US3972786A
Expired / Lapsed
US
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Mechanically enhanced magnetic memory
Assignee: Ampex Systems Corp
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Filing: 1974-06-28
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Granted: 1976-08-03
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Expires: 1994-06-28
Abstract
Abstract An improved thin film magnetic memory device is fabricated by selective mechanical enhancement of the coercive force and anisotropic characteristics of the thin film magnetic material. The enhancement is produced by polishing the substrate with a fine abrasive in a direction parallel to the desired easy axis of magnetization prior to magnetic film deposition.
Inventors
- 👤 Nathan Thomas Ballard
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-28 07:41
CPC Classifications
H; H01; H01F; H01F41/00; H01F41/14; C; C25; C25D; C25D3/00; C25D3/02; C25D3/56; C25D3/562; G; G11; G11C; G11C11/00; G11C11/02; G11C11/14; G11C11/15; G11C11/155; H01F10/00; H01F10/26; H01F10/28; Y; Y10; Y10S; Y10S205/00; Y10S205/922
Claims Analysis
Total Claims: 4
Claim 1
Independent Claim
101 words
A process for making a magnetic memory structure wherein a magnetic film is electrodeposited on a non-magnetic metallic substrate comprising the steps of: a. polishing said substrate, whereby grooves are formed in said substrate parallel to a desired easy axis of magnetization, said grooves occupying an area of 5 to 10 percent of said substrate, b. said grooves being formed with an abrasive having a particle size of from about 0.3 to 10 microns, and c. plating a magnetic film over said grooved substrate, said film having a thickness of from one-third to five times the particle size of said abrasive.
Claim 2
Dependent Claim
101 words
A process for making a magnetic memory structure wherein a magnetic film is electrodeposited on a non-magnetic metallic substrate comprising the steps of: a. polishing said substrate, whereby grooves are formed in said substrate parallel to a desired easy axis of magnetization, said grooves occupying an area of 5 to 10 percent of said substrate, b. said grooves being formed with an abrasive having a particle size of from about 0.3 to 10 microns, and c. plating a magnetic film over said grooved substrate, said film having a thickness of from one-third to five times the particle size of said abrasive.
Claim 3
Dependent Claim
10 words
The process of claim 1 wherein the substrate is copper.
Claim 4
Dependent Claim
15 words
The process of claim 1 wherein the magnetic layer is an electrodeposited layer of Ni-Co.
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) | 1979-08-03 | 1980-02-02 | 1980-08-03 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1983-08-03 | 1984-02-02 | 1984-08-03 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1987-08-03 | 1988-02-02 | 1988-08-03 | $7700.00 | Window Closed / Lapsed |