Experimental Reliability Assessment of ACEPACK SMIT Power Module

This paper presents a method to study the reliability behavior of the ACEPACKTM SMIT, which is a top side-cooled power module employing high-voltage silicon MOSFETs in a half bridge topology. The experimental test involves power cycling: this is an accelerated stress test, which allows monitoring a temperature-sensitive electric parameter to study the thermal behavior of the package. The efficiency of heat exchange between the module and the cooling plate surfaces is strongly influenced by the thermal interface material (TIM) used between them. TIM is designed to fill gaps and voids between two surfaces, in order to to increase the effective contact area and improve thermal conductivity at the interface. In this work, the thermal performance of two different TIMs, a thermal grease and a phase change material, will be analyzed. The aim of the paper is to provide an experimental approach for characterizing the reliability behavior of power modules, considering the thermal behavior when different TIMs are considered.