将蒙特卡罗法和有限元方法用于分析球珊阵列封装(BGA封装)焊点中微孔洞缺陷对焊点应力的影响。先用X射线断层扫描方法测定焊点中孔洞大小及其分布规律, 然后利用Abaqus有限元分析软件建立BGA封装有限元模型, 采用Anand本构方程描述焊点的应力应变响应, 分析BGA封装焊点应力分布情况; 并针对关键焊点即应力最大的焊点, 建立了含孔洞大小和位置呈随机分布的焊点参数化有限元模型, 结合试验结果, 分析了孔洞直径和位置对焊点应力分布的影响。结果表明: 微孔洞直径越小, 越接近于焊点的表面, 焊点中的应力越大。

The Monte-Carlo and finite element method were applied to analysis the stress of BGA package solders affected by micro-void defects. First, the size of the micro-void and its distribution were tested by computed X-ray tomography. The finite element model of BGA package was established by Abaqus finite element analysis software, and the Anand constitutive equation was used to describe the stress and strain response of solder joints to analyze the stress distribution. Based on the critical solder joint where stress was maximum, the parametric finite element model for the solder joint with stochastic distribution of micro-void size and position was established, and then to analyz the law of solder joint stress distribution combing with experimental results. The results show that the smaller the diameter of the micro-void was and the closer the micro-void get to the surface of solder joints, the larger the stress on the solder joints could be obtained.