Read head with multiple reader stacks

Patent metadata

Field	Value
Publication number	US-9406321-B2
Application number	US-201414192467-A
Country	US
Kind code	B2
Filing date	Feb 27, 2014
Priority date	Feb 27, 2014
Publication date	Aug 2, 2016
Grant date	Aug 2, 2016

Abstract

A read head includes a bottom shield configured as a bottom electrical contact. A bottom reader stack is disposed on and electrically coupled to the bottom shield. A middle electrical contact is electrically coupled to a top layer of the bottom reader stack. A top reader stack is disposed on the bottom reader stack. A bottom layer of the top reader stack electrically coupled to the middle electrical contact. A top shield is configured as a top electrical contact. The top shield is disposed on and electrically coupled to the top reader stack.

First claim

What is claimed is:

1. A read head, comprising:
a bottom shield configured as a bottom electrical contact;
a bottom reader stack disposed on and electrically coupled to the bottom shield and comprising a cap layer;
a top reader stack disposed on the bottom reader stack with no intervening layers between the cap layer of the bottom reader stack and a seed layer of the top reader stack;
a middle electrical contact recessed from a media-facing surface of the read head and abutting an edge of the top reader stack that faces away from the media-facing surface, the middle electrical contact electrically coupled to the cap layer of the bottom reader stack; and
a top shield configured as a top electrical contact, the top shield disposed on and electrically coupled to the top reader stack.

2. The read head of claim 1 , wherein:
the bottom reader stack comprises a bottom seed layer disposed on the bottom shield; and
the top reader stack comprises a top cap layer, wherein the top shield is disposed on the top cap layer, and wherein a selected one of the seed layer of the top reader stack and the bottom seed layer extend further away from a media-reading surface of the read head than another of the seed layer of the top reader stack and the bottom seed layer.

3. The read head of claim 1 , wherein one of the first and second readers comprises a bottom spin valve reader.

4. The read head of claim 3 , both of the first and second readers comprise bottom spin valve readers.

5. The read head of claim 3 , wherein one of the first and second readers comprises a top spin valve reader.

6. The read head of claim 1 , wherein the top and bottom reader stacks are symmetrically aligned about a centerline of the read head.

7. The read head of claim 1 , wherein the top and bottom reader stacks are asymmetrically aligned about a centerline of the read head.

8. The read head of claim 1 , wherein at least one of the top and bottom reader stack is offset from the other of the top and bottom reader stack.

9. The read head of claim 1 , wherein the middle electrical contact is electrically coupled to an edge of the cap layer of the bottom reader stack that faces away from the media-facing surface.

10. The read head of claim 1 , wherein the seed layer of the top reader stack extends further away from the media-facing surface than any layers of the bottom stack.

11. The read head of claim 1 , wherein the middle electrical contact is formed separately from the top reader stack.

12. A read head, comprising:
a bottom shield configured as a bottom electrical contact;
a bottom reader stack disposed on and electrically coupled to the bottom shield;
at least one middle shield disposed on the bottom reader stack and configured as at least one middle electrical contact;
a top reader stack disposed on the at least one middle shield; and
a top shield configured as a top electrical contact, the top shield disposed on and electrically coupled to the top reader stack, at least one of the top and bottom reader stacks are electrically coupled to the at least one middle shield, a selected one of the top and bottom reader stack comprising long seed layers that extend further away from a media-reading surface of the read head than seed layers of the other of the top and bottom reader stack.

13. The read head of claim 12 , wherein both the top and bottom reader stacks are electrically coupled to the at least one middle shield.

14. The read head of claim 13 , wherein the at least one middle shield comprises a synthetic anti-ferromagnet.

15. The read head of claim 12 , wherein the at least one middle shield comprises a lower middle shield electrically coupled to the bottom reader stack and an upper middle shield electrically coupled to the top reader stack, the read head further comprising an electrical isolation layer between the upper and lower middle shields.

16. The read head of claim 15 , wherein:
the at least one middle electrical contact comprises a lower middle electrical contact electrically coupled to the lower middle shield and an upper middle electrical contact electrically coupled to the upper middle shield;
the electrical isolation layer extends between the upper and lower middle electrical contacts.

17. The read head of claim 12 , wherein both of the first and second readers comprises bottom spin valve readers.

18. The read head of claim 17 , wherein both of the first and second readers comprises bottom spin valve readers and another of the first and second readers comprises a top spin valve reader.

19. A read head, comprising:
a bottom shield configured as a bottom electrical contact;
a bottom reader stack disposed on and electrically coupled to the bottom shield;
a first middle electrical contact recessed from a media-facing surface of the read head and electrically coupled to a cap layer of the bottom reader stack;
a middle reader stack, a seed layer of the middle reader stack being disposed on the cap layer of the bottom reader stack with no intervening layers therebetween, the seed layer of the middle reader stack electrically coupled to the first middle electrical contact, an edge of the middle reader stack that faces away from the media-facing surface abutting the first middle electrical contact;
a second middle electrical contact recessed from the media-facing surface electrically coupled to a cap layer of the middle reader stack and;
a top reader stack, seed layer of the top reader stack being disposed on the cap layer of the middle reader stack with no intervening layers therebetween, the seed layer of the top reader stack electrically coupled to the second middle electrical contact, an edge of the top reader stack that faces away from the media-facing surface abutting the second middle electrical contact; and
a top shield configured as a top electrical contact, the top shield disposed on and electrically coupled to a cap layer of the top reader stack.

20. The read head of claim 19 , wherein the bottom layer of the middle reader stack and the bottom layer of the top reader stack extend further away from the media-facing surface than any layers of the bottom stack.

Assignees

• Seagate Technology Llc

Inventors

• Kief Mark Thomas
• Boonstra Thomas Roy
• Sapozhnikov Victor Boris
• Edelman Harry Sam

Classifications

• G11B5/3948

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

• G11B5/3964

  for transducing on a single track · CPC title

• G11B2005/3996

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

• G11B5/3909

  Arrangements using a magnetic tunnel junction · 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