Ceramic heater, method of producing the same, and glow plug using this ceramic heater

摘要

A ceramic heater in which a damage in a joining portion between a heating portion and a lead portion is suppressed and the reliability is excellent is provided. The ceramic heater (1) comprises: a rod-shaped support (2) extending in an axial direction, and comprising an insulative ceramic; and a resistor member (3) including a heating portion (31) embedded in a tip end part of said support, and a pair of lead portions (33) extending from said heating portion toward a rear end side of said support. Said heating portion and said lead portions comprise the same conductive ceramic. Said ceramic heater has, in a part of said heating portion (31), a flat part in which a width w of said heating portion in a section of said heating portion is larger than a thickness h of said heating portion perpendicular to the width. Said flat part has a projection which is formed by projecting a part of said heating portion.