US4789910A
Expired / Lapsed
US
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Thin film magnetic head with an application type silicon dioxide film
Assignee: Sharp Corp
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Filing: 1986-04-25
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Granted: 1988-12-06
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Expires: 2006-04-25
Abstract
Abstract A thin film magnetic head which comprises an end portion of a first yoke and an end portion of a second yoke confronting each other through a magnetic gap, and receiving from a recording surface or a recording medium, a magnetic signal, and a magnetic reluctance effect element disposed for magnetic coupling in the course of a magnetic path constituted by the first and second yokes. The thin film magnetic head is characterized in that the first yoke or magnetic reluctance effect element is formed on an application type SiO 2 film which improves the surface roughness of the ground layer.
Inventors
- 👤 Kozi Otsuka
- 👤 Tohru Kira
- 👤 Kazuyoshi Imae
- 👤 Mitsuhiko Yoshikawa
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-04 10:22
CPC Classifications
G; G11; G11B; G11B5/00; G11B5/127; G11B5/33; G11B5/39; G11B5/3903
Claims Analysis
Total Claims: 24
Claim 1
Independent Claim
129 words
A thin film magnetic head for reading a magnetic signal from a magnetic recording medium comprising: a first yoke having a first yoke end portion; a second yoke being a second yoke end portion; said first and second yoke end portions forming a magnetic gap therebetween; said second yoke receiving the magnetic signal from the magnetic recording medium; magnetic reluctance effect means, for magnetically coupling a magnetic path between said first and second yokes; a ground layer for supporting said first yoke, said second yoke and said magnetic reluctance effect means; and application type silicon dioxide film means formed directly on said ground layer, for smoothing surface roughness of said ground layer; said magnetic reluctance effect means or said first yoke being formed on said application type silicon dioxide.
Claim 2
Dependent Claim
129 words
A thin film magnetic head for reading a magnetic signal from a magnetic recording medium comprising: a first yoke having a first yoke end portion; a second yoke being a second yoke end portion; said first and second yoke end portions forming a magnetic gap therebetween; said second yoke receiving the magnetic signal from the magnetic recording medium; magnetic reluctance effect means, for magnetically coupling a magnetic path between said first and second yokes; a ground layer for supporting said first yoke, said second yoke and said magnetic reluctance effect means; and application type silicon dioxide film means formed directly on said ground layer, for smoothing surface roughness of said ground layer; said magnetic reluctance effect means or said first yoke being formed on said application type silicon dioxide.
Claim 3
Dependent Claim
28 words
The thin film magnetic head as claimed in claim 1, wherein said application type silicon dioxide film is formed by spinning the silicon dioxide onto said ground layer.
Claim 4
Dependent Claim
24 words
The thin film magnetic head as claimed in claim 1, wherein said smooth surface roughness of said ground layer is less than 10 Å.
Claim 5
Dependent Claim
28 words
The thin film magnetic head as claimed in claim 1, wherein said smooth surface roughness of said ground layer reduces magnetic resistance in the thin film magnetic head.
Claim 6
Dependent Claim
143 words
A thin film magnetic head for receiving a magnetic signal from a magnetic recording medium comprising: a first yoke; a second yoke; said first and second yokes forming a magnetic gap therebetween; magnetic reluctance effect means, for magnetically coupling a magnetic path formed by said first and second yokes, having unaxial magnetic anisotrophy; said first yoke, and said second yoke and said magnetic reluctance effect means forming an arrangement for detecting variations in the magnetic signal applied in a direction of a difficult axis to magnetize, said variation being a variation in magnetic resistance; a substrate, for providing support to said first yoke and said second yoke and said magnetic reluctance effect means; an insulating layer formed on said substrate; and application type silicon dioxide film formed on said insulating layer, said application type silicon dioxide film smoothing surface roughness of said substrate.
Claim 7
Dependent Claim
143 words
A thin film magnetic head for receiving a magnetic signal from a magnetic recording medium comprising: a first yoke; a second yoke; said first and second yokes forming a magnetic gap therebetween; magnetic reluctance effect means, for magnetically coupling a magnetic path formed by said first and second yokes, having unaxial magnetic anisotrophy; said first yoke, and said second yoke and said magnetic reluctance effect means forming an arrangement for detecting variations in the magnetic signal applied in a direction of a difficult axis to magnetize, said variation being a variation in magnetic resistance; a substrate, for providing support to said first yoke and said second yoke and said magnetic reluctance effect means; an insulating layer formed on said substrate; and application type silicon dioxide film formed on said insulating layer, said application type silicon dioxide film smoothing surface roughness of said substrate.
Claim 8
Dependent Claim
28 words
The thin film magnetic head as claimed in claim 5, wherein said application type silicon dioxide film is formed by spinning the silicon dioxide onto said insulating layer.
Claim 9
Dependent Claim
21 words
The thin film magnetic head as claimed in claim 5, wherein said magnetic reluctance effect means comprises a ferromagnetic thin film.
Claim 10
Dependent Claim
22 words
The thin film magnetic head as claimed in claim 5, wherein said smooth surface of said substrate is less than 10 Å.
Claim 11
Dependent Claim
28 words
The thin film magnetic head as claimed in claim 5, wherein said smooth surface roughness of said insulating layer reduces magnetic resistance in the thin film magnetic head.
Claim 12
Dependent Claim
144 words
A thin film magnetic head for receiving a magnetic signal comprising: a substrate; an application type silicon dioxide film formed on said substrate; a lower yoke of a high permeability magnetic film formed on said application type silicon dioxide film; a first insulating layer formed on said lower yoke; a conductor layer formed on said first insulating layer; a second insulating layer formed on said conductor layer; a magnetic reluctance effect element and lead layer formed on said second insulating layer; a third insulating layer formed on said magnetic reluctance effect element and said lead layer; an upper yoke formed on said third insulating layer; and a back yoke portion formed between said upper yoke and said lower yoke; said upper yoke and said back yoke forming a magnetic gap portion therebetween; said application type silicon dioxide film smoothing surface roughness of said substrate.
Claim 13
Dependent Claim
144 words
A thin film magnetic head for receiving a magnetic signal comprising: a substrate; an application type silicon dioxide film formed on said substrate; a lower yoke of a high permeability magnetic film formed on said application type silicon dioxide film; a first insulating layer formed on said lower yoke; a conductor layer formed on said first insulating layer; a second insulating layer formed on said conductor layer; a magnetic reluctance effect element and lead layer formed on said second insulating layer; a third insulating layer formed on said magnetic reluctance effect element and said lead layer; an upper yoke formed on said third insulating layer; and a back yoke portion formed between said upper yoke and said lower yoke; said upper yoke and said back yoke forming a magnetic gap portion therebetween; said application type silicon dioxide film smoothing surface roughness of said substrate.
Claim 14
Dependent Claim
27 words
The thin film magnetic head as claimed in claim 10, wherein said application type silicon dioxide film is formed by spinning the silicon dioxide onto said substrate.
Claim 15
Dependent Claim
21 words
The thin film magnetic head as claimed in claim 10, wherein said magnetic reluctance effect element comprises a ferromagnetic thin film.
Claim 16
Dependent Claim
22 words
The thin film magnetic head as claimed in claim 10, wherein said smooth surface of said substrate is less than 10 Å.
Claim 17
Dependent Claim
27 words
The thin film magnetic head as claimed in claim 10, wherein said smooth surface roughness of said substrate reduces magnetic resistance in the thin film magnetic head.
Claim 18
Dependent Claim
131 words
A thin film magnetic head for receiving a magnetic signal comprising: a substrate; a first insulating layer formed on said substrate; a conductor layer, for applying a magnetic bias, formed on said first insulating layer; a second insulating layer formed on said conductor layer; application type silicon dioxide film formed on said second insulating layer; a magnetic reluctance effect element and lead layer formed on said application type silicon dioxide film; a third insulating layer formed on said magnetic reluctance effect element and said lead layer; a first yoke formed on said third insulating layer; and a second yoke formed between said first yoke and said substrate; said first yoke and said second yoke forming a magnetic gap therebetween; said application type silicon dioxide film smoothing surface roughness of said substrate.
Claim 19
Dependent Claim
131 words
A thin film magnetic head for receiving a magnetic signal comprising: a substrate; a first insulating layer formed on said substrate; a conductor layer, for applying a magnetic bias, formed on said first insulating layer; a second insulating layer formed on said conductor layer; application type silicon dioxide film formed on said second insulating layer; a magnetic reluctance effect element and lead layer formed on said application type silicon dioxide film; a third insulating layer formed on said magnetic reluctance effect element and said lead layer; a first yoke formed on said third insulating layer; and a second yoke formed between said first yoke and said substrate; said first yoke and said second yoke forming a magnetic gap therebetween; said application type silicon dioxide film smoothing surface roughness of said substrate.
Claim 20
Dependent Claim
24 words
The thin film magnetic head as claimed in claim 15, further comprising a third yoke, forming between said substrate in said first insulating layer.
Claim 21
Dependent Claim
27 words
The thin film magnetic head as claimed in claim 15, wherein said application type silicon dioxide film is formed by spinning the silicon dioxide onto said substrate.
Claim 22
Dependent Claim
21 words
The thin film magnetic head as claimed in claim 15, wherein said magnetic reluctance effect element comprises a ferromagnetic thin film.
Claim 23
Dependent Claim
22 words
The thin film magnetic head as claimed in claim 15, wherein said smooth surface of said substrate is less than 10 Å.
Claim 24
Dependent Claim
27 words
The thin film magnetic head as claimed in claim 15, wherein said smooth surface roughness of said insulating layer reduces magnetic resistance in the thin film head.
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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) | 1991-12-06 | 1992-06-06 | 1992-12-06 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1995-12-06 | 1996-06-06 | 1996-12-06 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1999-12-06 | 2000-06-06 | 2000-12-06 | $7700.00 | Window Closed / Lapsed |