Validation of Dynamic Thermal Simulations of Power Assemblies Using a Thermal Test Chip

Thermal simulation is the main thermal design tool used to predict temperature distributions of complex power electronics assemblies. Nevertheless, the validation of the simulation results remains a complex problem, mainly in dynamic operation, due to the difficulty in measuring semiconductor device temperatures. This paper proposes a methodology for the accurate validation of CFD 3-D thermal simulations of power modules. A test power assembly structure based on two thermal test chips and an insulated metal substrate, has been measured with single power pulse excitations. The corresponding thermal simulations have been performed to reproduce the experimental conditions, close to the real operational ones. A very good agreement between simulation and experience has been obtained. Fine adjustment and analysis of some critical parameters (thermal conductivities, etc.) is possible using this approach.