INFLUENCE OF HEAT TREATMENT ON THE PROPERTIES OF HIGH THERMAL CONDUCTIVITY GRAPHITE COMPOSITES

摘要

Thermal management is key to improving the performance and reliability of electronics systems. The use of 'traditional' packaging materials (e.g. aluminium and copper), limits conductive cooling efficiency, especially for high heat fluxes. This has driven development of 'third generation' high-performance materials which have ultra-high thermal conductivities, low coefficients of thermal expansion and low densities (1). Most of these materials incorporate carbon in some form. Natural crystalline graphite, with its high in-plane thermal conductivity and relatively low cost, is very attractive for thermal management. Foil materials are well-established, and anisotropic composites are marketed (e.g. for heat sinks), and continue to be developed. There are several examples of carbon-bonded materials in the literature. Mesophase pitch as a binder could, quite reasonably, be expected to produce the highest conductivity composites (2,3). However, factors of cost, availability and processing requirements, remain drivers to look at alternative binders.