考虑晶粒结构的无铅焊点电迁移失效分析  

Electromigration failure analysis for lead-free solder joint considering grain structure

作　　者：王静 张元祥 张继成[1] 梁利华[1] WANG Jing;ZHANG Yuanxiang;ZHANG Jicheng;LIANG Lihua(College of Mechanical Engineering,Zhejiang University of Technology,Hangzhou 310014,China;College of Mechanical Engineering,Quzhou University,Quzhou 324000,Zhejiang Province,China)

机构地区：[1]浙江工业大学机械工程学院,浙江杭州310014 [2]衢州学院机械工程学院,浙江衢州324000

出　　处：《电子元件与材料》2018年第7期14-21,28,共9页Electronic Components And Materials

基　　金：国家自然科学基金资助项目(51375447;51375448;51605252);浙江省自然科学基金资助项目(LQ13E050014)

摘　　要：针对微观晶粒结构演化、尺度效应等微观晶粒结构诱致的电迁移失效问题,本文通过有限元分析软件,考虑焊点不同晶粒结构,对SAC305无铅焊点进行电迁移失效模式分析,进一步探明焊点电迁移失效机制。通过电子背散射衍射(EBSD)对焊点晶粒结构及其取向进行测定和表征,为有限元模型提供依据。采用Bunge欧拉角(φ_1,Φ,φ_2)来表示晶体的取向。结果表明单晶粒结构焊点正则化原子浓度及其焊点失效寿命在很大程度上取决于晶体取向(特别是Φ角,即晶体c轴取向与电流方向的夹角,该角度表征了β-Sn晶粒绕c轴的旋转)。模拟结果与电迁移实验结果较为吻合,进一步验证了该有限元分析方法的可行性。In order to solve the problem of micro-grain structure evolution,scale effect and other electro-migration failures induced by microscopic grain structure,finite element analysis softw are was used to perform electromigration failure mode analysis on lead-free solder joints of SAC305,considering different grain structures of solder joints. The electromigration failure mechanism of solder joints was further confirmed. Electron backscattered diffraction（ EBSD） was used to characterize the grain structure and track orientation in solder joints,which provided the basis for the finite element model. When Bunge Euler angles（ φ1,Φ,φ2） are used to represent crystal orientation,the study result indicates that the normalized atomic density and the failure time of electromigration of single crystal bump are strongly impacted by crystal orientation especially the second Euler angle Φ,which is betw een the c axis orientation and the current direction and specifies the rotation of the c axis determines. The simulation results are in good agreement with the results of electromigration experiments,which further validates the feasibility of the finite element analysis method.

关 键 词：晶粒结构 电迁移 无铅焊料 原子密度积分法 失效分析 有限元分析 

分 类 号：O347.3[理学—固体力学] TN406[理学—力学]