Method for AFC shields for multiple sensor magnetic transducers and magnetic transducers having multiple sensors and AFC shields

Patent metadata

Field	Value
Publication number	US-10115419-B2
Application number	US-201715672857-A
Country	US
Kind code	B2
Filing date	Aug 9, 2017
Priority date	Mar 24, 2015
Publication date	Oct 30, 2018
Grant date	Oct 30, 2018

Abstract

A method and system provide a magnetic transducer having an air-bearing surface (ABS). The method includes providing a first shield, a first read sensor, an antiferromagnetically coupled (AFC) shield that includes an antiferromagnet, a second read sensor and a second shield. The read sensors are between the first and second shields. The AFC shield is between the read sensors. An optional anneal for the first shield is in a magnetic field at a first angle from the ABS. Anneals for the first and second read sensors are in magnetic fields in desired first and second read sensor bias directions. The AFC shield anneal is in a magnetic field at a third angle from the ABS. The second shield anneal is in a magnetic field at a fifth angle from the ABS. The fifth angle is selected based on a thickness and a desired AFC shield bias direction for the antiferromagnet.

First claim

What is claimed is:

1. A magnetic recording device comprising:
a magnetic read transducer comprising:
a first read sensor, a second read sensor, and a third read sensor, wherein the first read sensor, the second read sensor, and the third read sensor are positioned in a down track direction with the second read sensor between the first read sensor and the third read sensor, and wherein the first read sensor, the second read sensor, and the third read sensor are offset from one another in a cross track direction, the down track direction being in a plane that is parallel to an air bearing surface of the magnetic read transducer and the cross track direction being in a plane that is perpendicular to the air bearing surface;
a first middle shield between the first read sensor and the second read sensor, wherein the first middle shield comprises a first top middle shield and a first bottom middle shield separated by a first insulator; and
a second middle shield between the second read sensor and the third read sensor, wherein the second middle shield comprises a second top middle shield and a second bottom middle shield separated by a second insulator,
wherein the first top middle shield comprises a first antiferromagnetic layer and the first bottom middle shield comprises a second antiferromagnetic layer; and
wherein the first antiferromagnetic layer is separated from the second antiferromagnetic layer by the first insulator; and
wherein the first top middle shield further comprises a first plurality of layers between the first antiferromagnetic layer and the first read sensor and the first bottom middle shield further comprises a second plurality of layers between the second antiferromagnetic layer and the second read sensor.

2. The magnetic recording device of claim 1 , wherein the magnetic read transducer is fabricated on a slider of the magnetic recording device.

3. The magnetic recording device of claim 1 , further comprising a bottom shield adjacent to the first read sensor, wherein the first read sensor is between the bottom shield and the first middle shield.

4. The magnetic recording device of claim 1 , further comprising a top shield adjacent to the third read sensor, wherein the third read sensor is between the top shield and the second middle shield, and wherein the top shield comprises a first magnetic layer, a second magnetic layer, a nonmagnetic layer separating the first magnetic layer and the second magnetic layer, and a third antiferromagnetic layer separated from the third read sensor by the first magnetic layer, the second magnetic layer, and the nonmagnetic layer.

5. The magnetic recording device of claim 1 , wherein the first plurality of layers of the first top middle shield comprises a first magnetic layer and a second magnetic layer separated by a nonmagnetic layer.

6. The magnetic recording device of claim 5 , wherein the first bottom middle shield is an antiferromagnetic shield, and wherein the second plurality of layers comprises a third magnetic layer and a fourth magnetic layer separated by an additional nonmagnetic layer.

7. The magnetic recording device of claim 1 , wherein the second top middle shield comprises a first magnetic layer and a second magnetic layer separated by a nonmagnetic layer, and a third antiferromagnetic layer separated from the second read sensor by the first magnetic layer, the second magnetic layer, and the nonmagnetic layer.

8. The magnetic recording device of claim 1 , wherein the second bottom middle shield is a monolithic shield.

9. The magnetic recording device of claim 1 , wherein the second bottom middle shield is an antiferromagnetic shield comprising a first magnetic layer and a second magnetic layer separated by a nonmagnetic layer, and an antiferromagnetic layer separated from the third read sensor by the first magnetic layer, the second magnetic layer, and the nonmagnetic layer.

10. The magnetic recording device of claim 1 , wherein the first middle shield is configured to be magnetically biased at an angle of least zero degrees and not more than fifty-five degrees from the air bearing surface.

11. The magnetic recording device of claim 1 , wherein each of the first read sensor, the second read sensor, and the third sensor are flanked on either side in the cross track direction by a magnetic bias structure.

12. A magnetic read transducer comprising:
a first read sensor;
a second read sensor positioned in a down track direction from the first read sensor and offset from the first read sensor in a cross track direction, wherein the down track direction is in a plane that is parallel to an air bearing surface of the magnetic read transducer and the cross track direction is in a plane that is perpendicular to the air bearing surface;
a top middle shield comprising a first magnetic layer, a second magnetic layer, a nonmagnetic layer separating the first magnetic layer and the second magnetic layer, and an antiferromagnetic layer, wherein the first magnetic layer is between the first read sensor and the nonmagnetic layer and the antiferromagnetic layer is between the second magnetic layer and the second read sensor;
a bottom middle shield between the antiferromagnetic layer and the second read sensor, the bottom middle shield comprising a first additional magnetic layer and an additional antiferromagnetic layer; and
an insulator layer between the top middle shield and the bottom middle shield,
wherein the antiferromagnetic layer is between the insulator layer and the second magnetic layer, and
wherein the additional antiferromagnetic layer is between the insulator layer and the first additional magnetic layer.

13. The magnetic read transducer of claim 12 , wherein the first magnetic layer comprises NiFe layers separated by a CoFeB insertion layer.

14. The magnetic read transducer of claim 12 , wherein the antiferromagnetic layer has a thickness of no more than one hundred and sixty Angstroms.

15. The magnetic read transducer of claim 12 , wherein the bottom middle shield further comprises a second additional magnetic layer and an additional nonmagnetic layer separating the first additional magnetic layer and the second additional magnetic layer.

16. A magnetic read transducer comprising:
a first read sensor;
a second read sensor positioned in a down track direction from the first read sensor and offset from the first read sensor in a cross track direction, wherein the down track direction is in a plane that is parallel to an air bearing surface of the magnetic read transducer and the cross track direction is in a plane that is perpendicular to the air bearing surface;
a top middle shield comprising a first magnetic layer, a second magnetic layer, a nonmagnetic layer separating the first magnetic layer and the second magnetic layer, and an antiferromagnetic layer, wherein the first magnetic layer is between the first read sensor and the nonmagnetic layer and the antiferromagnetic layer is between the second magnetic layer and the second read sensor;
a bottom middle shield between the antiferromagnetic layer and the second read sensor the bottom middle shield comprising a first additional magnetic layer and an additional antiferromagnetic layer;
an insulator layer between the top middle shield and the bottom middle shield, wherein the additional antiferromagnetic layer is between the insulator layer and the first additional magnetic layer, and wherein the antiferromagnetic layer is between the insulator layer and the second magnetic layer; and
a top shield adjacent to the second read sensor in the down track direction, wherein the

Assignees

• Western Digital Fremont Llc

Inventors

• Xiao Rongfu
• He Shihai
• Mauri Daniele
• Mao Ming
• Li Shaoping

Classifications

• G11B5/3909

  Arrangements using a magnetic tunnel junction · CPC title

• G11B2005/3996

  large or giant magnetoresistive effects [GMR], e.g. as generated in spin-valve [SV] devices · CPC title

• G11B5/4886

  relative to rotating disc · CPC title

• G11B5/3912 Primary

  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 title

• G11B5/397

  with a plurality of independent magnetoresistive active read-out elements for respectively transducing from selected components · CPC title