Hitachi Automotive Systems, Ltd.

Hitachi Astemo Ltd.

Ryosuke Doi

Keiji Hanzawa

Shinobu Tashiro

Noboru Tokuyasu

Takeshi Morino

Akira Uenodan

Hiroshi Nakano

Masahiro Matsumoto

Yasuo Onose

Noriyuki Sakuma

Satoshi Asano

Kazunori Suzuki

Hiroshi Kikuchi

Hideki Mukuno

Satoshi Ikeo

Toshifumi Sagawa

A thermal airflow sensor includes a sensor element, a bonding wire, a resin, and a protective film. The sensor element has a thin-wall portion. The thin-wall portion has a heating resistor. The bonding wire is electrically connected to the sensor element. The resin covers the bonding wire. The protective film is formed on a surface of the sensor element so that the heating resistor is exposed. The protective film has at least a slit between the resin and the thin-wall portion.

Thermal airflow sensor

The present invention has been made to improve measurement accuracy of a thermal flow meter. In the thermal flow meter according to the invention, a circuit package () that measures a flow rate is molded in a first resin molding process. In a second resin molding process, a housing () having an inlet trench (), a bypass passage trench on frontside (), an outlet trench (), and the like are formed through resin molding, and an outer circumferential surface of the circuit package () produced in the first resin molding process is enveloped by a resin in the second resin molding process to fix the circuit package () to the housing ().

Thermal flow meter including a cover mounted on a housing and where a bypass passage is formed by the cover and a bypass passage trench

In order to provide a flow measuring device high in thermal responsiveness, the flow measuring device includes a temperature detecting elementfor temperature detection, and a conductive metal lead framethat supports and fixes the temperature detecting element. Of the metal lead frame, a part of the metal lead frame mounted with the temperature detecting element has a portion which is thinner than the thickness of the other metal lead frame or narrower than the width of the other metal lead frame.

Thermal airflow measuring device

A thermal flowmeter circuit package having a side of a measurement surfaceof the circuit package and a flow pathat a side of the backside of measurement surfaceof a rear surface of the measurement surface, and an inflow-side end surface of the circuit package for dividing the measurement target gashas different shapes at the side of the measurement surface and at the side of the backside of measurement surface. The inflow-side end surface of the circuit package for dividing the measurement target gasis formed with a reference linedividing the measurement target gas, and an end surfaceat the side of the measurement surface with respect to the reference line and an end surfaceat the side of the backside of measurement surface with respect to the reference line are formed to be asymmetrical.

Thermal flow meter with an asymmetrical inflow-side of circuit package

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 thermal-type flowmeter includes a chip package. The chip package is formed through encapsulation with a resin of a sensor element, a drive circuit, a metal lead frame adapted to have mounted thereon the sensor element and the drive circuit, and a temperature detecting element. The chip package has an exposed structure in which a surface of the sensor element having the diaphragm is exposed. The temperature detecting element is mounted on the lead frame via an electrically conductive member.

Thermal flow meter

Provided is a thermal flow meter to improve the measurement accuracy of a temperature detector. The thermal flow meter includes a bypass passage through which a measurement target gas flowing through a main passage flows, and a circuit package which includes a measurement circuit for measuring a flow rate of the measurement target gas flowing through the bypass passage and a temperature detecting portion for detecting a temperature of the measurement target gas. The circuit package includes a circuit package body which is molded by a resin to internally envelope the measurement circuit and a protrusion molded by the resin. The temperature detecting portion is provided in the leading end portion of the protrusion, and at least the leading end portion of the protrusion protrudes to the outside from a housing.

Thermal flow meter with a case having an external terminal for outputting an electric signal

A thermal airflow sensor includes a semiconductor device, a protective film a bonding wire, and a resin. The resin covers over a part of the semiconductor device so that the bonding wire is covered with the resin and the region including a thin-wall portion is exposed. The protective film is not covered with the resin and has an outer peripheral edge located outside the thin-wall portion.

Thermal flow meter including a cover mounted on a housing and where a bypass passage is formed by the cover and bypass passage trench

A thermal flow sensor with improved measurement accuracy is provided. The thermal flow sensor includes: an air flow rate detection element with a diaphragm having a thin-film portion in a semiconductor substrate; at least one heat generating resistor on the diaphragm; at least one temperature measuring resistor that detects temperature on each of an upstream side and a downstream side of the heat generating resistor; and a correction circuit portion that processes an output signal of the air flow rate detection element on the basis of temperature difference information of at least the two temperature measuring resistors on the upstream side and the downstream side, wherein a waveform of the output signal processed by the correction circuit portion is a waveform obtained by cutting a part of a mountain part or a valley part constituting a peak value by outputting of an arbitrary predetermined value when the peak value of the waveform exceeds the arbitrary predetermined value.

Growing community of inventors

Hitachinaka, Japan

Ryosuke Doi