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:
May. 09, 1995
Filed:
Jul. 14, 1993
Eigo Hirotsuji, Konan, JP;
Naoya Fukuda, Aichi, JP;
NGK Insulators, Ltd., , JP;
Abstract
An etching method for etching a sendust film formed on a substrate is disclosed. In this method, a mixture of acid solutions of nitric acid and hydrochloric acid is used as an etching liquid. The etching is desirably effected while the sendust film is directly or indirectly held in electrical connection with a ferrite member, with an area of a portion of the ferrite member which contacts the etching liquid being twice to twelve times a total area of etched portions of the sendust film. Also disclosed is a method for pattern-etching a sendust film, and a chromium base film formed between the sendust film and a substrate, which includes the steps of: (a) etching the sendust film to form a predetermined sendust pattern; and (b) etching the chromium base film to form a chromium pattern which conforms to the predetermined sendust pattern, such that the chromium base film is directly or indirectly held in electrical connection with a chromium bulk.