Modeling of thermal network in silicon power MOSFETs

In this work we propose a methodology to define an equivalent resistive thermal network that allows to model the lateral heat propagation through the silicon substrate of power devices. The basic idea is to split the substrate in basic elements of length ΔL and to associate to each element, lumped thermal resistances. The proposed model is validated by comparison with electro-thermal numerical simulations in silicon Power MOSFET technology. The proposed thermal network accurately predicts the temperature increase as a function of the distance from the heat source.