Abstract: A hot press for producing a multilayered substrate including vertically opposing upper and lower bolsters relatively movable toward each other to press multilayered substrate blanks and to cool the plates after the bonding. A sealing arrangement includes a cylinder and encloses the upper and lower bolsters so as to define a hermetically sealed space, with an evacuating arrangement reducing the pressure inside the hermetically sealed space during heating and pressing in which a bonding agent in the multilayered substrate blanks is softened. A high-pressure gas supplying arrangement supplies a pressurizing gas into the hermetically sealed space so as to impart the bonding pressure.

Abstract: The present invention provides a printed circuit board which is high in acid resistance, mechanical strength at high temperature and bond strength, a method for making the printed circuit board and an apparatus used for making the printed circuit board. The technique of the present invention is characterized in that a metallic film having metal particles discretely distributed therein is provided on a roughened surface of copper circuit pattern on an insulating substrate which has been oxidized to form copper oxide and thereafter reduced.

Abstract: A hot press including a displaceable sleeve for surrounding materials of a multi-layer substrate under a reduced pressure condition, a gas pressurizing condition and a heating condition with thermal plates. Upper and lower sealing units seal an interior of the sleeve, with a mechanism lowering and raising the sleeve. A pilot check mechanism prevents a lower bolster from raising/lowering upon the reduced pressure condition and the gas pressure condition, and a retainer maintains the lowered or raised condition of the sleeve. The multi-layer substrate is formed under the reduced pressure condition and the gas pressure condition. Accordingly, the atmosphere and moisture between the materials of the multi-layer substrate and volatile composition are removed. Additionally, a void generated during the heat and pressure process by the heating plates is eliminated from the multi-layer substrate.

Abstract: A circuit board, which comprises an insulating substrate, a copper wiring having a coarsely roughened surface provided on the insulating substrate, and a copper oxide-reduced layer provided on the coarsely roughened surface of the copper wiring and formed by reduction of copper oxide and electroless plating, the copper oxide-reduced layer having a finely roughed surface and having a deposited layer of at least one of nickel and cobalt, where the copper oxide-reduced layer having a deposited layer of at least one of nickel and cobalt on the surface is roughened in a range of 0.05 to 5 .mu.m in terms of a maximum vertical distance between the top of convex parts and the bottom of concave parts of the copper oxide-reduced layer per .mu.m of the longitudinal distance of the copper oxide-reduced layer, and at least one of nickel and cobalt is deposited in an amount of 5.times.10.sup.-7 to 1.times.10.sup.-4 g/cm.sup.2 on the copper oxide-reduced layer, has a high adhesiveness to an insulating resin.

Abstract: To make a composite article comprising a copper element and an adhesive material adhesively bonded to a surface thereof, the surface of the copper element is provided with knife-shaped elongate projections whose opposite flanks are at an average angle of less than 60.degree. to each other. The knife-shaped elongate projections may include rod-shaped projections much smaller than the knife-shaped projections projecting outwardly from the surface of the knife-shaped projections. The knife-shaped projections may be formed by electroless plating and the rod-shaped projections by oxidation and optionally reduction. Bonding strength is improved.

Abstract: A method of bonding copper and a resin together is disclosed which comprises forming a copper oxide layer on the surface of copper to be bonded to a resin, reducing the copper oxide layer to metallic copper with a reducing solution, and bonding the metallic copper and the resin together. According to this method, a good acid resistance of the bonding interface and a sufficiently high bonding strength can be obtained.