Modeling and Characterizing for Thermal Resistance of Double-sided Cooling Power Module

Due to considerably reduced junction-case thermal resistance, the double-sided cooling (DSC) packaging can dramatically promote the power density of converters compared with the single-sided cooling (SSC) counterpart, which is the cutting-edge of the power integration. However, the thermal-dependent modeling and characterizing of the DSC power module still follow the methodologies of the SSC power module, and the specific double channel thermal paths of the DSC power module are overlooked. Therefore, the physical insight, thermal model, and assessment approach are lacked to understand the thermal resistance of the DSC power module, thereby locking the research development, reliability facilitation, and massive production of the DSC power module. In this paper, with the aids of the concepts of isothermal surface and temperature gradient, the thermal mechanisms of the SSC and DSC power modules were revealed, respectively. Based on the proposed physical essence of the DSC power module, the thermal network model of the DSC power module was created. Moreover, concerning the DSC power module, the principles of the thermal resistances with single path and double thermal paths were clarified. Comprehensive simulation results and experimental measurements ensured the feasibility and validity of the developed model models and methods. It was found that the junction-case thermal resistance of the DSC power module was not the simple parallel connection of the two thermal resistances of the partial SSC power modules physically, mathematically, or experimentally. Furthermore, compared with the SSC power module, the DSC power module could save 73% footprint while reducing 65% junction-case thermal resistance. These findings are extremely significant for the development, implementation, and standardization for the thermal resistance of the next-generation semiconductor devices. © 2022 Chin. Soc. for Elec. Eng.