Title:
SEMICONDUCTOR FLOW METER AND MICROPUMP USING THIS METER
Document Type and Number:
Japanese Patent JPH0412230
Kind Code:
A
Abstract:
PURPOSE:To measure a very small flow rate with high accuracy by providing a check valve whose passage resistance is large in a low flow rate area, and whose passage resistance becomes small in a high flow rate area, and measuring a flow rate of a fluid, based on a detection output of a strain gage. CONSTITUTION:On the lower face of a silicon substrate 40, a diaphragm 42 for generating a stress corresponding to differential pressure of both faces of the substrate 40 is formed, and in the vicinity of the center of the diaphragm 42, a minute hole 44 tapered from the upstream side to the downstream side is formed. There diaphragm 42 and minute hole 44 can be formed with high accuracy by a unit of micron order by performing a crystal anisotropic etching treatment by using an alkali etching liquid to the substrate 40. Also, on the substrate 40, a check valve 60 is provided on the downstream side of the minute hole 44, and the valve 60 is formed so that the passage resistance becomes large in a low rate area, and the passage resistance becomes small in a high flow rate area. In such a state, by measuring a flow rate of a fluid, based on a detection output of a strain gauge 46, a very small flow rate can be measured with this accuracy.
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Inventors:
ESASHI MASAKI
KAWABATA MASARU
SUGIYAMA SUSUMU
KAWABATA MASARU
SUGIYAMA SUSUMU
Application Number:
JP11427990A
Publication Date:
January 16, 1992
Filing Date:
April 30, 1990
Export Citation:
Assignee:
TOYOTA CENTRAL RES & DEV
JAPAN RES DEV CORP
JAPAN RES DEV CORP
International Classes:
G01F1/20; F04B53/00; (IPC1-7): G01F1/20
Attorney, Agent or Firm:
Fuse Yukio (1 person outside)
Next Patent: JPH0412231