IP Library Granted Patent US 7,355,821
Granted Patent B2
US 7,355,821 · App. 11/052,814 · Granted Apr 8, 2008

Magneto resistive (MR) head

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Quick Facts
Patent No.
US 7,355,821
App. No.
11/052,814
Granted
Apr 8, 2008
Kind
B2
Abstract

Disclosed is an MR head in which the MR element resists damage due to ESD. A magneto resistive head to be in contact with a running magnetic tape includes a substrate, an insulating layer, a magneto resistive element located in the insulating layer, at least one shield layer for shielding the magneto resistive element from magnetic fields, and a conductive layer that has a conductive surface being in contact with the magnetic tape and that is electrically connected to the substrate. In this head, static electricity accumulated on the magnetic tap is discharged through the conductive layer and the substrate.

Claims (45)

1. A magneto resistive head to be in contact with a running magnetic tape, comprising:

a substrate;

an insulating layer;

a magneto resistive element located in the insulating layer;

at least one shield layer for shielding the magneto resistive element from magnetic fields; and

a conductive layer having a conductive surface being in contact with the magnetic tape, the conductive layer being electrically connected to the substrate;

wherein static electricity accumulated on the magnetic tap is discharged through the conductive layer and the substrate.

2. The magneto resistive head according to claim 1 , further comprising a protective layer for protecting the conductive layer.

3. The magneto resistive head according to claim 1 ,

wherein the conductive layer covers at least one surface of the magneto resistive element, which faces the magnetic tape.

4. The magneto resistive head according to claim 1 ,

wherein the conductive layer covers whole surfaces of the substrate and the insulating layer, which face the magnetic tape.

5. The magneto resistive head according to claim 1 ,

wherein the conductive layer has a carbon content of at least 50%.

6. The magneto resistive head according to claim 1 ,

wherein the conductive layer has resistivity ranging from 1 Ωcm to 10 6 Ωcm.

7. The magneto resistive head according to claim 1 ,

wherein the conductive layer has a thickness ranging from 1 nm to 20 nm.

8. The magneto resistive head according to claim 2 ,

wherein the protective layer has a thickness ranging from 2 nm to 50 nm.

9. The magneto resistive head according to claim 1 ,

wherein the shield layer is made of at least one of a Fe—Si—Al alloy, a Ni—Fe alloy and a Ni—Zn alloy.

10. A magneto resistive head to be in contact with a running magnetic tape, comprising:

a substrate;

an insulating layer;

a magneto resistive element located in the insulating layer;

at least one shield layer for shielding the magneto resistive element from magnetic fields; and

at least one conductive region formed in the insulating layer and between the shield layer and the substrate, the conductive region having a surface which is exposed from the insulating layer and which is in contact with the magnetic tape, the conductive region being electrically connected to the substrate,

wherein static electricity accumulated on the magnetic tape is discharged through the conductive region and the substrate.

11. The magneto resistive head according to claim 10 , further comprising a conductive boundary layer formed between the conductive region in the insulating layer and the substrate.

12. The magneto resistive head according to claim 10 , further comprising a conductive layer being in contact with the magnetic tape, the conductive layer being electrically connected to the substrate.

13. The magneto resistive head according to claim 10 , further comprising a protective layer for protection from the magnetic tape.

14. The magneto resistive head according to claim 12 , further comprising a protective layer for protecting the conductive layer.

15. The magneto resistive head according to claim 11 ,

wherein the boundary layer has a carbon content of at least 50%.

16. The magneto resistive head according to claim 11 ,

wherein the boundary layer has resistivity ranging from 1 Ωcm to 10 6 Ωcm.

17. The magneto resistive head according to claim 11 ,

wherein the boundary layer has a thickness ranging from 1 nm to 20 nm.

18. The magneto resistive head according to claim 12 ,

wherein the conductive layer has resistivity ranging from 1 Ωcm to 10 6 Ωcm.

19. The magneto resistive head according to claim 13 ,

wherein the protective layer has a thickness ranging from 2 nm to 50 nm.

20. The magneto resistive head according to claim 14 ,

wherein the protective layer has a thickness ranging from 2 nm to 50 nm.

Assignments (1)
ASSIGNMENT OF ASSIGNOR'S INTEREST Recorded Feb 15, 2007
From: FUJIFILM HOLDINGS CORPORATION (FORMERLY FUJI PHOTO FILM CO., LTD.)
To: FUJIFILM CORPORATION
Reel/Frame 018904/0001 →