Patent EP0441581A2 successfully refreshed from Google Patents.
EP0441581A2
Expired / Lapsed
EP
⏱️ 0.0 years remaining
Method for producing magnetic structure
Assignee: International Business Machines Corp
•
Filing: 1991-02-04
•
Granted: —
•
Expires: 2011-02-04
Abstract
Abstract A method for producing a magnetic structure, such as a thin film magnetic head, in which the magnetic and electrical characteristics of magnetic material are tailored to produce magnetic and electrical characteristics in selected localized areas of the magnetic material. In an embodiment, the structure comprises a layer of magnetic material having an overlayer and an underlayer, and the magnetic characteristics of the material are modified by rapid thermal annealing.
Inventors
- 👤 Robert Edward Fontana, Jr.
- 👤 Frances Anne Houle
- 👤 Ching Hwa Tsang
Bibliographic Details
Application Number
—
Jurisdiction
EP
Data Source
google_patents
Last Synchronized
2026-11-05 05:05
CPC Classifications
B; B82; B82Y; B82Y25/00; G; G01; G01R; G01R33/00; G01R33/02; G01R33/06; G01R33/09; G01R33/093; B82Y40/00; G11; G11B; G11B5/00; G11B5/127; G11B5/33; G11B5/39; G11B5/3903; G11B5/3906; G11B5/3929; G11B5/3932; H; H01; H01F; H01F10/00; H01F10/32; H01F10/324; H01F41/00; H01F41/14; H01F41/22; H01F41/30; H01F41/302; H01F41/32; H01F41/34
Claims Analysis
Total Claims: 16
Claim 1
Independent Claim
66 words
A method for producing a magnetic structure comprising the steps of: forming a layered structure comprising an underlayer, a layer of magnetic material, and an overlayer; and supplying thermal energy in an amount sufficient to provide selective interaction between the materials of said overlayer and said underlayer with said layer of magnetic material to produce predetermined magnetic and electrical characteristics in said layer of magnetic material.
Claim 2
Dependent Claim
48 words
Method as claimed in Claim 1 wherein the overlayer comprises a plurality of distinct regions and the supplied thermal energy is to produce predetermined magnetic and electrical characteristics in selected localized areas of the layer of magnetic material determined by characteristics of the distinct regions of the overlayer.
Claim 3
Dependent Claim
52 words
Method as claimed in Claim 1 or Claim 2 wherein the underlayer comprises a plurality of distinct regions and the supplied thermal energy is to produce predetermined magnetic and electrical characteristics in selected localized areas in the layer of magnetic material determined by the characteristics of the distinct regions of the underlayer.
Claim 4
Dependent Claim
16 words
Method as claimed in any preceding claim wherein said thermal energy is produced by a laser.
Claim 5
Dependent Claim
23 words
Method as claimed in any of Claims 1 to 3 wherein said step of supplying thermal energy is effected by a furnace anneal.
Claim 6
Dependent Claim
24 words
Method as claimed in any of Claims 1 to 3 wherein the step of supplying thermal energy is effected by a rapid thermal anneal.
Claim 7
Dependent Claim
17 words
Method as claimed in any preceding claim wherein said thermal energy is varied in magnitude over distance.
Claim 8
Dependent Claim
24 words
Method as claimed in any preceding claim wherein said step of supplying thermal energy is carried out in the presence of a selected fluid.
Claim 9
Dependent Claim
16 words
Method as claimed in any preceding claim wherein said layered structure is formed on a substrate.
Claim 10
Dependent Claim
15 words
Method as claimed in any preceding claim where the substrate also serves as the underlayer.
Claim 11
Dependent Claim
18 words
Method as claimed in any preceding claim wherein said overlayer is absent in one or more selected region(s).
Claim 12
Dependent Claim
89 words
A magnetoresistive read transducer comprising: a single elongated continuous layer of magnetoresistive magnetic material having end regions separated by a central region and extending in a longitudinal direction; said central region having a soft magnetic state, and said end regions having a high coercivity; and said end regions having a magnetic state aligned substantially along the longitudinal direction whereby the central region of said magnetoresistive read transducer is maintained in a single-domain state due to continuity of said longitudinal magnetic flux between said central region and said end regions.
Claim 13
Dependent Claim
24 words
The magnetoresistive read transducer of Claim 12 comprising: means for biasing said magnetoresistive magnetic material to achieve linearity of response to external magnetic fields.
Claim 14
Dependent Claim
28 words
The magnetoresistive read transducer of Claim 12, wherein said means for biasing said magnetoresistive material comprises a current carrying layer adjacent to said layer of magnetoresistive magnetic material.
Claim 15
Dependent Claim
35 words
The magnetoresistive read transducer of Claim 12 wherein said means for biasing said magnetoresistive material comprises a layer of soft magnetic material separated from said layer of magnetoresistive material by a thin nonmagnetic spacer layer.
Claim 16
Dependent Claim
20 words
A magnetoresistive transducer having a magnetic structure produced by a method as claimed in any of Claims 1 to 11.
References Cited (Backward Citations)
No citation records indexed.
USPTO Annuity & Maintenance Windows
Maintenance schedule is calculated for granted US utility patents.