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:
Apr. 12, 2005
Filed:
Sep. 20, 2002
Junichi Horie, Hitachinaka, JP;
Yasuo Onose, Tokai-mura, JP;
Norio Ichikawa, Mito, JP;
Seiji Kuryu, Hitachinaka, JP;
Satoshi Shimada, Hitachi, JP;
Akihiko Saito, Hadano, JP;
Keiji Hanzawa, Mito, JP;
Masahiro Matsumoto, Hitachi, JP;
Hiroshi Moriya, Chiyoda-machi, JP;
Akio Yasukawa, Kashiwa, JP;
Atsushi Miyazaki, Mito, JP;
Junichi Horie, Hitachinaka, JP;
Yasuo Onose, Tokai-mura, JP;
Norio Ichikawa, Mito, JP;
Seiji Kuryu, Hitachinaka, JP;
Satoshi Shimada, Hitachi, JP;
Akihiko Saito, Hadano, JP;
Keiji Hanzawa, Mito, JP;
Masahiro Matsumoto, Hitachi, JP;
Hiroshi Moriya, Chiyoda-machi, JP;
Akio Yasukawa, Kashiwa, JP;
Atsushi Miyazaki, Mito, JP;
Hitachi, Ltd., Tokyo, JP;
Hitachi Car Engineering Co., Ltd., Hitachinaka, JP;
Abstract
By sealing a diaphragm with less processes and lower cost and reducing deformation due to remaining stress, a stable and highly reliable pressure sensor construction is proposed. The pressure sensor is low in measurement error and small in floating capacitance and leakage current and good in characteristic. As a means to attain the above object, a polycrystalline silicon diaphragm is sealed with a silicon oxide film deposited through a LPCVD method and then completely covered. The diaphragm is placed on a surface of a semiconductor substrate with a nearly constant gap of 0.15 to 1.3 μm, and has difference-in-grade constructions of a deformation reducing means due to remaining stress.