A New Thermal Model for Power Mosfet Devices Accounting for the Behavior in Unclamped Inductive Switching

The main aim of this work has been the analysis of the transient thermal behavior of several typologies of power MOSFET devices. The commonly used thermal model has been applied to different devices families with different breakdown voltages. The large difference between the experimental results and the simulation runs, performed with the classical approach for some kinds of devices, leads to correct the traditional mathematical thermal model and to build up a new one in which the real size of the epytaxial layer is taken into account. The new model shows a better fitting with the experimental evidence and confirms its suitability for all the proofed families of devices. The mathematical process to build up the model is developed, and a comparison is carried out between the measured temperatures on the device and estimation by the model. The results are shown and the good fitting of the achieved model with the experimental measurements demonstrate the suitability of the proposed approach.