US4552820A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Disc media
Assignee: LIN DATA Corp 2005 de la CRUZ BLVD STE 210 SANTA CLRA CA 95050 A CA CORP
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Filing: 1984-04-25
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Granted: 1985-11-12
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Expires: 2004-04-25
Abstract
Abstract A thin-film disc fabrication method and structure contemplates a sputtered undercoat. An aluminum base is subjected to a fine polishing step, and a relatively thin undercoat is deposited by sputtering. The preferred undercoat is a 0.3-3 micron layer of nickel-vanadium alloy (on the order of 7% vanadium). The preferred recording layer is a sputtered composite structure comprising a layer of chromium and an overlying layer of a cobalt-chromium alloy. Modulation effects can be substantially eliminated by heating the aluminum base prior to sputtering the nickel-vanadium undercoat, and by oxidizing the undercoat prior to deposition of the overlying layers.
Inventors
- 👤 Yeong S. Lin
- 👤 Nathan T. Ballard
- 👤 John T. Lee
- 👤 Edward F. Teng
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-23 17:24
CPC Classifications
G; G11; G11B; G11B5/00; G11B5/62; G11B5/73; G11B5/7368; G11B5/7371; G11B5/739; G11B5/73911; G11B5/73917; G11B5/73919; G11B5/84; G11B5/851; Y; Y10; Y10S; Y10S428/00; Y10S428/922; Y10S428/9265; Y10S428/928; Y10T; Y10T428/00; Y10T428/12; Y10T428/12465; Y10T428/12493; Y10T428/12736; Y10T428/1275; Y10T428/12771; Y10T428/12806; Y10T428/12826; Y10T428/12847; Y10T428/12854; Y10T428/12861; Y10T428/12944
Claims Analysis
Total Claims: 26
Claim 1
Independent Claim
58 words
A method of fabricating a thin-film disc comprising the steps of: (a) providing a base having a surface roughness less than about 250 Å; (b) sputtering a substantially non-magnetic nickel-vanadium layer to a thickness of no more than approximately 10 microns; and (c) depositing at least one magnetic layer to define the recording medium proper of the disc.
Claim 2
Independent Claim
58 words
A method of fabricating a thin-film disc comprising the steps of: (a) providing a base having a surface roughness less than about 250 Å; (b) sputtering a substantially non-magnetic nickel-vanadium layer to a thickness of no more than approximately 10 microns; and (c) depositing at least one magnetic layer to define the recording medium proper of the disc.
Claim 3
Dependent Claim
26 words
The invention of claim 1 wherein said sputtering step (b) is carried out to provide a layer having a thickness in the range of 0.3-3 microns.
Claim 4
Dependent Claim
21 words
The invention of claim 1 wherein said sputtering step (b) is carried out with a nickel-vanadium target containing about 7% vanadium.
Claim 5
Dependent Claim
19 words
The invention of claim 1 wherein said depositing step (c) includes the step of sputtering at least one layer.
Claim 6
Dependent Claim
37 words
The invention of claim 1 wherein said depositing step (c) comprises the substeps of: (i) sputtering a chromium layer having a thickness of about 500-3000Å; and (ii) sputtering a cobalt-chromium layer having a thickness of about 500-2000Å.
Claim 7
Dependent Claim
23 words
The invention of claim 1, and further comprising the step, carried out after said depositing step (c), of: (d) depositing a wear-resistant overcoat.
Claim 8
Dependent Claim
37 words
The invention of claim 1, and further comprising the step, carried out after said providing step (a) and before said sputtering step (b), of: (d) heating the base to a temperature in excess of about 200° C.
Claim 9
Dependent Claim
33 words
The invention of claim 1, and further comprising the step, carried out after said sputtering step (b) and before said depositing step (c), of: (d) oxidizing an outer portion of the non-magnetic layer.
Claim 10
Independent Claim
60 words
A method of fabricating a thin-film disc comprising the steps of: (a) providing a base having a surface roughness less than about 250 Å; (b) sputtering a substantially non-magnetic nickel-vanadium layer to a thickness of approximately 0.3-3 microns; (c) sputtering at least one magnetic layer to define the recording medium proper of the disc; and (d) depositing a wear-resistant overcoat.
Claim 11
Independent Claim
60 words
A method of fabricating a thin-film disc comprising the steps of: (a) providing a base having a surface roughness less than about 250 Å; (b) sputtering a substantially non-magnetic nickel-vanadium layer to a thickness of approximately 0.3-3 microns; (c) sputtering at least one magnetic layer to define the recording medium proper of the disc; and (d) depositing a wear-resistant overcoat.
Claim 12
Dependent Claim
26 words
The invention of claim 9 wherein said sputtering step (b) is carried out to provide a layer having a thickness in the range of 0.5-1.5 microns.
Claim 13
Dependent Claim
21 words
The invention of claim 9 wherein said sputtering step (b) is carried out with a nickel-vanadium target containing about 7% vanadium.
Claim 14
Independent Claim
72 words
A method of fabricating a thin-film disc comprising the steps of: (a) providing a base having a surface roughness less than about 250 angstroms; (b) sputtering a substantially non-magnetic nickel-vanadium layer to a thickness of about 0.5-1.5 microns; and (c) depositing at least one magnetic layer to define the recording medium proper of the disc; said steps (b) and (c) being carried out in an in-line sequence without any intermediate polishing steps.
Claim 15
Independent Claim
72 words
A method of fabricating a thin-film disc comprising the steps of: (a) providing a base having a surface roughness less than about 250 angstroms; (b) sputtering a substantially non-magnetic nickel-vanadium layer to a thickness of about 0.5-1.5 microns; and (c) depositing at least one magnetic layer to define the recording medium proper of the disc; said steps (b) and (c) being carried out in an in-line sequence without any intermediate polishing steps.
Claim 16
Dependent Claim
37 words
A thin-film disc comprising: a base; a sputtered undercoat of substantially non-magnetic nickel-vanadium alloy deposited on said base; and at least one sputtered magnetic layer overlying said undercoat to define the recording medium proper of the disc.
Claim 17
Dependent Claim
37 words
A thin-film disc comprising: a base; a sputtered undercoat of substantially non-magnetic nickel-vanadium alloy deposited on said base; and at least one sputtered magnetic layer overlying said undercoat to define the recording medium proper of the disc.
Claim 18
Dependent Claim
18 words
The invention of claim 13 wherein said base is aluminum having a roughness less than about 250 Å.
Claim 19
Dependent Claim
17 words
The invention of claim 13 wherein said undercoat has a thickness in the range of 0.3-3 microns.
Claim 20
Dependent Claim
56 words
A thin-film disc comprising: a base having a roughness less than about 250Å; a sputtered undercoat of substantially non-magnetic nickel-vanadium alloy of a thickness in the range of 0.3-3 microns deposited on said base; at least one sputtered magnetic layer overlying said undercoat to define the recording medium proper of the disc; and a wear-resistant overcoat.
Claim 21
Dependent Claim
56 words
A thin-film disc comprising: a base having a roughness less than about 250Å; a sputtered undercoat of substantially non-magnetic nickel-vanadium alloy of a thickness in the range of 0.3-3 microns deposited on said base; at least one sputtered magnetic layer overlying said undercoat to define the recording medium proper of the disc; and a wear-resistant overcoat.
Claim 22
Dependent Claim
17 words
The invention of claim 16 wherein the undercoat has a thickness in the range of 0.5-1.5 microns.
Claim 23
Dependent Claim
13 words
The invention of claim 16 wherein said nickel-vanadium alloy contains about 7% vanadium.
Claim 24
Dependent Claim
55 words
A thin-film disc comprising: a base having a roughness less than about 250 angstroms; a sputtered undercoat of substantially non-magnetic nickel-vanadium alloy having a thickness of approximately 0.5-1.5 microns deposited on said base; at least one sputtered magnetic layer overlying said undercoat to define the recording medium proper of the disc; and a wear-resistant overcoat.
Claim 25
Dependent Claim
55 words
A thin-film disc comprising: a base having a roughness less than about 250 angstroms; a sputtered undercoat of substantially non-magnetic nickel-vanadium alloy having a thickness of approximately 0.5-1.5 microns deposited on said base; at least one sputtered magnetic layer overlying said undercoat to define the recording medium proper of the disc; and a wear-resistant overcoat.
Claim 26
Dependent Claim
14 words
The invention of claim 19 wherein said non-magnetic nickel-vanadium alloy contains about 7% vanadium.
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USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1988-11-11 | 1989-05-13 | 1989-11-12 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1992-11-11 | 1993-05-13 | 1993-11-12 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1996-11-11 | 1997-05-13 | 1997-11-12 | $7700.00 | Window Closed / Lapsed |