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: A high-quality and high-reliability rotary anode target for X-ray tubes, of which the mechanical strength at high temperatures is increased and which is applicable not only to low-speed rotation (at least 3,000 rpm) but also even to high-speed rotation at high temperatures, and also a method for producing it. The rotary anode has a two-layered structure to be formed by laminating an Mo alloy substrate that comprises from 0.2% by weight to 1.5% by weight of TiC with the balance of substantially Mo, and an X-ray generating layer of a W—Re alloy that overlies the substrate.

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: In order to provide cemented carbide, provision is made about tungsten carbide powder which has a grain size not smaller than 1 .mu.m and which is mixed with carbon powder and chromium powder to form raw powder. The tungsten carbide powder is formed by fine primary crystal particles of tungsten carbide and satisfies an inequality given by:Y>0.61-0.33 log (X),where Y denotes a half-value width of (211) crystal planes in tungsten carbide (JCPDS-card 25-1047, d=0.9020) measured by a X-ray diffraction method and where X denotes a grain size measured by the FSSS method. There is also provided a method of producing the composite carbide powder having tungsten carbide powder as a main element, the method comprising the steps of preparing tungsten powder which has a mean grain size not smaller than 1 .mu.m, mixing the tungsten powder with carbon powder and chromium powder into a mixture, and processing the mixture in a predetermined atmosphere into fine primary crystal particles of tungsten carbide.

Abstract: A long-life, inexpensive rotary anode for use in an X-ray tube having an X-ray generating layer formed by CVD on a graphite substrate and capable of producing high-power X-rays without the possibility of thermal cracks or delamination. When forming the X-ray generating layer of a tungsten-rhenium alloy on the graphite substrate through a rhenium intermediate layer by CVD, material gases are supplied intermittently so that the entire part or only the surface area of the X-ray generating layer will be formed of laminated structure of ultra-thin films each 0.1-5.0 microns thick. The content of rhenium in the tungsten-rhenium alloy forming the X-ray generating layer has a gradient form, i.e. increases from the interface with the rhenium intermediate layer toward the surface, so that the total amount of rhenium added can be reduced.

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.

Abstract: A method for manufacturing a rotary anode for use in an X-ray tube is proposed. The method has the step of forming, on a graphite substrate plate, an intermediate layer of rhenium by subjecting a metallic chloride to the thermal decomposition CVD process at a substrate temperature of 1200.degree. C. or more. The method further has the step of forming, on the intermediate layer, an X-ray generating layer of tungsten or tungsten-rhenium alloy by subjecting a metallic fluoride to the hydrogen reduction thermal CVD process.

Abstract: A rotary anode for use in an X-ray tube has a graphite substrate plate, an intermediate layer made of a metal that does not react with graphite, and an X-ray generating layer provided on the intermediate layer for generating X-rays when electron impact is applied. The intermediate layer is a rhenium film having an equiaxed grain structure. A method for manufacturing such a rotary anode is proposed. The method has the step of forming, on a graphite substrate plate, an intermediate layer of rhenium by subjecting a metallic chloride to the thermal decomposition CVD process at a substrate temperature of 1200.degree. C. or more. The method further has the step of forming, on the intermediate layer, an X-ray generating layer of tungsten or tungsten-rhenium alloy by subjecting a metallic fluoride to the hydrogen reduction thermal CVD process.

Abstract: A tungsten alloy is used as a material of an electrode wire for electric spark cutting. The tungsten alloy comprises one or more elements selected from the group consisted of Y, La, Ce, Pr, Nd, Pm, Sm, Eu, Gd, Tb, Dy, Ho, Er, Tm, Yb, Lu and oxides thereof. An electrode wire made of such a tungsten alloy handles an improved processing speed and the accuracy of the cut surface is also improved. The number of failures due to breaking of the electrode wire has been reduced and the tensile strength of the electrode wire has been increased. The same effect can be attained when a molybdenum alloy containing one or more oxides of elements selected from the group consisted of Al, Si and K is used as an alloying component in the alloy for making the electrode wire for electric spark cutting.