Sample records for solder bump-bonded dummy

  1. Low-cost bump bonding activities at CERN

    Vaehaenen, S; Tick, T; Campbell, M, E-mail: Sami.vaehaenen@cern.c [CERN, PH-ESE 1211 Geneva 23 (Switzerland)


    Conventional bumping processes used in the fabrication of hybrid pixel detectors for High Energy Physics (HEP) experiments use electroplating for Under Bump Metallization (UBM) and solder bump deposition. This process is laborious, involves time consuming photolithography and can only be performed using whole wafers. Electroplating has been found to be expensive when used for the low volumes which are typical of HEP experiments. In the low-cost bump bonding development work, electroless deposition technology of UBM is studied as an alternative to the electroplating process in the bump size / pitch window beginning from 20 {mu}m / 50 {mu}m. Electroless UBM deposition used in combination with solder transfer techniques has the potential to significantly lower the cost of wafer bumping without requiring increased wafer volumes. A test vehicle design of sensor and readout chip, having daisy chains and Kelvin bump structures, was created to characterize the flip chip process with electroless UBM. Two batches of test vehicle wafers were manufactured with different bump pad metallization. Batch no. 1 had AlSi(1%) metallization, which is similar to the one used on sensor wafers, and Batch no. 2 had AlSi(2%)Cu(1%) metallization, which is very similar to the one used on readout wafers. Electroless UBMs were deposited on both wafer batches. In addition, electroplated Ni UBM and SnPb solder bumps were grown on the test sensor wafers. Test assemblies were made by flip chip bonding the solder-bumped test sensors against the test readout chips with electroless UBMs. Electrical yields and individual joint resistances were measured from assemblies, and the results were compared to a well known reference technique based on electroplated solder bumps structures on both chips. The electroless UBMs deposited on AlSi(2%)Cu(1%) metallization showed excellent electrical yields and small tolerances in individual joint resistance. The results from the UBMs deposited on AlSi(1

  2. Process for Patterning Indium for Bump Bonding

    Denis, Kevin


    An innovation was created for the Cosmology Large Angular Scale Surveyor for integration of low-temperature detector chips with a silicon backshort and a silicon photonic choke through flipchip bonding. Indium bumps are typically patterned using liftoff processes, which require thick resist. In some applications, it is necessary to locate the bumps close to high-aspect-ratio structures such as wafer through-holes. In those cases, liftoff processes are challenging, and require complicated and time-consuming spray coating technology if the high-aspect-ratio structures are delineated prior to the indium bump process. Alternatively, processing the indium bumps first is limited by compatibility of the indium with subsequent processing. The present invention allows for locating bumps arbitrarily close to multiple-level high-aspect-ratio structures, and for indium bumps to be formed without liftoff resist. The process uses the poor step coverage of indium deposited on a silicon wafer that has been previously etched to delineate the location of the indium bumps. The silicon pattern can be processed through standard lithography prior to adding the high-aspect-ratio structures. Typically, high-aspectratio structures require a thick resist layer so this layer can easily cover the silicon topography. For multiple levels of topography, the silicon can be easily conformally coated through standard processes. A blanket layer of indium is then deposited onto the full wafer; bump bonding only occurs at the high points of the topography.

  3. The first bump-bonded pixel detectors on CVD diamond

    Adam, W.; Bauer, C.; Berdermann, E.; Bergonzo, P.; Bogani, F.; Borchi, E.; Brambilla, A.; Bruzzi, M.; Colledani, C.; Conway, J.; Dabrowski, W.; Delpierre, P.; Deneuville, A.; Dulinski, W.; Eijk, B. van; Fallou, A.; Fizzotti, F.; Foulon, F.; Friedl, M.; Gan, K.K.; Gheeraert, E.; Grigoriev, E.; Hallewell, G.; Hall-Wilton, R.; Han, S.; Hartjes, F.; Hrubec, J.; Husson, D.; Kagan, H.; Kania, D.; Kaplon, J.; Karl, C.; Kass, R.; Krammer, M.; Logiudice, A.; Lu, R.; Manfredi, P.F.; Manfredotti, C.; Marshall, R.D.; Meier, D.; Mishina, M.; Oh, A.; Palmieri, V.G.; Pan, L.S.; Peitz, A.; Pernicka, M.; Pirollo, S.; Polesello, P.; Pretzl, K.; Re, V.; Riester, J.L.; Roe, S.; Roff, D.; Rudge, A.; Schnetzer, S.; Sciortino, S.; Speziali, V.; Stelzer, H.; Steuerer, J.; Stone, R.; Tapper, R.J.; Tesarek, R.; Trawick, M.; Trischuk, W. E-mail:; Turchetta, R.; Vittone, E.; Wagner, A.; Walsh, A.M.; Wedenig, R.; Weilhammer, P.; Zeuner, W.; Ziock, H.; Zoeller, M.; Charles, E.; Ciocio, A.; Dao, K.; Einsweiler, K.; Fasching, D.; Gilchriese, M.; Joshi, A.; Kleinfelder, S.; Milgrome, O.; Palaio, N.; Richardson, J.; Sinervo, P.; Zizka, G


    Diamond is a nearly ideal material for detecting ionising radiation. Its outstanding radiation hardness, fast charge collection and low leakage current allow it to be used in high radiation environments. These characteristics make diamond sensors particularly appealing for use in the next generation of pixel detectors. Over the last year, the RD42 collaboration has worked with several groups that have developed pixel readout electronics in order to optimise diamond sensors for bump-bonding. This effort resulted in an operational diamond pixel sensor that was tested in a pion beam. We demonstrate that greater than 98% of the channels were successfully bump-bonded and functioning. The device shows good overall hit efficiency as well as clear spatial hit correlation to tracks measured in a silicon reference telescope. A position resolution of 14.8 {mu}m was observed, consistent with expectations given the detector pitch.

  4. Bump Bonding Using Metal-Coated Carbon Nanotubes

    Lamb, James L.; Dickie, Matthew R.; Kowalczyk, Robert S.; Liao, Anna; Bronikowski, Michael J.


    Bump bonding hybridization techniques use arrays of indium bumps to electrically and mechanically join two chips together. Surface-tension issues limit bump sizes to roughly as wide as they are high. Pitches are limited to 50 microns with bumps only 8-14 microns high on each wafer. A new process uses oriented carbon nanotubes (CNTs) with a metal (indium) in a wicking process using capillary actions to increase the aspect ratio and pitch density of the connections for bump bonding hybridizations. It merges the properties of the CNTs and the metal bumps, providing enhanced material performance parameters. By merging the bumps with narrow and long CNTs oriented in the vertical direction, higher aspect ratios can be obtained if the metal can be made to wick. Possible aspect ratios increase from 1:1 to 20:1 for most applications, and to 100:1 for some applications. Possible pitch density increases of a factor of 10 are possible. Standard capillary theory would not normally allow indium or most other metals to be drawn into the oriented CNTs, because they are non-wetting. However, capillary action can be induced through the ability to fabricate oriented CNT bundles to desired spacings, and the use of deposition techniques and temperature to control the size and mobility of the liquid metal streams and associated reservoirs. This hybridization of two technologies (indium bumps and CNTs) may also provide for some additional benefits such as improved thermal management and possible current density increases.

  5. Apparatus for Precise Indium-Bump Bonding of Microchips

    Wild, Larry; Mulder, Jerry; Alvarado, Nicholas


    An improved apparatus has been designed and built for use in precise positioning and pressing of a microchip onto a substrate (which could, optionally, be another microchip) for the purpose of indium-bump bonding. The apparatus (see figure) includes the following: A stereomicroscope, A stage for precise positioning of the microchip in rotation angle (theta) about the nominally vertical pressing axis and in translation along two nominally horizontal coordinate axes (x and y), and An actuator system that causes a bonding tip to press the microchip against the substrate with a precisely controlled force. In operation, the microscope and the stage are used to position the microchip under the bonding tip and to align the indium bumps on the chip and the substrate, then the actuator system is used to apply a prescribed bonding force for a prescribed time. The improved apparatus supplants a partly similar prior apparatus that operated with less precision and repeatability, producing inconsistent and unreliable bonds. Results of the use of the prior apparatus included broken microchips, uneven bonds, and bonds characterized, variously, by overcompression or undercompression. In that apparatus, the bonding force was generated and controlled by use of a micrometer head positioned over the center of a spring-loaded scale, and the force was applied to the microchip via the scale, which was equipped for digital readout of the force. The inconsistency of results was attributed to the following causes: It was not possible to control the bonding force with sufficient precision or repeatability. Particularly troublesome was the inability to control the force at levels less than the weight of 150 g. Excessive compliance in the spring-loaded scale, combined with deviations from parallelarity of the substrate and bonding-tip surfaces, gave rise to nonuniformity in the pressure applied to the microchip, thereby generating excessive stresses and deformations in the microchip. In the

  6. \\title{Low-Cost Bump-Bonding Processes for High Energy Physics Pixel Detectors}

    Caselle, Michele; Colombo, Fabio; Dierlamm, Alexander Hermann; Husemann, Ulrich; Kudella, Simon; Weber, M


    In the next generation of collider experiments detectors will be challenged by unprecedented particle fluxes. Thus large detector arrays of highly pixelated detectors with minimal dead area at reasonable costs are required. Bump-bonding of pixel detectors has been shown to be a major cost-driver. KIT is one of the production centers of the CMS barrel pixel detector for the Phase I Upgrade. In this contribution the SnPb bump-bonding process and the production yield is reported. In parallel to the production of the new CMS pixel detector, several alternatives to the expensive photolithography electroplating/electroless metal deposition technologies are developing. Recent progress and challenges faced in the development of bump-bonding technology based on gold-stud bonding by thin ($15\\,\\rm{\\mu m}$) gold wire is presented. This technique allows producing metal bumps with diameters down to $30\\,\\rm{\\mu m}$ without using photolithography processes, which are typically required to provide suitable under bu...

  7. Soldering handbook

    Vianco, Paul T


    Contains information related to soldering processes, and solder joint performance and reliability. Covers soldering fundamentals, technology, materials, substrate materials, fluxes, pastes, assembly processes, inspection, and environment. Covers today's advanced joining applications and emphasizes new materials, including higher strength alloys; predictive performance; computer modeling; advanced inspection techniques; new processing concepts, including laser heating; and the resurgence in ultrasonic soldering.

  8. Wave soldering with Pb-free solders

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


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

  9. Bump bonding of pixel systems

    Lozano, M. E-mail:; Cabruja, E.; Collado, A.; Santander, J.; Ullan, M


    A pixel detector consists of an array of radiation sensing elements which is connected to an electronic read-out unit. Many different ways of making this connection between these two different devices are currently being used or considered to be used in the next future. Bonding techniques such as flip chip technology can present real advantages because they allow very fine pitch and a high number of I/Os. This paper presents a review of the different flip chip technologies available and their suitability for manufacturing pixel detectors. The particular problems concerning testing of pixel detectors and thermal issues related to them are pointed out.

  10. Bump bonding of pixel systems

    Lozano, M; Collado, A; Santander, J; Ullán, M


    A pixel detector consists of an array of radiation sensing elements which is connected to an electronic read-out unit. Many different ways of making this connection between these two different devices are currently being used or considered to be used in the next future. Bonding techniques such as flip chip technology can present real advantages because they allow very fine pitch and a high number of I/Os. This paper presents a review of the different flip chip technologies available and their suitability for manufacturing pixel detectors. The particular problems concerning testing of pixel detectors and thermal issues related to them are pointed out.

  11. Soldering in electronics assembly

    Judd, Mike


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

  12. Numeracy Tests For Dummies

    Beveridge, Colin


    The easy way to get practice and excel at numeracy tests Whether you're looking for a new job, applying to certain university courses, or attempting to join the military, you're increasingly likely to face a numeracy test as part of the screening process. And the only way to prepare for a numeracy test is practise. Numeracy Tests For Dummies is an accessible one-stop guide to pass these test. Featuring expert advice, instruction, review, and plenty of practise, Numeracy Tests For Dummies will help you succeed. Numeracy Tests For Dummies contains instruction and revision on:Basic mathematical k

  13. Excel 2010 for dummies

    Harvey, Greg


    The bestselling Excel book on the market, updated for Excel 2010 As the world's leading spreadsheet application, Excel has a huge user base. The release of Office 2010 brings major changes to Excel, so Excel For Dummies comes to the rescue once more! In the friendly and non-threatening For Dummies style, this popular guide shows beginners how to get up and running with Excel and helps more experienced users get comfortable with new features.Excel is the number one spreadsheet application worldwide, and Excel For Dummies is the number one guide to using i

  14. Investigation of Sn-Pb solder bumps of prototype photo detectors for the LHCb experiment

    Delsante, M L; Arnau-Izquierdo, G


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

  15. Statistics Essentials For Dummies

    Rumsey, Deborah


    Statistics Essentials For Dummies not only provides students enrolled in Statistics I with an excellent high-level overview of key concepts, but it also serves as a reference or refresher for students in upper-level statistics courses. Free of review and ramp-up material, Statistics Essentials For Dummies sticks to the point, with content focused on key course topics only. It provides discrete explanations of essential concepts taught in a typical first semester college-level statistics course, from odds and error margins to confidence intervals and conclusions. This guide is also a perfect re

  16. C++ for dummies

    Davis , Stephen R


    The best-selling C++ For Dummies book makes C++ easier! C++ For Dummies, 7th Edition is the best-selling C++ guide on the market, fully revised for the 2014 update. With over 60% new content, this updated guide reflects the new standards, and includes a new Big Data focus that highlights the use of C++ among popular Big Data software solutions. The book provides step-by-step instruction from the ground up, helping beginners become programmers and allowing intermediate programmers to sharpen their skills. The companion website provides all code mentioned in the text, an updated GNU_C++, the new

  17. Kindle Paperwhite for dummies

    Nicoll, Leslie H


    Get the inside story on the all-new Kindle Paperwhite with help from For Dummies It reads like a book, but it's so much more. The Kindle Paperwhite is the ultimate e-reader, and this updated edition of Kindle Paperwhite For Dummies is your ultimate guide to getting more from this one-of-a-kind device. You'll learn to set up your Paperwhite, adjust the font to your liking, find your favorite books, magazines, and newspapers, and sync your Kindle content across devices before moving on to new Paperwhite features like Kindle FreeTime, Goodreads integration, Vocabulary Builder, In-line Footnotes

  18. Physics II for dummies

    Holzner, Steven


    A plain-English guide to advanced physics. Does just thinking about the laws of motion make your head spin? Does studying electricity short your circuits? Physics II For Dummies walks you through the essentials and gives you easy-to-understand and digestible guidance on this often intimidating course. Thanks to this book, you don?t have to be Einstein to understand physics. As you learn about mechanical waves and sound, forces and fields, electric potential and electric energy, and much more, you?ll appreciate the For Dummies law: The easier we make it, the faster you'll understand it!

  19. Dreamweaver CC for dummies

    Warner, Janine


    Turn your wonderful website dreams into robust realities with the help of Dreamweaver CC For Dummies! Creating dynamic websites is easy with Dreamweaver CC and this friendly, full-color guide. Updated for the latest version of Adobe's world-renowned web development tool, Dreamweaver CC For Dummies covers all aspects of creating websites, from understanding web design basics to using style sheets, integrating multimedia, implementing responsive design, testing and publishing your sites, and more. With the professional guidance of Web design expert Jan

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    Mazet, Veronique


    The easy way to master French grammar French Grammar For Dummies is a logical extension and complement to the successful language learning book, French For Dummies. In plain English, it teaches you the grammatical rules of the French language, including parts of speech, sentence construction, pronouns, adjectives, punctuation, stress and verb tenses, and moods. Throughout the book, you get plenty of practice opportunities to help you on your goal of mastering basic French grammar and usage. Grasp the grammatical rules of French including parts of speech, sentenc

  1. Statistics & probaility for dummies

    Rumsey, Deborah J


    Two complete eBooks for one low price! Created and compiled by the publisher, this Statistics I and Statistics II bundle brings together two math titles in one, e-only bundle. With this special bundle, you'll get the complete text of the following two titles: Statistics For Dummies, 2nd Edition  Statistics For Dummies shows you how to interpret and critique graphs and charts, determine the odds with probability, guesstimate with confidence using confidence intervals, set up and carry out a hypothesis test, compute statistical formulas, and more. Tra

  2. Cloud storage for dummies

    Xu, Linda; Loughlin, Tanya


    Understand cloud computing and save your organization time and money! Cloud computing is taking IT by storm, but what is it and what are the benefits to your organization? Hitachi Data Systems' Cloud Storage For Dummies provides all the answers, With this book, you discover a clear explanation of cloud storage, and tips for how to choose the right type of cloud storage for your organization's needs. You also find out how cloud storage can free up valuable IT resources, saving time and money. Cloud Storage For Dummies presents useful information on setting up a

  3. Physics Essentials For Dummies

    Holzner, Steven


    For students who just need to know the vital concepts of physics, whether as a refresher, for exam prep, or as a reference, Physics Essentials For Dummies is a must-have guide. Free of ramp-up and ancillary material, Physics Essentials For Dummies contains content focused on key topics only. It provides discrete explanations of critical concepts taught in an introductory physics course, from force and motion to momentum and kinetics. This guide is also a perfect reference for parents who need to review critical physics concepts as they help high school students with homework assignments, as we

  4. Circuit analysis for dummies

    Santiago, John


    Circuits overloaded from electric circuit analysis? Many universities require that students pursuing a degree in electrical or computer engineering take an Electric Circuit Analysis course to determine who will ""make the cut"" and continue in the degree program. Circuit Analysis For Dummies will help these students to better understand electric circuit analysis by presenting the information in an effective and straightforward manner. Circuit Analysis For Dummies gives you clear-cut information about the topics covered in an electric circuit analysis courses to help

  5. Physics I for dummies

    Holzner, Steven


    The fun and easy way to get up to speed on the basic concepts of physics For high school and undergraduate students alike, physics classes are recommended or required courses for a wide variety of majors, and continue to be a challenging and often confusing course. Physics I For Dummies tracks specifically to an introductory course and, keeping with the traditionally easy-to-follow Dummies style, teaches you the basic principles and formulas in a clear and concise manner, proving that you don't have to be Einstein to understand physics!

  6. Matlab for dummies

    Sizemore, Jim


    Plot graphs, solve equations, and write code in a flash! If you work in a STEM field, chances are you'll be using MATLAB on a daily basis. MATLAB is a popular and powerful computational tool and this book provides everything you need to start manipulating and plotting your data. MATLAB has rapidly become the premier data tool, and MATLAB For Dummies is a comprehensive guide to the fundamentals. MATLAB For Dummies guides you through this complex computational language from installation to visualization to automation.Learn MATLAB's language fundamentals including syntax, operators, and data type

  7. Solidworks for dummies

    Jankowski, Greg


    Whether it's your first venture into 3D technical drawing software or you're switching to SolidWorks from something else, you're probably excited about what this CAD program has to offer.   Chances are, you figure it's going to take awhile to get the hang of it before you can begin cranking out those perfectly precise 3D designs. SolidWorks For Dummies, 2nd Edition, can help you dramatically shorten that get-acquainted period! SolidWorks For Dummies, 2nd Edition will help you get up and running quickly on the leading 3D technical drawing software. You'll s

  8. Word 2003 for dummies

    Gookin, Dan


    Want to write great looking documents but can't seem to get ahandle on paragraph structuring? Unfamiliar with some of thebuttons and functions on your menu bar? Need to add page numbersfor a paper but can't find the controls? Word 2003 ForDummies will show you the quick and easy way to navigatethrough the trickiness of Microsoft Word. This book will be yourcomprehensive guide to using this word processor like a pro. Word 2003 For Dummies shows you all the essentials ofbuilding, reviewing, and adding cool new features to Worddocuments. No wonder the previous editions sold over 1.7 millioncopie

  9. Windows 10 for dummies

    Rathbone, Andy


    The fast and easy way to get up and running with Windows 10 Windows 10 For Dummies covers the latest version of Windows and gets you up and running with the changes and new features you'll find in this updated operating system. Packed with time-saving tips to help you get the most out of the software, this helpful Windows 10 guide shows you how to manage Windows tasks like navigating the interface with a mouse or touchscreen, connecting to the web, and troubleshooting problems and making quick fixes. Assuming no prior knowledge of the software, Windows 10 For Dummies addresses the updates to

  10. Scrivener for dummies

    Hernandez, Gwen


    No matter what you want to write, Scrivener makes it easier. Whether you’re a planner, a seat-of-the-pants writer, or something in between, Scrivener provides tools for every stage of the writing process. Scrivener For Dummies walks you step-by-step through this popular writing software’s best features. This friendly For Dummies  guide starts with the basics, but even experienced scriveners will benefit from the helpful tips for getting more from their favourite writing software. Walks you through customizing project templates for your

  11. Solderability test system

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


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

  12. Solderability test system

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


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

  13. Quantum physics for dummies

    Holzner, Steve


    Quantum Physics For Dummies, Revised Edition helps make quantum physics understandable and accessible. From what quantum physics can do for the world to understanding hydrogen atoms, readers will get complete coverage of the subject, along with numerous examples to help them tackle the tough equations. Compatible with classroom text books and courses, Quantum Physics For Dummies, Revised Edition lets students study at their own paces and helps them prepare for graduate or professional exams. Coverage includes: The Schrodinger Equation and its Applications The Foundations of Quantum Physics Vector Notation Spin Scattering Theory, Angular Momentum, and more From the Back Cover Your plain-English guide to understanding and working with the micro world Quantum physics -- also called quantum mechanics or quantum field theory -- can be daunting for even the most dedicated student or enthusiast of science, math, or physics. This friendly, concise guide makes this challenging subject understandable and accessible, fr...

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

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


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

  15. Lead-free solder

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


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

  16. Removing Dross From Molten Solder

    Webb, Winston S.


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

  17. Tumblr for dummies

    Jenkins, Sue


    Create a Tumblelog and start posting--this fun, portable guide shows you how Tumblr may be a microblogging platform, but there's nothing micro about it. There's no limit to what you can post in your blog--from text, photos, and links to audio, video, slideshows, and more. Now you can join the over 28 million Tumblelogs on Tumblr with this handy, portable guide. In the popular, For Dummies, easy-access style, this practical book shows you exactly what to do to get the most out of Tumblr. Set up your account, choose a theme, post from your computer or phone, see how to reblog content, and befor

  18. Macs for dummies

    Baig, Edward C


    Get the most out of your Mac with this comprehensive guide Macs For Dummies, 13th Edition is the ultimate guide to your Mac, fully updated to include information about the latest updates. The book walks you through troubleshooting, syncing mobile devices, integrating Windows, and more, so you can take advantage of everything Macs have to offer. Whether you're a new user, a recent convert, or you just want to get the most out of your Mac, this book puts all the information you need in one place. Discover what makes Macs superior computing machines. Learn the basics, from mastering the Dock and

  19. Hudl for dummies

    Hattersley, Rosemary


    The essential beginner's guide to the UK's most popular new tablet Hudl For Dummies is the indispensible guide to Tesco's highly successful Android tablet. With hands-on instruction tailored to the entry-level user, this book provides expert guidance in clear, concise language to help you get the most out of this great new device. Seasoned technology author Rosie Hattersley walks you through each step, from opening the box to setting up e-mail, accessing Blinkbox, shopping online and more. Even if you're a newcomer to tablet technology, this book will have you up and running in a flash! By uti

  20. Ajax for dummies

    Holzner, Steve


    Ajax is short for "Asynchronous JavaScript+CSS+DOM+XMLHttpRequest." Even if you weren't intimidated before, that tidbit is probably enough to make you reach for the Excedrin. Just reach for Ajax For Dummies instead. With screen shots, actual code and explanations, and live Web sites where you can see Ajax applications doing their thing, it will have you using Ajax to create Web applications that look an act like desktop applications in no time. With Ajax, you can speed up and clean up your Web applications. Shoppers at your online store can fill their carts without waiting for multiple page re

  1. Data science for dummies

    Pierson, Lillian


    Discover how data science can help you gain in-depth insight into your business - the easy way! Jobs in data science abound, but few people have the data science skills needed to fill these increasingly important roles in organizations. Data Science For Dummies is the perfect starting point for IT professionals and students interested in making sense of their organization's massive data sets and applying their findings to real-world business scenarios. From uncovering rich data sources to managing large amounts of data within hardware and software limitations, ensuring consistency in report

  2. SQL for dummies

    Taylor, Allen G


    Uncover the secrets of SQL and start building better relational databases today!This fun and friendly guide will help you demystify database management systems so you can create more powerful databases and access information with ease. Updated for the latest SQL functionality, SQL For Dummies, 8th Edition covers the core SQL language and shows you how to use SQL to structure a DBMS, implement a database design, secure your data, and retrieve information when you need it. Includes new enhancements of SQL:2011, including temporal data functionality which a

  3. Electronics for dummies



    Explore the basic concepts of electronics, build your electronics workbench, and begin creating fun electronics projects right away! Electronics For Dummies, 3rd Edition is your guide to the world of electronics. Spanning circuitry, wiring, robotics, transmitters, amplifiers, and more, this book demystifies electricity basics and beyond. The third edition offers new content revised to reflect the latest advancements in the electronics field, and it offers full color project examples to spark your creativity and inspire you to put your new skills to use! Packed with projects that can be comple

  4. Geometry essentials for dummies

    Ryan, Mark


    Just the critical concepts you need to score high in geometry This practical, friendly guide focuses on critical concepts taught in a typical geometry course, from the properties of triangles, parallelograms, circles, and cylinders, to the skills and strategies you need to write geometry proofs. Geometry Essentials For Dummies is perfect for cramming or doing homework, or as a reference for parents helping kids study for exams. Get down to the basics - get a handle on the basics of geometry, from lines, segments, and angles, to vertices, altitudes, and diagonals Conque

  5. C++ for dummies

    Davis, Stephen Randy


    Enter the world of computer programming with this step-by-step guide to the C++ language! C++ is a great introduction to object-oriented programming, and this friendly guide covers everything you need to know and nothing you don't. You'll write your first program by the end of Chapter 1. C++ For Dummies, 6th Edition, helps you understand C++ programming from the ground up. It's full of examples to show you how things work, and it even explains "why", so you understand how the pieces fit together. And the bonus CD includes a special code editor, an update GNU compiler, and all source code from

  6. SPSS for Dummies

    Griffith, Arthur


    The fun and friendly guide to the world's leading statistical software. Predictive Analysis Software (PASW), formerly SPSS software, is the leading statistical software used by commerical, government, and academic organizations around the world to solve business and research problems. It allows you to quickly and easily discover new insights from data, test hypotheses, and build powerful predictive models. PASW Statistics For Dummies covers everything you need to know to get up and running with this efficient and practical software. *: *; PASW Statistics is the leading statistical software use

  7. Coding for dummies

    Abraham, Nikhil


    Hands-on exercises help you learn to code like a pro No coding experience is required for Coding For Dummies,your one-stop guide to building a foundation of knowledge inwriting computer code for web, application, and softwaredevelopment. It doesn't matter if you've dabbled in coding or neverwritten a line of code, this book guides you through the basics.Using foundational web development languages like HTML, CSS, andJavaScript, it explains in plain English how coding works and whyit's needed. Online exercises developed by Codecademy, a leading online codetraining site, help hone coding skill

  8. Business Plans For Dummies

    Tiffany, Paul; Barrow, Colin


    A full updated and extended second edition of an established UK bestseller Business Plans For Dummies 2nd Edition features new and updated information on formulating a solid business plan to build a secure business - even in an economic downturn. Complete with a brand new business plan template to get you started this expert guide offers fresh advice on reading the competitive marketplace and assessing your business in the current economic climate. It walks you step-by-step through every aspect of planning achievable business goals and diversification strategies, identifying trends, exploring

  9. Semantic web for dummies

    Pollock, Jeffrey T


    Semantic Web technology is already changing how we interact with data on the Web. By connecting random information on the Internet in new ways, Web 3.0, as it is sometimes called, represents an exciting online evolution. Whether you're a consumer doing research online, a business owner who wants to offer your customers the most useful Web site, or an IT manager eager to understand Semantic Web solutions, Semantic Web For Dummies is the place to start! It will help you:Know how the typical Internet user will recognize the effects of the Semantic WebExplore all the benefits the data Web offers t

  10. SAS for dummies

    McDaniel, Stephen


    The fun and easy way to learn to use this leading business intelligence tool Written by an author team who is directly involved with SAS, this easy-to-follow guide is fully updated for the latest release of SAS and covers just what you need to put this popular software to work in your business. SAS allows any business or enterprise to improve data delivery, analysis, reporting, movement across a company, data mining, forecasting, statistical analysis, and more. SAS For Dummies, 2nd Edition  gives you the necessary background on what SAS can do for you and explains how to use the Enterprise Gui

  11. Access 2010 for dummies

    Ulrich Fuller, Laurie


    A friendly, step-by-step guide to the Microsoft Office database application Access may be the least understood and most challenging application in the Microsoft Office suite. This guide is designed to help anyone who lacks experience in creating and managing a database learn to use Access 2010 quickly and easily. In the classic For Dummies tradition, the book provides an education in Access, the interface, and the architecture of a database. It explains the process of building a database, linking information, sharing data, generating reports, and much more.As the Micr

  12. Perl for dummies

    Hoffman, Paul


    In the days before personal computers, BASIC was the easy programming language to learn, and serious programmers learned FORTRAN or COBOL to do "real work." Today, many people have discovered that Perl is both a great beginning programming language and one that enables them to write powerful programs with little effort. If you're interested in discovering how to program (or how others program), Perl For Dummies, 4th Edition, is for you. If you already know something about programming (but not about Perl), this book is also for you. If you're already an expert programmer, you're still w

  13. English Grammar For Dummies

    Ward, Lesley J


    If you're confused by commas, perplexed by pronouns, and plain terrified by tenses, English Grammar For Dummies will put your fears to rest. Packed with expert guidance, it covers everything from sentence basics to rules even your English teacher didn't know - if you want to brush up on your grammar, this is the only guide you'll ever need. Discover how to: avoid common grammatical errors; get to grips with apostrophes; structure sentences correctly; use verbs and find the right tense; and decide when to use slang or formal English.  

  14. Spotify For Dummies

    Gilmour, Kim


    The ultimate beginner guide to the groundbreaking music service, Spotify! Spotify is a free online streaming music platform that allows users to listen to songs on demand over the Internet--without having to buy or own the actual tracks. This fun and friendly guide walks you through how best to use this sweet-sounding service. Covering everything from using Spotify on selected mobile phones to creating and sharing your own playlists, Spotify For Dummies has it all. Experienced author Kim Gilmour details the ins and outs of this revolutionary music, from installing and setup to discovering new

  15. CSS3 for dummies

    Mueller, John Paul


    Get the most out of the new features in CSS3 Cascading Style Sheets (CSS3) boasts many new features that designers love. Things like better mobility, cleaner code, less maintenance, and basic interactivity without JavaScript are just a few. Get thoroughly up to speed on CSS3 with CSS3 For Dummies. Whether you're a web developer or designer with a lot or very little experience in HTML and CSS, or just want assistance applying it to multiple browser and mobile apps, this book delivers. Explore in depth how CSS3 effects and transforms work and how to use them for animation and interactivity. E

  16. Crowdsourcing for dummies

    Grier, David Alan


    Give your business the edge with crowd-power! Crowdsourcing is an innovative way of outsourcing tasks, problems or requests to a group or community online. There are lots of ways business can use crowdsourcing to their advantage: be it crowdsourcing product ideas and development, design tasks, market research, testing, capturing or analyzing data, and even raising funds. It offers access to a wide pool of talent and ideas, and is an exciting way to engage the public with your business. Crowdsourcing For Dummies is your plain-English guide to making crowdsourcing, crowdfunding

  17. String theory for dummies

    Zimmerman Jones, Andrew


    Making Everything Easier!. String Theory for Dummies. Learn:. The basic concepts of this controversial theory;. How string theory builds on physics concepts;. The different viewpoints in the field;. String theory's physical implications. Andrew Zimmerman Jones. Physics Guide, with Daniel Robbins, PhD in Physics. Your plain-English guide to this complex scientific theory. String theory is one of the most complicated sciences being explored today. Not to worry though! This informative guide clearly explains the basics of this hot topic, discusses the theory's hypotheses and prediction

  18. Innovative presentations for dummies

    Anthony, Ray


    Be the speaker they follow with breakthrough innovative presentations Innovative Presentations For Dummies is a practical guide to engaging your audience with superior, creative, and ultra-compelling presentations. Using clear language and a concise style, this book goes way beyond PowerPoint to enable you to reimagine, reinvent, and remake your presentations. Learn how to stimulate, capture, and hold your audience in the palm of your hand with sound, sight, and touch, and get up to speed on the latest presentation design methods that make you a speaker who gets audiences committed and acting

  19. Data mining for dummies

    Brown, Meta S


    Delve into your data for the key to success Data mining is quickly becoming integral to creating value and business momentum. The ability to detect unseen patterns hidden in the numbers exhaustively generated by day-to-day operations allows savvy decision-makers to exploit every tool at their disposal in the pursuit of better business. By creating models and testing whether patterns hold up, it is possible to discover new intelligence that could change your business''s entire paradigm for a more successful outcome. Data Mining for Dummies shows you why it doesn''t take a data scientist to gain

  20. Word 2013 for dummies

    Gookin, Dan


    This bestselling guide to Microsoft Word is the first and last word on Word 2013 It's a whole new Word, so jump right into this book and learn how to make the most of it. Bestselling For Dummies author Dan Gookin puts his usual fun and friendly candor back to work to show you how to navigate the new features of Word 2013. Completely in tune with the needs of the beginning user, Gookin explains how to use Word 2013 quickly and efficiently so that you can spend more time working on your projects and less time trying to figure it all out. Walks you through the capabilit

  1. CISSP for dummies

    Miller, Lawrence C


    A fully updated guide to CISSP certification CISSP certification is the most prestigious and highly valued of the security certifications. This is the book you need to approach the exam with confidence and become CISSP certified! The CISSP Body of Knowledge underwent many changes in 2012, and this book covers them all. With a down-to-earth approach, it provides all the information covered in the exam plus numerous self-assessment tools, Quick Assessment and Prep tests to give you practice, a sample exam, and hundreds of randomly generated review questions on the Dummies Test Engine, availab

  2. Droid 4 For Dummies

    Gookin, Dan


    A handy, concise guide to the Droid 4 from bestselling author Dan Gookin As handy, productive, and trim as your new Droid 4 smartphone, this easy-in, easy-out Droid 4 guide is just what you need to get the very most out of Google's latest home-run smartphone. Bestselling For Dummies author Dan Gookin keeps you ahead of the game by thoroughly and clearly covering all the bases. Master basic phone operations, texting, portable web browsing, social networking, video chatting, and tons more, all delivered in Dan Gookin's fun, funny, fact-filled, and entertaining style. Helps you get the most out o

  3. NOOKcolor for dummies

    Sandler, Corey


    NOOKcolor For Dummies provides readers with all the information they need in order to get the most out of their NOOKcolor e-reader. Key topics covered include: Introducing the ebook and e-reader concept Navigating the technical aspects of The NOOKcolor, including touchscreen technology, wireless access, software updates Downloading and shopping for e-books Listening to music on your NOOKcolor Powering the NOOKcolor Formats Reading an e-book on an e-reader, including lighting, font adjustments, and so on Using th

  4. Optics for dummies

    Duree, Galen C


    The easy way to shed light on Optics In general terms, optics is the science of light. More specifically, optics is a branch of physics that describes the behavior and properties of light?including visible, infrared, and ultraviolet?and the interaction of light with matter. Optics For Dummies gives you an approachable introduction to optical science, methods, and applications. You'll get plain-English explanations of the nature of light and optical effects; reflection, refraction, and diffraction; color dispersion; optical devices, industrial, medical, and military applicatio

  5. Prezi for Dummies

    Diamond, Stephanie


    A one-stop resource for an exciting new Web-based, slide-free presentation tool!. People who have been seeking a flashier version of PowerPoint have found it—and it's Prezi. A Web-based, slide-free presentation tool, Prezi allows users to create and give rich, Web-based presentations complete with dynamic content, contextual layouts, and eye-catching visuals. Prezi For Dummies gets you rapidly up to speed, including how to think outside the traditional slide, create your project, insert Flash and other graphic files, and publish your presentation to a public domain. You'll also learn valuable

  6. Business statistics for dummies

    Anderson, Alan


    Score higher in your business statistics course? Easy. Business statistics is a common course for business majors and MBA candidates. It examines common data sets and the proper way to use such information when conducting research and producing informational reports such as profit and loss statements, customer satisfaction surveys, and peer comparisons. Business Statistics For Dummies tracks to a typical business statistics course offered at the undergraduate and graduate levels and provides clear, practical explanations of business statistical ideas, techniques, formulas, and calculations, w

  7. Blogging For Dummies

    Gardner, Susannah


    This proven bestseller is fully updated and better than ever! Now in its fourth edition, Blogging For Dummies is fully updated and more practical than ever for today's bloggers. Whether you're just beginning or are already a full-tilt blogging maven, you'll find the up-to-date information you need in these friendly pages. Want to integrate your blog with social media? Jump into the fast-moving world of microblogging on Twitter or Tumblr? Choose which blogging software to use? Optimize your current blog for search? This detailed book guide covers it all, and then some. Buy the book, build a bet

  8. VSTO For Dummies

    Sempf, Bill


    Learn to build custom Office applications with this new Microsoft development tool. Designed to attract both VBA (Visual Basic for Applications) and Visual Studio developers, VSTO (Visual Studio Tools for Office) is a Visual Studio add-in that makes it easy to create custom Office applications. This book shows developers step by step how to work with VSTO tools to create real-world applications for Word, Outlook, and Excel.: VSTO enables developers to easily create custom applications for Microsoft Office; In the fun and friendly For Dummies style, this book explains how to build effective use

  9. Food Blogging For Dummies

    Senyei, Kelly


    Bloggers and foodies everywhere will want this full-color book The only thing better than cooking and eating is talking about it! Combine your two loves—food and blogging—with this ultimate guide for food bloggers everywhere. Food Blogging For Dummies shows you how to join the blogosphere with your own food blog. This unique guide covers everything: how to identify your niche, design your site, find your voice, and create mouthwatering visuals of your best recipes and menus using dazzling lighting and effects. You'll learn how to optimize your blog for search, connect with social m

  10. Access 2013 for dummies

    Ulrich Fuller, Laurie


    The easy guide to Microsoft Access returns with updates on the latest version! Microsoft Access allows you to store, organize, view, analyze, and share data; the new Access 2013 release enables you to build even more powerful, custom database solutions that integrate with the web and enterprise data sources. Access 2013 For Dummies covers all the new features of the latest version of Accessand serves as an ideal reference, combining the latest Access features with the basics of building usable databases. You'll learn how to create an app from the Welcome screen, get support

  11. MYOB software for dummies

    Curtis, Veechi


    Your complete guide to MYOB® AccountRight softwareNow in its seventh edition, MYOB® Software For Dummies walks you through everything you need to know, from starting your MYOB® file from scratch and recording payments and receipts, to tracking profit and analysing sales. This new edition includes all the information you need on the new generation of MYOB® AccountRight software, including the new cloud computing features. Set up MYOB® software - understand how to make it work the first time Keep track of purchases and sales - monitor customer accounts and ensure you get pai

  12. Google+ For Dummies

    Stay, Jesse


    A new social network! Here's your user's guide to Google+ Google+ is Google's new social network and from day one it has had the social media world abuzz with excitement. Early fans claim it's easier to use than Facebook and Twitter and has a wealth of creative new features. If you want to learn how to navigate this new social neighborhood, take along Google+ For Dummies as your guide. Early Google+ adopter and social media consultant Jesse Stay shows you how to get started, create a profile, set up privacy settings, chat, post, control who sees what, and much more.Explains how to join Google+

  13. Social Entrepreneurship for Dummies

    Durieux, Mark


    Discover how to bring social responsibility to your business. In today's business world, your bottom line isn't measured by your company's financial performance alone. Social Entrepreneurship For Dummies shows you how to implement social responsibility to your business plan in order to increase your bottom line. This book helps any social entrepreneur gain the necessary skills needed to change the system and spread the solution, while providing explanations of the most successful business tools being used today.: A complete reference on the ideas and processes associated with social entreprene

  14. Calculus II For Dummies

    Zegarelli, Mark


    An easy-to-understand primer on advanced calculus topics Calculus II is a prerequisite for many popular college majors, including pre-med, engineering, and physics. Calculus II For Dummies offers expert instruction, advice, and tips to help second semester calculus students get a handle on the subject and ace their exams. It covers intermediate calculus topics in plain English, featuring in-depth coverage of integration, including substitution, integration techniques and when to use them, approximate integration, and improper integrals. This hands-on guide also covers sequences and series, wit

  15. UX for dummies

    Nichols, Kevin


    Get up to speed quickly on the latest in user experience strategy and design UX For Dummies is a hands-on guide to developing and implementing user experience strategy. Written by globally-recognized UX consultants, this essential resource provides expert insight and guidance on using the tools and techniques that create a great user experience, along with practical advice on implementing a UX strategy that aligns with your organisation's business goals and philosophy. You'll learn how to integrate web design, user research, business planning and data analysis to focus your company's web prese

  16. Leadership For Dummies

    Cole, Kris


    Created especially for the Australian customer! Improve your leadership skills and bring out the best in the people you lead People may join organisations, but they stay because of good leaders. Find out how inspiring and bringing out the best in the people you lead helps you fulfil your organisation's visions and key priorities. Leadership For Dummies, Australian and New Zealand Edition, quickly gets you up to speed on the latest leadership theories, providing practical strategies and surefire techniques to ensure you and your followers are working in the same direction. Discover how to: D

  17. Calculus for dummies

    Ryan, Mark


    Slay the calculus monster with this user-friendly guide Calculus For Dummies, 2nd Edition makes calculus manageable-even if you're one of the many students who sweat at the thought of it. By breaking down differentiation and integration into digestible concepts, this guide helps you build a stronger foundation with a solid understanding of the big ideas at work. This user-friendly math book leads you step-by-step through each concept, operation, and solution, explaining the ""how"" and ""why"" in plain English instead of math-speak. Through relevant instruction and practical examples, you'll s

  18. NOOK for dummies

    Sandler, Corey


    NOOK For Dummies provides readers with all the information they need in order to get the most out of their NOOK e-reader. Key topics covered include: Introducing the ebook and e-reader concept Navigating the technical aspects of The NOOK including touchscreen technology, wireless access, software updates Downloading and shopping for e-books Listening to music on your NOOK Powering the NOOK Formats Reading an e-book on an e-reader, including lighting, font adjustments, and so on Using the Android-based applicatio

  19. Swift for dummies

    Feiler, Jesse


    Get up and running with Swift-swiftly Brimming with expert advice and easy-to-follow instructions,Swift For Dummies shows new and existing programmers how toquickly port existing Objective-C applications into Swift and getinto the swing of the new language like a pro. Designed from theground up to be a simpler programming language, it's never beeneasier to get started creating apps for the iPhone or iPad, orapplications for Mac OS X. Inside the book, you'll find out how to set up Xcode for a newSwift application, use operators, objects, and data types, andcontrol program flow with conditiona

  20. Office 2013 for dummies

    Wang, Wallace


    Office 2013 For Dummies is the key to your brand new Office! Packed with straightforward, friendly instruction, this update to one of the bestselling Office books of all time gets you thoroughly up to speed and helps you learn how to take full advantage of the new features in Office 2013. After coverage of the fundamentals, you'll discover how to spice up your Word documents, edit Excel spreadsheets and create formulas, add pizazz to your PowerPoint presentation, and much more.Helps you harness the power of all five Office 2013 applications: Word, Excel, PowerPoint,

  1. French essentials for dummies

    Lawless, Laura K


    Just the core concepts you need to write and speak French correctly If you have some knowledge of French and want to polish your skills, French Essentials For Dummies focuses on just the core concepts you need to communicate effectively. From conjugating verbs to understanding tenses, this easy-to-follow guide lets you skip the suffering and score high at exam time. French 101 - get the lowdown on the basics, from expressing dates and times to identifying parts of speech Gender matters - see how a noun's gender determines the articles, adjectives, and pronouns y

  2. Excel 2003 for dummies

    Harvey, Greg


    Every time you turn around, you run into Excel. It's on yourPC at work. It's on your PC at home. You get Excel files fromyour boss. Wouldn't you like to understand this powerfulMicrosoft Office spreadsheet program, once and for all? Now, youcan crunch financial data, add sparkle to presentations, convertstatic lists of numbers into impressive charts, and discover whatall the shouting's about regarding databases, formulas, andcells. You may even decide that getting organized with a goodspreadsheet is downright useful and fun! Flip open Excel 2003 For Dummies, and you'llquickly start getting th

  3. Surface for dummies

    Rathbone, Andy


    Make Microsoft's Surface work-and play-just the way you want it to Microsoft's Surface tablet has the features and personality you're looking for, with a robust environment for business computing that doesn't skimp on fun. Surface for Dummies, 2nd Edition explains how Windows 8.1 Pro and Windows RT differ, and helps you decide which Surface model is best for you. Step by step, this book walks you through both the hardware and software features of the Surface, including the touch cover and type cover, Windows RT and Windows 8.1 Pro operating systems, and the coveted Office Home & Student 2013 s

  4. Nexus One For Dummies

    Gookin, Dan


    Exploit the full power of the revolutionary Google Nexus One superphone. Nexus One is Google's answer to Apple's iPhone and RIM's BlackBerry. Covering a range of how-to topics, from the most useful Nexus One features and tricks of the core applications, to techniques to get the most out of the device, Nexus One For Dummies is the practical user's guide to the Google Nexus One smartphone.: Uses full-color to showcase all the features of the Nexus One, approaching each from the point of view of the user who is new to the technology or discouraged with the scant documentation and online support;

  5. Android phones for dummies

    Gookin, Dan


    A colorful guide to make your Android phone do your bidding The popularity of Android phones is simply exploding, so it's a perfect time for popular For Dummies author Dan Gookin to update his bestselling guide to all things Android phones. From setup and configuration to taking advantage of the latest amazing Android features, this practical resource is designed to make new Android users comfortable and to help veterans get the most out of their Android phone. Covering features that are common to the most popular Android phones, this book walks you through the basics of making calls, using

  6. Beginning programming for dummies

    Wang, Wallace


    Do you think the programmers who work at your office are magical wizards who hold special powers that manipulate your computer? Believe it or not, anyone can learn how to write programs, and it doesn't take a higher math and science education to start. Beginning Programming for Dummies shows you how computer programming works without all the technical details or hard programming language. It explores the common parts of every computer programming language and how to write for multiple platforms like Windows, Mac OS X, or Linux. This easily accessible guide provides you with the tools

  7. Statistics For Dummies

    Rumsey, Deborah


    The fun and easy way to get down to business with statistics Stymied by statistics? No fear ? this friendly guide offers clear, practical explanations of statistical ideas, techniques, formulas, and calculations, with lots of examples that show you how these concepts apply to your everyday life. Statistics For Dummies shows you how to interpret and critique graphs and charts, determine the odds with probability, guesstimate with confidence using confidence intervals, set up and carry out a hypothesis test, compute statistical formulas, and more.Tracks to a typical first semester statistics cou

  8. Solder dross removal apparatus

    Webb, Winston S. (Inventor)


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

  9. Differential equations for dummies

    Holzner, Steven


    The fun and easy way to understand and solve complex equations Many of the fundamental laws of physics, chemistry, biology, and economics can be formulated as differential equations. This plain-English guide explores the many applications of this mathematical tool and shows how differential equations can help us understand the world around us. Differential Equations For Dummies is the perfect companion for a college differential equations course and is an ideal supplemental resource for other calculus classes as well as science and engineering courses. It offers step-by-step techniques, practical tips, numerous exercises, and clear, concise examples to help readers improve their differential equation-solving skills and boost their test scores.

  10. Technical Math For Dummies

    Schoenborn, Barry


    Technical Math For Dummies is your one-stop, hands-on guide to acing the math courses you’ll encounter as you work toward getting your degree, certifacation, or�license in the skilled trades. You’ll get easy-to-follow, plain-English guidance on mathematical formulas and methods that professionals use every day in the automotive, health, construction, licensed trades, maintenance, and other trades. You’ll learn how to apply concepts of algebra, geometry, and trigonometry and their formulas related to occupational areas of study. Plus, you’ll find out how to perform basic arithmetic

  11. Apple Watch for dummies

    Saltzman, Marc


    Your all-encompassing guide to the Apple Watch Are you an Apple Watch enthusiast and want to master all of its features to impress friends and intimidate enemies? Or perhaps you're a less-than-tech-savvy newcomer to the ""wearable"" craze and want to get the most out of it? In Apple Watch For Dummies, you'll discover how this incredible device does way more than simply tell time. Through hands-on, easy-to-follow instruction, you'll find out how to send and receive text messages and emails, use Siri, find movie times, access your favorite apps and get directions]. Plus, you'll get a handle on

  12. Flip Video for Dummies

    Hutsko, Joe


    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

  13. Blender For Dummies

    van Gumster, Jason


    The exciting new book on the exciting new Blender 2.5! If you want to design 3D animation, here's your chance to jump in with both feet, free software, and a friendly guide at your side! Blender For Dummies, 2nd Edition is the perfect introduction to the popular, open-source, Blender 3D animation software, specifically the revolutionary new Blender 2.5. Find out what all the buzz is about with this easy-access guide. Even if you?re just beginning, you'll learn all the Blender 2.5 ropes, get the latest tips, and soon start creating 3D animation that dazzles.Walks you through what you need to kn

  14. Business math for dummies

    Sterling, Mary Jane


    Now, it is easier than ever before to understand complex mathematical concepts and formulas and how they relate to real-world business situations. All you have to do it apply the handy information you will find in Business Math For Dummies. Featuring practical practice problems to help you expand your skills, this book covers topics like using percents to calculate increases and decreases, applying basic algebra to solve proportions, and working with basic statistics to analyze raw data. Find solutions for finance and payroll applications, including reading financial statements, calculating wages and commissions, and strategic salary planning. Navigate fractions, decimals, and percents in business and real estate transactions, and take fancy math skills to work. You'll be able to read graphs and tables and apply statistics and data analysis. You'll discover ways you can use math in finance and payroll investments, banking and payroll, goods and services, and business facilities and operations. You'll learn ho...

  15. French For Dummies

    Erotopoulos; Williams, Michelle M; Wenzel, Dominique


    The fast, informal way to learn to speak French French is known as perhaps the most beautiful of all languages. Listen to someone speak French-sure, you don't have a clue what they're saying, but aren't you enraptured by the sound of it? French is a beautiful language but quite difficult to learn. Whether you need to learn the language for a French class, or you travel overseas for business or leisure, this revised edition of French for Dummies can help. Written in an easy-to-follow format, it gives you just what you need for basic communication in FrenchExpanded coverage of necessary grammar,

  16. Quantum physics workbook for dummies

    Holzner, Steven


    Hands-on practice in solving quantum physics problems Quantum Physics is the study of the behavior of matter and energy at the molecular, atomic, nuclear, and even smaller microscopic levels. Like the other titles in our For Dummies Workbook series, Quantum Physics Workbook For Dummies allows you to hone your skills at solving the difficult and often confusing equations you encounter in this subject. Explains equations in easy-to-understand terms Harmonic Oscillator Operations, Angular Momentum, Spin, Scattering Theory Using a proven practice-and-review approach, Quantum Physics Workbook For Dummies is all you need to get up to speed in problem solving!

  17. Low temperature aluminum soldering analysis

    Peterkort, W.G.


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

  18. SAS for dummies

    McDaniel, Stephen


    The fun and easy way to learn to use this leading business intelligence tool Written by an author team who is directly involved with SAS, this easy-to-follow guide is fully updated for the latest release of SAS and covers just what you need to put this popular software to work in your business. SAS allows any business or enterprise to improve data delivery, analysis, reporting, movement across a company, data mining, forecasting, statistical analysis, and more. SAS For Dummies, 2nd Edition  gives you the necessary background on what SAS can do for you and explains how to use the Enterprise Guide. SAS provides statistical and data analysis tools to help you deal with all kinds of data: operational, financial, performance, and more Places special emphasis on Enterprise Guide and other analytical tools, covering all commonly used features Covers all commonly used features and shows you the practical applications you can put to work in your business Explores how to get various types of data into the software and...

  19. Effect of interface microstructure on the mechanical properties of Pb-free hybrid microcircuit solder joints

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


    Although Sn-Pb eutectic alloy is widely used as a joining material in the electronics industry, it has well documented environmental and toxicity issues. Sandia National Laboratories is developing alternative solder materials to replace traditional Pb-containing alloys. The alloys are based on the Sn-Ag, Sn-Ag-Bi and Sn-Ag-Bi-Au systems. Prototype hybrid microcircuit (HMC) test vehicles have been developed to evaluate these Pb-free solders, using Au-Pt-Pd thick film metallization. Populated test vehicles with surface mount devices have been designed and fabricated to evaluate the reliability of surface mount solder joints. The test components consist of a variety of dummy chip capacitors and leadless ceramic chip carriers (LCCC`s). Intermetallic compound (IMC) layer reaction products that form at the solder/substrate interface have been characterized and their respective growth kinetics quantified. Thicker IMC layers pose a potential reliability problem with solder joint integrity. Since the IMC layer is brittle, the likelihood of mechanical failure of a joint in service is increased. The effect of microstructure and the response of these different materials to wetting, aging and mechanical testing was also investigated. Solid-state reaction data for intermetallic formation and mechanical properties of the solder joints are reported.

  20. Mechanical properties of Pb-free solder alloys on thick film hybrid microcircuits

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


    The technology drivers of the electronics industry continue to be systems miniaturization and reliability, in addition to addressing a variety of important environmental issues. Although the Sn-Pb eutectic alloy is widely used as a joining material in the electronics industry, it has drawn environmental concern due to its Pb content. The solder acts both as an electrical and mechanical connection within the different packaging levels in an electronic device. New Pb-free solders are being developed at Sandia National Laboratories. The alloys are based on the Sn-Ag alloy, having Bi and Au additions. Prototype hybrid microcircuit (HMC) test vehicles have been assembled to evaluate Pb-free solders for Au-Pt-Pd thick film soldering. The test components consist of a variety of dummy chip capacitors and leadless ceramic chip carriers (LCCC`s). The mechanical properties of the joints were evaluated. The reflow profiles and the solid state intermetallic formation reaction will also be presented. Improved solder joint manufacturability and increased fatigue resistance solder alloys are the goals of these materials.

  1. Microsoft Expression Web for dummies

    Hefferman, Linda


    Expression Web is Microsoft's newest tool for creating and maintaining dynamic Web sites. This FrontPage replacement offers all the simple ""what-you-see-is-what-you-get"" tools for creating a Web site along with some pumped up new features for working with Cascading Style Sheets and other design options. Microsoft Expression Web For Dummies arrives in time for early adopters to get a feel for how to build an attractive Web site. Author Linda Hefferman teams up with longtime FrontPage For Dummies author Asha Dornfest to show the easy way for first-time Web designers, FrontPage ve

  2. Excel 2010 Workbook for Dummies

    Harvey, Greg


    Reinforce your understanding of Excel with these Workbook exercises. Boost your knowledge of important Excel tasks by putting your skills to work in real-world situations. The For Dummies Workbook format provides more than 100 exercises that help you create actual results with Excel so you can gain proficiency. Perfect for students, people learning Excel on their own, and financial professionals who must plan and execute complex projects in Excel, Excel 2010 Workbook For Dummies helps you discover all the ways this program can work for you.: Excel is the world's most popular number-crunching p

  3. Excel data analysis for dummies

    Nelson, Stephen L


    Harness the power of Excel to discover what your numbers are hiding Excel Data Analysis For Dummies, 2nd Edition is the ultimate guide to getting the most out of your data. Veteran Dummies author Stephen L. Nelson guides you through the basic and not-so-basic features of Excel to help you discover the gems hidden in your rough data. From input, to analysis, to visualization, the book walks you through the steps that lead to superior data analysis. Excel is the number-one spreadsheet application, with ever-expanding capabilities. If you're only using it to balance the books, you're missing out

  4. Signals and systems for dummies

    Wickert, Mark


    Getting mixed signals in your signals and systems course? The concepts covered in a typical signals and systems course are often considered by engineering students to be some of the most difficult to master. Thankfully, Signals & Systems For Dummies is your intuitive guide to this tricky course, walking you step-by-step through some of the more complex theories and mathematical formulas in a way that is easy to understand. From Laplace Transforms to Fourier Analyses, Signals & Systems For Dummies explains in plain English the difficult concepts that can trip you up

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

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


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

  6. The Japanese Copula: A Dummy?

    Wenck, G.


    Discussion of whether the Japanese copula can adequately be described as a dummy, i.e., as an element which although existing in the surface structure can be dispensed with in the deep structure of a sentence; based on a paper read at the 1970 meeting of the Societas Linguistica Europaea, Prague, Czechoslovakia. (RS)

  7. The Japanese Copula: A Dummy?

    Wenck, G.


    Discussion of whether the Japanese copula can adequately be described as a dummy, i.e., as an element which although existing in the surface structure can be dispensed with in the deep structure of a sentence; based on a paper read at the 1970 meeting of the Societas Linguistica Europaea, Prague, Czechoslovakia. (RS)

  8. Soldering of Nanotubes onto Microelectrodes

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


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

  9. Capillary flow solder wettability test

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


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

  10. iMac for dummies

    Chambers, Mark L


    Do it all with your iMac and this bestselling For Dummies guide! You're still a little giddy from finally scoring your new iMac, and you can't wait to get started. Even if you're already in love with your iMac, it helps to have a little guidance to really get the most out of this ultimate all-in-one computer. This updated edition of iMac For Dummies is the ideal way to learn the iMac fundamentals from setting up and personalizing your machine to importing files, making FaceTime video calls, surfing the web, using your favorite programs and apps, and everything in between. Trusted Mac guru Mark

  11. Macs For Seniors For Dummies

    Chambers, Mark L


    You're never too old to fall in love—with your Mac! You took a while, but you are now the proud owner of your first Mac computer. Macs For Seniors For Dummies is just for you. This friendly, accessible guide walks you through choosing a Mac and learning how to use it. You'll find yourself falling head over heels for your Mac in no time. Macs For Seniors For Dummies introduces you to all the basics that you need to know: turning the Mac on and getting connected; using the keyboard and mouse; working with files and folders; navigate around the Mac desktop and OS X Lion; setting up an Inter

  12. Macs for seniors for dummies

    Chambers, Mark L


    Over 50 and thinking about getting your first computer? A user-friendly Mac is a great choice, and Macs For Seniors For Dummies walks you through choosing one and learning to use it. You won't even need your grandchildren to help! Macs For Seniors For Dummies introduces you to all the basic things you may not have encountered before-how to use the keyboard and mouse, work with files and folders, navigate around the Mac OS X desktop, set up an Internet connection, and much more. You'll learn to:Choose the Mac that's right for you, set it up, run programs and manage files, and hook up a printerU

  13. Android app development for dummies

    Burton, Michael


    The updated edition of the bestselling guide to Android app development If you have ambitions to build an Android app, this hands-on guide gives you everything you need to dig into the development process and turn your great idea into a reality! In this new edition of Android App Development For Dummies, you'll find easy-to-follow access to the latest programming techniques that take advantage of the new features of the Android operating system. Plus, two programs are provided: a simple program to get you started and an intermediate program that uses more advanced aspects of the Android plat

  14. Kindle Fire HDX for dummies

    Muir, Nancy C


    Spark your interest in Kindle Fire HDX and start burning through books, movies, music, and more with this bestselling guide! The Kindle Fire HDX is Amazon's premiere tablet. With its new, more powerful Android operating system, this latest version has some exciting bells and whistles along with the features that have made the Fire a tablet fan favorite: access to the amazing Amazon Appstore, online music storage, a large music and video store, a huge e-book library, and easy one-step ordering from Amazon. This full-color, For Dummies guide shows you how to take advantage of all the Kindle Fi

  15. Algebra I Essentials For Dummies

    Sterling, Mary Jane


    With its use of multiple variables, functions, and formulas algebra can be confusing and overwhelming to learn and easy to forget. Perfect for students who need to review or reference critical concepts, Algebra I Essentials For Dummies provides content focused on key topics only, with discrete explanations of critical concepts taught in a typical Algebra I course, from functions and FOILs to quadratic and linear equations. This guide is also a perfect reference for parents who need to review critical algebra concepts as they help students with homework assignments, as well as for adult learner

  16. Business Plans Kit For Dummies

    Barrow, Colin


    An interactive guide to every element of the business planning processAre you an entrepreneur who wants to make it big? A manager grappling with logistics? A small business owner trying to map out a future in shaky economic times? Then look no further! Business Plans Kit For Dummies is a nuts-and-bolts guide to evaluating and invigorating your commercial strategy, no matter how big or small your business.Lay the foundations - identify your long-term goals and brainstorm your business options Develop the skills - sketch out a working model, size up competitors and fire up your marketing machine

  17. PRINCE2 For Dummies 2009

    Graham, Nick


    Whatever your project - no matter how big or small - PRINCE2 For Dummies, 2009 Edition is the perfect guide to using this project management method to help ensure its success. Fully updated with the 2009 practice guidelines, this book will take you through every step of a project - from planning and establishing roles to closing and reviewing - offering practical and easy-to-understand advice on using PRINCE2. It also shows how to use the method when approaching the key concerns of project management, including setting up effective controls, managing project risk, managing quality and controll

  18. Pre-Calculus For Dummies

    Kuang, Yang


    The fun and easy way to learn pre-calculus Getting ready for calculus but still feel a bit confused? Have no fear. Pre-Calculus For Dummies is an un-intimidating, hands-on guide that walks you through all the essential topics, from absolute value and quadratic equations to logarithms and exponential functions to trig identities and matrix operations. With this guide's help you'll quickly and painlessly get a handle on all of the concepts - not just the number crunching - and understand how to perform all pre-calc tasks, from graphing to tackling proofs. You'll also get a new appreciation for

  19. Photoshop Elements 10 For Dummies

    Obermeier, Barbara


    Perfect your photos and images with this "focused" guide to the latest version of Photoshop Elements For most of us, the professional-level Photoshop is overkill for our needs. Amateur photographers and photo enthusiasts turn to Photoshop Elements for a powerful but simpler way to edit and retouch their snapshots. Photoshop Elements 10 For Dummies, fully updated and revised for the latest release of this software product, helps you navigate Elements to create, edit, fix, share, and organize the high-quality images you desire. Full color pages bring the techniques to life and make taking great

  20. The Leadership Brain for Dummies

    Sprenger, Marilee B


    Discover how scientific knowledge of the brain can make you a better leader. Based upon the latest breakthroughs in neuroscience and advances in brain-based education, Leadership Brain For Dummies gives you the edge to influence, lead, and transform any team or organization. Drawing concrete connections between the growing scientific knowledge of the brain and leadership, this book gives you the skills to assess your strengths and weaknesses as a leader, adopt a style of leadership that suits your characteristics, determine the learning styles of individual employees, and conduct training sess

  1. Algebra II workbook for dummies

    Sterling, Mary Jane


    To succeed in Algebra II, start practicing now Algebra II builds on your Algebra I skills to prepare you for trigonometry, calculus, and a of myriad STEM topics. Working through practice problems helps students better ingest and retain lesson content, creating a solid foundation to build on for future success. Algebra II Workbook For Dummies, 2nd Edition helps you learn Algebra II by doing Algebra II. Author and math professor Mary Jane Sterling walks you through the entire course, showing you how to approach and solve the problems you encounter in class. You'll begin by refreshing your Algebr

  2. Data driven marketing for dummies

    Semmelroth, David


    Embrace data and use it to sell and market your products Data is everywhere and it keeps growing and accumulating. Companies need to embrace big data and make it work harder to help them sell and market their products. Successful data analysis can help marketing professionals spot sales trends, develop smarter marketing campaigns, and accurately predict customer loyalty. Data Driven Marketing For Dummies helps companies use all the data at their disposal to make current customers more satisfied, reach new customers, and sell to their most important customer segments more efficiently. Identifyi

  3. FarmVille For Dummies

    Morales, Angela


    The only how-to, full-color book available on the game sensation FarmVille. With more than 80 million active players since the game?s release in 2009, there seems no end to the growing popularity of FarmVille. Whether accessed through the Facebook application or from the game?s Web site, this application is a worldwide phenomenon. Yet, there has been no beginner guide that offers an introduction to newcomers and updates to experienced players?until now. FarmVille For Dummies is aimed at getting novices acquainted with FarmVille rules and regulations, while more savvy players can sharpen their

  4. Network Access Control For Dummies

    Kelley, Jay; Wessels, Denzil


    Network access control (NAC) is how you manage network security when your employees, partners, and guests need to access your network using laptops and mobile devices. Network Access Control For Dummies is where you learn how NAC works, how to implement a program, and how to take real-world challenges in stride. You'll learn how to deploy and maintain NAC in your environment, identify and apply NAC standards, and extend NAC for greater network security. Along the way you'll become familiar with what NAC is (and what it isn't) as well as the key business drivers for deploying NAC.Learn the step

  5. English Grammar Workbook For Dummies

    Woods, Geraldine


    Get some good grammar practice-and start speaking and writing well. Good grammar is important, whether you want to advance your career, boost your GPA, or increase your SAT or ACT score. Practice is the key to improving your grammar skills, and that's what this workbook is all about. Honing speaking and writing skills through continued practice translates into everyday situations, such as writing papers, giving presentations, and communicating effectively in the workplace or classroom. In English Grammar Workbook For Dummies you'll find hundreds of fun problems to help build your grammar muscl

  6. Oracle 12c for dummies

    Ruel, Chris


    Demystifying the power of the Oracle 12c database The Oracle database is the industry-leading relational database management system (RDMS) used from small companies to the world's largest enterprises alike for their most critical business and analytical processing. Oracle 12c includes industry leading enhancements to enable cloud computing and empowers users to manage both Big Data and traditional data structures faster and cheaper than ever before. Oracle 12c For Dummies is the perfect guide for a novice database administrator or an Oracle DBA who is new to Oracle 12c. The book covers what

  7. Protecting yourself online for dummies

    Muir, Nancy C


    Protect your privacy and use the internet safely! Don't let news about internet risks deter you from taking full advantage of its benefits! The web is such an amazing and useful resource for connecting with friends and family, shopping, banking, catching up on current events, and getting help in a myriad of ways. Let AARP's Protecting Yourself Online For Dummies arm you with the information you need to use the internet with confidence. You'll learn: How and why risks can occurSteps to protect yourself from identity theft, fraud, and e-mail scamsExpert tips for creating strong passwords and s

  8. Java for dummies quick reference

    Lowe, Doug


    A reference that answers your questions as you move through your coding The demand for Android programming and web apps continues to grow at an unprecedented pace and Java is the preferred language for both. Java For Dummies Quick Reference keeps you moving through your coding while you solve a problem, look up a command or syntax, or search for a programming tip. Whether you're a Java newbie or a seasoned user, this fast reference offers you quick access to solutions without requiring that you wade through pages of tutorial material. Leverages the true reference format that is organized with

  9. Dreamweaver CS6 For Dummies

    Warner, Janine


    Start creating websites that wow with the Dreamweaver CS6! Powerful yet easy to master, Dreamweaver is the dominant professional web development tool. Web design expert Janine Warner has updated her bestselling Dreamweaver For Dummies guide for the latest release of the software and walks you through the essential steps to building the website you’ve always wanted. Both beginning and intermediate web developers will get the information they need from this easy-to-follow reference to Dreamweaver CS6. Dreamweaver is the gold standard for website development software; this book covers wha

  10. 500 French verbs for dummies



    Vexed by French verbs? Fear no more! In 500 French Verbs For Dummies, beginning French language learners can find a quick reference for verbs in the basic present tenses. More advanced French speakers can utilize this book to learn more complex verb tenses and conjugations as well as advanced verbs with irregular endings. One page for each of the 500 most commonly used verbs in the French language -alphabetically arranged and numbered for easy referenceSpecial designation of the 50 most essential French verbsA summary of basic French grammar that incl

  11. Photoshop CS6 For Dummies

    Bauer, er


    The bestselling guide to the leading image-editing software, Photoshop CS6, fully updated! Want picture-perfect photos, every time? Get up to speed on the most popular professional photo-editing software on the market: Photoshop. In this new edition of Photoshop CS6 For Dummies, expert Peter Bauer shows you how to use the latest Photoshop tools to change a background, adjust brightness, improve color, or fix flaws. Richly illustrated in full color, this edition covers all the updates in the newest version of Photoshop, the gold standard for image-editing programs. Used by professional

  12. Photoshop CS5 for dummies

    Bauer, Peter


    The bestselling guide to the leading image-editing software, fully updated Previous editions of this For Dummies guide have sold more 650,000 copies. Richly illustrated in full color, this edition covers all the updates in the newest version of Photoshop, the gold standard for image-editing programs. Used by professional photographers, graphic designers, and Web designers as well as hobbyists, Photoshop has more than four million users worldwide.Photoshop is the image-editing software preferred by professional photographers and designers around the world; the latest ver

  13. English Grammar Workbook For Dummies

    O'Sullivan, Nuala


    English Grammar Workbook For Dummies, UK Edition is grammar First Aid for anyone wanting to perfect their English and develop the practical skills needed to write and speak correctly. Each chapter focuses on key grammatical principles, with easy-to-follow theory and examples as well as practice questions and explanations. From verbs, prepositions and tenses, to style, expressions and tricky word traps, this hands-on workbook is essential for both beginners looking to learn and practise the basics of English grammar, and those who want to brush up skills they already have - quickly, easily, and

  14. StumbleUpon for dummies

    Olenski, Steve


    Discover new and interesting online content based on your interests! StumbleUpon helps you discover new and interesting content on the Internet based on your specific interests. With this helpful For Dummies guide, you will learn to complete a profile that alerts StumbleUpon what topics interest you and assists in making your online perusing interesting and productive. Coverage explains how the Stumble button allows StumbleUpon to learn more about you and what type of content you like to view and it also helps that particular piece of content turn up higher in other users' searches.Gets you s

  15. Agile Project Management For Dummies

    Layton, Mark C


    Be flexible and faster with Agile project management As mobile and web technologies continue to evolve rapidly, there is added pressure to develop and implement software projects in weeks instead of months. Agile Project Management For Dummies can make that happen. This is the first book to provide a simple, step-by-step guide to Agile Project Management approaches, tools, and techniques. With the fast pace of mobile and web technology development, software project development must keep pace; Agile Project Management enables developers to complete and implement projects more quickly and this b

  16. OS X Mavericks for dummies

    LeVitus, Bob


    Coast through OS X Mavericks with help from Dr. Mac and For Dummies Ready to make friends with Mavericks? Then, Dr. Mac's your man. Author and longtime Mac guru, Bob "Dr. Mac" LeVitus shares his witty insights and helpful tips in this full-color update to his bestselling OS X guide. You'll learn the basics of working with the Dock, Launchpad, and Mission Control before moving on to setting up your e-mail, surfing with Safari, organizing your files, and customizing OS X Mavericks for all you need your Mac to do. Familiarizes you with OS X essentials like navigating the desktop, connecting to

  17. Harmonizing the European Side Impact Dummy

    Ratingen, M.R. van; Waagmeester, C.D.; Twisk, D.R.; Wismans, J.


    A major problem in side impact protection is the specification of the dummy used in the compliance tests, which is both a standardization and a technical problem. Currently, Europe and Japan use the EUROSID-1 dummy while the US.SID is used in North America. ISO initiated the WorldSID project to

  18. Soldering Formalism Theory and Applications

    Wotzasek, C


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

  19. Dummies and the sudden infant death syndrome.

    Mitchell, E A; Taylor, B J; Ford, R P; Stewart, A W; Becroft, D M; Thompson, J M; Scragg, R; Hassall, I B; Barry, D M; Allen, E M


    The association between dummy use and sudden infant death syndrome (SIDS) was investigated in 485 deaths due to SIDS in the postneonatal age group and compared with 1800 control infants. Parental interviews were completed in 87% of subjects. The prevalence of dummy use in New Zealand is low and varies within New Zealand. Dummy use in the two week period before death was less in cases of SIDS than in the last two weeks for controls (odds ratio (OR) 0.76, 95% confidence interval (CI) 0.57 to 1.02). Use of a dummy in the last sleep for cases of SIDS or in the nominated sleep for controls was significantly less in cases than controls (OR 0.44, 95% CI 0.26 to 0.73). The OR changed very little after controlling for a wide range of potential confounders. It is concluded that dummy use may protect against SIDS, but this observation needs to be repeated before dummies can be recommended for this purpose. If dummy sucking is protective then it is one of several factors that may explain the higher mortality from SIDS in New Zealand than in other countries, and may also explain in part the regional variation within New Zealand. PMID:8503676

  20. NoSQL for dummies

    Fowler, Adam


    Get up to speed on the nuances of NoSQL databases and what they mean for your organization This easy to read guide to NoSQL databases provides the type of no-nonsense overview and analysis that you need to learn, including what NoSQL is and which database is right for you. Featuring specific evaluation criteria for NoSQL databases, along with a look into the pros and cons of the most popular options, NoSQL For Dummies provides the fastest and easiest way to dive into the details of this incredible technology. You'll gain an understanding of how to use NoSQL databases for mission-critical enter

  1. jQuery For Dummies

    Beighley, Lynn


    Learn how jQuery can make your Web page or blog stand out from the crowd!. jQuery is free, open source software that allows you to extend and customize Joomla!, Drupal, AJAX, and WordPress via plug-ins. Assuming no previous programming experience, Lynn Beighley takes you through the basics of jQuery from the very start. You'll discover how the jQuery library separates itself from other JavaScript libraries through its ease of use, compactness, and friendliness if you're a beginner programmer. Written in the easy-to-understand style of the For Dummies brand, this book demonstrates how you can a

  2. iMac for dummies

    Chambers, Mark L


    The bestselling guide to the ultimate all-in-one computer—now updated and revised throughout! If you're looking for speed, performance, and power, the iMac is the ultimate all-in-one computer. From its superior performance, powerful operating system, and amazing applications, the iMac is one awesome machine, and the fun, friendly, and approachable style of iMac For Dummies is an ideal way to get started with the basics. You'll learn the fundamentals of the iMac including setting up and customizing your iMac and the software that comes with it, importing files from your old computer, send

  3. Solder joint technology materials, properties, and reliability

    Tu, King-Ning


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

  4. Wetting behavior of alternative solder alloys

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


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

  5. Solder Joint Health Monitoring Testbed

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


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

  6. Handbook of machine soldering SMT and TH

    Woodgate, Ralph W


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

  7. SEMICONDUCTOR TECHNOLOGY Dummy fill effect on CMP planarity

    Junxiong, Zhou; Lan, Chen; Wenbiao, Ruan; Zhigang, Li; Weixiang, Shen; Tianchun, Ye


    With the use of a chemical-mechanical polishing (CMP) simulator verified by testing data from a foundry, the effect of dummy fill characteristics, such as fill size, fill density and fill shape, on CMP planarity is analyzed. The results indicate that dummy density has a significant impact on oxide erosion, and copper dishing is in proportion to dummy size. We also demonstrate that cross shape dummy fill can have the best dishing performance at the same density.

  8. Java and Android application development for dummies

    Burd; Franken, Gerhard


    Two complete e-books covering Java and Android application development for one low price! This unique value-priced e-book set brings together two bestselling For Dummies books in a single e-book file. Including a comprehensive table of contents and the full text of each book, complete with cover, this e-book set gives you in-depth information on using the Java language to create powerful Android applications for mobile devices. Best of all, you'll pay less than the cost of each book purchased separately. You'll get the complete text of: Java For Dummies, 5th Edition, which shows you how

  9. AutoCAD 2010 For Dummies

    Byrnes, David


    AutoCAD is the hot computer-aided design software known for both its powerful tools and its complexity. AutoCAD 2010 for Dummies is the bestselling guide that walks you through this complicated program so you can build complex 3D technical drawings, edit like a pro, enter new dimensions, and plot with style. AutoCAD 2010 for Dummies helps you navigate the program, use the AutoCAD Design Center, create a basic layout and work with dimension, and put your drawings on the Internet. You'll soon be setting up the AutoCAD environment, using the AutoCAD Ribbon, creating annotation and dimension drawi

  10. Pre-Algebra Essentials For Dummies

    Zegarelli, Mark


    Many students worry about starting algebra. Pre-Algebra Essentials For Dummies provides an overview of critical pre-algebra concepts to help new algebra students (and their parents) take the next step without fear. Free of ramp-up material, Pre-Algebra Essentials For Dummies contains content focused on key topics only. It provides discrete explanations of critical concepts taught in a typical pre-algebra course, from fractions, decimals, and percents to scientific notation and simple variable equations. This guide is also a perfect reference for parents who need to review critical pre-algebra

  11. iPad mini for dummies

    Baig, Edward C


    Find out why the iPad mini has never been bigger This new edition of iPad mini For Dummies covers all the latest tips and tricks for getting an even bigger bang out of your iPad mini. Presented in full-color and written in the straightforward but fun language that has defined the For Dummies brand for more than twenty years, this friendly guide walks you through the multitouch interface, going online, getting connected, packing your iPad mini with apps, games, e-books, photos, music, and movies, synchronizing your data, texting with iMessage, working with Siri, importing pictures and launching

  12. Windows 8 & Office 2010 for dummies

    Rathbone, Andy


    Two complete e-books covering Windows and Office for one low price! This unique value-priced e-book set brings together two bestselling For Dummies books in a single e-book file. Including a comprehensive table of contents and the full text of each book, complete with cover, this e-book set gives you in-depth information on the leading PC productivity tools: Windows 8 and Office 2010. Best of all, you'll pay less than the cost of each book purchased separately. You'll get the complete text of: Windows 8 For Dummies, which covers The core component

  13. Linux all-in-one for dummies

    Dulaney, Emmett


    Eight minibooks in one volume cover every important aspect of Linux and everything you need to know to pass level-1 certification Linux All-in-One For Dummies explains everything you need to get up and running with the popular Linux operating system. Written in the friendly and accessible For Dummies style, the book ideal for new and intermediate Linux users, as well as anyone studying for level-1 Linux certification. The eight minibooks inside cover the basics of Linux, interacting with it, networking issues, Internet services, administration, security, scripting, and level-1 certification. C

  14. Samsung Galaxy S5 for dummies

    Hughes, Bill


    Explore Samsung's next generation Galaxy smartphone Do you want an easy-to-follow guide to everything your new Galaxy S5 smartphone can do? From the basics of texting and accessing the Internet to the most advanced features and new software apps, Samsung Galaxy S5 For Dummies makes the need for tech support obsolete. The Galaxy S5 is designed to be faster and more powerful than ever. This latest release in the market-leading line of smartphones is full of new features for you to explore with the help of Samsung Galaxy S5 For Dummies. With over 1 million apps available for the Google Android o

  15. The origins of the universe for dummies

    Pincock, Stephen


    Do you want to learn about the physical origin of the Universe, but don't have the rest of eternity to read up on it? Do you want to know what scientists know about where you and your planet came from, but without the science blinding you? 'Course you do - and who better than For Dummies to tackle the biggest, strangest and most wonderful question there is! The Origins of the Universe For Dummies covers: Early ideas about our universeModern cosmologyBig Bang theoryDark matter and gravityGalaxies and solar systemsLife on earthFi

  16. Lead free solder mechanics and reliability

    Pang, John Hock Lye


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

  17. Die Soldering in Aluminium Die Casting

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


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

  18. Using dummies for surgical skills training

    Langebæk, Rikke


    teaching methods for veterinary surgical training. At the Department of Small Animal Clinical Sciences, Faculty of Life Sciences, a number of low fidelity, stuffed toy animal dummies was developed for the Surgical Skills Lab in order to teach 4th year students the basic surgical skills. In the Surgical...... this a relatively low budget solution with a big ethical benefit....

  19. Word 2013 elearning kit for dummies

    Wempen, Faithe


    Lois Lowe is the author of several books on Microsoft Office, including Microsoft Word 2010 eLearning Kit For Dummies. She is also an online instructor who develops and teaches courses on Microsoft Office applications, computer purchase and upgrade, home office setup and emerging hardware technologies. Her courses have educated over 250,000 students for clients including Hewlett-Packard and Sony.

  20. Advances in numerical modelling of crash dummies

    Verhoeve, R.; Kant, R.; Margerie, L.


    Nowadays virtual testing and prototyping are generally accepted methods in crash safety research and design studies. Validated numerical crash dummy models are necessary tools in these methods. Computer models need to be robust, accurate and CPU efficient, where the balance between accuracy and effi

  1. No Dummies: Deafness, Baseball, and American Culture

    Edwards, R. A. R.


    This article begins by examining the historical and social factors that led to 1901 being the "deafest" year in major league baseball history with four deaf players. In particular, the author discusses the career of William Ellsworth "Dummy" Hoy, a deaf man from Ohio who became the most celebrated deaf player in history and explores the reasons…

  2. Advances in numerical modelling of crash dummies

    Verhoeve, R.; Kant, R.; Margerie, L.


    Nowadays virtual testing and prototyping are generally accepted methods in crash safety research and design studies. Validated numerical crash dummy models are necessary tools in these methods. Computer models need to be robust, accurate and CPU efficient, where the balance between accuracy and effi

  3. No Dummies: Deafness, Baseball, and American Culture

    Edwards, R. A. R.


    This article begins by examining the historical and social factors that led to 1901 being the "deafest" year in major league baseball history with four deaf players. In particular, the author discusses the career of William Ellsworth "Dummy" Hoy, a deaf man from Ohio who became the most celebrated deaf player in history and…

  4. No Dummies: Deafness, Baseball, and American Culture

    Edwards, R. A. R.


    This article begins by examining the historical and social factors that led to 1901 being the "deafest" year in major league baseball history with four deaf players. In particular, the author discusses the career of William Ellsworth "Dummy" Hoy, a deaf man from Ohio who became the most celebrated deaf player in history and…

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

    田艳红; 王春青


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



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

  7. Nano-soldering to single atomic layer

    Girit, Caglar O.; Zettl, Alexander K.


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

  8. Low cycle fatigue of lead free solder joints

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


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

  9. iPhone Application Development For Dummies

    Goldstein, Neal


    Here's the fun and easy way to learn how to create your own iPhone applications. Whether you're a professional developer or an iPhone user with a knack for technology, this plain English guide shows you how easy it can be to create your own cool iPhone and iPod touch apps. The open iPhone SDK offers a world of opportunities, and with the information in iPhone Application Development For Dummies , you can get in on the fun and profit. You don't need high-level programming skills to create iPhone apps. iPhone Application Development For Dummies walks you through the fundamentals for building a v

  10. iPhone for seniors for dummies

    Muir, Nancy C


    The fun and friendly full-color guide to finding your way around your iPhone Everywhere you look it seems like someone is using an iPhone. If you're feeling left out of the fun, don't despair. For Dummies to the rescue! Written in the accessible For Dummies style and packed with colorful illustrations, this book shows you how to use your iPhone to make and receive calls, send text messages and e-mails, read e-books, watch movies, play games, surf the web, and so much more. By the time you're through with this all-new edition of this perennial bestseller, you'll be completely comfortable down

  11. Cooling experiments using dummies covered by leaves.

    Althaus, L; Stückradt, S; Henssge, C; Bajanowski, T


    One main method to estimate the time of death is the measurement of the body temperature. The cooling of a corpse depends on a number of conditions including the surroundings. In cases where the cooling conditions differ from the defined standard, a corrective factor is used to characterise the influence of clothing, air movement, the properties of the supporting base and the humidity. Nothing is known about the significance of other circumstances, for example of a tegument by leaves or wet leaves. Therefore, the cooling of dummies which were placed on a 2-cm-thick layer of wet/dry leaves and covered by a 10-cm-thick layer of leaves was investigated. Corrective factors of 1.0 for wet leaves on the ground and of 1.3 and 1.5 for drier leaves were found. If the dummies were additionally covered, corrective factors ranged between 1.8 and 2.7.

  12. iPad & Siri for dummies

    Baig, Edward C


    Two complete e-books on using iPad and Siri for one low price! This unique value-priced e-book set brings together two bestselling For Dummies books in a single e-book file. Including a comprehensive table of contents and the full text of each book, complete with cover, this e-book set helps you get the most out of your iPad and Siri, its artificial intelligence personal assistant. Best of all, you'll pay less than the cost of each book purchased separately. You'll get the complete text of: iPad For Dummies, which helps you toSet up your iPad, browse the

  13. Belle Maudsley Lecture. Digits, dummies and malocclusions.

    Moore, M B


    When considering the aetiology of malocclusion in general, factors are often cited as having a genetic basis or an environmental basis. An individual malocclusion is likely to be a result of the variable effects of multiple environmental influences, upon an equally variable genetic predisposition. One of the most tangible 'environmental' factors is that of sucking habits involving digits or dummies. This review considers the nature of these habits, their effects on the developing dentition and methods used to combat the problem.

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


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

  15. Lead Ingestion Hazard in Hand Soldering Environments.



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

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


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

  17. Organic solderability preservation evaluation. Topical report

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


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

  18. Soldering Chiralities; 2, Non-Abelian Case

    Wotzasek, C


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

  19. Shrink-Fit Solderable Inserts Seal Hermetically

    Croucher, William C.


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

  20. Laser soldering of Sn-Ag-Cu and Sn-Zn-Bi lead-free solder pastes

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


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

  1. Mums, Dummies and "Dirty Dids": The Dummy as a Symbolic Representation of Mothering?

    Whitmarsh, Judy


    The bio medical expert literature, although contested, associates the use of dummies, soothers or pacifiers, with illness, dental malformation, impaired speech and language, and working-class mothering. This article suggests this negative perspective has filtered, via experts and the media, into public narratives of "good" mothering. Interviews…

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

    Trent, M.A.


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

  3. Integrated environmentally compatible soldering technologies. Final report

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


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

  4. SNL initiatives in electronic fluxless soldering

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

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

  5. PWB solder wettability after simulated storage

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


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

  6. PHP and MySQL for Dummies

    Valade, Janet


    Here's what Web designers need to know to create dynamic, database-driven Web sites. To be on the cutting edge, Web sites need to serve up HTML, CSS, and products specific to the needs of different customers using different browsers. An effective e-commerce site gathers information about users and provides information they need to get the desired result. PHP scripting language with a MySQL back-end database offers an effective way to design sites that meet these requirements. This full updated 4th Edition of PHP & MySQL For Dummies gets you quickly up to speed, even if your experience is limit

  7. Basic Maths Practice Problems For Dummies

    Beveridge, Colin


    Fun, friendly coaching and all the practice you need to tackle maths problems with confidence and ease In his popular Basic Maths For Dummies, professional maths tutor Colin Beveridge proved that he could turn anyone - even the most maths-phobic person - into a natural-born number cruncher. In this book he supplies more of his unique brand of maths-made- easy coaching, plus 2,000 practice problems to help you master what you learn. Whether you're prepping for a numeracy test or an employability exam, thinking of returning to school, or you'd just like to be one of those know-it-alls who says

  8. Conflict Resolution at Work for Dummies

    Scott, Vivian


    A practical workplace guide to handling conflict effectively. Managing employees and encouraging them to work together toward a common goal is an essential skill that all leaders should possess. Conflict Resolution at Work For Dummies provides the tools and advice you need to restore peace, train your colleagues to get along better with others, prevent conflicts from ever starting, and maintain better productivity while boosting morale.: One of the only trade publications that takes the manager's perspective on how to address conflicts, resolve disputes, and restore peace and productivity to t

  9. Java all-in-one for dummies



    Everything you need to get going with Java! Java All-in-One For Dummies, 4th Edition has what you need to get up and running quickly with Java. Covering the enhanced mobile development and syntax features as well as programming improvements, this guide makes it easy to find what you want and put it to use. Focuses on the vital information that enables you to get up and running quickly with Java Covers the enhanced multimedia features as well as programming enhancements, Java and XML, Swing, server-side Java, Eclipse, and more Minibooks cover Java basics; programming basics; strings, arrays,

  10. Access 2007 forms and reports for dummies

    Underdahl, Brian


    Do you have tons and tons of data on your computer but you're not quite sure how to make heads or tails of them-or even organize them? Are you using Access as spreadsheet rather than what it was really meant for? If you have trouble finding meaning in your data, then Access 2007 Forms & Reports for Dummies let you discover the wonders of this highly useful program. This no-nonsense guide gets right down to business by showing you the easy way to use this powerful tool. It gets you started with selective, targeted queries; forms that improve efficiency; and reports that communicate-while sparin

  11. SharePoint 2013 for dummies

    Withee, Ken


    The bestselling guide on running SharePoint, now updated to cover all the new features of SharePoint 2013 SharePoint Portal Server is an essential part of the enterprise infrastructure for many businesses. Building on the success of previous versions of SharePoint For Dummies, this new edition covers all the latest features of SharePoint 2013 and provides you with an easy-to-understand resource for making the most of all that this version has to offer. You'll learn how to get a site up and running, branded, and populated with content, workflow, and management. In addition, t

  12. Samsung Galaxy S6 for dummies

    Hughes, Bill


    Explore the capabilities of your Samsung Galaxy S 6 with this definitive guide! Learning to use a new phone can be both difficult and frustrating. With confusing documentation and baffling support, the references provided by phone manufacturers can be intimidating. Enter Samsung Galaxy S 6 For Dummies! This extensive yet practical guide walks you through the most useful features of your new Samsung Galaxy S 6-and it shows you all the best tricks to getting the most out of your device. With an accessible and fun, yet informative writing style, this is a text that you'll refer to again and agai

  13. Electronics all-in-one for dummies

    Ross, Dickon


    Your one-stop UK shop for clear, concise explanations to all the important concepts in electronics and tons of direction for building simple, fun electronic projects. The 8 mini-books in this 1 volume include: Getting Started with ElectronicsWorking with Basic ComponentsWorking with Integrated CircuitsGetting into Alternating CurrentWorking with Radio and InfraredDoing Digital ElectronicsWorking with Basic Stamp ProcessorsBuilding Special Effects With nearly 900 pages of instruction, Electronics All-in-One For Dummies covers all the bases and provides a fascinating hands-on exploration of el

  14. Office 2008 for Mac for dummies

    LeVitus, Bob


    Office 2008 for Mac is here, with great new enhancements to all your favorite office productivity tools. Who better than "Dr. Mac, "Bob LeVitus, to show you how to load and use them all? From choosing the best version for your needs to managing your life with your online calendar, Office 2008 For Mac For Dummies covers what you need to know. It compares the Student/Teacher Edition, Standard Edition, and Professional Edition, then walks you through installing your preferred version and keeping it up to date. You'll find out all the things you can do with Word, Excel, PowerPoint, and Entourage,

  15. Beginning programming with Java for dummies

    Burd, Barry


    A practical introduction to programming with Java Beginning Programming with Java For Dummies, 4th Edition is a comprehensive guide to learning one of the most popular programming languages worldwide. This book covers basic development concepts and techniques through a Java lens. You'll learn what goes into a program, how to put the pieces together, how to deal with challenges, and how to make it work. The new Fourth Edition has been updated to align with Java 8, and includes new options for the latest tools and techniques. Java is the predominant language used to program Android and cloud app

  16. Beginning Programming with Java For Dummies

    Burd, Barry


    One of the most popular beginning programming books, now fully updated Java is a popular language for beginning programmers, and earlier editions of this fun and friendly guide have helped thousands get started. Now fully revised to cover recent updates for Java 7.0, Beginning Programming with Java For Dummies, 3rd Edition is certain to put more first-time programmers and Java beginners on the road to Java mastery.Explores what goes into creating a program, putting the pieces together, dealing with standard programming challenges, debugging, and making the program work Offers new options for

  17. PowerPoint 2013 for dummies

    Lowe, Doug


    Get up and running with this full-color guide to PowerPoint 2013! PowerPoint, the number one presentation software, has been revised and improved with the introduction of Microsoft Office 2013. With this all-new, full-color book by your side, you will learn how to take full advantage of all of PowerPoint's powerful and dynamic capabilities. Bestselling veteran For Dummies, author Doug Lowe breaks it all down so that you can create a powerful and effective slideshow presentation with the new wide-screen theme and variant that incorporates videos, pictures, and shapes, and all

  18. AutoCAD 2014 for dummies

    Fane, Bill


    Find your way around AutoCAD 2014 with this full-color, For Dummies guide!Put away that pencil and paper and start putting the power of AutoCAD 2014 to work in your CAD projects and designs. From setting up your drawing environment to using text, dimensions, hatching, and more, this guide walks you through AutoCAD basics and provides you with a solid understanding of the latest CAD tools and techniques. You'll also benefit from the full-color illustrations that mirror exactly what you'll see on your AutoCAD 2014 screen and highlight the importance of AutoCAD's Mode

  19. Beginning programming with C for dummies

    Gookin, Dan


    Learn the basics of programming with C with this fun and friendly guide! C offers a reliable, strong foundation for programming and serves as a stepping stone upon which to expand your knowledge and learn additional programming languages. Written by veteran For Dummies author Dan Gookin, this straightforward-but-fun beginner's guide covers the fundamentals of using C and gradually walks you through more advanced topics including pointers, linked lists, file I/O, and debugging. With a special focus on the subject of an Integrated Development Environment, it gives you a solid understanding of

  20. PowerPoint 2007 for Dummies

    Lowe, Doug


    New and inexperienced PowerPoint users will discover how to use the latest enhancements to PowerPoint 2007 quickly and efficiently so that they can produce unique and informative presentations PowerPoint continues to be the world's most popular presentation software This updated For Dummies guide shows users different ways to create powerful and effective slideshow presentations that incorporate data from other applications in the form of charts, clip art, sound, and video Shares the key features of PowerPoint 2007 including creating and editing slides, working with hyperlinks and action butt

  1. Office 2011 for Mac For Dummies

    LeVitus, Bob


    Get started with Office 2011 for Mac and discover the creative possibilitiesThe leading suite of productivity software for the Mac, Microsoft Office helps users complete common business tasks, including word processing, e-mail, presentations, financial analysis, and much more. Office 2011 for Mac For Dummies is the perfect companion for Microsoft Office for Mac users upgrading to the newest version, new computer users, and those who may have switched from the Windows version of Office. Written by one of the most popular gurus in the Mac community, Bob "Dr. Mac" LeVitus, the book explains every

  2. C++ all-in-one for dummies

    Mueller, John Paul


    Get ahead of the C++ curve to stay in the game C++ is the workhorse of programming languages and remains one of the most widely used programming languages today. It's cross-platform, multi-functional, and updates are typically open-source. The language itself is object-oriented, offering you the utmost control over data usage, interface, and resource allocation. If your job involves data, C++ proficiency makes you indispensable. C++ All-in-One For Dummies, 3rd Edition is your number-one handbook to C++ mastery. Author John Paul Mueller is a recognized authority in the computer industry, and yo

  3. Office 2010 Web Apps For Dummies

    Weverka, Peter


    Enhance your Microsoft Office 2010 experience with Office 2010 Web Apps!. Office Web Apps complement Office, making it easy to access and edit files from anywhere. It also simplifies collaboration with those who don't have Microsoft Office on their computers. This helpful book shows you the optimum ways you can use Office Web Apps to save time and streamline your work. Veteran For Dummies author Peter Weverka begins with an introduction to Office Web Apps and then goes on to clearly explain how Office Web Apps provide you with easier, faster, more flexible ways to get things done.: Walks you t

  4. iBooks Author For Dummies

    Gruman, en


    Design and create your own e-book using the groundbreaking iBooks Author app With Apple's iBooks Author app, you can create rich, interactive books for use on the iPad, and this new For Dummies handy portable guide shows you just how to do it. Whether you want to create textbooks, training materials, marketing reports, or awesome product manuals with dynamic content, this book takes you through the process. Plunge in, and you'll soon learn how to create an iPad e-book with all the bells and whistles, including video, interactive widgets, text, tables, figures, colors, cool fonts, and more. Hel

  5. Switching to a Mac For Dummies

    Reinhold, Arnold


    Thinking of making the switch from your PC to a Mac? Congratulations! You're in for a great, virus-free ride. And Switching to Mac For Dummies makes it smoother than you ever imagined. From buying the Mac that's right for you to transferring your files to breaking your old Windows habits and learning to do things the (much easier) Mac way, it makes the whole process practically effortless. Whether you've been using Windows XP, Vista, or even Linux, you'll find simple, straightforward ways to make your transition go smoothly. That will leave you plenty of time to get familiar with Mac'

  6. Beginning programming with Python for dummies

    Mueller, John Paul


    Learn Python-the fun and easy way-and get in the programming game today! Python is one of the fastest growing programming languages, and no wonder. It requires three to five times less time than developing in Java, is a great building block for learning both procedural and object-oriented programming concepts, and is an ideal language for data analysis. Beginning Programming with Python For Dummies is the perfect guide to this dynamic and powerful programming language-even if you''ve never coded before! Author John Paul Mueller draws on his vast programming knowledge and experience to guide yo

  7. Pre-calculus workbook for dummies

    Kuang, Yang


    Get the confidence and math skills you need to get started with calculus Are you preparing for calculus? This hands-on workbook helps you master basic pre-calculus concepts and practice the types of problems you'll encounter in the course. You'll get hundreds of valuable exercises, problem-solving shortcuts, plenty of workspace, and step-by-step solutions to every problem. You'll also memorize the most frequently used equations, see how to avoid common mistakes, understand tricky trig proofs, and much more. Pre-Calculus Workbook For Dummies is the perfect tool for anyone who wa

  8. Samsung Galaxy Tab S for dummies

    Gookin, Dan


    Explore your Galaxy Tab S with an expert tour guide at your side Samsung Galaxy Tab S For Dummies is a user-friendly guide to getting the most out of your new tablet. You'll discover how different the tablet experience is from the desktop, laptop, or smartphone, and learn how to take advantage of everything your Galaxy Tab S has to offer. This entertaining guide walks you through each feature one by one, helping you learn exactly what your tablet can do for you. With everything from reading to playing games and surfing the Internet, you will learn how to be productive and have fun, too! Nav

  9. Samsung Galaxy S4 for dummies

    Hughes, Bill


    Explore a world of possibilities with your Samsung Galaxy S 4 smartphone Everything's more exciting when you've got the Galaxy in your hand. Let For Dummies be your guide to getting the most out of your Galaxy S 4. You'll cruise through the smartphone basics and set up process before moving on to the fun stuff like staying in touch with e-mail and texting, surfing the web, navigating with maps, shooting and sharing photos and video, watching movies, listening to music, and so much more. Whether you're entering the smartphone world for the first time or just moving up to

  10. WordPress web design for dummies

    Sabin-Wilson, Lisa


    Updated, full-color guide to creating dynamic websites with WordPress 3.6 In this updated new edition, bestselling For Dummies author and WordPress expert Lisa Sabin-Wilson makes it easy for anyone with a basic knowledge of the WordPress software to create a custom site using complementary technologies such as CSS, HTML, PHP, and MySQL. You'll not only get up to speed on essential tools and technologies and further advance your own design skills, this book also gives you pages of great case studies, so you can see just how other companies and individuals are creating compelling, customized, a

  11. iPod touch For Dummies

    Bove, Tony


    The ultimate beginner guide to the iPod touch, now updated and in full-color! Part media player, portable game console, and breakthrough Internet device, you could say that the iPod touch is one ideal gadget. With this new, full-color edition, bestselling For Dummies author Tony Bove walks you through powering up your iPod touch, personalizing it, establishing a Wi-Fi connection, and synchronizing your data. You'll also explore how to surf the web, rent movies, buy songs, send and receive e-mail, get directions, check stocks, organize photos, watch videos, keep a calendar, and much more. Plus,

  12. Home recording for musicians for dummies

    Strong, Jeff


    Invaluable advice that will be music to your ears! Are you thinking of getting started in home recording? Do you want to know the latest home recording technologies? Home Recording For Musicians For Dummies will get you recording music at home in no time. It shows you how to set up a home studio, record and edit your music, master it, and even distribute your songs. With this guide, you?ll learn how to compare studio-in-a-box, computer-based, and stand-alone recording systems and choose what you need. You?ll gain the skills to manage your sound, take full advantage of MIDI, m

  13. SketchUp 2014 for dummies

    Chopra, Aidan


    Start building your 3D model today with a comprehensive guide to SketchUp 2014 SketchUp 2014 For Dummies is a user-friendly guide to creating 3D models, adding textures, creating animated walkthroughs, and more, using one of the most popular 3D modeling programs on the market. Fully updated to align with the release of SketchUp, the book guides you through the interface, tools, techniques, and tricks in SketchUp and SketchUp Pro, on both Windows and Mac platforms. Written for designers with no prior 3D modeling experience, the book provides beginner- to intermediate-level instruction in this p

  14. Macs all-in-one for dummies

    Hutsko, Joe


    Your all-in-one guide to unleashing your Mac's full potential It's a Mac world out there. But if you haven't read the instruction manual, you may be neglecting some of your computer's coolest features. Turn to Macs All-in-One For Dummies' jam-packed guide to access the incredible tools within your computer. With this fully updated reference, you will learn how to use Launchpad and Mission Control; protect your Mac; back up and restore data with Time Machine; sync across devices in iCloud; import, organize, and share photos; direct in iMovie; compose in GarageBand; and so much more. The possi

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

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


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

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

    Kawada, E; Sakurai, Y; Oda, Y


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

  17. Evaluation of dummy behavior during low severity rear impact

    Cappon, H.J.; Philippens, M.M.G.M.; Ratingen, M.R. van; Wismans, J.S.H.M.


    Given the serious consequences of neck injuries resulting from rear-end collisions, this collision type has gained much attention lately. The low g loading levels and diffuse injuries require a crash dummy with an improved response compared to the available crash dummies. In the EC sponsored

  18. CMP dummy pattern based on VSB writer load

    Sakata, Wakahiko; Osawa, Isaku; Narukawa, Shogo; Takikawa, Tadahiko; Mohri, Hiroshi


    The load of VSB-EB mask writers has significantly increased since particularly RET/OPC and CMP dummy pattern generation technologies were widely adopted into designs at advanced nodes, with the result that the volume of mask data patterns was increased exponentially. In order to reduce the load of VSB mask writer, we've focused on CMP dummy patterns and developed a method of reducing CMP dummy pattern, which can smartly write CMP dummy patterns without not only deteriorating the CMP effects by them and also increasing the total number of the mask writer's shot count. To that end, we are aiming to establish a VSB-mask-writer-friendly CMP dummy pattern generation flow with CMP simulator developers by providing a mask writer parameter for them. This paper shows the first experimental results of our mask writer's load reduction work.

  19. Comparison of face Recognition Algorithms on Dummy Faces

    Aruni Singh


    Full Text Available In the age of rising crime face recognition is enormously important in the contexts of computer vision, psychology, surveillance, fraud detection, pattern recognition, neural network, content based video processing, etc. Face is a non intrusive strong biometrics for identification and hence criminals always try to hide their facial organs by different artificial means such as plastic surgery, disguise and dummy. The availability of a comprehensive face database is crucial to test the performance of these face recognition algorithms. However, while existing publicly-available face databases contain face images with a wide variety of poses, illumination, gestures and face occlusions but there is no dummy face database is available in public domain. The contributions of this research paper are: i Preparation of dummy face database of 110 subjects ii Comparison of some texture based, feature based and holistic face recognition algorithms on that dummy face database, iii Critical analysis of these types of algorithms on dummy face database.

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

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


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

  1. Computer simulation of solder joint failure

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


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

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

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


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

  3. Effect of Solder Flux Residues on Corrosion of Electronics

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


    Flux from ‘No Clean’ solder processes can cause reliability problems in the field due to aggressive residues, which may be electrical conducting or corrosive in humid environments. The solder temperature during a wave solder process is of great importance to the amount of residues left on a PCBA[...

  4. Efforts to Develop a 300°C Solder

    Norann, Randy A [Perma Works LLC


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

  5. Microstructural evolution of eutectic Au-Sn solder joints

    Song, Ho Geon


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

  6. Microstructural evolution of eutectic Au-Sn solder joints

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


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

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

    Espy, P. N.


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

  8. Thermal decomposition of solder flux activators under simulated wave soldering conditions

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


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

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

    M. Provazník; R. Koleňák


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

  10. A novel method for direct solder bump pull testing using lead-free solders

    Turner, Gregory Alan

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

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

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


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

  12. iPad application development for dummies

    Goldstein, neal


    Making Everything Easier!With iPhone? Application Development for Dummies, Second Edition, you'll learn to: Design small- or large-scale iPhone applications for profit or fun Create new iPhone apps using Xcode? Get your applications into the App Store Work with frameworks Got a good idea? Turn it into an app, have some fun, and pick up some cash!Make the most of the new 3.1 OS and Apple's Xcode 3.2! Neal Goldstein shows you how, and even illustrates the process with one of his own apps that's currently being sold. Even if you're not a programming pro, you can turn your bright idea into an app

  13. SharePoint 2007 Collaboration For Dummies

    Harvey, Greg


    If you're looking for a way to help your teams access what they need to know, work together, and get the job done, SharePoint can do just that. SharePoint 2007 Collaboration For Dummies shows you the easiest way to set up and customize SharePoint, manage your data, interact using SharePoint blogs and wikis, integrate Office programs, and make your office more productive. You'll learn what SharePoint can do and how to make it work for your business, understand the technical terms, and enable your people to collaborate on documents and spreadsheets. You'll even discover how to get SharePoint hel

  14. iPad For Seniors For Dummies

    Muir, Nancy C


    The full-color guide to the exciting new iPad, written specifically with the needs of seniors in mind!. The iPad is the perfect device for the senior market, combining the Web, e-mail, photos, video, and book reading into an intuitive, portable device. Written by veteran Dummies author Nancy Muir, this fun and friendly guide shows you how to use the many features and capabilities of the iPad to make life easier! You'll learn how to use the multitouch screen to zoom in and out on Web pages and choose a font and size that makes reading comfortable so that you can get directions, plan vacations,

  15. iOS app development for dummies

    Feiler, Jesse


    If you've got incredible iOS ideas, get this book and bring them to life! iOS 7 represents the most significant update to Apple's mobile operating system since the first iPhone was released, and even the most seasoned app developers are looking for information on how to take advantage of the latest iOS 7 features in their app designs. That's where iOS App Development For Dummies comes in! Whether you're a programming hobbyist wanting to build an app for fun or a professional developer looking to expand into the iOS market, this book will walk you through the fundamentals of building a univer

  16. Solder Joint Health Monitoring Testbed System

    Delaney, Michael M.


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

  17. Pb-Free Soldering Iron Temperature Controller

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

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

  18. Nanocopper Based Solder-Free Electronic Assembly

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


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

  19. Basic math and pre-algebra practice problems for dummies

    Zegarelli, Mark


    1001 Basic Math & Pre- Algebra Practice Problems For  Dummies   Practice makes perfect-and helps deepen your understanding of basic math and pre-algebra 1001 Basic Math & Pre-Algebra Practice Problems For Dummies, with free access to online practice problems, takes you beyond the instruction and guidance offered in Basic Math & Pre-Algebra For Dummies, giving you 1,001 opportunities to practice solving problems from the major topics in your math course. You begin with some basic arithmetic practice, move on to fractions, decimals, and per

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

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


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

  1. Parametric study on the solderability of etched PWB copper

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


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

  2. Lead (Pb)-Free Solder Applications



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

  3. Effects of PCB thickness on adjustable fountain wave soldering

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


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

  4. Solder flow over fine line PWB surface finishes

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


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

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

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


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

  6. Capillary flow of solder on chemically roughened PWB surfaces

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


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

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

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


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

  8. Single Point Incremental Forming using a Dummy Sheet

    Skjødt, Martin; Silva, Beatriz; Bay, Niels


    A new version of single point incremental forming (SPIF) is presented. This version includes a dummy sheet on top of the work piece, thus forming two sheets instead of one. The dummy sheet, which is in contact with the rotating tool pin, is discarded after forming. The new set-up influences...... the process and furthermore offers a number of new possibilities for solving some of the problems appearing in SPIF. Investigations of the influence of dummy sheet on: formability, wear, surface quality and bulging of planar sides is done by forming to test shapes: a hyperboloid and a truncated pyramid....... The possible influence of friction between the two sheets is furthermore investigated. The results show that the use of a dummy sheet reduces wear of the work piece to almost zero, but also causes a decrease in formability. Bulging of the planar sides of the pyramid is reduced and surface roughness...

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

    Ji, Hongjun; Wang, Qiang; Li, Mingyu


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

  10. Multilead, Vaporization-Cooled Soldering Heat Sink

    Rice, John


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

  11. Soldering and Mass Generation in Four Dimensions

    Banerjee, R; Banerjee, Rabin; Wotzasek, Clovis


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

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

    Jarboe, D.M.


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

  13. Microwave Tissue Soldering for Immediate Wound Closure

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


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

  14. Preparation of solder pads by selective laser scanning

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


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

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

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


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

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

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


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

  17. Investigation of Solder Cracking Problems on Printed Circuit Boards

    Berkebile, M. J.


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

  18. Assessment of potential solder candidates for high temperature applications

    Multi-Chip module (MCM) technology is a specialized electronic packaging technology recently gaining momentum due to the miniaturization drive in the microelectronics industry. The step soldering approach is being employed in the MCM technology. This method is used to solder various levels...... of the package with different solders of different melting temperatures. High Pb containing alloys where the lead levels can be above 85% by weight, is one of the solders currently being used in this technology. Responding to market pressure i.e. need for green electronic products there is now an increasing...... criterion, phases predicted in the bulk solder and the thermodynamic stability of chlorides. These promising solder candidates were precisely produced using the hot stage microscope and its respective anodic and cathodic polarization curves were investigated using a micro-electrochemical set up...

  19. Anomalous creep in Sn-rich solder joints

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


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



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

  1. Solderability preservation through the use of organic inhibitors

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


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

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

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


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

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

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


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

  4. Recent Research Trend in Laser-Soldering Process

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


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

  5. Attitudes to the use of dummies in New Zealand; a qualitative study.

    Vogel, A; Mitchell, E A


    To explore experiences with, and attitudes to, the use of dummies (pacifiers). Seven focus group discussions were held with groups of mothers and of health professionals. Most mothers and health care workers had a generally negative view of dummy use. This related particularly to dislike of toddlers with them and practical issues such as getting lost or dirty. All would allow their use in a very unsettled baby. No mothers had personally experienced problems with breastfeeding due to the use of a dummy, but concern about this possibility was expressed by some health care workers. Recommendations varied about the length of time that dummies need to be avoided. Mothers in New Zealand use dummies selectively for their infants and were concerned with issues of weaning the baby from the dummy, keeping it clean and not losing it. In analysing the relationships between dummy use and breastfeeding it is important to take into consideration the context of dummy use.

  6. Responses of side impact dummies in sled tests.

    Yoganandan, Narayan; Pintar, Frank A


    Sled tests were conducted at a velocity of 6.7 m/s using side impact dummies (SID, BioSID, ES-2, and WorldSIDp) and the resulting biomechanical responses were compared with responses from post mortem human subjects (PMHS). Initial impact conditions were with and without pelvic offset in combination with and without padding on the impacting wall. Impact forces, thoracic trauma index, chest compression, and viscous criteria were evaluated. The probability of injury was estimated and rates of deformation were computed for each body region. Dummy responses were not always similar in terms of trend and injury criteria when compared with PMHS tests under the same initial conditions. Response variations will be of value in improving the biofidelity characteristics of dummies for crashworthiness evaluations.

  7. Reliability Study of Solder Paste Alloy for the Improvement of Solder Joint at Surface Mount Fine-Pitch Components

    Mohd Nizam Ab. Rahman


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

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

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


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

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

    M. Provazník


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

  10. Home Networking Do-It-Yourself For Dummies

    Miller, Lawrence C


    Step by step guide to connecting all your electronic devices into one network A home network allows you to share Internet connections, photos, video, music, game consoles, printers, and other electronic gadgets. This do-it-yourself guide shows you step by step how to create a wired or wireless network in your home. In the For Dummies tradition of making technology less intimidating, Home Networking Do-It-Yourself For Dummies breaks down the process into easy steps with clear instructions.Increasing broadband speeds, cellular technology, the explosive growth of iPhone sales, and the new Home Gr

  11. Influences of pre-crash braking induced dummy - forward displacements on dummy behaviour during EuroNCAP frontal crashtest.

    Woitsch, Gernot; Sinz, Wolfgang


    Combination of active and passive safety systems is a future key to further improvement in vehicle safety. Autonomous braking systems are able to reduce collision speeds, and therefore severity levels significantly. Passengers change their position due to pre-impact vehicle motion, a fact, which has not yet been considered in common crash tests. For this paper, finite elements simulations of crash tests were performed to show that forward displacements due to pre-crash braking do not necessarily increase dummy load levels. So the influence of different pre-crash scenarios, all leading to equal closing speeds in the crash phase, are considered in terms of vehicle motion (pitching, deceleration) and restraint system configurations (belt load limiter, pretensioner). The influence is evaluated by dummy loads as well as contact risk between the dummy and the interior. Copyright © 2013 Elsevier Ltd. All rights reserved.

  12. Surface tension and reactive wetting in solder connections

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


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

  13. Assessment of potential solder candidates for high temperature applications

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

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

    Davidson, R.N.


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

  15. A Study of Solder Alloy Ductility for Cryogenic Applications

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


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

  16. Hybrid microcircuit board assembly with lead-free solders

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


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

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



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

  18. Development of lead-free solders for hybrid microcircuits

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


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

  19. On-chip inductor above dummy metal patterns

    Hsu, Heng-Ming; Hsieh, Ming-Ming


    This work characterizes the on-chip inductor above dummy metals in CMOS technology. Since the dummy pattern influences the sheet resistance in chemical-mechanical planarization (CMP) process strongly [Schindler G, Steinlesberger G, Engelhardt M, Steinhögl W. Electrical characterization of copper interconnects with end-of-roadmap feature sizes. Solid-State Electron 2003;47:1233-36; Smith S, Walton AJ, Ross AWS, Bodammer GKH, Stevenson JTM. Evaluation of sheet resistance and electrical line width measurement techniques for copper damascene interconnect. IEEE Trans Semicond Manuf 2002;15:214-22.], three test structures are fabricated to compare the inductor performances in this paper. The measurements show that the Q value degrades 15.3% and self-resonance frequency decreases 9.5% in device with dummy metal pattern. Accordingly, an equivalent circuit is proposed to analyze this behavior, the results show that the insulator capacitor plays a key role in performance degradation. Result of this study quantifies the effect of on-chip inductor above dummy pattern.

  20. Worldsid small female side impact dummy specifications and prototype evaluation

    Been, B.W.; Meijer, R.; Bermond, F.; Bortenschlager, K.; Hynd, D.; Martinez, L.; Ferichola, G.


    The WorldSID program was set up to develop a new, worldwide acceptable, advanced technology, side impact crash test dummy for improved assessment of injury risk to car occupants in lateral collisions. Following the release of the mid-sized male WorldSID, the development of the small female WorldSID

  1. Leadership for Dummies: A Capstone Project for Leadership Students

    Moore, Lori L.; Odom, Summer F.; Wied, Lexi M.


    Capstone courses in leadership provide students opportunities to synthesize prior knowledge about various aspects of leadership. This article describes the "Leadership for Dummies" project, which could be used as a capstone experience for leadership majors. Based on his experiences as a psychological researcher, Gardner (2008) identified five…

  2. Duality Symmetry and Soldering in Different Dimensions

    Banerjee, R


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

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

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


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

  4. Environmentally compatible solder materials for thick film hybrid assemblies

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


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

  5. Simulation of thermomechanical fatigue in solder joints

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


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

  6. Albumin-genipin solder for laser tissue welding

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


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

  7. Mechanical Reliability of Aged Lead-­Free Solders

    Lewin, Susanne


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

  8. Solder technology in the manufacturing of electronic products

    Vianco, P.T.


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

  9. Age-Infusion Approach to Derive Injury Risk Curves for Dummies from Human Cadaver Tests

    Yoganandan, Narayan; Banerjee, Anjishnu; Pintar, Frank A.


    Injury criteria and risk curves are needed for anthropomorphic test devices (dummies) to assess injuries for improving human safety. The present state of knowledge is based on using injury outcomes and biomechanical metrics from post-mortem human subject (PMHS) and mechanical records from dummy tests. Data from these models are combined to develop dummy injury assessment risk curves (IARCs)/dummy injury assessment risk values (IARVs). This simple substitution approach involves duplicating dummy metrics for PMHS tested under similar conditions and pairing with PMHS injury outcomes. It does not directly account for the age of each specimen tested in the PMHS group. Current substitution methods for injury risk assessments use age as a covariate and dummy metrics (e.g., accelerations) are not modified so that age can be directly included in the model. The age-infusion methodology presented in this perspective article accommodates for an annual rate factor that modifies the dummy injury risk assessment responses to account for the age of the PMHS that the injury data were based on. The annual rate factor is determined using human injury risk curves. The dummy metrics are modulated based on individual PMHS age and rate factor, thus “infusing” age into the dummy data. Using PMHS injuries and accelerations from side-impact experiments, matched-pair dummy tests, and logistic regression techniques, the methodology demonstrates the process of age-infusion to derive the IARCs and IARVs. PMID:26697422

  10. Age-Infusion Approach to Derive Injury Risk Curves for Dummies from Human Cadaver Tests.

    Yoganandan, Narayan; Banerjee, Anjishnu; Pintar, Frank A


    Injury criteria and risk curves are needed for anthropomorphic test devices (dummies) to assess injuries for improving human safety. The present state of knowledge is based on using injury outcomes and biomechanical metrics from post-mortem human subject (PMHS) and mechanical records from dummy tests. Data from these models are combined to develop dummy injury assessment risk curves (IARCs)/dummy injury assessment risk values (IARVs). This simple substitution approach involves duplicating dummy metrics for PMHS tested under similar conditions and pairing with PMHS injury outcomes. It does not directly account for the age of each specimen tested in the PMHS group. Current substitution methods for injury risk assessments use age as a covariate and dummy metrics (e.g., accelerations) are not modified so that age can be directly included in the model. The age-infusion methodology presented in this perspective article accommodates for an annual rate factor that modifies the dummy injury risk assessment responses to account for the age of the PMHS that the injury data were based on. The annual rate factor is determined using human injury risk curves. The dummy metrics are modulated based on individual PMHS age and rate factor, thus "infusing" age into the dummy data. Using PMHS injuries and accelerations from side-impact experiments, matched-pair dummy tests, and logistic regression techniques, the methodology demonstrates the process of age-infusion to derive the IARCs and IARVs.

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

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


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

  12. Web Sites Do-It-Yourself for Dummies

    Warner, Janine


    A step-by-step guide to creating your first Web site. Everybody's building cool web sites, but how? Web Sites Do-It-Yourself For Dummies, 2nd Edition , shows you how, with simple, step-by-step instruction that will build your confidence as you build your site. You'll learn to plan your site and secure a domain name, how to use Dreamweaver for site construction, and how to test and publish your site. You'll also learn about designing a blog, creating a podcast, adding Flash, and even how to make money with your Web site. Dummies makes it easy and fun!: Perfect for those who've never attempted a

  13. Comparison of FEA Calculations with Cryostat Dummy Weight Test Results

    Guarino, V


    Extensive Finite Element analyses were performed to determine the loads and stresses acting on the EB and Barrel during assembly and in its final configuration. Up to now it has been difficult to verify the FEA results due to the unusual compression at the inner radius shims has resulted in larger than anticipated deflections. The cryostat dummy load test offers the first real chance for a direct comparison between the deflections of the Tilecal and the FEA model. By comparing the difference in position of the FM's before the cryostat load was applied and afterwards it is possible to eliminate all other variables and compare directly with the FEA model. This paper will present a comparison between the FEA model and the survey measurements for when the cryostat dummy weight load was applied at 32 modules and 46 modules in place.

  14. iPod and iTunes for dummies

    Bove, Tony


    Get going with your iPod & iTunes and this perennial bestseller - now in full-color! iPod & iTunes For Dummies is the ultimate beginner's guide for getting started with your iPod and Apple's iTunes service. Now in its tenth edition, this helpful guide has been completely overhauled and boasts a full-color format for the first time ever. Veteran For Dummies author Tony Bove introduces you to the different iPod models, explains how to power up your iPod, and shows you how to set up iTunes. You'll learn to personalize your device, add music tracks from a CD to your iTune

  15. Biomechanical analysis of injury criterion for child and adult dummies.

    Sances, A


    The development of human injury tolerance is difficult because of the physical differences between humans and animals, the available dummies, and tissue of the cadaver. Furthermore, human volunteer testing can clearly only be done at subinjurious levels. While considerable biomechanical injury evidence exists for the adult human based on cadaveric studies, little information is available for the pediatric population. However, some material is available from skull bone modulus studies and from the fetal tendon strength and early pediatric studies of the newborn. A review of living human, animal, and human cadaveric studies, which forms the basis for head-neck injury criterion are given. Examples of the use of the Hybrid III dummy for injury prediction such as in the Malibu rollover tests and air bag mechanisms show neck injury levels are considerably above the proposed Malibu 2000 N level.

  16. HTML5 eLearning kit for dummies

    Boumphrey, Frank


    Helping self-directed learners of all levels learn HTML5 If you want to develop and structure pages for the web, HTML5 is one of the tools you need. This invaluable eLearning kit steps you through learning HTML5, CSS3, and JavaScript. With this dynamic combination of a full-color printed book and a Dummies interactive eLearning course on CD, you'll find a wealth of information on HTML5. Featuring both written and animated step-by-step how-tos, practice labs, helpful videos, numerous examples, and a host of Dummies hints and tips, this package makes your learning process easier. Follow the mate

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

    Liu Mei Lee


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

  18. The dentate gyrus: fundamental neuroanatomical organization (dentate gyrus for dummies).

    Amaral, David G; Scharfman, Helen E; Lavenex, Pierre


    The dentate gyrus is a simple cortical region that is an integral portion of the larger functional brain system called the hippocampal formation. In this review, the fundamental neuroanatomical organization of the dentate gyrus is described, including principal cell types and their connectivity, and a summary of the major extrinsic inputs of the dentate gyrus is provided. Together, this information provides essential information that can serve as an introduction to the dentate gyrus--a "dentate gyrus for dummies."

  19. Rear impact responses of different sized adult Hybrid III dummies.

    DeRosia, John; Yoganandan, Narayan; Pintar, Frank A


    Rear impact sled tests were conducted using 5th, 50th, and 95th percentile Hybrid III dummies to evaluate proposed injury criteria. Different head restraint height (750, 800 mm) and backset (0, 50, 100 mm) positions were used to determine axial and shear forces, bending moments, and injury criteria (NIC, N(ij), and N(km)). The time sequence to attain each parameter was also determined. Three events were identified in the response. Event I was coincident with the maximum rearward motion of the torso, Event II occurred at the time of the peak upper neck flexion moment, and Event III occurred at the time of maximum rearward motion of the head. Parameters such as backset, head restraint height, seat-head restraint interaction, and anthropometry affected impact responses. Head rotations increased with increasing backset and increasing head restraint height. However, N(ij) and N(km) did not exhibit such clear trends. The 50th percentile dummy responded with consistent injury criteria values (e.g., the magnitude of the injury criteria increased with backset increase or head restraint height decrease). However, the 5th and 95th percentile dummies did not demonstrate such trends. These findings underscore the need to include subject anthropometry in addition to seat and head restraint characteristics for better assessment of rear impact responses.

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

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


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

  1. Development of gold based solder candidates for flip chip assembly

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


    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...

  2. Method of defence of solder surface from oxidization

    Kurmashev Sh. D.


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

  3. Effect of bottles, cups, and dummies on breast feeding in preterm infants: a randomised controlled trial.

    Collins, Carmel T; Ryan, Philip; Crowther, Caroline A; McPhee, Andrew J; Paterson, Susan; Hiller, Janet E


    To determine the effect of artificial teats (bottle and dummy) and cups on breast feeding in preterm infants. Randomised controlled trial. Two large tertiary hospitals, 54 peripheral hospitals. 319 preterm infants (born at 23-33 weeks' gestation) randomly assigned to one of four groups: cup/no dummy (n = 89), cup/dummy (n = 72), bottle/no dummy (n = 73), bottle/dummy (n = 85). Women with singleton or twin infants Dummies do not affect breast feeding in preterm infants. Cup feeding significantly increases the likelihood that the baby will be fully breast fed at discharge home, but has no effect on any breast feeding and increases the length of hospital stay.

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

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


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

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

    Liu Mei Lee; Ahmad Azmin Mohamad


    This paper reviews the function and importance of Sn-Ag-Cu solder alloys in electronics industry and the interfacial reaction of Sn-Ag-Cu/Cu solder joint at various solder forms and solder reflow conditions. The Sn-Ag-Cu solder alloys are examined in bulk and in thin film. It then examines the effect of soldering conditions to the formation of intermetallic compounds such as Cu substrate selection, structural phases, morphology evolution, the growth kinetics, temperature and time is also disc...

  6. WorldSID Dummy Head-Neck Biofidelity Response.

    Been, Bernard; Philippens, Mat; de Lange, Ronald; van Ratingen, Michiel


    Accident studies indicate that serious neck injuries are generally infrequent in side crashes. However, given the rapid changes in side impact protection technology, such as side airbags and curtain systems, the nature of head-neck interactions is likely to change. Consequently, the newest generation of anthropomorphic test devices for side impact should provide realistic prediction of the head-neck kinematics and include meaningful measurements related to risk of head and neck injury. The WorldSID dummy has been assessed against a set of five test conditions that have been used to define biofidelity impact response targets. Three of the five test conditions are recommended by ISO TR9790 (ISO 1997), the NBDL 7.2 G, 6.9 m/s lateral sled impact reported by Ewing et al. (1977) and Wismans et al. (1986) , the Patrick and Chou lateral, 6.7 G 5.8 m/s (1976) and Tarriere lateral 12.2 g, 6,1 m/s sled impact (ISO 1997). Due to its expected loading environment, the dummy neck performance has also been evaluated for neck bending in frontal flexion and extension (Mertz and Patrick, 1971). The 5th test condition is the NBDL 45 degrees frontal-oblique sled test (Wismans 1986, Philippens 2004). The latter and two of the ISO TR9790 test conditions form the basis of the draft IHRA requirements for evaluating side impact dummy biomechanical responses. The paper reports on the findings of the assessment of the WorldSID pre-production dummy. The Mertz and Patrick OC moment-head angle corridor is used as supplemental requirement for frontal flexion-extension. The biofidelity requirements contain both kinematic and dynamic response targets. The neck has a good performance for NBDL lateral and Tarriere requirements, and the Mertz OC moment-flexion angle. The performance for the Patrick and Chou, the NBDL oblique test conditions and the Mertz OC moment extension angle are fair to marginal. The repeatability performance of the dummy was found to be good for all lateral and most oblique

  7. Design of the dummy coil for magnet power supply

    Kim, Chang-Hwan, E-mail:; Choi, Jae-Hoon; Jin, Jong-Kook; Lee, Dong-Keun; Kong, Jong-Dea; Joung, Nam-Young; Kim, Sang-Tae; Kim, Young-Jin; Kim, Yang-Soo; Kwon, Myeun


    Highlights: • It is necessary to confirm safety of the MPS on a dummy coil before the operating it. • We selected and designed the water cooling type dummy coil to test on the MPS's rating (12.5 kA) test. • For the design of the dummy coil, we considered requirements about electrical, structural and water cooling. • We will test as the rating power after MPS upgrade and that test will do before every KSTAR campaign. -- Abstract: It is necessary to test it on a dummy coil, before using a magnet power supply (MPS) to energize a Poloidal Field (PF) coil in the Korea Superconducting Tokamak Advanced Research (KSTAR) device. The dummy coil should accept the same large current from the MPS as the PF coil and be within the capability of the utilities located at the KSTAR site. Therefore a coil design based on the characteristics of the MPS and other restrictive conditions needed to be made. There are three requirements to be met in the design: an electrical requirement, a structural requirement, and a water cooling requirement. The electrical requirement was that the coil should have an inductance of 40 mH. For the structural requirement, the material should be non magnetic. The coil support structure and water cooling manifold were made of SUS 304. The water cooling requirement was that there should be sufficient flow rate so that the temperature rise ΔT should not exceed 12 °C for operation at 12.5 kA for 5 min. Square cross-section hollow conductor with dimensions of 38.1 mm × 38.1 mm was used with a 25.4 mm center hole for cooling water. However, as a result of tests, it was found that the electrical and structural requirements were satisfied but that the water cooling was over designed. It is imperative that the verification will be redone for a test with 12.5 kA for 5 min.

  8. Microsurgical anastomosis of sperm duct by laser tissue soldering

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


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

  9. Laser Soldering of Rat Skin Using a Controlled Feedback System

    Mohammad Sadegh Nourbakhsh


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

  10. Creep properties of Pb-free solder joints

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


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

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

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


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

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

    Byrne, Gerard


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

  13. Soldering of Thin Film-Metallized Glass Substrates

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


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

  14. Lead-free solder technology transfer from ASE Americas



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

  15. Age infusion approach to derive injury assessment risk curves for dummies from human cadaver tests

    Narayan eYoganandan


    Full Text Available Injury criteria and risk curves are needed for anthropomorphic test devices (dummies to assess injuries for improving human safety. The present state of knowledge is based on using injury outcomes and biomechanical metrics from post-mortem human subject (PMHS and mechanical records from dummy tests. Data from these models are combined to develop dummy injury assessment risk curves/values (IARCs and IARVs. This simple substitution approach involves duplicating dummy metrics for PMHS tested under similar conditions and pairing with PMHS injury outcomes. It does not account for the age of each specimen tested in the PMHS group. Current substitution methods for injury risk assessments use age as a covariate and dummy metrics (e.g., accelerations are not modified so that age can be directly included in the model. The age-infusion methodology presented in this perspective article accommodates for an annual rate factor that modifies the dummy injury risk assessment responses to account for the age of the PMHS that the injury data was based on. The annual rate factor is determined using human injury risk curves. The dummy metrics are modulated based on individual PMHS age and rate factor, thus infusing age into the dummy data. Using PMHS injuries and accelerations from side-impact experiments, matched-pair dummy tests and logistic regression techniques, the methodology demonstrates the process of age-infusion to derive the IARCs and IARVs.

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

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


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

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

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


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

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

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


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

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

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


    In order to reduce or even replace the use of Sn-Pb solder in electronics industry, the laser-textured surface microstructures were used to enhance the wetting behavior of lead free solder during soldering. According to wetting theory and Sn-Ag-Cu lead free solder performance, we calculated and designed four microcosmic structures with the similar shape and different sizes to control the wetting behavior of lead free solder. The micro-structured surfaces with different dimensions were processed on copper plates by fiber femtosecond laser, and the effect of microstructures on wetting behavior was verified experimentally. The results showed that the wetting angle of Sn-Ag-Cu solder on the copper plate with microstructures decreased effectively compared with that on the smooth copper plate. The wetting angles had a sound fit with the theoretical values calculated by wetting model. The novel method provided a feasible route for adjusting the wetting behavior of solders and optimizing solders system.

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

    Fuquan LI; Chunqing WANG; Yanhong TIAN


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

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

    Miller, C.M.


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

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

    Chen, Gang; Zhao, Xiaochen; Wu, Hao


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

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

    Hocheng, H; Hong, T; Jadhav, U


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

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

    Woods, Bobby


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

  5. iPad all-in-one for dummies

    Muir, Nancy C


    For iPad users who want more information than the basics of the iPad,  iPad All-in-One For Dummies provides the goods! Based on Apple's new iOS software, which includes Siri for iPad, new and improved maps with turn by turn directions, shared photo streams, Facebook integration, Passbook, FaceTime video calls over cellular, new calling features such as instant text reply and callback reminders, improved email with a VIP inbox, iCloud browsing tabs, and much more. The book is organized into the following minibooks: iPad Basics - Covers basic functionality, synching with your computer and getti

  6. Photoshop CS6 all-in-one for dummies

    Obermeier, Barbara


    Everything you need to know about the newest version of Photoshop packed into one For Dummies guide Photoshop is the world’s most popular image editing software, with more than four million users worldwide. Professional photographers, graphic designers, and Web designers as well as photo hobbyists need to learn the fundamentals and master the newest features of the latest version of Photoshop - Photoshop CS6. This complete all-in-one reference makes it easy, with eight self-contained minibooks covering each aspect of Photoshop. Helps you familiarize yourself with the latest Photos

  7. HTML5 programming with JavaScript for dummies

    Mueller, John Paul


    Web designers and programmers, add JavaScript to your HTML5 development toolkit without fear Modern websites are complex, and some of the most exciting features - things like geolocation, canvas, portability to mobile and more - require JavaScript to leverage what HTML5 can create. Don't know JavaScript? That's where HTML5 Programming with JavaScript For Dummies comes in. Rather than walking you through JavaScript as a programming language, it approaches JavaScript as a tool to help you enhance web pages. Helps web designers and programmers tap the full power of HT

  8. Pre-calculus 1,001 practice problems for dummies

    Sterling, Mary Jane; Sterling


    Prepare for calculus the smart way, with customizable pre-calculus practice 1,001 Pre-Calculus Practice Problems For Dummies offers 1,001 opportunities to gain confidence in your math skills. Much more than a workbook, this study aid provides pre-calculus problems ranked from easy to advanced, with detailed explanations and step-by-step solutions for each one. The companion website gives you free online access to all 1,001 practice problems and solutions, and you can track your progress and ID where you should focus your study time. Accessible on the go by smart phone, tablet, o

  9. Basic math and pre-algebra for dummies

    Zegarelli, Mark


    Tips for simplifying tricky basic math and pre-algebra operations Whether you're a student preparing to take algebra or a parent who wants or needs to brush up on basic math, this fun, friendly guide has the tools you need to get in gear. From positive, negative, and whole numbers to fractions, decimals, and percents, you'll build necessary math skills to tackle more advanced topics, such as imaginary numbers, variables, and algebraic equations. Explanations and practical examples that mirror today's teaching methodsRelevant cultural vernacular and referencesStandard For Dummies materials that

  10. Mac OS X Snow Leopard Server For Dummies

    Rizzo, John


    Making Everything Easier!. Mac OS® X Snow Leopard Server for Dummies. Learn to::;. Set up and configure a Mac network with Snow Leopard Server;. Administer, secure, and troubleshoot the network;. Incorporate a Mac subnet into a Windows Active Directory® domain;. Take advantage of Unix® power and security. John Rizzo. Want to set up and administer a network even if you don't have an IT department? Read on!. Like everything Mac, Snow Leopard Server was designed to be easy to set up and use. Still, there are so many options and features that this book will save you heaps of time and effort. It wa

  11. Excel 2010 all-in-one for dummies

    Harvey, Greg


    A comprehensive, up-to-date, user-friendly guide to Excel 2010 Excel is the standard for spreadsheet applications and is used worldwide, but it's not always user-friendly. That makes it a perfect For Dummies topic, and this handy all-in-one guide covers all the essentials, the new features, how to analyze data with Excel, and much more. Eight minibooks address Excel basics, worksheet design, formulas and functions, worksheet collaboration and review, charts and graphics, data management, data analysis, and Excel and VBA.Excel is the leading spreadsheet/data analysis s

  12. OS X Yosemite all-in-one for dummies

    Chambers, Mark L


    Get the most out of the latest version of OS X This reference combines eight content-rich minibooks in one complete package to give you all-access, easy-to-understand coverage of the key features and tools needed to get the most out of the latest OS X release from Apple. In OS X Yosemite All-in-One For Dummies, you'll learn the ins and outs of OS X basics, navigating and running programs, searching with Spotlight, having fun with Photo Booth, keeping in touch with Contacts, using Reminders, writing in Notes, setting up the Notification Center, customizing the OS X desktop, jamming with iTunes,

  13. Business Skills All-in-One For Dummies

    Burton, Kate


    Fulfil your workplace potential with this indispensable handbook. Written by a team of experts, Business Skills All-in-One For Dummies is your complete guide to perfecting your communication, management and organizational skills. Inside you'll find simple techniques for improving your performance at work - everything from presentation skills, project management, persuading and influencing people, motivating (yourself and others!), managing your workload, managing a team and much more. No other book offers you this much in one volume. It's like having a whole team of business, communication and

  14. Visual Studio 2010 All-in-One For Dummies

    Moore, Andrew


    A comprehensive, easy-to-understand guide to Visual Studio 2010. Visual Studio is Microsoft's comprehensive development environment that encompasses the .NET Framework, various programming languages, and ASP.NET. Programmers love it for developing applications for mobile devices and the Web. Because Visual Studio can be complex, the All-in-One For Dummies format makes it easy for beginners to grasp its different parts and get up to speed.: Visual Studio is a development environment used with various programming languages to create a variety of applications, including those for the Web and mobi

  15. Office 2010 all-in-one for dummies

    Weverka, Peter


    The leading book on Microsoft Office, now fully updated for Office 2010 Microsoft Office, the world's leading productivity suite, has been updated with new tools. Veteran Office users as well as newcomers will need the comprehensive information in this bestselling All-in-One guide. With a self-contained minibook devoted to each Office application plus minibooks on how Office works together and how you can expand its usefulness, Office 2010 All-in-One For Dummies gets you up to speed and answers the questions you'll have down the road.Microsoft Office is the office pro

  16. Windows 7 eLearning Kit For Dummies

    Fulton, Jennifer


    Self-motivators will get moving with Windows 7 using this interactive eLearning course! Windows 7 is the number one operating system in the world and if you're eager to get started using all it has to offer, this value-packed eLearning kit is essential to your learning process. A complete Microsoft Windows 7 course, it includes a full-color printed book and a Dummies interactive eLearning course on CD. Each lesson opens with an introduction to the content and explains the importance and potential uses for every task described. Featuring both written and animated step-by-step how-tos, practice

  17. BlackBerry All-in-One for Dummies

    Sarigumba, Dante; Petz, William


    Go beyond BlackBerry basics and get everything your BlackBerry can deliver. BlackBerry is the leading smartphone for business users, and its popularity continues to explode. When you discover the amazing array of BlackBerry possibilities in this fun and friendly guide, you'll be even happier with your choice of smartphones. BlackBerry All-in-One For Dummies explores every feature and application common to all BlackBerry devices. It explains the topics in depth, with tips, tricks, workarounds, and includes detailed information about cool new third-party applications, accessories, and downloads

  18. Consistent differences in individual reactions to drugs and dummies

    Joyce, C. R. B.


    The tendency of some individuals to report changes of physical and mental state after taking pharmacologically inert substances has been investigated experimentally. In a class of healthy medical students, those individuals who reported symptoms and those who did not made significantly different scores on a number of behavioural tests. The likely reactions of the members of a second class (containing none of the previous participants) to dummies were then predicted from their scores on the same tests, some of which were found to be much more efficient predictors than would have been expected by chance. Some implications for further research and for clinical medicine are discussed. PMID:14408028

  19. OS X Mavericks all-in-one for dummies

    Chambers, Mark L


    Your all-in-one guide to all things OS X Mavericks This fun and friendly For Dummies guide is your ticket to taking advantage of all the features of Apple's latest desktop operating system - OS X Mavericks. You'll get to know OS X, customize Mavericks for your needs, become more productive, and take your system to a whole new level with eight minibooks dedicated to OS X essentials. Plus, you'll learn how to keep your system safe, stay connected on the go, turn your Mac into a multimedia hub, and make your Mac happy with the over 200 new features found in OS X Mavericks. Includes eight minibo

  20. Cisco Networking All-in-One For Dummies

    Tetz, Edward


    A helpful guide on all things Cisco Do you wish that the complex topics of routers, switches, and networking could be presented in a simple, understandable presentation? With Cisco Networking All-in-One For Dummies, they are! This expansive reference is packed with all the information you need to learn to use Cisco routers and switches to develop and manage secure Cisco networks. This straightforward-by-fun guide offers expansive coverage of Cisco and breaks down intricate subjects such as networking, virtualization, and database technologies into easily digestible pieces. Drills down complex

  1. Office 2010 eLearning Kit For Dummies

    Wempen, Faithe


    Create and work with Microsoft Office 2010 with this learning package Microsoft Office 2010 is the most commonly used office productivity suite and if you're eager to get started using all it has to offer, this value-packed eLearning kit is essential to your learning process. This complete Microsoft Office 2010 course includes a full-color printed book and a Dummies interactive eLearning course on CD. You'll discover the basics of the Office interface, how to navigate it, and how to use the features common to all Office programs. Then you'll get detailed instruction in working with Word, Excel

  2. MacBook All-in-One For Dummies

    Chambers, Mark L


    Get comfortable and confident with your MacBook! Combining the fun-but-straightforward content of nine minibooks, this new edition of MacBook All-in-One For Dummies delivers helpful coverage of the rich features and essential tools you need to know to use the MacBook to its fullest potential. You'll learn an array of MacBook basics while veteran author Mark Chambers walks you through setting up your MacBook, running programs, finding files with Finder, searching with Spotlight, keeping track with Address Book, enjoying music with iTunes, creating cool multimedia projects with iLife, and more.

  3. CCNA Certification All-In-One For Dummies

    Angelescu, Silviu


    A complete preparation guide for the entry-level networking CCNA certification. If you're planning to advance your career by taking the all-important Cisco Certified Network Associate (CCNA), this is the study guide you need! Seven minibooks cover all the concepts and topics on which you'll be tested, covering the latest version of the exam. Each part of the exam is covered thoroughly in its own section, so you can readily find the information you want to study. Plenty of review questions help you prepare, and the companion CD-ROM includes the highly rated Dummies Test Engine so you can test y

  4. Networking All-in-One Desk Reference for Dummies

    Lowe, Doug


    An essential one-stop resource-nine convenient minibooks in a single 840page volume-for network administrators everywhere; This value-priced package includes sections on networking basics, building a network, network administration, TCP/IP and the Internet, wireless and home networking, Windows 2000 and 2003 servers, NetWare 6, Linux networking, and; Mac OS X networking; Written by the author of the perennial bestseller Networking For Dummies (0-7645-1677-9), this massive reference covers all the topics that administrators routinely handle; Provides key information, explanations, and procedure

  5. Methylene blue solder re-absorption in microvascular anastomoses

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


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

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

    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

  7. A Corrosion Investigation of Solder Candidates for High-Temperature Applications

    Chidambaram, Vivek; Hald, John; Ambat, Rajan;


    The step soldering approach is being employed in the Multi-Chip module (MCM) technology. High lead containing alloys is one of the solders currently being used in this approach. Au-Sn and Au-Ge based candidate alloys have been proposed as alternative solders for this application. In this work, co...

  8. 30 CFR 77.1916 - Welding, cutting, and soldering; fire protection.


    ... 30 Mineral Resources 1 2010-07-01 2010-07-01 false Welding, cutting, and soldering; fire... OF UNDERGROUND COAL MINES Slope and Shaft Sinking § 77.1916 Welding, cutting, and soldering; fire protection. (a) One portable fire extinguisher shall be provided where welding, cutting, or soldering...

  9. 30 CFR 77.1112 - Welding, cutting, or soldering with arc or flame; safeguards.


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

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

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


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

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

    Nagy E.


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

  12. Experimental Methods in Reduced-gravity Soldering Research

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


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

  13. Low-temperature solder for laser tissue welding

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


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

  14. Evolution of egg dummies in Tanganyikan cichlid fishes: the roles of parental care and sexual selection.

    Amcoff, M; Gonzalez-Voyer, A; Kolm, N


    Sexual selection has been suggested to be an important driver of speciation in cichlid fishes of the Great Lakes of Africa, and the presence of male egg dummies is proposed to have played a key role. Here, we investigate how mouthbrooding and egg dummies have evolved in Tanganyikan cichlids, the lineage which seeded the other African radiations, with a special emphasis on the egg dummies. Using modern phylogenetic comparative analyses and a phylogeny including 86% of the 200 described species, we provide formal evidence demonstrating correlated evolution between mouthbrooding and egg dummies in Tanganyikan cichlids. These results concur with existing evidence, suggesting that egg dummies have evolved through sensory exploitation. We also demonstrate that there is a strong evolutionary correlation between the presence of egg dummies and both pre- and post-copulatory sexual selection. Moreover, egg dummy evolution was contingent on the intensity of pre- and post-copulatory sexual selection in Tanganyikan cichlids. In sum, our results provide evidence supporting the hypothesis of egg dummies evolving through sensory exploitation and highlight the role of sexual selection in favouring the evolution and maintenance of this trait. © 2013 The Authors. Journal of Evolutionary Biology © 2013 European Society For Evolutionary Biology.

  15. Prediction and validation of the Q3 child dummy airbag response

    Twisk, D.; Ratingen, M.R. van; Schrooten, M.


    The paper describes the use of FE modeling in the design process of the new Q child dummies, in particular the upper thorax. The model has been used to optimize the design of the ribcage, by making the changes in rib mass, material thickness, properties, etc., so that the dummy response meets the de

  16. Creep characterization of solder bumps using nanoindentation

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


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

  17. Bottom-up nanoarchitecture of semiconductor nano-building blocks by controllable in situ SEM-FIB thermal soldering method

    Zhang, Xuan


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

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

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


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

  19. An Overview of Surface Finishes and Their Role in Printed Circuit Board Solderability and Solder Joint Performance

    Vianco, P.T.


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

  20. Evaluating the Vibration Isolation of Soft Seat Cushions Using AN Active Anthropodynamic Dummy

    LEWIS, C. H.; GRIFFIN, M. J.


    Seat test standards require human subjects to be used for measuring the vibration isolation of vehicle seats. Anthropodynamic dummies, based on passive mass-spring- damper systems, have been developed for testing seats but their performance has been limited at low excitation magnitudes by non-linear phenomena, such as friction in the mechanical components that provide damping. The use of an electrodynamic actuator to generate damping forces, controlled by feedback from acceleration and force transducers, may help to overcome these limitations and provide additional benefits. The transmissibilities of five foam cushions have been measured using an actively controlled anthropodynamic dummy, in which damping and spring forces were supplied by an electrodynamic actuator. The dummy could be set up to approximate alternative single-degree-of-freedom and two-degree-of-freedom apparent mass models of the seated human body by varying motion feedback parameters. Cushion transmissibilities were also measured with nine human subjects, having an average seated weight similar to the dummy. At frequencies greater than 4 Hz, mean cushion transmissibilities measured with subjects were in closer agreement with the transmissibilities obtained with a two degree-of-freedom dummy than with a single degree-of-freedom dummy. However, at frequencies between 2 and 4 Hz, cushion transmissibilities obtained with the two-degree-of-freedom dummy showed consistently larger differences from mean transmissibilities with subjects than single-degree-of-freedom dummies, indicating a need for further development of human apparent mass models to account for the effects of magnitude and spectral content of the input motion. Vertical vibration isolation efficiencies (SEAT values) of the five foams were measured with four input motions, including three motions measured in a car. The SEAT values obtained using the active dummy were highly correlated with the median SEAT values obtained with the nine human

  1. Horizon Shells and BMS-like Soldering Transformations

    Blau, Matthias


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

  2. Development of alternatives to lead-bearing solders

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


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

  3. Bosonisation and Duality Symmetry in the Soldering Formalism

    Banerjee, R


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

  4. Corrosion Issues in Solder Joint Design and Service



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

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

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


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

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

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


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

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



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

  8. A new active solder for joining electronic components



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

  9. Lead Free Solder Joint Thermal Condition in Semiconductor Packaging

    M. N. Harif


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

  10. Integrated optical MEMS using through-wafer vias and bump-bonding.

    McCormick, Frederick Bossert; Frederick, Scott K.


    This LDRD began as a three year program to integrate through-wafer vias, micro-mirrors and control electronics with high-voltage capability to yield a 64 by 64 array of individually controllable micro-mirrors on 125 or 250 micron pitch with piston, tip and tilt movement. The effort was a mix of R&D and application. Care was taken to create SUMMiT{trademark} (Sandia's ultraplanar, multilevel MEMS technology) compatible via and mirror processes, and the ultimate goal was to mate this MEMS fabrication product to a complementary metal-oxide semiconductor (CMOS) electronics substrate. Significant progress was made on the via and mirror fabrication and design, the attach process development as well as the electronics high voltage (30 volt) and control designs. After approximately 22 months, the program was ready to proceed with fabrication and integration of the electronics, final mirror array, and through wafer vias to create a high resolution OMEMS array with individual mirror electronic control. At this point, however, mission alignment and budget constraints reduced the last year program funding and redirected the program to help support the through-silicon via work in the Hyper-Temporal Sensors (HTS) Grand Challenge (GC) LDRD. Several months of investigation and discussion with the HTS team resulted in a revised plan for the remaining 10 months of the program. We planned to build a capability in finer-pitched via fabrication on thinned substrates along with metallization schemes and bonding techniques for very large arrays of high density interconnects (up to 2000 x 2000 vias). Through this program, Sandia was able to build capability in several different conductive through wafer via processes using internal and external resources, MEMS mirror design and fabrication, various bonding techniques for arrayed substrates, and arrayed electronics control design with high voltage capability.

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

    Choi, Sunglak


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

  12. iPad all-in-one for dummies

    Muir, Nancy C


    Six minibooks in one show you how to power-use the iPad For work, play, and life on the road, the iPad has quickly become indispensable, and the new iPad is packed with even more features and power than ever. In this fun and practical guide, long-time For Dummies author Nancy C. Muir walks you through the latest functions, features, and capabilities of the iPad. Get up to speed on the basics, see how to use your iPad to get more organized and productive, learn to use your iPad for work, and discover all the ways to have fun. This book covers it all, and in full color! Packs six minibooks in on

  13. PCs all-in-one desk reference for dummies

    Chambers, Mark L


    Need the scoop on Windows Vista? How about Office 2007? Anything you need to know about using your PC can probably be found in PCs All-In-One Desk Reference for Dummies, 4th Edition. This handy guide is made up of eight convenient minibooks, so you can find what you need in a hurry. And in case you think you've seen it before, this fourth edition is fully updated for all the newest, coolest stuff. Want a guided tour of the Vista operating system and how it differs from XP? Check out minibook #2. Have you heard about Microsoft Works but aren't sure what it's about? Find out

  14. Office 2013 eLearning kit for dummies

    Wempen, Faithe


    Unlock your new Office with this one-of-a-kind learning package! Whether you're meeting Office 2013 for the first time or upgrading your knowledge from an earlier version, this value-packed eLearning kit makes it easy to learn 2013 at your own pace. This complete learning package includes a full-color printed book and a Dummies interactive eLearning course on CD. You'll learn the basics of the Office interface, how to navigate it, and how to use the features common to all Office programs. Then you'll get detailed instructions for working with Word, Excel, PowerPoint, and Outlook. Follow the

  15. Watermarking Java Programs using Dummy Methods with Dynamically Opaque Predicates

    Akbar, Zaenal


    Software piracy, the illegal using, copying, and resale of applications is a major concern for anyone develops software. Software developers also worry about their applications being reverse engineered by extracting data structures and algorithms from an application and incorporated into competitor's code. A defense against software piracy is watermarking, a process that embeds a secret message in a cover software. Watermarking is a method that does not aim to stop piracy copying, but to prove ownership of the software and possibly even the data structures and algorithms used in the software. The language Java was designed to be compiled into a platform independent bytecode format. Much of the information contained in the source code remains in the bytecode, which means that decompilation is easier than with traditional native codes. In this thesis, we present a technique for watermarking Java programs by using a never-executed dummy method (Monden, 2000) combined with opaque predicates (Collberg

  16. Word 2010 eLearning Kit For Dummies

    Lowe, Lois


    Use this step-by-step learning package to master Word 2010 Word 2010 is one of the core applications of Microsoft Office and if you're eager to get started using all it has to offer, this value-packed eLearning Kit is essential to your learning process. This complete Word 2010 course includes a full-color printed book and a Dummies interactive eLearning course on CD. You'll discover the basics of the Word interface, how to navigate it, how to get comfortable with the terminology, and how to use its many features. Detailed instructions walk you through real-world exercises and help to make lear

  17. BlackBerry PlayBook For Dummies

    Sandler, Corey


    Use your BlackBerry PlayBook for work and for play—this book shows you how For all you business road warriors who don't go anywhere without your BlackBerrys, the road just got a little more comfortable. The BlackBerry PlayBook is a tablet is your go-to-gadget for working on the go. Learn how to take full advantage of this powerful newcomer to the tablet market with this full-color For Dummies guide. You'll discover how to use your PlayBook to connect to corporate systems, manage your finances, keep track of your travel and other schedules—even how to use the PlayBook as an e-reade

  18. Office for iPad and Mac for dummies

    Weverka, Peter


    The easy way to work with Office on your iPad or Mac Are you a Mac user who isn't accustomed to working with Microsoft Office? Consider this friendly guide your go-to reference! Written in plain English and packed with easy-to-follow, step-by-step instructions, Office for iPad and Mac For Dummies walks you through every facet of Office, from installing the software and opening files to working with Word, Excel, PowerPoint, and Outlook-and beyond. Plus, you'll discover how to manage files, share content and collaborate online through social media, and find help when you need it. Two things a

  19. High-temperature lead-free solder alternatives

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


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

  20. Thermomechanical fatigue damage evolution in SAC solder joints

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


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

  1. Porosity in collapsible Ball Grid Array solder joints

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


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

  2. Fundamentals of wetting and spreading with emphasis on soldering

    Yost, F.G.


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

  3. Horizon shells and BMS-like soldering transformations

    Blau, Matthias; O'Loughlin, Martin


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

  4. Thermomechanical fatigue damage evolution in SAC solder joints

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


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

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

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

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

  6. Horizon shells and BMS-like soldering transformations

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


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

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

    Lucheva, Biserka; Tsonev, Tsonio; Iliev, Peter


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

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

    Liu, Pilin

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


    Y.H.Tian; C.Q.Wang


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

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

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


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

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

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


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

  12. Guidelines for assessing the biofidelity of side impact dummies of various sizes and ages.

    Irwin, Annette L; Mertz, Harold J; Elhagediab, Ali M; Moss, Steve


    The Human Mechanical Simulation Subcommittee of the Human Biomechanics and Simulation Standards Committee of the Society of Automotive Engineers took on the task of defining test procedures and associated response guidelines to be used to assess the level of biofidelity of side impact dummies that are being developed. This paper describes the results of their efforts. Guidelines are provided for assessing the levels of biofidelity of dummies that represent 6-, 12-, and 18-month-old infants, 3-, 6-, and 10-year-old children, and of dummies that represent a small female, midsize male and large male adults. These guidelines were developed by normalizing the side impact biofidelity guidelines that were established by the International Standards Organization for the head, neck, shoulder, thorax, abdomen and pelvis of the midsize adult male. The ISO guidelines can be used to define biofidelity guidelines for any size or age of dummy provided pertinent geometric, inertial and tissue properties are specified.

  13. Comparison of Hybrid III and THOR dummies in paired small overlap tests.

    Mueller, Becky C; Sherwood, Christopher P; Arbelaez, Raul A; Zuby, David S; Nolan, Joseph M


    The Insurance Institute for Highway Safety (IIHS) is investigating small overlap crash test procedures for a possible consumer information program. Analysis of real-world small overlap crashes found a strong relationship between serious head and chest injuries and occupant compartment intrusion. The main sources of serious head injuries were from the A-pillar, dash panel, or door structure, suggesting head trajectories forward and outboard possibly bypassing the airbag. Chest injuries mainly were from steering wheel intrusion and seat belt loading. In developing this program, two test dummies were evaluated for predicting occupant injury risk: midsize male Hybrid III and THOR. In the collinear small overlap crash tests conducted here, results from the two dummies were similar. Both predicted a low risk of injury to the head and chest and sometimes a high risk of injury to the lower extremities. Head and torso kinematics also were similar between dummies. Other test scenarios might show larger differences between the dummies.

  14. Sensitivity of THOR and Hybrid III dummy lower neck loads to belt systems in frontal impact.

    Yoganandan, Narayan; Pintar, Frank A; Moore, Jason; Maiman, Dennis J


    To determine head-neck biomechanics with a focus on lower neck injury metrics in frontal impact. The mid- and large-size Hybrid III dummies and the mid-size Test device for Human Occupant Restraint (THOR) were positioned on a buck. Tests were conducted at low, medium, and high (3.3, 6.7, and 15.7 m/s) change in velocities using 3 restraint types: normal 3-point belt with no pretension (type A), 10-cm pretension (type B), and 200 N pretension (type C). Repeat tests were conducted. Measured vertical and shear forces and sagittal bending moments were evaluated at the upper and lower regions of the neck to different types of belt systems and at different change in velocities. Peak values normalized with respect to the belt type A were used in the comparative analysis. Metrics transformed to the occipital condyles and T1 were also evaluated. All dummies showed good repeatability. Peak measured and transformed upper and lower neck moments were greatest in the large-size dummy. The mid-size Hybrid III dummy responded with greater forces and moments than the THOR. Regardless of dummy type, anthropometry, and velocity, peak lower neck moments were more sensitive to belt types than peak lower neck forces. A similar pattern was apparent for upper neck data. Moments in the THOR were more sensitive than moments in the mid-size Hybrid III dummy. This study offers quantitative generic restraint-based data and addresses response differences between dummies and dummies of the same family. Because of increased sensitivity to belt types at the upper and lower necks for both forces and moments, the THOR appears to be an improvement to better assess injury potential to rear seat occupants wherein frontal impact air bags do not exist.

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

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


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

  16. Controlled Impact Demonstration instrumented test dummies installed in plane


    In this photograph are seen some of dummies in the passenger cabin of the B-720 aircraft. NASA Langley Research Center instrumented a large portion of the aircraft and the dummies for loads in a crashworthiness research program. In 1984 NASA Dryden Flight Research Facility and the Federal Aviation Adimistration (FAA) teamed-up in a unique flight experiment called the Controlled Impact Demonstration (CID). The test involved crashing a Boeing 720 aircraft with four JT3C-7 engines burning a mixture of standard fuel with an additive called Anti-misting Kerosene (AMK) designed to supress fire. In a typical aircraft crash, fuel spilled from ruptured fuel tanks forms a fine mist that can be ignited by a number of sources at the crash site. In 1984 the NASA Dryden Flight Research Facility (after 1994 a full-fledged Center again) and the Federal Aviation Administration (FAA) teamed-up in a unique flight experiment called the Controlled Impact Demonstration (CID), to test crash a Boeing 720 aircraft using standard fuel with an additive designed to supress fire. The additive, FM-9, a high-molecular-weight long-chain polymer, when blended with Jet-A fuel had demonstrated the capability to inhibit ignition and flame propagation of the released fuel in simulated crash tests. This anti-misting kerosene (AMK) cannot be introduced directly into a gas turbine engine due to several possible problems such as clogging of filters. The AMK must be restored to almost Jet-A before being introduced into the engine for burning. This restoration is called 'degradation' and was accomplished on the B-720 using a device called a 'degrader.' Each of the four Pratt & Whitney JT3C-7 engines had a 'degrader' built and installed by General Electric (GE) to break down and return the AMK to near Jet-A quality. In addition to the AMK research the NASA Langley Research Center was involved in a structural loads measurement experiment, which included having instrumented dummies filling the seats in the

  17. Comparison of Hybrid III child test dummies to pediatric PMHS in blunt thoracic impact response.

    Parent, D P; Crandall, J R; Bolton, J R; Bass, C R; Ouyang, J; Lau, S H


    The limited availability of pediatric biomechanical impact response data presents a significant challenge to the development of child dummies. In the absence of these data, the development of the current generation of child dummies has been driven by scaling of the biomechanical response requirements of the existing adult test dummies. Recently published pediatric blunt thoracic impact response data provide a unique opportunity to evaluate the efficacy of these scaling methodologies. However, the published data include several processing anomalies and nonphysical features. These features are corrected by minimizing instrumentation and processing error to improve the fidelity of the individual force-deflection responses. Using these data, biomechanical impact response corridors are calculated for a 3-year-old child and a 6-year-old child. These calculated corridors differ from both the originally published postmortem human subject (PMHS) corridors and the impact response requirements of the current child dummies. Furthermore, the response of the Hybrid III 3-year-old test dummy in the same impact condition shows a similar deflection but a significantly higher force than the 3-year-old corridor. The response of the Hybrid III 6-year-old dummy, on the other hand, correlates well with the calculated 6-year-old corridor. The newly developed 3-year-old and 6-year-old blunt thoracic impact response corridors can be used to define data-driven impact response requirements as an alternative to scaling-driven requirements.

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


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

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

    CHENGuohai; MAJusheng


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

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

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


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

  1. Corrosive microenvironments at lead solder surfaces arising from galvanic corrosion with copper pipe.

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


    As stagnant water contacts copper pipe and lead solder (simulated soldered joints), a corrosion cell is formed between the metals in solder (Pb, Sn) and the copper. If the resulting galvanic current exceeds about 2 μA/cm(2), a highly corrosive microenvironment can form at the solder surface, with pH galvanic currents, preventing passivation of the solder surface, and contributing to lead contamination of potable water supplies. The total mass of lead corroded was consistent with predictions based on the galvanic current, and lead leaching to water was correlated with galvanic current. If the concentration of sulfate in the water increased relative to chloride, galvanic currents and associated lead contamination could be greatly reduced, and solder surfaces were readily passivated.

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

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


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


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


    Printed Circuit Boards (PCB) play an important role in the manufacturing of electronic devices. To ensure a correct function of the PCBs a certain amount of solder paste is needed during the placement of components. The aim of the current research is to develop an real-time, closed-loop solution for the analysis of the printing process where solder is printed onto PCBs. Close range photogrammetry allows for determination of the solder volume and a subsequent correction if necessary. ...

  4. Investigation of moisture uptake into printed circuit board laminate and solder mask materials

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


    Presence of moisture in a printed circuit board (PCB) laminate, typically made of glass fibres reinforced epoxy polymer, significantly influences the electrical functionality in various ways and causes problems during soldering process. This paper investigates the water uptake of laminates coated...... with different solder mask materials and exposed to saturated water vapour and liquid water. The solder masks are characterised for their microstructure and constituent phases using scanning electron microscopy and X-ray diffraction. The observations are correlated with themoisture absorption characteristic...

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

    and mechanical properties of these potential candidate alloys with respect to the currently used high-lead content solders is made. Finally, the paper presents the superior characteristics as well as some drawbacks of these proposed high-temperature lead-free solder alternatives....... the criteria for the evaluation of a new high-temperature lead-free solder material. A list of potential ternary high-temperature lead-free solder alternatives based on the Au-Sn and Au-Ge systems is proposed. Furthermore, a comprehensive comparison of the high-temperature stability of microstructures...

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

    Liu Haiping; Li Ning; Bi Sifu; Li Deyu


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

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

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


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

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

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


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

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

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


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

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



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

  11. Molecularly imprinted polymers with synthetic dummy templates for the preparation of capsaicin and dihydrocapsaicin from chili peppers.

    Ma, Xiuli; Ji, Wenhua; Chen, Lingxiao; Wang, Xiao; Liu, Jianhua; Wang, Xueyong


    In this work, dummy molecularly imprinted polymers with high selectivity and affinity to capsaicin and dihydrocapsaicin are designed using N-vanillylnonanamide as a dummy template. The performance of dummy molecularly imprinted polymers and nonimprinted polymers was evaluated using adsorption isotherms, adsorption kinetics, and selective recognition capacity. Dummy molecularly imprinted polymers were found to exhibit good site accessibility, taking just 20 min to achieve adsorption equilibrium; they were also highly selective toward capsaicin and dihydrocapsaicin. We successfully used dummy molecularly imprinted polymers as a specific sorbent for selectively enriching capsaicin and dihydrocapsaicin from chili pepper samples. In a scaled-up experiment, the selective recovery of capsaicinoids was calculated to be 77.8% using solid-phase extraction. To the best of our knowledge, this is the first example of the use of N-vanillylnonanamide as a dummy template in molecularly imprinted polymers to simultaneously enrich capsaicin and dihydrocapsaicin.

  12. Influence of Difference Solders Volume on Intermetallic Growth of Sn-4.0Ag-0.5Cu/ENEPIG

    Saliza Azlina O.


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

  13. On the other hand: dummy hands and peripersonal space.

    Makin, Tamar R; Holmes, Nicholas P; Ehrsson, H Henrik


    Where are my hands? The brain can answer this question using sensory information arising from vision, proprioception, or touch. Other sources of information about the position of our hands can be derived from multisensory interactions (or potential interactions) with our close environment, such as when we grasp or avoid objects. The pioneering study of multisensory representations of peripersonal space was published in Behavioural Brain Research almost 30 years ago [Rizzolatti G, Scandolara C, Matelli M, Gentilucci M. Afferent properties of periarcuate neurons in macaque monkeys. II. Visual responses. Behav Brain Res 1981;2:147-63]. More recently, neurophysiological, neuroimaging, neuropsychological, and behavioural studies have contributed a wealth of evidence concerning hand-centred representations of objects in peripersonal space. This evidence is examined here in detail. In particular, we focus on the use of artificial dummy hands as powerful instruments to manipulate the brain's representation of hand position, peripersonal space, and of hand ownership. We also review recent studies of the 'rubber hand illusion' and related phenomena, such as the visual capture of touch, and the recalibration of hand position sense, and discuss their findings in the light of research on peripersonal space. Finally, we propose a simple model that situates the 'rubber hand illusion' in the neurophysiological framework of multisensory hand-centred representations of space.

  14. Synchronous pulsing plasma utilization in dummy poly gate removal process

    Huang, Ruixuan; Meng, Xiao-Ying; Han, Qiu-Hua; Zhang, Hai-Yang


    When CMOS technology reaches 28/20nm node and beyond, several new schemes are implemented such as High K metal gate (HKMG) which can enhance the device performance and has better control of device current leakage. Dummy poly gate removal (DPGR) process is introduced for HKMG, and works as a key process to control the work function of metal gate and threshold voltage (Vt) shift. In dry etch technology, conventional continuous wave (CW) plasma process has been widely used, however, it may not be capable for some challenging process in 28nm node and beyond. In DPGR process for HKMG scheme, CW scheme may result in plasma damage of gate oxide/capping layer for its inherent high electron temperature (Te) and ion energy while synchronous pulsing scheme is capable to simultaneously pulse both source and bias power, which could achieve lower Te, independent control of ion and radical flux, well control the loading of polymer deposition on dense/ isolate features. It's the first attempt to utilize synchronous pulsing plasma in DPGR process. Experiment results indicate that synchronous pulsing could provide less silicon recess under thin gate oxide which is induced by the plasma oxidation. Furthermore, the loading of HK capping layer loss between long channel and short channel can be well controlled which plays a key role on transistor performance, such as leakage and threshold voltage shift. Additionally, it has been found that synchronous pulsing could distinctly improve ILD loss when compared with CW, which is helpful to broaden the whole process window.

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

    K. Arun Vasantha Geethan

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

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

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


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

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

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


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

  18. The influence of increased roof strength on belted and unbelted dummies in rollover and drop tests.

    Bahling, G S; Bundorf, R T; Moffatt, E A; Orlowski, K F


    This report condenses and summarizes two related and previously published reports. These two reports analyzed the effect of added roof strength on both belted and unbelted dummies. The reports, which have been dubbed Malibu I and Malibu II, respectively, presented data from a total of 16 rollover crash tests and four test conditions in which vehicles were dropped on their roofs. To evaluate the effect of roof strength, half of all test vehicles were modified to incorporate rigid rollcages, the other half were production vehicles. To evaluate the effect of belt restraints, half of all tests incorporated restrained dummies, the other half were unrestrained. The data from these tests clearly demonstrated that increased roof strength provided no reduction in dummy neck loads for belted or unbelted dummies when they were located over the area of the roof that impacted the ground. The tests also demonstrated that the neck loads resulted from "diving" type impacts, where the head stops and the torso momentum loads the neck. Roof deformation never caused the dummy to be compressed between the roof and seat.

  19. Head excursion of restrained human volunteers and hybrid III dummies in steady state rollover tests.

    Moffatt, Edward; Hare, Barry; Hughes, Raymond; Lewis, Lance; Iiyama, Hiroshi; Curzon, Anne; Cooper, Eddie


    Seatbelts provide substantial benefits in rollover crashes, yet occupants still receive head and neck injuries from contacting the vehicle roof interior when the roof exterior strikes the ground. Prior research has evaluated rollover restraint performance utilizing anthropomorphic test devices (dummies), but little dynamic testing has been done with human volunteers to learn how they move during rollovers. In this study, the vertical excursion of the head of restrained dummies and human subjects was measured in a vehicle being rotated about its longitudinal roll axis at roll rates from 180-to-360 deg/sec and under static inversion conditions. The vehicle's restraint design was the commonly used 3-point seatbelt with continuous loop webbing and a sliding latch plate. This paper presents an analysis of the observed occupant motion and provides a comparison of dummy and human motion under similar test conditions. Thirty-five tests (eighteen static and seventeen dynamic) were completed using two different sizes of dummies and human subjects in both near and far-side roll directions. The research indicates that far-side rollovers cause the restrained test subjects to have greater head excursion than near-side rollovers, and that static inversion testing underestimates head excursion for far-side occupants. Human vertical head excursion of up to 200 mm was found at a roll rate of 220 deg/sec. Humans exhibit greater variability in head excursion in comparison to dummies. Transfer of seatbelt webbing through the latch plate did not correlate directly with differences in head excursion.

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

    Yu, Hao


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

  1. Failure Mechanisms of SAC/Fe-Ni Solder Joints During Thermal Cycling

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


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

  2. Tissue soldering with biodegradable polymer films: in-vitro investigation of hydration effects on weld strength

    Sorg, Brian S.; Welch, Ashley J.


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

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

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


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

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

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


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

  5. Development of technique for laser welding of biological tissues using laser welding device and nanocomposite solder.

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


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

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

    Chidambaram, Vivek

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

  7. 30 CFR 77.1111 - Welding, cutting, soldering; use of fire extinguisher.


    ... 30 Mineral Resources 1 2010-07-01 2010-07-01 false Welding, cutting, soldering; use of fire... OF UNDERGROUND COAL MINES Fire Protection § 77.1111 Welding, cutting, soldering; use of fire extinguisher. One portable fire extinguisher shall be provided at each location where welding, cutting,...

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

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


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

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

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


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

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

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


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

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

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


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

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

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


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

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


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

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

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


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

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

    Idris Siti Rabiatull Aisha


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

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

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


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

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

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


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

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

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


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

  19. Properties and Microstructures of Sn-Bi-X Lead-Free Solders

    Fan Yang


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

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

    倪广春; 张浩; 韩敏


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

  1. Physical properties of lead free solders in liquid and solid state

    Mhiaoui, Souad


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

  2. Troubleshooting and Maintaining Your PC All-in-One Desk Reference For Dummies

    Gookin, Dan


    Maintaining a PC is important, and troubleshooting a PC can be a challenge. Dan Gookin is great at explaining how to handle common PC problems, and he's provided a complete, plain-English manual in Troubleshooting & Maintaining Your PC All-in-One For Dummies. Liberally laced with Dan's famous humor and clear instructions, Troubleshooting & Maintaining Your PC All-in-One For Dummies is divided into six minibooks covering hardware, software, laptops, Internet, networking, and maintenance. Each one gives you some background on what causes common problems, to help you understand what's wrong as we

  3. An effect of dummy cathode on thickness uniformity in electroforming process

    Chul-Woo Park


    Full Text Available This study examines the solution for one of the most difficult problems of electroforming process “thickness deviation”. As an effective solution, an auxiliary electrode (dummy cathode is considered. Generally, the thickness of an edge plating area is almost twice the center area or greater. An auxiliary electrode (intentionally attached dummy cathode has helped to achieve more uniform thickness of the electroformed-nickel layer by preventing excessive electric charge. In addition, computer-aided analysis was performed to determine the optimal condition of electroforming process and to confirm the experimental result.

  4. Reliability of Wind Turbine Components-Solder Elements Fatigue Failure

    Kostandyan, Erik; Sørensen, John Dalsgaard


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

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

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


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

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

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


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

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

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


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

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

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


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

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

    Khosroshahi, Mohammad E; Nourbakhsh, Mohammad S


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

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

    Tribula, D.


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

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

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


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

  12. Wettability Studies of Pb-Free Soldering Materials

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


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

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

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


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

  14. 77 FR 11651 - Hybrid III 10-Year-Old Child Test Dummy


    ... results, the agency is pursuing the development of an HIII-10C modification consisting of an abdominal.... Executive Summary II. Background a. 2005 NPRM b. Developments Since 2005 c. Summary of Decision III. Summary... 1. Labeling the Dummy as a ``Ten Year Old'' 2. Best Practices for Belt Routing 3. Abdominal...

  15. 16 CFR Figure 6 to Subpart A of... - Dummy Specimen in Specimen Holder


    ... 16 Commercial Practices 2 2010-01-01 2010-01-01 false Dummy Specimen in Specimen Holder 6 Figure 6 to Subpart A of Part 1209 Commercial Practices CONSUMER PRODUCT SAFETY COMMISSION CONSUMER PRODUCT SAFETY ACT REGULATIONS INTERIM SAFETY STANDARD FOR CELLULOSE INSULATION The Standard Pt. 1209, Subpt. A...

  16. A Note on the Effect of Seasonal Dummies on the Periodogram Regression

    M. Ooms (Marius); U. Hassler


    textabstractWe discuss how prior regression on seasonal dummies leads to singularities in periodogram regression procedures for the detection of long memory. We suggest a modified procedure. We illustrate the problems using monthly inflation data from Hassler and Wolters (1995).

  17. Dummies versus air puffs: efficient stimulus delivery for low-volatile odors.

    Brandstaetter, Andreas Simon; Rössler, Wolfgang; Kleineidam, Christoph Johannes


    Aiming to unravel how animals perceive odors, a variety of neurophysiological techniques are used today. For olfactory stimulation, odors are commonly incorporated into a constant airstream that carries odor molecules to the receptor organ (air-delivered stimulation). Such odor delivery works well for odors of high volatility (naturally effective over long distances) but less or not at all for low-volatile odors (usually only received at short range). We developed a new odor stimulation technique especially suited for low-volatile odors and compared it with conventional air-delivered stimulation using 2 neurophysiological approaches. Odor-loaded dummies were moved into close vicinity of the receptor organs on the antenna of the Florida carpenter ant Camponotus floridanus (dummy-delivered stimulation). Neuronal activity was monitored either at receptor neuron level using electroantennography or in the first olfactory neuropile, the antennal lobes, using calcium imaging. We tested 3 odors of different volatility: C. floridanus' highly volatile alarm pheromone undecane, its low-volatile trail pheromone nerolic acid, and an even less volatile, behaviorally active C23 alkene, cis-9-tricosene. For low-volatile odors, dummy-delivered stimulation was particularly efficient. We conclude that dummy-delivered stimulation is advantageous compared to the commonly used air-delivered stimulation when studying an animal's detection and processing of low-volatile odors.

  18. Estimating shoulder injury risk using low rate lateral impacts to dummies.

    Thor, Craig P; Bieryla, Kathleen; Gabler, Hampton C


    This paper is an investigation of low rate loading of the shoulder. The paper first presents a review of the literature on the impact tolerance of the shoulder in high and low rate loading conditions. Currently, there are no injury criteria, nor biofidelic anthropomorphic test dummies for these low rate scenarios. This study investigates dummy loading situations that are known to be non-injurious using both the 5th percentile female and 50th percentile male Hybrid III ATDs. Correlating the non-injurious loading conditions outlined in the literature with ATD tests provides a methodology for relating dummy impact forces as they pertain to human lateral shoulder impact loads. The differences in the human shoulder response and the dummy shoulder response will be resolved through the relationships established with similar loading methods. The ATD tests are compared to a previous testing methodology, resulting in a relationship between non-injurious shoulder loads of the human and the corresponding impact loads of the ATD.

  19. Enhanced FAA-hybrid III numerical dummy model in Madymo for aircraft occupant safety assessment

    Boucher, H.; Waagmeester, C.D.


    To improve survivability and to minimize the risk of injury to occupants in helicopter crash events, a complete Cabin Safety System concept including safety features and an enhanced FAA-Hybrid III dummy were developed within the HeliSafe project. A numerical tool was also created and validated to al

  20. Dummy Auxiliaries in the Second Language Acquisition of Moroccan Learners of Dutch: Form and Function

    van de Craats, Ineke; van Hout, Roeland


    This study examines an interlanguage in which Moroccan learners of Dutch use non-thematic verbs in combination with thematic verbs that can be inflected as well. These non-thematic verbs are real dummy auxiliaries because they are deprived of semantic content and primarily have a syntactic function. Whereas in earlier second language (L2) research…

  1. The influence of silver content on structure and properties of Sn–Bi–Ag solder and Cu/solder/Cu joints

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


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

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

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


    In order to solve tiny defect detection for solder balls in high-density flip-chip, this paper proposed feasibility study on the effect of detectability as well as classification based on eddy current pulsed thermography (ECPT). Specifically, numerical analysis of 3D finite element inductive heat model is generated to investigate disturbance on the temperature field for different kind of defects such as cracks, voids, etc. The temperature variation between defective and non-defective solder balls is monitored for defects identification and classification. Finally, experimental study is carried on the diameter 1mm tiny solder balls by using ECPT and verify the efficacy of the technique. PMID:26473871

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


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

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

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


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

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

    Xiuyun Zhou


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

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

    王莉; 王国忠; 方洪渊; 钱乙余


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

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

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


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

  8. Eddy current quality control of soldered current-carrying busbar splices of superconducting magnets

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


    The eddy current technique associated with a U-shaped transducer is studied for the quality control of soldered joints between superconducting busbars ('splices'). Two other quality control techniques, based on X-rays and direct measurement of the electrical resistance, are also studied for comparison. A comparative analysis of the advantages and disadvantages of these three methods in relation to the quality control of soldered superconducting busbar cables enclosed in copper shells is used for benchmarking. The results of inspections with the U-shaped eddy current transducer carried out on several sample joints presenting different types of soldering defects show the potential of this type of nondestructive (ND) quality control technique.

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

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


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

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

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


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

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

    Koo, Ja-Myeong


    Interfacial reactions and shear properties of the In-48Sn (in wt.%) ball grid array (BGA) solder joints after bonding were investigated with four different surface finishes of the substrate over an underlying Cu pad: electroplated Ni/Au (hereafter E-NG), electroless Ni/immersion Au (hereafter ENIG), immersion Ag (hereafter I-Ag) and organic solderability preservative (hereafter OSP). During bonding, continuous AuIn2, Ni3(Sn,In)4 and Cu6(Sn,In)5 intermetallic compound (IMC) layers were formed at the solder/E-NG, solder/ENIG and solder/OSP interface, respectively. The interfacial reactions between the solder and I-Ag substrate during bonding resulted in the formation of Cu6(Sn,In)5 and Cu(Sn,In)2 IMCs with a minor Ag element. The In-48Sn/I-Ag solder joint showed the best shear properties among the four solder joints after bonding, whereas the solder/ENIG solder joint exhibited the weakest mechanical integrity.

  12. Electromigration Reliability and Morphologies of Cu Pillar Flip-Chip Solder Joints with Cu Substrate Pad Metallization

    Lai, Yi-Shao; Chiu, Ying-Ta; Chen, Jiunn


    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.

  13. Abnormal growth of Ag3Sn intermetallic compounds in Sn-Ag lead-free solder

    SHEN Jun; LIU Yongchang; GAO Houxiu


    The abnormal growth of Ag3Sn intermetallic compounds in eutectic Sn-3.5% Ag solder was investigated through high-temperature aging treatment. Microstructural evolutions of this solder before and after the aging treatment were observed by optical microscopy and scanning electron microscopy. Precise differential thermal analysis was made to study the changes in enthalpies of the solder under different conditions. The results reveal that the water-cooled solder is in metastable thermodynamic state due to the high free energy of Ag3Sn nanoparticles, which sporadically distribute in the matrix as second-phase. The second-phase Ag3Sn nanoparticles aggregate rapidly and grow to form bulk intermetallic compounds due to the migration of grain boundary between primary Sn-rich phase and the Ag3Sn nanoparticles during high temperature aging treatment.

  14. Modeling of high temperature- and diffusion-controlled die soldering in aluminum high pressure die casting

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


    Soldering of cast alloys to the dies has been a continuing source of die surface damage in the aluminum die-casting industry. To reduce the repair and maintenance costs, an approach to modeling the damage and predicting the die lifetime is required. The aim of the present study is the estimation...... of the die lifetime based on a quantitative analysis of die soldering in the framework of the numerical simulations of the die-casting process. Full 3D simulations of the process, including the filling. solidification, and the die cooling, are carried out using the casting simulation software MAGMAsoft....... The resulting transient temperature fields on the die surface and in the casting are then post-processed to estimate the die soldering. The present work deals only with the metallurgical/chemical kind of soldering which occurs at high temperatures and involves formation and growth of intermetallic layers...

  15. Climate specific thermomechanical fatigue of flat plate photovoltaic module solder joints

    Bosco, Nick; Silverman, Timothy J.; Kurtz, Sarah


    FEM simulations of PbSn solder fatigue damage are used to evaluate seven cities that represent a variety of climatic zones. It is shown that the rate of solder fatigue damage is not ranked with the cities' climate designations. For an accurate ranking, the mean maximum daily temperature, daily temperature change and a characteristic of clouding events are all required. A physics-based empirical equation is presented that accurately calculates solder fatigue damage according to these three factors. An FEM comparison of solder damage accumulated through service and thermal cycling demonstrates the number of cycles required for an equivalent exposure. For an equivalent 25-year exposure, the number of thermal cycles (-40 degrees C to 85 degrees C) required ranged from roughly 100 to 630 for the cities examined. It is demonstrated that increasing the maximum cycle temperature may significantly reduce the number of thermal cycles required for an equivalent exposure.

  16. Thermal analysis of selected tin-based lead-free solder alloys

    Palcut, Marián; Sopoušek, J.; Trnková, L.


    The Sn-Ag-Cu alloys have favourable solderability and wetting properties and are, therefore, being considered as potential lead-free solder materials. In the present study, tin-based Sn-Ag-Cu and Sn-Ag-Cu-Bi alloys were studied in detail by a differential scanning calorimetry (DSC) and thermodyna......The Sn-Ag-Cu alloys have favourable solderability and wetting properties and are, therefore, being considered as potential lead-free solder materials. In the present study, tin-based Sn-Ag-Cu and Sn-Ag-Cu-Bi alloys were studied in detail by a differential scanning calorimetry (DSC...... was simulated using the Thermo-Calc software package. This approach enabled us to obtain the enthalpy of cooling for each alloy and to compare its temperature derivative with the experimental DSC curves....

  17. Shear Deformation Behaviors of Sn3.5Ag Lead-free Solder Samples

    Jing Han; Hongtao Chen; Mingyu Li; Chunqing Wang


    In this study,shear tests have been performed on the as-reflowed Sn3.5Ag solder bumps and joints to investigate the deformation behavior of Sn3.5Ag lead-free solder samples.Scanning electron microscopy (SEM) was employed to characterize the microstructures of the samples and orientation imaging microscopy (OIM) with electron backscattered diffraction (EBSD) in SEM was used to obtain crystallographic orientation of grains to provide a detailed characterization of the deformation behavior in Sn3.5Ag solder samples after shear tests.The deformation behavior in solder samples under shear stress was discussed.The experimental results suggest that the dynamic recrystallization could occur under shear stress at room temperature and recrystallized grains should evolve from subgrains by rotation.Compared with that of non-recrystallized and as-reflowed microstructures,the microhardness of the recrystallized microstructure decreased after shear tests.

  18. Joint Strength with Soldering of Al2O3 Ceramics After Ni-P Chemical Plating

    邹贵生; 吴爱萍; 张德库; 孟繁明; 白海林; 张永清; 黎义; 巫世杰; 顾兆旃


    Ni-P alloy was chemically plated on Al2O3 ceramics to produce uniform alloy coatings at temperatures below 70℃. Cu metal was electroplated onto the Ni-P coating to facilitate the soldering and shorten the chemical plating time. Then, the electroplated ceramic specimens were soldered with 60 wt.% Sn-40 wt.% Pb solder in active colophony. The highest shear strength was acquired after the heat treatment at 170℃ for 15 min. The joint fractures mostly propagated along the interface between the ceramics and the Ni-P coating, with some fracture in both the ceramics and the Ni-P coating near the interface and some along the interface between the Cu and Ni-P coatings. The results show that ceramic surface roughness and the chemical plating parameters influence the coating quality, and that suitable heat treatment before the soldering also improves the adhesion between the ceramics and Ni-P coatings, thus strengthening the joints.

  19. Correlation Between Sn Grain Orientation and Corrosion in Sn-Ag-Cu Solder Interconnects

    Lee, Tae-Kyu; Liu, Bo; Zhou, Bite; Bieler, Thomas; Liu, Kuo-Chuan


    The impact of a marine environment on Sn-Ag-Cu interconnect reliability is examined using salt spray exposure followed by thermal cycling. Sn-Ag-Cu solder alloy wafer-level packages, with and without pretreatment with 5% NaCl salt spray, were thermally cycled to failure. The prior salt spray reduced the characteristic lifetime of the Sn-Ag-Cu solder joints by over 43%. Although Sn-based materials show strong resistance to corrosion, the nature of localized corroded areas at critical locations in the solder joint caused significant degradation in the Sn-Ag-Cu solder joints. An important link between the corrosion path and Sn grain orientation was observed using orientation imaging microscopy (OIM). A strong correlation between the corrosion path and grain orientation was identified, indicating that the corrosion attack preferentially followed the basal plane of the Sn lattice.

  20. Influence of Asymmetrical Waveform on Low-Cycle Fatigue Life of Micro Solder Joint

    Kanda, Yoshihiko; Kariya, Yoshiharu


    The effects of waveform symmetry on the low-cycle fatigue life of the Sn-3.0Ag-0.5Cu alloy have been investigated, using micro solder joint specimens with approximately the same volume of solder as is used in actual products. Focusing on crack initiation life, fatigue tests on Sn-Ag-Cu micro solder joints using asymmetrical triangular waveforms revealed no significant reduction in fatigue life. A slight reduction in fatigue life at low strain ranges caused by an increase in the fatigue ductility exponent, which is the result of a weakening microstructure due to loads applied at high temperature for long testing time, was observed. This was due to the fact that grain boundary damage, which has been reported in large-size specimens subjected to asymmetrical triangular waveforms, does not occur in Sn-Ag-Cu micro size solder joints with only a small number of crystal grain boundaries.

  1. Long-Term Effects of Soldering By-Products on Nickel-Coated Copper Wire

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


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

  2. Evaluation of Detachable Ga-Based Solder Contacts for Thermoelectric Materials

    Kolb, H.; Sottong, R.; Dasgupta, T.; Mueller, E.; de Boor, J.


    Low electrical and thermal contact resistances are a prerequisite for highly efficient thermoelectric generators. Likewise, certain measurement setups for characterization of thermoelectric materials rely on good-quality contacts between sample and setup. Detachable contacts are an interesting alternative to permanent contacting solutions due to ease of handling and nondestructive disassembly of valuable samples. Therefore, the applicability of gallium-based liquid metal solder as detachable contact material was studied, particularly with regard to compatibility of the solder with state-of-the-art thermoelectric materials CoSb3, Mg2Si, and FeSi2. Tungsten, nickel, chromium, and titanium were tested as protective coatings between the thermoelectric material and liquid metal solder. Electrical measurements showed that some materials form excellent and stable contacts with the solder for a limited temperature range. At higher temperatures, application of a protective layer was found to be necessary for all investigated materials. Tungsten and nickel showed promising results as protective layer.

  3. Nano ZrO2 Particulate-reinforced Lead-Free Solder Composite

    Jun SHEN; Yongchang LIU; Dongjiang WANG; Houxiu GAO


    A lead-free solder composite was prepared by adding ZrO2 nanopowders in eutectic Sn-Ag alloy. Microstructural features and microhardness properties of those solders with different ZrO2 nanopowder fraction were examined. Results indicate that the addition of ZrO2 nanopowders reduced the size ofβ-Sn grains and restrained the formation of bulk Ag3Sn intermetallic compounds (IMCs) due to the adsorption effect of the ZrO2 particles. The Vicker's hardness of the obtained lead-free solder composites fits well with the Hall-Petch relationship. The refinement of β-Sn grains favors to improve the microhardness of composite solders.

  4. Microstructurally based thermomechanical fatigue lifetime model of solder joints for electronic applications

    Frear, D.R.; Rashid, M.M.; Burchett, S.N.


    We present a new methodology for predicting the fatigue life of solder joints for electronics applications. This approach involves integration of experimental and computational techniques. The first stage involves correlating the manufacturing and processing parameters with the starting microstructure of the solder joint. The second stage involves a series of experiments that characterize the evolution of the microstructure during thermal cycling. The third stage consists of a computer modeling and simulation effort that utilizes the starting microstructure and experimental data to produce a reliability prediction of the solder joint. This approach is an improvement over current methodologies because it incorporates the microstructure and properties of the solder directly into the model and allows these properties to evolve as the microstructure changes during fatigue.

  5. Interfacial Reactions and Joint Strengths of Sn- xZn Solders with Immersion Ag UBM

    Jee, Y. K.; Yu, Jin


    The solder joint microstructures of immersion Ag with Sn- xZn ( x = 0 wt.%, 1 wt.%, 5 wt.%, and 9 wt.%) solders were analyzed and correlated with their drop impact reliability. Addition of 1 wt.% Zn to Sn did not change the interface microstructure and was only marginally effective. In comparison, the addition of 5 wt.% or 9 wt.% Zn formed layers of AgZn3/Ag5Zn8 at the solder joint interface, which increased drop reliability significantly. Under extensive aging, Ag-Zn intermetallic compounds (IMCs) transformed into Cu5Zn8 and Ag3Sn, and the drop impact resistance at the solder joints deteriorated up to a point. The beneficial role of Zn on immersion Ag pads was ascribed to the formation of Ag-Zn IMC layers, which were fairly resistant to the drop impact, and to the suppression of the brittle Cu6Sn5 phase at the joint interface.

  6. Studies of intermetallic growth in Cu-solder systems and wettability at solid-liquid interfaces

    Martin, Raymond W.


    Approved for public release; distribution is unlimited The metallurgical bond formed between tin-lead solder and the copper substrate is characterized by the formation of an intermetallic compound layer. The growth of the intermetallic layer is the result of competing mechanisms, growth of the intermetallic at the intermetallic/copper interface and its dissolution at the intermetallic/liquid solder interface. These were studied by determining the dissolution rates of the copper and the i...

  7. Joint Lead-Free Solder Test Program for High Reliability Military and Space Applications

    Brown, Christina


    Current and future space and defense systems face potential risks from the continued use of tin-lead solder, including: compliance with current environmental regulations, concerns about potential environmental legislation banning lead-containing products, reduced mission readiness, and component obsolescence with lead surface finishes. For example, the United States Environmental Protection Agency (USEPA) has lowered the Toxic Chemical Release reporting threshold for lead to 100 pounds. Overseas, the Waste Electrical and Electronic Equipment (WEEE) and the Restriction on Hazardous Substances (RoHS) Dicctives in Europe and similar mandates in Japan have instilled concern that a legislative body will prohibit the use of lead in aerospace/military electronics soldering. Any potential banning of lead compounds could reduce the supplier base and adversely affect the readiness of missions led by the National Aeronautics and Space Administration (NASA) and the U.S. Department of Defense (DoD). Before considering lead-free electronics for system upgrades or future designs, however, it is important for the DoD and NASA to know whether lead-free solders can meet their systems' requirements. No single lead-free solder is likely to qualify for all defense and space applications. Therefore, it is important to validate alternative solders for discrete applications. As a result of the need for comprehensive test data on the reliability of lead-free solders, a partnership was formed between the DoD, NASA, and several original equipment manufactures (OEMs) to conduct solder-joint reliability (laboratory) testing of three lead-free solder alloys on newly manufactured and reworked circuit cards to generate performance data for high-reliability (IPC Class 3) applications.

  8. Thermomechanical cycling investigation of CU particulate and NITI reinforced lead-free solder

    Horton, W. Scott.


    In todayâ s Flip Chip (FC) and Ball Grid Array (BGA) electronic packages solder joints provide both the electrical as well as the mechanical connections between the silicon chip and the substrate. Due to coefficient of thermal expansion (CTE) differences between the chip and substrate the solder joints undergo thermomechanical stresses and strains as an electronic package is heated and cooled with power on/off cycles. Advances in chip designs result in chips that are larger, run hotter and d...

  9. Effects of voids on thermal-mechanical reliability of lead-free solder joints

    Benabou Lahouari


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

  10. Abdominal Twin Pressure Sensors for the assessment of abdominal injuries in Q dummies: in-dummy evaluation and performance in accident reconstructions.

    Beillas, Philippe; Alonzo, François; Chevalier, Marie-Christine; Lesire, Philippe; Leopold, Franck; Trosseille, Xavier; Johannsen, Heiko


    The Abdominal Pressure Twin Sensors (APTS) for Q3 and Q6 dummies are composed of soft polyurethane bladders filled with fluid and equipped with pressure sensors. Implanted within the abdominal insert of child dummies, they can be used to detect abdominal loading due to the belt during frontal collisions. In the present study - which is part of the EC funded CASPER project - two versions of APTS (V1 and V2) were evaluated in abdominal belt compression tests, torso flexion test (V1 only) and two series of sled tests with degraded restraint conditions. The results suggest that the two versions have similar responses, and that the pressure sensitivity to torso flexion is limited. The APTS ability to detect abdominal loading in sled tests was also confirmed, with peak pressures typically below 1 bar when the belt loaded only the pelvis and the thorax (appropriate restraint) and values above that level when the abdomen was loaded directly (inappropriate restraint). Then, accident reconstructions performed as part of CASPER and previous EC funded projects were reanalyzed. Selected data from 19 dummies (12 Q6 and 7 Q3) were used to plot injury risk curves. Maximum pressure, maximum pressure rate and their product were all found to be injury predictors. Maximum pressure levels for a 50% risk of AIS3+ were consistent with the levels separating appropriate and inappropriate restraint in the sled tests (e.g. 50% risk of AIS3+ at 1.09 bar for pressure filtered CFC180). Further work is needed to refine the scaling techniques between ages and confirm the risk curves.

  11. Packaging of hard solder 500W QCW diode laser array

    Li, Xiaoning; Wang, Jingwei; Hou, Dong; Nie, Zhiqiang; Liu, Xingsheng


    The package structure critically influences the major characteristics of diode laser, such as thermal behavior, output power, wavelength and smile effect. In this work, a novel micro channel cooler (MCC) for stack array laser with good heat dissipation capability and high reliability is presented. Numerical simulations of thermal management with different MCC structure are conducted and analyzed. Based on this new MCC packaging structure, a series of QCW 500W high power laser arrays with hard solder packaging technology has been fabricated. The performances of the laser arrays are characterized. A narrow spectrum of 3.12 nm and an excellent smile value are obtained. The lifetime of the laser array is more than 1.38×109 shots and still ongoing.

  12. Modeling of thermal processes in waveguide tracts induction soldering

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


    The problem solving of the induction heating models development, which describe the heating of the separate structural assembly components of the waveguide path and product generally, is presented in this paper. Proposed mathematical models are based on the thermodynamics equation and on the heat balance law. The system of the heating process mathematical models, such as surge tube and flange heating, and the mathematical model of the energy distribution are presented. During the modeling process with Matlab system by using mathematical models graphs of the tube, flange and coupling heating were obtained. These design charts are confirmed by the results of the experimental study. During the experimental studies pyrometers for temperature control and a video camera for visual control of the process parameters were used. On the basis of obtained models the induction soldering process features analysis is carried out and the need of its automation by the using of the information control systems for thermal management between the connection elements is revealed.

  13. Evaluation of low-residue soldering for military and commercial applications: A report from the Low-Residue Soldering Task Force

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


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

  14. Properties and Microstructures of Sn-Ag-Cu-X Lead-Free Solder Joints in Electronic Packaging

    Lei Sun


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

  15. Soldering in a Reduced Gravity Environment (SoRGE)

    Easton, John W.; Struk, Peter M.


    Future long-duration human exploration missions will be challenged by constraints on mass and volume allocations available for spare parts. Addressing this challenge will be critical to the success of these missions. As a result, it is necessary to consider new approaches to spacecraft maintenance and repair that reduce the need for large replacement components. Currently, crew members on the International Space Station (ISS) recover from faults by removing and replacing, using backup systems, or living without the function of Orbital Replacement Units (ORUs). These ORUs are returned to a depot where the root cause of the failure is determined and the ORU is repaired. The crew has some limited repair capability with the Modulation/DeModulation (MDM) ORU, where circuit cards are removed and replace in faulty units. The next step to reducing the size of the items being replaced would be to implement component-level repair. This mode of repair has been implemented by the U.S. Navy in an operational environment and is now part of their standard approach for maintenance. It is appropriate to consider whether this approach can be adapted for future spaceflight operations. To this end, the Soldering in a Reduced Gravity Environment (SoRGE) experiment studied the effect of gravity on the formation of solder joints on electronic circuit boards. This document describes the SoRGE experiment, the analysis methods, and results to date. This document will also contain comments from the crew regarding their experience conducting the SoRGE experiment as well as recommendations for future improvements. Finally, this document will discuss the plans for the SoRGE samples which remain on ISS.

  16. Solder-Filling of a Cicc Cable for the Efda Dipole Magnet

    Bauer, P.; Bruzzone, P.; Cau, F.; Weiss, K.; Portone, A.; Salpietro, E.; Vogel, M.; Vostner, A.


    Several prototype Cable-In-Conduit-Conductors (CICC) for the superconducting EDIPO (Efda DIPOle) revealed a degradation of their critical current (Ic) increasing with each loading cycle. The strong Lorentz-forces during operation in combination with the limited support of the single strands against these forces are thought to be the cause of the permanent degradation of the brittle Nb3Sn superconductor from which the multi-stranded CICC are made. In summer 2006 EFDA started to explore the possibility to remedy the Ic degradation by solder-filling the conductor in order to mechanically stabilize the twisted-strand cable inside the conduit. This solution was not considered as the main one, but as an emergency solution to be applied to the completed magnet, should every other option fail. The solder-filling approach was previously applied with success in some cases. Some issues, however, needed to be clarified before this solution could be proposed for the EDIPO project. The most important among them are the choice of solder material, details of the solder filling process, and the thermo-mechanical implications of a solder-filled, high-field, high-current cable. This work, being reported here, made use not only of simulation but also of experiments, such as the mechanical testing of solder filled cables at cryogenic temperatures.

  17. Preliminary Study on Synthesis of Organolead Halide with Lead Derived from Solder Wire

    Pratiwi, P.; Rahmi, G. N.; Aimon, A. H.; Iskandar, F.; Abdullah, M.; Nuryadin, B. W.


    Organolead halide has attracted great attention for application in perovskite solar cells due to its high power conversion efficiency (PCE) of up to 20.1%. One of the most common perovskite materials is lead based reagent. In this research, we have synthesized organolead halide with lead extracted from solder wire. In the preparation procedure, first PbCl2 and PbI2 are produced by reacting lead from the solder wire with NaCl and KI, which are used as the basic substance for the perovskite material. Then, in order to get perovskite solution, the powders are reacted with methylamine iodide (MAI) in dimethylformamide (DMF) using a solution based method. Further, the spin coating method is used to fabricate perovskite thin film. The XRD peak results agreed with JCPDS Powder Diffraction of PbCl2 and PbI2. Based on FTIR, the transmittance spectra of the organolead mixed halide that was prepared using solder wire lead exhibited absorption peaks identical to organolead mixed halide using commercial lead. The UV-Vis absorbance spectra of the organolead mixed halide from solder wire lead also exhibited the same absorption ability as from commercial lead. Morever, EDS measurement showed that the element composition of the perovskite thin film using lead from solder wire identical to that from commercial lead. This indicates that solder wire lead is suitable enough for organolead halide material synthesis.

  18. Effect of Cu concentration on morphology of Sn-Ag-Cu solders by mechanical alloying

    Kao, Szu-Tsung; Duh, Jenq-Gong


    The mechanical alloying (MA) process is considered an alternative approach to produce solder materials. In this study, the effect of Cu concentration in the ternary Sn-3.5Ag-xCu (x=0.2, 0.7, and 1) solder by MA was investigated. The (Cu,Sn) solid solution was precipitated as the Cu6Sn5 intermetallic compound (IMC), which was distributed nonuniformly through the microstructure. The Cu6Sn5 IMC, which was present in the SnAgCu solder with high Cu composition, causes the as-milled MA particle to fracture to a smaller size. Appreciable distinction on morphology of as-milled MA powders with different Cu content was revealed. When the Cu concentration was low (x=0.2), MA particle aggregated to a spherical ingot with large particle size. For higher Cu concentration (x=0.7 and x=1), the MA particle turned to flakes with smaller particle size. The distinction of the milling mechanism of Sn-3.5Ag-xCu (x=0.2, 0.7, and 1) solder by the MA process was discussed. An effective approach was developed to reduce the particle size of the SnAgCu solder from 1 mm down to 10-100 µm by doping the Cu6Sn5 nanoparticle during the MA process. In addition, the differential scanning calorimetry (DSC) results also ensure the compatibility to apply the solder material for the reflow process.

  19. Development of high strength Sn-Mg solder alloys with reasonable ductility

    Alam, Md Ershadul; Gupta, Manoj


    This study discussed the development of a series of new lead-free Sn-Mg solders by incorporating varying amounts of Mg (0.8, 1.5 and 2.5 wt. %) into pure Sn using disintegrated melt deposition technique followed by room temperature extrusion. All extruded Sn and Sn-Mg solder samples were characterized. Microstructural characterization studies revealed equiaxed grain morphology, minimal porosity and relatively uniform distribution of secondary phase. Better coefficient of thermal expansion was observed for Sn-2.5Mg sample when compared to conventional Sn-37Pb solder. Melting temperature of Sn-1.5Mg was found to be 212°C which is much lower than the conventional Sn-Ag-Cu or Sn-Cu (227°C) solders. Microhardness was increased with increasing amount of Mg in pure Sn. Room temperature tensile test results revealed that newly developed Sn-Mg solders exhibit enhanced strengths (0.2% yield strength and ultimate tensile strength) with comparable (if not better) ductility when compared to other commercially available and widely used Sn-based solder alloys.

  20. Numerical simulation of soldered joints and reliability analysis of PLCC components with J-shape leads

    Zhang Liang; Xue Songbai; Lu Fangyan; Han Zongjie; Wang Jianxin


    This paper deals with a study on SnPb and lead-free soldered joint reliability of PLCC devices with different lead counts under three kinds of temperature cycle profiles, which is based on non-linear finite element method. By analyzing the stress of soldered joints, it is found that the largest stress is at the area between the soldered joints and the leads, and analysis results indicate that the von Mises stress at the location slightly increases with the increase of lead counts. For PLCC with 84 leads the soldered joints was modeled for three typical loading (273-398 K, 218-398 K and 198-398 K) in order to study the influence of acceleration factors on the reliability of soldered joints. And the estimation of equivalent plastic strain of three different lead-free solder alloys (Sn3.8Ag0.7Cu, Sn3.5Ag and Sn37Pb) was also carried out.