The patent badge is an abbreviated version of the USPTO patent document. The patent badge does contain a link to the full patent document.
The patent badge is an abbreviated version of the USPTO patent document. The patent badge covers the following: Patent number, Date patent was issued, Date patent was filed, Title of the patent, Applicant, Inventor, Assignee, Attorney firm, Primary examiner, Assistant examiner, CPCs, and Abstract. The patent badge does contain a link to the full patent document (in Adobe Acrobat format, aka pdf). To download or print any patent click here.
Patent No.:
Date of Patent:
Oct. 19, 2004
Filed:
Sep. 26, 2001
Masatoshi Ueki, Aichi, JP;
Takio Kojima, Aichi, JP;
Yoshinori Tsujimura, Aichi, JP;
Kouichi Ikawa, Gifu, JP;
Yoshihiko Kohmura, Aichi, JP;
Takafumi Oshima, Aichi, JP;
NGK Spark Plug Co., Ltd., Aichi, JP;
Abstract
A mass flow sensor includes a semiconductor substrate , an insulating thin film , heaters and , temperature measurement resistors and , and a protective layer . The heaters and are formed on the surface of the insulating thin film , and are provided adjacently such that the heater is provided upstream the heater and the heater is provided downstream the heater . A cavity is formed below the heaters and , and the heaters are thermally insulated from the remaining portion of the semiconductor substrate. The temperature measurement resistors and are formed on the top surface of the insulating thin film , and are provided at opposite sides of the heaters and , such that the resistors are aligned with respect to the flow passage of a fluid. In the mass flow sensor and the mass flowmeter including the sensor, the flow rate and flow direction of a fluid can be detected by means of merely the heaters and , which are active elements. Therefore, the sensor and the flowmeter exhibits high-speed response with respect to change in the flow rate of the fluid.