热循环条件下高密度互连点的应力应变分析  

Analysis of stress-strain in high density interconnection joints under thermal cycle

作　　者：朱红瑜[1] 尚拴军 苏鹏 韩诗男 赵亚涛 Zhu Hongyu;Shang Shuanjun;Su Peng;Han Shinan;Zhao Yatao(School of Mechanic&Electrical Engineering,Henan University of Technology,Zhengzhou 450001,China)

机构地区：[1]河南工业大学机电工程学院,郑州450001

出　　处：《焊接》2018年第10期5-8,65,共5页Welding & Joining

基　　金：国家自然科学基金(U1504507);河南省科技厅国际合作项目(172102410025)

摘　　要：采用多线性随动强化材料模型和粘塑性材料模型,模拟填充胶和无铅钎料的材料性质,建立高密度倒装芯片封装的有限元模型;基于热循环条件下封装体中互连点的应力应变分析,探讨其可靠性,通过试验对分析结果进行验证。结果表明,封装体中边角焊点承受最高的等效应力,为最易失效焊点;以最易失效焊点为代表,最大塑性剪切应变分布在该焊点的芯片侧,呈现出由外侧向内侧减小的分布特征,表明裂纹倾向于在外侧形成,向内侧扩展,试验结果验证了这一分析。此外,文中通过对塑性应变演变规律的分析,探讨了互连点的失效机理。A finite element model of high density flip chip packages was developed,in which multi-linear kinematic hardening material model and viscoplastic material model were used to describe the material behavior of the underfill and Pb-free solder paste.The stress-strain of solder bump was simulated to investigate its stability and the results were validated by experimental data.The results show that,the maximum equivalent stress appears at the outmost solder bump which can be considered as the most easy to be failure solder bump.Based on this solder bump,the maximum plastic shear strain appears at the chip side and it decreases from the outside to the inside which demonstrates a crack may initiate from the edge of the solder bump and propagate to the inside.This conclusion is also validated by experimental results.Besides,the failure mechanism was investigated by analyzing the behavior of plastic strain of the solder bump corner.

关 键 词：倒装芯片封装 微焊点 无铅钎料 可靠性 

分 类 号：TG40[金属学及工艺—焊接]