3D Thermal-Fluid and Stress Analysis for Single Chip SiC Power Sub-Modules

A three dimensional thermal-fluid and stress model of a single chip SiC power sub-module was generated using ANSYS in order to determine the maximum temperature and deformation under various conditions. The effects of heat flux, working fluid temperature and differential pressure on temperature and thermal stress contours were of particular concern. Steady state analysis with water as the working fluid, a simulated heat flux of 11.12×104 W/m2, an interface coupling film coefficient of either 30 or 200 W/m2-K between the cooling plate and fluid, and ambient film coefficients from 6 W/m2-K to 300 W/m2-K, predicts maximum device junction temperatures between 374 and 316 K, and corresponding deformations from .0351% to .0293%. Under the same boundary and loading conditions, but with air as the working fluid, the deformations reached .0405% to .0296%, with temperatures between 427 and 316 K. Transient analysis also showed junction temperatures in the predicted range and determined the time to reach steady state to be between 150 and 2500 seconds depending on the boundary conditions. Experiments were conducted in order to validate ANSYS results.