US5225951A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Thin film magnetic head with reduced internal stresses
Assignee: Sharp Corp
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Filing: 1992-04-16
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Granted: 1993-07-06
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Expires: 2012-04-16
Abstract
Abstract A thin film magnetic head includes yokes for leading magnetic flux of signals generated from a magnetic recording medium up to a magnetic resistance effect element. The yokes are made of sputtered films having internal compressive stress therein. The internal stress in the yokes which are deleterious to the magnetic properties of the magnetic resistance effect element can be negated or reduced by including a film of material on the yokes for compensating for the internal stresses.
Inventors
- 👤 Tohru Kira
- 👤 Kozi Otsuka
- 👤 Kazuyoshi Imae
- 👤 Mitsuhiko Yoshikawa
- 👤 Kengo Shiiba
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-03 12:58
CPC Classifications
G; G11; G11B; G11B5/00; G11B5/127; G11B5/33; G11B5/39; G11B5/3903; G11B5/3906; G11B5/3916; G11B5/3919; G11B5/3922; G11B5/3925; G11B5/31; G11B5/3109; G11B5/3113
Claims Analysis
Total Claims: 10
Claim 1
Independent Claim
103 words
A thin film magnetic head comprising: a magneto-resistive element; a plurality of yokes, each one of said yokes formed of a sputtered film with residual compressive stress contained therein and operatively connected to said magneto-resistive element for leading magnetic flux of signals from a magnetic recording medium to said magneto-resistive element; and a high melting point film coated on each of the sputtered films, the high melting point film having a residual tensile stress approximately equal to the residual compressive stress in the sputtered film, so that residual stresses in the magneto resistive element are reduced resulting in a reduction in Barkausen noise.
Claim 2
Dependent Claim
103 words
A thin film magnetic head comprising: a magneto-resistive element; a plurality of yokes, each one of said yokes formed of a sputtered film with residual compressive stress contained therein and operatively connected to said magneto-resistive element for leading magnetic flux of signals from a magnetic recording medium to said magneto-resistive element; and a high melting point film coated on each of the sputtered films, the high melting point film having a residual tensile stress approximately equal to the residual compressive stress in the sputtered film, so that residual stresses in the magneto resistive element are reduced resulting in a reduction in Barkausen noise.
Claim 3
Dependent Claim
76 words
A thin film magnetic head comprising: a magneto-resistive element; at least one yoke, formed of a first film, with residual stresses operatively connected to the magneto-resistive element for leading magnetic flux, to said magneto-resistive element; said first film being coated with a film having an internal stress value effective for reducing the influence of residual stresses in the first film, so that the residual stresses do not effect the magneto-resistive element and Barkhausen noises are reduced.
Claim 4
Dependent Claim
76 words
A thin film magnetic head comprising: a magneto-resistive element; at least one yoke, formed of a first film, with residual stresses operatively connected to the magneto-resistive element for leading magnetic flux, to said magneto-resistive element; said first film being coated with a film having an internal stress value effective for reducing the influence of residual stresses in the first film, so that the residual stresses do not effect the magneto-resistive element and Barkhausen noises are reduced.
Claim 5
Dependent Claim
59 words
A thin film magnetic head comprising: a first yoke; a second yoke; a magneto-resistive element formed of a material having a magnetostriction constant of a positive value; said yokes and magneto-resistive element formed of ferromagnetic thin films and magnetically connected to each other; said first and second yokes having negative internal compressive stresses, so that Barkhausen noises are reduced.
Claim 6
Dependent Claim
59 words
A thin film magnetic head comprising: a first yoke; a second yoke; a magneto-resistive element formed of a material having a magnetostriction constant of a positive value; said yokes and magneto-resistive element formed of ferromagnetic thin films and magnetically connected to each other; said first and second yokes having negative internal compressive stresses, so that Barkhausen noises are reduced.
Claim 7
Dependent Claim
22 words
A thin film magnetic head claimed in claim 3, wherein there is an insulation film between the yokes and the magneto-resistive element.
Claim 8
Dependent Claim
60 words
A thin film magnetic head comprising: a first yoke; a second yoke; a magneto-resistive element formed of a material having a magnetostriction constant of a negative value; said yokes and magneto-resistive element formed of ferro magnetic thin films and magnetically connected to each other said first and second yokes having positive internal tensile stresses so that Barkhausen noises are reduced.
Claim 9
Dependent Claim
60 words
A thin film magnetic head comprising: a first yoke; a second yoke; a magneto-resistive element formed of a material having a magnetostriction constant of a negative value; said yokes and magneto-resistive element formed of ferro magnetic thin films and magnetically connected to each other said first and second yokes having positive internal tensile stresses so that Barkhausen noises are reduced.
Claim 10
Dependent Claim
21 words
A thin film magnetic head claimed in claim 5, there is an insulation film between the yokes and the magneto-resistive element.
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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) | 1996-07-05 | 1997-01-04 | 1997-07-06 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 2000-07-05 | 2001-01-04 | 2001-07-06 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2004-07-05 | 2005-01-04 | 2005-07-06 | $7700.00 | Window Closed / Lapsed |