无铅材料SnAgCu的Anand参数测定和CSP焊点寿命预测

DETERMINATION OF ANAND PARAMETES FOR Pb-FREE MATERIAL SnAgCu AND LIFE PREDICTION FOR A CSP STRUCTURE

摘要: 在不同的温度和常应变率条件下，对无铅焊料95.7Sn3.8Ag0.5Cu进行不同的温度和应变率条件下的拉伸试验，采用非线性数据拟合方法，得到材料的Anand本构模型参数。基于三维有限元分析方法预测热循环条件下焊点的疲劳寿命，对无铅材料95.7Sn3.8Ag0.5Cu和含铅材料62Sn36Pb2Ag的CSP焊点寿命进行了预测和比较，结果表明无铅材料95.7Sn3.8Ag0.5Cu的疲劳寿命比含铅材料62Sn36Pb2Ag的寿命高30.93%。

Abstract: A series of tensile tests for Pb-free solder material 95.7Sn3.8Ag0.5Cu have been conducted under a wide range of temperatures and constant strain rates. A procedure for the determination of Anand material parameters through data fitting is proposed to find nine constants. Three-dimensional finite element analysis has been applied to predict the fatigue life of solder joints under thermal cycling conditions. Finally the life of CSP solder joint based on Pb-free material 95.7Sn3.8Ag0.5Cu and that based on standard Pb material 62Sn36Pb2Ag are predicted and compared. It can be found that the fatigue life based on 95.7Sn3.8Ag0.5Cu is 30.93% longer than that based on 62Sn36Pb2Ag.