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:
Mar. 13, 2012
Filed:
Aug. 10, 2009
Chih-chang Chen, Cupertino, CA (US);
Gaofeng Wang, San Jose, CA (US);
Liji Huang, San Jose, CA (US);
Yahong Yao, Sunnyvale, CA (US);
Chih-Chang Chen, Cupertino, CA (US);
Gaofeng Wang, San Jose, CA (US);
Liji Huang, San Jose, CA (US);
Yahong Yao, Sunnyvale, CA (US);
Other;
Abstract
A micromachined thermal mass flow sensor comprises a high mechanical strength polyimide film as a supporting layer of suspending membrane. The polyimide film provides superior thermal insulating properties to reduce the power consumption of device. Due to the tendency of humidity absorption, the polyimide suspending membrane is double side passivated on both top and bottom surfaces to sustain its long term stability from rush and humid working environment. A thin layer of silicon dioxide deposited by plasma enhanced chemical vapor deposition is overlaid between the silicon nitride and polyimide film to enhance the adhesion property of passivation layers to polyimide surface. With such embodiments, a sturdy and robust micromachined thermal mass flow sensor with high measurement accuracy could be formed.