Solder Joint Lifetime Characterization of a SiC Power MOSFET Module Under Power Cycling

This study attempts to propose a design-for-reliability (DfR) methodology for solder joint reliability characterization of a developed 1700V/100A, 9.6 kW SiC power metal-oxide semiconductor field-effect transistor (MOSFET) module (termed the ITRI SiC power module) under power cycling, for on-board electric vehicle (EV) charging (OBC). This DfR methodology integrates a viscous computational fluid dynamics (CFD) thermal model and a thermal-mechanical finite element model (FEM). The calculated viscoplastic strain results using the proposed DfR methodology and the experimental lifetime data together with the characterized characteristic crack area are used to establish the physical failure mechanism and damage criteria-based (PFMDC) lifetime prediction model. The proposed DfR methodology is further tested on the developed ITRI SiC power module, and the validity of the proposed DfR methodology is demonstrated by comparing the predicted power cycling solder joint lifetime with the experimental results. Finally, parametric study is performed to evaluate the influence of the power cycling solder joint reliability of the ITRI SiC power module under actual application conditions.