Thermal flow meter

Patent metadata

Field	Value
Publication number	US-10012522-B2
Application number	US-201715476007-A
Country	US
Kind code	B2
Filing date	Mar 31, 2017
Priority date	Dec 7, 2011
Publication date	Jul 3, 2018
Grant date	Jul 3, 2018

Abstract

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.

First claim

The invention claimed is:

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

2. The thermal-type flowmeter according to claim 1 , wherein the chip package is in a shape with a portion thereof, where the temperature detecting element is mounted, being protruded.

3. The thermal-type flowmeter according to claim 2 , wherein a direction of the protrusion of the portion of the chip package is an upstream direction of a flow of the fluid under measurement.

4. The thermal-type flowmeter according to claim 2 , wherein a direction of the protrusion of the portion of the chip package is a direction perpendicular to the flow of
the fluid under measurement.

5. The thermal-type flowmeter according to claim 2 , wherein the chip package has a connection terminal for electrical connection with an outside of the chip package, and is in a shape with the portion thereof being protruded in a direction perpendicular to a direction of the connection terminal.

6. The thermal-type flowmeter according to claim 2 , wherein the chip package has the connection terminal for electrical connection with the outside of the chip package, and is in a shape with the portion thereof being protruded in a direction horizontal to the direction of the connection terminal.

7. The thermal-type flowmeter according to claim 1 , further comprising a sub-flow path that takes in a part of a fluid under measurement passing through a main flow path, wherein the chip package is provided such that a portion on which the sensor element is mounted is disposed in the sub-flow path and a portion on which the temperature detecting element is mounted is disposed in the main flow path.

8. The thermal-type flowmeter according to claim 1 , wherein:
the metal lead frame has a mounting portion on which the drive circuit is mounted and a protruding portion that protrudes from the mounting portion, and
the temperature detecting element is mounted on the protruding portion.

9. The thermal-type flowmeter according to claim 1 , wherein the chip package has a capacitor mounted on the lead frame, the capacitor being encapsulated with the resin.

Assignees

• Hitachi Automotive Systems Ltd

Inventors

• Tokuyasu Noboru
• Tashiro Shinobu
• Hanzawa Keiji
• Morino Takeshi
• Doi Ryosuke

Classifications

• G01F1/684

  Structural arrangements; Mounting of elements, e.g. in relation to fluid flow · CPC title

• G01F5/00

  Measuring a proportion of the volume flow · CPC title

• G01F1/692 Primary

  Thin-film arrangements · CPC title

• F02D41/187

  using a hot wire flow sensor · CPC title

• G01F15/04

  of gases to be measured · CPC title