Abstract: Heat-dissipating microcircuit substrate, having coefficients of thermal expansion adjusted to match the materials of the microcircuit mounted thereupon, are manufactured by powder metallurgy using carbides resulting from the combination of various types of carbons and wetting agents.

Abstract: High density heatsinks for microcircuit packages are formed by first mold-pressing a composite powder of free-flowing spray-dried particles of an inexpensive high thermal conductivity material having a high coefficient of thermal expansion (CTE) such as copper and at least one other low CTE material such as tungsten, the proportions of which are adjusted to match the CTE of the microcircuit material. The pressed compacts are sintered in order to achieve an homogeneous distribution of the melting copper throughout the structure. A multilevel embodiment of the heatsink comprises two bonded layers of metals or composites having their coefficients of thermal expansion adjusted to match those of the semiconductor material and of any supporting structures respectively, wherein the second layer in contact with the supporting structure has a high CTE and the other has a lower CTE.

Abstract: High density heatsinks for microcircuit packages are formed by first mold-pressing a composite powder of free-flowing spray-dried particles of an inexpensive high thermal conductivity material having a high coefficient of thermal expansion (CTE) such as copper and at least one other low CTE material such as tungsten, the proportions of which are adjusted to match the CTE of the microcircuit material. The pressed compacts are sintered in order to achieve an homogeneous distribution of the melting copper throughout the structure. A multilevel embodiment of the heatsink comprises two bonded layers of metals or composites having their coefficients of thermal expansion adjusted to match those of the semiconductor material and of any supporting structures respectively, wherein the second layer in contact with the supporting structure has a high CTE and the other has a lower CTE.

Abstract: High density heatsinks for microcircuit packages are formed by first mold-pressing a composite powder of free-flowing spray-dried particles of copper and at least one other denser material such as tungsten and/or molybdenum, the proportions of which are adjusted to match the thermal expansion characteristics of the microcircuit material. The pressed compacts are then heated in a sintering furnace at 1,200.degree. C. to 1,350.degree. C. in order to effect an homogeneous distribution of the melting copper throughout the structure. The process results in a readily usable component having good thermal conductivity and matched thermal expansion that requires no further machining.