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:
Jun. 03, 1997
Filed:
Jun. 13, 1996
Masaru Fukuda, Kitakyushu, JP;
Tadashi Ogasawara, Akita, JP;
Toshio Marui, Akita, JP;
Dai Matsuoka, Akita, JP;
TDK Corporation, Tokyo, JP;
Abstract
A voltage-dependent nonlinear resistor or varistor ceramic composition consists essentially of (1) an oxide of the formula: {Sr.sub.(1-x-y) Ba.sub.x Ca.sub.y }.sub.z TiO.sub.3 wherein 0.3<x.ltoreq.0.9, 0.1.ltoreq.y.ltoreq.0.5, x+y.ltoreq.1, and 0.84<z<1.16, (2) 0.001 to 5.000 mol % of at least one oxide of niobium, tantalum, tungsten, manganese or R wherein R is yttrium or lanthanide, (3) 0.001 to 5.000 mol % of SiO.sub.2, and (4) 0.001 to 5.000 mol % of MgO. When the varistor voltage is controlled by changing a re-oxidizing temperature without changing the composition, a satisfactory nonlinear index .alpha. is available over a wide range of varistor voltage. The dependency of varistor voltage on heat treating temperature is reduced.