Denso Corporation

Nippondenso Co., Ltd.

Toyota Jidosha Kabushiki Kaisha

Nippendenso Co., Ltd.

Nippondense Co., Ltd.

Masahito Imai

Tetsuo Fujii

Masaki Takakuwa

Tiaki Mizuno

Toshitaka Yamada

Hironobu Baba

Michitaka Hayashi

Takeshi Shinoda

Yasuki Shimoyama

Horonobu Baba

Yuichi Yokoyama

Hiroaki Tanaka

Yasutoshi Suzuki

Motomi Iyoda

Yukihiko Tanizawa

Kazuyoshi Nagase

Yoshifumi Murakami

Naohito Mizuno

Kenji Kanemaru

Makoto Hatanaka

Masahito Muto

Norio Kitao

Koichi Kamabora

Hirohito Shioya

Ryoichi Narita

Tokuhisa Nomura

Takushi Maeda

Akira Tai

Akiteru Takae

Akira Ishimaru

Haruyuki Ikeo

Hirohito Sioya

Munenari Kondo

Nobuyasu Gotou

A semiconductor mechanical sensor having a new structure in which a S/N ratio is improved. In the central portion of a silicon substrate, a recess portionis formed which includes a beam structure. A weight is formed at the tip of the beam, and in the bottom surface of the weight in the bottom surface of the recess portionfacing the same, an electrodeis formed. An alternating current electric power is applied between the weight portionand the electrodeso that static electricity is created and the weight is excited by the static electricity. In an axial direction which is perpendicular to the direction of the excitation of the weight, an electrodeis disposed to face one surface of the weight and a wall surface of the substrate which faces the same. A change in a capacitance between the facing electrodes is electrically detected, and therefore, a change in a physical force acting in the same direction is detected.

Semiconductor mechanical sensor

A sensor unit sensing a physical quantity comprises a first voltage evaluation circuit, a second voltage evaluation circuit, an alarm signal output circuit, and a sensor output circuit. The first voltage evaluation circuit evaluates a power voltage by comparing it with a reference voltage and outputs an accident signal when the power voltage is lower than a first predetermined voltage. The second voltage evaluation circuit working in a lower voltage range in which the first voltage evaluation circuit is insensitive outputs the accident signal when the power voltage is lower than a second predetermined voltage. The alarm signal output circuit outputs an alarm signal in response to the accident signal. The sensor output circuit outputs a sensor signal and inhibits the circuit from outputting the sensor signal in response to the accident signal, so that the alarm signal output circuit provides the alarm signal in response to the accident signal.

Unit for sensing physical quantity

A pressure sensor for detecting a pressure such as a brake oil pressure in an automobile is composed of a cylindrical stem, a sensor chip and a circuit board for processing an electrical signal from the sensor chip. The cylindrical stem includes a thin diaphragm formed at an axial end and an opening formed at the other axial end. The sensor chip is mounted on the diaphragm, and the circuit board is mounted on a flat side surface formed on the outer periphery of the cylindrical stem so that the circuit board is positioned perpendicularly to the sensor chip, thereby reducing a size of the pressure sensor in the radial direction of the stem. The pressure to be detected is introduced into the cylindrical stem from its opening, and the pressure is detected by the sensor chip mounted on the diaphragm.

Pressure sensor having sensor chip and signal processing circuit mounted on a common stem

A semiconductor mechanical sensor having a new structure in which a S/N ratio is improved. In the central portion of a silicon substratea recess portionis formed which includes a beam structure. A weight is formed at the tip of the beam, and in the bottom surface of the weight in the bottom surface of the recess portionfacing the same, an electrodeis formed. An alternating current electric power is applied between the weight portionand the electrodeso that static electricity is created and the weight is excited by the static electricity. In an axial direction which is perpendicular to the direction of the excitation of the weight, an electrodeis disposed to face one surface of the weight and a wall surface of the substrate which faces the same. A change in a capacitance between the facing electrodes is electrically detected, and therefore, a change in a physical force acting in the same direction is detected.

A first end of each hollow stem includes a diaphragm and a strain gauge, and a second end of each stem includes an opening. A housing includes a plurality of stem receiving through holes, each of which receives the corresponding stem. An O-ring is arranged in each through hole such that the O-ring is placed adjacent an end surface of the second end of the stem, which is axially inwardly spaced from a surface of the side of the housing. When the stems and the housing are integrally installed over the device under test, each O-ring seals between the end surface of the second end of the corresponding stem and the device under test.

Pressure sensor apparatus including stems provided with strain measuring arrangement

A case of a pressure sensor has an atmospheric pressure introduction port for introducing atmospheric pressure into the case, and a water repellent filter that is attached to the atmospheric pressure introduction port to prevent passage of moisture, dust and the like while allowing flow of air. The filter is disposed to have a filter surface extending along a gravitational direction when the pressure sensor is used.

Pressure sensor with water repellent filter

A semiconductor sensor chip mounted on a thin diaphragm of a cylindrical metallic stem via an insulation layer is hermetically contained in a housing of a pressure sensor. The sensor chip includes a strain gage for outputting an electrical signal according to distortion of the diaphragm caused by pressure to be measured. A shield layer is interposed between the insulation layer and the sensor chip, and the shield layer is grounded. Influence of outside noises on the sensor outputs is eliminated or suppressed by the grounded shield layer even if the outside noises are in a high frequency region.

Pressure sensor having semiconductor sensor chip

A pressure sensor has a sensor element portion for detecting pressure, and a pressure conduction portion connectable to a detected member and defining therein a conduction passage for conducting pressure from the detected member to the sensor element portion. A protective cap is detachably attached to the pressure conduction portion to cover a sealed portion where the pressure conduction portion is to be sealed to the detected member until before the pressure sensor is connected to the detected member. The protective cap has an opening portion through which the conduction passage communicates with an outside thereof. Accordingly, pressure characteristics can be checked without detaching the protective cap from the pressure conduction portion.

Pressure sensor and method for assembling the same

A semiconductor mechanical sensor having a new structure in which a S/N ratio is improved. In the central portion of a silicon substrate a recess portion is formed which includes a beam structure. A weight is formed at the tip of the beam, and in the bottom surface of the weight in the bottom surface of the recess portion facing the same, an electrode is formed. An alternating current electric power is applied between the weight portion and the electrode so that static electricity is created and the weight is excited by the static electricity. In an axial direction which is perpendicular to the direction of the excitation of the weight, an electrode is disposed to face one surface of the weight and a wall surface of the substrate which faces the same. A change in a capacitance between the facing electrodes is electrically detected, and therefore, a change in a physical force acting in the same direction is detected.

A semiconductor mechanical sensor having a new structure in which a S/N ratio is improved. In the central portion of a silicon substrate , a recess portion is formed which includes a beam structure. A weight is formed at the tip of the beam, and in the bottom surface of the weight in the bottom surface of the recess portion facing the same, an electrode is formed. An alternating current electric power is applied between the weight portion and the electrode so that static electricity is created and the weight is excited by the static electricity. In an axial direction which is perpendicular to the direction of the excitation of the weight, an electrode is disposed to face one surface of the weight and a wall surface of the substrate which faces the same. A change in a capacitance between the facing electrodes is electrically detected, and therefore, a change in a physical force acting in the same direction is detected.

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Chita, Japan

Masahito Imai