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:
Nov. 07, 2000
Filed:
Jan. 29, 1999
Masahiro Konishi, Kariya, JP;
Shindo Watanabe, Nagoya, JP;
NGK Spark Plug Co., Ltd., Nagoya, JP;
Abstract
Ceramic raw powder containing conductive ceramic powder is mixed with a prescribed quantity of a molding assistant containing carbon component. This mixture is molded into a prescribed shape of a resistive heating element to thereby produce a heating element mold. A composite mold is prepared by embedding the heating element mold into molds of a ceramic substrate. The composite mold is sintered at a sintering temperature of 1700.degree. C. or higher. During a process of rising temperature to the sintering temperature, the composite mold is kept in an oxygen containing atmosphere having an oxygen partial pressure of 2.times.10.sup.-4 to 1.0 Torr for 7 minutes or longer at a temperature of 1200.degree. C. or higher.