A bi-dimensional model for power MOSFET devices accounting for the behavior in unclamped inductive switching conditions

The aim of this work is the development of an improved model for the analysis of the transient thermal behavior of MOSFET power devices in UIS conditions. The proposed modeling technique allows to achieve a higher accuracy for the estimation of the temperature of the power semiconductor if compared with classical models. The epitaxial thickness of the device is taken now into account in a bi-dimensional domain, thus accounting both for the heat flux generation and propagation on the plane (valid assumption, but only for low voltage devices) but also along the other dimensions. The new developed model presents more accurate results than the ones previously presented and doesn't make use of empirical correction factors. The mathematical process to build up the model is developed, and a comparison is carried out between the measured temperatures on the device and the estimation by the model. The results are shown and the good fitting of the simulation runs with the experimental measurements demonstrates the correctness of the proposed approach.