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Metal matrix composites (MMCs) reinforced with vapor-grown carbon fiber (VGCF) may offer thermal conductivity superior to materials currently used for thermal management while also providing an adjustable coefficient of thermal expansion (CTE) and low density. Extrapolating from results on aluminum MMC with lower loadings of VGCF suggest that aluminum and copper MMCs can attain a best-direction conductivity in excess of 1000 W/m-K. Alternatively, isotropic in-plane conductivity may reach up to 800 W/m-K, while matching the CTE of important semiconducting materials.

The development of chemically vapor deposited (CVD) diamond promises to greatly impact numerous technologies, and in particular the field of thermal management. Despite its current high cost, the physical properties of CVD diamond are so attractive, compared to currently implemented materials, that its use is justified in a few demanding or previously impossible applications. Unfortunately, at $50 or more per carat, the cost/performance ratio is well beyond the limits that would make it useful for many more widely spread applications. This paper describes an affordable variant of CVD diamond that is under development for thermal management in electronics. This material, designated “diamond/carbon/carbon composite,” consists of a carbon/carbon composite that is partially infiltrated with CVD diamond in the surface region. The performance advantages of DCC relative to current thermal management materials are analyzed, and the cost advantages relative to pure CVD diamond are discussed.