Junction Temperature and Failure Behavior of High-Power Press Pack vs. Module Diodes Under High Anomalous Surge Currents

Junction temperature is considered a critical parameter that can directly affect the reliability and power handling capabilities of semiconductor devices. Effective thermal management, particularly under high-surge-current conditions, is therefore essential to maintain a lower junction temperature in order to enhance device performance and prevent device failure. Among various thermal management strategies, packaging technology plays an important role in optimizing junction temperature and enhancing the robustness of the device. In this article, a comparative analysis of high-power diodes is performed by investigating their junction temperature behavior and surge current handling capability. Moreover, an insulated module diode and a press-pack diode with pressure contact technology (PCT), both with identical specifications and power ratings, are selected for analysis. A 10 ms half-sine surge current waveform generator is developed both experimentally and in simulations to replicate realistic surge events. Experimental measurements of the forward voltage drop across varying surge levels are used to analyze device failure behavior. In addition, electro-thermal simulations are also employed in PSIM 2025.0 software to estimate and compare the temperature. Furthermore, this study enables practical insights into device thermal performance, robustness, and surge current handling capabilities, enabling a performance comparison between the two packaging technologies. Keywords: junction temperature; surge current capability; failure behaviour; electro-thermal modelling; pressure contact technology; high-power semiconductor devices