Fuji Electric Co., Ltd.

Sumitomo Metal Ceramics Inc.

Shigemasa Saito

Masaharu Nishiura

Akira Morozumi

Katsumi Yamada

Seiji Imamura

Tomio Shimizu

Toshio Nozaki

Mamoru Akimoto

Mitsuo Sunaga

Hisashi Fujitaka

Seigo Oiwa

Kazuo Kondo

Shizuyasu Yosida

Katumi Yamada

Hiroshi Miyama

Kazuya Matuura

Kazuhiko Teramura

A fire retardant multilayered printed wiring board without halogen compounds, having enhanced thermal conductivity of insulator layers to prevent electronic components from being damaged during soldering. The insulator layers are formed of a glass cloth impregnated with an epoxy resin composition. Metal foil layers, in each of which a circuit is formed, are laminated alternately with the insulator layers. The epoxy resin composition includes at least phosphate ester, aluminum hydroxide, silica, calcium oxide, strontium titanate, and iron oxide. Inorganic components are provided in the insulator layers as about 8% to about 18% by mass of P O , about 20% to about 28% by mass of Al O , about 0.1% to about 0.6% by mass of SiO , about 0.1% to about 1.0% by mass of Cl, about 15% to about 20% by mass of CaO, about 0.3% to about 0.5% by mass of TiO , about 0.2% to about 0.4% by mass of Fe O , and about 0.1% to about 0.3% by mass of SrO, in converted values as measured by an X-ray fluorescence analysis.

Multilayered printed wiring board

A Ceramic Bonding Copper (CBC) substrate used in semiconductor modules includes a ceramic plate having foil-shaped copper plates bonded to the ceramic plate by the direct copper bonding method. A circuit pattern is formed on one of the copper plates. The ceramic plate is fabricated by sintering at high temperature an alumina powder compact containing zirconia and one or more of the following additives: yttria, calcia, magnesia, and ceria. The flexural strength and the thermal conductivity of the alumnina ceramic plate of the invention are remarkably improved, facilitating a reduction in the thickness of the ceramic plate. The reduction in thickness of the CBC substrate further improves the ability of the semiconductor device to radiate heat and therefore increases the current carrying capability of the semiconductor device.

Insulation substrate for a semiconductor device

A ceramic substrate is a high-temperature fired body consisting of alumina as the main component, zirconia, and a ceramics sintering assisting agent. The assisting agent is one of yttria, calcia, magnesia, and ceria, in which yttria is added at 0.1-2 wt %, calcia is added at 0.02-0.5 wt %, magnesia is added at 0.02-0.4 wt %, and ceria is added at 0.02-0.5 wt %.

Zirconia-added alumina substrate with direct bonding of copper

A disk storage device includes a fixed information storage disk that is free from deformation, has a wide effective data storage area and shows excellent anti-mechanical shock properties. Specifically, a disk hole of the information storage disk is fit to a hub coupled to a rotary shaft of a spindle motor until the disk contacts with a flange face of the hub. The spindle motor and the disk are then sandwiched by a lower electrode which contacts with the bottom surface of the spindle motor and an upper electrode which contacts with the upper surface of the disk. A DC power supply applies positive potential to the hub via the lower electrode and the casing of the spindle motor and negative potential to the disk via the upper electrode. An electrostatic junction portion is formed between the bottom face of the disk and the flange face of the hub, thereby securing the disk tightly to the hub.

Disk storage device with electrostatically bonded information storage

An oil dashpot and a method of producing the oil dashpot pole piece in an electromagnetic tripping apparatus from steel wire rod, wherein the steel wire rod contains phosphorus and sulfur in quantities less than 0.1 percent by weight and wherein the particle size of ferrite in a metal texture of the steel wire rod is between 7 and 8 micrometers, comprising the steps of aligning a predetermined length of steel wire rod in holding die, to form a pole piece first diameter portion and a second diameter portion. In addition, a method of producing an oil dashpot, comprising a cylinder having a body portion and a flange portion and a pole piece having a first diameter and a second diameter portion, comprising the steps of fitting the pole piece onto the cylinder such that the first diameter portion is placed within an opening in the body portion of the cylinder and the second diameter portion abuts the flange portion of the cylinder to form a junction, pressing the pole piece against the cylinder such that a predetermined force is applied to the junction between the second diameter portion and the flange portion, heating the junction by a predetermined temperature such that interdiffusion occurs between the second diameter portion and the flange portion, whereby the cylinder is sealed.

Method of making an oil dashpot in an electromagnetic tripping apparatus

The method of bonding silver-based contact is disclosed. A silver-based contact is brought into contact with a support, at least the surface of which is made of a cupreous material, with a pressure of less than 1 kgf/cm.sup.2 exerted therebetween. The contact and support are heated in a non-oxidizing atmosphere at a temperature of more than 700.degree. C.

Method for bonding silver-based contact

A contact member for a switching device is formed by soldering a contact tip to a movable contact member. The movable member is formed from an age-hardenable copper alloy that has been subjected in series to solution treatment, half age-hardening, grinding and rust-prevention coating.

Method of manufacturing a movable contact member

A method of manufacturing stationary electromagnetic cores utilizes mild steel having a carbon content of up to 0.01% by weight and an impurity content of less than 0.31% by weight. Use of this material lowers the cost of manufacturing electromagnetic cores by shortening the drawing process and obviating the necessity for magnetic annealing.

Growing community of inventors

Kanagawa, Japan

Shigemasa Saito