Process of lift off of material
US4481071A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Dec 29, 1983 |
| Grant date | Nov 6, 1984 |
| Priority date | — |
| Expiry date | Dec 29, 2003 |
Classification
- Technology area (CPC Y)Emerging Cross-Sectional Technologies
- CPC primaryY10T29/49044
- WIPO fieldAudio-visual technology
- WIPO sectorElectrical engineering
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.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.