US3970433A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Recording surface substrate
Assignee: Seagate Technology LLC
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Filing: 1975-06-23
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Granted: 1976-07-20
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Expires: 1995-06-23
Abstract
Abstract An improved substrate on which a cobalt-magnetic recording layer may be plated and a method for producing it. The substrate includes inner and outer nickel layers with an intermediate gold layer between them. This results in a smooth surface on which a uniform and adherent cobalt recording layer can be deposited.
Inventors
- 👤 Gary Paul Warmka
- 👤 James Dan Hill
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-29 05:40
CPC Classifications
H; H01; H01F; H01F10/00; H01F10/26; H01F10/28; C; C25; C25D; C25D5/00; C25D5/60; C25D5/605; C25D5/611; C25D5/623; Y; Y10; Y10S; Y10S428/00; Y10S428/922; Y10S428/923; Y10S428/924; Y10S428/926; Y10S428/9335; Y10S428/936; Y10T; Y10T428/00; Y10T428/12; Y10T428/12493; Y10T428/12736; Y10T428/12743; Y10T428/12771; Y10T428/12785; Y10T428/12792; Y10T428/12861; Y10T428/12889; Y10T428/12944
Claims Analysis
Total Claims: 9
Claim 1
Independent Claim
86 words
An improved substrate providing an area on which a cobalt magnetic recording layer may be plated, comprising: a. an inner non-magnetic polished nickel layer on the area; b. a deposited gold layer on the inner nickel layer sufficiently thick to eliminate non-uniformity thereof and sufficiently thin to substantially maintain the smoothness of the inner nickel layer; and c. an outer non-magnetic deposited nickel layer on the gold layer sufficiently thick to eliminate porosity therein and sufficiently thin to substantially maintain the smoothness of the gold layer.
Claim 2
Dependent Claim
86 words
An improved substrate providing an area on which a cobalt magnetic recording layer may be plated, comprising: a. an inner non-magnetic polished nickel layer on the area; b. a deposited gold layer on the inner nickel layer sufficiently thick to eliminate non-uniformity thereof and sufficiently thin to substantially maintain the smoothness of the inner nickel layer; and c. an outer non-magnetic deposited nickel layer on the gold layer sufficiently thick to eliminate porosity therein and sufficiently thin to substantially maintain the smoothness of the gold layer.
Claim 3
Dependent Claim
16 words
The substrate of claim 1, wherein the gold layer is no thinner than approximately 3 microinches.
Claim 4
Dependent Claim
16 words
The substrate of claim 2, wherein the gold layer is no thicker than approximately 5 microinches.
Claim 5
Dependent Claim
17 words
The substrate of claim 1, wherein the outer nickel layer is no thinner than approximately 5 microinches.
Claim 6
Dependent Claim
17 words
The substrate of claim 4, wherein the outer nickel layer is no thicker than approximately 15 microinches.
Claim 7
Dependent Claim
17 words
The substrate of claim 1, wherein the inner nickel layer is a nearly specularly polished nickel layer.
Claim 8
Dependent Claim
14 words
The substrate of claim 1, wherein the gold layer is an electrolytically deposited layer.
Claim 9
Dependent Claim
33 words
The substrate of claim 7, wherein the gold layer is in the range of 3 to 5 microinches thick, and the outer nickel layer is in the range of 5 to 15 microinches.
References Cited (Backward Citations)
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1979-07-20 | 1980-01-19 | 1980-07-20 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1983-07-20 | 1984-01-19 | 1984-07-20 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1987-07-20 | 1988-01-19 | 1988-07-20 | $7700.00 | Window Closed / Lapsed |