Thermal Fatigue of Solder Joints

在此RUI奖下提供资金，允许8个本科生团队在两年的时间内参加一个连续的研究项目，评估焊点的热机械疲劳。为了使这一经验成功，建议创造一个独特的学习经验，这是一个创新的课堂教学和研究相结合.一个硕士生将协助这个项目，并通过这样做有一个独特的硕士水平的经验，旨在要求他人的工作，他们的工作与本科生的综合评价和领导能力的发展。研究：热机械疲劳（ThermomachinicalFatigue，简称TMF）是电子组装中焊点失效的主要原因。焊点的破坏是很难建模的，因为有许多复杂的和相互作用的因素影响着焊点的破坏进程。由于高同源温度（0.8或更高），在热处理过程中发生显著的微观结构演变，随着热处理的进行，材料的性质发生变化。将进行一项实验研究，以1）确定那些更容易测量的材料特性最有可能影响抗蠕变性，2）评估用于抗蠕变试验的各种加速因子，3）评估润湿在抗蠕变失效中的作用。和2）将评估润湿在粘附中的作用。这意味着那些考虑使用无铅焊料合金的人将能够使用目前还没有的诊断“工具”--与耐腐蚀性相关的材料特性的组合。教学：为了使本科生能够参与持续的研究计划，一个独特的“课堂”体验将补充研究。这些课程将包括互动学习技术，并使本科生接触1）必要的理论背景，2）项目的状态，3）必要的实验室技术，包括统计分析，4）口头和书面沟通技巧，以及5）更广泛的问题，包括道德和经济影响。所有这些主题都将基于上下文。本课程的理念是，高水平的本科生需要在布鲁姆分类法的综合水平上进行表演，他们的经验旨在使他们能够这样做。硕士生将被要求在布鲁姆分类法的评估水平上进行表演（评估本科生的工作），并将这项工作与他们自己对润湿的研究相结合，从而参与独特的整合经验。此外，学生将培养领导能力，并可能被说服攻读博士学位，并培养教学的愿望。硕士生的经验也可能鼓励本科生攻读研究生学位。我们认为，这个全面的计划将最大限度地提高成功的机会，并作为一个示范项目，为其他人希望将研究纳入本科生的经验，并制定一个新的硕士课程。影响：人们认为，该计划可以显着影响本科教育作为一个概念的证明，在研究型课程的发展，产生终身学习的赞赏，并展示了本科研究的价值，以外部社区。这项工作补充了PI目前的工作，并为他未来的计划奠定了基础。

Funding is provided under this RUI award to permit 8 teams of undergraduatestudents over the course of a two-year period to participate in a continuousresearch project evaluating the thermomechanical fatigue of solder joints. Tomake this experience successful it is proposed to create a unique learningexperience which is a combination of innovative classroom instruction andresearch. A master's student will assist in this project, and by doing so have aunique master's level experience designed to require the evaluation of the workof others, the synthesis of their work with that of the undergraduates and thedevelopment of leadership skills. There are research and teaching components tothis proposed project.Research: Thermomechanical fatigue (TMF) is the leading cause of solder jointfailure in electronic assemblies. TMF of solder joints is difficult to model asthere are many complex and interacting factors effecting the progression ofdamage to the joint. Because of the high homologous temperatures (0.8 or higher)significant microstructural evolution occurs during TMF, changing the propertiesof the material as TMF progresses. An experimentalinvestigation will be conducted to 1) identify those more readily measured materialproperties most likely to affect TMF resistance, 2) evaluate the variousacceleration factors used in TMF testing, and 3) evaluate the role of wetting inTMF failures.As a result of this research much insight into TMF failure will be gained - 1)progress will be made toward the development of an experimentally verifiedenergy model, and 2) the role of wetting in adhesion will be assessed. Thismeans that those considering using lead-free solder alloys will be able to usediagnostic "tools" not currently available -- the combination of materialproperties which correlate to TMF resistance.Teaching: To enable undergraduates to participate in a continuing researchprogram, a unique "classroom" experience will supplement the research. Theseclass sessions will embrace interactive learning techniques, and expose theundergraduates to 1) the necessary theoretical background, 2) the status of theproject, 3) necessary lab techniques including statistical analysis, 4) oral andwritten communication skills, and 5) broader issues including ethics andeconomic impact. All of these subjects will be context based. The philosophy ofthis course is that upper level undergraduates need to perform at the synthesislevel of Bloom's Taxonomy, and their experience is designed to enable them to doso.The master's student will be required to perform at the evaluation level ofBloom's Taxonomy (evaluating the work of the undergraduates) and synthesize thiswork with their own study on wetting, thus participating in a unique integratingexperience. Additionally the student will develop leadership skills, andpossibly be persuaded to pursue a doctoral degree and develop a desire to teach.The master's students experience may also encourage the undergraduates to pursuea graduate degree.It is felt that this comprehensive plan will maximize the chances for successand serve as a demonstration project for others desiring to incorporate researchinto the undergraduate experience and developing a novel masters program.Impact: It is felt that this program can significantly impact undergraduateeducation by serving as a proof of concept in the development of researchoriented courses, generating an appreciation of life-long learning, anddemonstrating the value of undergraduate research to the outside community. Thiswork complements the current work of the PI and lays the foundation for hisfuture plans.