Apparatus for cleaning magnetic disks and methods for manufacturing magnetic disks

1. An apparatus, comprising:

a mechanism for supporting and rotating a magnetic disk; and

at least one pair of mechanisms for wiping or tape-cleaning both sides of the magnetic disk, each of the pair of mechanisms including:

a feed reel and a take-up reel for a wiping cloth or a cleaning tape;

a plurality of guide rollers between the feed reel and the take-up reel for guiding the wiping cloth or the cleaning tape onto a surface of the magnetic disk;

a mechanism for controlling tension in the wiping cloth or the cleaning tape between the guide rollers to a predetermined level;

a pressure mechanism for pressing a pad mounted with a strain gage sensor against the wiping cloth or the cleaning tape guided onto the surface of the magnetic disk; and

a control mechanism for controlling a pressure on the pad at least partially based on a strain output of the strain gage sensor.

2. The apparatus according to claim 1 , wherein the wiping cloth is wound around the feed reel and the pad includes a convexly curved surface that is in contact with the wiping cloth if the at least one pair of mechanisms for wiping or tape-cleaning both sides of the magnetic disk wipes both sides of the magnetic disk.

3. The apparatus according to claim 2 , wherein the pad is semi-circular.

4. The apparatus according to claim 2 , wherein the pad comprises an ester-based polyurethane rubber having a hardness of about 20 degrees to about 40 degrees.

5. The apparatus according to claim 2 , wherein the wiping cloth comprises a woven fabric of at least a polyester fiber and a nylon fiber.

6. The apparatus according to claim 1 , wherein the control mechanism detects a strain output from the strain gage sensor, converts the strain output to a corresponding voltage signal, and feeds the signal back to a servomotor to control the pressure of the pad to a predetermined value.

7. The apparatus according to claim 1 , wherein two pairs of mechanisms for wiping or tape-cleaning both sides of the magnetic disk are disposed on either side of the magnetic disk, wherein one is disposed for wiping both sides of the magnetic disk and the other is disposed for tape-cleaning both sides of the magnetic disk.

8. A method for using the apparatus of claim 1 , the method comprising:

forming a lubricant film on the magnetic disk, the magnetic disk having a substrate, at least a magnetic recording film above the substrate, and a protective film above the magnetic recording film;

wiping the lubricant film using the pair of mechanisms for wiping or tap-cleaning while rotating the magnetic disk by pressing the pad against the wiping cloth using the pressure mechanism, wherein the pad has a convexly curved surface in contact with the wiping cloth, and wherein the wiping cloth is disposed so as to oppose the lubricant film; and

using the pressure mechanism to press the cleaning tape which includes abrasive grains against the substrate on which the protective film and lubricant film are formed while rotating the magnetic disk to remove protrusions.

9. The method according to claim 8 , wherein the pad is semi-circular.

10. The method according to claim 8 , wherein a surface of the pad in contact with the wiping cloth has a width of about 1 mm in a traveling direction of the wiping cloth and a width of about 10 mm in a direction perpendicular to the traveling direction of the wiping cloth.

11. The method according to claim 10 , wherein the wiping cloth is about 12.6 mm wide and moved from an inner peripheral side to an outer peripheral side of the substrate.

12. The method according to claim 8 , wherein the pad comprises ester-based polyurethane rubber having a hardness of about 20 degrees to about 40 degrees.

13. The method according to claim 8 , wherein the wiping cloth comprises a woven fabric of at least a polyester fiber and a nylon fiber.

14. The method according to claim 8 , wherein the wiping cloth is pressed against the substrate in a traveling direction of the substrate.

15. The method according to claim 8 , further comprising:

forming at least the magnetic recording film above a substrate; and

forming a protective film above the magnetic recording film.

16. The method according to claim 15 , wherein the forming at least a magnetic recording film above the substrate further includes:

forming a soft magnetic layer above an underlayer; and

forming a magnetic layer on the soft magnetic layer.

17. The method according to claim 8 , wherein the lubricant film is wiped while rotating the substrate at about 3.0 m/s to about 3.5 m/s.

18. The method according to claim 8 , wherein the pad is pressed against a wiping cloth at the loading speed of about 12 mm/min to about 36 mm/min under a pressure of about 3 gf/mm 2 to about 9 gf/mm 2 .

19. A method using the apparatus to of claim 1 , the method comprising:

forming a lubricant film on the magnetic disk, the magnetic disk having a substrate, at least a magnetic recording film above the substrate, and a protective film above the magnetic recording film;

wiping the lubricant film while rotating the magnetic disk on the mechanism for supporting and rotating the magnetic disk at about 3.0 m/s to about 3.5 m/s by pressing the pad against the wiping cloth at a loading speed of about 12 mm/min to about 36 mm/min under a pressure of about 3 gf/mm 2 to about 9 gf/mm 2 , wherein the pad has a convexly curved surface in contact with the wiping cloth, and wherein the wiping cloth is disposed so as to oppose the lubricant film; and

using the pressure mechanism to press the cleaning tape which includes abrasive grains against the substrate on which the protective film and lubricant film are formed while rotating the magnetic disk to remove protrusions.