Patent EP0422806A2 successfully refreshed from Google Patents.
EP0422806A2
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EP
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Magnetoresistive transducer
Assignee: International Business Machines Corp
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Filing: 1990-09-28
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Granted: —
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Expires: 2010-09-28
Abstract
Abstract A magnetoresistive (MR) read transducer having passive end regions (50) separated by a central active region (44) in which an MR layer (42) is formed which extends over substantially only the central active region and in which a hard magnetic layer (46) is formed in each end region. The hard magnetic layers form an abutting junction (48) having electrical and magnetic continuity with the MR layer to produce a longitudinal bias in the MR sensor. The transducer is produced by a method in which the same stencil defines the extent of both the MR layer and the hard magnetic layers so that the abutting junctions are formed easily and reliably.
Inventors
- 👤 Mohamad Towfik Krounbi
- 👤 Otto Voegeli
- 👤 Po-Kang Wang
Bibliographic Details
Application Number
—
Jurisdiction
EP
Data Source
google_patents
Last Synchronized
2026-11-02 20:48
CPC Classifications
G; G11; G11B; G11B5/00; G11B5/127; G11B5/33; G11B5/39; G11B5/3903
Claims Analysis
Total Claims: 20
Claim 1
Independent Claim
109 words
A magnetoresistive read transducer comprising; a magnetoresistive sensor having passive end regions separated by a central active region; a thin film of magnetoresistive conductive layer formed of magnetic material, said magnetoresistive conductive layer extending over substantially only said central active region; and a first and a second thin film of hard magnetic material, each of said thin film of hard magnetic material forming an abutting junction having electrical and magnetic continuity with a respective different end of said magnetoresistive conductive layer, each of said thin film of hard magnetic material extending over substantially only one of said passive end regions to produce a longitudinal bias in said magnetoresistive sensor.
Claim 2
Dependent Claim
109 words
A magnetoresistive read transducer comprising; a magnetoresistive sensor having passive end regions separated by a central active region; a thin film of magnetoresistive conductive layer formed of magnetic material, said magnetoresistive conductive layer extending over substantially only said central active region; and a first and a second thin film of hard magnetic material, each of said thin film of hard magnetic material forming an abutting junction having electrical and magnetic continuity with a respective different end of said magnetoresistive conductive layer, each of said thin film of hard magnetic material extending over substantially only one of said passive end regions to produce a longitudinal bias in said magnetoresistive sensor.
Claim 3
Dependent Claim
17 words
A magnetoresistive read transducer as claimed in Claim 1 wherein said abutting junction comprises two overlapping tapers.
Claim 4
Dependent Claim
19 words
A magnetoresistive read transducer as claimed in Claim 2 wherein said overlapping tapers comprise a substantially continuous curved surface.
Claim 5
Dependent Claim
32 words
A magnetoresistive read transducer as claimed in any of Claims 1, 2 or 3 wherein said abutting junction has a length between 3 and 5 times the thickness of said magnetoresistive layer.
Claim 6
Dependent Claim
31 words
A magnetoresistive read transducer as claimed in any of Claims 1,2,3 or 4 further comprising means for producing a transverse bias in at least a part of said central active region.
Claim 7
Dependent Claim
27 words
A magnetoresistive read transducer as claimed in Claim 5 wherein said means for producing a transverse bias comprises a soft magnetic film spaced from said magnetoresistive layer.
Claim 8
Independent Claim
139 words
A method for making a magnetoresistive read transducer having passive end regions separated by a central active region comprising the steps of: depositing a thin magnetoresistive layer of ferromagnetic material over at least the central active region of said transducer; producing a stencil covering the central active region of said transducer; etching away the part of said magnetoresistive material not covered by said stencil to form the central active region of said transducer; depositing a film of hard magnetic material over regions of said transducer not covered by said stencil to produce the passive end regions of said transducer, said hard magnetic material in said end regions forming an abutting junction with a respective different end of said layer of magnetoresistive material so that a longitudinal bias is produced in each of said passive end regions of said transducer.
Claim 9
Independent Claim
139 words
A method for making a magnetoresistive read transducer having passive end regions separated by a central active region comprising the steps of: depositing a thin magnetoresistive layer of ferromagnetic material over at least the central active region of said transducer; producing a stencil covering the central active region of said transducer; etching away the part of said magnetoresistive material not covered by said stencil to form the central active region of said transducer; depositing a film of hard magnetic material over regions of said transducer not covered by said stencil to produce the passive end regions of said transducer, said hard magnetic material in said end regions forming an abutting junction with a respective different end of said layer of magnetoresistive material so that a longitudinal bias is produced in each of said passive end regions of said transducer.
Claim 10
Dependent Claim
25 words
A method for making a magnetoresistive read transducer as claimed in Claim 7 wherein said etching step comprises the use of a directional etching method.
Claim 11
Dependent Claim
22 words
A method for making a magnetoresistive read transducer as claimed in Claim 8 wherein said directional etching method comprises ion beam milling.
Claim 12
Independent Claim
34 words
A method for making a magnetoresistive read transducer as claimed in any of Claims 8 or 9 wherein said directional etching method is carried out at a non-zero angle of incidence to said transducer.
Claim 13
Dependent Claim
25 words
A method for making a magnetoresistive read transducer as claimed in Claim 10 wherein said angle is within the range of 70 to 80 degrees.
Claim 14
Independent Claim
44 words
A method for making a magnetoresistive read transducer as claimed in any of Claims 10 or 11 wherein said transducer and angle of incidence of the etching beam are rotated relative to each other about the normal to the tranducer during said etching step.
Claim 15
Independent Claim
40 words
A method for making a magnetoresistive read transducer as claimed in any of Claims 7 to 12 wherein said stencil comprises two layers, the layer which is in contact with the magnetoresistive layer being recessed relative to the other layer.
Claim 16
Independent Claim
38 words
A method for making a magnetoresistive read transducer as claimed in in any of Claims 7 to 12 wherein the portion of said stencil closest to the magnetoresistive layer is undercut from the remaining portion of the stencil.
Claim 17
Independent Claim
46 words
A method for making a magnetoresistive read transducer as claimed in any of Claims 13 or 14 wherein the profile of the tapered deposition is determined by the height of the stencil, the size of the undercut and the angle of incidence of the etching beam.
Claim 18
Independent Claim
39 words
A method for making a magnetoresistive read transducer as claimed in any of Claims 7 to 15 additionally comprising the step of depositing means for producing a transverse bias in at least a part of said central active region.
Claim 19
Dependent Claim
31 words
A method for making a magnetoresistive read transducer as claimed in Claim 16 wherein said means for producing a transverse bias comprises a soft magnetic film spaced from said magnetoresistive layer.
Claim 20
Dependent Claim
18 words
A magnetic data storage device having a magnetoresistive read transducer as claimed in of Claims 1 to 6.
References Cited (Backward Citations)
No citation records indexed.
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