Bond graph multi-physics modeling of encapsulating materials in power electronic modules

Abstract

This paper focuses on multi-physics modeling of encapsulating gels in power electronic modules for transient and steady-state simulation. With the emergence of wide-bandgap semiconductors such as SiC or GaN, operating at a higher temperature than conventional Si power chips, this passive element of the packaging appears as a few studied element sensitive to thermal and mechanical stresses. A thermo-mechanical coupled modeling of the material, based on bond graph representation, is presented. This approach allows to establish, under the same formalism, an analogy between the different physical domains. From this analogy, a multi-physical nonlinear state space representation is built, allowing transient simulation of the thermo-mechanical behavior of the material. This way of modeling and simulating is particularly adapted for a preliminary study during the upstream phases of design of the power electronic modules. It quickly establishes the maximum temperature and mechanical strains experienced by the gel.