High Fidelity Package Simulation Models Capturing Accurate Thermal Cross-Coupling

3D finite element analyses of high fidelity and simplified power semiconductor package models are compared to identify essential model features. The paper investigates interaction between heat dissipating power semiconductor devices and nearby, surroundings components, an aspect challenging to implement in simulations for use during power electronic system design phases. This problematic thermal cross-coupling between components is stronger in compact power converters, having high power densities. To maximize accuracy of these heat transfer simulations, specific geometric features are used to capture the effects of such thermal interaction. This paper shows how particular care must be taken during such a component modelling process. In a presented test case, with a semiconductor switch placed on a printed circuit board, simulation results show how the temperature of a nearby ceramic capacitor is significantly raised (ΔT=+25°C) when compared to a simplified packaging model based on datasheet information alone. In another testcase, impacts of encapsulation and wire bond interconnects on thermal self-impedance of a discrete power semiconductor component are quantified with frequency response functions.