Hitachi, Ltd.

Kazuo Hirota

Yutaka Akiba

Toshio Futami

Tatsuo Hamamoto

Nobuo Kishiro

Ryohei Satoh

Koji Suzuki

Kunio Matsumoto

Takashi Maruyama

Akira Murata

Takaji Takenaka

Hitoshi Yoshidome

Masao Mitani

Tsutomu Hara

Susumu Kasukabe

Munehisa Kishimoto

Tsuyoshi Fujita

Suguru Sakaguchi

Makoto Iida

Akio Fujiwara

Toshihiko Ohta

Hideki Watanabe

Muneo Oshima

Toshinori Ameya

Fumiuki Kobayashi

Hironobu Okino

An apparatus comprises a condenser such as a condenser for reducing power source noise to be implemented on a board, a conductor for supplying a current passing through the condenser, and a current path comprising conductors and components which are installed in the neighborhood of at least one of the condenser and conductor and the effective inductance component of the condenser is reduced by passing a current through the current path in the phase opposite to that of a current passing through the condenser and conductor.

Inductance cancelled condenser implemented apparatus

A shielding method which utilizes a three dimensional structure and is effective to a source of the electromagnetic radiation noise, and a circuit board employing the same are obtained. Further, for the purpose of making the shielding function at an enclosure level unnecessary and realizing the recycling of enclosure materials by using this circuit board, in a circuit board structure having at least a signal layer, a power source layer and a ground layer, a signal line on the signal layer which is sandwiched between the two conductor layers made up of the power source layer and the ground layer, or the power source layers or the ground layers, is enclosed in a three dimensional manner with the conductor layers, thereby to form a single or double electrical closed loop current path or paths. By adopting this structure, there is obtained the effect that the electromagnetic radiation noise radiated from the circuit board is greatly reduced. In addition, as a result, there is obtained the effect that since the shielding processing required for the enclosure becomes unnecessary, the enclosure materials can be recycled.

Shielding method and circuit board employing the same

The present invention relates to a mounting structure adapted to be mainly used commercially and to an electronic device employing such mounting structure. A board carrying a plurality of chips is directly coated with resin to form a casing or a part thereof. Alternatively a plurality of the boards interconnected by flexible wiring sheets and coated with resin with retaining the flexibility of the wiring sheets. Such structure helps to provide a handy electric device which is required to be compact, light-weight and thin.

Mounting structure and electronic device employing the same

Disclosed is an electronic circuit device in which the solder (14) connecting lead pins (6) to the ceramic substrate (2) has a melting point of 356.degree. C. to 450.degree. C. and has a tensile strength being low in such an extent that a thermal contraction stress generated in a cooling process of the solder (14) from the melting point thereof is low and the substrate (2) does not break. The solder (14) is a Au-Ge alloy containing 10-15 wt % of Ge. Electronic circuit devices, which employ the above solder (14) in the connections, are free from damages in the ceramic wiring substrate (2) due to the bonding. Further, when the electronic circuit device undergoes a series of assembly processes after the above bonding, such solder (14) does not melt, and wettability of such solder (14) is favorable.

Electronic circuit device provided with a ceramic substrate having lead

According to one embodiment of the present invention, a magnetic bubble memory module comprising a flexible printed circuits substrate (FPC3), on which a magnetic bubble memory chip (CHI) is mounted and electrically connected, with interconnecting patterns (9a) electrically connecting the chip (CHI) with external connecting leads, terminals or pins as well as bias coil winding (BIC2) for applying bias field to the chip (CHI), thereby reducing the number of components as well as fabricating steps because of the formation of the bias coil (BIC2) with the printed circuits substrate (FPC3).

Magnetic bubble memory module with interconnection member

According to one embodiment of the present invention, a magnetic bubble memory module comprising a flexible printed circuits substrate (FPC3), on which a magnetic bubble memory chip (CHI) is mounted and electrically connected, with interconnecting patterns(9a) electrically connecting the chip (CHI) with external connecting leads, terminals or pins as well as bias coil winding (BIC2) for applying bias field to the chip (CHI), thereby reducing the number of components as well as fabricating steps because of the formation of the bias coil (BIC2) with the printed circuits substrate (FPC3).

A probe head for use with equipment for testing a semiconductor device such as a large scale integrated circuit (LSI) includes electrode pads are formed on a circuit substrate, and a pad protecting conductive layer formed on the pads. A probe pin forming material is grown which is worked into a pin-like configuration, thereby improving a pin assembling property of a probe head portion and this realizes highly accurate pinning with high reliability.

Method of manufacturing probing head for testing equipment of

A magnetic bubble memory chip is disposed at a position surrounded by a rectangular annular core having two pairs of opposite sides wound by a pair of wires, respectively, and is covered by a case for confining revolving magnetic field, thereby providing a revolving magnetic field to said chip. A bubble memory includes a permament magnet used as a holding magnetic field source, lying at a predetermined angle to the chip. An inclination between the chip and the magnet is provided on the revolving-magnetic-field confining case to be inserted between the chip and the magnet by having the case changed in plate thickness.

Magnetic field confirming case with inclined portions for magnetic

A circuit board including resistors on one surface of a board or substrate having through hole conductors arranged in a lattice like fashion. At least one electrode is formed on a surface of the resistors, at least one electrode being formed by removing a portion of a surface of the board or substrate coaxially with the through hole conductors thereby forming substantially disk-shaped resistors.

Circuit board

A magnetic bubble memory module having a rectangular core shaped like a picture frame providing windings on respective two pairs of opposite sides, at least one magnetic bubble memory chip disposed in an area surrounded by the core, a flexible substrate having a chip-loading section for loading the magnetic bubble memory chip thereon and having four corners for leading out lead wires connecting signal lines and driving lines of the chip. A revolving magnetic field-confining case accommodates the core, the chip and the flexible substrate and enables the lead wires of the flexible substrate at the corners of the chip-loading section to be drawn out therethrough.

Magnetic bubble memory module

In connecting an electronic circuit part such as a semiconductor or other part to a substrate for mounting the part with solder, the solder is composed of a high-melting-point solder portion which is subjected to working such as rolling and heat treatment in order to break the cast structure thereof, and a smaller volume of low-melting-point solder portions. The high-melting-point solder portion is connected to both the electronic circuit substrate and the electronic circuit part through the low-point-melting solder portions. This method enables interconnection between objects to be connected without impairing the high ductility and toughness of the high-melting-point solder which is subjected to working and heat treatment. This soldering method ensures highly reliable manufacture of miniaturized high density circuits, such as LSI.

Electronic circuit device and method of producing the same

In a magnetic bubble memory unit comprising two pairs of windings confronting in parallel each other, a printed circuit board having a magnetic bubble memory chip thereon surrounded by the windings for providing the rotating magnetic field, and a conductive shield case for covering the magnetic bubble memory chip on the printed circuit board, slitlike openings are provided on the side face of the conductive shield case so as to present connection between the printed circuit board and an external device.

Magnetic bubble memory unit

A magnetic bubble memory device comprises a cassette and a body. The cassette has a bias magnetic field generator adapted to generate a bias magnetic field for sustaining magnetic bubbles within a bubble memory chip and is removed of coils adapted to generate a rotating magnetic field for propagation of the magnetic bubbles. The body has a rotating magnetic field generator. The cassette is mounted to or dismounted from the body. When the cassette is dismounted from the cassette, information stored in the chip is held by the bias magnetic field generator and when the cassette is mounted to the body, information is read from or written into the chip by the rotating magnetic field generator.

Magnetic bubble memory device

A magnetic bubble memory module comprises a shielding conductor case which encloses therein an annular rectangular parallelepiped core having windings and a magnetic bubble memory chip arranged in a space defined by the annular core. The central portion of the shielding conductor case is recessed so that it is brought near the bubble memory chip. The recess may be formed in one or each of the top and bottom surfaces of the shielding conductor case. A magnet plate is disposed in the recess of the shielding conductor case. The whole assembly is covered by a magnetic shielding case.

A litz wire comprises three or more insulated strands consisting essentially of an inner conductor and an outer insulating layer on said conductor. The strands are twisted symmetrically with respect to the center line of the wire, so that a current density distribution in the litz wire becomes uniform. Three or more such litz wires are twisted to form a composite litz wire. The composite litz wires are suitable for use in a high-frequency coil.

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Chigasaki, Japan

Kazuo Hirota