Data Reader with Front Shield Coupling Structure

• US 20170033278A1
• Filed: 07/27/2015
• Published: 02/02/2017
• Est. Priority Date: 07/27/2015
• Status: Active Grant

• Current Assignee: Seagate Technology LLC (Seagate Technology Holdings Plc)
• Original Assignee: Seagate Technology LLC (Seagate Technology Holdings Plc)
• Inventors: Lapicki, Adam A., Hassan, Sameh, Du, YuQing, Kief, Mark T., Ormston, Marcus W.
• Granted Patent: US 9,634,242 B2
• Time in Patent Office: Days
• US Class Current: 1/1
• CPC Class Codes: G01R 33/0011 comprising means, e.g. flux concentrators, flux guides, for guiding or concentrating the magnetic flux, e.g. to the magnetic sensor
• CPC Class Codes: G01R 33/0017 Means for compensating offset magnetic fields or the magnetic flux to be measured; Means for generating calibration magnetic fields
• CPC Class Codes: G01R 33/0076 Protection, e.g. with housings against stray fields
• CPC Class Codes: G01R 33/093 using multilayer structures, e.g. giant magnetoresistance sensors thin magnetic films H01F10/00
• CPC Class Codes: G11B 5/3912 Arrangements in which the active read-out elements are transducing in association with active magnetic shields, e.g. magnetically coupled shields G11B5/3916 takes precedence
• CPC Class Codes: G11B 5/3932 Magnetic biasing films
• CPC Class Codes: G11B 5/398 Specially shaped layers
• CPC Class Codes: H10N 50/10 Magnetoresistive devices

Abstract

A data reader may consist of at least a magnetoresistive stack positioned on an air bearing surface. A portion of the magnetoresistive stack may be set to a first fixed magnetization by a pinning structure separated from the air bearing surface by a front shield that is set to a second fixed magnetization by a biasing structure. The front shield may be separated from the biasing structure by a coupling structure.

Claims

1. An apparatus comprising a magnetoresistive stack positioned on an air bearing surface (ABS), a portion of the magnetoresistive stack set to a first fixed magnetization by a pinning structure separated from the ABS by a front shield, the front shield set to a second fixed magnetization by a biasing structure, the front shield separated from the biasing structure by a coupling structure.

2. The apparatus of claim 1, wherein the magnetoresistive stack comprises a magnetically free structure having a first stripe height as measured perpendicular to the ABS and a magnetically fixed structure set to the first fixed magnetization and having a second stripe height from the ABS, the first stripe height being smaller than the second stripe height.

3. The apparatus of claim 1, wherein the pinning structure is separated from the front shield by a non-ferromagnetic transition metal layer.

4. The apparatus of claim 1, wherein the pinning structure has a front surface proximal the ABS, the front surface canted at a non-normal angle with respect to the ABS.

5. The apparatus of claim 1, wherein the coupling structure comprises CoFe.

6. The apparatus of claim 1, wherein the coupling structure comprises NiFe.

7. The apparatus of claim 1, wherein the coupling structure continuously extends from the ABS to separate the front shield from the biasing structure and the pinning structure.

8. The apparatus of claim 1, wherein the second fixed magnetization is orthogonal to the first fixed magnetization.

9. The apparatus of claim 1, wherein the coupling structure antiferromagnetically couples the front shield to the biasing structure.

10. The apparatus of claim 1, wherein the coupling structure ferromagnetically couples the front shield to the biasing structure.

11. An apparatus comprising:

a magnetoresistive stack positioned on an air bearing surface (ABS);

a first pinning structure contacting the magnetoresistive stack to set a portion of the magnetoresistive stack to a first fixed magnetization; and

a front shield separating the first pinning structure from the ABS, the front shield set to a second fixed magnetization by a biasing structure, the front shield separated from the biasing structure by a first coupling structure comprising first and second coupling sub-layers.

12. The apparatus of claim 11, wherein a second pinning structure of the biasing structure sets the second fixed magnetization.

13. The apparatus of claim 12, wherein the second pinning structure comprises a synthetic antiferromagnet (SAF).

14. The apparatus of claim 13, wherein a second coupling structure is disposed between first and second ferromagnetic layers of the SAF, the second coupling structure comprising a non-magnetic material disposed between first and second magnetic materials.

15. The apparatus of claim 12, wherein the second pinning structure is disposed between the coupling structure and a shield layer.

16. The apparatus of claim 11, wherein the first coupling sub-layer is non-magnetic and the second coupling sub-layer is magnetic.

17. The apparatus of claim 11, wherein the first coupling sub-layer is a transition metal material and is disposed between the second coupling sub-layer and a third coupling sub-layer, the second and third coupling sub-layers each being a common magnetic material.

18. The apparatus of claim 17, wherein the common magnetic material comprises CoFe.

19. A method comprising:

positioning a magnetoresistive stack on an air bearing surface (ABS);

setting a first fixed magnetization in a portion of the magnetoresistive stack with a pinning structure contacting the magnetoresistive stack; and

setting a second fixed magnetization in a front shield with a biasing structure; and

integrating the biasing structure with both the front shield and the magnetoresistive stack, the front shield separating the pinning structure from the ABS, the front shield separated from the biasing structure by a coupling structure.

20. The method of claim 19, wherein the first and second fixed magnetizations are orthogonal after an annealing operation.