FLOW SENSOR

• Main Author: ITO KEIYA
• Format: Patent
• Language: English; Japanese
• Published: 05.10.2017
• Subjects: MEASURING; MEASURING VOLUME, VOLUME FLOW, MASS FLOW OR LIQUIDLEVEL; METERING BY VOLUME; PHYSICS; TESTING

PROBLEM TO BE SOLVED: To provide a flow sensor with which it is possible to improve environmental resistance without increasing manufacturing processes while improving heat radiation performance.SOLUTION: The flow sensor comprises: a sub-passage formation member for forming a sub-passage 15 for guiding a fluid flowing in a main passage; a flow rate detection chip 11 in which a sensing unit for detecting the flow rate of the sub-passage 15 is formed; a circuit chip 12 electrically connected to the flow rate detection chip 11; a lead frame having a surface 13a on which the circuit chip 12 is mounted and a reverse side 13b, with the flow rate detection chip 11 connected to the mounting surface; a resin molding 14 for sealing the circuit chip 12 while leaving the sensing unit exposed; a first temperature measurement resistor for detecting the atmospheric temperature of the flow rate detection chip 11; and a second temperature measurement resistor for detecting the atmospheric temperature of the circuit chip 12. The resin molding 14 has its bottom constituted by a portion of the reverse side of the lead frame and has a hole 28 that opens to the outer surface of the resin molding. The lead frame is constructed to be exposed via the hole 28 to a fluid flowing in the sub-passage 15.SELECTED DRAWING: Figure 6 【課題】放熱性を向上しつつ、製造工程を増やさずに耐環境性を向上できる流量センサを提供すること。【解決手段】流量センサは、主通路を流れる流体を導く副通路１５を形成する副通路形成部材と、副通路１５の流量を検出するセンシング部が形成された流量検出チップ１１と、流量検出チップ１１と電気的に接続された回路チップ１２と、回路チップ１２が搭載された表面１３ａ及び裏面１３ｂを有し、搭載面に流量検出チップ１１が接続されたリードフレームと、センシング部を露出させつつ、回路チップ１２を封止する樹脂成形体１４と、流量検出チップ１１の雰囲気温度を検出する第１測温抵抗と、回路チップ１２の雰囲気温度を検出する第２測温抵抗を備える。樹脂成形体１４は、リードフレームの裏面の一部が底をなし、樹脂成形体の外面に開口する孔部２８を有する。リードフレームは、孔部２８を介して、副通路１５を流れる流体に晒されるようになっている。【選択図】図６