US4841399A
Expired / Lapsed
US
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Magnetoresistive magnetic head including zirconium sheet film
Assignee: Hitachi Ltd
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Filing: 1986-12-01
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Granted: 1989-06-20
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Expires: 2006-12-01
Abstract
Abstract The use of a pure zirconium film as a shunt film in a magnetoresistive head having a permalloy film as a magnetoresistive film and a shunt film for application of a transverse biasing magnetic field serves to improve the heat resistance of the magnetoresistive element and allows an increase in the temperature used in the process for producing a magnetic head.
Inventors
- 👤 Masahiro Kitada
- 👤 Noboru Shimizu
- 👤 Hideo Tanabe
- 👤 Hitoshi Nakamura
- 👤 Tetsuo Kobayashi
- 👤 Tooru Takeura
- 👤 Kazuhiro Momata
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-08 22:12
CPC Classifications
G; G11; G11B; G11B5/00; G11B5/127; G11B5/33; G11B5/39; G11B5/3903; G11B5/399
Claims Analysis
Total Claims: 11
Claim 1
Independent Claim
45 words
A magnetoresistive magnetic head comprising a two-layer film structure consisting of i) a magnetoresistive film comprised of a Ni-Fe alloy film containing 7 to 27 wt % of iron and substantially the balance of nickel and ii) a shunt film comprised of a zirconium film.
Claim 2
Dependent Claim
45 words
A magnetoresistive magnetic head comprising a two-layer film structure consisting of i) a magnetoresistive film comprised of a Ni-Fe alloy film containing 7 to 27 wt % of iron and substantially the balance of nickel and ii) a shunt film comprised of a zirconium film.
Claim 3
Dependent Claim
20 words
A magnetoresistive magnetic head according to claim 1, wherein said zirconium film has a thickness of 125 to 5000 Å.
Claim 4
Dependent Claim
20 words
A magnetoresistive magnetic head according to claim 2, wherein said magnetoresistive film has a thickness of 50 to 1,000 Å.
Claim 5
Dependent Claim
20 words
A magnetoresistive magnetic head according to claim 1, wherein said zirconium film has a thickness of 750 to 2500 Å.
Claim 6
Dependent Claim
25 words
A magnetoresistive magnetic head according to claim 1, wherein said zirconium film has a thickness 2.5 to 5 times that of said Ni-Fe alloy film.
Claim 7
Dependent Claim
20 words
A magnetoresistive magnetic head according to claim 1, wherein said magnetoresistive film has a thickness of 300 to 500 Å.
Claim 8
Dependent Claim
20 words
A magnetoresistive magnetic head according to claim 1, further comprising a substrate on which said two-layer film structure is provided.
Claim 9
Dependent Claim
18 words
A magnetoresistive magnetic head according to claim 7, wherein said substrate is made of a soft magnetic material.
Claim 10
Dependent Claim
29 words
A magnetoresistive magnetic head according to claim 8, wherein said soft magnetic material is Ni-Zn ferrite and an insulating film is provided between said substrate and said two-layer film.
Claim 11
Dependent Claim
34 words
A magnetoresistive magnetic head according to claim 7, wherein a block of soft magnetic material is provided on a side of said two-layer film structure opposite a side on which said substrate is provided.
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) | 1992-06-19 | 1992-12-19 | 1993-06-20 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1996-06-19 | 1996-12-19 | 1997-06-20 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2000-06-19 | 2000-12-19 | 2001-06-20 | $7700.00 | Window Closed / Lapsed |