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US 12,537,025 B2Granted
Method for manufacturing magnetic disk, magnetic disk, and magnetic disk precursor
AssigneesHoya Corporation, Hoya Glass Disk Vietnam II Ltd.
InventorsShinji Eda, Kenichi Nishimori
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Abstract
A magnetic disk used in a hard disk drive device includes a substrate; a magnetic recording layer; and a heat insulating layer provided between the substrate and the magnetic recording layer. Even though a substrate has low heat resistance, as a result of providing the heat insulating layer, the substrate can be used as a substrate for a magnetic disk that can withstand heat treatment (high-temperature annealing).
Claims6
A method for manufacturing a magnetic disk for perpendicular magnetic recording, the method comprising:
- producing a magnetic disk precursor having
- an annular-shaped substrate,
- a magnetic film that overlays the substate and is a magnetic recording layer,
- a soft magnetic layer that overlays the substate, and
- a heat insulating layer provided between the substrate and the magnetic film;
- and
- performing heat treatment on an entirety of a main surface of the magnetic disk precursor by spirally irradiating the entirety of the main surface of the magnetic disk precursor with a laser beam, and
- the heat treatment being performed for increasing a magnetic anisotropy constant Ku of the magnetic film.
5 more elements
Dependencies are inferred from the claim text.