Characterization of interfacial thermal resistance by acoustic micrography imaging

In high-power electronics modules, the heat generated by the power devices is transferred to the ambient environment by attaching a heat spreader to the semiconductor package to ensure efficient thermal management. Typical attachment materials introduce interfaces and/or interlayers of finite thickness. Using a scanning acoustic microscope (SAM), a non-destructive inspection tool, we can detect the cracks, voiding, porosity, coplanarity and delamination in the interface layer, which correlate to the measured thermal resistance of an interface. This investigation would result in optimizing the bonding process of the selected interface material, minimizing the void-content to ensure enhanced thermal management of power modules.