2D Thermal propagation analysis of discrete power devices based on an innovative distributed model technique and CAD framework

Stress and reliability analysis through accurate predictive models is required in order to guarantee higher levels of quality in terms of robustness of discrete power devices. This paper focuses on thermal modeling and simulation of Power MOSFETs, Power Bipolars, Schottcky Diodes and HFETs made with both consolidated silicon technologies and advanced ones on new materials. These devices, due to their peculiar characteristics, are used in a wide range of products, such as SMPS (Switched-Mode Power Supply), AC/DC converters (traditional silicon) and microwave wireless applications. The objective of this work is to describe an innovative distributed model technique and the development of a thermal-aware modeling framework covering thermal modeling issues and simulation aspects that can be found in the industrial context. A methodology for generating a lumped-element distributed model for a silicon power MOSFET device that takes into account the effects of layout parasites will be shown. The proposed technique exploits the high-frequency modeling approach of microstrips and striplines to describe the effects of the passive parts on active elementary transistor cells. The strategy described could be relevant in order to improve the design of new generations of devices; in the absence of careful design considerations, devices may cause reliability problems.