Claims
- 1. A method of manufacturing a magnetic recording medium, comprising the steps of:(a) preparing a sol solution containing solvent and gel particles; (b) treating said sol solution to remove therefrom gel particles having a size greater than a predetermined maximum size; (c) providing a non-magnetic substrate for a magnetic recording medium, said substrate including at least one surface; (d) applying a layer of the treated sol solution to said at least one surface of said substrate; (e) converting said layer of treated sol solution to a layer of sol-gel having a hardness less than that of said at least one surface of said substrate, an exposed surface of said layer of sol-gel having substantially no defects in the form of protrusions or bumps; (f) forming a pattern in said exposed surface of said layer of sol-gel; and (g) converting said layer of sol-gel to a layer having a density and hardness substantially comparable to that of said at least one surface of said substrate, while preserving said pattern formed in step (f).
- 2. The method according to claim 1, wherein:step (a) comprises forming a silica (SiO2) sol solution containing SiO2 gel particles.
- 3. The method according to claim 2, wherein:step (a) further comprises removing heat generated during said preparing from said sol solution to minimize formation of large SiO2 gel particles.
- 4. The method according to claim 1, wherein:step (b) comprises treating said sol solution to remove gel particles having a size greater than about 5 μm.
- 5. The method according to claim 4, wherein:step (b) comprises passing said sol solution through a depth filter having a pore size of about 5 μm.
- 6. The method according to claim 4, wherein:step (b) comprises treating said sol solution by ultra-centrifugation at a G-force greater than about 50,000 G and a spin speed greater than about 10,000 rpm.
- 7. The method according to claim 1, wherein:step (c) comprises providing a disk-shaped substrate formed of a glass, ceramic, or glass-ceramic material.
- 8. The method according to claim 1, wherein:step (d) comprises applying said layer of said treated sol solution to said at least one surface of said substrate by spin-coating.
- 9. The method according to claim 1, wherein:step (e) comprises converting said layer of treated sol solution into said layer of sol-gel by removing a portion of the solvent(s) contained in said layer of treated sol solution; step (f) comprises mechanically embossing a servo pattern in said exposed surface of said layer of sol-gel; and step (g) comprises forming said glass or glass-like layer by substantially completely removing said solvent(s) from said layer of sol-gel.
- 10. The method according to claim 9, wherein:step (e) comprises removing a portion of said solvent(s) contained in said layer of treated sol-gel solution during said step (d) of applying said layer of treated sol solution to said at least one surface of said substrate; step (f) comprises mechanically embossing said servo pattern in said exposed surface of said layer of sol-gel by applying thereto a surface of a stamper, said surface of said stamper including a negative image pattern of said servo pattern; and step (g) comprises substantially completely removing said solvent(s) from said layer of sol-gel by sintering said layer of sol-gel at an elevated temperature for a predetermined interval.
- 11. The method according to claim 1, further comprising the step of:(h) forming a stack of thin film layers over an exposed surface of said glass or glass-like layer formed in step (g), said stack of layers including at least one ferromagnetic layer.
CROSS-REFERENCE TO PROVISIONAL APPLICATIONS
This application claims priority from U.S. provisional patent application Ser. Nos. 60/221,219; 60/221,259; and 60/221,460, each filed Jul. 25, 2000, the entire disclosures of which are incorporated herein by reference.
US Referenced Citations (16)
Provisional Applications (3)
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Number |
Date |
Country |
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60/221219 |
Jul 2000 |
US |
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60/221259 |
Jul 2000 |
US |
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60/221460 |
Jul 2000 |
US |