High-Temperature Transient Thermal Analysis for SiC Power Modules

Transient thermal analysis is a very useful tool for thermal evaluation to realize the stable operation of SiC power modules which are operated at higher temperatures than conventional Si power modules. A transient thermal analysis system to investigate the thermal characteristics of SiC power modules at high temperature is presented. We have found that precise temperature measurement at the initial stage of the junction temperature decay curve is necessary in order to evaluate the thermal resistance and heat capacity of the die attach, since the thermal diffusivity of SiC is larger than that of Si and the temperature distribution of SiC die was considered. Using the proposed transient thermal analysis method, the thermal resistance and heat capacity of the AuGe die attach under the SiC-SBD was successfully evaluated at temperatures up to 250 °C.