Optimization design of double-sided cooling structure for RC-IGBT based on thermal simulation technology

Among the power electronic devices, the Reverse Conducting Insulated Gate Bipolar Transistor (RC-IGBT) has been widely adopted in high-power-density inverters and frequency converters because of its superior conduction performance and integrated diode characteristics. However, with the continuous increase in power density, thermal management has become a critical factor limiting the further development of RC-IGBTs. This paper presents an optimized design for double-sided cooling structures of RC-IGBTs based on multiphysics-coupled thermal simulations. Three-dimensional modeling was implemented in SolidWorks, and the thermal responses were analyzed using COMSOL finite-element simulation. By establishing a Cauer-type thermal network model, the dynamic distribution characteristics of junction temperature and thermal resistance were investigated. The optimized double-sided cooling structure significantly reduced junction temperature fluctuation amplitude, decreasing the maximum junction temperature from 86.6 to 66.3 °C while achieving a 29.06% reduction in junction-to-case thermal resistance, thereby substantially improving heat dissipation efficiency. Furthermore, thermomechanical stress analysis demonstrated that the new design exhibited a more uniform stress distribution and enhanced thermal stability.