Shorting tolerant tunnel valve head and circuit

Patent metadata

Field	Value
Publication number	US-10229705-B2
Application number	US-201715414506-A
Country	US
Kind code	B2
Filing date	Jan 24, 2017
Priority date	Jan 24, 2017
Publication date	Mar 12, 2019
Grant date	Mar 12, 2019

Abstract

In one general embodiment, an apparatus includes a magnetic head having at least one tunneling magnetoresistance sensor. The resistance of the tunnel barrier of each tunneling magnetoresistance sensor is about 25 ohms or less. In another general embodiment, an apparatus includes a magnetic head having at least one tunneling magnetoresistance sensor. The resistivity of the tunnel barrier of each tunneling magnetoresistance sensor is less than a product of a target resistance of the tunnel barrier and an area of the tunnel barrier. The target resistance is about 25 ohms or less.

First claim

What is claimed is:

1. An apparatus, comprising:
a magnetic head having at least two tunneling magnetoresistance sensors,
wherein a resistance of a tunnel barrier of each of the tunneling magnetoresistance sensors of the magnetic head is about 25 ohms or less,
a drive mechanism for passing a magnetic medium over the magnetic head; and
a controller electrically coupled to the magnetic head,
wherein the controller includes a biasing circuit, wherein the biasing circuit sets a predetermined voltage value drop for the tunnel barrier.

2. An apparatus as recited in claim 1 , wherein the tunneling magnetoresistance sensors are present in the magnetic head in an array.

3. An apparatus as recited in claim 2 , wherein the array is linear.

4. An apparatus as recited in claim 1 , wherein a lower shield of the sensor is formed above a wafer substrate, wherein an insulating layer is positioned between the lower shield and the wafer substrate, wherein an average distance between the lower shield and the wafer substrate is less than about 100 nm.

5. An apparatus as recited in claim 4 , comprising an electrically conductive spacer between the tunnel barrier and at least one of the shields.

6. An apparatus as recited in claim 5 , wherein the electrically conductive spacer comprises iridium.

7. An apparatus as recited in claim 1 , comprising an upper layer above an upper shield of the sensor, wherein an insulating layer is positioned between the upper shield and the upper layer, wherein an average distance between the upper shield and the upper layer is less than about 100 nm.

8. An apparatus as recited in claim 7 , wherein the upper layer has a higher thermal conductivity than the upper shield.

9. An apparatus as recited in claim 8 , wherein the upper layer has a higher hardness than the upper shield.

10. An apparatus as recited in claim 1 , comprising a protective coating on a media facing side of the sensor, wherein at least some layers of the sensor are recessed from a plane of a media bearing surface, wherein an extent of the recession plus a thickness of the protective coating is greater than about 10 nm.

11. An apparatus as recited in claim 1 , wherein a stripe height of the tunnel barrier is at least ⅔ of a track width of the tunnel barrier or greater.

12. An apparatus as recited in claim 1 , wherein the magnetic head is a tape head.

13. An apparatus, comprising:
a magnetic head having at least two tunneling magnetoresistance sensors,
wherein a resistance of a tunnel barrier of each of the tunneling magnetoresistance sensors of the magnetic head is about 25 ohms or less,
wherein the tunneling magnetoresistance sensors are present in the magnetic head in an array,
wherein each sensor is configured to read a unique data track, wherein the sensors are configured to concurrently read the data tracks.

14. An apparatus, comprising:
a magnetic head having at least two tunneling magnetoresistance sensors, wherein a plurality of tunneling magnetoresistance sensors are present in the magnetic head in an array,
wherein a resistivity of a tunnel barrier of each of the tunneling magnetoresistance sensors of the magnetic head is less than a product of a target resistance of the tunnel barrier and an area of the tunnel barrier,
wherein the target resistance is about 25 ohms or less,
wherein each sensor is configured to read a unique data track, wherein the sensors are configured to concurrently read the data tracks.

15. An apparatus as recited in claim 14 , wherein the array is linear.

16. An apparatus as recited in claim 14 , further comprising:
a drive mechanism for passing a magnetic medium over the magnetic head; and
a controller electrically coupled to the magnetic head.

17. An apparatus, comprising:
a magnetic head having at least one tunneling magnetoresistance sensor,
wherein a stripe height of a tunnel barrier of each tunneling magnetoresistance sensor of the magnetic head is greater than a quotient of a resistivity of the tunnel barrier divided by a product of a track width of the tunnel barrier and a target resistance of the tunnel barrier,
wherein the target resistance is about 25 ohms or less.

18. An apparatus as recited in claim 17 , wherein a plurality of tunneling magnetoresistance sensors are present in the magnetic head in an array.

19. An apparatus as recited in claim 18 , wherein the array is linear.

20. An apparatus as recited in claim 18 , wherein each sensor is configured to read a unique data track, wherein the sensors are configured to concurrently read the data tracks.

21. An apparatus as recited in claim 17 , further comprising:
a drive mechanism for passing a magnetic medium over the magnetic head; and
a controller electrically coupled to the magnetic head.

Assignees

• IBM

Inventors

• Biskeborn Robert G
• Czarnecki W Stanley
• Liang Jason
• Lo Calvin S

Classifications

• G11B5/3932

  Magnetic biasing films · CPC title

• G11B5/3909

  Arrangements using a magnetic tunnel junction · CPC title

• G11B5/3948 Primary

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

• G11B5/3958

  the active elements being arranged in a single plane, e.g. "matrix" disposition · CPC title

• G11B5/3951

  the active elements being arranged on several parallel planes · CPC title