Claims
- 1. A method of producing a magnetic disk, comprising a surface processing step of forming fine depressions and projections in a surface of a non-magnetic substrate or a surface of at least one of a magnetic film and a protective film which are formed on said substrate, wherein said surface processing step is carried out in such a manner that when a surface shape of said substrate or a surface shape of said one film is evaluated and represented in terms of a load ratio BR5 of a three-dimensional load curve and a symmetric property Rsk of a cross-sectional shape, said load ratio of said surface shape is 0.5% to 10%, and said symmetric property Rsk of said surface shape is 0.5 to 2.0.
- 2. A method according to claim 1, in which said non-magnetic substrate comprises an aluminum alloy disk plated with Ni--P, wherein said surface processing step of forming the fine depressions and projections in said Ni--P plated surface is carried out in such a manner that when the surface shape of said substrate is evaluated and represented in terms of a load ratio BR5 of a three-dimensional load curve and a symmetric property Rsk of a cross-sectional shape, said load ratio of said surface shape is 0.5% to 10%, and said symmetric property Rsk of said surface shape is 0.5 to 2.0.
- 3. A method according to claim 1, comprising the step of processing said non-magnetic substrate into a mirror surface; the fine depressions and projections being formed on at least one of said magnetic film and said protective film in said surface processing step; wherein said surface processing step is carried out in such a manner that when the surface shape of said one film is evaluated and represented in terms of a load ratio BR5 of a three-dimensional load curve and a symmetric property Rsk of a cross-sectional shape, said load ratio of said surface shape is 0.5% to 10%, and said symmetric property Rsk of said surface shape is 0.5 to 2.0.
- 4. A method according to any one of claims 1 to 3, in which said surface processing step for processing the surface in such a manner that said load ratio of 0.5% to 10% and said symmetric property Rsk of 0.5 to 2.0 are satisfied comprises the step of etching by lithography.
- 5. A method according to any one of claims 1 to 3, in which said surface processing step for processing the surface in such a manner that said load ratio of 0.5% to 10% and said symmetric property Rsk of 0.5 to 2.0 are satisfied comprises the step of applying an energy beam.
- 6. A method according to any one of claims 1 to 3, in which said surface processing step for processing the surface in such a manner that said load ratio of 0.5% to 10% and said symmetric property Rsk of 0.5 to 2.0 are satisfied comprises the step of forming fine grooves in a circumferential direction of the disk or in a random direction, using a diamond tool having a distal end whose radius of curvature is fine.
Priority Claims (1)
Number |
Date |
Country |
Kind |
3-275193 |
Oct 1991 |
JPX |
|
Parent Case Info
This is a divisional of application Ser. No. 07/964,897, filed Oct. 22, 1992, now U.S. Pat. No. 5,388,020.
US Referenced Citations (3)
Number |
Name |
Date |
Kind |
4833001 |
Kijima et al. |
May 1989 |
|
5166006 |
Lal et al. |
Nov 1992 |
|
5353182 |
Nakamura et al. |
Oct 1994 |
|
Divisions (1)
|
Number |
Date |
Country |
Parent |
964897 |
Oct 1992 |
|