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:
Jun. 12, 2007
Filed:
Mar. 24, 2005
Masamichi Yamada, Hitachinaka, JP;
Junichi Horie, Hitachinaka, JP;
Izumi Watanabe, Hitachinaka, JP;
Keiichi Nakada, Hitachinaka, JP;
Masamichi Yamada, Hitachinaka, JP;
Junichi Horie, Hitachinaka, JP;
Izumi Watanabe, Hitachinaka, JP;
Keiichi Nakada, Hitachinaka, JP;
Hitachi, Ltd., Tokyo, JP;
Hitachi Car Engineering Co., Ltd., Hitachinaka-shi, JP;
Abstract
A gas flowmeter capable of reducing a secular change comprises a silicon semiconductor substrate formed with a cavity and a heat element formed above the cavity of the semiconductor substrate by way of an insulating film. The heat element is a silicon (Si) semiconductor thin film impurity-doped at high concentration. Stoichiometrically stable silicon nitride (SiN) thin films as barrier layers which less permeate and less absorb hydrogen in the heat generating temperature range of the heat element are formed above and below the silicon (Si) semiconductor thin film.