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:
May. 17, 2005
Filed:
Aug. 20, 1999
Shinya Satou, Hitachi, JP;
Satoshi Shimada, Hitachi, JP;
Atsuo Watanabe, Hitachiota, JP;
Yasuo Onose, Toukai, JP;
Seiji Kuryu, Hitachinaka, JP;
Atsushi Miyazaki, Mito, JP;
Junichi Horie, Hitachinaka, JP;
Naohiro Momma, Hitachi, JP;
Shinya Satou, Hitachi, JP;
Satoshi Shimada, Hitachi, JP;
Atsuo Watanabe, Hitachiota, JP;
Yasuo Onose, Toukai, JP;
Seiji Kuryu, Hitachinaka, JP;
Atsushi Miyazaki, Mito, JP;
Junichi Horie, Hitachinaka, JP;
Naohiro Momma, Hitachi, JP;
Hitachi, Ltd., Tokyo, JP;
Hitachi Car Engineering Co., Ltd., Hitachinaka, JP;
Abstract
The object of the present invention is to propose an etch channel sealing structure characterized by excellent impermeability to moisture and resistance to temporal change of the diaphragm in the pressure sensor produced according to the sacrificial layer etching technique, and to provide a pressure sensor characterized by excellent productivity and durability. After a very small gap is formed by the sacrificial layer etching technique, silicon oxide film is deposited by the CVD technique or the like, thereby sealing the etch channel. Further, impermeable thin film of polysilicon or the like is formed to cover the oxide film. This allows an etch channel sealing structure to be simplified in the pressure sensor produced according to the sacrificial layer etching technique, and prevents entry of moisture into the cavity, thereby improving moisture resistance. Moreover, sealing material with small film stress reduces temporal deformation of the diaphragm.