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US4842708A Expired / Lapsed US ⏱️ 0.0 years remaining

Perpendicular magnetic recording medium, method for producing the same, and sputtering device

Assignee: Teijin Ltd
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Filing: 1987-03-06
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Granted: 1989-06-27
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Expires: 2007-03-06
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Abstract

Abstract A magnetic recording medium conventionally utilizes the in-plane magnetization mode, but recently the perpendicular magnetization mode utilizing the perpendicular anisotropy of an hcp cobalt alloy layer, in which the C axis is oriented perpendicular to the layer surface, has been proposed. The known perpendicular magnetic recording medium is produced by means of RF sputtering and comprises a Permalloy layer, as layer of a low coercive-force material, between the nonmagnetic base and the hcp cobalt alloy layer. The perpendicular anisotropy attained by the present invention in very excellent and is superior to that of a perpendicular recording medium having no Permalloy layer because a Co-Ta alloy is used as the layer of a low coercive-force material.

Inventors

  • 👤 Sadao Kadokura
  • 👤 Kazuhiko Honjo
  • 👤 Takashi Tomie
  • 👤 Masahiko Naoe

Bibliographic Details

Application Number —
Jurisdiction US
Data Source google_patents
Last Synchronized 2026-11-08 10:24
CPC Classifications
G; G11; G11B; G11B5/00; G11B5/62; G11B5/64; G11B5/66; G11B5/672; G11B5/84; G11B5/851; Y; Y10; Y10S; Y10S428/00; Y10S428/922; Y10S428/9265; Y10S428/928; Y10T; Y10T428/00; Y10T428/12; Y10T428/12465; Y10T428/12493; Y10T428/12771; Y10T428/12861; Y10T428/12931

Claims Analysis

Total Claims: 6
Claim 1
Independent Claim 173 words
A sputtering device comprising: a vacuum vessel; at least one pair of rectangular targets arranged in the vacuum vessel so that their long sides are opposed; at least one means for generating a magnetic field along the perimeter of each of said rectangular targets in a direction perpendicular to the targets, each of said magnetic-field generating means having an end portion thereof positioned close to one of said targets, each end portion constituted by a tip made of high permeability soft magnetic materials, said tip having an outside front and being shaped into a point at the outside front end thereof; and a base-conveying means for conveying a nonmagnetic base arranged adjacent to the long sides of said at least one pair of said rectangular targets so that the nonmagnetic base faces a space between said at least one pair of the targets in a direction perpendicular to the long side of said targets, and so that layers having the same composition of said targets are deposited on said nonmagnetic base by sputtering.
Claim 2
Dependent Claim 173 words
A sputtering device comprising: a vacuum vessel; at least one pair of rectangular targets arranged in the vacuum vessel so that their long sides are opposed; at least one means for generating a magnetic field along the perimeter of each of said rectangular targets in a direction perpendicular to the targets, each of said magnetic-field generating means having an end portion thereof positioned close to one of said targets, each end portion constituted by a tip made of high permeability soft magnetic materials, said tip having an outside front and being shaped into a point at the outside front end thereof; and a base-conveying means for conveying a nonmagnetic base arranged adjacent to the long sides of said at least one pair of said rectangular targets so that the nonmagnetic base faces a space between said at least one pair of the targets in a direction perpendicular to the long side of said targets, and so that layers having the same composition of said targets are deposited on said nonmagnetic base by sputtering.
Claim 3
Dependent Claim 180 words
A sputtering device comprising: a vacuum vessel; at least one pair of rectangular targets arranged in the vacuum vessel so that their long sides are opposed; at least one means for generating a magnetic field outside and along the perimeter of each of said at least one pair of rectangular targets in a direction perpendicular to the targets, each of said magnetic-field generating means comprising first means for guiding a magnetic flux around each of said targets with a configuration such that each of said targets is surrounded thereby, and second means for producing a magnetic field and connected to said first means via a magnetic path formed therebetween; and base-conveying means for conveying a nonmagnetic base arranged adjacent to the long sides of said at least one pair of said rectangular targets so that the nonmagnetic base faces a space between said at least one pair of the targets in a direction perpendicular to the long sides of said targets, and so that layers having the same composition of said targets are deposited on said nonmagnetic base by sputtering.
Claim 4
Dependent Claim 180 words
A sputtering device comprising: a vacuum vessel; at least one pair of rectangular targets arranged in the vacuum vessel so that their long sides are opposed; at least one means for generating a magnetic field outside and along the perimeter of each of said at least one pair of rectangular targets in a direction perpendicular to the targets, each of said magnetic-field generating means comprising first means for guiding a magnetic flux around each of said targets with a configuration such that each of said targets is surrounded thereby, and second means for producing a magnetic field and connected to said first means via a magnetic path formed therebetween; and base-conveying means for conveying a nonmagnetic base arranged adjacent to the long sides of said at least one pair of said rectangular targets so that the nonmagnetic base faces a space between said at least one pair of the targets in a direction perpendicular to the long sides of said targets, and so that layers having the same composition of said targets are deposited on said nonmagnetic base by sputtering.
Claim 5
Dependent Claim 15 words
A sputtering device according to claim 2, wherein said second means is a magnetizing coil.
Claim 6
Dependent Claim 15 words
A sputtering device according to claim 2, wherein said second means is a permanent magnet.

USPTO Annuity & Maintenance Windows

Annuity Stage Window Opens Payment Deadline Surcharge Period Until Estimated Fee Status
3.5 Years (Year 4) 1992-06-26 1992-12-26 1993-06-27 $2000.00 Window Closed / Lapsed
7.5 Years (Year 8) 1996-06-26 1996-12-26 1997-06-27 $3760.00 Window Closed / Lapsed
11.5 Years (Year 12) 2000-06-26 2000-12-26 2001-06-27 $7700.00 Window Closed / Lapsed

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