Thermo-mechanical stress analysis for an integrated passive resonant module

In recent years, passive integrated power electronic modules (IPEMs), which have been implemented as resonant tanks in resonant dc-dc converters, have gained interest because of their merits for possibly reducing the total volume and improving manufacturability of the resonant converter system. However, the integration process for the passive IPEM increases the complexity of the thermal and mechanical behavior of the structure due to interactive heating of the module layers and mechanical inter-layer stresses. It is therefore essential to investigate the thermo-mechanical behavior of a passive IPEM to ensure reliable operation. In this paper, the methodology for thermo-mechanical analysis for a series resonant LC passive IPEM is developed. Especially, a three-dimensional thermo-mechanical model based on finite-element modeling is presented. The thermal analysis results were verified by an experimental prototype LC passive IPEM and temperature distribution measurement using an infrared camera and thermocouples. Results of the thermal analysis and the associated thermo-mechanical stress analysis are also discussed, illustrating the viability of the methodology developed for thermally induced mechanical stresses.