Method of producing a metallic thin film magnetic disk

Patent 4426265 Issued on January 17, 1984. Estimated Expiration Date:

February 26, 2002. Estimated Expiration Date is calculated based on simple USPTO term provisions. It does not account for terminal disclaimers, term adjustments, failure to pay maintenance fees, or other factors which might affect the term of a patent.

Abstract Claims Description Full Text

Patent References

3850690

Epitaxial process of forming ferrite, Fe₃ O₄ and γFe₂ O₃ thin films on special materials
Patent #: 3996095
Issued on: 12/07/1976
Inventor: Ahn , et al.

Corrosion resistant magnetic recording media
Patent #: 4245008
Issued on: 01/13/1981
Inventor: Michaelsen , et al.

Method of producing magnetic recording medium Patent #: 4260466
Issued on: 04/07/1981
Inventor: Shirahata , et al.

Inventors

Application

No. 06/352736 filed on 02/26/1982

US Classes:

204/192.2, Ferromagnetic204/192.15, Specified deposition material or use428/900MAGNETIC FEATURE

Examiners

Primary: Pianalto, Bernard

Attorney, Agent or Firm

Madden, Jr.; Walter J.

International Classes

H01F 41/18 (20060101)
H01F 41/14 (20060101)
H01F 41/20 (20060101)
G11B 5/84 (20060101)
G11B 5/851 (20060101)

Foreign Application Priority Data

1981-04-11 DE

Abstract

For a metallic thin film magnetic disk, a chromium undercoat and a magnetic layer, in particular of an FeCoCr alloy, are obliquely sputtered by means of a sputtering system onto a substrate at an angle of incidence of about 60°. The operating pressure of the argon gas atmosphere is between 5 and 15 μbar and the thickness (tCr) of the undercoat, which also influences the coercive field strength, is between about 50 and 180 nm. By means of a sector shutter of suitable shape, the thickness distribution between the inner diameter ID and the outer diameter OD of the storage area of the magnetic disk can be influenced in the desired manner.