Hitachi, Ltd.

Hitachi Automotive Engineering Co., Ltd.

Hitachi Car Engineering Co., Ltd.

Masayuki Miki

Masahiro Matsumoto

Seiko Suzuki

Takao Sasayama

Shigeki Tsuchitani

Seikou Suzuki

Nobuaki Miyakawa

Satoshi Shimada

Shinichi Sakamoto

Matsuo Amano

Sadayasu Ueno

Norio Ichikawa

Hiromichi Ebine

Akira Koide

Masayoshi Suzuki

Masanori Kubota

Yoshihiro Yokota

Toshitaka Suzuki

Seikoo Suzuki

Keiji Hanzawa

Shinya Sato

Kazuo Sato

Kazuo Kato

Toshio Ishii

Yoshishige Oyama

Akira Ikegami

Yutaka Nishimura

Nobuo Sato

Seiji Suda

Atsushi Miyazaki

Shotaro Naito

Yasunori Mouri

Masahiro Komachiya

Minoru Osuga

Takeshi Hirayama

Kanemasa Sato

Susumu Murakami

Tomoyuki Tanaka

Yoshiyuki Sasada

Takayuki Itsuji

Masumi Imai

Shigeyuki Kobori

Toru Sugawara

Yasuhiro Asano

Shinichi Yamaguchi

Masahiro Kurita

Yukiko Sugisawa

Seikoh Suzuki

Benjamin Kloeck

Yukiko Kawai

Nobukai Miyakawa

An acceleration sensor is disclosed which includes a capacitance-type acceleration detection element mounted on a ceramic base plate. The element comprises a movable electrode mounted between a pair of fixed electrodes. Acceleration of the sensor in a measurement direction causes the movable electrode to move relative to the fixed electrodes and the element has opposite ends in a direction perpendicular to the measurement direction. The acceleration detection element is mounted on the base at a first one of the opposite ends. Accordingly, the mounting surface of the acceleration sensor is parallel to the direction of acceleration to be detected. Thus the acceleration sensor can be surface-mounted on a printed board, and more be easily mounted in an automobile air bag control system or the like.

Structure for mounting components

Acceleration sensor

Surface mount type package unit

A pressure sensor superior in pressure resistance and capable of covering from a low to high pressure range as a measuring range is to be provided. Plural pressure sensing sections for high and low pressures are formed on a silicon board, the pressure sensing sections each com ing an outer frame portion, a diaphragm portion, a strain gauge portion and an electrode portion. The silicon board side with the strain gauge portions formed thereon and an insulating substrate having electrode take-out portions are bonded together in such a manner that the strain gauge portions are hermetically sealed and that the electrode portions on the silicon board and the electrode take-out portions of the insulating substrate are electrically connected with each other, to constitute a pressure sensing unit. The pressure sensing unit, a low-melting glass and a stem are laminated together in such a manner that lead pins are electrically bonded by solder to the electrode portions of the silicon board through the electrode take-out portions of the insulating substrate. In this state, the low-melting glass is melted to bond the pressure sensing unit and the stem with each other.

Semiconductor type pressure sensor

A combustion pressure sensor suitable for a highly precise combustion control system of an automobile engine and a sensing system using the sensor. The combustion pressure sensor includes a SOI substrate having a three-layered structure of a first silicon plate, a thermal oxide film, and a second silicon plate, wherein a combustion pressure is sensed on the basis of a pressure or a force applied to the first silicon plate.

Semiconductor-type pressure sensor with sensing based upon pressure or

A capacitance detector comprises switches for charging and discharging a sensing part, an integrator constituted by a condenser and an operational amplifier for integrating a charging current or a discharging current which is generated according to the charging and discharging the sensing part, a switch for charging an output voltage of the operational amplifier and for feedbacking an electric charge to the integrator, and a condenser. The capacitance detector can be provided by the operational amplifier having a low response performance and a small output current and no hold sample circuit, thereby a circuit scale of the capacitance type sensor can be made small.

Capacitance type sensor device

A capacitance type accelerometer, having a fist silicon plate formed a movable electrode which is moved according to acceleration, two second silicon plates which are disposed on both sides of the first silicon plate with a certain separation distance, and thermal oxide films which are respectively disposed between the first silicon plate except the movable electrode and the two second silicon plates and stick the first silicon plate except the movable electrode and the two second silicon plates together. And further, a capacitance type accelerometer, having, a silicon plate formed a movable electrode which is moved according to acceleration, glass plates respectively mounting a conductive layer thereon which are opposite to the silicon plate with a certain separation distance and are sticked to the both side of the silicon plate except the movable electrode and leeding wires which are respectively connected to the conductive layers through a groove formed between the silicon plate and the glass plates respectively deriving. These capacitance type accelerometers are made by processing and cutting a wafer by dicing saw without coming into the accelerometer of cutting chips or cutting water.

Capacitance type accelerometer

A semiconductor acceleration sensor is formed by a cantilever having a conductive movable electrode of predetermined mass at one end, at least one pair of fixed conductive electrodes which are stationary with respect to the movable electrode located on opposing sides of the movable electrode, and gaps provided between the movable electrode and the fixed electrodes. To prevent the movable electrode becoming fused to the contacted fixed electrode, in a first aspect of this invention, an insulating layer is provided between the movable electrode and fixed electrodes, the layer being either on the movable electrode or on the fixed electrodes and in a second aspect the movable electrode or, preferably, the fixed electrodes, are formed of a high melting point material. In such a second aspect, to improve adhesion between the high melting point material and a substrate to which the fixed electrodes are mounted, a lower melting point material is firstly coated on the substrates. A sensor detector unit processing circuit has the output characteristic of the circuit digitally adjusted by suitable switching of a plurality of resistors, and the sensor chip and the detector unit integrated circuit may be located on a common base and mounted in a hermetically sealed chamber to prevent adverse environmental effects affecting operation of the sensor and detector unit assembly. A gas having a dew point of -40.degree. C. or lower is, advantageously, charged into the hermetically sealed chamber.

Semiconductor acceleration sensor and vehicle control system using the

A capacitance type accelerometer, having a fist silicon plate formed a movable electrode which is moved according to acceleration, two second silicon plates which are disposed on both sides of the first silicon plate with a certain separation distance, and thermal oxide films which are respectively disposed between the first silicon plate except the movable electrode and the two second silicon plates and stick the first silicon plate except the movable electrode and the two second silicon plates together. And further, a capacitance type accelerometer, having, a silicon plate formed a movable electrode which is moved according to acceleration, glass plates respectively mounting a conductive layer thereon which are opposite to the silicon plate with a certain separation distance and are sticked to the both side of the silicon plate except the movable electrode and leading wires which are respectively connected to the conductive layers through a groove formed between the silicon plate and the glass plates respectively deriving. These capacitance type accelerometers are made by processing and cutting a wafer by dicing saw without coming into the accelerometer of cutting chips or cutting water.

An electrostatic type micro accelerometer comprising means for preventing permanent sticking between a movable electrode and a stationary electrode due to residual dielectric polarization, resisual electric charges and water adsorption and condensation around possible contacting portions therebetween when the movable electrode excessively displaces. The sticking preventing means is realized by disposing one of electric field reducing means, water adsorption and condensation reducing means and contacting area limiting means around the possible contacting portions.

Electrostatic type micro transducer and control system using the same

A signal processor (5) is coupled to a detector (6) for detecting a physical quantity. The signal processor has a zero adjustment memory (14) and a sensitivity adjustment memory (16). The zero adjustment memory and the sensitivity adjustment memory have a number of switches (20, 20A, 20', 20'), respectively. These switches are changed over digitally using a zener zapping method or a polysilicon fuse method at each switch to adjust the characteristics of the detector.

Sensor

In a capacitance type accelerometer used for an air bag system etc., a plurality of grooves crossing each other are provided on the surface of a movable electrode which is arranged to face a fixed electrode at a portion having a gap thereinbetween, and end portions of each groove open to an outside space at the portion between the movable electrode and the fixed electrode. The grooves can be provided on surface of the fixed electrodes. Ventilation between inside and outside of the facing portion is improved by opening of the grooves to outside space, and air damping which is caused at operation of the movable electrode at the gap between the electrodes is reduced, and, consequently, response speed of the movable electrode is increased.

Capacitance type accelerometer for air bag system

A capacitive type semiconductor accelerometer has an intermediate silicon plate of n type conductivity including a movable electrode constituting a pendulum mass formed within the intermediate silicon plate and supported thereby via a beam so as to permit movement in a direction perpendicular to its plane. A first conductive island is formed within the intermediate plate and is immovably supported thereby via a first insulating leg so as to be isolated therefrom, and an upper glass plate is anodic bonded to the intermediate silicon plate. A first stationary electrode is formed on the upper glass plate at the position facing one face of the movable electrode with a predetermined gap. A lower glass plate is anodic bonded to the intermediate silicon plate and a second stationary electrode is formed on the lower glass plate at the position facing the other face of the movable electrode with a predetermined gap. First, second and third pads are disposed in common on the lower glass plate at the outside of the intermediate silicon plate, the first pad being electrically connected to the first stationary electrode via a first thin film lead formed on the lower glass plate and the first conductive island, the second pad being electrically connected to the movable electrode via a second thin film lead formed on the lower glass plate and the intermediate silicon plate and the third pad being electrically connected to the second stationary electrode via a third thin film lead formed on the lower glass plate.

Capacitive type semiconductor accelerometer

Growing community of inventors

Katsuta, Japan

Masayuki Miki