Phase Change Material Integrated with Power Module Substrate for Junction Temperature Suppression

As the large-scale application of new energy generation systems, power electronic equipment is facing complex and variable operating conditions, such as short-term overloads and peak-to-valley switching, leading to long-term large junction temperature fluctuations of their core power devices, accelerating their aging and failure. To address the problem of concentrated thermal stress in power modules under complex operating conditions in grid systems, this paper proposes a heat dissipation substrate design concept integrated with phase change material (PCM). To ensure the optimal filling effect of the PCMs, the concept of the optimal volume ratio of PCMs is proposed and verified through parametric simulation. Finally, a PCM heat sink substrate sample is fabricated, and the experimental test results show that the PCM structure can suppress the temperature rise by more than 20% and reduce the maximum temperature fluctuation by 11.13°C under the same test condition.