Patent ID: 7712349
Filing Date: 2010-05-11
Classification: G01N

Abstract:
1. A gas sensor comprising: a gas detection element; a ceramic wiring substrate on which the gas detection element is mounted; and a protective cap which is directly attached to the ceramic wiring substrate in such a manner as to cover the gas detection element, the protective cap is made of metal and defines, when attached to the ceramic wiring substrate, a gas-measuring space in cooperation with the ceramic wiring substrate, and has a gas intake for introducing gas to be measured into the gas measuring space from the outside thereof; wherein the gas detection element is mounted in a cavity of the ceramic wiring substrate; wherein the gas detection element includes a diaphragm structure section which is formed of a silicon substrate, and the diaphragm structure section includes a gas detection portion; wherein the ceramic wiring substrate has a multilayer structure in which a plurality of ceramic dielectric layers are laminated; a recess is formed on a portion of a side surface of the ceramic wiring substrate which corresponds to a side surface of a ceramic dielectric layer other than an uppermost ceramic dielectric layer which forms a top surface of the ceramic wiring substrate; wherein the protective cap is held on the ceramic wiring substrate in a nonadhering condition; and wherein the protective cap has a perpendicularly projecting portion extending along the side surface of the ceramic wiring substrate; and an engagement projection to be fitted into the recess is formed on the perpendicularly projecting portion.