Abstract: A homogeneous sintered composite made by press-forming a homogeneous mixture of powders of an agglutinating component, a second component having a melting point higher then the agglutinating component, and an exothermically reactive component to form a compact; heating the compact, then inducing an exothermic reaction of the reactive substance which generates sufficient additional heat to melt the agglutinating component without melting the high melting point component. For electronic microcircuit heat-dissipation applications the agglutinating component is a high thermal conductivity metal, and the high melting point component has a low thermal expansivity, whose proportions are adjusted to match the thermal expansion characteristics of microcircuit material. To reduce porosity, the reacted compact is pressed again while the agglutinating component is still in the liquid phase. For low weight applications the second material has high specific thermal conductivity.

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.