Delamination lifetime evaluation of IPM by accelerated power cycle test

Abstract

Key difference between high-power semiconductor and low-power semiconductor is self heating during operation. Self heating leads to extreme thermal change in semiconductor. Especially, regenerative energy applications tend to repeated intermittent operation. Thermal change leads to mechanical stress by CTE(Coefficient of Thermal Expansion) mismatch between substrate, bonding material(solder), bonding wire and chip material(Si). Consequently, it induces delamination or crack(solder, wire bonding). Each materials should be thermally well conductive, chemically stable, electrically well conductive and CTE should be similar to chip material to enhance power cycle life(or IOL(Intermittent Operating Life)). Accelerated life test was executed to predict intermittent operating life during actual application.