Hitachi Automotive Systems, Ltd.

Hitachi, Ltd.

Hitachi Astemo Ltd.

Hitachi Car Engineering Co., Ltd.

Other

Yasuo Onose

Masahiro Matsumoto

Hiroshi Nakano

Satoshi Shimada

Junichi Horie

Keiji Hanzawa

Seiji Kuryu

Norio Ichikawa

Atsuo Watanabe

Noriyuki Sakuma

Norio Ishitsuka

Atsushi Miyazaki

Akihiko Saito

Hiroaki Hoshika

Ryosuke Doi

Yoshimitsu Yanagawa

Satoshi Asano

Shinya Satou

Takeshi Morino

Shinobu Tashiro

Takayuki Yogo

Hiroshi Moriya

Akio Yasukawa

Naohiro Momma

Yuki Okamoto

Hiroki Nakatsuchi

Ryotaro Shimada

Akihiko Saitou

Kazuhiro Ohta

A thermal sensor device capable of maintaining measurement accuracy for a long period by suppressing plastic deformation due to thermal expansion of the heat generating resistor and reducing resistance change of the heat generating resistor, includes: a substrate having an opening; and a diaphragm having a structure in which a lower film, a heat generating resistor, and an upper film are stacked so as to bridge the opening, in which a film thickness of the lower film is larger than a film thickness of the upper film, an average thermal expansion coefficient of the lower film is larger than an average thermal expansion coefficient of the upper film, the lower film includes a plurality of films having different thermal expansion coefficients, and a film having a largest thermal expansion coefficient among the plurality of films is formed below a thickness center of the lower film.

Thermal sensor device

A flow-rate sensor is provided with a lead frame, a semiconductor chip that is disposed on one surface of the lead frame, and in which a diaphragm including a void portion on the lead frame side is formed, a flow rate detecting unit that is formed on the one surface including the diaphragm of the semiconductor chip, and resin that includes a flow passage opening portion exposing at least a portion of the flow rate detecting unit formed on the diaphragm, and covers the lead frame and the semiconductor chip. A lower side resin portion of the resin covering another surface side of the lead frame, on an opposite side to the one surface side thereof, has a thinned portion that is thinner than a periphery thereof in a region facing a peripheral edge portion of the diaphragm.

Flow-rate sensor

The purpose of the present invention is to provide a highly accurate and highly reliable physical quantity sensor wherein an error due to stress applied to a sensor element of the physical quantity sensor is reduced. This physical quantity sensor device is provided with: a hollow section formed in a Si substrate; an insulating film covering the hollow section; and a heating section formed in the insulating film. The sensor device is also provided with a detection element that detects the temperature of the insulating film above the hollow section, the detection element is provided with a first silicon element and a second silicon element, and the first silicon element and the second silicon element are doped with different impurities, respectively.

Sensor device

Provided are a semiconductor device and a thermal type fluid flow rate sensor which suppress strain occurring in an aluminum film and suppresses disconnection due to repeated metal fatigue of the aluminum film. The semiconductor device and the thermal type fluid flow rate sensor of the present invention are configured so that the heights of a silicon film and an aluminum film satisfy D&#x3e;Dbetween a flow rate sensor part (immediately above a diaphragm end part) D and a circuit part (LSI part) D

Semiconductor element and flow rate measurement device using same

An object of the present invention is to provide a gas sensor device capable of detecting a temporal change with high accuracy and maintaining measurement accuracy over a long period under a temperature environment susceptible to a complicated and wide range of change. The gas sensor device includes: heat insulating filmsandformed on a substrate; a first heaterprovided on the heat insulating filmsandand configured to measure physical quantity of gas; and a reference resistorformed in a resistive layer same as the first heater and formed on the heat insulating filmsand. The gas sensor device further includes a second heaterthat simultaneously heats the first heaterand the reference resistor

Gas sensor device

A sensor device includes a detection resistor having a resistance value changing according to a physical quantity and a reference resistor compared with the detection resistor, the reference resistor is configured by electrically connecting a first resistance circuit and a second resistance circuit. The first resistance circuit includes a first and a second resistive element having positive and negative resistance temperature coefficients, respectively, which are electrically connected. The second resistance circuit includes a third and a fourth resistive elements having a positive and a negative resistance temperature coefficient, respectively, which are electrically connected. The first resistance circuit is configured to generate a first deviation to either the positive or negative side with respect to a temperature change, and the second resistance circuit is configured to generate a second deviation to the side opposite to the positive or negative side where the first deviation is generated.

To provide a gas sensor device having improved measurement accuracy. This gas sensor device is provided with: a sensor element that detects the concentration of a gas by means of heat dissipation from a heat generating body; and a cover with which the sensor element is covered. The cover has a plurality of ventilation sections, which are disposed by being separated with each other in the direction perpendicular to the flowing direction of the gas, and the sensor element is disposed between the ventilation sections.

The purpose of the present invention is to provide a gas sensor device with which highly accurate measurement performance can be achieved even if there are changes in the environmental temperature. The present invention is provided with: a detection heater () formed in a thin film part; a temperature compensation heater () formed so as to surround the detection heater; a detection heater heating control circuit for controlling the heating temperature of the detection heater (); and a temperature compensation heater heating control circuit for controlling the heating temperature of the temperature compensation heater to a heating temperature lower than the heating temperature of the detection heater. The detection heater heating control circuit and the temperature compensation heater heating control circuit adjust the respective heating currents in response to an increase in the temperature of a substrate, so as to reduce the temperature difference between the heating temperature of the detection heater () and the heating temperature of the temperature compensation heater ().

Gas sensor device, and heating current control method for gas sensor device

Degradation of reliability of a thermal fluid flow sensor, caused by generation of a crack in an insulating film is prevented in the thermal fluid flow sensor including a detection section and a circuit section formed on the same substrate when stress adjustment is performed by forming a deep concave portion in an interlayer insulating film in the detection section and forming the insulating film having a tensile stress thereon. As a means thereof, stair-like step is provided in a side wall of a concave portion, formed in the interlayer insulating film on a diaphragm. Accordingly, each depth of a first concave portion and a second concave portion, which form the concave portion, is reduced, and coatability of the insulating film for the stress adjustment, which covers a side wall and a bottom face of the concave portion, is improved.

Thermal fluid flow sensor

The purpose of the present invention is to provide a thermal flow-rate sensor that is capable of self-diagnosis. Provided is a thermal flow-rate sensor provided with a semiconductor element that detects a flow rate and that is equipped with electrode pads for electrical conduction with the outside, wherein at least two of the electrode pads are provided, and other electrode pads proximate to the electrode pads are arranged and have an electric potential beyond the scope of output to be used at the time of flow rate detection.

Thermal air flow-rate sensor

A gas sensor includes a first heating element and a second heating element that is formed around the periphery of the first heating element and has a wider forming area than the first heating element. A gas amount is measured by heating the first heating element to a predetermined temperature, in which the second heating element is heated when the gas sensor is activated, and the first heating element is heated to the predetermined temperature after a heat value of the first heating element is restricted for a predetermined period of time.

Gas sensor

In order to provide a thermal mass flowmeter which makes higher accuracy of gas flowrate measurement possible while reliability in the thermal mass flowmeter is ensured (while deterioration or breakage caused by droplet adhesion is prevented), the thermal mass flowmeter according to the present invention has a heating element for generating heat by conduction, a temperature detection bridge circuit for detecting a temperature of the heating element, and a sensor element driving circuit portion connected to the heating element and the temperature detection bridge circuit and executing conduction control to the heating element, in which the sensor element driving circuit portion has an output mechanism and an output impedance adjustment mechanism and the output impedance adjustment mechanism is disposed between the output mechanism and the heating element and its output impedance is higher than an electric resistance value of the heating element and less than 1 M&#x3a9;.

Thermal mass flowmeter

A thermal air flow sensor that produces less measurement error is provided. The thermal air flow sensor includes: a semiconductor substrate; a heating resistor, resistance temperature detectors, and an electrical insulator that includes a silicon oxide film, wherein the heating resistor, the resistance temperature detectors, and the electrical insulator are formed on the semiconductor substrate; and a diaphragm portion formed by removing a portion of the semiconductor substrate. The heating resistor and the resistance temperature detectors are formed on the diaphragm portion. The thermal air flow sensor further includes a silicon nitride film formed as the electrical insulator above the heating resistor and the resistance temperature detectors. The silicon nitride film has steps conforming to the patterns of the heating resistor and the resistance temperature detectors. The silicon nitride film has a multilayer structure.

Thermal air flow sensor

A thermal air flow sensor that offers high flow rate measurement accuracy is provided. The thermal air flow sensor includes a measuring element. The measuring element includes: a semiconductor substrate; a heating resistor and a temperature measuring resistor both formed as a result of thin films being stacked over the semiconductor substrate; an electronic insulator including a silicon oxide film; and a diaphragm portion formed after part of the semiconductor substrate is removed. The heating resistor and the temperature measuring resistor are formed over the diaphragm portion. In the thermal air flow sensor, a ratio of an area occupied by the thin films to an area of the measuring element ranges between 40% and 60%.

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Hitachinaka, Japan

Yasuo Onose