Patent US4298899A successfully refreshed from Google Patents.
US4298899A
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Magnetic head assembly with ferrite core
Assignee: International Business Machines Corp
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Filing: 1979-12-17
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Granted: 1981-11-03
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Expires: 1999-12-17
Abstract
Abstract A magnetic head assembly includes a ferrite core sandwiched between two ceramic layers. Alumina films are deposited by sputtering on the sides of the ferrite core and on the ceramic layers in one structure, and on the ferrite core only in another structure, which are then bonded to form an integral head assembly. Slots to provide flying height control are formed in the air bearing surface of the ceramic layers. The process of making the assembly includes the steps of sputter etching the ferrite and ceramic prior to the deposition of the alumina.
Inventors
- 👤 Armando J. Argumedo
- 👤 George W. Brock
- 👤 Paul D. Losee
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-31 17:31
CPC Classifications
G; G11; G11B; G11B5/00; G11B5/127; G11B5/187; G11B5/255; G11B5/133; G11B5/1335; G11B5/193; Y; Y10; Y10T; Y10T29/00; Y10T29/49; Y10T29/49002; Y10T29/4902; Y10T29/49021; Y10T29/49032; Y10T29/49036; Y10T29/49041; Y10T29/49055; Y10T29/49057
Claims Analysis
Total Claims: 7
Claim 1
Independent Claim
96 words
A magnetic head assembly including a ferrite core having two sides and a transducing gap between said sides, wherein the improvement comprises: first and second ceramic structures disposed respectively on each side of said core; first and second alumina films disposed on each side of and in contact with said core; third and fourth alumina films deposited respectively on one side of and in contact respectively with said ceramic structures; and means for bonding said first and third alumina films and said second and fourth alumina films to form a sandwich structure around said ferrite core.
Claim 2
Dependent Claim
96 words
A magnetic head assembly including a ferrite core having two sides and a transducing gap between said sides, wherein the improvement comprises: first and second ceramic structures disposed respectively on each side of said core; first and second alumina films disposed on each side of and in contact with said core; third and fourth alumina films deposited respectively on one side of and in contact respectively with said ceramic structures; and means for bonding said first and third alumina films and said second and fourth alumina films to form a sandwich structure around said ferrite core.
Claim 3
Dependent Claim
24 words
A magnetic head assembly as in claim 1, wherein said alumina films are sputter deposited on said ferrite core and on said ceramic structures.
Claim 4
Dependent Claim
17 words
A magnetic head assembly as in claim 1, wherein said bonding means comprises a glass or epoxy.
Claim 5
Dependent Claim
17 words
A magnetic head assembly as in claim 1, wherein said ceramic structures are formed from barium titanate.
Claim 6
Dependent Claim
18 words
A magnetic head assembly as in claim 1, wherein said sandwich configuration has a contoured air bearing surface.
Claim 7
Dependent Claim
20 words
A magnetic head assembly as in claim 5, wherein said air bearing surface comprises slotted portions in said ceramic structures.
References Cited (Backward Citations)
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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) | 1984-11-02 | 1985-05-04 | 1985-11-03 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1988-11-02 | 1989-05-04 | 1989-11-03 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1992-11-02 | 1993-05-04 | 1993-11-03 | $7700.00 | Window Closed / Lapsed |