Transient Electro-Thermo-Mechanical Coupled Analysis of SiC MOSFET by Face-based Smoothed Finite Element Method

With the rising power density of wide-bandgap power electronics, mechanical failures induced by coupled electrical and thermal effects become increasingly pronounced. To achieve accurate temperature and stress predictions for the reliability-driven design of power electronic devices, this paper presents a novel and efficient algorithm for transient electro-thermo-mechanical modelling methodology, which is developed by extending the face-based smoothed finite element method (FS-FEM) to multi-field coupling problems. By adopting the classical multi-field coupling theory and deriving the transformation between nodal values and smoothing-domain values, we successfully establish the coupling theory within the FS-FEM framework. Furthermore, the validity of the proposed approach is verified through coupled electro-thermo-mechanical simulations of a SiC MOSFET model. Results demonstrate that, when using identical tetrahedral meshes, the FS-FEM exhibits higher computational accuracy, faster convergence rate, and greater computational efficiency compared to the standard Finite Element Method (FEM). This study provides a powerful tool for coupled electro-thermo-mechanical analysis of power electronics and micro-electronics.