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. 15, 2011
Filed:
Sep. 28, 2007
Gaofeng Wang, San Jose, CA (US);
Chih-chang Chen, Cupertino, CA (US);
Yahong Yao, Milpitas, CA (US);
Liji Huang, San Jose, CA (US);
Gaofeng Wang, San Jose, CA (US);
Chih-Chang Chen, Cupertino, CA (US);
Yahong Yao, Milpitas, CA (US);
Liji Huang, San Jose, CA (US);
Siargo Ltd., Santa Clara, CA (US);
Abstract
An integrated mass flow sensor is manufactured by a process of carrying out a micro-machining process on an N or P-type silicon substrate with orientation <100>. This mass flow sensor comprises an upstream thin-film heater, an downstream thin-film heater, and a pair of thin-film heat sensing elements, and a thermally isolated membrane for supporting the heaters and the sensors out of contact with the substrate base. This mass flow sensor is operated with three sets of circuits, a first circuit for measuring a flow rate in a first range of flow rates, a second circuit for measuring a flow rate in a second range of flow rates, and a third circuit in a differential configuration for measuring a flow rate in said first range of flow rates or said second range of flow rates, to significantly increase range of flow rate measurements and provide an optional for concentration measurement, while maintains a high degree of measurement accuracy.