Integrated circuit subassembly with thermally anisotropic heat transfer element

摘要

An integrated circuit heat transfer element (6,30) is made by selecting thermally conductive fibers having aspect ratios of length to diameter of more than 1, selecting a resin and combining the fibers and the resin to create a formable resin/fiber compound. The resin/fiber compound is formed into a composite material in part by applying pressure to the formable resin/fiber compound, which aligns the fibers, and when cured creates a thermally anisotropic composite material to maximize heat conduction along the aligned fibers. The thermally anisotropic composite material has a coefficient of thermal expansion (CTE) of less than about 10x10-6 cm/cm/ DEG C. The composite material has a thermal conductivity in the direction of the carbon fibers of at least 50 W/m DEG K. The IC device is preferably secured to the heat transfer element using a thermally conductive adhesive.