THERMAL AIR FLOWMETER

• Main Authors: OGATA KIMITOSHI, ISHIZUKA NORIO, TOKUYASU NOBORU, TASHIRO SHINOBU
• Format: Patent
• Language: English; Japanese
• Published: 18.05.2015
• Subjects: MEASURING; MEASURING VOLUME, VOLUME FLOW, MASS FLOW OR LIQUIDLEVEL; METERING BY VOLUME; PHYSICS; TESTING

PROBLEM TO BE SOLVED: To provide a thermal air flowmeter having high measuring accuracy.SOLUTION: A thermal air flowmeter comprises: a sub-passage which takes in a part of fluid to be measured; a sensor chip 4 which has a hollow part and a diaphragm made of a thin film part which is formed so as to cover the hollow part, and is arranged in the sub-passage; a circuit part which converts a fluid flow rate detected by the sensor chip 4 into an electric signal; a connector part which is electrically connected to the circuit part and outputs the signal to the outside; and a housing which supports the sensor chip 4 and the circuit part. The flowmeter includes a ventilation plate on which the sensor chip 4 is mounted and the plurality of air passages communicating with the hollow part are formed, a surface of the sensor chip and the plate are molded by resin such that the diaphragm of the sensor chip and a part of the plate are exposed, the hollow part and the outside of the mold package are communicated by the plurality of air passages, and the plurality of air passages join at an outlet opening part which connects the outside of the mold package. 【課題】計測精度の高い熱式空気流量計を提供する。【解決手段】被計測流体の一部を取り込む副通路と、空洞部と空洞部を覆うように形成された薄膜部からなるダイアフラムとを有し副通路に配置されたセンサチップ４と、センサチップ４により検出した流体流量を電気信号に変換する回路部と、回路部と電気的に接続され外部に信号を出力するコネクタ部と、センサチップ４及び回路部を支持する筐体と、を備える熱式空気流量計において、センサチップ４が実装され、空洞部を連通する空気通路が複数形成された換気用のプレートを備え、センサチップ及びプレートの表面は、センサチップのダイアフラム及びプレートの一部が露出するように樹脂でモールドされ、空洞部と前記モールドパッケージの外部とが複数の空気通路で連通され、複数の空気通路は、モールドパッケージの外部を連結する出口開口部で合流する熱式空気流量計。【選択図】図１