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:
Dec. 07, 1999
Filed:
Nov. 08, 1994
Satoshi Tanaka, Kokubu, JP;
Jun Fukuda, Kokubu, JP;
Kyocera Corporation, Kyoto, JP;
Abstract
A silicon nitride ceramic heater comprising a base body of silicon nitride ceramics, and a heating element embedded in the body, the ceramic heater being characterized in that the element further comprises, as a main ingredient, at least one of carbides, nitrides or silicides selected from the metal group consisting of W, Mo, Re, Cr, Ti, Ta, Ni and Co, and not more than 75 vol % of the BN content in combination with the main ingredient. This composition can reduce the difference in thermal expansion coefficients between the heating element and the silicon nitride ceramics and can thus prevent the heating element from being cracked by thermal stress. Consequently, the silicon nitride ceramic heater is superior in durability and can maintain high performance for a long time.