Thermal Fatigue of Solder Joints

该奖项提供资金，允许8个本科生团队在为期两年的时间内参与一项评估焊点热机械疲劳的持续研究项目。为了使这一体验取得成功，建议创造一种独特的学习体验，这是创新课堂教学和研究的结合。硕士研究生将协助这个项目，通过这样做，拥有独特的硕士水平的经验，旨在要求对其他人的工作进行评估，将他们的工作与本科生的工作相结合，并发展领导技能。研究：热机械疲劳(TMF)是电子组件中焊点失效的主要原因。焊点的TMF很难建模，因为有许多复杂的交互因素影响着焊点的损伤发展。由于相对应温度较高(0.8或更高)，在TMF过程中发生了显著的组织演变，随着TMF的进行，材料的性能发生了变化。将进行一项实验研究，以1)确定那些更容易测量的最有可能影响TMF阻力的材料性能，2)评估TMF测试中使用的各种加速因子，以及3)评估润湿在TMF故障中的作用。作为这项研究的结果，将获得对TMF故障的更多洞察-1)将在开发实验验证的能量模型方面取得进展，2)将评估润湿在附着力中的作用。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TMF电阻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，独特的“课堂”体验将作为研究的补充。这些课程将包含互动学习技术，并让本科生接触到1)必要的理论背景，2)项目的现状，3)必要的实验室技术，包括统计分析，4)口头和书面交流技能，以及5)更广泛的问题，包括伦理和经济影响。所有这些主题都将基于上下文。这门课程的理念是，高水平的本科生需要在布鲁姆分类学的综合水平上表现，他们的经验是为了使他们能够做到这一点。硕士学生将被要求在布鲁姆分类学的评估水平上表现(评估本科生的工作)，并将这项工作与他们自己的润湿研究相结合，从而参与到一种独特的综合体验中。此外，学生还将发展领导能力，并可能被说服攻读博士学位并培养从教的愿望。硕士学生的经历也可能鼓励本科生攻读研究生学位。人们认为，这一综合计划将最大限度地增加成功的机会，并为其他希望将研究纳入本科生经验并开发新的硕士课程的人提供示范项目。影响：人们认为，该项目可以显著影响本科生教育，因为它可以作为研究型课程发展的概念证明，产生对终身学习的欣赏，并向外部社会展示本科生研究的价值。这项工作是对国际和平协会目前工作的补充，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.