The Solder Life Prediction Model of Power Module under Thermal Cycling Test (TCT)

Solder as an interconnection material is widely used in power semiconductor device. The solder reliability is a challenge in higher temperature operation. This paper provides a preliminary solder life prediction model based on thermo-mechanical finite element method (FEM) with material's creep characteristics. To construct the life model, not only simulation but also experiment are necessary to be executed. In the experiment stage, the solder crack would be observed by Scanning Acoustic Microscope (SAM) [1], which help us calculate the life cycle when initial crack occurred and the crack propagation rate. In simulation stage, simulation would be implemented by ANSYS and creep material properties would be used. In this paper, the Garofalo-Arrhenius creep equation as a steady state creep model was used to express the solder alloys, and the solder's strain value would be got from simulation results. The solder life model can be constructed by Dzrveaux semi-empirical life prediction formula.