Heat generated in an electronic component must be removed to the ambient environment to ensure that during operation the device is not damaged and the reliability of the system is maintained. To enhance heat dissipation, heat-sinks are mated to the heat generating component. However, these two commercially available substrates are never perfectly smooth or flat, and therefore full contact is not made across the substrates. Typical contact area can consist of more than 90% air voids, which represents a significant resistance to heat flow as air is a poor thermal conductor. The image on the left represents the uneven surfaces on a macro scale, demonstrating two concave surfaces for example. For thermal management, a thermal interface material is used between the two substrates to eliminate the air voids, improving heat transfer. However, even with a thermal interface material in place, micro air voids can exist between two surfaces, depicted in the image on the right. The contact resistance between the material and the two mating substrates is the measure of how a material resists the flow of heat. Therefore, the contact resistance is dependent on the surface conditions including substrate flatness, roughness, and clamping pressure.