Microstructural evolution during the crack propagation at the bond-wire contact area of IGBT power modules upon power cycling

This paper proposes an analysis for the main microstructural changes at the chip topside level in the metallic interconnections of SKIM63 IGBT power modules due to aging processes caused by power cycling. The objective is to correlate these changes with the degradation processes dominating such positions. In this study, it is deduced that grains stability drives their texture evolution upon cycling. Transformations of texture components, which indicate whether the structure is recrystallized or deformed, are analyzed at different cycling stages. Afterward, the effect of the evolution of the disorientation angle's distribution on the crack passage is discussed. The size of grains directly related to their strength was as well shown to affect the cracking manner. Finally, the cracking procedure is interpreted in detail. •Microstructural changes at the wire-metallization contacts were shown to be synchronous with the degradation processes.•Grain’s texture evolution is driven by increasing the grains stability through decreasing their surface energy.•Effects of transformations in a) texture components b) disorientation angles and c) grains sizes on cracking are discussed.•Finally, the cracking scenario is interpreted in detail by relating its evolution with the microstructural evolution.