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:
Oct. 22, 2002
Filed:
Mar. 01, 2001
Minebea Co., Ltd., Kitasaku-gun, JP;
Abstract
The present invention provides a Mn—Zn ferrite having an electrical resistivity exceeding 1 &OHgr;m order and a low core loss in a high frequency region exceeding 1 MHz. A basic component composition of the Mn—Zn ferrite includes 44.0 to 49.8 mol % of Fe O , 6.0 to 15.0 mol % of ZnO (15.0 mol % is excluded), 0.1 to 3.0 mol % of CoO, 0.02 to 1.20 mol % of Mn O , and the remainder of MnO. The Mn—Zn ferrite achieves desired purposes by controlling Fe O content to a range less than 50 mol % that is the stoichiometric composition, adding a proper amount of CoO, restraining amount of Mn O formation to 1.20 mol % or less, and further setting their average grain sizes to less than 10 &mgr;m.