Effect of Temperature Shock Testing Profile SiC Power Module Reliability

In this paper, silicon carbide (SiC) power module temperature shock reliability was evaluated by finite element method. In addition to one of the most acknowledged testing standards, i.e., AQG324, several testing conditions were simulated by varying the soaking time at both high and low temperature extremes to quantify the effects of soaking time on the solder die-attachment reliability. Thermal fatigue lifetime of the lead-free solder, SAC305, was calculated by the modified Coffin-Manson equation. Although the testing profile with shortened soaking time caused relatively low shear plastic strain for each temperature cycle, it allowed a large number of cycles that could be accumulated within a certain period, hence to significantly reduce the overall testing time. Simulation results showed that, regardless of die size, the total time to fail could be effectively shortened by 40% to 50% by reducing the soaking time from 15min to 5min.