Copper alloy-impregnated carbon-carbon hybrid composites for electronic packaging applications

Porous carbon-carbon preforms, based on three-dimensional networks of PAN ( Polyacrylonitrile)-based carbon fibers and various volume fractions of chem ical vapor-deposited (CVD) carbon, were impregnated by oxygen-free, high-co nductivity (OFHC) Cu, Cu-6Si-0.9Cr, and Cu-0.3Si-0.3Cr (wt pct) alloys by p ressure infiltration casting. The obtained composites were characterized fo r their coefficient of thermal expansion (CTE) and thermal conductivity (K) along the through-thickness and two in-plane directions. One composite, wi th a 28 vol pct Cu-0.3Si-0.3Cr alloy, showed outstanding potential for ther mal management applications in electronic applications. This composite exhi bited approximately isotropic thermal expansion properties (CTE = 4 to 6.5 ppm/K) and thermal conductivities (k greater than or equal to 260 W/m K).