Integration of a multi-physics model in a reliability-based design framework: application to power converters

Structures of power converters constitute very complex systems, the behaviour of which introduces several phenomenons (electric, thermal and mechanic). An accurate modelling of their behaviour, thus, requires a multi-physics model which makes it possible to take into account the physical phenomenon in consideration. To achieve this, a FEM code (e. g. MulPhyDo) adapted to power converters and dedicated to simulation of structure in a multi-physics context has been built in the laboratory. The aim of the present study is to include in the modelling the existence of randomness and uncertainties, particularly of interest in the case of power converters. In order to achieve this, the multi-physics FEM code is coupled with a program dedicated to structural reliability analysis, in an Oriented Object Programming context. In this way, it is possible to compute the failure reliability of the structure under consideration and the sensitivity of the reliability index to each random variable. An application example of a microelectronic package is presented.