GOALI: Understanding and Modeling Electromigration Induced Solder Degradation

GOALI：了解电迁移引起的焊料降解并对其进行建模

• 批准号: 1207291
• 负责人: Antoinette Maniatty
• 金额: $ 31.79万
• 依托单位: Rensselaer Polytechnic Institute
• 依托单位国家: 美国
• 项目类别: Standard Grant
• 财政年份: 2012
• 资助国家: 美国
• 起止时间: 2012-08-15 至 2016-07-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=1207291&HistoricalAwards=false
• 关键词: GOALI; Understanding; Modeling; Electromigration; Induced

TECHNICAL SUMMARY:The goals of this research are (i) to gain a better understanding of the effect of microstructure on the driving forces and resulting mass diffusion processes associated with electromigration as well as stress and temperature driven diffusion processes in tin-based solder, and (ii) to develop validated predictive simulation tools to predict the lifetime of solder connections for given microstructural parameters. Electromigration is a mass diffusion process attributed to momentum transfer from conducting electrons to diffusing metal atoms, which, over time, may lead to degradation and device failure. With the conversion to tin-based solders and the continued miniaturization of microelectonic devices, reliability has become a major concern due to the complex behavior of tin-based solder subjected to increasing current densities that drive electromigration. This work involves an integrated effort involving experimentation, modeling, and simulation. The experimental work focuses on accelerated electromigration tests on chip scale package test structures and detailed materials characterization to investigate the effect microstructure has on degradation. This effort is closely coupled with the modeling and simulation work focused on developing a model for diffusion at the grain scale, considering the electrical, mechanical, and thermal driving forces. Both anisotropic lattice and grain boundary diffusion will be included in the model, as well as crystal plasticity in the mechanical response. The model will be implemented into a parallel, finite element simulation tool, which will be validated against experiments and used to predict time to failure for representative microstructures. This work is a collaborative effort with researchers at Fairchild Semiconductor, who will lead the experimental work, be involved in the development of simulation tools, and will use the tools developed in their future package design process.NON-TECHNICAL SUMMARY:This research addresses reliability issues associated with tin-based solders in microelectronic devices that are arising as devices become smaller in order to increase chip speed while reducing cost and power consumption. Due to environmental concerns, tin-based solders have now replaced lead-based solders used in microelectronic devices. When an electrical current is carried by a very small solder bump in a modern device, a process called electromigration occurs where the solder material actually migrates from one end of the solder bump to the other, driven by the electrons flowing through the solder. This migration of material may lead to failure, which is a major source of reliability concern in tin-based solders. Electromigration may be slowed or completely arrested through careful design and manufacture of the microelectronic device. In order to do this, a better understanding of electromigration in tin-based solder, and modeling and simulation tools based on that understanding must be developed, which is the focus of this research. Researchers at Fairchild Semiconductor, a US company and global provider of semiconductor solutions, are collaborators on this research. This project will impact Fairchild and its customers by developing the knowledge needed to more accurately predict the life and reliability of wafer level packaging and will provide a critical product design tool to shorten time to market and maintain a competitive advantage in the global market. This project will also train and equip undergraduate and graduate students involved in the research in new advanced methods for physics based modeling of materials and processes, computational engineering, and conducting fundamental interdisciplinary research to address emerging research needs in material processing and design.

技术总结：本研究的目标是（i）更好地了解微结构对驱动力的影响，以及与锡基焊料中的电迁移以及应力和温度驱动的扩散过程相关的质量扩散过程，以及（ii）开发经验证的预测模拟工具，以预测给定微结构参数下的焊料连接寿命。电迁移是一种质量扩散过程，归因于从导电电子到扩散金属原子的动量转移，随着时间的推移，这可能导致退化和器件故障。 随着向锡基焊料的转换和微电子器件的持续小型化，由于锡基焊料受到驱动电迁移的增加的电流密度的复杂行为，可靠性已成为主要关注点。这项工作涉及实验、建模和仿真的综合努力。 实验工作的重点是加速电迁移测试芯片级封装测试结构和详细的材料表征，以调查微结构对退化的影响。 这一努力是密切耦合的建模和模拟工作，重点是开发一个模型，在晶粒尺度上的扩散，考虑电，机械和热驱动力。各向异性晶格和晶界扩散将包括在模型中，以及晶体塑性的机械响应。该模型将被实施到一个并行的，有限元模拟工具，这将对实验进行验证，并用于预测时间的代表性的微观结构的故障。 这项工作是一个合作的努力，研究人员在费尔柴尔德半导体，谁将领导的实验工作，参与开发的仿真工具，并将使用开发的工具，在其未来的封装设计process.NON-TECHNICAL摘要：这项研究解决了可靠性问题与锡基焊料在微电子器件中出现的设备变得更小，以提高芯片速度，同时降低成本和功耗。 由于环境问题，锡基焊料现在已经取代了微电子器件中使用的铅基焊料。当电流由现代器件中非常小的焊料凸块承载时，发生称为电迁移的过程，其中焊料材料实际上由流过焊料的电子驱动从焊料凸块的一端迁移到另一端。 材料的这种迁移可能导致失效，这是锡基焊料可靠性问题的主要来源。 通过仔细设计和制造微电子器件，可以减缓或完全阻止电迁移。 为了做到这一点，更好地了解锡基焊料中的电迁移，以及基于这种理解的建模和仿真工具必须开发，这是本研究的重点。费尔柴尔德半导体公司是一家美国公司，也是全球半导体解决方案提供商，该公司的研究人员是这项研究的合作者。该项目将通过开发更准确地预测晶圆级封装的寿命和可靠性所需的知识来影响费尔柴尔德及其客户，并将提供关键的产品设计工具，以缩短上市时间并在全球市场上保持竞争优势。该项目还将培训和装备参与研究的本科生和研究生，研究新的先进方法，用于基于物理的材料和工艺建模，计算工程，并进行基础跨学科研究，以满足材料加工和设计的新兴研究需求。