Gas sensor
US7276745B2 · kind B2 · utility
Assignee
Inventors
Key dates
| Filing date | Feb 21, 2006 |
| Grant date | Oct 2, 2007 |
| Priority date | — |
| Expiry date | Feb 21, 2026 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG01N27/125
- WIPO fieldMeasurement
- WIPO sectorInstruments
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 SnO2 and 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 SiO2 is 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.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.