Abstract: The invention provides a humidity-sensitive element using, as a humidity-sensitive film, a polyimide having a molecular structure capable of forming a network structure at a high density, exhibiting less drift after being left standing at a high temperature and a high humidity and having excellent characteristics. A humidity-sensitive element according to the invention uses the polyimide obtained by dehydrating and ring closing a polyamide acid forming a network structure in which terminals of basic molecular chains are interconnected with one another, as a humidity-sensitive film. The humidity-sensitive element of the invention suitably uses a polyimide, in which terminals of basic molecular chains are interconnected with one another by use of triamine or a tricarboxylic acid, as a humidity sensitive film.

Abstract: A pressure sensor is attached to an engine by inserting a cylindrical metal case having a hollow part into an attaching hole formed in the engine in which engine oil flows. An oil passage is formed in the cylindrical metal case, and oil passages are formed in the housing. The pressure sensor is connected to the engine through an oil transmitting pipe and an oil returning pipe in order to radiate thermal energy of a pressure sensing diaphragm and a pressure sensing chip by flowing the engine oil from the engine to the hollow part of the metal case and by returning the engine oil from the hollow part to the engine.

Abstract: The pressure sensor of the type having a pressure transmitting member transmitting a pressure received by a pressure-receiving diaphragm to a sensor chip is provided with a heat radiating member. This heat radiating member substantially suppresses the heat transferring from the pressure-receiving diaphragm to the sensor chip, to thereby preventing the pressure sensor from malfunction.

Abstract: A pressure sensor has a diaphragm with a first layer and a second layer, a pressure transmitting member being in contact with the second layer, and a sensing element. The diaphragm is deformable in response to a pressure applied on a front surface of the first layer. The transmitting member transmits this pressure to the sensing element. The sensing element detects the pressure. A heat applied to the diaphragm induces the layers to be shifted toward the transmitting member or the opposite side of the transmitting member due to a shape of the diaphragm. The layers of the diaphragm have thermal expansion coefficients differing from each other. A thermal deformation of the layers caused by the thermal expansion difference between the layers cancels out the thermal deformation of the layers originated in the shape of the diaphragm.

Abstract: A pressure sensor is provided which may be employed in measuring the combustion pressure in an internal combustion engine. The pressure sensor is equipped with a pressure sensing diaphragm assembly which includes a first diaphragm, a second diaphragm, and liquid or gel. The first diaphragm is flexible when exposed to pressure to be measured and joined to the second diaphragm to define a closed chamber filled with the liquid or gel to transmit the pressure to the second diaphragm. A pressure transmitting member is disposed in abutment with the second diaphragm to transmit the pressure, as transmitted from the first diaphragm, to a pressure sensing device. The inclusion of the liquid or gel in the closed chamber between the first and second diaphragms results in an increase in heat capacity of the diaphragm assembly to decrease the thermal distortion thereof without sacrificing the sensitivity of the pressure sensor.

Abstract: The pressure sensor includes a first tubular member including at one end portion thereof a sensing section outputting an electrical signal indicative of a pressure applied thereto, and an opening section formed at the other end portion thereof, a second tubular member including an opening section formed at one end portion thereof and a diaphragm located at one end portion thereof, a housing having an opening at one end portion thereof, and a pressure transmission member operating to transmit a pressure applied thereto to the sensing section. The first and second tubular members are integrally connected to each other at their the opening sections. A fixing portion between the first and the second tubular members is located inside the housing, an outer periphery of the second tubular member is fixed to an inner periphery of the opening section of the housing.

Abstract: A temperature detecting device includes a heat receiving plate, a displacement transmitting part, a deforming part, a deformation generating part and a displacement detecting part. The heat receiving plate is restrained at its rim portion to generate a displacement of a central portion in its thickness direction with respect to the rim portion in accordance with the temperature of an atmospheric gas. The displacement transmitting part is displaced in accordance with the displacement of the central portion of the heat receiving plate. The deforming part is deformed by the displacement transmitting part. The deformation generating part maintains a distance between the rim portion of the heat receiving plate and the deforming part. The displacement detecting part detects a deformation of the deforming part and outputs an electric signal.

Abstract: A pressure detection device includes a sensing part that is provided at one end portion of the housing to output an electrical signal responsive to an applied pressure, a circuit part that is provided at an other end portion of the housing to process the signal from the sensing part, and a flexible printed board provided in the housing between the sensing part and the circuit part. Furthermore, the flexible printed board has a first end portion electrically connected to the sensing part at a first connecting part, and a second end portion electrically connected to the circuit part at a second connecting part. In the pressure detection device, the flexible printed board is shaped between the first and second end portions to relieve a stress applied to the connecting parts.

Abstract: A collision detection device for a vehicle includes a first direction signal outputting unit which detects an intensity of heat ray radiated from a detection object which is near or contacts the vehicle to outputs a first direction signal, a second direction signal outputting unit which detects ultrasound wave sent by a sending member and reflected by the detection object to output a second direction signal, an impact signal outputting unit which detects an impact on the vehicle to output an impact signal, and a control unit. The control unit determines an occurrence of a collision between the vehicle and a human, in the case where it is determined that a difference between the first direction signal and the second direction signal is within a first predetermined range and the impact signal is outputted.

Abstract: A pressure sensor includes a sensor chip and a circuit chip. The sensor chip, which is configured to generate an electrical signal representative of a pressure being sensed, has a surface including a sensing area and a plurality of electrical contact pads disposed on the surface. The circuit chip includes a circuit configured to process the electrical signal and has a surface on which a plurality of electrical contact pads of the circuit chip are disposed. The circuit chip is joined to the sensor chip so that the electrical contact pads of the circuit chip are respectively electrically connected to those of the sensor chip, all the electrical contact pads of the circuit chip and the sensor chip are hermetically sealed and isolated from the fluid, and the surfaces of the circuit chip and the sensor chip face each other with the electrical contact pads of the same interposed therebetween.

Abstract: A pressure sensor includes a connector case having a recess, in which a sensor chip is contained and an oil is filled. The recess filled with the oil is sealed by a metal diaphragm. The sensor chip for outputting signals and the circuit chip having a processing circuit for processing the signals from the sensor chip, are stacked. That is, the circuit chip is provided between a bottom wall surface of the recess and the sensor chip. The processing circuit is covered by at least a part of the sensor chip, and the processing circuit of the circuit chip is arranged at a place where the processing circuit can avoid contact with the oil. Because the processing circuit of the circuit chip is not exposed to the oil, the processing circuit can be effectively restricted from being charged due to a polarization of the oil.

Abstract: A sensor device for use in an automobile as an airflow sensor is composed of a silicon substrate in which a cavity is formed and a base plate bonded to the silicon substrate. An upper end of the cavity is closed with a thin membrane including a sensor element such as a temperature sensor element, while a lower end of the cavity is closed with the base plate. An air passage having a small cross-section is formed through the base plate, so that the cavity communicates with the outside air through the air passage. The thin membrane is prevented from being damaged by collision with foreign particles included in the airflow because the air in the cavity functions as a damper. The air passage may be made in the silicon substrate in parallel to its surface without using the base plate.

Abstract: One end of a rod-like pressure-conveying member is disposed in a sensing unit, and the other end extends into and through an insertion hole of an engine. A combustion pressure, to which the other end of the rod-like member is exposed, is conveyed to the sensing unit through the pressure-conveying member for the detection of the combustion pressure. The pressure-conveying member resonates at a knocking frequency fn of the engine and the knocking frequency fn is detected based on the resonance of the pressure-conveying member.

Abstract: A pressure sensor chip includes a diaphragm and pads. A flexible printed circuit board (FPC) includes a resin sheet having a through-hole and wiring patterns that are formed within the resin sheet and sealed. The resin sheet is press-fitted to the pressure sensor chip such that the diaphragm is bared at the through-hole. The wiring patterns are connected to the pads, and junctions between the wiring patterns and the pads are sealed with the resin sheet.

Abstract: A pressure sensor mainly includes a sensor chip, a circuit chip, and a substrate. The sensor chip is configured to generate an electrical signal representative of a pressure being sensed and includes a sensing area and a plurality of contact pads. The circuit chip includes a circuit configured to process the electrical signal and a plurality of contact pads. The substrate includes a resin sheet having an opening and a plurality of conductors within the resin sheet. The substrate is joined to both the sensor chip and circuit chip so that the sensing area of the sensor chip is to be exposed to the pressure being sensed through the opening of the resin sheet, the contact pads of the sensor chip and circuit chip are electrically connected to the conductors of the substrate, and all the contact pads and conductors are hermetically embedded in the resin sheet of the substrate.

Abstract: A gas sensor includes a semiconductor substrate and a sensing membrane. The sensing membrane is located at the bottom of a recess, which is formed by etching the substrate, and includes a heater, heater extension electrodes, a gas sensitive film, and gas-sensitive-film extension electrodes. A first end of each heater extension electrode is in contact with the heater, and a second end of each heater extension electrode extends outward from the sensing membrane. A first end of each gas-sensitive-film extension electrode is in contact with the gas sensitive film, and a second end of each gas-sensitive-film extension electrode extends outward from the sensing membrane. All of the heater, the heater extension electrodes, and the gas-sensitive-film extension electrodes are made of polycrystalline silicon.

Abstract: A motor-assisted turbocharger is composed of a turbine driven by energy of exhaust gas, a compressor rotated by the turbine and a rotary electric machine for assisting rotation of the compressor. The turbine, the compressor and the rotary electric machine are connected to each other by a common rotating shaft. A polygon nut having magnetic member facing fixed magnetic sensor is connected to an axial end of the rotating shaft. A magnetic field formed between the magnetic member and the magnetic sensor changes according to rotation of the rotating shaft. A rotational speed and a rotational position (or angle) of the compressor are detected based on the changes in the magnetic field. Operation of the turbocharger is electronically controlled based on the detected rotational speed and the rotational position.

Abstract: A pressure detection device includes a sensing part that is provided at one end portion of the housing to output an electrical signal responsive to an applied pressure, a circuit part that is provided at an other end portion of the housing to process the signal from the sensing part, and a flexible printed board provided in the housing between the sensing part and the circuit part. Furthermore, the flexible printed board has a first end portion electrically connected to the sensing part at a first connecting part, and a second end portion electrically connected to the circuit part at a second connecting part. In the pressure detection device, the flexible printed board is shaped between the first and second end portions to relive a stress applied to the connecting parts.

Abstract: Magnetoresistive devices are formed on the insulating surface of a substrate made of silicon. The devices are connected in series through an insulating film using a wiring layer formed on the surface of the substrate. An insulating film for passivation is formed to cover the devices and the wiring layer. A magnetic shield layer of Ni—Fe alloy is formed on the passivation insulating film through an organic film for relieving thermal stress to cover one of the devices. After removal of the sensor chip containing the magnetoresistive devices and other components from the wafer, the chip is bonded to a lead frame through an Ag paste layer by heat treatment. Preferably, the magnetic shield layer is made of a Ni—Fe alloy having a Ni content of 69% or less.

Abstract: A pressure sensor includes a connector case having a recess, in which a sensor chip is contained and an oil is filled. The recess filled with the oil is sealed by a metal diaphragm. The sensor chip for outputting signals and the circuit chip having a processing circuit for processing the signals from the sensor chip, are stacked. That is, the circuit chip is provided between a bottom wall surface of the recess and the sensor chip. The processing circuit is covered by at least a part of the sensor chip, and the processing circuit of the circuit chip is arranged at a place where the processing circuit can avoid contact with the oil. Because the processing circuit of the circuit chip is not exposed to the oil, the processing circuit can be effectively restricted from being charged due to a polarization of the oil.