Dual reader structure

Patent metadata

Field	Value
Publication number	US-9190078-B2
Application number	US-201314014597-A
Country	US
Kind code	B2
Filing date	Aug 30, 2013
Priority date	Aug 30, 2013
Publication date	Nov 17, 2015
Grant date	Nov 17, 2015

Abstract

Implementations described and claimed herein provide a stacked dual reader with a bottom sensor stack and a top sensor stack wherein the bottom sensor stack and the top sensor stack are mirrored along a down-track direction.

First claim

What is claimed is:

1. An apparatus comprising:
a stacked dual reader with a bottom sensor stack and a top sensor stack, wherein the bottom sensor stack and the top sensor stack are mirrored along a down-track direction, and wherein a mid-shield separates the bottom sensor stack and the top sensor stack; a pre-amplifier circuit comprising a lead connected to the mid-shield, configured to collect current flowing from the mid-shield through the top sensor stack in the presence of an external field opposite a direction of current flowing from the mid-shield through the bottom sensor stack in the presence of the external field.

2. The apparatus of claim 1 wherein the bottom sensor stack is arranged between a bottom SAF shield and a bottom mid-shield with a free layer of the bottom sensor stack being adjacent to the bottom mid-shield and wherein the top sensor stack is arranged between a top SAF shield and a top mid-shield with a free layer of the top sensor stack being adjacent to the top mid-shield.

3. The apparatus of claim 1 wherein a down-track distance between a free layer of the top sensor stack and a free layer of the bottom sensor stack is approximately in the range of 10 nm to 40 nm.

4. The apparatus of claim 1 , wherein the bottom sensor stack is arranged between a bottom shield and the mid-shield and the top sensor stack is arranged between a top shield and an AFM layer of the mid-shield.

5. A dual reader, comprising:
a bottom sensor stack and a top sensor stack separated by at least one mid-shield; a pre-amplifier circuit comprising a first lead connected to the mid-shield, configured to collect current flowing from the mid-shield through the top sensor stack in the presence of an external field opposite a direction of current flowing from the mid-shield through the bottom sensor stack in the presence of the external field.

6. The dual reader of claim 5 , wherein the bottom sensor stack and the top sensor stack are mirrored along a down-track direction.

7. The dual reader of claim 5 , wherein the bottom sensor stack includes an AFM layer in contact with a bottom shield and the top sensor stack includes an AFM layer in contact with a top shield.

8. The dual reader of claim 5 , wherein there is no insulation layer between the bottom sensor stack and the top sensor stack.

9. The dual reader of claim 5 , wherein a down-track distance between a free layer of the top sensor stack and a free layer of the bottom sensor stack is approximately in the range of 10 nm to 40 nm.

10. The dual reader of claim 5 , wherein the pre-amplifier circuit comprises a three-lead pre-amplifier circuit configured to read a signal from the dual reader, wherein the first lead is one of the three leads of the pre-amplifier circuit.

11. The dual reader of claim 10 , wherein a second lead of the three-lead pre-amplifier circuit is connected to a top shield and a third lead of the three-lead pre-amplifier circuit is connected to a bottom shield.

12. The dual reader of claim 5 , wherein the bottom sensor stack is arranged between a bottom shield and the mid-shield and the top sensor stack is arranged between a top shield and an AFM layer of the mid-shield.

13. A storage device comprising:
a magnetic media;
a dual reader including a bottom sensor stack and a top sensor stack, wherein a mid-shield separates the bottom sensor stack and the top sensor stack; a pre-amplifier circuit comprising a first lead connected to the mid-shield, configured to collect current flowing from the mid-shield through the top sensor stack in the presence of an external field opposite a direction of current flowing from the mid-shield through the bottom sensor stack in the presence of the external field.

14. The storage device of claim 13 , wherein the top sensor stack and the bottom sensor stack are mirrored along a down-track direction.

15. The storage device of claim 13 , wherein a polarity of a signal generated by the bottom sensor stack is opposite the polarity of a signal generated by the top sensor stack.

16. The storage device of claim 13 , wherein signals generated by the dual reader are read by three leads of the pre-amplifier circuit, wherein the first lead is one of the three leads of the pre-amplifier circuit.

17. The storage device of claim 16 , wherein a second lead of the three-lead pre-amplifier circuit is connected to a top shield and a third lead of the three-lead pre-amplifier circuit is connected to a bottom shield.

18. The storage device of claim 13 , wherein the bottom sensor stack includes an AFM layer in contact with a bottom shield and the top sensor stack includes an AFM layer in contact with a top shield.

19. The storage device of claim 13 , wherein there is no insulation layer between the bottom sensor stack and the top sensor stack.

20. The storage device of claim 13 , wherein the bottom sensor stack is arranged between a bottom shield and the mid-shield and the top sensor stack is arranged between a top shield and an AFM layer of the mid-shield.

Assignees

• Seagate Technology Llc

Inventors

• Sapozhnikov Victor Boris
• Edelman Harry
• Patwari Mohammed Sharia Ullah

Classifications

• G11B5/4886

  relative to rotating disc · CPC title

• G11B5/3948 Primary

  the sensitive elements being active read-out elements · CPC title

• G11B5/115 Primary

  Shielding devices arranged between heads or windings ({G11B5/265} , G11B5/29 take precedence) · CPC title

• G11B5/3912

  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 title

• G11B5/398

  Specially shaped layers · CPC title