Numerical simulation and modeling of thermal transient in silicon power devices

The description of thermal non-uniformity in large area power MOSFETs requires the modeling of a thermal network to account for the thermal interaction between adjacent devices. In this work we propose a methodology to derive an equivalent thermal network which is able to predict the thermal transient as a function of the longitudinal distance from the heat source. The thermal resistances and capacitances are calculated by assuming a cylindrical propagation of the heat. Electro-thermal numerical simulations are performed in order to study the heat propagation inside the device and to verify the accuracy of the proposed model.