US5087481A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Method for texturing a magnetic disk silicate glass substrate
Assignee: AGC Inc
•
Filing: 1989-03-29
•
Granted: 1992-02-11
•
Expires: 2009-03-29
Abstract
Abstract A glass disk is subjected to a chemical or gentle mechanical polishing step to remove microcracks or scratches in the disk surface prior to chemically texturing the disk. Thereafter, magnetic media is deposited onto the glass disk. We have discovered that by performing this pre-texturing polishing step, we can avoid the phenomenon of "linkage bumps," which could otherwise cause the resulting magnetic disk to fail a glide-type test or to cause a read/write head crash.
Inventors
- 👤 Tu Chen
- 👤 Toru Iseda
- 👤 Kazuo Mannami
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-07 03:17
CPC Classifications
G; G11; G11B; G11B5/00; G11B5/62; G11B5/73; G11B5/739; G11B5/73911; G11B5/73921; G11B5/7368; Y; Y10; Y10S; Y10S428/00; Y10S428/90; Y10T; Y10T428/00; Y10T428/24; Y10T428/24355
Claims Analysis
Total Claims: 18
Claim 1
Independent Claim
52 words
A method for texturing a silicate glass substrate used to manufacture a magnetic disk comprising the steps of: subjecting said substrate to a polishing step to eliminate or substantially reduce the number of microcracks in the surface of said substrate; and texturing said substrate by subjecting said substrate to a chemical etchant.
Claim 2
Independent Claim
52 words
A method for texturing a silicate glass substrate used to manufacture a magnetic disk comprising the steps of: subjecting said substrate to a polishing step to eliminate or substantially reduce the number of microcracks in the surface of said substrate; and texturing said substrate by subjecting said substrate to a chemical etchant.
Claim 3
Dependent Claim
13 words
Method of claim 1 wherein said polishing step is a mechanical polishing step.
Claim 4
Dependent Claim
13 words
Method of claim 1 wherein said polishing step is a chemical polishing step.
Claim 5
Dependent Claim
18 words
Method of claim 3 wherein said polishing step is a chemical polishing step following a mechanical polishing step.
Claim 6
Dependent Claim
28 words
Method of claim 3 wherein said step of chemical polishing comprises the step of etching said substrate to a depth less than or equal to about 1 μm.
Claim 7
Dependent Claim
24 words
Method of claim 1 wherein said texturing step comprises the step of contacting an aqueous solution containing a fluorine compound to the substrate surface.
Claim 8
Dependent Claim
22 words
Method of claim 1 wherein said texturing step comprises the step of contacting a gas containing hydrogen fluoride to the substrate surface.
Claim 9
Dependent Claim
22 words
Method of claim 1 wherein said polishing step prevents substantially all linkage bumps having heights greater than about 500 Å from forming.
Claim 10
Dependent Claim
22 words
Method of claim 1 further comprising the step of depositing a magnetic alloy film on said substrate after said step of texturing.
Claim 11
Dependent Claim
26 words
Method of claim 9 further comprising the step of depositing a non-magnetic underlayer on said substrate prior to said step of depositing a magnetic alloy film.
Claim 12
Dependent Claim
24 words
Method of claim 1 further comprising the step of washing said substrate prior to said step of subjecting said substrate to said polishing step.
Claim 13
Dependent Claim
22 words
Method of claim 11 further comprising the step of depositing a magnetic alloy film on said substrate after said step of texturing.
Claim 14
Dependent Claim
26 words
Method of claim 12 further comprising the step of depositing a non-magnetic underlayer on said substrate prior to said step of depositing a magnetic alloy film.
Claim 15
Dependent Claim
43 words
Method of claim 1 wherein said step of subjecting said substrate to a polishing step comprises the step of placing said substrate in a pre-etching solution comprising 0.01 to 10 wt. % H 2 SO 4 and 0.01 to 1 wt % HF.
Claim 16
Dependent Claim
49 words
Method of claim 1 wherein said step of subjecting said substrate to a polishing step comprises the step of mechanically polishing said substrate with polishing particles having an average diameter less than or equal to about one micron, under a pressure of about 30 to 70 grams/cm 2 .
Claim 17
Dependent Claim
45 words
Method of claim 1 wherein said step of subjecting said substrate to a polishing step comprises the step of immersing said substrate in a solution comprising a material selected from the group consisting of NaOH, NH 4 F, HF, and H 2 SiF 6 .
Claim 18
Dependent Claim
25 words
Method of claim 1 wherein said step of subjecting said substrate to a polishing step comprises the step of substantially eliminating microcracks from said substrate.
References Cited (Backward Citations)
US3938978A
Cited
US4274907A
Cited
JPS6226623A
Cited
GB2179486A
Cited
JPS62252517A
Cited
US4833001A
Cited
EP0263512B1
Cited
JPS63160013A
Cited
US4876117A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1995-02-10 | 1995-08-12 | 1996-02-11 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1999-02-10 | 1999-08-12 | 2000-02-11 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2003-02-10 | 2003-08-12 | 2004-02-11 | $7700.00 | Window Closed / Lapsed |