Reliability of Power Modules in Corrosive Environments: Effect of Heating on Dendritic Corrosion Growth in the Isolation Trenches

Environments with high humidity and corrosive gases have been shown to cause dendritic corrosion growth in isolation trenches of power semiconductor modules. In time, the corrosion products can grow long enough to bridge the isolation trenches and cause failure of the component, and the device the component is part of. In this paper, applied heating was shown to effectively inhibit dendritic corrosion growth by reducing the effective relative humidity and thereby the thickness of the adsorbed water layer on the ceramic substrate surface. The findings can be applied to enhance the reliability of power electronic devices e.g. frequency converters, including those with standard components without special corrosion-resistant packaging.