Hitachi, Ltd.

Hitachi Cable, Inc.

Ryosaku Kanzawa

Hideo Sato

Kazuji Yamada

Kanji Kawakami

Shigeyuki Kobori

Kazuo Kato

Satoshi Shimada

Takao Sasayama

Minoru Takahashi

Ryoichi Kobayashi

Seiko Suzuki

Motohisa Nishihara

Hitoshi Minorikawa

Ken Takahashi

Kazuhiro Kurata

Hisumi Sano

A monolithic light emitting diode array includes: at least one mixed crystal layer formed on a substrate by an epitaxial growth to provide a P-N junction at the boundary surface thereof; row of a plurality of light emitting diode portions each having the P-N junction; at least one forward mesa etching groove provided along the row of a plurality of light emitting diode portions on the at least one mixed crystal layer; a plurality of reverse mesa etching grooves provided so to be orthogonal to the at least one forward mesa etching groove and positioned between the plurality of light emitting diode portions on the at least one mixed crystal layer; a plurality of individual electrodes having electrode portions extending respectively to the plurality of light emitting diode portions so as to cross the at least one forward mesa etching groove, and a common electrode provided on a back surface of said substrate. Each of the emitting diode portions is surrounded by the forward and reverse mesa etching grooves so that the manufacturing thereof becomes easier and the characteristic thereof is improved.

Monolithic light emitting diode array

A pressure transducer is disclosed comprising a pressure sensor portion having gage resistors in bridge formed on a thin diaphragm of a semiconductor substrate, and a power supply connected to the pressure sensor portion for driving the pressure sensor. The power supply includes a first current source for supplying a temperature-dependent current equivalent to the sum of a current almost proportional to the absolute temperature and a current independent of temperature, and a second current source for sinking the current almost proportional to the temperature characteristic of the gage resistors from the current of the first current source. A temperature compensation circuit is additionally provided to drive the bridge circuit by the difference between the temperature-dependent current and the current proportional to the temperature characteristic in a constant-current driving mode, and by a voltage proportional to the current difference when the output of the bridge circuit is connected to an amplifier whose gain is dependent on temperature.

Pressure transducer with temperature compensation circuit

In an integrated pressure sensor, a silicon chip for pressure detection and a substrate for supporting the silicon chip are made of the same material, the silicon chip has a thin diaphragm portion and a peripheral fixed portion thicker than the diaphragm portion, and the silicon chip is bonded to the substrate through a thin insulating film.

Integrated pressure sensor

A semiconductor pressure transducer assembly comprising a silicon diaphragm assembly and a glass covering member. The silicon diaphragm assembly has a circular diaphragm portion of thin silicon which is formed using etching, and a thick supporting portion therearound. Piezoresistive elements of a piezoresistive bridge circuit and conducting paths for electrically connection thereof are formed on the silicon diaphragm assembly. On a surface of the silicon diaphragm assembly, a passivating layer of silicon dioxide are formed in uniform thickness, and further on a surface of the passivating layer is formed a layer of polysilicon on the supporting portion of the silicon diaphragm assembly. In the passivating layer, a contacting window is formed, through which the polysilicon layer is electrically connected to the silicon diaphragm assembly. The covering member of borosilicate glass having a circular well is mounted and bonded onto the silicon diaphragm assembly in contact with the polysilicon layer using Anodic Bonding method. And the processed silicon diaphragm assembly has a flat surface thereof, on which the piezoresistive elements and the conducting paths are constructed using Ion Implantation method, or reforming a silicon dioxide layer thereon after removing another silicon dioxide layer used as mask in diffusing process.

Semiconductor absolute pressure transducer assembly and method

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Ibaraki, Japan

Ryosaku Kanzawa