Thermal model of fully-molded, multi-chip power modules

Abstract:
The peak junction temperature of a power device determines whether or not it can be used for a certain application. Power losses and thermal characteristics are required to estimate the junction temperature because it cannot be measured directly in most cases. When several power chips are assembled onto one package, a thermal interaction occurs between the chips. The fullymolded modules are affected by the interaction much more than modules with a metal substrate. In addition to the thermal interaction, the thermal resistance becomes higher when several power chips operate simultaneously. A thermal model that considers both thermal interaction and multiple heat sources demonstrates an improved estimation of junction temperature.