Design of Power Modules Using Containers Filled With Phase Change Materials as Device Top Interconnection for Power Peak Management

Abstract

In some applications, it can be useful to use occasionally power semiconductor devices above their nominal current for brief durations in order to deliver the additional requested power for the electric system. For such conditions, this study aims to design a new class of power modules with integrated phase change material (PCM) in a container serving as top device interconnection. This solution does not alter the cooling under nominal conditions where the bottom side of the power devices is conventionally used. During the over power duration, the PCM melts and absorbs rapidly the excessive heat. Hence, the increase of the junction temperature (Tj) in abnormal conditions can be slowed down. For a specified mission profile, the impact of the Cu to PCM vol. ratio on the Tj is evaluated as well as the impact of the contact area between the Cu and the PCM. Moreover, the optimal thickness of the container is defined. Finally, in order to evaluate the effectiveness of the solution, a comparative analysis with other conventional assemblies presenting the same weight is achieved under various heat transfer coefficients.