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:
Aug. 15, 2000
Filed:
Mar. 05, 1998
Applicant:
Inventors:
Assignee:
NGK Insulators, Ltd., , JP;
Attorney:
Primary Examiner:
Assistant Examiner:
Int. Cl.
CPC ...
H01L / ;
U.S. Cl.
CPC ...
338 / ; 3382 / ; 338 25 ;
Abstract
A composite PTC material made of cristobalite as a matrix and a conductive filler, having a room temperature resistivity of 10.sup.-1 .OMEGA.cm or less. The conductive filler is at least one substance selected from the group consisting of single metals, metal silicides, metal carbides and metal borides; has a room temperature resistivity of 10.sup.-3 .OMEGA.cm or less when per se made into a sintered material; has particle diameters of 2-50 .mu.m; and is contained in a proportion of 20-35% by volume of the composite PTC material. The composite PTC material has a relative density of 90% or more after firing.