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. 31, 1982
Filed:
Oct. 01, 1980
David A Payne, Champaign, IL (US);
Sang M Park, Penn Yan, NY (US);
University of Illinois Foundation, Urbana, IL (US);
Abstract
A semiconducting internal boundary layer ceramic composition having a fine grain structure suitable for use in thin-layer multilayer capacitors is made in one step by firing a mixture comprising a major amount of finely divided strontium titanate, a minor amount of a compound containing either strontium or titanium, or an element functionally equivalent thereto, a minor amount of a semiconductor forming ingredient (dopant), the identity of which depends on whether the mixture is rich in strontium or in titanium, and a minor amount of a counterdopant selected from cuprous oxide or silver oxide. When the mixture is rich in titanium, the chemical doping agent used to produce semiconductivity is an oxide of a trivalent metal selected from bismuth, boron, iron, antimony, lanthanum and the rare earth and transition metals. When the mixture is rich in strontium, the dopant is an oxide of a pentavalent or hexavalent metal selected from tungsten (+6), niobium (+5), tantalum (+5), and molybdenum (+6).