MAGNETIC SENSOR WITH SHUNTING LAYERS AND MANUFACTURING METHOD THEREOF

• US 20130113473A1
• Filed: 11/04/2011
• Published: 05/09/2013
• Est. Priority Date: 11/04/2011
• Status: Abandoned Application

• Current Assignee: SAE Magnetics Limited (TDK Corporation)
• Original Assignee: SAE Magnetics Limited (TDK Corporation)
• Inventors: XIONG, Wei
• Application Number:
  US13/289,539
• Publication Number:
  US 20130113473A1
• Time in Patent Office: Days
• US Class Current: 324/244
• CPC Class Codes: G01R 33/0023 Electronic aspects, e.g. circuits for stimulation, evaluation, control; Treating the measured signals; calibration G01R33/0017 takes precedence
• CPC Class Codes: G01R 33/007 Environmental aspects, e.g. temperature variations, radiation, stray fields G01R33/025 takes precedence
• CPC Class Codes: H05K 1/16 incorporating printed electric components, e.g. printed resistor, capacitor, inductor
• CPC Class Codes: H05K 2201/083 Magnetic materials
• CPC Class Codes: Y10T 29/49155 Manufacturing circuit on or in base

Abstract

The present invention directs a magnetic sensor with shunting layers, and the magnetic sensor includes a magnetic sensor bar which having an integral structure; and a plurality of shunting layers whose resistivity is lower than the magnetic sensor bar, respectively forming on the magnetic sensor bar in length direction without any physical separation therebetween, with spaces between every two adjacent shunting layers; and two electrode pads respectively forming on two ends of the magnetic sensor bar. The present invention also provides manufacturing method of the magnetic sensor.

Claims

1. A magnetic sensor with shunting layers, comprising:

a magnetic sensor bar having an integral structure;

a plurality of shunting layers, whose resistivity is lower than the magnetic sensor bar, respectively forming on the magnetic sensor bar in length direction without any physical separation therebetween, and with spaces between every two adjacent shunting layers; and

two electrode pads respectively forming on two ends of the magnetic sensor bar.

2. The magnetic sensor according to claim 1, wherein the ratio of the width of magnetic sensor bar to the space between any two adjacent shunting layers is within the range of 0.8-1.2.

3. The magnetic sensor according to claim 1, wherein the width of magnetic sensor bar is identical to the space between any two adjacent shunting layers.

4. The magnetic sensor according to claim 1, wherein the shunting layer is a ring enclosing the magnetic sensor bar perpendicular to its length direction.

5. The magnetic sensor according to claim 1, wherein the shunting layer has a shape of square, rectangular or oval to laminate on the magnetic sensor bar.

6. The magnetic sensor according to claim 1, wherein the material of the shunting layer is composed of gold, copper or silver.

7. The magnetic sensor according to claim 1, wherein the magnetic sensor bar is Anisotropic Magneto Resistance, Giant Magneto Resistance or Tunneling Magneto Resistance.

8. The magnetic sensor according to claim 1, wherein the magnetic sensor further comprises a plurality of seedlayers correspondingly sandwiched between the shunting layers and the magnetic sensor bar, so as to achieve good adhesion therebetween.

9. The magnetic sensor according to claim 8, wherein the seedlayer is composed of chromium, titanium or tantalum.

10. The magnetic sensor according to claim 1, wherein the magnetic sensor further comprises an undercoat layer composed of insulating material on which the magnetic sensor bar formed, and a substrate with the undercoat layer formed thereon.

11. The magnetic sensor according to claim 10, wherein the undercoat layer is consisted of alumina or silicon oxide, and the substrate is consisted of silicon, magnesium oxide, sapphire, AlTiC or glass.

12. The magnetic sensor according to claim 1, wherein the magnetic sensor is covered with a protection layer, which is composed of alumina, silicon oxide, ink or polyimide.

13. A manufacturing method of magnetic sensor, comprising:

providing a substrate;

depositing a magnetic sensor film on the substrate, and etching the magnetic sensor film into a plurality of magnetic sensor bars, each of which has an integral structure;

depositing a shunting film on the magnetic sensor bar without any physical separation therebetween, and patterning the shunting film into a plurality of shunting layers, whose resistivity is lower than the magnetic sensor bar, formed in length direction of the magnetic sensor, with spaces between every two adjacent shunting layers; and

depositing two electrode pads respectively on two ends of the magnetic sensor bar.

14. The manufacturing method according to claim 13, wherein the ratio of the width of magnetic sensor bar to the space between any two adjacent shunting layers is within the range of 0.8-1.2.

15. The manufacturing method according to claim 13, wherein the width of magnetic sensor bar is identical to the space between any two adjacent shunting layers.

16. The manufacturing method according to claim 13, wherein etching the magnetic sensor film is carried out by dry or wet etching.

17. The manufacturing method according to claim 13, wherein patterning the shunting film is carried out by dry or wet etching the shunting film with photo mask.

18. The manufacturing method according to claim 13, wherein the shunting layer is a ring enclosing the magnetic sensor bar perpendicular to its length direction.

19. The manufacturing method according to claim 13, wherein the shunting layer has a shape of square, rectangular or oval to laminate on the magnetic sensor bar.

20. The manufacturing method according to claim 13, wherein the material of the shunting layer is composed of gold, copper or silver.

21. The manufacturing method according to claim 13, wherein the magnetic sensor bar is Anisotropic Magneto Resistance, Giant Magneto Resistance, or Tunneling Magneto Resistance.

22. The manufacturing method according to claim 13, wherein the magnetic sensor further comprises a plurality of seedlayers correspondingly sandwiched between the shunting layers and the magnetic sensor bar, so as to achieve good adhesion therebetween.

23. The manufacturing method according to claim 22, wherein the seedlayer is composed of chromium, titanium or tantalum.

24. The manufacturing method according to claim 13, wherein the manufacturing method further comprises a step of depositing an undercoat layer composed of insulating material on the substrate, with the magnetic sensor film laminated thereon.

25. The manufacturing method according to claim 24, wherein the undercoat layer is consisted of alumina or silicon oxide, and the substrate is consisted of silicon, magnesium oxide, sapphire, AlTiC or glass.

26. The manufacturing method according to claim 13, wherein the manufacturing method further comprises a step of covering the magnetic sensor with a protection layer, which is composed of alumina, silicon oxide, ink or polyimide.

27. A manufacturing method of magnetic sensor, comprising:

providing a substrate;

depositing a magnetic sensor film on the substrate, and etching the magnetic sensor film into a plurality of magnetic sensor bars, each of which has an integral structure;

arranging a photo mask directly on the magnetic sensor bar with a plurality of specific areas of the photo mask exposing the magnetic sensor bar, then depositing a shunting film onto and cover the whole the photo mask, whereby a plurality of shunting layers are formed on the magnetic sensor bar without any physical separation therebetween via said specific areas of the photo mask, whose resistivity is lower than the magnetic sensor bar, formed in length direction of the magnetic sensor, with spaces between every two adjacent shunting layers; and

depositing two electrode pads respectively on two ends of the magnetic sensor bar.

28. The manufacturing method according to claim 27, wherein the ratio of the width of magnetic sensor bar to the space between any two adjacent shunting layers is within the range of 0.8-1.2.

29. The manufacturing method according to claim 27, wherein the width of magnetic sensor bar is identical to the space between any two adjacent shunting layers.