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. 24, 1989
Filed:
Dec. 29, 1988
NGK Insulators, Ltd., Nagoya, JP;
Abstract
A method of forming, on a surface of a Mn-Zn ferrite single crystal, a recessed portion which has a predetermined cross sectional profile and at least one straight ridge each of which defines a boundary in the profile. An etching mask is formed on the surface of the ferrite single crystal, so as to provide the recessed portion by etching such that each straight edge of the profile lies in a (100) or (110) plane of the ferrite single crystal which is perpendicular to the surface on which the etching mask is formed. The ferrite single crystal with the etching mask in exposed to an aqueous solution which substantially consists of water and the balance consisting principally of phosphoric acid, whereby the surface of the ferrite single crystal is chemically etched, so as to produce the recessed portion such that an inclined surface is formed so as to extend parallel to the straight ridge, and such that the straight ridge defines an edge of the inclined surface.