Abstract: There is provided a metal/ceramic circuit board capable of eliminating discrepancy during mounting of parts to improve the reliability of mounting of the parts. The metal/ceramic circuit board has a ceramic substrate 10, and a metal circuit plate (a copper plate 14) bonded to the ceramic substrate 10, the metal circuit plate having a thickness of 0.1 mm to 0.5 mm, and the metal circuit plate having a skirt spreading length (a dimensional difference between the bottom and top portion of the peripheral edge portion of the metal circuit plate) of less than 50 &mgr;m.

Abstract: There is provided a method for producing a metal/ceramic bonding article, the method including the steps of: bonding a metal plate 12 of an alloy containing copper and nickel directly to at least one side of a ceramic substrate 10; applying a resist 14 on a predetermined portion of the metal plate 12 to remove an undesired portion of the metal plate 12 by etching; and removing the resist 14 to form a pattern having a predetermined shape of the alloy on the ceramic substrate 10. According to this method, it is possible to reduce the displacement failure of parts to improve productivity and to prevent bonding failure during the mounting of a semiconductor device or the like thereon.

Abstract: There is provided a method for producing a metal/ceramic bonding article, the method including the steps of: bonding a metal plate 12 of an alloy containing copper and nickel directly to at least one side of a ceramic substrate 10; applying a resist 14 on a predetermined portion of the metal plate 12 to remove an undesired portion of the metal plate 12 by etching; and removing the resist 14 to form a pattern having a predetermined shape of the alloy on the ceramic substrate 10. According to this method, it is possible to reduce the displacement failure of parts to improve productivity and to prevent bonding failure during the mounting of a semiconductor device or the like thereon.

Abstract: There is provided a metal/ceramic bonding article which ensures sufficient thermal shock resistance and has a substrate having a small outside dimension and which has both high reliability and compactness. The metal/ceramic bonding article comprises: a ceramic substrate; and a metal plate bonded to the ceramic substrate via a brazing filler metal, wherein the brazing filler metal protrudes from the bottom face of the metal plate by a length which is longer than 30 &mgr;m and which is 250 &mgr;m or less, or wherein the brazing filler metal protrudes from the bottom face of the metal plate by a length which is 25% or more of the thickness of the metal plate.

Abstract: The present invention provides metallocene compounds which exhibit high polymerization activity for production of highly stereoregular polymers, as well as a production process for olefin polymers which employs olefin polymerization catalysts containing the compounds, and olefin polymers obtained by the production process.

Abstract: There is provided a metal/ceramic circuit board capable of eliminating discrepancy during mounting of parts to improve the reliability of mounting of the parts. The metal/ceramic circuit board has a ceramic substrate 10, and a metal circuit plate (a copper plate 14) bonded to the ceramic substrate 10, the metal circuit plate having a thickness of 0.1 mm to 0.5 mm, and the metal circuit plate having a skirt spreading length (a dimensional difference between the bottom and top portion of the peripheral edge portion of the metal circuit plate) of less than 50 &mgr;m.

Abstract: After copper plates 14 are bonded to both sides of a ceramic substrate 10 via a brazing filler metal 12, UV curing alkali peeling type resists 16 are applied on predetermined portions of the surfaces of the copper plates 14 to etch undesired portions of the copper plates 14 to form a metal circuit portion. While the resists 16 are maintained, undesired portions of the brazing filler metal 12 and a reaction product, which is produced by a reaction of the brazing filler metal 12 with the ceramic substrate 10, are removed (or undesired portions of the brazing filler metal 12 and a reaction product, which is produced by a reaction of the brazing filler metal 12 with the ceramic substrate 10, are removed, and the side portion of the metal circuit portion is etched). Thereafter, the resists 16 are peeled off, and an Ni—P electroless plating 18 is carried out.

Abstract: There is provided a metal/ceramic bonding article which ensures sufficient thermal shock resistance and has a substrate having a small outside dimension and which has both high reliability and compactness. The metal/ceramic bonding article comprises: a ceramic substrate; and a metal plate bonded to the ceramic substrate via a brazing filler metal, wherein the brazing filler metal protrudes from the bottom face of the metal plate by a length which is longer than 30 &mgr;m and which is 250 &mgr;m or less, or wherein the brazing filler metal protrudes from the bottom face of the metal plate by a length which is 25% or more of the thickness of the metal plate.

Abstract: There is provided a method for producing a metal/ceramic bonding article, the method including the steps of: arranging a metal plate 12 of an overall-rate solid solution type alloy on a ceramic substrate 10; and heating the metal plate 12 and the ceramic substrate 10 in a non-oxidizing atmosphere at a temperature of lower than a melting point of the alloy to bond the metal plate 12 directly to the ceramic substrate 10. According to this method, it is possible to easily bond an alloy plate directly to a ceramic substrate, and it is possible to inexpensively provide an electronic member for resistance without causing the alloy plate to be deteriorated.

Abstract: A polypropylene composition comprising 0.001 to 10 parts by weight of a polyethylene having an intrinsic viscosity [&eegr;E] of 0.01 to less than 15 dl/g s measured in tetralin at 135° C. and 100 parts by weight of a polyolefin comprising at least polypropylene, wherein the polyethylene is finely dispersed as particles with a number average particle diameter of, e.g., 1 to 5000 nm in the polyolefin comprising at least polypropylene. By virtue of the above constitution, the polypropylene composition has excellent transparency and rigidity, is free from the creation of a sweeper roll flow mark in the preparation of a film and substantially free from a neck-in phenomenon of a film, and has high productivity.

Abstract: The invention provides a process for producing polypropylene and/or random copolymers of propylene type using a stereoregular catalyst which comprises a titanium-containing solid catalyst component (A), an organoaluminum compound (B) and if required an organosilicon compound (C), wherein [I] before carrying out homopolymerization of propylene or random copolymerization of propylene with an &agr;-olefin other than propylene, the above component (A), an organoaluminum compound (B′) and if required an organosilicon compound (C′) are used, and a small amount of propylene or ethylene and/or an &agr;-olefin of 4-20 carbon atoms for pre-activation treatment is supplied to the above component (A), and [II] a catalyst which is prepared by adding an organosilicon compound (C″) to the pre-activated stereoregular catalyst in a molar ratio of 0.1-50 as Si/Ti, is used to produce polypropylene or propylene random copolymers.

Abstract: A metal-ceramic composite substitute is produced by joining a metal plate to a ceramic substrate by using a brazing material in a paste form prepared by adding 10-14 parts by weight of a vehicle to 100 parts by weight of a powder of which the solid centent comprises 90.0˜99.5% of an Ag powder, 0˜9.5% of a Cu powder and 0.5˜4.0% of an active metal powder, and 0.0˜0.9% of a titanium oxide powder if necessary.

Abstract: A metal-ceramic composite substitute is produced by joining a metal plate to a ceramic substrate by using a brazing material in a paste form prepared by adding 10-14 parts by weight of a vehicle to 100 parts by weight of a powder of which the solid centent comprises 90.0˜99.5% of an Ag powder, 0˜9.5% of a Cu powder and 0.5˜4.0% of an active metal powder, and 0.0˜0.9% of a titanium oxide powder if necessary.

Abstract: A polypropylene composition comprising 0.001 to 10 parts by weight of a polyethylene having an intrinsic viscosity [&eegr;E] of 0.01 to less than 15 dl/g s measured in tetralin at 135° C. and 100 parts by weight of a polyolefin comprising at least polypropylene, wherein the polyethylene is finely dispersed as particles with a number average particle diameter of, e.g., 1 to 5000 nm in the polyolefin comprising at least polypropylene. By virtue of the above constitution, the polypropylene composition has excellent transparency and rigidity, is free from the creation of a sweeper roll flow mark in the preparation of a film and substantially free from a neck-in phenomenon of a film, and has high productivity.

Abstract: The present invention provides a metallocene compound which produces an olefin polymer having a high molecular weight with a high stereoregularity.

Abstract: A polypropylene composition for the production of various molded articles which are excellent in moldability, mold shrinkage factor on molding, rigidity, flexibility, impact resistance, in particular low-temperature impact resistance, transparency, gloss, stress-whitening resistance, and the balance thereof; various molded articles having the above properties; a propylene composition which is suitable for a base resin for the polypropylene composition; and a process for the production thereof. The propylene composition comprises a propylene homopolymer and a propylene-ethylene copolymer, the intrinsic viscosity of the copolymer ([&eegr;]RC) is in the range of 1.7 to 2.8 dl/g, the intrinsic viscosity ratio of the homopolymer to the copolymer ([&eegr;]RC/[&eegr;]pp) is in the range of 0.7 to 1.

Abstract: In the present invention, a metal-ceramic composite substitute is produced by joining a metal plate to a ceramic substrate by using a brazing material in a paste form prepared by adding 10-14 parts by weight of a vehicle to 100 parts by weight of a powder of which the solid centent comprises 90.0˜99.5% of an Ag powder, 0˜9.5% of a Cu powder and 0.5˜4.0% of an active metal powder, and 0.0˜0.9% of a titanium oxide powder if necessary.

Abstract: An electronic circuit substrate including an aluminum-ceramic composite material having an electronic circuit formed on aluminum or an aluminum alloy plate of the aluminum-ceramic composite material which is prepared directly solidifying molten aluminum or an aluminum alloy on at least a portion of a ceramic substrate.

Abstract: A metal-ceramic composite circuit substrate having a ceramic substrate and a metal plate joined to at least one main surface of the ceramic substrate, the rate of voids formed on at least a joint surface at a semiconductor mounting portion of the metal plate per unit surface area being not more than 1.49%. The diameter of void formed on at least the joint surface at a semiconductor mounting portion of the metal plate is not larger than 0.7 mm. The surface undulation of the ceramic substrate is not more than 15 .mu.m/20 mm measured by a surface roughness tester in case that the ceramic substrate is joined directly to the metal plate. The metal plate is joined to the ceramic substrate through a brazing material containing at least one active metal selected from a group consisting of Ti, Zr, Hf and Nb. The ceramic substrate is at least one kind of ceramic substrate selected from a group consisting of Al.sub.2 O.sub.3, AlN, BeO, SiC, Si.sub.3 N.sub.4 and ZrO.sub.2.

Abstract: A paste of active metallic brazing material is applied to the entire surface of each side of aluminum nitride or alumina ceramic substrate 1; circuit forming copper plate 3 having a thickness of 0.3 mm is placed in contact with one surface of the substrate and a heat dissipating copper plate 4 having a thickness of 0.25 mm placed in contact with the other surface; the individual members are compressed together and heated at 850.degree. C.