An improved way to measure thermal impedance of insulated gate bipolar transistor (IGBT) module for power electronic packaging

Recently, silver paste, silver epoxy, and solders were commonly used as die-attach materials for power electronic packaging. Thermal performance of these materials should be paid attention to since reliability of sintered or soldered jointsis highly dependent on the thermal performance. To accurately investigate the transient thermal behavior of sintered or soldered joints in electronic applications, an improved way and system for thermal impedance measurement were developed in this paper. A series of measurements utilized gate-emitter voltage as temperature-sensitive parameter at varies heating time and heating power were conducted. Significantly, through changing the heat input, the specific thermal impedance of any layer could be obtained with high accuracy, repeatability, and stability. In this way, it would be useful to understand how thermal performance of power modules varies with architecture and materials for power electronic packaging.