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:
Oct. 02, 2007
Filed:
Feb. 21, 2006
Shinichi Nakagawa, Kounan Aichi, JP;
Yoshihiro Nakano, Komaki Aichi, JP;
Masahito Kida, Nisikasugai Aichi, JP;
Takio Kojima, Ichinomiya Aichi, JP;
Shinichi Nakagawa, Kounan Aichi, JP;
Yoshihiro Nakano, Komaki Aichi, JP;
Masahito Kida, Nisikasugai Aichi, JP;
Takio Kojima, Ichinomiya Aichi, JP;
NGK Spark Plug Co., Ltd., Aichi-ken, JP;
Abstract
The present invention provides a gas sensor having excellent humidity resistance even if used in a high temperature and high humidity atmosphere. According to the present invention, a gas sensor is comprised of: a silicon substrate; a metal-oxide semiconductor portion comprised mainly of SnOand formed on the substrate; and a catalytic portion comprised of Pd and dispersed on a surface of the metal-oxide semiconductor portion, wherein the metal-oxide semiconductor portion and the catalytic portion constitute a gas sensing portion. Furthermore, an insulating portion comprised mainly of SiOis formed dispersedly on a surface of the gas sensing portion. Further, the catalytic portion and the insulating portion are formed on the surface of the metal-oxide semiconductor portion so that the surface additive rate, which is expressed by Si/(Pd+Si) representing the ratio in the number of atoms of Si to Pd, of the gas sensing portion having the insulating portion may be 65% or more to 97% or less, and so that the surface additive rate, which is expressed by Si/(Sn+Si) representing the ratio in the number of atoms of Si to Sn, of the gas sensing portion may be 75% or more to 97% or less.