Patent ID: 6744016
Filing Date: 2004-06-01
Classification: C04B,F23Q,H05B

Abstract:
A ceramic heater comprising:a silicon nitride ceramic substrate having a surface layer portion and an internal layer portion, said silicon nitride ceramic substrate containing a rare-earth component serving as a sintering-aid component and said rare-earth component being present in the form of a composite oxide with silicon; a resistance heating member embedded in said silicon nitride ceramic substrate, and an Al-thickened layer having a thickness of 50 &mgr;m to 1000 &mgr;m and formed in said surface layer portion of said silicon nitride ceramic substrate, wherein said Al-thickened layer has an average Al concentration of 0.1% to 5% by weight and higher than that of said internal layer portion of said silicon nitride ceramic substrate, and said composite oxide is contained in the form of R2SiO5, where R is said rare-earth component.