| abstract |
A system for dissipating heat from semiconductor chips disposed on a substrate which may individually produce differing amounts of heat, the substrate secured to a device uniformly distributing the heat produced by the chips thereover in the form of a metal matrix composite of a thermally conductive material, preferably aluminum or copper, having layers of uniformly spaced fibers, preferably carbon, with a higher thermal conductivity than the metal of the metal matrix and embedded therein. Each layer has a plurality of such fibers in rows, each layer being orthogonal to the layers thereabove and therebelow. Preferably, none of the carbon fibers touch each other. The metal matrix is secured to a heat dissipating structure in the form of a housing having a sponge secured therein. The sponge is preferably of aluminum or copper and has a cellular structure, the cells having interconnecting porosity. The housing contains a fluid inlet and outlet whereby fluid travels through the sponge and withdraws heat from the walls of the sponge cells. In an alternative embodiment, the housing is secured to the metal matrix by means of an aluminum-silicon alloy braze layer which is brazed therebetween. Also, the metal matrix can be coated with a layer of pure aluminum to avoid or minimize corrosion. The sponge can be spaced from the housing walls containing the inlet and outlet to permit inlet fluid to travel through the sponge relatively uniformly throughout its entire volume rather than mainly in the direct path between inlet and outlet. |