    Lasry, Nathaniel; Dugdale, Michael; Charles, Elizabeth

    2014-01-01

    With advocates like Sal Khan and Bill Gates, flipped classrooms are attracting an increasing amount of media and research attention. We had heard Khan's TED talk and were aware of the concept of inverted pedagogies in general. Yet it really hit home when we accidentally flipped our classroom. Our objective was to better prepare our students…

  4. The Flipped Classroom. IDEA Paper #57

    Science.gov (United States)

    Braseby, Anne M.

    2014-01-01

    Use of the word "flipped" has become the latest buzzword in the educational world. This paper explores the different uses of the term "flipped," examines the research to date, and discusses how and why teachers are starting to use the new model. It offers suggestions for activities both inside and outside of the classroom to…

  5. Conceptualizing "Homework" in Flipped Mathematics Classes

    Science.gov (United States)

    de Araujo, Zandra; Otten, Samuel; Birisci, Salih

    2017-01-01

    Flipped instruction is becoming more common in the United States, particularly in mathematics classes. One of the defining characteristics of this increasingly popular instructional format is the homework teachers assign. In contrast to traditional mathematics classes in which homework consists of problem sets, homework in flipped classes often…

  6. Just in Time to Flip Your Classroom

    Science.gov (United States)

    Lasry, Nathaniel; Dugdale, Michael; Charles, Elizabeth

    2014-01-01

    With advocates like Sal Khan and Bill Gates, flipped classrooms are attracting an increasing amount of media and research attention. We had heard Khan's TED talk and were aware of the concept of inverted pedagogies in general. Yet it really hit home when we accidentally flipped our classroom. Our objective was to better prepare our students…

  7. Diverse Perspectives on a Flipped Biostatistics Classroom

    Science.gov (United States)

    Schwartz, Todd A.; Andridge, Rebecca R.; Sainani, Kirstin L.; Stangle, Dalene K.; Neely, Megan L.

    2016-01-01

    "Flipping" the classroom refers to a pedagogical approach in which students are first exposed to didactic content outside the classroom and then actively use class time to apply their newly attained knowledge. The idea of the flipped classroom is not new, but has grown in popularity in recent years as the necessary technology has…

  8. MEMS packaging

    CERN Document Server

    Hsu , Tai-Ran

    2004-01-01

    MEMS Packaging discusses the prevalent practices and enabling techniques in assembly, packaging and testing of microelectromechanical systems (MEMS). The entire spectrum of assembly, packaging and testing of MEMS and microsystems, from essential enabling technologies to applications in key industries of life sciences, telecommunications and aerospace engineering is covered. Other topics included are bonding and sealing of microcomponents, process flow of MEMS and microsystems packaging, automated microassembly, and testing and design for testing.The Institution of Engineering and Technology is

  9. Just in Time to Flip Your Classroom

    Science.gov (United States)

    Lasry, Nathaniel; Dugdale, Michael; Charles, Elizabeth

    2014-01-01

    With advocates like Sal Khan and Bill Gates, flipped classrooms are attracting an increasing amount of media and research attention.2 We had heard Khan's TED talk and were aware of the concept of inverted pedagogies in general. Yet it really hit home when we accidentally flipped our classroom. Our objective was to better prepare our students for class. We set out to effectively move some of our course content outside of class and decided to tweak the Just-in-Time Teaching approach (JiTT).3 To our surprise, this tweak—which we like to call the flip-JiTT—ended up completely flipping our classroom. What follows is narrative of our experience and a procedure that any teacher can use to extend JiTT to a flipped classroom.

  10. Just in Time to Flip Your Classroom

    CERN Document Server

    Lasry, Nathaniel; Charles, Elizabeth

    2013-01-01

    With advocates like Sal Khan and Bill Gates, flipped classrooms are attracting an increasing amount of media and research attention. We had heard Khan's TED talk and were aware of the concept of inverted pedagogies in general. Yet, it really hit home when we accidentally flipped our classroom. Our objective was to better prepare our students for class. We set out to effectively move some of our course content outside of class and decided to tweak the Just-in-Time-Teaching approach (JiTT). To our surprise, this tweak - which we like to call the flip-JiTT - ended up completely flipping our classroom. What follows is narrative of our experience and a procedure that any teacher can use to extend JiTT to a flipped classroom.

  11. Development of a One-package Epoxy Resin Sealant for Electronic Memory Chips%存储芯片用单组分环氧胶粘剂的研制

    Institute of Scientific and Technical Information of China (English)

    戚渭新

    2002-01-01

    A method of making a one-package epoxy resin sealant for electronic memory chips and the characteristics of the sealant were presented.. The process and the conditions of preparing the latent curing agent were discussed in detail. The principle of preparing the curing agent is to lower reactivity of a heterocyclic amine and envelop it simultaneously.This sealant can cure rapidly and completely in the condition of 110 ℃ and 30 min, and it is stable for storage at 20 ℃. Its application showed that the sealant can take the place of the imported sealant.%介绍了电子存储芯片用密封用单组分环氧胶粘剂的制备方法及产品特点,详细讨论了潜伏性固化剂的制备条件,本固化剂采用杂环胺减活性同时进行包裹的方法制备,110 ℃×30min可固化,20 ℃可贮存6个月,使用结果证明可以取代进口胶.

  12. Flipped classroom: a review of recent literature

    Directory of Open Access Journals (Sweden)

    Huseyin Uzunboylu

    2015-07-01

    Full Text Available The use of learning technologies, especially multimedia provide varied facilities for students’ learning that are not possible with other media. Pedagogical literature has proved that individuals have different learning styles. Flipped classroom is a pedagogical approach which means that activities that have traditionally taken place inside the classroom take place outside the classroom and vice versa. Flipped classroom environment ensures that students become more active participants compared with the traditional classroom. The purpose of this paper is to fulfil the needs regarding the review of recent literature on the use of flipped classroom approach in education. The contribution of flipped classroom to education is discussed in relation to the change of students' and instructors' role. Subsequently, flipped classroom applications in various disciplines of education are illustrated. The recommendations made in the literature for design specifications that integrate flipped classrooms with technology are discussed. The paper concludes that a careful consideration of the warnings and recommendations made in the literature can help to produce effective flipped classroom environments and also this paper attempts to inform those who are thinking of using new technologies and approaches to deliver courses.

  13. FLIPS: Friendly Lisp Image Processing System

    Science.gov (United States)

    Gee, Shirley J.

    1991-08-01

    The Friendly Lisp Image Processing System (FLIPS) is the interface to Advanced Target Detection (ATD), a multi-resolutional image analysis system developed by Hughes in conjunction with the Hughes Research Laboratories. Both menu- and graphics-driven, FLIPS enhances system usability by supporting the interactive nature of research and development. Although much progress has been made, fully automated image understanding technology that is both robust and reliable is not a reality. In situations where highly accurate results are required, skilled human analysts must still verify the findings of these systems. Furthermore, the systems often require processing times several orders of magnitude greater than that needed by veteran personnel to analyze the same image. The purpose of FLIPS is to facilitate the ability of an image analyst to take statistical measurements on digital imagery in a timely fashion, a capability critical in research environments where a large percentage of time is expended in algorithm development. In many cases, this entails minor modifications or code tinkering. Without a well-developed man-machine interface, throughput is unduly constricted. FLIPS provides mechanisms which support rapid prototyping for ATD. This paper examines the ATD/FLIPS system. The philosophy of ATD in addressing image understanding problems is described, and the capabilities of FLIPS are discussed, along with a description of the interaction between ATD and FLIPS. Finally, an overview of current plans for the system is outlined.

  14. Packaging Effects on RadFET Sensors for High Energy Physics Experiments

    CERN Document Server

    Mekki, J; Glaser, M; Guatelli, S; Moll, M; Pia, M G; Ravotti, F

    2009-01-01

    RadFETs in customized chip carrier packages are installed in the LHC Experiments as radiation monitors. The package influence on the dose measurement in the complex LHC radiation environment is evaluated using Geant4 simulations and experimental data.

  15. Comparing the Effectiveness of Blended, Semi-Flipped, and Flipped Formats in an Engineering Numerical Methods Course

    Science.gov (United States)

    Clark, Renee M.; Kaw, Autar; Besterfield-Sacre, Mary

    2016-01-01

    Blended, flipped, and semi-flipped instructional approaches were used in various sections of a numerical methods course for undergraduate mechanical engineers. During the spring of 2014, a blended approach was used; in the summer of 2014, a combination of blended and flipped instruction was used to deliver a semi-flipped course; and in the fall of…

  16. A counting pixel chip and sensor system for X-ray imaging

    Energy Technology Data Exchange (ETDEWEB)

    Fischer, P.; Hausmann, J.; Helmich, A.; Lindner, M.; Wermes, N. [Universitaet Bonn (Germany). Physikalisches Institut; Blanquart, L. [CNRS, Marseille (France). Centre de Physique des Particules

    1999-08-01

    Results obtained with a (photon) counting pixel imaging chip connected to a silicon pixel sensor using the bump and flip-chip technology are presented. The performance of the chip electronics is characterized by an average equivalent noise charge (ENC) below 135 e and a threshold spread of less than 35 e after individual threshold adjust, both measured with a sensor attached. First results on the imaging performance are also reported.

  17. Twelve tips for "flipping" the classroom.

    Science.gov (United States)

    Moffett, Jennifer

    2015-04-01

    The flipped classroom is a pedagogical model in which the typical lecture and homework elements of a course are reversed. The following tips outline the steps involved in making a successful transition to a flipped classroom approach. The tips are based on the available literature alongside the author's experience of using the approach in a medical education setting. Flipping a classroom has a number of potential benefits, for example increased educator-student interaction, but must be planned and implemented carefully to support effective learning.

  18. Suggestions for Implementing Flipped Classroom in China

    Institute of Scientific and Technical Information of China (English)

    周婷

    2016-01-01

    Educators in the twenty-first century are constantly adopting new technologies and pedagogies. Flipped Classroom Model is one of the most promising approaches to transforming learning experiences, which has been applied to both K-12 edu-cation and higher education at home and abroad. Influenced by culture and learning styles, the effectiveness and concrete imple-mentation strategies of this teaching model is different in different countries. How to localize the model in China is an important question for educators to think about. The paper makes suggestions for implementing Flipped Classroom in China, aiming at helping teachers to flip their classrooms successfully.

  19. Enhancing student engagement using the flipped classroom.

    Science.gov (United States)

    Gilboy, Mary Beth; Heinerichs, Scott; Pazzaglia, Gina

    2015-01-01

    The flipped classroom is an innovative pedagogical approach that focuses on learner-centered instruction. The purposes of this report were to illustrate how to implement the flipped classroom and to describe students' perceptions of this approach within 2 undergraduate nutrition courses. The template provided enables faculty to design before, during, and after class activities and assessments based on objectives using all levels of Bloom's taxonomy. The majority of the 142 students completing the evaluation preferred the flipped method compared with traditional pedagogical strategies. The process described in the report was successful for both faculty and students.

  20. RF and microwave microelectronics packaging II

    CERN Document Server

    Sturdivant, Rick

    2017-01-01

    Reviews RF, microwave, and microelectronics assembly process, quality control, and failure analysis Bridges the gap between low cost commercial and hi-res RF/Microwave packaging technologies Engages in an in-depth discussion of challenges in packaging and assembly of advanced high-power amplifiers This book presents the latest developments in packaging for high-frequency electronics. It is a companion volume to “RF and Microwave Microelectronics Packaging” (2010) and covers the latest developments in thermal management, electrical/RF/thermal-mechanical designs and simulations, packaging and processing methods, and other RF and microwave packaging topics. Chapters provide detailed coverage of phased arrays, T/R modules, 3D transitions, high thermal conductivity materials, carbon nanotubes and graphene advanced materials, and chip size packaging for RF MEMS. It appeals to practicing engineers in the electronic packaging and high-frequency electronics domain, and to academic researchers interested in underst...

  1. FLIP the Switch: Regulation of Apoptosis and Necroptosis by cFLIP

    Directory of Open Access Journals (Sweden)

    Yuichi Tsuchiya

    2015-12-01

    Full Text Available cFLIP (cellular FLICE-like inhibitory protein is structurally related to caspase-8 but lacks proteolytic activity due to multiple amino acid substitutions of catalytically important residues. cFLIP protein is evolutionarily conserved and expressed as three functionally different isoforms in humans (cFLIPL, cFLIPS, and cFLIPR. cFLIP controls not only the classical death receptor-mediated extrinsic apoptosis pathway, but also the non-conventional pattern recognition receptor-dependent apoptotic pathway. In addition, cFLIP regulates the formation of the death receptor-independent apoptotic platform named the ripoptosome. Moreover, recent studies have revealed that cFLIP is also involved in a non-apoptotic cell death pathway known as programmed necrosis or necroptosis. These functions of cFLIP are strictly controlled in an isoform-, concentration- and tissue-specific manner, and the ubiquitin-proteasome system plays an important role in regulating the stability of cFLIP. In this review, we summarize the current scientific findings from biochemical analyses, cell biological studies, mathematical modeling, and gene-manipulated mice models to illustrate the critical role of cFLIP as a switch to determine the destiny of cells among survival, apoptosis, and necroptosis.

  2. Base flipping in tn10 transposition: an active flip and capture mechanism.

    Directory of Open Access Journals (Sweden)

    Julien Bischerour

    Full Text Available The bacterial Tn5 and Tn10 transposases have a single active site that cuts both strands of DNA at their respective transposon ends. This is achieved using a hairpin intermediate that requires the DNA to change conformation during the reaction. In Tn5 these changes are controlled in part by a flipped nucleoside that is stacked on a tryptophan residue in a hydrophobic pocket of the transposase. Here we have investigated the base flipping mechanism in Tn10 transposition. As in Tn5 transposition, we find that base flipping takes place after the first nick and is required for efficient hairpin formation and resolution. Experiments with an abasic substrate show that the role of base flipping in hairpin formation is to remove the base from the DNA helix. Specific interactions between the flipped base and the stacking tryptophan residue are required for hairpin resolution later in the reaction. We show that base flipping in Tn10 transposition is not a passive reaction in which a spontaneously flipped base is captured and retained by the protein. Rather, it is driven in part by a methionine probe residue that helps to force the flipped base from the base stack. Overall, it appears that base flipping in Tn10 transposition is similar to that in Tn5 transposition.

  3. Development of vacuum underfill technology for a 3D chip stack

    Science.gov (United States)

    Sakuma, Katsuyuki; Kohara, Sayuri; Sueoka, Kuniaki; Orii, Yasumitsu; Kawakami, Mikio; Asai, Kazuo; Hirayama, Yoshikazu; Knickerbocker, John U.

    2011-03-01

    We developed a vacuum underfill technology for 3D chip stacks and for flip chips in high performance system integration. We fabricated a 3D prototype chip stack using the vacuum underfill technology to apply the adhesive. The underfill was injected into each 6 µm gaps in a 3-layer chip stack and no voids were detected in acoustic microscopy images. Electrical tests and thermal reliability tests were used to measure the resistance of the vertical interconnections and the impact of the underfill. The results showed there was minimal difference in the average interconnection resistance of the chip stack with and without underfill.

  4. How we flipped the medical classroom.

    Science.gov (United States)

    Sharma, Neel; Lau, C S; Doherty, Iain; Harbutt, Darren

    2015-04-01

    Flipping the classroom centres on the delivery of print, audio or video based material prior to a lecture or class session. The class session is then dedicated to more active learning processes with application of knowledge through problem solving or case based scenarios. The rationale behind this approach is that teachers can spend their face-to-face time supporting students in deeper learning processes. In this paper we provide a background literature review on the flipped classroom along with a three step approach to flipping the classroom comprising implementing, enacting and evaluating this form of pedagogy. Our three step approach is based on actual experience of delivering a flipped classroom at the University of Hong Kong. This initiative was evaluated with positive results. We hope our experience will be transferable to other medical institutions.

  5. En didaktisk model for Flipped Classroom

    DEFF Research Database (Denmark)

    Levinsen, Henrik; Foss, Kristian Kildemoes; Andersen, Thomas Dyreborg

    2016-01-01

    I artiklen præsenterer vi en model over flipped classroom som didaktisk metode udviklet med henblik på at stilladsere både de lærere, som gerne vil prøve kræfter med en flipped classroom-baseret praksis, og dem som allerede har erfaring, men kan have glæde af at bruge modellen til at kvalificere...... deres flipped classroom-undervisning. Modellen kan bidrage til erkendelsen af, at flipped classroom er noget nær et paradigmeskifte i forståelsen af god undervisning. Her tænkes på det skift i fokus metoden indebærer fra, at læreren er mest aktiv, til at eleverne er de mest aktive. Særligt for den...

  6. Flip to Regular Triangulation and Convex Hull.

    Science.gov (United States)

    Gao, Mingcen; Cao, Thanh-Tung; Tan, Tiow-Seng

    2017-02-01

    Flip is a simple and local operation to transform one triangulation to another. It makes changes only to some neighboring simplices, without considering any attribute or configuration global in nature to the triangulation. Thanks to this characteristic, several flips can be independently applied to different small, non-overlapping regions of one triangulation. Such operation is favored when designing algorithms for data-parallel, massively multithreaded hardware, such as the GPU. However, most existing flip algorithms are designed to be executed sequentially, and usually need some restrictions on the execution order of flips, making them hard to be adapted to parallel computation. In this paper, we present an in depth study of flip algorithms in low dimensions, with the emphasis on the flexibility of their execution order. In particular, we propose a series of provably correct flip algorithms for regular triangulation and convex hull in 2D and 3D, with implementations for both CPUs and GPUs. Our experiment shows that our GPU implementation for constructing these structures from a given point set achieves up to two orders of magnitude of speedup over other popular single-threaded CPU implementation of existing algorithms.

  7. Effect of electromigration on interfacial reaction in Ni/Sn3.0Ag0.5Cu/Au/Pd/Ni-P flip chip solder joints%电迁移对Ni/Sn3.0Ag0.5Cu/Au/Pd/Ni—P倒装焊点界面反应的影响

    Institute of Scientific and Technical Information of China (English)

    黄明亮; 陈雷达; 周少明; 赵宁

    2012-01-01

    本文研究了150℃,1.0×104A/cm2条件下电迁移对Ni/Sn3.0Ag0.5Cu/Au/Pd/Ni-P倒装焊点界面反应的影响.回流后在solder/Ni和solder/NiP的界面上均形成(Cu,Ni)6Sn5类型金属间化合物.时效过程中两端界面化合物都随时间延长而增厚,且化合物类型都由(Cu,Ni)6Sn5转变为(Ni,Cu)3Sn4.电迁移过程中电子的流动方向对Ni—P层的消耗起着决定性作用.当电子从基板端流向芯片端时,电迁移促进了Ni—P层的消耗,600h后阴极端Ni-P层全部转变为Ni2SnP层.阴极界面处由于Ni2SnP层的存在,使界面Cu-Sn—Ni三元金属间化合物发生电迁移脱落溶解,而且由于Ni2SnP层与Cu焊盘的结合力较差,在Ni2SnP/Cu界面处会形成裂纹.当电子从芯片端流向基板端时,阳极端Ni—P层并没有发生明显的消耗.电流拥挤效应导致了阴极芯片端Ni层和Cu焊盘均发生了局部快速溶解,溶解到钎料中的Cu和Ni原子沿电子运动的方向往阳极运动并在钎料中形成了大量的化合物颗粒.电迁移过程中(Au,Pd,Ni)Sn4的聚集具有方向性,即(Au,Pd,Ni)Sn4因电流作用而在阳极界面处聚集.%The effect of electromigration (EM) on the interracial reaction in the Ni/Sn3.0Ag0.5Cu/Au/Pd/Ni-P flip chip solder joint is investigated under a current density of 1.0 ×104 A/cm2 at 150℃. The (Cu,Ni)6Sn5 intermetallic compounds (IMCs) form at both solder/Ni and solder/Ni-P interfaces in the as-reflowed state. During aging at 150℃, the (Cu,Ni)6Sn5 interfacial IMCs grow thicker and transform into (Ni,Cu)3Sn4 type after 200 h at solder/Ni interface and 600 h at solder/Ni-P interface, respectively. During EM, the current direction plays an important role in Ni-P layer consumption. When electrons flow from Ni-P to Ni, EM enhances the consumption of Ni-P, i.e., the Ni-P s completely consumed and transforms into Ni2SnP after EM for 600 h. There is

  8. ConfChem Conference on Flipped Classroom: Flipping at an Open-Enrollment College

    Science.gov (United States)

    Butzler, Kelly B.

    2015-01-01

    The flipped classroom is a blended, constructivist learning environment that reverses where students gain and apply knowledge. Instructors from K-12 to the college level are interested in the prospect of flipping their classes, but are unsure how and with which students to implement this learning environment. There has been little discussion…

  9. Research on Flipping College Algebra: Lessons Learned and Practical Advice for Flipping Multiple Sections

    Science.gov (United States)

    Overmyer, Jerry

    2015-01-01

    This quantitative research compares five sections of College Algebra using flipped classroom methods with six sections using the traditional lecture/homework structure and its effect on student achievement as measured through a common final exam. Common final exam scores were the dependent variables. Instructors of flipped sections who had…

  10. Research on Flipping College Algebra: Lessons Learned and Practical Advice for Flipping Multiple Sections

    Science.gov (United States)

    Overmyer, Jerry

    2015-01-01

    This quantitative research compares five sections of College Algebra using flipped classroom methods with six sections using the traditional lecture/homework structure and its effect on student achievement as measured through a common final exam. Common final exam scores were the dependent variables. Instructors of flipped sections who had…

  11. Packaging considerations for planar optical interconnection systems.

    Science.gov (United States)

    Acklin, B; Jahns, J

    1994-03-10

    We discuss various aspects of building an integrated optoelectronic system that is based on the concept of planar optics. A particular optical interconnection system has been fabricated and demonstrated. It provides parallel interconnections with 1024 optical channels that could be useful as an optical backplane in an optoelectronic multichip module. We consider the design and the fabrication of the optical system, schemes for the hybrid integration with optoelectronic device arrays, and the thermal management of an integrated system. The proposed hybrid integration scheme is based on mature technologies such as thermal anodic bonding and flip-chip bonding. Possibilities for efficient heat sinking are described.

  12. Additive manufacturing approaches for stress relief in semiconductor die packaging

    NARCIS (Netherlands)

    Zon, C.M.B. van der; Wiel, A. van der; Maalderink, H.H.; Vaes, M.H.E.; Aulbers, A.P.; Vorst, L.T.G. van de; Cate, A.T. ten; Furrer, J.F.; Burssens, J.W.; Chen, J.

    2012-01-01

    Packaging of semiconductor chips, especially MEMS-based, always causes stress on the functional areas of the die causing unpredictable changes in chip performance. As a consequence such devices can only be calibrated individually after complete assembly. Melexis and TNO have developed an approach to

  13. Additive manufacturing approaches for stress relief in semiconductor die packaging

    NARCIS (Netherlands)

    Zon, C.M.B. van der; Wiel, A. van der; Maalderink, H.H.; Vaes, M.H.E.; Aulbers, A.P.; Vorst, L.T.G. van de; Cate, A.T. ten; Furrer, J.F.; Burssens, J.W.; Chen, J.

    2012-01-01

    Packaging of semiconductor chips, especially MEMS-based, always causes stress on the functional areas of the die causing unpredictable changes in chip performance. As a consequence such devices can only be calibrated individually after complete assembly. Melexis and TNO have developed an approach to

  14. Comparison of different LED Packages

    Science.gov (United States)

    Dieker, Henning; Miesner, Christian; Püttjer, Dirk; Bachl, Bernhard

    2007-09-01

    In this paper different technologies for LED packaging are compared, focusing on Chip on Board (COB) and SMD technology. The package technology which is used depends on the LED application. A critical fact in LED technology is the thermal management, especially for high brightness LED applications because the thermal management is important for reliability, lifetime and electrooptical performance of the LED module. To design certain and long life LED applications knowledge of the heat flow from LEDs to the complete application is required. High sophisticated FEM simulations are indispensable for modern development of high power LED applications. We compare simulations of various substrate materials and packaging technologies simulated using FLOTHERM software. Thereby different substrates such as standard FR4, ceramic and metal core printed circuit boards are considered. For the verification of the simulated results and the testing of manufactured modules, advanced measurement tools are required. We show different ways to experimentally characterize the thermal behavior of LED modules. The thermal path is determined by the transient thermal analysis using the MicReD T3Ster analyzer. Afterwards it will be compared to the conventional method using thermocouples. The heat distribution over the module is investigated by an IR-Camera. We demonstrate and compare simulation and measurement results of Chip-on-Board (COB) and Sub-Mounted Devices (SMD) technology. The results reveal that for different applications certain packages are ideal.

  15. Present Information with the Chalkboard and Flip Chart. Second Edition. Module C-29 of Category C--Instructional Execution. Professional Teacher Education Module Series.

    Science.gov (United States)

    American Association for Vocational Instructional Materials, Athens, GA.

    This module for vocational teachers, one in a series of performance-based teacher education learning packages, focuses on skills dealing with methods and strategies for delivering instruction. The purpose for the module is to help educators become competent in using chalkboards and flip charts to present lessons and in determining how to choose…

  16. Use of Flipped Classroom Technology in Language Learning

    OpenAIRE

    Evseeva, Arina; Solozhenko, Anton

    2015-01-01

    The flipped classroom as a key component of blended learning arouses great interest among researchers and educators nowadays. The technology of flipped classroom implies such organization of the educational process in which classroom activities and homework assignments are reversed. The present paper gives the overview of the flipped classroom technology and explores its potential for both teachers and students. The authors present the results obtained from the experience of the flipped class...

  17. Bridging the gap with flipped classroom

    DEFF Research Database (Denmark)

    Selberg, Hanne; Topperzer, Martha

    2016-01-01

    Bridging the gap with flipped classroom Hanne Selberg, Metropolitan University College, Copenhagen, Martha Topperzer, University Hospital Rigshospitalet, Copenhagen, Denmark Background and aims Consistent with the strategy of increasing digitization and learner-centred teaching models...... in the nursing curriculum, we have reversed selected traditional lectures into simulation based teaching activities embedded in a ten week Pediatric Nursing module for third year nursing students. The current pilot study seeks to explore the impact on students’ learning and commitment when flipping the classroom...... using educational technologies such as online preparation contents and simulation based scenarios. Furthermore, the objective is to enhance theory-practice integration in the educational setting. Materials & Methods The flipped classroom model replaces three theoretical lectures addressing disease...

  18. Flipping the statistics classroom in nursing education.

    Science.gov (United States)

    Schwartz, Todd A

    2014-04-01

    Flipped classrooms are so named because they substitute the traditional lecture that commonly encompasses the entire class period with active learning techniques, such as small-group work. The lectures are delivered instead by using an alternative mode--video recordings--that are made available for viewing online outside the class period. Due to this inverted approach, students are engaged with the course material during the class period, rather than participating only passively. This flipped approach is gaining popularity in many areas of education due to its enhancement of student learning and represents an opportunity for utilization by instructors of statistics courses in nursing education. This article presents the author's recent experiences with flipping a statistics course for nursing students in a PhD program, including practical considerations and student outcomes and reaction. This transformative experience deepened the level of student learning in a way that may not have occurred using a traditional format.

  19. Experimental plug and play quantum coin flipping

    Science.gov (United States)

    Pappa, Anna; Jouguet, Paul; Lawson, Thomas; Chailloux, André; Legré, Matthieu; Trinkler, Patrick; Kerenidis, Iordanis; Diamanti, Eleni

    2014-04-01

    Performing complex cryptographic tasks will be an essential element in future quantum communication networks. These tasks are based on a handful of fundamental primitives, such as coin flipping, where two distrustful parties wish to agree on a randomly generated bit. Although it is known that quantum versions of these primitives can offer information-theoretic security advantages with respect to classical protocols, a demonstration of such an advantage in a practical communication scenario has remained elusive. Here we experimentally implement a quantum coin flipping protocol that performs strictly better than classically possible over a distance suitable for communication over metropolitan area optical networks. The implementation is based on a practical plug and play system, developed by significantly enhancing a commercial quantum key distribution device. Moreover, we provide combined quantum coin flipping protocols that are almost perfectly secure against bounded adversaries. Our results offer a useful toolbox for future secure quantum communications.

  20. Stochastic Flips on Two-letter Words

    CERN Document Server

    Bodini, Olivier; Regnault, Damien

    2010-01-01

    This paper introduces a simple Markov process inspired by the problem of quasicrystal growth. It acts over two-letter words by randomly performing \\emph{flips}, a local transformation which exchanges two consecutive different letters. More precisely, only the flips which do not increase the number of pairs of consecutive identical letters are allowed. Fixed-points of such a process thus perfectly alternate different letters. We show that the expected number of flips to converge towards a fixed-point is bounded by $O(n^3)$ in the worst-case and by $O(n^{5/2}\\ln{n})$ in the average-case, where $n$ denotes the length of the initial word.

  1. Coding Education in a Flipped Classroom

    Directory of Open Access Journals (Sweden)

    Vasfi Tugun

    2017-08-01

    Full Text Available The main purpose of this research is to determine the influence of the flipped classroom model on digital game development and student views on the model. 9th grade students attending Bilişim Teknolojiler II at secondary level participated in the study. The research is an experimental research, designed according to the pretest-posttest research model with experimental and control groups. In the experimental group, the lectures were carried out according to the flipped classroom model while the control group was taught with the traditional methods in the laboratory environment. As a result of the research, the success of the digital game development and the opinions of the students were favored by the experimental group students who were educated with the flipped classroom model. The results obtained in the last part of the study and suggestions for the results are discussed.

  2. The flipped classroom: strategies for an undergraduate nursing course.

    Science.gov (United States)

    Schlairet, Maura C; Green, Rebecca; Benton, Melissa J

    2014-01-01

    This article presents the authors' experience with flipping a fundamental concepts of nursing course for students in an undergraduate baccalaureate program. Authors describe implementing a flipped class, practical strategies to transform students' learning experience, and lessons learned. This article serves as a guide to faculty and programs seeking to develop and implement the flipped class model in nursing education.

  3. Impacts of Flipped Classroom in High School Health Education

    Science.gov (United States)

    Chen, Li-Ling

    2016-01-01

    As advanced technology increasingly infiltrated into classroom, the flipped classroom has come to light in secondary educational settings. The flipped classroom is a new instructional approach that intends to flip the traditional teacher-centered classroom into student centered. The purpose of this research is to investigate the impact of the…

  4. Deep Exploration of the Flipped Classroom before Implementing

    Science.gov (United States)

    Logan, Brenda

    2015-01-01

    This paper is a review of the literature that attempts to explain and document the literature on the flipped classroom. It examines 49 studies that explain the flipped approach in the classroom. This paper, particularly, delineates the history, the theory, benefits, criticisms, recommended practices, and what the research on flipping reveals.…

  5. 产品导向的先进封装设计%Product-Oriented Advanced Packaging Design

    Institute of Scientific and Technical Information of China (English)

    沈文龙; 符会利; 梁立慧; 陈有志; 林志荣; 仲镇华

    2006-01-01

    Cost-effective and reliable electronic packaging has been identified as not only a major driving force but also an enabling technology in today's highly competitive electronics industry, especially for the wireless/portable electronic products which require lighter, smaller form-factors electronic components or modules. In order to meet the demands from the above drivers, microelectronics packaging and interconnect related technologies have evolved from wire bond to flip chip, and eventually to wafer-level chip scale package (WLCSP); from peripheral to area array interconnects; from ceramic to organic substrate materials; and from single chip package to multi-chips system-in-package (SiP).In fact, SiP possesses a number of advantages over conventional packaging and therefore in this study we first present an overview on the recent developments and applications of SiP. It is also necessary to highlight that close co-ordination across the entire supply chain in the electronics industry is the key for prompt SiP implementation. Finally, we put forward to illustrate the critical demands on a centre with integrated packaging design, analysis and characterization capabilities to assist the industries in developingtheir own SiP products targeting for mass production.%在日益激烈竞争的电子工业中,高成本效益、高可靠性的电子封装方案不单是电子产品发展的主要驱动力,甚至往往成为当中的促成科技(Enabling Technology),用于轻巧、细小的无线电/可携带式消费性电子产品中尤见适合.其中更理想的性能效益(cost/performance ratio)、更短的产品开发周期、集多功能于一身的消费性电子产品亦是崭新科技应用的主要原动力.要达到以上目标,相关的微电子封装方案与焊接技术的进步是不可或缺的:例如从金属线焊接技术发展到倒装芯片技术,及至近年的晶圆级封装技术;从外围焊接(peripheral)发展到数组焊接(area-array);从陶制

  6. Blended Course with Flipped Classroom Approach

    DEFF Research Database (Denmark)

    Timcenko, Olga; Purwins, Hendrik; Triantafyllou, Evangelia

    2015-01-01

    This paper presents and analyses design decisions and development process of producing teaching materials for a blended course with flipped classroom approach at bachelor level at Aalborg University in Copenhagen, Denmark. Our experiences, as well as students’ reactions and opinions will be descr......This paper presents and analyses design decisions and development process of producing teaching materials for a blended course with flipped classroom approach at bachelor level at Aalborg University in Copenhagen, Denmark. Our experiences, as well as students’ reactions and opinions...

  7. Revisiting fermion helicity flip in Podolsky's Electromagnetism

    CERN Document Server

    Sales, Jorge Henrique; Thibes, Ronaldo

    2016-01-01

    The spin projection of a massive particle onto its direction of motion is called helicity (or "handedness"). It can therefore be positive or negative. When a particle's helicity changes from positive to negative (or vice-versa) due to its interaction with other particles or fields, we say there is a helicity flip. In this work we show that such helicity flip can be seen for an electron of $20 MeV$ of energy interacting with a charged scalar meson through the exchange of a virtual photon. This photon {\\it does not} necessarily need to be Podolsky's proposed photon; in fact, it is independent of it.

  8. Pixel readout chip for the ATLAS experiment

    CERN Document Server

    Ackers, M; Blanquart, L; Bonzom, V; Comes, G; Fischer, P; Keil, M; Kühl, T; Meuser, S; Delpierre, P A; Treis, J; Raith, B A; Wermes, N

    1999-01-01

    Pixel detectors with a high granularity and a very large number of sensitive elements (cells) are a very recent development used for high precision particle detection. At the Large Hadron Collider LHC at CERN (Geneva) a pixel detector with 1.4*10/sup 8/ individual pixel cells is developed for the ATLAS detector. The concept is a hybrid detector. Consisting of a pixel sensor connected to a pixel electronics chip by bump and flip chip technology in one-to-one cell correspondence. The development and prototype results of the pixel front end chip are presented together with the physical and technical requirements to be met at LHC. Lab measurements are reported. (6 refs).

  9. Portobello Packaging

    National Research Council Canada - National Science Library

    Thomas Grose

    2010-01-01

    ...-based foams. Bayer earned dual degrees in mechanical engineering and product design in 2007 and, with classmate Gavin Mclntyre, started the company Ecovative Design to market his creation. EcoCradle, the company's organic packaging material, was named one of the top inventions of 2009 by Popular Science. Its insulation material, Greensulate, got a ...

  10. CODIMENSION 3 BIFURCATIONS OF HOMOCLINIC ORBITS WITH ORBIT FLIPS AND INCLINATION FLIPS

    Institute of Scientific and Technical Information of China (English)

    SHUI SHULIANG; ZHU DEMING

    2004-01-01

    The homoclinic bifurcations in four dimensional vector fields are investigated by setting up a local coordinates near the homoclinic orbit. This homoclinic orbit is nonprincipal in the meanings that its positive semi-orbit takes orbit flip and its unstable foliation takes inclination flip. The existence, nonexistence, uniqueness and coexistence of the 1-homoclinic orbit and the 1-periodic orbit are studied. The existence of the twofold periodic orbit and three-fold periodic orbit are also obtained.

  11. A Comparative Study of Inspection Techniques for Array Packages

    Science.gov (United States)

    Mohammed, Jelila; Green, Christopher

    2008-01-01

    This viewgraph presentation reviews the inspection techniques for Column Grid Array (CGA) packages. The CGA is a method of chip scale packaging using high temperature solder columns to attach part to board. It is becoming more popular over other techniques (i.e. quad flat pack (QFP) or ball grid array (BGA)). However there are environmental stresses and workmanship challenges that require good inspection techniques for these packages.

  12. Performance and Perception in the Flipped Classroom

    Science.gov (United States)

    Blair, Erik; Maharaj, Chris; Primus, Simone

    2016-01-01

    Changes in the conceptualisation of higher education have led to instructional methods that embrace technology as a teaching medium. These changes have led to the flipped classroom phenomenon--where content is delivered outside class, through media such as video and podcast, and engagement with the content, through problem-solving and/or group…

  13. The Flipped Classroom in World History

    Science.gov (United States)

    Gaughan, Judy E.

    2014-01-01

    The flipped Classroom is one in which lectures are presented as homework outside of class in online videos so that class time is reserved for engaging directly with the materials. This technique offers more personalized guidance and interaction with students, instead of lecturing. In this article, Judy Gaughan details her journey through choosing…

  14. Flipped Classrooms for Advanced Science Courses

    Science.gov (United States)

    Tomory, Annette; Watson, Sunnie Lee

    2015-01-01

    This article explains how issues regarding dual credit and Advanced Placement high school science courses could be mitigated via a flipped classroom instructional model. The need for advanced high school courses will be examined initially, followed by an analysis of advanced science courses and the reform they are experiencing. Finally, it will…

  15. Exploring Flipped Classroom Instruction in Calculus III

    Science.gov (United States)

    Wasserman, Nicholas H.; Quint, Christa; Norris, Scott A.; Carr, Thomas

    2017-01-01

    In an undergraduate Calculus III class, we explore the effect of "flipping" the instructional delivery of content on both student performance and student perceptions. Two instructors collaborated to determine daily lecture notes, assigned the same homework problems, and gave identical exams; however, compared to a more traditional…

  16. 6 Expert Tips for Flipping the Classroom

    Science.gov (United States)

    Demski, Jennifer

    2013-01-01

    In a flipped classroom, professors assign pre-class homework consisting of brief, recorded lectures and presentations, digital readings with collaborative annotation capabilities, and discussion board participation. This frees up classroom time to promote active learning through collaborative, project-based activities using simple display and…

  17. Flip-flopping binary black holes.

    Science.gov (United States)

    Lousto, Carlos O; Healy, James

    2015-04-10

    We study binary spinning black holes to display the long term individual spin dynamics. We perform a full numerical simulation starting at an initial proper separation of d≈25M between equal mass holes and evolve them down to merger for nearly 48 orbits, 3 precession cycles, and half of a flip-flop cycle. The simulation lasts for t=20 000M and displays a total change in the orientation of the spin of one of the black holes from an initial alignment with the orbital angular momentum to a complete antialignment after half of a flip-flop cycle. We compare this evolution with an integration of the 3.5 post-Newtonian equations of motion and spin evolution to show that this process continuously flip flops the spin during the lifetime of the binary until merger. We also provide lower order analytic expressions for the maximum flip-flop angle and frequency. We discuss the effects this dynamics may have on spin growth in accreting binaries and on the observational consequences for galactic and supermassive binary black holes.

  18. Exploring Flipped Classroom Instruction in Calculus III

    Science.gov (United States)

    Wasserman, Nicholas H.; Quint, Christa; Norris, Scott A.; Carr, Thomas

    2017-01-01

    In an undergraduate Calculus III class, we explore the effect of "flipping" the instructional delivery of content on both student performance and student perceptions. Two instructors collaborated to determine daily lecture notes, assigned the same homework problems, and gave identical exams; however, compared to a more traditional…

  19. Flip-OFDM for Unipolar Communication Systems

    CERN Document Server

    Fernando, Nirmal; Viterbo, Emanuele

    2011-01-01

    Unipolar communications systems can transmit information using only real and positive signals. This includes a variety of physical channels ranging from optical (fiber or free-space), to RF wireless using amplitude modulation with non-coherent reception, to baseband single wire communications. Unipolar OFDM techniques enable to efficiently compensate frequency selective distortion in the unipolar communication systems. One of the leading examples of unipolar OFDM is asymmetric clipped optical OFDM (ACO-OFDM) originally proposed for optical communications. Flip-OFDM is an alternative approach that was proposed in a patent, but its performance and full potentials have never been investigated in the literature. In this paper, we first compare Flip-OFDM and ACO-OFDM, and show that both techniques have the same performance but different complexities (Flip-OFDM offers 50% saving). We then propose a new detection scheme, which enables to reduce the noise at the Flip-OFDM receiver by almost 3dB. The analytical perfor...

  20. Flipping an Agricultural Education Teaching Methods Course

    Science.gov (United States)

    Conner, Nathan W.; Stripling, Christopher T.; Blythe, Jessica M.; Roberts, T. Grady; Stedman, Nicole L. P.

    2014-01-01

    Flipping or inverting a course is a relatively new approach to structuring a course. Using this method, the lectures traditionally delivered during regularly scheduled class time are converted to a media for delivery online, often in the form of videos. Learners are expected to view the online lectures prior to class. Then in turn, in-class time…

  1. Using lightboard to flip the course

    DEFF Research Database (Denmark)

    Timcenko, Olga; Triantafyllou, Evangelia; Nilsson, Niels Chr.

    , and exercises for in-class work. However, the quality of videos that students have to watch before coming to the class is also important. In this paper, we will describe videos prepared for flipped classroom using light board, an invention from 2014. That allows natural flow of presentation, as it combines...

  2. Spin flips in generic black hole binaries

    CERN Document Server

    Lousto, Carlos O

    2015-01-01

    We study the spin dynamics of individual black holes in a binary system. In particular we focus on the polar precession of spins and the possibility of a complete flip of spins with respect to the orbital plane. We perform a full numerical simulation that displays these characteristics. We evolve equal mass binary spinning black holes for $t=20,000M$ from an initial proper separation of $d=25M$ down to merger after 48.5 orbits. We compute the gravitational radiation from this system and compare it to 3.5 post-Newtonian generated waveforms finding close agreement. We then further use 3.5 post-Newtonian evolutions to show the extension of this spin {flip-flop} phenomenon to unequal mass binaries. We also provide analytic expressions to approximate the maximum {flip-flop} angle and frequency in terms of the binary spins and mass ratio parameters at a given orbital radius. Finally we discuss the effect this spin {flip-flop} would have on accreting matter and other potential observational effects.

  3. Flip-flops of FK Comae Berenices

    DEFF Research Database (Denmark)

    Hackman, T.; Mantere, M.J.; Jetsu, L.

    2013-01-01

    -2010. The observations were carried out with two automated photometric telescopes, Phoenix-10 and Amadeus T7 located in Arizona. Results. We identify complex phase behaviour in 6 of the 15 analysed data segments. We identify five flip-flop events and two cases of phase jumps, where the phase shift is ¿f

  4. Challenges in the Packaging of MEMS

    Energy Technology Data Exchange (ETDEWEB)

    Malshe, A.P.; Singh, S.B.; Eaton, W.P.; O' Neal, C.; Brown, W.D.; Miller, W.M.

    1999-03-26

    The packaging of Micro-Electro-Mechanical Systems (MEMS) is a field of great importance to anyone using or manufacturing sensors, consumer products, or military applications. Currently much work has been done in the design and fabrication of MEMS devices but insufficient research and few publications have been completed on the packaging of these devices. This is despite the fact that packaging is a very large percentage of the total cost of MEMS devices. The main difference between IC packaging and MEMS packaging is that MEMS packaging is almost always application specific and greatly affected by its environment and packaging techniques such as die handling, die attach processes, and lid sealing. Many of these aspects are directly related to the materials used in the packaging processes. MEMS devices that are functional in wafer form can be rendered inoperable after packaging. MEMS dies must be handled only from the chip sides so features on the top surface are not damaged. This eliminates most current die pick-and-place fixtures. Die attach materials are key to MEMS packaging. Using hard die attach solders can create high stresses in the MEMS devices, which can affect their operation greatly. Low-stress epoxies can be high-outgassing, which can also affect device performance. Also, a low modulus die attach can allow the die to move during ultrasonic wirebonding resulting to low wirebond strength. Another source of residual stress is the lid sealing process. Most MEMS based sensors and devices require a hermetically sealed package. This can be done by parallel seam welding the package lid, but at the cost of further induced stress on the die. Another issue of MEMS packaging is the media compatibility of the packaged device. MEMS unlike ICS often interface with their environment, which could be high pressure or corrosive. The main conclusion we can draw about MEMS packaging is that the package affects the performance and reliability of the MEMS devices. There is a

  5. Challenges in the Packaging of MEMS

    Energy Technology Data Exchange (ETDEWEB)

    Malshe, A.P.; Singh, S.B.; Eaton, W.P.; O' Neal, C.; Brown, W.D.; Miller, W.M.

    1999-03-26

    The packaging of Micro-Electro-Mechanical Systems (MEMS) is a field of great importance to anyone using or manufacturing sensors, consumer products, or military applications. Currently much work has been done in the design and fabrication of MEMS devices but insufficient research and few publications have been completed on the packaging of these devices. This is despite the fact that packaging is a very large percentage of the total cost of MEMS devices. The main difference between IC packaging and MEMS packaging is that MEMS packaging is almost always application specific and greatly affected by its environment and packaging techniques such as die handling, die attach processes, and lid sealing. Many of these aspects are directly related to the materials used in the packaging processes. MEMS devices that are functional in wafer form can be rendered inoperable after packaging. MEMS dies must be handled only from the chip sides so features on the top surface are not damaged. This eliminates most current die pick-and-place fixtures. Die attach materials are key to MEMS packaging. Using hard die attach solders can create high stresses in the MEMS devices, which can affect their operation greatly. Low-stress epoxies can be high-outgassing, which can also affect device performance. Also, a low modulus die attach can allow the die to move during ultrasonic wirebonding resulting to low wirebond strength. Another source of residual stress is the lid sealing process. Most MEMS based sensors and devices require a hermetically sealed package. This can be done by parallel seam welding the package lid, but at the cost of further induced stress on the die. Another issue of MEMS packaging is the media compatibility of the packaged device. MEMS unlike ICS often interface with their environment, which could be high pressure or corrosive. The main conclusion we can draw about MEMS packaging is that the package affects the performance and reliability of the MEMS devices. There is a

  6. Integrated packaging of 2D MOEMS mirrors with optical position feedback

    Science.gov (United States)

    Baumgart, M.; Lenzhofer, M.; Kremer, M. P.; Tortschanoff, A.

    2015-02-01

    Many applications of MOEMS microscanners rely on accurate position feedback. For MOEMS devices which do not have intrinsic on-chip feedback, position information can be provided with optical methods, most simply by using a reflection from the backside of a MOEMS scanner. By measuring the intensity distribution of the reflected beam across a quadrant diode, one can precisely detect the mirror's deflection angles. Previously, we have presented a position sensing device, applicable to arbitrary trajectories, which is based on the measurement of the position of the reflected laser beam with a quadrant diode. In this work, we present a novel setup, which comprises the optical position feedback functionality integrated into the device package itself. The new device's System-in-Package (SiP) design is based on a flip-folded 2.5D PCB layout and fully assembled as small as 9.2×7×4 mm³ in total. The device consists of four layers, which supply the MOEMS mirror, a spacer to provide the required optical path length, the quadrant photo-diode and a laser diode to serve as the light source. In addition to describing the mechanical setup of the novel device, we will present first experimental results and optical simulation studies. Accurate position feedback is the basis for closed-loop control of the MOEMS devices, which is crucial for some applications as image projection for example. Position feedback and the possibility of closed-loop control will significantly improve the performance of these devices.

  7. ChipSeal Inorganic Sealing Technology for Hermetic-Like Integrated Circuits. Volume 1

    Science.gov (United States)

    2000-09-01

    formation (Kerkendall voiding ) and is more susceptible to corrosive attack under adverse conditions. • Degradation of the metallization stack from...processed devices in standard and flip-chip formats, both with and without epoxy encapsulants or underfills . 17 4. Phase I - ChipSeal Process...significant number of bumps exhibited internal voids (Figure 24). A second reflow eliminated the voids open to the surface (Figure 25), but some

  8. Seafood Packaging

    Science.gov (United States)

    1996-01-01

    NASA's Technology Transfer Office at Stennis Space Center worked with a New Orleans seafood packaging company to develop a container to improve the shipping longevity of seafood, primarily frozen and fresh fish, while preserving the taste. A NASA engineer developed metalized heat resistant polybags with thermal foam liners using an enhanced version of the metalized mylar commonly known as 'space blanket material,' which was produced during the Apollo era.

  9. 5GHz LTCC-based aperture coupled wireless transmitter for system-on-package applications

    KAUST Repository

    Shamim, Atif

    2012-01-01

    A novel System-on-Package (SoP) implementation is presented for a transmitter (TX) module which makes use of electromagnetic coupling between the TX chip and the package antenna. The TX chip is realized in 0.13μm CMOS process and comprises an on-chip antenna, which serves as the oscillator\\'s inductor as well. The TX chip is housed in a Low Temperature Co-fired Ceramic (LTCC) package with a patch antenna. The on-chip antenna feeds the LTCC patch antenna through aperture coupling, thus negating the need for RF buffer amplifiers, matching elements, baluns, bond wires and package transmission lines. This is the first ever demonstration of wireless-interconnect between on-chip and package antennas which increases the gain and range of the TX module manyfold with respect to the on-chip antenna alone. Though the range of the TX SoP increases considerably, power consumption remains the same as that of the TX chip only. A simple analytical model for the new wireless-interconnect has been developed which helps determine the optimum position of the chip with respect to the aperture in the ground plane.

  10. Atom chips

    CERN Document Server

    Reichel, Jakob

    2010-01-01

    This book provides a stimulating and multifaceted picture of a rapidly developing field. The first part reviews fundamentals of atom chip research in tutorial style, while subsequent parts focus on the topics of atom-surface interaction, coherence on atom chips, and possible future directions of atom chip research. The articles are written by leading researchers in the field in their characteristic and individual styles.

  11. Packaging Technologies for High Temperature Electronics and Sensors

    Science.gov (United States)

    Chen, Liangyu; Hunter, Gary W.; Neudeck, Philip G.; Beheim, Glenn M.; Spry, David J.; Meredith, Roger D.

    2013-01-01

    This paper reviews ceramic substrates and thick-film metallization based packaging technologies in development for 500degC silicon carbide (SiC) electronics and sensors. Prototype high temperature ceramic chip-level packages and printed circuit boards (PCBs) based on ceramic substrates of aluminum oxide (Al2O3) and aluminum nitride (AlN) have been designed and fabricated. These ceramic substrate-based chiplevel packages with gold (Au) thick-film metallization have been electrically characterized at temperatures up to 550degC. A 96% alumina based edge connector for a PCB level subsystem interconnection has also been demonstrated recently. The 96% alumina packaging system composed of chip-level packages and PCBs has been tested with high temperature SiC devices at 500degC for over 10,000 hours. In addition to tests in a laboratory environment, a SiC JFET with a packaging system composed of a 96% alumina chip-level package and an alumina printed circuit board mounted on a data acquisition circuit board was launched as a part of the MISSE-7 suite to the International Space Station via a Shuttle mission. This packaged SiC transistor was successfully tested in orbit for eighteen months. A spark-plug type sensor package designed for high temperature SiC capacitive pressure sensors was developed. This sensor package combines the high temperature interconnection system with a commercial high temperature high pressure stainless steel seal gland (electrical feed-through). Test results of a packaged high temperature capacitive pressure sensor at 500degC are also discussed. In addition to the pressure sensor package, efforts for packaging high temperature SiC diode-based gas chemical sensors are in process.

  12. Using a SPOC to flip the classroom

    OpenAIRE

    Martínez-Muñoz, Gonzalo; Pulido, Estrella

    2015-01-01

    Personal use of this material is permitted. Permission from IEEE must be obtained for all other uses, in any current or future media, including reprinting/republishing this material for advertising or promotional purposes, creating new collective works, for resale or redistribution to servers or lists, or reuse of any copyrighted component of this work in other works. G. Martínez-Muñoz and E. Pulido, "Using a SPOC to flip the classroom," 2015 IEEE Global Engineering Education Conference (EDUC...

  13. 2-bit Flip Mutation Elementary Fitness Landscapes

    OpenAIRE

    Langdon, William

    2010-01-01

    Genetic Programming parity is not elementary. GP parity cannot be represented as the sum of a small number of elementary landscapes. Statistics, including fitness distance correlation, of Parity's fitness landscape are calculated. Using Walsh analysis the eigen values and eigenvectors of the Laplacian of the two bit flip fitness landscape are given and a ruggedness measure for elementary landscapes is proposed. An elementary needle in a haystack (NIH) landscape is g...

  14. Single Chip Sensing of Multiple Gas Flows

    CERN Document Server

    Bruschi, P; Piotto, M

    2008-01-01

    The fabrication and experimental characterization of a thermal flow meter, capable of detecting and measuring two independent gas flows with a single chip, is described. The device is based on a 4 x 4 mm2 silicon chip, where a series of differential micro-anemometers have been integrated together with standard electronic components by means of postprocessing techniques. The innovative aspect of the sensor is the use of a plastic adapter, thermally bonded to the chip, to convey the gas flow only to the areas where the sensors are located. The use of this inexpensive packaging procedure to include different sensing structures in distinct flow channels is demonstrated.

  15. Assessment of learning gains in a flipped biochemistry classroom.

    Science.gov (United States)

    Ojennus, Deanna Dahlke

    2016-01-01

    The flipped classroom has become an increasingly popular pedagogical approach to teaching and learning. In this study, learning gains were assessed in a flipped biochemistry course and compared to gains in a traditional lecture. Although measured learning gains were not significantly different between the two courses, student perception of learning gains did differ and indicates a higher level of satisfaction with the flipped lecture format. © 2015 The International Union of Biochemistry and Molecular Biology.

  16. Student experiences across multiple flipped courses in a single curriculum.

    Science.gov (United States)

    Khanova, Julia; Roth, Mary T; Rodgers, Jo Ellen; McLaughlin, Jacqueline E

    2015-10-01

    The flipped classroom approach has garnered significant attention in health professions education, which has resulted in calls for curriculum-wide implementations of the model. However, research to support the development of evidence-based guidelines for large-scale flipped classroom implementations is lacking. This study was designed to examine how students experience the flipped classroom model of learning in multiple courses within a single curriculum, as well as to identify specific elements of flipped learning that students perceive as beneficial or challenging. A qualitative analysis of students' comments (n = 6010) from mid-course and end-of-course evaluations of 10 flipped courses (in 2012-2014) was conducted. Common and recurring themes were identified through systematic iterative coding and sorting using the constant comparison method. Multiple coders, agreement through consensus and member checking were utilised to ensure the trustworthiness of findings. Several themes emerged from the analysis: (i) the perceived advantages of flipped learning coupled with concerns about implementation; (ii) the benefits of pre-class learning and factors that negatively affect these benefits, such as quality and quantity of learning materials, as well as overall increase in workload, especially in the context of multiple concurrent flipped courses; (iii) the role of the instructor in the flipped learning environment, particularly in engaging students in active learning and ensuring instructional alignment, and (iv) the need for assessments that emphasise the application of knowledge and critical thinking skills. Analysis of data from 10 flipped courses provided insight into common patterns of student learning experiences specific to the flipped learning model within a single curriculum. The study points to the challenges associated with scaling the implementation of the flipped classroom across multiple courses. Several core elements critical to the effective design

  17. Large area LED package

    Science.gov (United States)

    Goullon, L.; Jordan, R.; Braun, T.; Bauer, J.; Becker, F.; Hutter, M.; Schneider-Ramelow, M.; Lang, K.-D.

    2015-03-01

    Solid state lighting using LED-dies is a rapidly growing market. LED-dies with the needed increasing luminous flux per chip area produce a lot of heat. Therefore an appropriate thermal management is required for general lighting with LEDdies. One way to avoid overheating and shorter lifetime is the use of many small LED-dies on a large area heat sink (down to 70 μm edge length), so that heat can spread into a large area while at the same time light also appears on a larger area. The handling with such small LED-dies is very difficult because they are too small to be picked with common equipment. Therefore a new concept called collective transfer bonding using a temporary carrier chip was developed. A further benefit of this new technology is the high precision assembly as well as the plane parallel assembly of the LED-dies which is necessary for wire bonding. It has been shown that hundred functional LED-dies were transferred and soldered at the same time. After the assembly a cost effective established PCB-technology was applied to produce a large-area light source consisting of many small LED-dies and electrically connected on a PCB-substrate. The top contacts of the LED-dies were realized by laminating an adhesive copper sheet followed by LDI structuring as known from PCB-via-technology. This assembly can be completed by adding converting and light forming optical elements. In summary two technologies based on standard SMD and PCB technology have been developed for panel level LED packaging up to 610x 457 mm2 area size.

  18. ATLAS software packaging

    CERN Document Server

    Rybkin, G

    2012-01-01

    Software packaging is indispensable part of build and prerequisite for deployment processes. Full ATLAS software stack consists of TDAQ, HLT, and Offline software. These software groups depend on some 80 external software packages. We present tools, package PackDist, developed and used to package all this software except for TDAQ project. PackDist is based on and driven by CMT, ATLAS software configuration and build tool, and consists of shell and Python scripts. The packaging unit used is CMT project. Each CMT project is packaged as several packages - platform dependent (one per platform available), source code excluding header files, other platform independent files, documentation, and debug information packages (the last two being built optionally). Packaging can be done recursively to package all the dependencies. The whole set of packages for one software release, distribution kit, also includes configuration packages and contains some 120 packages for one platform. Also packaged are physics analysis pro...

  19. The flipped classroom: practices and opportunities for health sciences librarians.

    Science.gov (United States)

    Youngkin, C Andrew

    2014-01-01

    The "flipped classroom" instructional model is being introduced into medical and health sciences curricula to provide greater efficiency in curriculum delivery and produce greater opportunity for in-depth class discussion and problem solving among participants. As educators employ the flipped classroom to invert curriculum delivery and enhance learning, health sciences librarians are also starting to explore the flipped classroom model for library instruction. This article discusses how academic and health sciences librarians are using the flipped classroom and suggests opportunities for this model to be further explored for library services.

  20. Immunohistopathological Study of c-FLIP Protein in Mycosis Fungoides

    Science.gov (United States)

    Rezk Hassan, Ghada Fawzy; Marey, Karima

    2017-09-27

    Background: Mycosis fungoides (MF) is the commonest variant of primary cutaneous T cell lymphoma with several clinicopathologic variants. Defective apoptotic mechanism may be important in the pathogenesis and progression of MF. c-FLIP protein is an important anti-apoptotic marker and chemotherapeutic resistant factor. This study aimed to evaluate the c-FLIP expression in MF and its role in the pathogenesis of MF. Methods: Twenty patients of MF and ten normal persons were included in this study. Skin biopsies were obtained from both patients and controls. They were studied and examined immunohistochemically for the expression of CD4 and c-FLIP. Results: c-FLIP expression was significantly increased in patients when compared to controls in both epidermis and dermis. There were positive correlations between c-FLIP expression and CD4+ expression in both epidermal and dermal lesions of patients group. There were statistically significant positive correlations between c-FLIP expression (in both dermal and epidermal lesions) and the age of patients. c-FLIP expression increased with the tumor progression but with no statistical significance. Conclusion: Defective regulation of apoptosis has been considered as a main cause for accumulation of clonal T cells, and it was related to an increased expression of c-FLIP which may have a role in the pathogenesis of MF. Also, c-FLIP may have prognostic information in MF as its level increased with both age of the patients and tumor progression. Creative Commons Attribution License

  1. Flip-invariant SIFT for copy and object detection.

    Science.gov (United States)

    Zhao, Wan-Lei; Ngo, Chong-Wah

    2013-03-01

    Scale-invariant feature transform (SIFT) feature has been widely accepted as an effective local keypoint descriptor for its invariance to rotation, scale, and lighting changes in images. However, it is also well known that SIFT, which is derived from directionally sensitive gradient fields, is not flip invariant. In real-world applications, flip or flip-like transformations are commonly observed in images due to artificial flipping, opposite capturing viewpoint, or symmetric patterns of objects. This paper proposes a new descriptor, named flip-invariant SIFT (or F-SIFT), that preserves the original properties of SIFT while being tolerant to flips. F-SIFT starts by estimating the dominant curl of a local patch and then geometrically normalizes the patch by flipping before the computation of SIFT. We demonstrate the power of F-SIFT on three tasks: large-scale video copy detection, object recognition, and detection. In copy detection, a framework, which smartly indices the flip properties of F-SIFT for rapid filtering and weak geometric checking, is proposed. F-SIFT not only significantly improves the detection accuracy of SIFT, but also leads to a more than 50% savings in computational cost. In object recognition, we demonstrate the superiority of F-SIFT in dealing with flip transformation by comparing it to seven other descriptors. In object detection, we further show the ability of F-SIFT in describing symmetric objects. Consistent improvement across different kinds of keypoint detectors is observed for F-SIFT over the original SIFT.

  2. Mapping of low flip angles in magnetic resonance

    Energy Technology Data Exchange (ETDEWEB)

    Balezeau, Fabien; Saint-Jalmes, Herve [LTSI, INSERM U642, Universite Rennes 1 (France); Eliat, Pierre-Antoine [PRISM, IFR 140, Universite Rennes 1 (France); Cayamo, Alejandro Bordelois, E-mail: fabien.balezeau@gmail.com [Centro De BiofIsika Medica, Universidad de Oriente, Santiago de Cuba (Cuba)

    2011-10-21

    Errors in the flip angle have to be corrected in many magnetic resonance imaging applications, especially for T1 quantification. However, the existing methods of B1 mapping fail to measure lower values of the flip angle despite the fact that these are extensively used in dynamic acquisition and 3D imaging. In this study, the nonlinearity of the radiofrequency (RF) transmit chain, especially for very low flip angles, is investigated and a simple method is proposed to accurately determine both the gain of the RF transmitter and the B1 field map for low flip angles. The method makes use of the spoiled gradient echo sequence with long repetition time (TR), such as applied in the double-angle method. It uses an image acquired with a flip angle of 90{sup 0} as a reference image that is robust to B1 inhomogeneity. The ratio of the image at flip angle alpha to the image at a flip angle of 90{sup 0} enables us to calculate the actual value of alpha. This study was carried out at 1.5 and 4.7 T, showing that the linearity of the RF supply system is highly dependent on the hardware. The method proposed here allows us to measure the flip angle from 1{sup 0} to 60{sup 0} with a maximal uncertainty of 10% and to correct T1 maps based on the variable flip angle method.

  3. Flipped classroom model for learning evidence-based medicine

    National Research Council Canada - National Science Library

    Rucker SY; Ozdogan Z; Al Achkar M

    2017-01-01

    .... A flipped classroom model appears to be an ideal strategy to meet the demands to connect evidence to practice while creating engaged, culturally competent, and technologically literate physicians...

  4. High Temperature Pt/Alumina Co-Fired System for 500 C Electronic Packaging Applications

    Science.gov (United States)

    Chen, Liang-Yu; Neudeck, Philip G.; Spry, David J.; Beheim, Glenn M.; Hunter, Gary W.

    2015-01-01

    Gold thick-film metallization and 96 alumina substrate based prototype packaging system developed for 500C SiC electronics and sensors is briefly reviewed, the needs of improvement are discussed. A high temperature co-fired alumina material system based packaging system composed of 32-pin chip-level package and printed circuit board is discussed for packaging 500C SiC electronics and sensors.

  5. PACE3 - front-end chip for the CMS Preshower

    CERN Multimedia

    Aspel, Paul

    2003-01-01

    This is PACE3 which is the front-end chip for the CMS Preshower. In fact PACE3 is the combination of two ASICs called Delta3 and PACEAM3. Delta3 is on the left and PACEAM3 is on the right. The two ASICs are bonded together and then packaged within a single 196 pin fpBGA package.

  6. Flip or Flop? Students' Perspectives of a Flipped Lecture in Mathematics

    Science.gov (United States)

    Novak, Julia; Kensington-Miller, Barbara; Evans, Tanya

    2017-01-01

    This paper describes students' perspectives of a one-off flipped lecture in a large undergraduate mathematics service course. The focus was on calculating matrix determinants and was designed specifically to introduce debate and argumentation into a mathematics lecture. The intention was to promote a deeper learning and understanding through…

  7. Status and prospects for phosphor-based white LED packaging

    Institute of Scientific and Technical Information of China (English)

    Zongyuan LIU; Sheng LIU; Kai WANG; Xiaobing LUO

    2009-01-01

    The status and prospects for high-power, phosphor-based white light-emitting diode (LED) pack-aging have been presented. A system view for packaging design is proposed to address packaging issues. Four aspects of packaging are reviewed: optical control, thermal management, reliability and cost. Phosphor materials play the most important role in light extraction and color control. The conformal coating method improves the spatial color distribution (SCD) of LEDs. High refractive index (RI) encapsulants with high transmittance and modified surface morphology can enhance light extraction. Multi-phosphor-based packaging can realize the control of correlated color temperature (CCT) with high color rendering index (CRI). Effective thermal management can dissipate heat rapidly and reduce thermal stress caused by the mismatch of the coefficient of thermal expansion (CTE). Chip-on-board (COB) technology with a multi-layer ceramic substrate is the most promising method for high-power LED packaging. Low junction temperature will improve the reliability and provide longer life. Advanced processes, precise fabrication and careful operation are essential for high reliability LEDs. Cost is one of the biggest obstacles for the penetration of white LEDs into the market for general illumination products. Mass production in terms of CoB, system in packaging (SIP), 3D packaging and wafer level packaging (WLP) can reduce the cost significantly, especially when chip cost is lowered by using a large wafer size.

  8. Light-emitting diode spherical packages: an equation for the light transmission efficiency

    CERN Document Server

    Moreno, Ivan; Avendano-Alejo, Maximino; 10.1364/AO.49.000012

    2011-01-01

    Virtually all light-emitting diodes (LEDs) are encapsulated with a transparent epoxy or silicone-gel. In this paper we analyze the optical efficiency of spherical encapsulants. We develop a quasi-radiometric equation for the light transmission efficiency, which incorporates some ideas of Monte-Carlo ray tracing into the context of radiometry. The approach includes the extended source nature of the LED chip, and the chip radiance distribution. The equation is an explicit function of the size and the refractive index of the package, and also of several chip parameters such as shape, size, radiance, and location inside the package. To illustrate the use of this equation, we analyze several packaging configurations of practical interest; for example, a hemispherical dome with multiple chips, a flat encapsulation as a special case of the spherical package, and approximate calculations of an encapsulant with a photonic crystal LED or with a photonic quasi crystal LED. These calculations are compared with Monte-Carl...

  9. White LED with High Package Extraction Efficiency

    Energy Technology Data Exchange (ETDEWEB)

    Yi Zheng; Matthew Stough

    2008-09-30

    The goal of this project is to develop a high efficiency phosphor converting (white) Light Emitting Diode (pcLED) 1-Watt package through an increase in package extraction efficiency. A transparent/translucent monolithic phosphor is proposed to replace the powdered phosphor to reduce the scattering caused by phosphor particles. Additionally, a multi-layer thin film selectively reflecting filter is proposed between blue LED die and phosphor layer to recover inward yellow emission. At the end of the project we expect to recycle approximately 50% of the unrecovered backward light in current package construction, and develop a pcLED device with 80 lm/W{sub e} using our technology improvements and commercially available chip/package source. The success of the project will benefit luminous efficacy of white LEDs by increasing package extraction efficiency. In most phosphor-converting white LEDs, the white color is obtained by combining a blue LED die (or chip) with a powdered phosphor layer. The phosphor partially absorbs the blue light from the LED die and converts it into a broad green-yellow emission. The mixture of the transmitted blue light and green-yellow light emerging gives white light. There are two major drawbacks for current pcLEDs in terms of package extraction efficiency. The first is light scattering caused by phosphor particles. When the blue photons from the chip strike the phosphor particles, some blue light will be scattered by phosphor particles. Converted yellow emission photons are also scattered. A portion of scattered light is in the backward direction toward the die. The amount of this backward light varies and depends in part on the particle size of phosphors. The other drawback is that yellow emission from phosphor powders is isotropic. Although some backward light can be recovered by the reflector in current LED packages, there is still a portion of backward light that will be absorbed inside the package and further converted to heat. Heat

  10. Students, Parents Give Thumbs-Up to Flipped Classroom

    Science.gov (United States)

    Pearson, George

    2012-01-01

    The Flipped Classroom isn't for everyone, but it's been well received by Math and Biology students and their parents at Okanagan Mission Secondary School (OKM) in Kelowna, B.C., and was strongly supported by the OKM principal, Scott Mclean. As teacher Graham Johnson noted in his personal account of his first year using the Flipped Classroom…

  11. Case Study: Case Studies and the Flipped Classroom

    Science.gov (United States)

    Herreid, Clyde Freeman; Schiller, Nancy A.

    2013-01-01

    This column provides original articles on innovations in case study teaching, assessment of the method, as well as case studies with teaching notes. This month's issue discusses the positive and negative aspects of the "flipped classroom." In the flipped classroom model, what is normally done in class and what is normally done as…

  12. Flipped Classroom Research and Trends from Different Fields of Study

    Science.gov (United States)

    Zainuddin, Zamzami; Halili, Siti Hajar

    2016-01-01

    This paper aims to analyse the trends and contents of flipped classroom research based on 20 articles that report on flipped learning classroom initiatives from 2013-2015. The content analysis was used as a methodology to investigate methodologies, area of studies, technology tools or online platforms, the most frequently used keywords and works…

  13. Flipped Classrooms and Student Learning: Not Just Surface Gains

    Science.gov (United States)

    McLean, Sarah; Attardi, Stefanie M.; Faden, Lisa; Goldszmidt, Mark

    2016-01-01

    The flipped classroom is a relatively new approach to undergraduate teaching in science. This approach repurposes class time to focus on application and discussion; the acquisition of basic concepts and principles is done on the students' own time before class. While current flipped classroom research has focused on student preferences and…

  14. Malaysian Students' Perceptions of Flipped Classroom: A Case Study

    Science.gov (United States)

    Zainuddin, Zamzami; Attaran, Mohammad

    2016-01-01

    The purpose of this study was to evaluate a class in University of Malaya where flipped learning was applied, and to examine students' perceptions and feedback towards flipped classroom. Data were collected using both quantitative and qualitative methods, i.e. survey, focus group and individual interviews. The results indicated that most students…

  15. Case Study: Guidelines for Producing Videos to Accompany Flipped Cases

    Science.gov (United States)

    Prud'homme-Généreux, Annie; Schiller, Nancy A.; Wild, John H.; Herreid, Clyde Freeman

    2017-01-01

    Three years ago, the "National Center for Case Study Teaching in Science" (NCCSTS) was inspired to merge the case study and flipped classroom approaches. The resulting project aimed to create the materials required to teach a flipped course in introductory biology by assigning videos as homework and case studies in the classroom. Three…

  16. Flipping College Algebra: Effects on Student Engagement and Achievement

    Science.gov (United States)

    Ichinose, Cherie; Clinkenbeard, Jennifer

    2016-01-01

    This study compared student engagement and achievement levels between students enrolled in a traditional college algebra lecture course and students enrolled in a "flipped" course. Results showed that students in the flipped class had consistently higher levels of achievement throughout the course than did students in the traditional…

  17. Student Perceptions of the Flipped Classroom in College Algebra

    Science.gov (United States)

    Ogden, Lori

    2015-01-01

    The flipped classroom approach was implemented across three semesters of a College Algebra course. This paper is part of a larger design and development research study and focuses on student perceptions of the flipped classroom teaching approach. Qualitative methodology was used to describe how students perceived the instruction of their College…

  18. Model studies of lipid flip-flop in membranes

    DEFF Research Database (Denmark)

    Parisio, Giulia; Ferrarini, Alberta; Sperotto, Maria Maddalena

    2016-01-01

    for the molecular-level understanding of flip-flop. In this review we present a summary of the state of the art of computational studies of spontaneous flip-flop of phospholipids, sterols and fatty acids. Also, we highlight critical issues and strategies that have been developed to solve them, and what remains...

  19. Flipping the Calculus Classroom: A Cost-Effective Approach

    Science.gov (United States)

    Young, Andrea

    2015-01-01

    This article discusses a cost-effective approach to flipping the calculus classroom. In particular, the emphasis is on low-cost choices, both monetarily and with regards to faculty time, that make the daunting task of flipping a course manageable for a single instructor. Student feedback and overall impressions are also presented.

  20. Flipping a College Calculus Course: A Case Study

    Science.gov (United States)

    Sahin, Alpaslan; Cavlazoglu, Baki; Zeytuncu, Yunus E.

    2015-01-01

    As online videos have become more easily available and more attractive to the new generation of students, and as new student-learning approaches tend to have more technology integration, the flipped classroom model has become very popular. The purpose of this study was to understand college students' views on flipped courses and investigate how…

  1. Flipping the Calculus Classroom: A Cost-Effective Approach

    Science.gov (United States)

    Young, Andrea

    2015-01-01

    This article discusses a cost-effective approach to flipping the calculus classroom. In particular, the emphasis is on low-cost choices, both monetarily and with regards to faculty time, that make the daunting task of flipping a course manageable for a single instructor. Student feedback and overall impressions are also presented.

  2. On Flipping First-Semester Calculus: A Case Study

    Science.gov (United States)

    Petrillo, Joseph

    2016-01-01

    High failure rates in calculus have plagued students, teachers, and administrators for decades, while science, technology, engineering, and mathematics programmes continue to suffer from low enrollments and high attrition. In an effort to affect this reality, some educators are "flipping" (or inverting) their classrooms. By flipping, we…

  3. On Flipping First-Semester Calculus: A Case Study

    Science.gov (United States)

    Petrillo, Joseph

    2016-01-01

    High failure rates in calculus have plagued students, teachers, and administrators for decades, while science, technology, engineering, and mathematics programmes continue to suffer from low enrollments and high attrition. In an effort to affect this reality, some educators are "flipping" (or inverting) their classrooms. By flipping, we…

  4. A Flipped Spoon and Chin Prompt to Increase Mouth Clean

    Science.gov (United States)

    Dempsey, Jack; Piazza, Cathleen C.; Groff, Rebecca A.; Kozisek, Jennifer M.

    2011-01-01

    We treated the liquid refusal of a 15-month-old girl using 2 antecedent manipulations: flipped spoon and chin prompt. Use of the chin prompt in the absence of the flipped spoon failed to produce increases in mouth clean (a product measure of swallowing). By contrast, modest increases in mouth clean resulted from the implementation of the flipped…

  5. Flipping to Teach the Conceptual Foundations of Successful Workplace Writing

    Science.gov (United States)

    Campbell, Kim Sydow

    2016-01-01

    Flipping originated in science, technology, engineering, and mathematics fields, where didactic transmission of conceptual knowledge has been the standard pedagogy. Flipping has resulted in additional focus on procedural knowledge within class meetings. This article argues that business and professional writing pedagogy, which already focuses…

  6. Application of Flipped Classroom to Vocational College English Teaching

    Institute of Scientific and Technical Information of China (English)

    宋薇

    2014-01-01

    Unlike traditional teaching method,flipped classroom is a form of blended learning in which students learn content online by watching video lecture,usually at home,and students and teachers discuss and solve questions by more personalized guidance and interaction in class,instead of lecturing.Flipped classroom is very useful to vocational college English teaching.

  7. The Perceived Effects of Flipped Teaching on Knowledge Acquisition

    Science.gov (United States)

    Newman, Galen; Kim, Jun-Hyun; Lee, Ryun Jung; Brown, Brandy A.; Huston, Sharon

    2016-01-01

    Increased demands for technological integration in higher education have resulted in new forms of course instruction. Under a flipped approach, students learn course materials outside the classroom while active learning methods are employed inside. This study focuses on the perceived effects of flipped instruction on knowledge acquisition in…

  8. The Implementation of a Flipped Classroom in Foreign Language Teaching

    Science.gov (United States)

    Basal, Ahmet

    2015-01-01

    Alongside the rise of educational technology, many teachers have been taking gradual but innovative steps to redesign their teaching methods. For example, in flipped learning or a flipped classroom, students watch instructional videos outside the classroom and do assignments or engage in activities inside the classroom. Language teachers are one…

  9. Examining Student Perceptions of Flipping an Agricultural Teaching Methods Course

    Science.gov (United States)

    Conner, Nathan W.; Rubenstein, Eric D.; DiBenedetto, Cathy A.; Stripling, Christopher T.; Roberts, T. Grady; Stedman, Nicole L. P.

    2014-01-01

    To meet the needs of the 21st century student, college instructors have been challenged to transform their classrooms from passive to active, "minds-on" learning environments. This qualitative study examined an active learning approach known as a flipped classroom and sought to explore student perceptions of flipping a teaching methods…

  10. Assessment of Learning Gains in a Flipped Biochemistry Classroom

    Science.gov (United States)

    Ojennus, Deanna Dahlke

    2016-01-01

    The flipped classroom has become an increasingly popular pedagogical approach to teaching and learning. In this study, learning gains were assessed in a flipped biochemistry course and compared to gains in a traditional lecture. Although measured learning gains were not significantly different between the two courses, student perception of…

  11. Gradient Descent Bit Flipping Algorithms for Decoding LDPC Codes

    OpenAIRE

    Wadayama, Tadashi; Nakamura, Keisuke; Yagita, Masayuki; Funahashi, Yuuki; Usami, Shogo; Takumi, Ichi

    2007-01-01

    A novel class of bit-flipping (BF) algorithms for decoding low-density parity-check (LDPC) codes is presented. The proposed algorithms, which are called gradient descent bit flipping (GDBF) algorithms, can be regarded as simplified gradient descent algorithms. Based on gradient descent formulation, the proposed algorithms are naturally derived from a simple non-linear objective function.

  12. Flipping College Algebra: Effects on Student Engagement and Achievement

    Science.gov (United States)

    Ichinose, Cherie; Clinkenbeard, Jennifer

    2016-01-01

    This study compared student engagement and achievement levels between students enrolled in a traditional college algebra lecture course and students enrolled in a "flipped" course. Results showed that students in the flipped class had consistently higher levels of achievement throughout the course than did students in the traditional…

  13. Curriculum Design of a Flipped Classroom to Enhance Haematology Learning

    Science.gov (United States)

    Porcaro, Pauline A.; Jackson, Denise E.; McLaughlin, Patricia M.; O'Malley, Cindy J.

    2016-01-01

    A common trend in higher education is the "flipped" classroom, which facilitates active learning during class. The flipped approach to teaching was instituted in a haematology "major" class and the students' attitudes and preferences for the teaching materials were surveyed. The curriculum design was explicit and involved four…

  14. Assessing the Flipped Classroom in Operations Management: A Pilot Study

    Science.gov (United States)

    Prashar, Anupama

    2015-01-01

    The author delved into the results of a flipped classroom pilot conducted for an operations management course module. It assessed students' perception of a flipped learning environment after making them experience it in real time. The classroom environment was construed using a case research approach and students' perceptions were studied using…

  15. The Flipped Class: Experience in a University Business Communication Course

    Science.gov (United States)

    Sherrow, Tammy; Lang, Brenda; Corbett, Rod

    2016-01-01

    Business, like many other programs in higher education, continues to rely largely on traditional classroom environments. In this article, another approach to teaching and learning, the flipped classroom, is explored. After a review of relevant literature, the authors present their experience with the flipped classroom approach to teaching and…

  16. Using Presentation Software to Flip an Undergraduate Analytical Chemistry Course

    Science.gov (United States)

    Fitzgerald, Neil; Li, Luisa

    2015-01-01

    An undergraduate analytical chemistry course has been adapted to a flipped course format. Course content was provided by video clips, text, graphics, audio, and simple animations organized as concept maps using the cloud-based presentation platform, Prezi. The advantages of using Prezi to present course content in a flipped course format are…

  17. Exploring Flipped Classroom Effects on Second Language Learners' Cognitive Processing

    Science.gov (United States)

    Kim, Jeong-eun; Park, Hyunjin; Jang, Mijung; Nam, Hosung

    2017-01-01

    This study investigated the cognitive effects of the flipped classroom approach in a content-based instructional context by comparing second language learners' discourse in flipped vs. traditional classrooms in terms of (1) participation rate, (2) content of comments, (3) reasoning skills, and (4) interactional patterns. Learners in two intact…

  18. Partially Flipped Linear Algebra: A Team-Based Approach

    Science.gov (United States)

    Carney, Debra; Ormes, Nicholas; Swanson, Rebecca

    2015-01-01

    In this article we describe a partially flipped Introductory Linear Algebra course developed by three faculty members at two different universities. We give motivation for our partially flipped design and describe our implementation in detail. Two main features of our course design are team-developed preview videos and related in-class activities.…

  19. Application of Flipped Classroom to Vocational College English Teaching

    Institute of Scientific and Technical Information of China (English)

    宋薇

    2014-01-01

    Unlike traditional teaching method,flipped classroom is a form of blended learning in which students learn content online by watching video lecture,usually at home,and students and teachers discuss and solve questions by more personalized guidance and interaction in class,instead of lecturing. Flipped classroom is very useful to vocational college English teaching.

  20. The Flipped Class: Experience in a University Business Communication Course

    Science.gov (United States)

    Sherrow, Tammy; Lang, Brenda; Corbett, Rod

    2016-01-01

    Business, like many other programs in higher education, continues to rely largely on traditional classroom environments. In this article, another approach to teaching and learning, the flipped classroom, is explored. After a review of relevant literature, the authors present their experience with the flipped classroom approach to teaching and…

  1. Flipping photons backward: reversed Cherenkov radiation

    Directory of Open Access Journals (Sweden)

    Hongsheng Chen

    2011-01-01

    Full Text Available Charged particles moving faster than light in a medium produce Cherenkov radiation. In traditional, positive index-of-refraction materials this radiation travels forward. Metamaterials, with negative indices of refraction, flip the radiation backward. This readily separates it from the particles, providing higher flexibility in photon manipulation and is useful for particle identification and counting. Here we review recent advances in reversed Cherenkov radiation research, including the first demonstration of backward emission. We also discuss the potential for developing new types of devices, such as ones that pierce invisibility cloaks.

  2. uFlip: Understanding Flash IO Patterns

    DEFF Research Database (Denmark)

    Bouganim, Luc; Jonsson, Bjørn; Bonnet, Philippe

    2009-01-01

    want to establish what kind of IOs should be favored (or avoided) when designing algorithms and architectures for flash-based systems. In this paper, we focus on flash IO patterns, that capture relevant distribution of IOs in time and space, and our goal is to quantify their performance. We define u......FLIP, a benchmark for measuring the response time of flash IO patterns. We also present a benchmarking methodology which takes into account the particular characteristics of flash devices. Finally, we present the results obtained by measuring eleven flash devices, and derive a set of design hints that should drive...

  3. Pass transistor Based Negative Edge Trigged D Flip Flop (PTDFF

    Directory of Open Access Journals (Sweden)

    S. P. Nagamani Bai

    2014-04-01

    Full Text Available In this paper a new technique is proposed based on the comparison between Conventional Transistorized Flipflopand Data transition Look ahead D flip flop here we are checking the working of DLDFF and the conventional D Flip-flop after that we are analyzing the characteristic comparison using power & area constraints after that we are proposing a Negative Edge triggered flip-flop named as Passtransistor based negative edge trigged D Flip Flop(PTDFF with reduced number of transistors which will reduce the overall power area as well as delay. The simulations are done using Microwind& DSCH analysis software tools and the result between all those types are listed below. Our proposed system simulations are done under 50nm technology and the results are tabulated below. In that our proposed system is showing better output than the other flip-flops compared here.

  4. Study on localized induction heating for wafer level packaging

    Institute of Scientific and Technical Information of China (English)

    2010-01-01

    Micro-electro-mechanical systems(MEMS)are being developed as a new multi-disciplinary technology,which will undoubtedly have a revolutionary impact on the future of human life.However,with the development of MEMS technology,the packaging has become the main technical obstacle to the commercialization of MEMS.An approach to MEMS packaging by high-frequency electromagnetic induction heating at wafer level is presented in terms of numerical simulation and experimental study.The structure of inductor is firstly designed and optimized.Then the heating situation of PCB board is verified.The results indicate that the heat impact on the chip during the packaging process can be effectively reduced by local induction heating packaging,therefore the thermal stress on the chip is considerably lowered.This method can effectively improve the reliability of the MEMS devices.

  5. A Quasi Experiment to Determine the Effectiveness of a "Partially Flipped" versus "Fully Flipped" Undergraduate Class in Genetics and Evolution

    Science.gov (United States)

    Adams, Alison E. M.; Garcia, Jocelyn; Traustadóttir, Tinna

    2016-01-01

    Two sections of Genetics and Evolution were taught by one instructor. One group (the fully flipped section) had the entire class period devoted to active learning (with background material that had to be watched before class), and the other group (the partially flipped section) had just a portion of class time spent on active learning (with the…

  6. Application of Flipped Classroom in English Majors' Grammar Teaching%Application of Flipped Classroom in English Majors'Grammar Teaching

    Institute of Scientific and Technical Information of China (English)

    滕丽梅

    2016-01-01

    This paper analyzed how flipped classroom facilitated grammar teaching for English majors by indicating the principle status of students in class, shaping good classroom atmosphere of grammar learning and expanding English grammar teaching. Meanwhile, it raised strategies of flipped classroom applied in English majors' grammar teaching such as preparations before class and abundant teaching methods.

  7. Observations of Langmuir Circulation From FLIP

    Science.gov (United States)

    Smith, J. A.

    2002-12-01

    Langmuir circulation has significance across the marine disciplines. Enhanced deepening and inhibited re-stratification can alter the surface temperature and hence net air-sea exchanges. Organization of bubbles into windrows introduces dramatic sound speed variability and also affects air/sea gas fluxes. Organization of seaweed and plankton affects marine life, including pelagic fisheries. Finally, dispersal by Langmuir circulation is a major component in models for oil-spill tracking and for search-and-rescue operations. To get an adequate picture of the forcing and response of Langmuir circulation (and the wind-mixed layer in general), the observations needed include windstress, directional waves, wave breaking, heat and moisture fluxes, stratification (temperature and salinity profiles), velocity profiles across the mixed layer and thermocline, spacing and orientation of windrows, and a measure of the strength of the circulation (e.g., surface rms velocities). These measurements span both the air/sea interface and the thermocline, and must be maintained continuously for many days to span storms and daily, tidal, and inertial cycles. In addition, the total power requirements exceed that comfortably supplied by batteries or local generation by wind or solar energy. It appears that FLIP is uniquely qualified as a platform from which the required range of measurements may all be made. Findings concerning the evolution and dynamics of Langmuir circulation that were facilitated by FLIP are reviewed and summarized, with emphasis on observations from 1990, 1995, and 2002.

  8. Flipped models in Trinification: A Comprehensive Approach

    CERN Document Server

    Rodríguez, Oscar; Ponce, William A; Rojas, Eduardo

    2016-01-01

    By considering the 3-3-1 and the left-right symmetric models as low energy effective theories of the trinification group, alternative versions of these models are found. The new neutral gauge bosons in the universal 3-3-1 model and its flipped versions are considered; also, the left-right symmetric model and the two flipped variants of it are also studied. For these models, the couplings of the $Z'$ bosons to the standard model fermions are reported. The explicit form of the null space of the vector boson mass matrix for an arbitrary Higgs tensor and gauge group is also presented. In the general framework of the trinification gauge group, and by using the LHC experimental results and EW precision data, limits on the $Z'$ mass and the mixing angle between $Z$ and the new gauge bosons $Z'$ are imposed. The general results call for very small mixing angles in the range $10^{-3}$ radians and $M_{Z'}$ > 2.5 TeV.

  9. Perceptions of Senior-Year ELT Students for Flipped Classroom: A Materials Development Course

    Science.gov (United States)

    Adnan, Müge

    2017-01-01

    This paper describes a structured attempt to integrate the flipped classroom model into a senior-level course at the higher education level. This study's purpose is to examine and compare the impact of flipped classrooms versus non-flipped as a means to contribute to the growing line of research on flipped teaching through an evaluation of both…

  10. Chips 2020

    CERN Document Server

    2016-01-01

    The release of this second volume of CHIPS 2020 coincides with the 50th anniversary of Moore’s Law, a critical year marked by the end of the nanometer roadmap and by a significantly reduced annual rise in chip performance. At the same time, we are witnessing a data explosion in the Internet, which is consuming 40% more electrical power every year, leading to fears of a major blackout of the Internet by 2020. The messages of the first CHIPS 2020, published in 2012, concerned the realization of quantum steps for improving the energy efficiency of all chip functions. With this second volume, we review these messages and amplify upon the most promising directions: ultra-low-voltage electronics, nanoscale monolithic 3D integration, relevant-data, brain- and human-vision-inspired processing, and energy harvesting for chip autonomy. The team of authors, enlarged by more world leaders in low-power, monolithic 3D, video, and Silicon brains, presents new vistas in nanoelectronics, promising  Moore-like exponential g...

  11. Studenters erfaringer med Flipped Classroom i en helsefagutdanning

    Directory of Open Access Journals (Sweden)

    Christine Tørris

    2015-12-01

    Full Text Available Background: The flipped classroom approach has gained increased attention in educational research literature. The purpose of this study was to investigate how students experience a flipped classroom approach in health education, compared to ordinary lectures. Method: Bachelor students (n=25 who watched the video-based material in the flipped classrooms pre-session, answered a questionnaire to evaluate their flipped classroom experience. The questionnaire consisted of both closed and open questions. Results: Ninety six per cent (24/25 of respondents found the video-based material in the pre-session useful. Seventy six per cent (19/25 of respondents found that the flipped classroom approach resulted in the highest learning outcome, over the traditional approach (16%, 4/25. Barriers to the flipped classroom approach was technical problems with the video-based material, such as screen view. Conclusion: The flipped classroom approach is promising as an acceptable approach for teaching in health science curricular in higher education.

  12. Magnetic flipping - Reconnection in three dimensions without null points

    Science.gov (United States)

    Priest, E. R.; Forbes, T. G.

    1992-01-01

    In three dimensions, magnetic reconnection may take place in a sheared magnetic field at any singular field line, where the nearby field has X-type topology in planes perpendicular to the field line and where an electric field is present parallel to the field line. In the ideal region around the singular line there will, in general, be singularities in the plasma flow and electric field, both at the singular line and at 'magnetic flipping layers', which are remnants of local magnetic separatrices. In the absence of a three-dimensional magnetic neutral point or null point, reconnection of field lines can still occur by a process of magnetic flipping, in which the plasma crosses the flipping layers but the field lines rapidly flip along them by magnetic diffusion. Depending on the boundary conditions, there may be two or four flipping layers which converge on the singular line. A boundary layer analysis of a flipping layer is given, in which the magnetic field parallel to the layer decreases as one crosses it while the plasma pressure (or magnetic pressure associated with the field along the singular line) increases. The width of the flipping layer decreases with distance from the singular line.

  13. Magnetic flipping: Reconnection in three-dimensions without null points

    Energy Technology Data Exchange (ETDEWEB)

    Priest, E.R.; Forbes, T.G. (Univ. of New Hampshire, Durham (United States))

    1992-02-01

    In three dimensions, magnetic reconnection may take place in a sheared magnetic field at any singular field line, where the nearby field has X-type topology in planes perpendicular to the field line and where an electric field is present parallel to the field line. In the ideal region around the singular line there will, in general, be singularities in the plasma flow and electric field, both at the singular line and at magnetic flipping layers, which are remnants of local magnetic separatrices. In the absence of a three-dimensional magnetic point or null point, reconnection of field lines can still occur by a process of magnetic flipping, in which the plasma crosses the flipping layers but the field lines rapidly flip along them by magnetic diffusion. Depending on the boundary conditions, there may be two or four flipping layers which converge on the singular line. A boundary layer analysis of a flipping layer is given, in which the magnetic field parallel to the layer decreases as one crosses it while the plasma pressure (or magnetic pressure associated with the field along the singular line) increases. The width of the flipping layer decreases with distance from the singular line.

  14. Studenters erfaringer med Flipped Classroom i en helsefagutdanning

    Directory of Open Access Journals (Sweden)

    Christine Tørris

    2015-12-01

    Full Text Available Background: The flipped classroom approach has gained increased attention in educational research literature. The purpose of this study was to investigate how students experience a flipped classroom approach in health education, compared to ordinary lectures. Method: Bachelor students (n=25 who watched the video-based material in the flipped classrooms pre-session, answered a questionnaire to evaluate their flipped classroom experience. The questionnaire consisted of both closed and open questions. Results: Ninety six per cent (24/25 of respondents found the video-based material in the pre-session useful. Seventy six per cent (19/25 of respondents found that the flipped classroom approach resulted in the highest learning outcome, over the traditional approach (16%, 4/25. Barriers to the flipped classroom approach was technical problems with the video-based material, such as screen view. Conclusion: The flipped classroom approach is promising as an acceptable approach for teaching in health science curricular in higher education.

  15. The Phenomenology of Flipped SU(5)

    Science.gov (United States)

    Abel, S. A.

    1990-01-01

    Available from UMI in association with The British Library. In this thesis, I examine the phenomenology of the supersymmetric flipped SU(5) model. Such a model has been derived as a low energy approximation to heterotic string theory, probably with a 'no-scale' supersymmetry breaking mechanism. It is found that a large region of the flipped SU(5) parameter space predicts a satisfactory breaking down to the standard model on renormalization down to low energies. In particular it contains a number of phenomenological advantages over other GUT schemes, such as a natural Higg's doublet-triplet mass splitting, and a neutrino see-saw mechanism. Analysis of the neutrino sector shows that this model may allow rapid decays of the heavy neutrinos into lighter electron-neutrinos. This is due to new flavour changing couplings in the superpotential, which are included in the neutrino mass matrix. Such fast decays may be able to evade certain cosmological bounds, based on the standard inflationary scenarios and the observation of the 3K background radiation. Thus it is possible that neutrinos could form a substantial proportion of the dark matter in the Universe. Rare processes may be significantly enhanced in the flipped SU(5) scenario, due to new couplings whose off diagonal Kobayashi-Maskawa matrix elements need not be small. In particular, the gaugino-fermion-sfermion coupling may give important new flavour changing diagrams, since, after supersymmetry is broken, the fermions and sfermions are no longer simultaneously diagonalizable. This leads to the possibility of decays such as Z to bs and muto egamma being detected in the near future. In addition to this there are significant new contributions to the electric dipole moment of the neutron which may be as high as the present day limit of | d_ n| < 10^{-25}ecm. Support for this model may come from neutralino contributions to the number of 'neutrino species' measured in Z decays. Finally, the anomalous magnetic moment of the

  16. Research, Perspectives, and Recommendations on Implementing the Flipped Classroom.

    Science.gov (United States)

    Rotellar, Cristina; Cain, Jeff

    2016-03-25

    Flipped or inverted classrooms have become increasingly popular, and sometimes controversial, within higher education. Many educators have touted the potential benefits of this model and initial research regarding implementation has been primarily positive. The rationale behind the flipped classroom methodology is to increase student engagement with content, increase and improve faculty contact time with students, and enhance learning. This paper presents a summary of primary literature regarding flipped classrooms, discusses concerns and unanswered questions from both a student and faculty member perspective, and offers recommendations regarding implementation.

  17. Integral Optimization of Systematic Parameters of Flip-Flow Screens

    Institute of Scientific and Technical Information of China (English)

    翟宏新

    2004-01-01

    The synthetic index Ks for evaluating flip-flow screens is proposed and systematically optimized in view of the whole system. A series of optimized values of relevant parameters are found and then compared with those of the current industrial specifications. The results show that the optimized value Ks approaches the one of those famous flip-flow screens in the world. Some new findings on geometric and kinematics parameters are useful for improving the flip-flow screens with a low Ks value, which is helpful in developing clean coal technology.

  18. Polarizing a stored proton beam by spin flip?

    CERN Document Server

    Oellers, D; Barsov, S; Bechstedt, U; Benati, P; Bertelli, S; Chiladze, D; Ciullo, G; Contalbrigo, M; Dalpiaz, P F; Dietrich, J; Dolfus, N; Dymov, S; Engels, R; Erven, W; Garishvili, A; Gebel, R; Goslawski, P; Grigoryev, K; Hadamek, H; Kacharava, A; Khoukaz, A; Kulikov, A; Langenberg, G; Lehrach, A; Lenisa, P; Lomidze, N; Lorentz, B; Macharashvili, G; Maier, R; Martin, S; Merzliakov, S; Meshkov, I N; Meyer, H O; Mielke, M; Mikirtychiants, M; Mikirtychiants, S; Nass, A; Nekipelov, M; Nikolaev, N N; Nioradze, M; d'Orsaneo, G; Papenbrock, M; Prasuhn, D; Rathmann, F; Sarkadi, J; Schleichert, R; Smirnov, A; Seyfarth, H; Sowinski, J; Spoelgen, D; Stancari, G; Stancari, M; Statera, M; Steffens, E; Stein, H J; Stockhorst, H; Straatmann, H; Ströher, H; Tabidze, M; Tagliente, G; Engblom, P Thoerngren; Trusov, S; Vasilyev, A; Weidemann, Chr; Welsch, D; Wieder, P; Wüstner, P; Zupranski, P

    2009-01-01

    We discuss polarizing a proton beam in a storage ring, either by selective removal or by spin flip of the stored ions. Prompted by recent, conflicting calculations, we have carried out a measurement of the spin flip cross section in low-energy electron-proton scattering. The experiment uses the cooling electron beam at COSY as an electron target. The measured cross sections are too small for making spin flip a viable tool in polarizing a stored beam. This invalidates a recent proposal to use co-moving polarized positrons to polarize a stored antiproton beam.

  19. Introducing a Flipped Classroom for a Statistics Course

    DEFF Research Database (Denmark)

    Triantafyllou, Eva; Timcenko, Olga

    2014-01-01

    One of the novel ideas in teaching that heavily relies on current technology is the “flipped classroom” approach, or “inverse teaching”. In a flipped classroom the traditional lecture and homework sessions are inverted. Students are provided with online material in order to gain necessary knowledge...... students in a Bachelor program in Media Technology. The results of the experiment revealed some strengths and weaknesses of this instructional model. We conclude that the flipped classroom can be beneficial for students, provided that it is based on a careful design....

  20. Assisted crack tip flipping under Mode I thin sheet tearing

    DEFF Research Database (Denmark)

    Felter, Christian Lotz; Nielsen, Kim Lau

    2017-01-01

    such as slanting, cup-cone (rooftop), or cup-cup (bathtub) the flipping crack never settles in a steady-state as the near tip stress/strain field continuously change when the flip successively initiates and develops shear-lips. A recent experimental investigation has revealed new insight by exploiting 3D X...... type loading) on the tip of a slant Mode I crack can provoke it to flip to the opposite side. Both experiments and micro-mechanics based modeling support this hypothesis....

  1. Operation and Maintenance of the Research Platform FLIP

    Science.gov (United States)

    2015-07-01

    operate safety in sup^urt uf uNk fcSedieh. \\ uiiJin^ ficts also cuveieJ the cust uf a ruutlnc dry docking of FLIP in 2013. Dry dockings occur at 3...support of ONR research. ONR funding has also covered the cost of an 18 June to 18 July 2013 routine dry docking , of FLIP. Dry dockings occur at a 3-year...18 July 2013, FLIP underwent a routine dry dockings in the navy floating dry dock USS ARCO ARDM 5 at the Naval Base Point Loma, San Diego. Routine

  2. [Flipped classroom in basic medical education].

    Science.gov (United States)

    Merenmies, Jussi; Niemi-Murola, Leila; Pyörälä, Eeva

    2015-01-01

    Medical education is facing changes in order to improve young doctors' competency to respond better to current needs of the patients and the society. Both curriculum content and teaching methods are revised. In addition to vibrant research in academic medical education, teachers are supported by the improved web-based learning environments and novel technical tools. Flipped classroom, a new paradigm that benefits from technical development, provides many opportunities for medical education. This teaching method always consists of two mutually complementary parts. The first part of the learning action takes place independently off classroom with video lectures or other stimuli for learning. The second part takes place in conjunction with the teacher and other students, and requires student group interactions.

  3. Front propagation and rejuvenation in flipping processes

    Energy Technology Data Exchange (ETDEWEB)

    Ben-naim, Eli [Los Alamos National Laboratory; Krapivsky, P I [BOSTON UNIV; Antal, T [HARVARD UNIV; Ben - Avrahm, D [HARVARD UNIV

    2008-01-01

    We study a directed flipping process that underlies the performance of the random edge simplex algorithm. In this stochastic process, which takes place on a one-dimensional lattice whose sites may be either occupied or vacant, occupied sites become vacant at a constant rate and simultaneously cause all sites to the right to change their state. This random process exhibits rich phenomenology. First, there is a front, defined by the position of the leftmost occupied site, that propagates at a nontrivial velocity. Second, the front involves a depletion zone with an excess of vacant sites. The total excess {Delta}{sub k} increases logarithmically, {Delta}{sub k} {approx_equal}ln k, with the distance k from the front. Third, the front exhibits ageing -- young fronts are vigorous but old fronts are sluggish. We investigate these phenomena using a quasi-static approximation, direct solutions of small systems and numerical simulations.

  4. Bridging the gap with flipped classroom

    DEFF Research Database (Denmark)

    Selberg, Hanne; Topperzer, Martha

    2016-01-01

    using educational technologies such as online preparation contents and simulation based scenarios. Furthermore, the objective is to enhance theory-practice integration in the educational setting. Materials & Methods The flipped classroom model replaces three theoretical lectures addressing disease...... are designed according to Dieckmann´s model (2009) consisting of a pre-briefing with the possibility to reflect on and clarify uncertainties relating to theory and physiology relating to the simulation themes, which are then followed by setting intro, simulator briefing, scenarios and debriefing...... • Challenges the students´ performance • Facilitates an enhanced level of reflection and engagement in debriefing • The concept allows theoretical knowledge to be translated into practical application • The theory-practice integration enhances the learning outcome and helps memorize the content • Applying...

  5. Packaging Aspects of Photodetector Modules for 100 Gbit/s Ethernet Applications

    DEFF Research Database (Denmark)

    Jiang, Chenhui; Mekonnen, G.G.; Krozer, Viktor;

    2008-01-01

    Packaging is a major problem at millimetre-wave frequencies approaching 100 GHz. In this paper we present that insertion losses in a multi-chip module (MCM) can be less IL <0.6 dB at 100 GHz. The paper also analyzes in detail resonance modes in the packages. The characteristic of conductor-backed...

  6. High curvature bending characterization of ultra-thin chips and chip-on-foil assemblies

    NARCIS (Netherlands)

    Ende, D. van den; Verhoeven, F.; Eijnden, P. van der; Kusters, R.; Sridhar, A.; Cauwe, M.; Brand, J. van den

    2013-01-01

    Ultra-thin chips of less than 20μm become flexible, allowing integration of silicon IC technology with highly flexible electronics. This combination allows for highly intelligent products of unprecedented thinness, flexibility and cost. Examples include sensor systems integrated into food packaging

  7. High curvature bending characterization of ultra-thin chips and chip-on-foil assemblies

    NARCIS (Netherlands)

    Ende, D. van den; Verhoeven, F.; Eijnden, P. van der; Kusters, R.; Sridhar, A.; Cauwe, M.; Brand, J. van den

    2013-01-01

    Ultra-thin chips of less than 20μm become flexible, allowing integration of silicon IC technology with highly flexible electronics. This combination allows for highly intelligent products of unprecedented thinness, flexibility and cost. Examples include sensor systems integrated into food packaging

  8. Lithographic chip identification: meeting the failure analysis challenge

    Science.gov (United States)

    Perkins, Lynn; Riddell, Kevin G.; Flack, Warren W.

    1992-06-01

    This paper describes a novel method using stepper photolithography to uniquely identify individual chips for permanent traceability. A commercially available 1X stepper is used to mark chips with an identifier or `serial number' which can be encoded with relevant information for the integrated circuit manufacturer. The permanent identification of individual chips can improve current methods of quality control, failure analysis, and inventory control. The need for this technology is escalating as manufacturers seek to provide six sigma quality control for their products and trace fabrication problems to their source. This need is especially acute for parts that fail after packaging and are returned to the manufacturer for analysis. Using this novel approach, failure analysis data can be tied back to a particular batch, wafer, or even a position within a wafer. Process control can be enhanced by identifying the root cause of chip failures. Chip identification also addresses manufacturers concerns with increasing incidences of chip theft. Since chips currently carry no identification other than the manufacturer's name and part number, recovery efforts are hampered by the inability to determine the sales history of a specific packaged chip. A definitive identifier or serial number for each chip would address this concern. The results of chip identification (patent pending) are easily viewed through a low power microscope. Batch number, wafer number, exposure step, and chip location within the exposure step can be recorded, as can dates and other items of interest. An explanation of the chip identification procedure and processing requirements are described. Experimental testing and results are presented, and potential applications are discussed.

  9. Flipping the classroom to improve student performance and satisfaction.

    Science.gov (United States)

    Missildine, Kathy; Fountain, Rebecca; Summers, Lynn; Gosselin, Kevin

    2013-10-01

    This study aimed to determine the effects of a flipped classroom (i.e., reversal of time allotment for lecture and homework) and innovative learning activities on academic success and the satisfaction of nursing students. A quasi-experimental design was used to compare three approaches to learning: traditional lecture only (LO), lecture and lecture capture back-up (LLC), and the flipped classroom approach of lecture capture with innovative classroom activities (LCI). Examination scores were higher for the flipped classroom LCI group (M = 81.89, SD = 5.02) than for both the LLC group (M = 80.70, SD = 4.25), p = 0.003, and the LO group (M = 79.79, SD = 4.51), p flipped classroom method than with either of the other methods (p classroom activities can result in improved learning but not necessarily improved student satisfaction.

  10. Evaluation of a Flipped Drug Literature Evaluation Course.

    Science.gov (United States)

    Giuliano, Christopher Alan; Moser, Lynette R

    2016-05-25

    Objective. To evaluate a flipped drug literature evaluation course for first-year pharmacy students. Design. A drug literature evaluation course was flipped during the 2014 winter semester. Homework from 2013 was transformed into activities and lectures were transformed into multiple short YouTube videos. Assessment. Average examination scores increased from 75.6% to 86.1%. Eighty-two of 94 students completed the postcourse survey in 2014. Compared to traditional lecture, 59.8% of students indicated they preferred the flipped course. Additionally, students felt the course was important, the in-class activities were helpful, and some of the YouTube videos could be improved. We found length of the video to be significantly correlated with the percentage of videos viewed. Conclusion. The flipped model should be considered in drug literature evaluation courses that seek to increase the amount of active learning in the classroom.

  11. What millennial medical students say about flipped learning.

    Science.gov (United States)

    Pettit, Robin K; McCoy, Lise; Kinney, Marjorie

    2017-01-01

    Flipped instruction is gaining popularity in medical schools, but there are unanswered questions such as the optimum amount of the curriculum to flip and whether flipped sessions should be mandatory. We were in a unique position to evaluate feedback from first-year medical students who had experienced both flipped and lecture-based courses during their first semester of medical school. A key finding was that the students preferred a variety of different learning formats over an "all or nothing" learning format. Learning format preferences did not necessarily align with perceptions of which format led to better course exam performance. Nearly 70% of respondents wanted to make their own decisions regarding attendance. Candid responses to open-ended survey prompts reflected millennial preferences for choice, flexibility, efficiency, and the ability to control the pace of their learning, providing insight to guide curricular improvements.

  12. Online Learning Room for ”Flipped Classroom”

    DEFF Research Database (Denmark)

    Bugge, Ellen Margrethe; Nielsen, Linda Susanna Hauschildt

    2014-01-01

    working actively and innovatively to create a didactic design in our online learning rooms in our LMS that satisfy the demands for flipped learning and at the same time adapted to the special needs of each learning module at the nursing education programme. Keywords: Online learning, flipped classroom......Abstract The “flipped classroom” learning concept is an alternative way of teaching & learning. The fundamental idea of the "flipped classroom" is to change the way students prepare for classes and the work that takes place when the students are together in the classroom. This integrates online...... learning with learning in the classroom. The learning room must support the students’ unassisted learning, their preparation for class and their preparation for supervision in both a motivating and clear way. At the Nursing Education Programme at University College Lillebaelt in Denmark, we have been...

  13. Flipped classroom model for learning evidence-based medicine.

    Science.gov (United States)

    Rucker, Sydney Y; Ozdogan, Zulfukar; Al Achkar, Morhaf

    2017-01-01

    Journal club (JC), as a pedagogical strategy, has long been used in graduate medical education (GME). As evidence-based medicine (EBM) becomes a mainstay in GME, traditional models of JC present a number of insufficiencies and call for novel models of instruction. A flipped classroom model appears to be an ideal strategy to meet the demands to connect evidence to practice while creating engaged, culturally competent, and technologically literate physicians. In this article, we describe a novel model of flipped classroom in JC. We present the flow of learning activities during the online and face-to-face instruction, and then we highlight specific considerations for implementing a flipped classroom model. We show that implementing a flipped classroom model to teach EBM in a residency program not only is possible but also may constitute improved learning opportunity for residents. Follow-up work is needed to evaluate the effectiveness of this model on both learning and clinical practice.

  14. What millennial medical students say about flipped learning

    Science.gov (United States)

    Pettit, Robin K; McCoy, Lise; Kinney, Marjorie

    2017-01-01

    Flipped instruction is gaining popularity in medical schools, but there are unanswered questions such as the optimum amount of the curriculum to flip and whether flipped sessions should be mandatory. We were in a unique position to evaluate feedback from first-year medical students who had experienced both flipped and lecture-based courses during their first semester of medical school. A key finding was that the students preferred a variety of different learning formats over an “all or nothing” learning format. Learning format preferences did not necessarily align with perceptions of which format led to better course exam performance. Nearly 70% of respondents wanted to make their own decisions regarding attendance. Candid responses to open-ended survey prompts reflected millennial preferences for choice, flexibility, efficiency, and the ability to control the pace of their learning, providing insight to guide curricular improvements. PMID:28769600

  15. Flipped classroom model for learning evidence-based medicine

    Science.gov (United States)

    Rucker, Sydney Y; Ozdogan, Zulfukar; Al Achkar, Morhaf

    2017-01-01

    Journal club (JC), as a pedagogical strategy, has long been used in graduate medical education (GME). As evidence-based medicine (EBM) becomes a mainstay in GME, traditional models of JC present a number of insufficiencies and call for novel models of instruction. A flipped classroom model appears to be an ideal strategy to meet the demands to connect evidence to practice while creating engaged, culturally competent, and technologically literate physicians. In this article, we describe a novel model of flipped classroom in JC. We present the flow of learning activities during the online and face-to-face instruction, and then we highlight specific considerations for implementing a flipped classroom model. We show that implementing a flipped classroom model to teach EBM in a residency program not only is possible but also may constitute improved learning opportunity for residents. Follow-up work is needed to evaluate the effectiveness of this model on both learning and clinical practice. PMID:28919831

  16. Step to improve neural cryptography against flipping attacks.

    Science.gov (United States)

    Zhou, Jiantao; Xu, Qinzhen; Pei, Wenjiang; He, Zhenya; Szu, Harold

    2004-12-01

    Synchronization of neural networks by mutual learning has been demonstrated to be possible for constructing key exchange protocol over public channel. However, the neural cryptography schemes presented so far are not the securest under regular flipping attack (RFA) and are completely insecure under majority flipping attack (MFA). We propose a scheme by splitting the mutual information and the training process to improve the security of neural cryptosystem against flipping attacks. Both analytical and simulation results show that the success probability of RFA on the proposed scheme can be decreased to the level of brute force attack (BFA) and the success probability of MFA still decays exponentially with the weights' level L. The synchronization time of the parties also remains polynomial with L. Moreover, we analyze the security under an advanced flipping attack.

  17. PENGARUH FLIPPED MASTERY CLASSROM TERHADAP PEROLEHAN HASIL BELAJAR KOGNITIF MAHASISWA

    Directory of Open Access Journals (Sweden)

    Muhammad Ridha

    2016-04-01

    Tujuan dari penelitian ini adalah untuk mengetahui pengaruh penerapan strategi flipped mastery classroom terhadap perolehan hasil belajar kognitif mahasiswa pada matakuliah psikologi pendidikan. Subjek dalam penelitian ini adalah mahasiswa Jurusan Teknologi Pendidikan Universitas Negeri Malang semester genap tahun ajaran 2015/2016 pada kelas utuh. Kelas eksperimen dibelajarkan dengan strategi flipped-mastery classroom dan kelas kontrol dibelajarkan dengan strategi tradisional.  Penelitian ini menggunakan rancangan kuasi eksperimen Non Equivalent Control Group Design. Hasil penelitian menunjukkan bahwa penerapan strategi flipped mastery classroom memberikan pengaruh positif terhadap perolehan hasil belajar kognitif mahasiswa. Perolehan hasil belajar kognitif mahasiswa yang dibelajarkan dengan strategi flipped-mastery lebih tinggi secara signifikan dari pada perolehan hasil belajar mahasiswa yang dibelajarkan dengan strategi tradisional.

  18. Implementing the Flipped Classroom in Teacher Education: Evidence from Turkey

    National Research Council Canada - National Science Library

    Gökçe Kurt

    2017-01-01

    The flipped classroom, a form of blended learning, is an emerging instructional strategy reversing a traditional lecture-based teaching model to improve the quality and efficiency of the teaching and learning process...

  19. Micro packaged MEMS pressure sensor for intracranial pressure measurement

    Science.gov (United States)

    Xiong, Liu; Yan, Yao; Jiahao, Ma; Yanhang, Zhang; Qian, Wang; Zhaohua, Zhang; Tianling, Ren

    2015-06-01

    This paper presents a micro packaged MEMS pressure sensor for intracranial pressure measurement which belongs to BioMEMS. It can be used in lumbar puncture surgery to measure intracranial pressure. Miniaturization is key for lumbar puncture surgery because the sensor must be small enough to allow it be placed in the reagent chamber of the lumbar puncture needle. The size of the sensor is decided by the size of the sensor chip and package. Our sensor chip is based on silicon piezoresistive effect and the size is 400 × 400 μm2. It is much smaller than the reported polymer intracranial pressure sensors such as liquid crystal polymer sensors. In terms of package, the traditional dual in-line package obviously could not match the size need, the minimal size of recently reported MEMS-based intracranial pressure sensors after packaging is 10 × 10 mm2. In this work, we are the first to introduce a quad flat no-lead package as the package form of piezoresistive intracranial pressure sensors, the whole size of the sensor is minimized to only 3 × 3 mm2. Considering the liquid measurement environment, the sensor is gummed and waterproof performance is tested; the sensitivity of the sensor is 0.9 × 10-2 mV/kPa. Project supported by the National Natural Science Foundation of China (Nos. 61025021, 61434001), and the ‘Thousands Talents’ Program for Pioneer Researchers and Its Innovation Team, China.

  20. Alumina Based 500 C Electronic Packaging Systems and Future Development

    Science.gov (United States)

    Chen, Liang-Yu

    2012-01-01

    NASA space and aeronautical missions for probing the inner solar planets as well as for in situ monitoring and control of next-generation aeronautical engines require high-temperature environment operable sensors and electronics. A 96% aluminum oxide and Au thick-film metallization based packaging system including chip-level packages, printed circuit board, and edge-connector is in development for high temperature SiC electronics. An electronic packaging system based on this material system was successfully tested and demonstrated with SiC electronics at 500 C for over 10,000 hours in laboratory conditions previously. In addition to the tests in laboratory environments, this packaging system has more recently been tested with a SiC junction field effect transistor (JFET) on low earth orbit through the NASA Materials on the International Space Station Experiment 7 (MISSE7). A SiC JFET with a packaging system composed of a 96% alumina chip-level package and an alumina printed circuit board mounted on a data acquisition circuit board was launched as a part of the MISSE7 suite to International Space Station via a Shuttle mission and tested on the orbit for eighteen months. A summary of results of tests in both laboratory and space environments will be presented. The future development of alumina based high temperature packaging using co-fired material systems for improved performance at high temperature and more feasible mass production will also be discussed.

  1. Using the flipped classroom in graduate nursing education.

    Science.gov (United States)

    Critz, Catharine M; Knight, Diane

    2013-01-01

    A flipped classroom is a pedagogical model that involves having students view online lectures, read current evidence-based articles, and complete text readings prior to class. Students then come to class ready to actively engage in collaborative learning through case scenarios, small group discussion, or other meaningful, interactive activities. The flipped classroom model described here was an overwhelming success for both students and faculty.

  2. The Implementation of A Flipped Classroom in Foreign Language Teaching

    Directory of Open Access Journals (Sweden)

    Ahmet BASAL

    2015-10-01

    Full Text Available Alongside the rise of educational technology, many teachers have been taking gradual but innovative steps to redesign their teaching methods. For example, in flipped learning or a flipped classroom, students watch instructional videos outside the classroom and do assignments or engage in activities inside the classroom. Language teachers are one group of educators exploring the flipped classroom. In foreign language classes, such an approach may offer great benefits for both the teachers and students since classroom time can be applied to more interactive tasks. By extending classroom hours in this way, language teachers can focus on successfully addressing all subjects in the curriculum. The aim of this study is (a to gain insights into the perceptions of prospective English language teachers at a state university in Turkey on flipped classrooms and (b to introduce the implementation of a flipped classroom into an English language class. A total of 47 prospective English teachers participated in the study. Qualitative research design was used and data were collected via an open-ended question. Findings of the study indicated that pre-service English teachers had positive perceptions towards the use of the flipped classroom as an integral part of face-to-face courses. It can be concluded that flipped classroom was beneficial in terms of 4 categories based on the content analysis of the responses: learning at one’s own pace, advance student preparation, overcoming the limitations of class time, increasing the participation in the classroom. The study also provides recommendations towards LMS integration into courses in other English language teaching departments and for implementing flipped classrooms in language teaching.

  3. Spin-flip noise in a multiterminal spin valve

    OpenAIRE

    Belzig, Wolfgang; Zareyan, Malek

    2004-01-01

    We study shot noise and cross-correlations in a four terminal spin-valve geometry using a Boltzmann-Langevin approach. The Fano factor (shot noise to current ratio) depends on the magnetic configuration of the leads and the spin-flip processes in the normal metal. In a four-terminal geometry, spin-flip processes are particularly prominent in the cross-correlations between terminals with opposite magnetization.

  4. Comparison of the copper and gold wire bonding processes for LED packaging*

    Institute of Scientific and Technical Information of China (English)

    Chen Zhaohui; Liu Yong; Liu Sheng

    2011-01-01

    Wire bonding is one of the main processes of the LED packaging which provides electrical interconnection between the LED chip and lead frame The gold wire bonding process has been widely used in LED packaging industry currently. However, due to the high cost of gold wire, copper wire bonding is a good substitute for the gold wire bonding which can lead to significant cost saving. In this paper, the copper and gold wire bonding processes on the high power LED chip are compared and analyzed with finite element simulation. This modeling work may provide guidelines for the parameter optimization of coppor wire bonding process on the high power LED packaging.

  5. Photoelasticity analysis of thermal stresses in the plastic ICs. Hikari danseiho ni yoru IC package nai oryoku no keisoku

    Energy Technology Data Exchange (ETDEWEB)

    Hasegawa, T.; Shibuya, Y. (Mitsubishi Electric Corp., Tokyo (Japan))

    1992-10-20

    Recent highly integrated semiconductors have tendencies of being finer patterns and larger silicon chip area. Plastic packages excellent in productivity have been proved to be highly reliable in moisture resistance due to improved sealing resin and have become the main part of IC packages. However, in such devices featuring larger chip area and finer circuit pattern as large capacity memories, the problem of internal stress due to sealing resin contraction has been highlighted as a new problem. In this study, a photoelasticity which is a relatively simple method is employed to evaluate stress within sealing resin, and the review on effects of stress on the interior of sealing resin and chip are reported. Further, the effect of a buffer coat formed on the chip to reduce the stress on a silicon chip, and the effect of package shape on the thermal stress has been examined by means of photoelasticity, and the result is also shown. 10 refs., 18 figs., 2 tabs.

  6. low crosstalk packaging design for Josephson logic circuits

    Energy Technology Data Exchange (ETDEWEB)

    Aoki, K.; Tazoh, Y.; Yoshikiyo, H.

    1985-03-01

    Theoretical and experimental studies are accomplished for inductive crosstalk noise reductions at Josephson chip-to-card connectors. This noise is induced by large AC power and high switching speed signal currents. The crosstalk mechanism was analyzed using a Partial Element Equivalent Circuits Model. Ground inductance causes not only crosstalk noise between connectors but also ground fluctuation noise inside the chip. This ground noise is large enough to cause false logic operations. Test chips and cards with improved connectors were produced for an experimental evaluation. Power crosstalk noise was measured using Josephson sampling circuits fabricated on the chip. The crosstalk noise - signal level ratio was less than 2.5%, when 250 MHz, 50 mA power currents were supplied. Crosstalk noise between neighboring signal connectors was also reduced to negligible level, including the worst case. These results favorably agree with calculations. This low crosstalk packaging design can be applied to high speed Josephson logic systems.

  7. CH Packaging Operations Manual

    Energy Technology Data Exchange (ETDEWEB)

    Washington TRU Solutions LLC

    2005-06-13

    This procedure provides instructions for assembling the CH Packaging Drum payload assembly, Standard Waste Box (SWB) assembly, Abnormal Operations and ICV and OCV Preshipment Leakage Rate Tests on the packaging seals, using a nondestructive Helium (He) Leak Test.

  8. Dual Use Packaging Project

    Data.gov (United States)

    National Aeronautics and Space Administration — NASA seeks down-weighted packaging compatible with microwave preparation and perhaps high hydrostatic pressure processing. New packaging must satisfy NASA's 3-year...

  9. Merganser Download Package

    Data.gov (United States)

    U.S. Environmental Protection Agency — This data download package contains an Esri 10.0 MXD, file geodatabase and copy of this FGDC metadata record. The data in this package are used in support of the...

  10. Comparative Packaging Study

    Science.gov (United States)

    Perchonok, Michele; Antonini, David

    2008-01-01

    This viewgraph presentation describes a comparative packaging study for use on long duration space missions. The topics include: 1) Purpose; 2) Deliverables; 3) Food Sample Selection; 4) Experimental Design Matrix; 5) Permeation Rate Comparison; and 6) Packaging Material Information.

  11. Materials for advanced packaging

    CERN Document Server

    Wong, CP

    2008-01-01

    Significant progress has been made in advanced packaging in recent years. Several new packaging techniques have been developed and new packaging materials have been introduced. This book provides a comprehensive overview of the recent developments in this industry, particularly in the areas of microelectronics, optoelectronics, digital health, and bio-medical applications. The book discusses established techniques, as well as emerging technologies, in order to provide readers with the most up-to-date developments in advanced packaging.

  12. Packaging Printing Today

    OpenAIRE

    Bolanča, Stanislav; Majnarić, Igor; Golubović, Kristijan

    2015-01-01

    Printing packaging covers today about 50% of all the printing products. Among the printing products there are printing on labels, printing on flexible packaging, printing on folding boxes, printing on the boxes of corrugated board, printing on glass packaging, synthetic and metal ones. The mentioned packaging are printed in flexo printing technique, offset printing technique, intaglio halftone process, silk – screen printing, ink ball printing, digital printing and hybrid print...

  13. ATLAS software packaging

    Science.gov (United States)

    Rybkin, Grigory

    2012-12-01

    Software packaging is indispensable part of build and prerequisite for deployment processes. Full ATLAS software stack consists of TDAQ, HLT, and Offline software. These software groups depend on some 80 external software packages. We present tools, package PackDist, developed and used to package all this software except for TDAQ project. PackDist is based on and driven by CMT, ATLAS software configuration and build tool, and consists of shell and Python scripts. The packaging unit used is CMT project. Each CMT project is packaged as several packages—platform dependent (one per platform available), source code excluding header files, other platform independent files, documentation, and debug information packages (the last two being built optionally). Packaging can be done recursively to package all the dependencies. The whole set of packages for one software release, distribution kit, also includes configuration packages and contains some 120 packages for one platform. Also packaged are physics analysis projects (currently 6) used by particular physics groups on top of the full release. The tools provide an installation test for the full distribution kit. Packaging is done in two formats for use with the Pacman and RPM package managers. The tools are functional on the platforms supported by ATLAS—GNU/Linux and Mac OS X. The packaged software is used for software deployment on all ATLAS computing resources from the detector and trigger computing farms, collaboration laboratories computing centres, grid sites, to physicist laptops, and CERN VMFS and covers the use cases of running all applications as well as of software development.

  14. Central heating: package boilers

    Energy Technology Data Exchange (ETDEWEB)

    Farahan, E.

    1977-05-01

    Performance and cost data for electrical and fossil-fired package boilers currently available from manufacturers are provided. Performance characteristics investigated include: unit efficiency, rated capacity, and average expected lifetime of units. Costs are tabulated for equipment and installation of various package boilers. The information supplied in this report will simplify the process of selecting package boilers required for industrial, commercial, and residential applications.

  15. Automating dChip: toward reproducible sharing of microarray data analysis

    Directory of Open Access Journals (Sweden)

    Li Cheng

    2008-05-01

    Full Text Available Abstract Background During the past decade, many software packages have been developed for analysis and visualization of various types of microarrays. We have developed and maintained the widely used dChip as a microarray analysis software package accessible to both biologist and data analysts. However, challenges arise when dChip users want to analyze large number of arrays automatically and share data analysis procedures and parameters. Improvement is also needed when the dChip user support team tries to identify the causes of reported analysis errors or bugs from users. Results We report here implementation and application of the dChip automation module. Through this module, dChip automation files can be created to include menu steps, parameters, and data viewpoints to run automatically. A data-packaging function allows convenient transfer from one user to another of the dChip software, microarray data, and analysis procedures, so that the second user can reproduce the entire analysis session of the first user. An analysis report file can also be generated during an automated run, including analysis logs, user comments, and viewpoint screenshots. Conclusion The dChip automation module is a step toward reproducible research, and it can prompt a more convenient and reproducible mechanism for sharing microarray software, data, and analysis procedures and results. Automation data packages can also be used as publication supplements. Similar automation mechanisms could be valuable to the research community if implemented in other genomics and bioinformatics software packages.

  16. The flipped classroom: now or never?

    Science.gov (United States)

    Hawks, Sharon J

    2014-08-01

    Pedagogical changes and new models of delivering educational content should be considered in the effort to address the recommendations of the 2007 Institute of Medicine report and Benner's recommendations on the radical transformation of nursing. Transition to the nurse anesthesia practice doctorate addresses the importance of these recommendations, but educational models and specific strategies on how to implement changes in educational models and systems are still emerging. The flipped classroom (FC) is generating a considerable amount of buzz in academic circles. The FC is a pedagogical model that employs asynchronous video lectures, reading assignments, practice problems, and other digital, technology-based resources outside the classroom, and interactive, group-based, problem-solving activities in the classroom. This FC represents a unique combination of constructivist ideology and behaviorist principles, which can be used to address the gap between didactic education and clinical practice performance. This article reviews recent evidence supporting use of the FC in health profession education and suggests ways to implement the FC in nurse anesthesia educational programs.

  17. Flipping organic chemistry course: Possibilities and challenges

    Science.gov (United States)

    Cha, J.; Kim, H. B.

    2016-06-01

    The flipped classroom approach was applied to an introductory organic chemistry course. A total of 76 video clips (15 hours of running time) were developed and delivered to 41 sophomores (21 females and 20 males) through Youtube in addition to the university's learning management system. The students were asked to preview the lecture contents before each class by watching a pre-class video. For in-class activities, exercise problems were presented to groups of 3-5 students. An instructor and a teaching assistant guided each group to solve problems cooperatively, monitored the students’ group activity and answered their questions. At the end of every chapter, the students were asked to evaluate their group work and personal preparedness for the class and also to write a short reflective journal. The muddiest point of each chapter, i.e., the topic posing the most difficulty to students’ understanding, was surveyed through Google Forms®. The students liked watching the videos before each class and performing student-centered, in-class group activities but a few limitations were also found and reported.

  18. Flipped classroom or an active lecture?

    Science.gov (United States)

    Pickering, James D; Roberts, David J H

    2017-08-31

    Recent changes in anatomy education have seen the introduction of flipped classrooms as a replacement to the traditional didactic lecture. This approach utilizes the increasing availability of digital technology to create learning resources that can be accessed prior to attending class, with face-to-face sessions then becoming more student-centered via discussion, collaborative learning, and problem-solving activities. Although this approach may appear intuitive, this viewpoint commentary presents a counter opinion and highlights a simple alternative that utilizes evidence-based active learning approaches as part of the traditional lecture. The active lecture takes the traditional lecture, and (1) ensures the lecture content is relevant and has clear objectives, (2) contains lecture material that is designed according to the latest evidence-base, (3) complements it with additional supplementary material, (4) creates space to check prior understanding and knowledge levels, and (5) utilizes suitable technology to facilitate continual engagement and interaction. Clin. Anat., 2017. © 2017 Wiley Periodicals, Inc. © 2017 Wiley Periodicals, Inc.

  19. Mechanical and electrical properties of ultra-thin chips and flexible electronics assemblies during bending

    NARCIS (Netherlands)

    Van Den Ende, D.A.; Van De Wiel, H.J.; Kusters, R.H.L.; Sridhar, A.; Schram, J.F.M.; Cauwe, M.; Van Den Brand, J.

    2014-01-01

    Ultra-thin chips of less than 20 μm become flexible, allowing integration of silicon IC technology with highly flexible electronics such as food packaging sensor systems or healthcare and sport monitoring tags as wearable patches or even directly in clothing textile. The ultra-thin chips in these

  20. Mechanical and electrical properties of ultra-thin chips and flexible electronics assemblies during bending

    NARCIS (Netherlands)

    Van Den Ende, D.A.; Van De Wiel, H.J.; Kusters, R.H.L.; Sridhar, A.; Schram, J.F.M.; Cauwe, M.; Van Den Brand, J.

    2014-01-01

    Ultra-thin chips of less than 20 μm become flexible, allowing integration of silicon IC technology with highly flexible electronics such as food packaging sensor systems or healthcare and sport monitoring tags as wearable patches or even directly in clothing textile. The ultra-thin chips in these pr

  1. Heterogeneously integrated microsystem-on-a-chip

    Science.gov (United States)

    Chanchani, Rajen

    2008-02-26

    A microsystem-on-a-chip comprises a bottom wafer of normal thickness and a series of thinned wafers can be stacked on the bottom wafer, glued and electrically interconnected. The interconnection layer comprises a compliant dielectric material, an interconnect structure, and can include embedded passives. The stacked wafer technology provides a heterogeneously integrated, ultra-miniaturized, higher performing, robust and cost-effective microsystem package. The highly integrated microsystem package, comprising electronics, sensors, optics, and MEMS, can be miniaturized both in volume and footprint to the size of a bottle-cap or less.

  2. Active Packaging Coatings

    Directory of Open Access Journals (Sweden)

    Luis J. Bastarrachea

    2015-11-01

    Full Text Available Active food packaging involves the packaging of foods with materials that provide an enhanced functionality, such as antimicrobial, antioxidant or biocatalytic functions. This can be achieved through the incorporation of active compounds into the matrix of the commonly used packaging materials, or by the application of coatings with the corresponding functionality through surface modification. The latter option offers the advantage of preserving the packaging materials’ bulk properties nearly intact. Herein, different coating technologies like embedding for controlled release, immobilization, layer-by-layer deposition, and photografting are explained and their potential application for active food packaging is explored and discussed.

  3. Coupling structure in LED System-in-Package design: a physical responses-based critical parameter sheet like approach

    NARCIS (Netherlands)

    Borst, E.C.M. de; Gielen, A.W.J.; Etman, L.F.P.

    2012-01-01

    This paper introduces an approach to study the coupling structure between the design parameters and design objectives of a LED system-in-package (SiP) design concept [1]. The LED SiP is an integrated device that combines the LED chip with driver chips and potential other components in a single packa

  4. Coupling structure in LED System-in-Package design: a physical responses-based critical parameter sheet like approach

    NARCIS (Netherlands)

    Borst, E.C.M. de; Gielen, A.W.J.; Etman, L.F.P.

    2012-01-01

    This paper introduces an approach to study the coupling structure between the design parameters and design objectives of a LED system-in-package (SiP) design concept [1]. The LED SiP is an integrated device that combines the LED chip with driver chips and potential other components in a single

  5. Use of single chip microcomputer in hydraulic digital adaptive control system

    Institute of Scientific and Technical Information of China (English)

    2001-01-01

    Presents a one-grade adaptive controller with one reference model which is built according to δ MRACS adaptive control theorv and used to control an actual high-order hydraulic system, and the whole hard ware system used, which includes a AT89C51 single chip microcomputer, 74Ls373 flip-latch, 6116 store, eight-bit ADC0809, and so on, and the satisfactory results obtained in study on hydraulic control system.

  6. Edible packaging materials.

    Science.gov (United States)

    Janjarasskul, Theeranun; Krochta, John M

    2010-01-01

    Research groups and the food and pharmaceutical industries recognize edible packaging as a useful alternative or addition to conventional packaging to reduce waste and to create novel applications for improving product stability, quality, safety, variety, and convenience for consumers. Recent studies have explored the ability of biopolymer-based food packaging materials to carry and control-release active compounds. As diverse edible packaging materials derived from various by-products or waste from food industry are being developed, the dry thermoplastic process is advancing rapidly as a feasible commercial edible packaging manufacturing process. The employment of nanocomposite concepts to edible packaging materials promises to improve barrier and mechanical properties and facilitate effective incorporation of bioactive ingredients and other designed functions. In addition to the need for a more fundamental understanding to enable design to desired specifications, edible packaging has to overcome challenges such as regulatory requirements, consumer acceptance, and scaling-up research concepts to commercial applications.

  7. 电迁移对Ni/Sn3.0Ag0.5Cu/Cu焊点界面反应的影响%EFFECT OF ELECTROMIGRATION ON INTERFACIAL REACTION IN Ni/Sn3.0Ag0.5Cu/Cu FLIP CHIP SOLDER JOINTS

    Institute of Scientific and Technical Information of China (English)

    黄明亮; 陈雷达; 周少明

    2012-01-01

    The effect of electromigration (EM) on the interfacial reaction in Ni/Sn3.0Ag0.5Cu/Cu solder joints was investigated under a current density of 5.0 ×l03 A/cm2 at 150 ℃ All solder joints were aged at 150 ℃ for comparison purpose. It has been found that the (Cu,Ni)6Sn5 intermetallic compounds (IMCs) form at both soIder/Ni and solder/Cu interfaces in the as-reflowed state. During aging at 150 ℃, the thickness of interfacial IMC increases with increasing aging time, and no interfacial IMC transformation occurs even after aging for 800 h. The flowing direction of electrons plays an important role in Cu consumption. When electrons flow from printed circuit board (PCB) to chip, the current crowding effect induces a rapid and localized dissolution of Cu pad on PCB and a formation of microcrack at the Sn3.0Ag0.5Cu/(Cu, Ni)6Sn5 interface. The dissolved Cu atoms are driven towards anode by EM, and a large amount of Cu6Sn5 IMC particles form in solder matrix along the flowing direction of electrons. When electrons flow from chip to PCB, no obvious consumption of Ni underbump metallogy (UBM) has been observed and few Cu6Sn5 IMC particles form in solder matrix near the anode interface. There is no evidence of failure induced by EM in solder joints even after EM for 800 h. To sum up, EM enhances the growth of interfacial (Cu, Ni)6Sn5 at anode side, no matter how the direction of electrons is. The interfacial IMC at anode side is thicker than that at cathode side. The Ni/Sn3.0Ag0.5Cu/Cu solder joint is prone to fail when electrons flowing from Cu to Ni.%研究了温度为150℃,电流密度为5.0×103 A/cm2的条件下电迁移对Ni/Sn3.0Ag0.5Cu/Cu焊点界面反应的影响.回流焊后在Sn3.0Ag0.5Cu/Ni和Sn3.0Ag0.5Cu/Cu的界面上均形成了(Cu,Ni)6Sn5型化合物.时效过程中界面化合物随时效时间增加而增厚,时效800 h后两端的化合物并没有发生转变,仍为(Cu,Ni)6Sn5型.电流方向对Cu基板的消耗起着决定作用.当电子从基板

  8. On flipping first-semester calculus: a case study

    Science.gov (United States)

    Petrillo, Joseph

    2016-05-01

    High failure rates in calculus have plagued students, teachers, and administrators for decades, while science, technology, engineering, and mathematics programmes continue to suffer from low enrollments and high attrition. In an effort to affect this reality, some educators are 'flipping' (or inverting) their classrooms. By flipping, we mean administering course content outside of the classroom and replacing the traditional in-class lectures with discussion, practice, group work, and other elements of active learning. This paper presents the major results from a three-year study of a flipped, first-semester calculus course at a small, comprehensive, American university with a well-known engineering programme. The data we have collected help quantify the positive and substantial effects of our flipped calculus course on failure rates, scores on the common final exam, student opinion of calculus, teacher impact on measurable outcomes, and success in second-semester calculus. While flipping may not be suitable for every teacher, every student, and in every situation, this report provides some evidence that it may be a viable option for those seeking an alternative to the traditional lecture model.

  9. Active Longitudes and Flip-Flops in Binary Stars

    Science.gov (United States)

    Korhonen, Heidi; Järvinen, Silva P.

    2007-08-01

    In many active stars the spots concentrate on two permanent active longitudes which are 180 degrees apart. In some of these stars the dominant part of the spot activity changes the longitude every few years. This so-called flip-flop phenomenon was first reported in the early 1990's in the single, late type giant FK Com. Since then flip-flops have been reported also on binary stars, young solar type stars and the Sun itself. Even though this phenomenon has been detected on many different kinds of active stars, still less than ten stars are known to exhibit this effect. Therefore no statistically significant correlation between the stellar parameters and the flip-flop phenomenon can be carried out. Here we present results from investigation where we have studied the long-term photometry of several magnetically active RS CVn binaries to see whether or not they show permanent active longitudes and the flip-flop phenomenon. We find that it is very common for the active regions to occur on permanent active longitudes, and some of these stars also show clear flip-flop phenomenon.

  10. [Flipped classroom as a strategy to enhance active learning].

    Science.gov (United States)

    Wakabayashi, Noriyuki

    2015-03-01

    This paper reviews the introduction of a flipped class for fourth grade dentistry students, and analyzes the characteristics of the learning method. In fiscal 2013 and 2014, a series of ten three-hour units for removable partial prosthodontics were completed with the flipped class method; a lecture video of approximately 60 minutes was made by the teacher (author) and uploaded to the university's e-learning website one week before each class. Students were instructed to prepare for the class by watching the streaming video on their PC, tablet, or smartphone. In the flipped class, students were not given a lecture, but were asked to solve short questions displayed on screen, to make a short presentation about a part of the video lecture, and to discuss a critical question related to the main subject of the day. An additional team-based learning (TBL) session with individual and group answers was implemented. The average individual scores were considerably higher in the last two years, when the flipped method was implemented, than in the three previous years when conventional lectures were used. The following learning concepts were discussed: the role of the flipped method as an active learning strategy, the efficacy of lecture videos and short questions, students' participation in the class discussion, present-day value of the method, cooperation with TBL, the significance of active learning in relation with the students' learning ability, and the potential increase in the preparation time and workload for students.

  11. Flipped classroom model for learning evidence-based medicine

    Directory of Open Access Journals (Sweden)

    Rucker SY

    2017-08-01

    Full Text Available Sydney Y Rucker,1 Zulfukar Ozdogan,1 Morhaf Al Achkar2 1School of Education, Indiana University, Bloomington, IN, 2Department of Family Medicine, School of Medicine, University of Washington, Seattle, WA, USA Abstract: Journal club (JC, as a pedagogical strategy, has long been used in graduate medical education (GME. As evidence-based medicine (EBM becomes a mainstay in GME, traditional models of JC present a number of insufficiencies and call for novel models of instruction. A flipped classroom model appears to be an ideal strategy to meet the demands to connect evidence to practice while creating engaged, culturally competent, and technologically literate physicians. In this article, we describe a novel model of flipped classroom in JC. We present the flow of learning activities during the online and face-to-face instruction, and then we highlight specific considerations for implementing a flipped classroom model. We show that implementing a flipped classroom model to teach EBM in a residency program not only is possible but also may constitute improved learning opportunity for residents. Follow-up work is needed to evaluate the effectiveness of this model on both learning and clinical practice. Keywords: evidence-based medicine, flipped classroom, residency education

  12. What millennial medical students say about flipped learning

    Directory of Open Access Journals (Sweden)

    Pettit RK

    2017-07-01

    Full Text Available Robin K Pettit, Lise McCoy, Marjorie Kinney School of Osteopathic Medicine in Arizona, A. T. Still University, Mesa, AZ, USA Abstract: Flipped instruction is gaining popularity in medical schools, but there are unanswered questions such as the optimum amount of the curriculum to flip and whether flipped sessions should be mandatory. We were in a unique position to evaluate feedback from first-year medical students who had experienced both flipped and lecture-based courses during their first semester of medical school. A key finding was that the students preferred a variety of different learning formats over an “all or nothing” learning format. Learning format preferences did not necessarily align with perceptions of which format led to better course exam performance. Nearly 70% of respondents wanted to make their own decisions regarding attendance. Candid responses to open-ended survey prompts reflected millennial preferences for choice, flexibility, efficiency, and the ability to control the pace of their learning, providing insight to guide ­curricular improvements. Keywords: flipped classroom, mandatory attendance, medical education, lecture-based, variety

  13. System-in-package technologies for photonics

    Science.gov (United States)

    Tekin, Tolga

    2010-02-01

    System-in-package technology is announced as one of the key technologies, which enables the continued increase in functional density and decrease in cost per function required to maintain the progress of electronics by utilizing 3D through innovation in packaging and interconnect technology. A key bottleneck to the realization of high-performance microelectronic systems is the lack of low latency, high-bandwidth, and high density off-chip interconnects. Photonics could overcome these challenges and leverage low-latency and high bandwidth communication within next generation architectures. In this paper state-of-the-art approaches will be discussed and the requirements in 3D integration perspective of converging platforms will be addressed.

  14. An Experiential Learning Perspective on Students’ Satisfaction Model in a Flipped Classroom Context

    National Research Council Canada - National Science Library

    Xuesong Zhai; Jibao Gu; Hefu Liu; Jyh-Chong Liang; Chin-Chung Tsai

    2017-01-01

    ...’ perceptions of flipped settings. In order to fill this gap, in this study, a students’ satisfaction model for the flipped classroom was constructed based on the experiential learning theory...

  15. Using 3DClass To Flip Biochemistry Classroom

    Directory of Open Access Journals (Sweden)

    T. Silva

    2014-08-01

    Full Text Available The flipped classroom inverts traditional teaching methods, in order to have studentsprepared for topics and techniques covered in the following meeting. This approach wasadopted in a biochemistry course taught to biology freshmen students at the University ofCampinas, using a Virtual Learning Environment called 3DClass. Before each classroomsession, a quiz was delivered covering the following topic and students were allowed totake quizzes as many times as they wanted. This approach was utilized in order to betterprepare students in classes and to perform lab experiments. Every student attempt wasrecorded in a database. Before each classroom session, the instructors were provided witha summary of the class answers, highlighting questions where students had more difficultyand the ones that scored higher. This kind of information was helpful to design activities tocover the topics where students had more difficulties. Based on the 3DClass records thestudents behaviors were mapped, such as students taking the quizzes seriously, studentsguessing, students answering a quiz until scoring 100%, students that continue answeringafter scoring 100% in order to increase their grades, students that never score 100%.However, the most relevant information 3DClass brought us was the possibility to identifystudent’s confidence in their answers, which could be observed by the analysis of theirattempts for each question. If they had made different choices each try, it would haveindicated a low confidence level, while always providing the same answer indicated ahigher confidence level, even whilst picking incorrect answers. This experiment haverevealed that students coming to the classroom better prepared reflected positively on thedeveloped activities, but the number of students taking the quizzes seriously were not asgreat as we had expected, indicating that more actions should be taken to improvestudents engagement with these activities.

  16. Cleanup Verification Package for the 118-F-1 Burial Ground

    Energy Technology Data Exchange (ETDEWEB)

    E. J. Farris and H. M. Sulloway

    2008-01-10

    This cleanup verification package documents completion of remedial action for the 118-F-1 Burial Ground on the Hanford Site. This burial ground is a combination of two locations formerly called Minor Construction Burial Ground No. 2 and Solid Waste Burial Ground No. 2. This waste site received radioactive equipment and other miscellaneous waste from 105-F Reactor operations, including dummy elements and irradiated process tubing; gun barrel tips, steel sleeves, and metal chips removed from the reactor; filter boxes containing reactor graphite chips; and miscellaneous construction solid waste.

  17. Flipped Instruction in a High School Science Classroom

    Science.gov (United States)

    Leo, Jonathan; Puzio, Kelly

    2016-10-01

    This paper reports on a quasi-experimental study examining the effectiveness of flipped instruction in a 9th grade biology classroom. This study included four sections of freshmen-level biology taught by the first author at a private secondary school in the Pacific Northwest. Using a block randomized design, two sections were flipped and two remained traditional. The quiz and posttest data were adjusted for pretest differences using ANCOVA. The results suggest that flipped instruction had a positive effect student achievement, with effect sizes ranging from +0.16 to +0.44. In addition, some students reported that they preferred watching video lectures outside of class and appreciated more active approaches to learning.

  18. Out of Classroom Instruction in the Flipped Classroom

    DEFF Research Database (Denmark)

    Triantafyllou, Evangelia; Timcenko, Olga

    2015-01-01

    This article presents experiences and student perceptions on the introduction of the flipped classroom model in two consecutive semesters at Media Technology department of Aalborg University, Copenhagen, Denmark. We introduced the flipped instruction model to a statistics course and a mathematics...... workshop. We collected data by two online survey studies, which show support for student perceptions that out-of-classroom instruction with online resources enhances learning, by providing visual and in depth explanations, and can engage the learner. However, students stated that they miss just......-in-time explanations when learning with online resources and they questioned the quality and validity of some of them. Based on these findings and our own experience, we discuss requirements for resources and activities in flipped classrooms in order for the student to engage and learn. Finally, we present a framework...

  19. Graphene Layer Growth Chemistry: Five-Six-Ring Flip Reaction

    Energy Technology Data Exchange (ETDEWEB)

    Whitesides, R.; Domin, D.; Salomon-Ferrer, R.; Lester Jr., W.A.; Frenklach, M.

    2007-12-01

    Reaction pathways are presented for hydrogen-mediated isomerization of a five and six member carbon ring complex on the zigzag edge of a graphene layer. A new reaction sequence that reverses orientation of the ring complex, or 'flips' it, was identified. Competition between the flip reaction and 'ring separation' was examined. Ring separation is the reverse of the five and six member ring complex formation reaction, previously reported as 'ring collision'. The elementary steps of the pathways were analyzed using density-functional theory (DFT). Rate coefficients were obtained by solution of the energy master equation and classical transition state theory utilizing the DFT energies, frequencies, and geometries. The results indicate that the flip reaction pathway dominates the separation reaction and should be competitive with other pathways important to the graphene zigzag edge growth in high temperature environments.

  20. Spin flip of multiqubit states in discrete phase space

    Science.gov (United States)

    Srinivasan, K.; Raghavan, G.

    2017-02-01

    Time reversal and spin flip are discrete symmetry operations of substantial importance to quantum information and quantum computation. Spin flip arises in the context of separability, quantification of entanglement and the construction of universal NOT gates. The present work investigates the relationship between the quantum state of a multiqubit system represented by the discrete Wigner function (DWFs) and its spin-flipped counterpart. The two are shown to be related through a Hadamard matrix that is independent of the choice of the quantum net used for the tomographic reconstruction of the DWF. These results are of interest to cases involving the direct tomographic reconstruction of the DWF from experimental data, and in the analysis of entanglement related properties purely in terms of the DWF.

  1. Fully simulatable quantum-secure coin-flipping and applications

    DEFF Research Database (Denmark)

    Lunemann, Carolin; Nielsen, Jesper Buus

    2011-01-01

    We propose a coin-flip protocol which yields a string of strong, random coins and is fully simulatable against poly-sized quantum adversaries on both sides. It can be implemented with quantum-computational security without any set-up assumptions, since our construction only assumes mixed commitment...... schemes which we show how to construct in the given setting. We then show that the interactive generation of random coins at the beginning or during outer protocols allows for quantum-secure realizations of classical schemes, again without any set-up assumptions. As example applications we discuss quantum...... zero-knowledge proofs of knowledge and quantum-secure two-party function evaluation. Both applications assume only fully simulatable coin-flipping and mixed commitments. Since our framework allows to construct fully simulatable coin-flipping from mixed commitments, this in particular shows that mixed...

  2. Two-Bit Bit Flipping Decoding of LDPC Codes

    CERN Document Server

    Nguyen, Dung Viet; Marcellin, Michael W

    2011-01-01

    In this paper, we propose a new class of bit flipping algorithms for low-density parity-check (LDPC) codes over the binary symmetric channel (BSC). Compared to the regular (parallel or serial) bit flipping algorithms, the proposed algorithms employ one additional bit at a variable node to represent its "strength." The introduction of this additional bit increases the guaranteed error correction capability by a factor of at least 2. An additional bit can also be employed at a check node to capture information which is beneficial to decoding. A framework for failure analysis of the proposed algorithms is described. These algorithms outperform the Gallager A/B algorithm and the min-sum algorithm at much lower complexity. Concatenation of two-bit bit flipping algorithms show a potential to approach the performance of belief propagation (BP) decoding in the error floor region, also at lower complexity.

  3. Vacuum packaging technology for mass production of uncooled IRFPAs

    Science.gov (United States)

    Ito, Takuya; Tokuda, Takayuki; Kimata, Masafumi; Abe, Hideyuki; Tokashiki, Naotaka

    2009-05-01

    We developed vacuum packaging equipment and low-cost vacuum packaging technology for the mass production of uncooled IRFPAs. The equipment consists of two chambers with identical construction. Two-chamber architecture provides flexibility in the vacuum packaging process, so we can bake the components and achieve getter activation by heating, stem/cap soldering, and cap/window soldering in a series under high-vacuum conditions. Heaters and component-holding jigs are made of graphite to assure rapid and uniform heating to 500°C. The batch size is 27 if we choose a 15-mm diameter TO8 package and can be increased by enlarging the graphite heater area. We also developed a micro-vacuum gauge to evaluate the vacuum level in encapsulated packages. The operation principle of this vacuum gauge is based on thermal conduction by air molecules. It can be integrated in IRFPA chips since the fabrication process is compatible with that for IRFPAs. We encapsulated the vacuum gauges in TO8 packages with our vacuum packaging equipment, and confirmed that the pressure in fabricated packages is sufficiently low for high performance IRFPA operation (<< 1 Pa) with the micro-vacuum gauges.

  4. The flipped classroom for professional development: part I. Benefits and strategies.

    Science.gov (United States)

    McDonald, Katie; Smith, Charlene M

    2013-10-01

    Individualizing the educational encounter is supported by flipping the classroom experience. This column offers an overview and describes the benefits of flipping the classroom. Part II will explore the practicalities and pedagogy of lecture capture using podcasts and videos, a technology strategy used in flipping the classroom.

  5. [Evaluation of flipped classroom teaching model in undergraduates education of oral and maxillofacial surgery].

    Science.gov (United States)

    Cai, Ming; Cao, Xia; Fang, Xiao; Wang, Xu-dong; Zhang, Li-li; Zheng, Jia-wei; Shen, Guo-fang

    2015-12-01

    Flipped classroom is a new teaching model which is different from the traditional teaching method. The history and characteristics of flipped classroom teaching model were introduced in this paper. A discussion on how to establish flipped classroom teaching protocol in oral and maxillofacial surgery education was carried out. Curriculum transformation, construction of education model and possible challenges were analyzed and discussed.

  6. Scaffolded Semi-Flipped General Chemistry Designed to Support Rural Students' Learning

    Science.gov (United States)

    Lenczewski, Mary S.

    2016-01-01

    Students who lack academic maturity can sometimes feel overwhelmed in a fully flipped classroom. Here an alternative, the Semi-Flipped method, is discussed. Rural students, who face unique challenges in transitioning from high school learning to college-level learning, can particularly profit from the use of the Semi-Flipped method in the General…

  7. K-12 Teacher Perceptions Regarding the Flipped Classroom Model for Teaching and Learning

    Science.gov (United States)

    Gough, Evan; DeJong, David; Grundmeyer, Trent; Baron, Mark

    2017-01-01

    A great deal of evidence can be cited from higher education literature on the effectiveness of the flipped classroom; however, very little research was discovered on the flipped classroom at the K-12 level. This study examined K-12 teachers' perceptions regarding the flipped classroom and differences in teachers' perceptions based on grade level…

  8. Present Research on the Flipped Classroom and Potential Tools for the EFL Classroom

    Science.gov (United States)

    Mehring, Jeff

    2016-01-01

    The flipped classroom can support the implementation of a communicative, student-centered learning environment in the English as a foreign language classroom. Unfortunately, there is little research which supports the incorporation of flipped learning in the English as a foreign language classroom. Numerous studies have focused on flipped learning…

  9. Student learning and perceptions in a flipped linear algebra course

    Science.gov (United States)

    Love, Betty; Hodge, Angie; Grandgenett, Neal; Swift, Andrew W.

    2014-04-01

    The traditional lecture style of teaching has long been the norm in college science, technology, engineering, and mathematics (STEM) courses, but an innovative teaching model, facilitated by recent advances in technology, is gaining popularity across college campuses. This new model inverts or 'flips' the usual classroom paradigm, in that students learn initial course concepts outside of the classroom, while class time is reserved for more active problem-based learning and practice activities. While the flipped classroom model shows promise for improving STEM learning and increasing student interest in STEM fields, discussions to date of the model and its impact are more anecdotal than data driven - very little research has been undertaken to rigorously assess the potential effects on student learning that can result from the flipped classroom environment. This study involved 55 students in 2 sections of an applied linear algebra course, using the traditional lecture format in one section and the flipped classroom model in another. In the latter, students were expected to prepare for the class in some way, such as watching screencasts prepared by the instructor, or reading the textbook or the instructor's notes. Student content understanding and course perceptions were examined. Content understanding was measured by the performance on course exams, and students in the flipped classroom environment had a more significant increase between the sequential exams compared to the students in the traditional lecture section, while performing similarly in the final exam. Course perceptions were represented by an end-of-semester survey that indicated that the flipped classroom students were very positive about their experience in the course, and particularly appreciated the student collaboration and instructional video components.

  10. Packaging for Sustainability

    CERN Document Server

    Lewis, Helen; Fitzpatrick, Leanne

    2012-01-01

    The packaging industry is under pressure from regulators, customers and other stakeholders to improve packaging’s sustainability by reducing its environmental and societal impacts. This is a considerable challenge because of the complex interactions between products and their packaging, and the many roles that packaging plays in the supply chain. Packaging for Sustainability is a concise and readable handbook for practitioners who are trying to implement sustainability strategies for packaging. Industry case studies are used throughout the book to illustrate possible applications and scenarios. Packaging for Sustainability draws on the expertise of researchers and industry practitioners to provide information on business benefits, environmental issues and priorities, environmental evaluation tools, design for environment, marketing strategies, and challenges for the future.

  11. MEMS-Based Quartz Oscillators and Filters for On-Chip Integration

    Science.gov (United States)

    2005-01-01

    frequency RF electronics, and vacuum packaging the resulting chip at wafer level, are not possible with present techniques. Polysilicon surface...and is compatible with MEMS-based wafer-scale vacuum packaging . Fundamental mode operation above 2 GHz has been demonstrated with Q’s of 7,200 in air

  12. All-optical flip-flop and control methods thereof

    Science.gov (United States)

    Maywar, Drew; Agrawal, Govind P.

    2010-03-23

    Embodiments of the invention pertain to remote optical control of holding beam-type, optical flip-flop devices, as well as to the devices themselves. All-optical SET and RE-SET control signals operate on a cw holding beam in a remote manner to vary the power of the holding beam between threshold switching values to enable flip-flop operation. Cross-gain modulation and cross-polarization modulation processes can be used to change the power of the holding beam.

  13. Flipped version of the supersymmetric strongly coupled preon model

    Science.gov (United States)

    Fajfer, S.; Mileković, M.; Tadić, D.

    1989-12-01

    In the supersymmetric SU(5) [SUSY SU(5)] composite model (which was described in an earlier paper) the fermion mass terms can be easily constructed. The SUSY SU(5)⊗U(1), i.e., flipped, composite model possesses a completely analogous composite-particle spectrum. However, in that model one cannot construct a renormalizable superpotential which would generate fermion mass terms. This contrasts with the standard noncomposite grand unified theories (GUT's) in which both the Georgi-Glashow electrical charge embedding and its flipped counterpart lead to the renormalizable theories.

  14. A non-volatile flip-flop based on diode-selected PCM for ultra-low power systems

    Science.gov (United States)

    Ye, Yong; Du, Yuan; Gao, Dan; Kang, Yong; Song, Zhitang; Chen, Bomy

    2016-10-01

    As the process technology is continuously shrinking, low power consumption is a major issue in VLSI Systems-on-Chip (SoCs), especially for standby-power-critical applications. Recently, the emerging CMOS-compatible non-volatile memories (NVMs), such as Phase Change Memory (PCM), have been used as on-chip storage elements, which can obtain non-volatile processing, nearly-zero standby power and instant-on capability. PCM has been considered as the best candidate for the next generation of NVMs for its low cost, high density and high resistance transformation ratio. In this paper, for the first time, we present a diode-selected PCM based non-volatile flip-flop (NVFF) which is optimized for better power consumption and process variation tolerance. With dual trench isolation process, the diode-selected PCM realizes ultra small area, which is very suitable for multi-context configuration and large scale flip-flops matrix. Since the MOS-selected PCM is hard to shrink further due to large amount of PCM write current, the proposed NVFF achieves higher power efficiency without loss of current driving capability. Using the 40nm manufacturing process, the area of the cell (1D1R) is as small as 0.016 μm2. Simulation results show that the energy consumption during the recall operation is 62 fJ with 1.1 standard supply voltage, which is reduced by 54.9% compared to the previous 2T2R based NVFF. When the supply voltage reduces to 0.7 V, the recall energy is as low as 17 fJ. With the great advantages in cell size and energy, the proposed diode-selected NVFF is very applicable and cost-effective for ULP systems.

  15. Packaging and testing of multi-wavelength DFB laser array using REC technology

    Science.gov (United States)

    Ni, Yi; Kong, Xuan; Gu, Xiaofeng; Chen, Xiangfei; Zheng, Guanghui; Luan, Jia

    2014-02-01

    Packaging of distributed feedback (DFB) laser array based on reconstruction-equivalent-chirp (REC) technology is a bridge from chip to system, and influences the practical process of REC chip. In this paper, DFB laser arrays of 4-channel @1310 nm and 8-channel @1550 nm are packaged. Our experimental results show that both these laser arrays have uniform wavelength spacing and larger than 35 dB average Side Mode Suppression Ratio (SMSR). When I=35 mA, we obtain the total output power of 1 mW for 4-channel @1310 nm, and 227 μw for 8-channel @1550 nm respectively. The high frequency characteristics of the packaged chips are also obtained, and the requirements for 4×10 G or even 8×10 G systems can be reached. Our results demonstrate the practical and low cost performance of REC technology and indicate its potential in the future fiber-to-the-home (FTTH) application.

  16. Realtime 3D stress measurement in curing epoxy packaging

    DEFF Research Database (Denmark)

    Richter, Jacob; Hyldgård, A.; Birkelund, Karen;

    2007-01-01

    This paper presents a novel method to characterize stress in microsystem packaging. A circular p-type piezoresistor is implemented on a (001) silicon chip. We use the circular stress sensor to determine the packaging induced stress in a polystyrene tube filled with epoxy. The epoxy curing process...... is monitored by stress measurements. From the stress measurements we conclude that the epoxy cures in 8 hours at room temperature. We find the difference in in-plane normal stresses to be sigmaxx-sigmayy=6.7 MPa and (sigmaxx+sigmayy-0.4sigmazz)=232 MPa....

  17. LED packaging for lighting applications design, manufacturing, and testing

    CERN Document Server

    Liu, Sheng

    2011-01-01

    Since the first light-emitting diode (LED) was invented by Holonyak and Bevacqua in 1962, LEDs have made remarkable progress in the past few decades with the rapid development of epitaxy growth, chip design and manufacture, packaging structure, processes, and packaging materials. LEDs have superior characteristics such as high efficiency, small size, long life, low power consumption, and high reliability. The market for white LED is growing rapidly in various applications. It has been widely accepted that white LEDs will be the fourth illumination source to substitute the incandescent, fluores

  18. Grooming. Learning Activity Package.

    Science.gov (United States)

    Stark, Pamela

    This learning activity package on grooming for health workers is one of a series of 12 titles developed for use in health occupations education programs. Materials in the package include objectives, a list of materials needed, information sheets, reviews (self evaluations) of portions of the content, and answers to reviews. These topics are…

  19. Packaging issues: avoiding delamination.

    Science.gov (United States)

    Hall, R

    2005-10-01

    Manufacturers can minimise delamination occurrence by applying the appropriate packaging design and process features. The end user can minimise the impact of fibre tear and reduce subsequent delamination by careful package opening. The occasional inconvenient delamination is a small price to pay for the high level of sterility assurance that comes with the use of Tyvek.

  20. WASTE PACKAGE TRANSPORTER DESIGN

    Energy Technology Data Exchange (ETDEWEB)

    D.C. Weddle; R. Novotny; J. Cron

    1998-09-23

    The purpose of this Design Analysis is to develop preliminary design of the waste package transporter used for waste package (WP) transport and related functions in the subsurface repository. This analysis refines the conceptual design that was started in Phase I of the Viability Assessment. This analysis supports the development of a reliable emplacement concept and a retrieval concept for license application design. The scope of this analysis includes the following activities: (1) Assess features of the transporter design and evaluate alternative design solutions for mechanical components. (2) Develop mechanical equipment details for the transporter. (3) Prepare a preliminary structural evaluation for the transporter. (4) Identify and recommend the equipment design for waste package transport and related functions. (5) Investigate transport equipment interface tolerances. This analysis supports the development of the waste package transporter for the transport, emplacement, and retrieval of packaged radioactive waste forms in the subsurface repository. Once the waste containers are closed and accepted, the packaged radioactive waste forms are termed waste packages (WP). This terminology was finalized as this analysis neared completion; therefore, the term disposal container is used in several references (i.e., the System Description Document (SDD)) (Ref. 5.6). In this analysis and the applicable reference documents, the term ''disposal container'' is synonymous with ''waste package''.

  1. CYPROS - Cybernetic Program Packages

    Directory of Open Access Journals (Sweden)

    Arne Tyssø

    1980-10-01

    Full Text Available CYPROS is an interactive program system consisting of a number of special purpose packages for simulation, identification, parameter estimation and control system design. The programming language is standard FORTRAN IV and the system is implemented on a medium size computer system (Nord-10. The system is interactive and program control is obtained by the use of numeric terminals. Output is rapidly examined by extensive use of video colour graphics. The subroutines included in the packages are designed and documented according to standardization rules given by the SCL (Scandinavian Control Library organization. This simplifies the exchange of subroutines throughout the SCL system. Also, this makes the packages attractive for implementation by industrial users. In the simulation package, different integration methods are available and it can be easily used for off-line, as well as real time, simulation problems. The identification package consists of programs for single-input/single-output and multivariablc problems. Both transfer function models and state space models can be handled. Optimal test signals can be designed. The control package consists of programs based on multivariable time domain and frequency domain methods for analysis and design. In addition, there is a package for matrix and time series manipulation. CYPROS has been applied successfully to industrial problems of various kinds, and parts of the system have already been implemented on different computers in industry. This paper will, in some detail, describe the use and the contents of the packages and some examples of application will be discussed.

  2. User friendly packaging

    DEFF Research Database (Denmark)

    Geert Jensen, Birgitte

    2010-01-01

    Most consumers have experienced occasional problems with opening packaging. Tomato sauce from the tinned mackerel splattered all over the kitchen counter, the unrelenting pickle jar lid, and the package of sliced ham that cannot be opened without a knife or a pair of scissors. The research project...

  3. Statistical Power Supply Dynamic Noise Prediction in Hierarchical Power Grid and Package Networks

    OpenAIRE

    Piccinini, Gianluca; Graziano, Mariagrazia

    2008-01-01

    One of the most crucial high performance systems-on-chip design challenge is to front their power supply noise sufferance due to high frequencies, huge number of functional blocks and technology scaling down. Marking a difference from traditional post physical-design static voltage drop analysis, /a priori dynamic voltage drop/evaluation is the focus of this work. It takes into account transient currents and on-chip and package /RLC/ parasitics while exploring the power grid design solution s...

  4. Packaging Technologies for 500 C SiC Electronics and Sensors: Challenges in Material Science and Technology

    Science.gov (United States)

    Chen, Liang-Yu; Neudeck, Philip G.; Behelm, Glenn M.; Spry, David J.; Meredith, Roger D.; Hunter, Gary W.

    2015-01-01

    This paper presents ceramic substrates and thick-film metallization based packaging technologies in development for 500C silicon carbide (SiC) electronics and sensors. Prototype high temperature ceramic chip-level packages and printed circuit boards (PCBs) based on ceramic substrates of aluminum oxide (Al2O3) and aluminum nitride (AlN) have been designed and fabricated. These ceramic substrate-based chip-level packages with gold (Au) thick-film metallization have been electrically characterized at temperatures up to 550C. The 96 alumina packaging system composed of chip-level packages and PCBs has been successfully tested with high temperature SiC discrete transistor devices at 500C for over 10,000 hours. In addition to tests in a laboratory environment, a SiC junction field-effect-transistor (JFET) with a packaging system composed of a 96 alumina chip-level package and an alumina printed circuit board was tested on low earth orbit for eighteen months via a NASA International Space Station experiment. In addition to packaging systems for electronics, a spark-plug type sensor package based on this high temperature interconnection system for high temperature SiC capacitive pressure sensors was also developed and tested. In order to further significantly improve the performance of packaging system for higher packaging density, higher operation frequency, power rating, and even higher temperatures, some fundamental material challenges must be addressed. This presentation will discuss previous development and some of the challenges in material science (technology) to improve high temperature dielectrics for packaging applications.

  5. Flipping the Science Classroom: Exploring Merits, Issues and Pedagogy

    Science.gov (United States)

    Ng, Wan

    2014-01-01

    Educators are continually being challenged to think about how best to integrate digital technologies meaningfully and effectively in their classrooms. A current trend in educational technology which has the potential to enable this in a pragmatic manner is the flipped classroom concept. This paper aims to explore the idea in Science teaching and…

  6. Case Study: Student-Produced Videos for the Flipped Classroom

    Science.gov (United States)

    Prud'homme-Genereux, Annie

    2016-01-01

    This column provides original articles on innovations in case study teaching, assessment of the method, as well as case studies with teaching notes. This month's issue describes a way of building a library of student-produced videos to use in the flipped classroom.

  7. Adult Students' Experiences of a Flipped Mathematics Classroom

    Science.gov (United States)

    Larsen, Judy

    2015-01-01

    The flipped classroom is a flexible blended learning model that is growing in popularity due to the emergent accessibility to online content delivery technology. By delivering content outside of class time asynchronously, teachers are able to dedicate their face to face class time for student-centred teaching approaches. The flexibility in…

  8. Implementation and Critical Assessment of the Flipped Classroom Experience

    Science.gov (United States)

    Scheg, Abigail G., Ed.

    2015-01-01

    In the past decade, traditional classroom teaching models have been transformed in order to better promote active learning and learner engagement. "Implementation and Critical Assessment of the Flipped Classroom Experience" seeks to capture the momentum of non-traditional teaching methods and provide a necessary resource for individuals…

  9. Successful EFL Teaching Using Mobile Technologies in a Flipped Classroom

    Science.gov (United States)

    Obari, Hiroyuki; Lambacher, Stephen

    2015-01-01

    Two case studies evaluating the effectiveness of a flipped classroom compared to a traditional classroom were performed. The studies were conducted from April 2014 to January 2015 at a private university in Tokyo, targeting 60 first-year and 25 third-year undergraduates, respectively. In the first study, an assessment of pre- and post-treatment…

  10. On flipping the classroom in large first year calculus courses

    Science.gov (United States)

    Jungić, Veselin; Kaur, Harpreet; Mulholland, Jamie; Xin, Cindy

    2015-05-01

    Over the course of two years, 2012--2014, we have implemented a 'flipping' the classroom approach in three of our large enrolment first year calculus courses: differential and integral calculus for scientists and engineers. In this article we describe the details of our particular approach and share with the reader some experiences of both instructors and students.

  11. Microlectures in a Flipped Classroom: Application, Creation and Resources

    Science.gov (United States)

    Sweet, Dawn

    2014-01-01

    Using microlectures in a flipped classroom is a growing trend. In this media review, the benefits of microlectures for such classrooms are discussed, including how they can be used to help students become more responsible for their learning, as well as how they can be used by teachers to provide differentiated instruction. A list of resources for…

  12. Reflections on a Flipped Classroom in First Year Higher Education

    Science.gov (United States)

    McCarthy, Josh

    2016-01-01

    This paper explores the efficacy of a flipped classroom model for teaching first year students three-dimensional (3D) animation, and analyses the advantages and disadvantages when compared to traditional teaching mechanisms. In 2015, within the course "Introduction to CGI" at the University of South Australia, two different tutorial…

  13. Using Digital Learning Platforms to Extend the Flipped Classroom

    Science.gov (United States)

    Balzotti, Jonathan M.; McCool, Lynn B.

    2016-01-01

    Although digital environments already play a vital role in the flipped classroom model, this research project shows that in university writing classrooms, innovative content design and delivery systems can extend the walls of the classroom to areas beyond, in which students transfer and connect course content with the professional world. In this…

  14. Inquiry-Based Learning and the Flipped Classroom Model

    Science.gov (United States)

    Love, Betty; Hodge, Angie; Corritore, Cynthia; Ernst, Dana C.

    2015-01-01

    The flipped classroom model of teaching can be an ideal venue for turning a traditional classroom into an engaging, inquiry-based learning (IBL) environment. In this paper, we discuss how two instructors at different universities made their classrooms come to life by moving the acquisition of basic course concepts outside the classroom and using…

  15. Flipping & Clicking Your Way to Higher-Order Learning

    Science.gov (United States)

    Garver, Michael S.; Roberts, Brian A.

    2013-01-01

    This innovative system of teaching and learning includes the implementation of two effective learning technologies: podcasting ("flipping") and classroom response systems ("clicking"). Students watch lectures in podcast format before coming to class, which allows the "entire" class period to be devoted to active…

  16. Using Flip Camcorders for Active Classroom Metacognitive Reflection

    Science.gov (United States)

    Hargis, Jace; Marotta, Sebastian M.

    2011-01-01

    A Center for Teaching and Learning provided Flip camcorders to a group of 10 new faculty members, who were asked to use this teaching tool in their classroom instruction. The classes included mathematics, political science, computer engineering, psychology, business, music and dance. The qualitative results indicate that all faculty members and…

  17. University and Flipped Learning TIC & DIL Project: Framework and Design

    Science.gov (United States)

    Pinnelli, Stefania; Fiorucci, Andrea

    2015-01-01

    The flipped classroom approach (FC) is for the educational world a chance of recovery and improvement of pedagogical student-centered model and collaborative teaching methods aimed at optimizing the time resource and to promote personalization and self-learning in a perspective of autonomy. The paper moving from a pedagogical reflection on…

  18. Fermion helicity flip in higher-derivative electromagnetism

    Energy Technology Data Exchange (ETDEWEB)

    Accioly, A.J. [Instituto de Fisica Teorica (IFT), Sao Paulo, SP (Brazil); Mukai, H. [Universidade Estadual de Maringa, PR (Brazil). Dept. de Fisica

    1996-10-01

    It is shown that massive fermions have their helicity flipped on account of their interaction with an electromagnetic field described by Podolsky`s generalized electrodynamics. Massless fermions, in turn, seem to be unaffected by the electromagnetic field as far as their helicity is concerned. (author).

  19. On Flipping the Classroom in Large First Year Calculus Courses

    Science.gov (United States)

    Jungic, Veselin; Kaur, Harpreet; Mulholland, Jamie; Xin, Cindy

    2015-01-01

    Over the course of two years, 2012-2014, we have implemented a "flipping" the classroom approach in three of our large enrolment first year calculus courses: differential and integral calculus for scientists and engineers. In this article we describe the details of our particular approach and share with the reader some experiences of…

  20. The Effectiveness of a Technology-Enhanced Flipped Science Classroom

    Science.gov (United States)

    Sezer, Baris

    2017-01-01

    This study examined the effect on the learning and motivation of students of a flipped classroom environment enriched with technology. A mixed research design using a pretest or posttest experimental model, combined with qualitative data, was conducted in a public middle school in Turkey for 2 weeks (three class hours) within a science course.…

  1. On Flipping the Classroom in Large First Year Calculus Courses

    Science.gov (United States)

    Jungic, Veselin; Kaur, Harpreet; Mulholland, Jamie; Xin, Cindy

    2015-01-01

    Over the course of two years, 2012-2014, we have implemented a "flipping" the classroom approach in three of our large enrolment first year calculus courses: differential and integral calculus for scientists and engineers. In this article we describe the details of our particular approach and share with the reader some experiences of…

  2. Can Flipping the Classroom Work? Evidence from Undergraduate Chemistry

    Science.gov (United States)

    Casasola, Timothy; Nguyen, Tutrang; Warschauer, Mark; Schenke, Katerina

    2017-01-01

    Our study describes student outcomes from an undergraduate chemistry course that implemented a flipped format: a pedagogical model that consists of students watching recorded video lectures outside of the classroom and engaging in problem solving activities during class. We investigated whether (1) interest, study skills, and attendance as…

  3. Preparing Students for Flipped or Team-Based Learning Methods

    Science.gov (United States)

    Balan, Peter; Clark, Michele; Restall, Gregory

    2015-01-01

    Purpose: Teaching methods such as Flipped Learning and Team-Based Learning require students to pre-learn course materials before a teaching session, because classroom exercises rely on students using self-gained knowledge. This is the reverse to "traditional" teaching when course materials are presented during a lecture, and students are…

  4. Periodicals Price Survey 2002: Doing the Digital Flip.

    Science.gov (United States)

    Van Orsdel, Lee; Born, Kathleen

    2002-01-01

    Presents the annual periodicals price study. Highlights include average prices; cost histories; cost projections for future budgeting; electronic journal issues; flip pricing, defined as online access at the core of pricing negotiations; various pricing models; purchasing print at deeply discounted prices; and current trends in pricing and in the…

  5. The Flipped Classroom Model: When Technology Enhances Professional Skills

    Science.gov (United States)

    Baytiyeh, Hoda

    2017-01-01

    Purpose: The purpose of this paper is to investigate the effectiveness of the flipped classroom model in teaching and learning as well as the skills that can be acquired by students after being exposed to this learning style. Design/methodology/approach: This paper uses a qualitative case study design. In total, 20 students, from various majors,…

  6. Student Learning and Perceptions in a Flipped Linear Algebra Course

    Science.gov (United States)

    Love, Betty; Hodge, Angie; Grandgenett, Neal; Swift, Andrew W.

    2014-01-01

    The traditional lecture style of teaching has long been the norm in college science, technology, engineering, and mathematics (STEM) courses, but an innovative teaching model, facilitated by recent advances in technology, is gaining popularity across college campuses. This new model inverts or "flips" the usual classroom paradigm, in…

  7. Using Flip Camcorders for Active Classroom Metacognitive Reflection

    Science.gov (United States)

    Hargis, Jace; Marotta, Sebastian M.

    2011-01-01

    A Center for Teaching and Learning provided Flip camcorders to a group of 10 new faculty members, who were asked to use this teaching tool in their classroom instruction. The classes included mathematics, political science, computer engineering, psychology, business, music and dance. The qualitative results indicate that all faculty members and…

  8. The Flipped Classroom Model: When Technology Enhances Professional Skills

    Science.gov (United States)

    Baytiyeh, Hoda

    2017-01-01

    Purpose: The purpose of this paper is to investigate the effectiveness of the flipped classroom model in teaching and learning as well as the skills that can be acquired by students after being exposed to this learning style. Design/methodology/approach: This paper uses a qualitative case study design. In total, 20 students, from various majors,…

  9. Homoclinic Bifurcation of Orbit Flip with Resonant Principal Eigenvalues

    Institute of Scientific and Technical Information of China (English)

    Tian Si ZHANG; De Ming ZHU

    2006-01-01

    Codimension-3 bifurcations of an orbit-flip homoclinic orbit with resonant principal eigenvalues are studied for a four-dimensional system. The existence, number, co-existence and non-coexistence of 1-homoclinic orbit, 1-periodic orbit, 2n-homoclinic orbit and 2n-periodic orbit are obtained. The bifurcation surfaces and existence regions are also given.

  10. Degenerate Orbit Flip Homoclinic Bifurcations with Higher Dimensions

    Institute of Scientific and Technical Information of China (English)

    Ran Chao WU; Jian Hua SUN

    2006-01-01

    Bifurcations of a degenerate homoclinic orbit with orbit flip in high dimensional system are existence and uniqueness of 1-homoclinic orbit and 1-periodic orbit are given. Also considered is the existence of 2-homoclinic orbit and 2-periodic orbit. In additon, the corresponding bifurcation surfaces are given.

  11. Student and Instructor Perceptions of a Flipped College Algebra Classroom

    Science.gov (United States)

    Jaster, Robert W.

    2017-01-01

    Each year about half a million students fail to make planned academic progress due to college algebra, hence the need for researchers to find ways of improving the quality of instruction in the course. Recent research suggests that flipping college algebra to allow time for active learning in the classroom may improve student performance. Also,…

  12. How do medical students prepare for flipped classrooms?

    NARCIS (Netherlands)

    Bouwmeester, RAM; de Kleijn, R.A.M.; ten Cate, TJ; van Rijen, HVM; Westerveld, HE

    A flipped classroom, an approach abandoning traditional lectures and having students come together to apply acquired knowledge, requires students to come to class well prepared. The nature of this preparation is currently being debated. Watching web lectures as a preparation has typically been

  13. Flipped Top-Down is Systematic Bottom-Up

    NARCIS (Netherlands)

    Zaytsev, V.; Sturm, A.; Clark, T.

    2016-01-01

    The paper presents an experience report in course design for a versatile group of computer science students where their needs were surfaced and met by the combination of strict top-down exposure to course material and the flipped classroom model of lecturing.

  14. Applying a learning design methodology in the flipped classroom approach – empowering teachers to reflect

    DEFF Research Database (Denmark)

    Triantafyllou, Evangelia; Kofoed, Lise; Purwins, Hendrik

    2016-01-01

    One of the recent developments in teaching that heavily relies on current technology is the “flipped classroom” approach. In a flipped classroom the traditional lecture and homework sessions are inverted. Students are provided with online material in order to gain necessary knowledge before class...... through flipped classroom designs. In order to discuss the opportunities arising by this approach, the different components of the Learning Design – Conceptual Map (LD-CM) are presented and examined in the context of the flipped classroom. It is shown that viewing the flipped classroom through the lens......, tools and resources used in specific flipped classroom models, and it can make educators more aware of the decisions that have to be taken and people who have to be involved when designing a flipped classroom. By using the LD-CM, this paper also draws attention to the importance of characteristics...

  15. The Ins and Outs of Lipid Flip-Flop.

    Science.gov (United States)

    Allhusen, John S; Conboy, John C

    2017-01-17

    Our current view of cellular membranes centers on the fluid-mosaic model, which envisions the cellular membrane as a "liquidlike" bilayer of lipids, cholesterol, and proteins that freely diffuse in two dimensions. In stark contrast, the exchange of materials between the leaflets of a bilayer was presumed to be prohibited by the large enthalpic barrier associated with translocating hydrophilic materials, such as a charged lipid headgroup, through the hydrophobic membrane core. This static picture with regard to lipid translocation (or "flip-flop" as it is affectionately known) has been a long-held belief in the study of membrane dynamics. The current accepted membrane model invokes specific protein flippase (inward moving), floppase (outward moving), and scramblase (bidirectional) enzymes that assist in the movement of lipids between the leaflets of cellular membranes. The low rate of protein-free lipid flip-flop has also been a cornerstone of our understanding of the bilateral organization of cellular membrane components, specifically the asymmetric distribution of lipid species found in the luminal and extracellular leaflets of the plasma membrane of eukaryotic cells. Much of the previous work contributing to our current understanding of lipid flip-flop has utilized fluorescent- or spin-labeled lipids. However, there is growing evidence that these lipid probes do not accurately convey the dynamics and thermodynamics of native (unlabeled) lipid motion. This Account summarizes our research efforts directed toward developing a deep physical and chemical understanding of protein-free lipid flip-flop in phospholipid membrane models using sum-frequency vibrational spectroscopy (SFVS). Our use of SFVS enables the direct measurement of native lipid flip-flop in model membranes. In particular, we have explored the kinetic rates and activation thermodynamics of lipid translocation as a means of deciphering the underlying chemical and physical directors governing this

  16. Packaging Technologies for 500C SiC Electronics and Sensors

    Science.gov (United States)

    Chen, Liang-Yu

    2013-01-01

    Various SiC electronics and sensors are currently under development for applications in 500C high temperature environments such as hot sections of aerospace engines and the surface of Venus. In order to conduct long-term test and eventually commercialize these SiC devices, compatible packaging technologies for the SiC electronics and sensors are required. This presentation reviews packaging technologies developed for 500C SiC electronics and sensors to address both component and subsystem level packaging needs for high temperature environments. The packaging system for high temperature SiC electronics includes ceramic chip-level packages, ceramic printed circuit boards (PCBs), and edge-connectors. High temperature durable die-attach and precious metal wire-bonding are used in the chip-level packaging process. A high temperature sensor package is specifically designed to address high temperature micro-fabricated capacitive pressure sensors for high differential pressure environments. This presentation describes development of these electronics and sensor packaging technologies, including some testing results of SiC electronics and capacitive pressure sensors using these packaging technologies.

  17. Assessment of the relationship between pre-chip and post-chip quality measures for Affymetrix GeneChip expression data

    Directory of Open Access Journals (Sweden)

    Augood Sarah J

    2006-04-01

    Full Text Available Abstract Background Gene expression microarray experiments are expensive to conduct and guidelines for acceptable quality control at intermediate steps before and after the samples are hybridised to chips are vague. We conducted an experiment hybridising RNA from human brain to 117 U133A Affymetrix GeneChips and used these data to explore the relationship between 4 pre-chip variables and 22 post-chip outcomes and quality control measures. Results We found that the pre-chip variables were significantly correlated with each other but that this correlation was strongest between measures of RNA quality and cRNA yield. Post-mortem interval was negatively correlated with these variables. Four principal components, reflecting array outliers, array adjustment, hybridisation noise and RNA integrity, explain about 75% of the total post-chip measure variability. Two significant canonical correlations existed between the pre-chip and post-chip variables, derived from MAS 5.0, dChip and the Bioconductor packages affy and affyPLM. The strongest (CANCOR 0.838, p Conclusion We have found that the post-chip variables having the strongest association with quantities measurable before hybridisation are those reflecting RNA integrity. Other aspects of quality, such as noise measures (reflecting the execution of the assay or measures reflecting data quality (outlier status and array adjustment variables are not well predicted by the variables we were able to determine ahead of time. There could be other variables measurable pre-hybridisation which may be better associated with expression data quality measures. Uncovering such connections could create savings on costly microarray experiments by eliminating poor samples before hybridisation.

  18. Polarizing a stored proton beam by spin-flip?

    Energy Technology Data Exchange (ETDEWEB)

    Oellers, Dieter Gerd Christian

    2010-04-15

    The present thesis discusses the extraction of the electron-proton spin-flip cross-section. The experimental setup, the data analysis and the results are pictured in detail. The proton is described by a QCD-based parton model. In leading twist three functions are needed. The quark distribution, the helicity distribution and the transversity distribution. While the first two are well-known, the transversity distribution is largely unknown. A self-sufficient measurement of the transversity is possible in double polarized proton-antiproton scattering. This rises the need of a polarized antiproton beam. So far spin filtering is the only tested method to produce a polarized proton beam, which may be capable to hold also for antiprotons. In-situ polarization build-up of a stored beam either by selective removal or by spin-flip of a spin-(1)/(2) beam is mathematically described. A high spin-flip cross-section would create an effective method to produce a polarized antiproton beam by polarized positrons. Prompted by conflicting calculations, a measurement of the spin-flip cross-section in low-energy electron-proton scattering was carried out. This experiment uses the electron beam of the electron cooler at COSY as an electron target. The depolarization of the stored proton beam is detected. An overview of the experiment is followed by detailed descriptions of the cycle setup, of the electron target and the ANKE silicon tracking telescopes acting as a beam polarimeter. Elastic protondeuteron scattering is the analyzing reaction. The event selection is depicted and the beam polarization is calculated. Upper limits of the two electron-proton spin-flip cross-sections {sigma} {sub parallel} and {sigma} {sub perpendicular} {sub to} are deduced using the likelihood method. (orig.)

  19. 电子封装、QFP和MCM热变形的实验及数值分析%Experimental and Numerical Analysis of Thermal Deformation of Electronic Packages,QFP and MCM

    Institute of Scientific and Technical Information of China (English)

    2006-01-01

    Moiré inteferometry and FEA (finite element analysis) were used to evaluate the thermal deformation of two electronic packages, QFP (quad flat package) and MCM (multi chip module).Thermal loading was applied by cooling the packages from 100℃ to room temperature (25℃). Moiré fringes were obtained on the cross sections of the packages to clarify the effect of the CTE (coefficient of thermal expansion) mismatch of the micro components, such as silicon, metal and resin. In QFP, the effects of packaging resin and PCB (printed circuit board) on the thermal deformation were investigated. The effect of location of three silicon chips in MCM was also examined.

  20. Packaging Concerns/Techniques for Large Devices

    Science.gov (United States)

    Sampson, Michael J.

    2009-01-01

    This slide presentation reviews packaging challenges and options for electronic parts. The presentation includes information about non-hermetic packages, space challenges for packaging and complex package variations.

  1. Flipping the Learning: An Investigation into the Use of the Flipped Classroom Model in an Introductory Teaching Course

    Science.gov (United States)

    Vaughan, Michelle

    2014-01-01

    With a classroom full of millennial learners, it is essential that teacher educators adjust their pedagogy to meet their students' needs. This study explores the use of a flipped classroom model to engage preservice teachers in an Introduction to the Teaching Profession course. In addition, it explores the need for teacher education…

  2. Element nodes of sports equipment double back flip factions and double back flip hunched performed gymnast in floor exercise

    Directory of Open Access Journals (Sweden)

    Potop V.A.

    2014-04-01

    Full Text Available Purpose: to identify the node elements of sports equipment double back somersault tuck and double back flip bent. To compare the two types of nodes for double somersault. Material : the study involved eight gymnasts (age 12 - 14 years. All finalists in the competition floor exercise - reserve team Romania. The method of video - computer research and method of postural orientation movements. Results : identified nodal elements of sports equipment double back somersault tuck and double back flip bent. In the preparatory phase of motor actions - launcher body posture for reaching is repulsive to flip. In the phase of basic motor action - animation body postures (double back somersault tuck and bent (bent double back flip. Exercises are performed on the ascending and descending parts of the flight path of the demonstration of individual maximum lift height common center of mass. In the final phase of motor actions - final body posture - steady landing. Conclusions : indicators of key elements of sports equipment acrobatic exercises contain new scientific facts kinematic and dynamic structures of motor actions. They are necessary for the development of modern training programs acrobatic exercises in step specialized base preparation.

  3. PROSPECTS OF POLYMER PACKAGING MATERIALS

    Directory of Open Access Journals (Sweden)

    V. A. Sedykh

    2012-01-01

    Full Text Available The main types of materials used in the manufacture of packaging. Analyzed trends in further development of packaging materials. Shows how to improve the quality of plastic packaging materials in today's market.

  4. Consumer response to packaging design

    NARCIS (Netherlands)

    Steenis, Nigel D.; Herpen, van Erica; Lans, van der Ivo A.; Ligthart, Tom N.; Trijp, van Hans C.M.

    2017-01-01

    Building on theories of cue utilization, this paper investigates whether and how packaging sustainability influences consumer perceptions, inferences and attitudes towards packaged products. A framework is tested in an empirical study among 249 students using soup products varying in packaging

  5. Packaging Printing Today

    Directory of Open Access Journals (Sweden)

    Stanislav Bolanča

    2015-12-01

    Full Text Available Printing packaging covers today about 50% of all the printing products. Among the printing products there are printing on labels, printing on flexible packaging, printing on folding boxes, printing on the boxes of corrugated board, printing on glass packaging, synthetic and metal ones. The mentioned packaging are printed in flexo printing technique, offset printing technique, intaglio halftone process, silk – screen printing, ink ball printing, digital printing and hybrid printing process. The possibilities of particular printing techniques for optimal production of the determined packaging were studied in the paper. The problem was viewed from the technological and economical aspect. The possible printing quality and the time necessary for the printing realization were taken as key parameters. An important segment of the production and the way of life is alocation value and it had also found its place in this paper. The events in the field of packaging printing in the whole world were analyzed. The trends of technique developments and the printing technology for packaging printing in near future were also discussed.

  6. Pixel detector readout chip

    CERN Multimedia

    1991-01-01

    Close-up of a pixel detector readout chip. The photograph shows an aera of 1 mm x 2 mm containing 12 separate readout channels. The entire chip contains 1000 readout channels (around 80 000 transistors) covering a sensitive area of 8 mm x 5 mm. The chip has been mounted on a silicon detector to detect high energy particles.

  7. Hermeticity of electronic packages

    CERN Document Server

    Greenhouse, Hal; Romenesco, Bruce

    2011-01-01

    This is a book about the integrity of sealed packages to resist foreign gases and liquids penetrating the seal or an opening (crack) in the packageùespecially critical to the reliability and longevity of electronics. The author explains how to predict the reliability and the longevity of the packages based on leak rate measurements and the assumptions of impurities. Non-specialists in particular will benefit from the author's long involvement in the technology. Hermeticity is a subject that demands practical experience, and solving one problem does not necessarily give one the background to so

  8. Optoelectronic packaging: A review

    Energy Technology Data Exchange (ETDEWEB)

    Carson, R.F.

    1993-09-01

    Optoelectronics and photonics hold great potential for high data-rate communication and computing. Wide using in computing applications was limited first by device technologies and now suffers due to the need for high-precision, mass-produced packaging. The use of phontons as a medium of communication and control implies a unique set of packaging constraints that was not present in traditional telecommunications applications. The state-of-the-art in optoelectronic packaging is now driven by microelectric techniques that have potential for low cost and high volume manufacturing.

  9. Hermeticity of electronic packages

    CERN Document Server

    Greenhouse, Hal

    2000-01-01

    This is a book about the integrity of sealed packages to resist foreign gases and liquids penetrating the seal or an opening (crack) in the package-especially critical to the reliability and longevity of electronics. The author explains how to predict the reliability and the longevity of the packages based on leak rate measurements and the assumptions of impurities. Non-specialists in particular will benefit from the author's long involvement in the technology. Hermeticity is a subject that demands practical experience, and solving one problem does not necessarily give one the background to so

  10. 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

  11. 3-D readout-electronics packaging for high-bandwidth massively paralleled imager

    Science.gov (United States)

    Kwiatkowski, Kris; Lyke, James

    2007-12-18

    Dense, massively parallel signal processing electronics are co-packaged behind associated sensor pixels. Microchips containing a linear or bilinear arrangement of photo-sensors, together with associated complex electronics, are integrated into a simple 3-D structure (a "mirror cube"). An array of photo-sensitive cells are disposed on a stacked CMOS chip's surface at a 45.degree. angle from light reflecting mirror surfaces formed on a neighboring CMOS chip surface. Image processing electronics are held within the stacked CMOS chip layers. Electrical connections couple each of said stacked CMOS chip layers and a distribution grid, the connections for distributing power and signals to components associated with each stacked CSMO chip layer.

  12. Broad Frequency LTCC Vertical Interconnect Transition for Multichip Modules and System on Package Applications

    Science.gov (United States)

    Decrossas, Emmanuel; Glover, Michael D.; Porter, Kaoru; Cannon, Tom; Mantooth, H. Alan; Hamilton, M. C.

    2013-01-01

    Various stripline structures and flip chip interconnect designs for high-speed digital communication systems implemented in low temperature co-fired ceramic (LTCC) substrates are studied in this paper. Specifically, two different transition designs from edge launch 2.4 millimeter connectors to stripline transmission lines embedded in LTCC are discussed. After characterizing the DuPont (sup trademark) 9K7 green tape, different designs are proposed to improve signal integrity for high-speed digital data. The full-wave simulations and experimental data validate the presented designs over a broad frequency band from Direct Current to 50 gigahertz and beyond.

  13. Broad Frequency LTCC Vertical Interconnect Transition for Multichip Modules and System on Package Applications

    Science.gov (United States)

    Decrossas, Emmanuel; Glover, Michael D.; Porter, Kaoru; Cannon, Tom; Mantooth, H. Alan; Hamilton, M. C.

    2013-01-01

    Various stripline structures and flip chip interconnect designs for high-speed digital communication systems implemented in low temperature co-fired ceramic (LTCC) substrates are studied in this paper. Specifically, two different transition designs from edge launch 2.4 millimeter connectors to stripline transmission lines embedded in LTCC are discussed. After characterizing the DuPont (sup trademark) 9K7 green tape, different designs are proposed to improve signal integrity for high-speed digital data. The full-wave simulations and experimental data validate the presented designs over a broad frequency band from Direct Current to 50 gigahertz and beyond.

  14. System on a Chip (SoC) Overview

    Science.gov (United States)

    LaBel, Kenneth A.

    2010-01-01

    System-on-a-chip or system on chip (SoC or SOC) refers to integrating all components of a computer or other electronic system into a single integrated circuit (chip). It may contain digital, analog, mixed-signal, and often radio-frequency functions all on a single chip substrate. Complexity drives it all: Radiation tolerance and testability are challenges for fault isolation, propagation, and validation. Bigger single silicon die than flown before and technology is scaling below 90nm (new qual methods). Packages have changed and are bigger and more difficult to inspect, test, and understand. Add in embedded passives. Material interfaces are more complex (underfills, processing). New rules for board layouts. Mechanical and thermal designs, etc.

  15. Targeting the Anti-Apoptotic Protein c-FLIP for Cancer Therapy

    Energy Technology Data Exchange (ETDEWEB)

    Safa, Ahmad R., E-mail: asafa@iupui.edu [Department of Pharmacology and Toxicology, Indiana University School of Medicine, 980 W. Walnut Street, R3-C524, Indianapolis, IN 46202 (United States); Indiana University Simon Cancer Center, Indiana University School of Medicine, 980 W. Walnut Street, R3-C524, Indianapolis, IN 46202 (United States); Pollok, Karen E. [Department of Pharmacology and Toxicology, Indiana University School of Medicine, 980 W. Walnut Street, R3-C524, Indianapolis, IN 46202 (United States); Indiana University Simon Cancer Center, Indiana University School of Medicine, 980 W. Walnut Street, R3-C524, Indianapolis, IN 46202 (United States); Herman B. Wells Center for Pediatric Research, 980 W. Walnut Street, R3-C524, Indianapolis, IN 46202 (United States)

    2011-03-29

    Cellular FLICE (FADD-like IL-1beta-converting enzyme)-inhibitory protein (c-FLIP) is a major resistance factor and critical anti-apoptotic regulator that inhibits tumor necrosis factor-alpha (TNF-alpha), Fas-L, and TNF-related apoptosis-inducing ligand (TRAIL)-induced apoptosis as well as chemotherapy-triggered apoptosis in malignant cells. c-FLIP is expressed as long (c-FLIP{sub L}), short (c-FLIP{sub S}), and c-FLIP{sub R} splice variants in human cells. c-FLIP binds to FADD and/or caspase-8 or -10 in a ligand-dependent and-independent fashion, which in turn prevents death-inducing signaling complex (DISC) formation and subsequent activation of the caspase cascade. Moreover, c-FLIP{sub L} and c-FLIP{sub S} are known to have multifunctional roles in various signaling pathways, as well as activating and/or upregulating several cytoprotective signaling molecules. Upregulation of c-FLIP has been found in various tumor types, and its downregulation has been shown to restore apoptosis triggered by cytokines and various chemotherapeutic agents. Hence, c-FLIP is an important target for cancer therapy. For example, small interfering RNAs (siRNAs) that specifically knockdown the expression of c-FLIP{sub L} in diverse human cancer cell lines augmented TRAIL-induced DISC recruitment and increased the efficacy of chemotherapeutic agents, thereby enhancing effector caspase stimulation and apoptosis. Moreover, small molecules causing degradation of c-FLIP as well as decreasing mRNA and protein levels of c-FLIP{sub L} and c-FLIP{sub S} splice variants have been found, and efforts are underway to develop other c-FLIP-targeted cancer therapies. This review focuses on (1) the functional role of c-FLIP splice variants in preventing apoptosis and inducing cytokine and drug resistance; (2) the molecular mechanisms that regulate c-FLIP expression; and (3) strategies to inhibit c-FLIP expression and function.

  16. Evaluation of thermal resistance constitution for packaged AlGaN/GaN high electron mobility transistors by structure function method

    Institute of Scientific and Technical Information of China (English)

    Zhang Guang-Chen; Feng Shi-Wei; Zhou Zhou; Li Jing-Wan; Guo Chun-Sheng

    2011-01-01

    The evaluation of thermal resistance constitution for packaged AlGaN/GaN high electron mobility transistor (HEMT) by structure function method is proposed in this paper. The evaluation is based on the transient heating measurement of the AlGaN/GaN HEMT by pulsed electrical temperature sensitive parameter method. The extracted chip-level and package-level thermal resistances of the packaged multi-finger AlGaN/GaN HEMT with 400-μn SiC substrate are 22.5 K/W and 7.2 K/W respectively, which provides a non-invasive method to evaluate the chip-level thermal resistance of packaged AlGaN/GaN HEMTs. It is also experimentally proved that the extraction of the chip-level thermal resistance by this proposed method is not influenced by package form of the tested device and temperature boundary condition of measurement stage.

  17. Dual Use Packaging Project

    Data.gov (United States)

    National Aeronautics and Space Administration — NASA calculation that over a kg of packaging waste are generated per day for a 6 member crew. This represents over 1.5 metric tons of waste during a Mars mission....

  18. FLEXIBLE FOOD PACKAGING LABORATORY

    Data.gov (United States)

    Federal Laboratory Consortium — This laboratory contains equipment to fabricate and test prototype packages of many types and sizes (e.g., bags, pouches, trays, cartons, etc.). This equipment can...

  19. London 2012 packaging guidelines

    OpenAIRE

    2013-01-01

    These guidelines are intended to provide supplemental advice to suppliers and licensees regarding the provisions of the LOCOG Sustainable Sourcing Code that relate to packaging design and materials selection.

  20. A novel role of c-FLIP protein in regulation of ER stress response.

    Science.gov (United States)

    Conti, Silvia; Petrungaro, Simonetta; Marini, Elettra Sara; Masciarelli, Silvia; Tomaipitinca, Luana; Filippini, Antonio; Giampietri, Claudia; Ziparo, Elio

    2016-09-01

    Cellular-Flice-like inhibitory protein (c-FLIP) is an apoptosis modulator known to inhibit the extrinsic apoptotic pathway thus blocking Caspase-8 processing in the Death Inducing Signalling Complex (DISC). We previously demonstrated that c-FLIP localizes at the endoplasmic reticulum (ER) and that c-FLIP-deficient mouse embryonic fibroblasts (MEFs) display an enlarged ER morphology. In the present study, we have addressed the consequences of c-FLIP ablation in the ER stress response by investigating the effects of pharmacologically-induced ER stress in Wild Type (WT) and c-FLIP-/- MEFs. Surprisingly, c-FLIP-/- MEFs were found to be strikingly more resistant than WT MEFs to ER stress-mediated apoptosis. Analysis of Unfolded Protein Response (UPR) pathways revealed that Pancreatic ER Kinase (PERK) and Inositol-Requiring Enzyme 1 (IRE1) branch signalling is compromised in c-FLIP-/- cells when compared with WT cells. We found that c-FLIP modulates the PERK pathway by interfering with the activity of the serine threonine kinase AKT. Indeed, c-FLIP-/- MEFs display higher levels of active AKT than WT MEFs upon ER stress, while treatment with a specific AKT inhibitor of c-FLIP-/- MEFs subjected to ER stress restores the PERK but not the IRE1 pathway. Importantly, the AKT inhibitor or dominant negative AKT transfection sensitizes c-FLIP-/- cells to ER stress-induced cell death while the expression of a constitutively active AKT reduces WT cells sensitivity to ER stress-induced death. Thus, our results demonstrate that c-FLIP modulation of AKT activity is crucial in controlling PERK signalling and sensitivity to ER stress, and highlight c-FLIP as a novel molecular player in PERK and IRE1-mediated ER stress response.