Experimental measurement and simulation of thermal performance due to aging in power semiconductor devices

Power cycling in operating power semiconductors creates stresses in the device package. These stresses cause cracks to grow in the solder die-attach layer, leading to voids between the silicon and the heat spreader. The thermal performance of power semiconductor devices is eventually compromised by these voids. This study compares the thermal impedance of modules with varying void area at a constant power dissipation level in order to develop a relationship between thermal impedance and void area. The effect of aging on thermal transient behavior is then correlated to finite element thermal simulations. Conclusions about the impact of thermal performance changes due to aging are created to help designers accommodate for the growth of age-related defects and their effects on operating temperature of power semiconductor devices.