Thermal characterization of high thermal conductive graphites reinforced aluminum matrix composites

Due to the development of high power density and high heat flux of IC and LED components and devices, the thermal management of microelectronics has become a very critical issue in 3C and optoelectronic industries. This has lead to the requirement of high thermal performance materials and thermal modules. To enhance the thermal performance of current thermal modules, it is very important to develop advanced thermal management materials to replace the conventional monolithic metals. In this study some kinds of graphites reinforced aluminum matrix composites were developed. The effects of reinforcement types and its volume fraction on thermal properties such as thermal conductivity as well as the thermal expansion coefficient were studied. Moreover, their thermal performance such as heat spreading resistance and thermal resistance compared to pure aluminum and copper were also conducted. From the results, it showed that the thermal conductivity of graphite/Al composites can reach to 500~600 W/m.K in X-Y plane and 40~100 W/m.K in cross plane with thermal expansion less than 10 ppm/K and density less than 2.5 g/cc; The spreading resistance of this composite is 2~5% lower than the one of pure copper, and 25% lower than the one of pure aluminum.