Fundamental Study on Thermal Characteristics of Heat Spreaders

A heat spreader is one of the solutions for thermal management of electronic and photonic systems. By placing the heat spreader between a small heat source and a large heat sink, the heat flux is spread from the former to the latter, resulting in a lower thermal spreading resistance between them. There are many types of heat spreaders known today having different heat transfer modes, shapes and sizes. This paper describes the theoretical study to present the fundamental data for the rational use and thermal design of heat spreaders. Two-dimensional disk-shaped mathematical model of the heat spreader is constructed, and the dimensionless numerical analysis is performed to investigate the thermal spreading characteristics of the heat spreaders. From the numerical results, the temperature distribution and the heat flow inside the heat spreaders are visualized, and then the effects of design parameters are clarified. The discussion is also made on the discharge characteristics of the heat spreaders. Moreover, a simple equation is proposed to evaluate the heat spreaders.