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. 25, 1979
Filed:
Jul. 10, 1978
Applicant:
Inventors:
Tatsuro Kikuchi, Kyoto, JP;
Kenichi Fujimura, Katano, JP;
Hyogo Hirohata, Neyagawa, JP;
Tetsuo Hino, Hirakata, JP;
Assignee:
Attorney:
Primary Examiner:
Int. Cl.
CPC ...
C25F / ; C25F / ;
U.S. Cl.
CPC ...
20412965 ; 20412975 ; 20412995 ;
Abstract
An etchant comprising an electrolytic liquid which comprises sulfuric acid as a main component and water in such amount that the weight ratio of sulfuric acid to water is between 9:1 and 2:1. The ferrite surface having been electrolytically etched by using this etchant is smooth. Thus, this etchant makes it possible to etch a ferrite to a large depth, and thereby easily shape a ferrite by electrolytic etching, e.g. to define the track width of a magnetic head.