Extending the Power-Cycling Lifetime of SiC Modules Operating at 225°C

Abstract

This paper reports on the development of a SiC power device packaging technology that extends the power-cycling lifetime to 300,000 cycles at temperatures above 200°C, which is the criterion for high-reliability applications. By mounting a buffer layer with an adjusted coefficient of thermal expansion (CTE) less than that of SiC, the creep-fatigue of the aluminum chip electrode is suppressed and lifetimes of 472,000 cycles at 65 to 200°C and 425,000 cycles at 65 to 225°C are achieved. In addition, the mechanism of the lifetime extension is discussed using cross-sectional structural observation, transient thermal resistance analysis, and stress-strain simulation utilizing the finite element method.