Patent ID: 6676817
Filing Date: 2004-01-13
Classification: G01N,Y10T

Abstract:
A gas sensor including an electrochemical cell for detecting a gas concentration, comprising a co-fired laminate of:an insulating ceramic substrate including a heater and heater leads embedded in the insulating ceramic substrate, said insulating ceramic substrate mainly comprising alumina; an oxygen-ion conductive solid electrolyte layer having a thickness of from 10-70 &mgr;m comprising solid electrolyte ceramic including 10% to 80% by weight of insulating ceramic grains and having first and second metallic electrodes disposed thereon, said first and second metallic electrodes are disposed on opposite sides of the solid electrolyte layer, and said first metallic electrode is disposed on the side of the solid electrolyte layer closest to the insulating ceramic substrate; and a reinforcing ceramic layer having a relative density of 60% to 99.5% provided on the second metallic electrode, wherein the insulating ceramic substrate including the embedded heater and heater leads, the oxygen-ion conductive solid electrolyte layer including the first and second metallic electrodes and the reinforcing ceramic layer are co-fired at a temperature of 1400-1600Â° C. to form a laminate in which the oxygen-ion conductive solid electrolyte layer is integrally formed on the insulating ceramic substrate, said first metallic electrode is an embedded self-generating oxygen-reference electrode, and said second metallic electrode is a gas-measuring electrode.