Thermal Fatigue of Solder Joints

焊点的热疲劳

• 批准号: 0140605
• 负责人: Mark Palmer
• 金额: --
• 依托单位: Kettering University
• 依托单位国家: 美国
• 项目类别: Standard Grant
• 财政年份: 2002
• 资助国家: 美国
• 起止时间: 2002-07-01 至 2004-12-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=0140605&HistoricalAwards=false
• 关键词: Thermal; Fatigue; Solder; Joints

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.

该项目由8个本科生团队组成，他们将在两年的时间内参与一项评估焊点热机械疲劳的连续研究项目。为了使这一经验成功，建议创造一种独特的学习体验，这种体验是创新课堂教学和研究的结合。硕士生将协助这个项目，通过这样做，有一个独特的硕士水平的经验，要求评估他人的工作，将他们的工作与本科生的工作相结合，并发展领导技能。这个拟议的项目有研究和教学组成部分。研究：热机械疲劳（TMF）是导致电子组件焊点失效的主要原因。由于影响焊点损伤过程的因素很多且相互影响，因此焊点的TMF很难建模。由于高同源温度（0.8或更高），在TMF过程中发生了显著的微观结构演变，随着TMF的进行改变了材料的性能。将进行一项实验调查，以1)确定那些更容易测量的最可能影响TMF阻力的材料特性，2)评估在TMF测试中使用的各种加速因素，以及3)评估润湿inTMF失效的作用。由于这项研究的结果，将获得对TMF失效的许多见解- 1)将在实验验证的能量模型的开发方面取得进展，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无法获得的诊断“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一个持续的研究项目，一个独特的“课堂”体验将补充研究。这些课程将采用互动学习技术，并使本科生接触到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，包括伦理和经济影响。所有这些主题都是基于上下文的。本课程的理念是，高年级本科生需要在布鲁姆分类法的综合层面上表现，他们的经验旨在使他们能够做到这一点。硕士生将被要求在bloom 's Taxonomy（评估本科生的工作）的评价水平上进行表演，并将其与自己对润湿的研究结合起来，从而参与一次独特的整合体验。此外，学生将发展领导技能，并可能被说服去攻读博士学位，并培养教书的愿望。硕士生的经历也可以鼓励本科生攻读研究生学位。我们认为，这一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，为其他希望将研究纳入本科经验和开发一个新颖的硕士项目。影响：我们认为这个项目可以通过作为研究型课程发展的概念证明，产生终身学习的欣赏，并向外部社区展示本科研究的价值，从而对本科教育产生重大影响。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。