Transient Electro-Thermal Coupled System Simulation - Modeling Approach and Experimental Validation

摘要

This contribution describes an approach for modeling a coupled electro-thermal design problem for the transient system simulation based on the analog circuit simulator SPICE - means: the time-varying electrical functional behavior of several neighboring components influence the time-varying thermal behavior of the setup and interconnection environment, which in turn affects the time-varying electrical behavior of these components. Due to the SPICE model description this is currently not possible. For this purpose, both electrical and thermal modeling methods as well as the coupling of these models are presented. The electrical model is based on the fundamental equations of semiconductor physics. With the help of the respective physical parameters, the electrical model can easily be extended to an existing library component or that of a manufacturer component SPICE description. The thermal model is based on a modified Foster model extracted from transient FEM simulation results, using the thermal step response. Thus, during the coupled transient simulation, both, the electrical behavior of the component, due to its self-heating, and the coupling heating of adjacent components, can be taken into account. The method is shown and experimentally verified by the example of two interacting MOSFETs with D2PAK packages, using a specially developed test board.