Method for producing thin-film magnetic recording medium
US4948626A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Feb 2, 1989 |
| Grant date | Aug 14, 1990 |
| Priority date | — |
| Expiry date | Feb 2, 2009 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG11B5/85
- WIPO fieldAudio-visual technology
- WIPO sectorElectrical engineering
Abstract
A method for producing a thin-film magnetic recording medium having an improved corrosion resistance and which permits production of the medium at a high speed. A magnetic material vapor flow from an evaporation source and a gas or ion flow are applied to a nonmagnetic base in an evaporation chamber and the two flows reacted with each other to form the thin-film magnetic layer on the nonmagnetic base. During this process, the expression P.sub.1 /P.sub.0 .ltoreq.0.1 is maintained, wherein P.sub.0 represents the degree of vacuum in the evaporation chamber, under a first condition where only the gas or ion flow is applied after the pressure in the chamber has been reduced to a predetermined degree of vacuum, and P.sub.1 represents the degree of vacuum in the chamber under a second condition where the magnetic material vapor flow is applied to the nonmagnetic base simultaneously with the gas or ion flow. The rate of formation of the thin-film magnetic layer is 200 .ANG./sec or more on the average.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.