Abstract:
A porous silicon carbide sinter and its production process, the sinter consisting mainly of silicon carbide and having a three-dimensional network structure composed mainly of silicon carbide plate crystals having an average aspect ratio of 3 to 50 and an average length along the direction of the major axis of 0.5 to 1,000 .mu.m, wherein the open pores in the network structure have an average sectional area of 0.01 to 250,000 .mu.m.sup.2.
Abstract:
A semiconductor device includes wiring boards each having an insulating board, conductor circuits and through-holes, the insulating board having top and bottom surfaces, the conductor circuits formed on the top and bottom surfaces, the through holes penetrating the insulating board and electrically connecting the conductor circuits of the top and bottom surfaces; conductor posts each having flange, head and leg portions, the flange portion having first and second surfaces and having an external diameter larger than that of the through-hole, the head portion protruding from the first surface, the leg portion protruding from the second surface; and electronic components each having an electrode formed on one or more surfaces and connected to the leg portion. The head portion is inserted until the first surface of the flange portion comes into contact with the bottom surface of the wiring board and electrically connected at an inner wall of the through-hole.
Abstract:
A multilayer printed wiring board is manufactured by a method in which a core substrate is provided, an insulation layer including a thermosetting resin material is formed over the core substrate, an uncured resin layer including a thermoplastic resin material is placed on the insulation layer, the uncured resin layer is cured to form a resin complex layer including a resin complex comprising the thermosetting resin material and the thermoplastic resin material, and a conductive circuit is formed over the resin complex layer.
Abstract:
An opening is formed in resin 20 by a laser beam so that a via hole is formed. At this time, copper foil 22, the thickness of which is reduced (to 3 μm) by performing etching to lower the thermal conductivity is used as a conformal mask. Therefore, an opening 20a can be formed in the resin 20 if the number of irradiation of pulse-shape laser beam is reduced. Therefore, occurrence of undercut of the resin 20 which forms an interlayer insulating resin layer can be prevented. Thus, the reliability of the connection of the via holes can be prevented. Thus, the reliability of the connection of the via holes can be improved.
Abstract:
This invention provides a printed wiring board having an intensified drop impact resistance of a joint portion between pad and solder. An electrode pad comprises pad portion loaded with solder ball and a cylindrical portion projecting to the solder ball supporting the pad portion. An outer edge of the pad portion extends sideway from a cylindrical portion so that the outer edge is capable of bending. If the outer edge bends when stress is applied to the solder ball 30, stress on the outer edge of the pad portion on which stress is concentrated can be relaxed so as to intensify the joint strength between an electrode pad and solder ball.
Abstract:
A solder resist comprising a thermosetting resin is printed on a surface of an insulating board (7) having a conductor circuit (6). The solder resist is then heat-cured to form an insulating film (1) having a low thermal expansion coefficient. A laser beam (2) is then applied to the portion of the insulating film in which an opening is to be formed, to burn off the same portion for forming an opening (10), whereby the conductor circuit (6) is exposed. This opening may be formed as a hole for conduction by forming a metal plating film on an inner surface thereof. It is preferable that an external connecting pad be formed so as to cover the opening. The film of coating of a metal is formed by using an electric plating lead, which is preferably cut off by a laser beam after the electric plating has finished.
Abstract:
An opening is formed in resin 20 by a laser beam so that a via hole is formed. At this time, copper foil 22, the thickness of which is reduced (to 3 μm) by performing etching to lower the thermal conductivity is used as a conformal mask. Therefore, an opening 20a can be formed in the resin 20 if the number of irradiation of pulse-shape laser beam is reduced. Therefore, occurrence of undercut of the resin 20 which forms an interlayer insulating resin layer can be prevented. Thus, the reliability of the connection of the via holes can be improved.
Abstract:
An opening is formed in resin 20 by a laser beam so that a via hole is formed. At this time, copper foil 22, the thickness of which is reduced (to 3 μm) by performing etching to lower the thermal conductivity is used as a conformal mask. Therefore, an opening 20a can be formed in the resin 20 if the number of irradiation of pulse-shape laser beam is reduced. Therefore, occurrence of undercut of the resin 20 which forms an interlayer insulating resin layer can be prevented. Thus, the reliability of the connection of the via holes can be improved.
Abstract:
The present invention provides a thin-film embedded capacitance having a substantial electrostatic capacity per unit area, and a method for manufacturing thereof.A thin film embedded capacitance comprising: a metallic thin-film for wiring made of a metallic material in a non-yield state; the first electrode formed on the film for wiring; a dielectric material layer formed on the first electrode and the film for wiring, at a temperature not lower than ordinary room temperature to lower than a yield temperature of the film for wiring, having a coefficient of thermal expansion lower than that the film for wiring; and the second electrode formed on the dielectric material layer, and a method for manufacturing thereof.
Abstract:
The present invention provides a thin-film embedded capacitance having a substantial electrostatic capacity per unit area, and a method for manufacturing thereof. A thin film embedded capacitance comprising: a metallic thin-film for wiring made of a metallic material in a non-yield state; the first electrode formed on the film for wiring; a dielectric material layer formed on the first electrode and the film for wiring, at a temperature not lower than ordinary room temperature to lower than a yield temperature of the film for wiring, having a coefficient of thermal expansion lower than that the film for wiring; and the second electrode formed on the dielectric material layer, and a method for manufacturing thereof.