Abstract: An aluminum-silicon carbide composite suitable for a base plate for power module, having an aluminum-silicon carbide composite, with a front and a rear surface plane, that is a flat plate-shaped silicon carbide porous body impregnated with a metal mainly containing aluminum, and an aluminum layer made of a metal mainly containing aluminum formed only on the front surface plane, wherein the rear surface plane of the composite is exposed to the outside, and the shape of the exposed aluminum-silicon carbide composite is rectangular, optionally having peripheral portions encompassing holes removed. Plating is imparted to the composite by providing an aluminum layer on the rear surface plane. Flatness of the composite is improved by grinding its rear surface so that the composite is exposed to the outside. Warpage after grinding the rear surface, is controlled by controlling the thickness of the aluminum layer.

Abstract: An aluminum-silicon carbide composite suitable for a base plate for power module is provided. A base plate for power module, comprising an aluminum-silicon carbide composite that is a flat plate-shaped silicon carbide porous body impregnated with a metal containing aluminum as the main component, and an aluminum layer made of a metal containing aluminum as the main component formed only on one of the principal planes of the composite, wherein a rear surface being the other one of principal planes of the aluminum-silicon carbide composite is exposed to the outside, and the shape of the exposed aluminum-silicon carbide composite is a rectangle or a rectangle from which portions encompassing holes in the peripheral portion are removed.

Abstract: A metal evaporation boat having improved wettability to a molten metal and having a prolonged life, and a method for evaporating a metal employing it. A metal evaporation heating element characterized by having one or more grooves in a direction not in parallel with a current direction, on an upper surface of a ceramic sintered body comprising titanium diboride (TiB2) and/or zirconium diboride (ZrB2), and boron nitride (BN). It is preferred that the direction not in parallel with the current collection is from 20 to 160° C. to the current direction, that the ceramic sintered body has a cavity and the groove is formed on the bottom surface thereof, and that a predetermined pattern is drawn by a plurality of grooves on the upper surface of the ceramic sintered body and/or on the upper surface of the cavity.

Abstract: A substrate for mounting an electronic component, includes a baseplate having a main surface formed with or without a recess. A ceramic substrate is provided on the main surface of the baseplate and has a smaller size than the baseplate. A metal layer is provided to cover both of the baseplate and the ceramic substrate. The metal layer has a surface remote from the baseplate and the ceramic substrate is made flat, the baseplate is made of a metal-ceramic composite of a metallic material and a ceramic material, and the metallic material in the composite and the metal layer have different compositions. Thus, an integral ceramic circuit board, which is resistant to repeated thermal stress and is superior in reliability can be realized.

Abstract: A substrate for mounting an electronic component, including a baseplate having a main surface formed with or without a recess. A ceramic substrate is provided on the main surface of the baseplate and has a smaller size than the baseplate. A metal layer is provided to cover both of the baseplate and the ceramic substrate. The metal layer has a surface remote from the baseplate and the ceramic substrate is made flat, the baseplate is made of a metal-ceramic composite of a metallic material and a ceramic material, and the metallic material in the composite and the metal layer have different compositions. Thereby, an integral ceramic circuit board, which is resistant to repeated thermal stress and is superior in reliability, can be realized.

Abstract: A substrate for mounting an electronic component, includes a baseplate having a main surface formed with or without a recess. A ceramic substrate is provided on the main surface of the baseplate and has a smaller size than the baseplate. A metal layer is provided to cover both of the baseplate and the ceramic substrate. The metal layer has a surface remote from the baseplate and the ceramic substrate is made flat, the baseplate is made of a metal-ceramic composite of a metallic material and a ceramic material, and the metallic material in the composite and the metal layer have different compositions. Thus, an integral ceramic circuit board, which is resistant to repeated thermal stress and is superior in reliability can be realized.

Abstract: A substrate for mounting an electronic component, comprising a baseplate having a main surface formed with or without a recess; a ceramic substrate provided on the main surface of the baseplate and having a smaller size than the baseplate; and a metal layer provided so as to cover both of the baseplate and the ceramic substrate; wherein the metal layer has a surface remote from the baseplate and the ceramic substrate made flat, the baseplate is made of a metal-ceramic composite of a metallic material and a ceramic material, and the metallic material in the composite and the metal layer have different compositions. There is provided an integral ceramic circuit board, which is resistant to repeated thermal stress and is superior in reliability.

Abstract: A silicon carbide composite which is a flat composite comprising a porous preform of silicon carbide and a metal containing aluminum as the main component, infiltrated into the porous preform, said composite having a warpage of at most 250 &mgr;m per 10 cm of the principal plane length of the composite.

Abstract: A metal-ceramics composite comprising a porous inorganic structure and a metal containing aluminum as the main component, infiltrated into the porous inorganic structure, wherein a part of the porous inorganic structure is made of an inorganic fiber and a hardened product of a hydraulic inorganic substance.

Abstract: A circuit substrate which has a ceramic substrate and an Al circuit comprising Al or an Al alloy bonded to said ceramic substrate via a layer comprising Al and Cu.

Abstract: A circuit substrate which has a ceramic substrate and an Al circuit comprising Al or an Al alloy bonded to said ceramic substrate via a layer comprising Al and Cu.

Abstract: Method for forming a ceramic circuit board by forming a metal circuit pattern on a ceramic board through an active metal ingredient-containing brazing material and removing an unnecessary part of the brazing material by chemical liquor treatment.

Abstract: A chlorosilane disproportionation catalyst comprising a tertiary amine of the formula: ##STR1## where each R represents an aliphatic hydrocarbon group and the sum of carbon atoms in the three aliphatic hydrocarbon groups as R is 12 or more, and a tertiary amine hydrochloride of the formula: ##STR2## where R is as defined above.

Abstract: A thermionic emission cathode comprises a cathode tip made of an alkaline earth metal or rare earth metal hexaboride, a metallic support for supporting a base of said cathode tip and a reaction barrier layer comprising colloidal carbon and a reaction barrier material which bonds said cathode tip and said metallic support in one body.

Abstract: A method for manufacturing a thermionic cathode is provided which comprises cutting a bar from a multi-layer structure having a first layer of thermoelectron emissive compound and a third layer of metal of high melting point, a second layer of reaction barrier being interposed between said first and third layers, the bar being cut in a direction substantially perpendicular to that of the layers, sharpening the end of the first layer of the bar and then providing current terminals with the third layer of the bar. According to the method of the invention, a thermionic cathode capable of emitting stable electron beams of high intensity for a long period of time can be manufactured.

Abstract: A thermionic cathode for an electron beam device is provided which comprises a first layer of thermoelectron emissive compound sharpened towards a point, a third layer of metal of high melting point and a second layer of reaction barrier interposed between the first and third layers, current terminals being attached to said third layer. According to the invention, a thermionic cathode capable of emitting stable electron beams of high intensity for a long period of time can be manufactured.

Abstract: An evaporation vessel for vacuum evaporation of electroconductive ceramic boat for use in the vacuum evaporation of a metallic or non-metallic substance by virtue of resistance heating, wherein the surface of the adjoining portion on the both sides of a cavity is lower than the top of the outside wall of the cavity.

Abstract: Metal is evaporated in a container which comprises an electrically conductive ceramic base whose surface in contact with the molten metal is coated with a film comprising, a main component selected from the group consisting of titanium carbide, zirconium carbide, hafnium carbide, vanadium carbide, niobium carbide, tantalum carbide, chromium carbide, molybdenum carbide, tungsten carbide, tungsten metal, tantalum metal and molybdenum metal.