Sn0.7Cu无铅焊点的电迁移失效模拟及优化分析  

Electromigration failure simulation and optimization analysis for Sn0.7Cu lead-free solder

作　　者：赵元虎[1] 张元祥[2] 许杨剑[1] 梁利华[1] 

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》2015年第4期59-63,共5页Electronic Components And Materials

基　　金：国家自然科学基金资助项目(No.51375447;51375448);浙江省自然科学基金资助项目(No.LQ13E050014)

摘　　要：基于ANSYS有限元软件,综合考虑电子风力、温度梯度、应力梯度和原子密度梯度四种电迁移驱动机制,采用原子密度积分法(ADI)对倒装芯片球栅阵列封装(FCBGA)的Sn0.7Cu无铅焊点进行电迁移失效模拟。针对焊点直径、焊点高度、焊点下金属层(UBM)厚度三个关键参数进行电迁移失效的正交试验优化,探究焊点尺寸对电迁移失效的影响。研究表明:焊点直径和高度的增加会缩短焊点的电迁移失效寿命(TTF),而UBM层厚度对焊点失效寿命的影响相对较小;焊点局部拉应力对焊点的失效寿命影响较大,通常会加剧焊点的空洞失效。Based on finite element software of ANSYS, the electromigration failure simulation for Sn0.7Cu solder joint of flip chip ball grid array（FCBGA） package was performed by using atomic density integral（ADI） method. The driving forces of electromigration include electron wind force, stress gradients, temperature gradients, as well as atomic density gradient. The optimal orthogonal experiment was conducted to evaluate the effect of solder diameter, solder height, under bump metal（UBM） layer thickness of solder joints on electromigration failure. The study result indicates that the increase of solder joint height and diameter can short the failure time of electromigration（TTF）, but there is little effect of UBM layer thickness on TTF of electromigration. Meanwhile, local tensile stress has significant influence on the TTF of electromigration, which usually generate more voids of solder joint.

关 键 词：Sn0.7Cu 无铅焊点 失效模拟 原子密度积分法 正交试验 电迁移 

分 类 号：O347.3[理学—固体力学] TN406[理学—力学]