Abstract: A package to be mounted with semiconductor chips has a heat-radiating substrate having a thickness of smaller than 0.4 mm of a Cu—Mo composite as prepared by impregnating from 30 to 40% by mass of copper (Cu) melt into a green compact of molybdenum. The heat-radiating substrate is produced by preparing an Mo green compact through isostatic molding, mounting Cu on the Mo green compact, heating it to thereby impregnate copper into the Mo green compact to give a Cu—Mo composite, and rolling the Cu—Mo composite into a sheet substrate.

Abstract: A package to be mounted with semiconductor chips has a heat-radiating substrate having a thickness of smaller than 0.4 mm of a Cu—Mo composite as prepared by impregnating from 30 to 40% by mass of copper (Cu) melt into a green compact of molybdenum. The heat-radiating substrate is produced by preparing an Mo green compact through isostatic molding, mounting Cu on the Mo green compact, heating it to thereby impregnate copper into the Mo green compact to give a Cu—Mo composite, and rolling the Cu—Mo composite into a sheet substrate.

Abstract: A package to be mounted with semiconductor chips has a heat-radiating substrate having a thickness of smaller than 0.4 mm of a Cu—Mo composite as prepared by impregnating from 30 to 40% by mass of copper (Cu) melt into a green compact of molybdenum. The heat-radiating substrate is produced by preparing an Mo green compact through isostatic molding, mounting Cu on the Mo green compact, heating it to thereby impregnate copper into the Mo green compact to give a Cu—Mo composite, and rolling the Cu—Mo composite into a sheet substrate. In the isostatic molding process, at least two or more plates.

Abstract: In a plasma facing member exposed to a plasma beam of nuclear fusion reactors or the like, such as an electron beam, a tungsten layer is formed by the use of a CVD method and has a thickness of 500 micron meters or more. The tungsten layer may be overlaid on a substrate of molybdenum or tungsten and comprises included gases reduced to 2 ppm or less and impurities reduced to 2 ppm or less. The tungsten layer is specified by either a fine equi-axed grain structure or a columnar grain structure. Alternatively, the material of the substrate may be, for example, Cu alloy, stainless steel, Nb alloy, or V alloy.

Abstract: In a package of a semiconductor device mounted a semiconductor element and micro balls as electric contact points, the micro balls are composed of composite micro balls each of which has a core ball and an electrically conductive film around the core ball. The core balls have a sufficient rolling property with the diameter ranged from 30 to 100 &mgr;m. The diameter accuracy thereof is excellent. The electrically conductive film is formed by a solder plated layer which has a thickness of at least 10 &mgr;m uniformly formed on the outer surfaces. The composite micro balls are mounted onto a substrate. The dimensional accuracy of the Z axis of the package can be precisely controlled. Accordingly, the composite micro balls with the solder plated film has a thickness of at least 20 &mgr;m on the outer circumference of each core ball. The production method thereof, and the semiconductor package mounted a semiconductor element using the composite micro balls can be provided.

Abstract: A heat sink substrate comprises a Cu—Mo composite substrate composed of a molybdenum (Mo) green compact with which Copper (Cu) of 20-60 wt % is impregnated. It is preferable that the heat sink substrate is a rolled plate obtained by repeatedly warm rolling or cold rolling the Cu—Mo composite substrate and that the rolled plate does not include any fine void and unevenly impregnated copper, that is, copper and molybdenum are uniformly distributed therein.

Abstract: A heat sink substrate comprises a Cu—Mo composite substrate composed of a molybdenum (Mo) green compact with which Copper (Cu) of 20-60 wt % is impregnated. It is preferable that the heat sink substrate is a rolled plate obtained by repeatedly warm rolling or cold rolling the Cu—Mo composite substrate and that the rolled plate does not include any fine void and unevenly impregnated copper, that is, copper and molybdenum are uniformly distributed therein.

Abstract: In a plasma facing member exposed to a plasma beam of nuclear fusion reactors or the like, such as an electron beam, a tungsten layer is formed by the use of a CVD method and has a thickness of 500 micron meters or more. The tungsten layer may be overlaid on a substrate of molybdenum or tungsten and comprises included gases reduced to 2 ppm or less and impurities reduced to 2 ppm or less. The tungsten layer is specified by either a fine equi-axed grain structure or a columnar grain structure. Alternatively, the material of the substrate may be, for example, Cu alloy, stainless steel, Nb alloy, or V alloy.

Abstract: A heat sink substrate comprises a Cu—Mo composite substrate composed of a molybdenum (Mo) green compact with which Copper (Cu) of 20-60 wt % is impregnated. It is preferable that the heat sink substrate is a rolled plate obtained by repeatedly warm rolling or cold rolling the Cu—Mo composite substrate and that the rolled plate does not include any fine void and unevenly impregnated copper, that is, copper and molybdenum are uniformly distributed therein.

Abstract: In a plasma facing member exposed to a plasma beam of nuclear fusion reactors or the like, such as an electron beam, a tungsten layer is formed by the use of a CVD method and has a thickness of 500 micron meters or more. The tungsten layer may be overlaid on a substrate of molybdenum or tungsten and comprises included gases reduced to 2 ppm or less and impurities reduced to 2 ppm or less. The tungsten layer is specified by either a fine equi-axed grain structure or a columnar grain structure. Alternatively, the material of the substrate may be, for example, Cu alloy, stainless steel, Nb alloy, or V alloy.

Abstract: In a plastic-packaged semiconductor device molded by a synthetic resin, a heat sink is formed by a sheet which has a thermal expansion coefficient between 9.0.times.10.sup.-6 /K and 23.times.10.sup.-6 /K and a thermal conductivity greater than 200 W/m.multidot.K, which are selected in relation to those of the synthetic resin. The sheet is manufactured by mixing a first metal of a high melting point with a second metal of a low melting point lower than the first metal and by pressing and sintering the mixture. The first and the second metal may be molybdenum and copper, respectively. Alternatively, the sheet may be a composite sheet composed of a molybdenum mesh interposed between a pair of aluminum layers or a stacked sheet composed of a sintered layer of a mixture of molybdenum and copper and a coated layer of either molybdenum or copper.