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:
Nov. 06, 1984
Filed:
Dec. 29, 1983
Nathaniel C Anderson, Pine Island, MN (US);
Robert B Chesnut, Rochester, MN (US);
Larry E Daby, Rochester, MN (US);
International Business Machines Corporation, Armonk, NY (US);
Abstract
Process for lift-off fabrication of sputtered dielectric or nonmagnetic gap materials and thin-film heads for either a single-element thin-film head or side-by-side elements on a thin-film head. The lift-off process utilizes a copper coating that is removed by a twenty percent solution of ammonium persulfate with a pH in the range of seven to nine to assure complete removal of gap material from the back closure of the thin-film head without damage to the underlying permalloy. The process can also be utilized to obtain a multiple layer deposits on a single thin-film had by repeating the steps of the process. The process provides for a clean hole, no dielectric on the surface nor any attacking on the magnetic material.