Direct 2-Way Coupled Electro-Thermal Simulation of Temperature and Current Distribution in Power Devices

Thermal measurements based on the VCE(T)- method only deliver an area related average temperature of the devices with no information about the maximum temperature. Thermal simulation based on FEM software neither considers the temperature dependence of losses in the devices, nor does it take into account the parasitic resistance of the current paths to parallel devices in the module design. Therefore, 2-way coupled electro-thermal simulations must be applied for realistic identification of hot spots. In this paper, we introduce a method of direct 2-way coupled electro-thermal simulation in ANSYS, which takes into account the temperature dependent current distribution given by the VF(IF,T)-characteristic of the device as well as the impact of parasitic resistances along the current paths of paralleled devices.