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US 8,300,340 B2Granted
Magnetic recording medium
AssigneeKabushiki Kaisha Toshiba
InventorsMasatoshi Sakurai, Ryosuke Yamamoto, Naoko Kihara, Akiko Yuzawa, Yoshiyuki Kamata
Life of this patent
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Abstract
According to one embodiment, a servo area of a magnetic recording medium includes magnetic dots arrayed at a period L0. The magnetic dots include a plurality of magnetic dot regions divided in the cross track direction. A width Wm in the down track direction of the mth magnetic dot region from the innermost circumference and a number Nm of dot rows in the down track direction of the mth region meet a relationship represented by L0{Nm√3/2−0.3}≦Wm≦L0{Nm√3/2+0.3} (1).
Claims5
A disk-like magnetic recording medium comprising:
- a servo area along an arc corresponding to a locus when a reproduction head moves on the magnetic recording medium in a cross track direction, the servo area comprising magnetic dots aligned at a pitch (L0),
- wherein the magnetic dots comprise at least m magnetic dot regions in the cross track direction, where m is natural number equal to 2 or more, the magnetic dots formed on a surface of a magnetic recording layer by a method comprising:
- forming a first stamper comprising a pectin pattern corresponding to at least m magnetic dot regions in a cross track direction, where m is natural number equal to 2 or more;
- transferring the projecting pattern of the first stamper onto a resist layer on a substrate by:
- imprinting,
- forming a guide by curing the resist,
- causing phase separation by applying a self-organizing material into the guide,
- forming a self-organizing dot pattern corresponding to dots aligned at a pitch (L0), and
- forming a second stamper based on the self-organizing dot pattern;
- preparing a magnetic recording medium comprising a substrate and a magnetic recording layer on the substrate;
- forming a pattern transfer resist material coating layer on the magnetic recording layer;
- adhering a pattern surface of the second stamper by using the coating layer;
- curing the coating layer;
- removing the second stamper;
- forming a resist material layer on the magnetic recording layer, the resist material layer being cured after the transferring;
- and
- dry-etching using the cured resist material layer as a mask, thereby forming the magnetic dots on a surface of the magnetic recording layer, and
- wherein a width (Wm) in a down track direction of an m-th magnetic dot region from an innermost circumference of the magnetic recording medium, among the at least m magnetic dot regions, and a number of dot rows (Nm) in the down track direction of the m-th region satisfy the expression (1),
- and the magnetic dots satisfying the expression (1) are in a preamble portion,
- L0{Nm√3/2−0.23}≦Wm≦L0{Nm√3/2+0.24} (1)
- wherein L0 ranges from 17 to 45 nm, and Nm is not more than 6.
18 more elements
A magnetic recording/reproduction apparatus comprising:
- a reproduction head attached to a pivotal actuator arm and configured to move on a magnetic recording medium in a cross track direction;
- and
- a magnetic recording medium comprising:
- a servo area along an arc corresponding to a locus when the reproduction head moves on the magnetic recording medium in a cross track direction,
- wherein the servo area comprises magnetic dots aligned at a pitch (L0),
- the magnetic dots comprise at least m magnetic dot regions in the cross track direction, where m is natural number equal to 2 or more,
- the magnetic dots formed on a surface of a magnetic recording layer by a method comprising:
- forming a first stamper comprising a projecting pattern corresponding to at least m magnetic dot regions in a cross track direction, where m is natural number equal to 2 or more;
- transferring the projecting pattern of the first stamper onto a resist layer on a substrate by:
- imprinting,
- forming a guide by curing the resist,
- causing phase separation by applying a self-organizing material into the guide,
- forming a self-organizing dot pattern corresponding to magnetic dots aligned at a pitch (L0), and
- forming a second stamper based on the self-organizing dot pattern;
- preparing a magnetic recording medium comprising a substrate and a magnetic recording layer on the substrate;
- forming a pattern transfer resist material coating layer on the magnetic recording layer;
- adhering a pattern surface of the second stamper by using the coating layer;
- curing the coating layer;
- removing the second stamper;
- forming a resist material layer on the magnetic recording layer, the resist material layer being cured after the transferring;
- and
- dry-etching using the cured resist material layer as a mask, thereby forming the magnetic dots on a surface of the magnetic recording layer, and
- a width (Wm) in a down track direction of an m-th magnetic dot region from an innermost circumference of the magnetic recording medium, among the at least m magnetic dot regions, and a number of dot rows (Nm) in the down track direction of the m-th region satisfy the expression (1),
- L0{Nm√3/2−0.23}≦Wm≦L0{Nm√3/2+0.24} (1)
- wherein L0 ranges from 17 to 45 nm, and Nm is not more than 6.
22 more elements
A method of manufacturing a magnetic recording medium comprising a servo area along an arc corresponding to a locus the method comprising:
- forming a first stamper comprising a projecting pattern corresponding to at least m magnetic dot regions in a cross track direction, where m is natural number equal to 2 or more;
- transferring the projecting pattern of the first stamper onto a resist layer on a substrate by:
- imprinting,
- forming a guide by curing the resist,
- causing phase separation by applying a self-organizing material into the guide,
- forming a self-organizing dot pattern corresponding to magnetic dots aligned at a pitch (L0), and
- forming a second stamper based on the self-organizing dot pattern;
- preparing a magnetic recording medium comprising a substrate and a magnetic recording layer on the substrate;
- forming a pattern transfer resist material coating layer on the magnetic recording layer;
- adhering a pattern surface of the second stamper by using the coating layer;
- curing the coating layer;
- removing the second stamper;
- forming a resist material layer on the magnetic recording layer, the resist material layer being cured after the transferring;
- and
- dry-etching using the cured resist material layer as a mask, thereby forming the magnetic dots on a surface of the magnetic recording layer,
- wherein a width (Wm) in a down track direction of an m-th magnetic dot region from an innermost circumference of the magnetic recording medium, among the at least m magnetic dot regions, and a number Nm of dot rows in the down track direction of the m-th region satisfying the expression (1),
- and the magnetic dots satisfying the expression (1) are in a preamble portion:
- L0{Nm√3/2−0.23}≦Wm≦L0{Nm√3/2+0.24} (1).
15 more elements
Dependencies are inferred from the claim text.