Reliability Enhancement of Power Modules by Restricting Junction Temperature Fluctuation through Increased Transient Thermal Capacity

Power modules are widely used in traction applications and renewable power generation, which require high reliability. In the harsh environment, the power modules must experience deep power cycling which causes large temperature fluctuations and hence leads to fatigue stresses. In power modules, reducing the chip junction temperature fluctuation can significantly improve their reliability. This paper proposes a power module design with considerably reduced junction temperature fluctuation using phase change material (PCM) as part of the thermal management. By both simulation and experiment, it is to be demonstrated that the junction temperature variations of the chips are significantly reduced as compared to the conventional power modules. Thus, the reliability of the power modules in concern can be increased.