A Unified Microscopic and Macroscopic Thermal Contact Resistance Model

There are two types of thermal contact resistance at the interface of two solids. One of them is due to the constriction of heat flow lines at the interface, commonly known as thermal contact resistance. The other type of constriction resistance is microscopic in nature. If the characteristic dimension of the constriction becomes comparable to the mean free path of the heat carriers then there is a ballistic component to the constriction resistance. For different materials on the two sides, thermal boundary resistance due to acoustic mismatch becomes important. In this paper a unified model is developed which accounts for both microscopic and macroscopic contact resistances.