R. Prieto (Sp), J. Narciso, E. Louis, University of Alicante (Spain)
Carbon-metal matrix composites are a very attractive materials for thermal applications in microelectronics, given
their very high thermal conductivity in at least two planes. Therefore, in an attempt to obtain a good thermal
conducting material as well as a low Coefficient of Thermal Expansion (CTE), a mixture of reinforcements
(graphite and carbon fibre) was infiltrated with liquid alloys. The role of two reinforcing materials are following:
while graphite reinforcement increases thermal conductivity in the plane direction, the carbon fibre helps to
reduce the CTE of the alloy in the same direction. In the present work, graphite-carbon fibre preforms were
infiltrated with Al/Si and Ag/Si alloys by means of gas pressure to produce an anisotropic composite. The
influence of the volume fraction in the thermal conductivity and CTE was evaluated. The experiments determined
that the manufactured composites has a adequate thermal behaviour to be used as low cost materials in heat
spreaders for micro and optoelectronics.