The patent badge is an abbreviated version of the USPTO patent document. The patent badge does contain a link to the full patent document.
The patent badge is an abbreviated version of the USPTO patent document. The patent badge covers the following: Patent number, Date patent was issued, Date patent was filed, Title of the patent, Applicant, Inventor, Assignee, Attorney firm, Primary examiner, Assistant examiner, CPCs, and Abstract. The patent badge does contain a link to the full patent document (in Adobe Acrobat format, aka pdf). To download or print any patent click here.
Patent No.:
Date of Patent:
Apr. 04, 2006
Filed:
Nov. 27, 2002
Shindo Watanabe, Aichi, JP;
Masahiro Konishi, Aichi, JP;
Katsuhisa Yabuta, Aichi, JP;
NGK Spark Plug Co., Ltd., Aichi, JP;
Abstract
A green ceramic heater including a green heating resistor formed of an electrically conductive ceramic (e.g., silicide or carbide of a metal element such as W, Ta, or Nb) and an insulative ceramic (e.g., silicon nitride) and power supply leads (e.g., made of W), a first end of each power supply lead being connected to a corresponding end of the green heating resistor, the green heating resistor and the power supply leads buried in a green substrate formed of a material (e.g., silicon nitride) is fired, and subsequently, the resultant ceramic heater is heat-treated at 900 to 1,600° C., to thereby enhance flexural strength of the ceramic heater. The heat treatment is preferably carried out prior to forming a glass layer on an outer circumferential surface of the ceramic heater. When the heat treatment is performed after the fired ceramic heater has been polished so as to expose a second end of each power supply lead from a surface of the substrate, the heat treatment is preferably carried out in an inert atmosphere.