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:
Jul. 07, 2009
Filed:
Feb. 15, 2006
Hiroshi Nakano, Hitachi, JP;
Masahiro Matsumoto, Hitachi, JP;
Masamichi Yamada, Hitachinaka, JP;
Keiichi Nakada, Hitachinaka, JP;
Izumi Watanabe, Hitachinaka, JP;
Hiroshi Nakano, Hitachi, JP;
Masahiro Matsumoto, Hitachi, JP;
Masamichi Yamada, Hitachinaka, JP;
Keiichi Nakada, Hitachinaka, JP;
Izumi Watanabe, Hitachinaka, JP;
Hitachi, Ltd., Tokyo, JP;
Abstract
A highly accurate physical quantity sensor which can ensure reliability in strength and reduce resistance changes caused by stresses. Assuming, with respect to stress σ imposed on a substrate in a predetermined direction (e.g., direction in which maximum stress is imposed), a parallel direction to be a horizontal direction and a perpendicular direction to be a vertical direction, each of resistors of the sensor has a horizontal resistance component Rl and a vertical resistance component Rt. When a ratio of a piezoresistance coefficient πl of the horizontal resistance component Rl, which is provided when the stress imposed on the substrate is applied to the horizontal resistance component Rl, to a piezoresistance coefficient πt of the vertical resistance component Rt, which is provided when the stress is applied to the vertical resistance component Rt, is πl:πt=−n:1 (n:integer), a resistance value ratio of the vertical resistance component Rt to the horizontal resistance component Rl is set substantially equal to the ratio of the piezoresistance coefficient πl to πt.