Thermal Fatigue Life Time Prediction of Sn-3.5Ag Lead-Free SolderJoint for Chip Scale Package
CSP封装Sn-3.5Ag焊点的热疲劳寿命预测

The thermal fatigue life time of Sn-3.5Ag lead-free solder joint of a chip scale package subjected to a thermal cycling load is predicted.Using the finite element analysis software ANSYS,a three dimensional symmetric model of the chip scale package is established,which uses the Anand constitutive model to describe the viscoplastic material property of Sn-3.5Ag lead-free solder joints.The deformation of the CSP package and the stress-strain variation of the solder joint under a thermal cycling load are investigated through thermal stress analysis.The Darveaux fatigue life prediction method is used to calculate the fatigue life time of the lead-free solder joint based on the finite element simulation results.