US5793579A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Thin film magnetic head and process for producing same
Assignee: Sanyo Electric Co Ltd
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Filing: 1996-11-26
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Granted: 1998-08-11
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Expires: 2016-11-26
Abstract
Abstract A process for producing a thin film magnetic head comprises a first step of forming a magnetic layer 20 on the surface of a gap spacer layer 9, a second step of forming on the surface of the magnetic layer 20 a lower resist layer 21 shaped to have a smaller width than an upper core layer 11 when seen from above and forming on the resist layer 21 an upper resist layer 22 projecting outward beyond opposite side faces of the resist layer 21 and shaped in conformity with the shape of the upper core layer 11 when seen from above, a third step of shaping the magnetic layer 20 into the upper core layer 11 by ion beam-etching the magnetic layer 20, and a fourth step of removing the lower resist layer 21 and the upper resist layer 22. The core layer 11 consequently formed has a surface including a pair of curved faces R, R smoothly connecting opposite side faces of the layer 11 with respect to the direction of width of a track to the top face of the layer 11, enabling a protective layer forming step to provide a flawless protective layer 14.
Inventors
- 👤 Tomomi Yamamoto
- 👤 Shinji Kobayashi
- 👤 Naoto Matono
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-04 03:40
CPC Classifications
G; G11; G11B; G11B5/00; G11B5/127; G11B5/31; G11B5/3103; G11B5/3106; G11B5/3109; G11B5/3116; G11B5/313; G11B5/3163
Claims Analysis
Total Claims: 8
Claim 1
Independent Claim
97 words
A thin film magnetic head comprising at least one inductive head element provided on a substrate, the head element comprising a lower core layer, an upper core layer and a gap spacer layer interposed between the core layers, the head element being covered in its entirety with a protective layer, the upper core layer having a surface in contact with the protective layer and including opposite side faces with respect to the direction of width of a track, a top face and a pair of curved faces smoothly connecting the respective side faces to the top face.
Claim 2
Dependent Claim
97 words
A thin film magnetic head comprising at least one inductive head element provided on a substrate, the head element comprising a lower core layer, an upper core layer and a gap spacer layer interposed between the core layers, the head element being covered in its entirety with a protective layer, the upper core layer having a surface in contact with the protective layer and including opposite side faces with respect to the direction of width of a track, a top face and a pair of curved faces smoothly connecting the respective side faces to the top face.
Claim 3
Dependent Claim
116 words
A thin film magnetic head comprising at least one inductive head element provided on a substrate, the head element comprising a coil layer formed above a lower core layer and held between a lower insulating layer and an upper insulating layer, and an upper core layer formed on the upper insulating layer with a gap spacer layer interposed therebetween, the head element being covered in its entirety with a protective layer, the upper core layer being provided, at opposite sides thereof with respect to the direction of width of a track, with a nonmagnetic reinforcing layer over the gap spacer layer, the protective layer being formed over the nonmagnetic reinforcing layer and the upper core layer.
Claim 4
Dependent Claim
116 words
A thin film magnetic head comprising at least one inductive head element provided on a substrate, the head element comprising a coil layer formed above a lower core layer and held between a lower insulating layer and an upper insulating layer, and an upper core layer formed on the upper insulating layer with a gap spacer layer interposed therebetween, the head element being covered in its entirety with a protective layer, the upper core layer being provided, at opposite sides thereof with respect to the direction of width of a track, with a nonmagnetic reinforcing layer over the gap spacer layer, the protective layer being formed over the nonmagnetic reinforcing layer and the upper core layer.
Claim 5
Dependent Claim
160 words
A thin film magnetic head comprising at least one inductive head element provided on a substrate, the head element comprising a coil layer formed above a lower core layer and held between a lower insulating layer and an upper insulating layer, and an upper core layer formed on the upper insulating layer with a gap spacer layer interposed therebetween, the head element being covered in its entirety with a protective layer, the upper core layer having a surface in contact with the protective layer and including opposite side faces with respect to the direction of width of a track, a top face and a pair of curved faces smoothly connecting the respective side faces to the top face, the upper core layer being provided, at opposite sides thereof with respect to the track width direction, with a nonmagnetic reinforcing layer over the gap spacer layer, the protective layer being formed over the nonmagnetic reinforcing layer and the upper core layer.
Claim 6
Dependent Claim
160 words
A thin film magnetic head comprising at least one inductive head element provided on a substrate, the head element comprising a coil layer formed above a lower core layer and held between a lower insulating layer and an upper insulating layer, and an upper core layer formed on the upper insulating layer with a gap spacer layer interposed therebetween, the head element being covered in its entirety with a protective layer, the upper core layer having a surface in contact with the protective layer and including opposite side faces with respect to the direction of width of a track, a top face and a pair of curved faces smoothly connecting the respective side faces to the top face, the upper core layer being provided, at opposite sides thereof with respect to the track width direction, with a nonmagnetic reinforcing layer over the gap spacer layer, the protective layer being formed over the nonmagnetic reinforcing layer and the upper core layer.
Claim 7
Dependent Claim
103 words
A thin film magnetic head comprising at least one inductive head element provided on a substrate, the head element comprising a lower core layer, an upper core layer and a gap spacer layer interposed between the core layers, the head element being covered in its entirety with a protective layer, the upper core layer having a top face in contact with the protective layer and a lower face in contact with the gap spacer layer, the top face extending in parallel to a surface of the gap spacer layer and having a smaller width than the lower face in the track width direction.
Claim 8
Dependent Claim
103 words
A thin film magnetic head comprising at least one inductive head element provided on a substrate, the head element comprising a lower core layer, an upper core layer and a gap spacer layer interposed between the core layers, the head element being covered in its entirety with a protective layer, the upper core layer having a top face in contact with the protective layer and a lower face in contact with the gap spacer layer, the top face extending in parallel to a surface of the gap spacer layer and having a smaller width than the lower face in the track width direction.
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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) | 2001-08-10 | 2002-02-09 | 2002-08-11 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 2005-08-10 | 2006-02-09 | 2006-08-11 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2009-08-10 | 2010-02-09 | 2010-08-11 | $7700.00 | Window Closed / Lapsed |