柱形铜凸点在热力耦合场中的原子迁移.pdfVIP

第6卷 第8期 580 中国科技论文在线 SCIENCEPAPER ONLINE 2011 年 8 月 柱形铜凸点在热力耦合场中的原子迁移 何俐萍，邬博义，李 艳，张遒姝，黄洪钟 （电子科技大学机械电子工程学院，成都 611731 ） 摘 要：随着尺寸的进一步微型化和载荷严酷化，集成电路(integrated circuit, IC)封装焊点中的原子迁移失效问题越来 越突出。由于材料热性能和电阻率的差异而造成的温差是封装焊点所要面对的主要问题之一。针对铜柱形凸点这种新 型倒装芯片互连形式，通过热动力学理论和黏塑性力学分析，运用有限元方法研究了热场和力场耦合作用下柱形铜凸 点的热迁移和应力迁移现象。通过分析温度载荷模型下影响原子迁移的多个因素，提取了温度梯度和应力分布等关键 参数，进而得到热力耦合场作用下原子迁移的失效机制和发生条件。所建立的失效模型有助于促进IC封装方面原子迁 移的可靠性改善工作。 关键词：集成电路封装；柱形铜凸点；热力耦合；原子迁移；有限元模拟 中图分类号：TG42 ；TN4 文献标志码：A 文章编号：1673 －7180(2011)08 －0580 －5 Atomic migration of Cu-pillar bumps in thermomechanical coupling fields He Liping，Wu Boyi，Li Yan，Zhang Qiushu，Huang Hongzhong (School of Mechatronics Engineering, University of Electronic Science and Technology of China, Chengdu 611731, China) Abstract: With further miniaturization and harsh service loading, the failure problems of atomic migration for solder joints become more dominative in integrated circuit (IC) packaging. The temperature difference caused by thermal properties and electrical resistivity among different materials is a vital factor for IC package solder joints. In consideration of such a new lip-chip interconnect form as a Cu-pillar bump, thermo-migration and stress-migration of Cu-pillar bumps in thermomechanical coupling fields were investigated via the kinetic theory and viscoplastic mechanical analysis by means of finite element method. Informed of influencing factors of atomic migration, we obtained such parameters as temperature gradient and stress distribution in a specific model under temperature load, and then concluded the failure mechanism and occurrence conditions of atomic m