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:
Sep. 22, 1998
Filed:
May. 13, 1996
Matsushita Electric Industrial Co., Ltd., Osaka, JP;
Abstract
By performing a debinder process before or at the time of firing, and by enhancing a programming rate in the temperature range of 650.degree..about.950.degree. C., the size of particles shows less distribution. Also, when the temperature comprising the particle growth range of 1025.degree..about.1200.degree. C. is maintained for many hours, a zinc oxide varistor having relatively large and uniformly formed particles can be provided. When a zinc oxide varistor compound is fired, a solid solution of zinc oxide spinel is fired at the programming rate of 175.degree. to 500.degree. C./hr in the temperature range comprising the primary phase of from 650.degree. to 950.degree. C., and at the programming rate of 30.degree. to 500.degree. C./hr in the range of from 1250.degree. to 1300.degree. C. Accordingly, a zinc oxide varistor having comparatively large and uniformed formed particles can be obtained. Sintered products obtained in this way show less distribution in operating voltage.