US4517616A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Thin film magnetic recording transducer having embedded pole piece design
Assignee: Unisys Corp
•
Filing: 1983-03-28
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Granted: 1985-05-14
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Expires: 2003-03-28
Abstract
Abstract The subject invention relates to the fabrication of metal oxide patterns on a substrate adapted for use with thin film magnetic heads. The metal oxide pattern has a precisely defined geometry including nearly vertical side walls, for minimizing read/write errors. In addition, a filler material formed from a non-magnetic, non-metallic compound is provided on the substrate in a pattern complimentary to the metal oxide pattern. In accordance with the subject invention, the top surface of the metal oxide pattern and the filler material are co-planar. By this arrangement, subsequent layers may be uniformly deposited without discontinuities. The subject method includes a plurality of distinct masking and etching steps in order to achieve the desired result.
Inventors
- 👤 Peter G. Bischoff
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-31 23:41
CPC Classifications
H; H01; H01F; H01F41/00; H01F41/32; H01F41/34; G; G11; G11B; G11B5/00; G11B5/127; G11B5/31; G11B5/3163; Y; Y10; Y10S; Y10S428/00; Y10S428/90; Y10T; Y10T428/00; Y10T428/11; Y10T428/1171; Y10T428/1186; Y10T428/24; Y10T428/24479; Y10T428/24521; Y10T428/24545
Claims Analysis
Total Claims: 6
Claim 1
Independent Claim
85 words
In an improved thin film magnetic recording transducer comprising a thin film magnetic transducer metal deployed in a pattern adapted for magnetic read/write operations, wherein the improvement comprises that said pattern is disposed in associated depressions in the surface of a layer of non-magnetic, non-conductive dielectric material, said depressions being formed to exhibit sidewalls which are orthogonal to the dielectric surface, the magnetic transducer metal filling said depressions wherein the exposed surface of the metal is effectively coplanar with the surface of the dielectric material.
Claim 2
Dependent Claim
85 words
In an improved thin film magnetic recording transducer comprising a thin film magnetic transducer metal deployed in a pattern adapted for magnetic read/write operations, wherein the improvement comprises that said pattern is disposed in associated depressions in the surface of a layer of non-magnetic, non-conductive dielectric material, said depressions being formed to exhibit sidewalls which are orthogonal to the dielectric surface, the magnetic transducer metal filling said depressions wherein the exposed surface of the metal is effectively coplanar with the surface of the dielectric material.
Claim 3
Dependent Claim
17 words
The transducer as recited in claim 1 wherein said dielectric material is deposited on a non-magnetic substrate.
Claim 4
Dependent Claim
16 words
The transducer as recited in claim 2 wherein the magnetic metal comprises an alloy of Ni-Fe.
Claim 5
Dependent Claim
31 words
The transducer as recited in claim 3 wherein the dielectric layer is selected from the group consisting of SiO 2 , Si 3 N 4 and Al 2 O 3 .
Claim 6
Dependent Claim
30 words
The transducer as recited in claim 4 wherein the dielectric material is SiO 2 or Al 2 O 3 and the thickness of the dielectric material is a few microns.
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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) | 1988-05-13 | 1988-11-12 | 1989-05-14 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1992-05-13 | 1992-11-12 | 1993-05-14 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1996-05-13 | 1996-11-12 | 1997-05-14 | $7700.00 | Window Closed / Lapsed |