Structure Function Assisted Thermal Coupling Analysis for Paralleling Power Semiconductor Chips

Accurate thermal coupling analysis is not only important for semiconductor power module layout optimisation, but also indispensable for complete thermal model development and subsequent electro-thermal simulations. It is however challenging to derive the transient coupled thermal impedance curves with high accuracy. In this paper, a digital twin of the thermal structure from semiconductor junction to the cooling system has been developed by structure function analysis of the finite element simulation results and the experimental data. The accurate representation of the thermal structure enables trustworthy further investigation of the thermal coupling among paralleling chips. The simulation results have essential indications about module internal thermal coupling as well as imbalance, and provide guidance for further optimisation of the packaging structure.