Abstract: A heat sink for a semiconductor device comprises a tungsten-copper composite body and a diamond film coated on the surface of the body. A method for fabricating a heat sink for a semiconductor comprises the steps of fabricating a tungsten-copper composite heat sink, modifying a surface of the heat sink by selectively dissolving copper from the surface of the heat sink, carrying out a process for supplying nuclei for growth of a diamond film on the modified surface of the heat sink, and coating the thusly processed surface of the heat sink with a diamond film. Preferably, a process for etching of a tungsten grain precedes selective dissolution of the copper.

Abstract: A method for fabricating a hermetically sealed tungsten-copper package container for a microwave device is provided with the steps of forming an injection feedstock by mixing a polymer binder with a tungsten powder having a particle diameter of 2 to 5 .mu.m and a purity 99.9 of weight percent, forming a three-dimensional part by applying a powder injection molding to the feedstock, obtaining a tungsten skeleton structure by eliminating the binder from the injection molded part, and carrying out a copper infiltration to a copper plate placed on the tungsten skeleton structure for two hours under a hydrogen atmosphere at a temperature of 1250.degree. C. The method incorporates an improved heat sink characteristic, a thermal expansion coefficient similar to that of GaAs, and a capability of applying thereto a strip wire connection, without an extra machining process.

Abstract: A tungsten skeleton structure fabrication method employed in an application of a copper infiltration and tungsten-copper composite fabrication method includes the steps of forming a source powder by coating the tungsten powder surface having a purity of 99.9 weight percent and 2.about.5 .mu.m in size, with nickel by less than 0.06 weight percent (600 ppm), forming an injection molded admixture by admixing a source powder and a polymer binder, carrying out a powder injection molded with regard to the admixture, and obtaining a tungsten skeleton structure by removing the polymer binder from the resultant injection molded body. The method prevents the molded body from being unevenly shrunken during a liquid phase sintering for thereby decreasing its production cost.

Abstract: A fabrication method for a molybdenum disilicide sintered body in which a molybdenum disilicide powder having excellent oxidation resistance is sintered in a low-temperature sintering method and compacted at a low temperature and under no pressure, includes carrying out a milling on a molybdenum disilicide powder at a low temperature, providing a diffusion path required to sinter the molybdenum disilicide on which a milling is performed, and sintering the resultant powder under the atmosphere of hydrogen or argon gas.