Researcher / Associate Engineer (M/F) Study of Thermomechanical Fatigue Behavior of a Power Module Encapsulated in Epoxy Resin 

Context and description

 Nowadays, power modules are key components used in electrical energy conversion systems across various fields such as transportation (railways, electric vehicles, etc.), renewable energy (photovoltaics, wind turbines), and industrial plants (motion control, drives, etc.). These modules are increasingly used and face harsh environmental and operating conditions (high temperatures, mechanical vibrations, humidity). Long-term exposure to significant temperature variations and complex mission profiles makes these components prone to fatigue and wear-out, leading to failures. Poor reliability design of a power module can result in unexpected downtime, unscheduled maintenance, revenue loss, electronic waste, and non-compliance with safety regulations. 

To meet high reliability requirements, improved power module structures have been developed, such as modules encapsulated in epoxy resin offering longer lifetime. However, these new technologies are also subjected to aging during usage and reveal new degradation mechanisms. Therefore, understanding these mechanisms through numerical simulation tools allows for predicting their operational lifetime and improving future designs. 

The proposed position aims to develop a multiphysics model to reproduce the electro-thermo-mechanical behavior of a power module, integrating IGBT (Insulated-Gate Bipolar Transistor) semiconductor chips encapsulated in epoxy resin. The model will quantify aging indicators (stress fields, strain, cracks, etc.) to estimate lifetime. In parallel with the theoretical part, accelerated cycling tests will be studied and simulated to validate the established lifetime model.