PRESSURE SENSOR DEVICE

• US 20140069200A1
• Filed: 01/24/2013
• Published: 03/13/2014
• Est. Priority Date: 09/10/2012
• Status: Active Grant

• Current Assignee: Kabushiki Kaisha Toshiba (Toshiba Corporation)
• Original Assignee: Kabushiki Kaisha Toshiba (Toshiba Corporation)
• Inventors: Yuasa, Hiromi, Fukuzawa, Hideaki, Fuji, Yoshihiko, Hara, Michiko, Nagata, Tomohiko, Hori, Akio, Higashi, Yoshihiro
• Granted Patent: US 9,618,411 B2
• Time in Patent Office: Days
• US Class Current: 73/725
• CPC Class Codes: G01L 1/125 by using magnetostrictive means magnetostrictive sensors H10N35/101
• CPC Class Codes: G01L 9/0051 using variations in ohmic resistance
• CPC Class Codes: G01L 9/16 by making use of variations in the magnetic properties of material resulting from the application of stress
• CPC Class Codes: H10N 35/101 with mechanical input and electrical output, e.g. generators, sensors

Abstract

A pressure sensor device comprises a support substrate including a thin film area which is bendable by a pressure, a sensor film comprising a first electrode provided on the thin film area, a second electrode provided on the first electrode, a reference layer provided between the first electrode and the second electrode, a free layer provided between the reference layer and the first electrode or between the reference layer and the second electrode, a spacer layer provided between the reference layer and the free layer, a shield provided on a side of the support substrate.

Claims

1. A pressure sensor device comprising:

a support substrate comprising a thin film area bendable by a pressure and a support part fixing the thin film area;

a sensor film comprising a first electrode provided on the thin film area, a second electrode provided on the first electrode, a reference layer provided between the first electrode and the second electrode, a free layer provided between the reference layer and the first electrode or between the reference layer and the second electrode, and a spacer layer provided between the reference layer and the free layer, wherein the magnetization of the free layer is changeable when the thin film area is bent;

a shield provided on a side of the support substrate, the shield comprised of a soft magnetic material.

2. The device of claim 1, wherein the support part is formed so as to surround the thin film area.

3. The device of claim 1, a material of the thin film area is different from a material of the support substrate.

4. The device of claim 1, wherein the first electrode and the second electrode are comprised of a soft magnetic material.

5. The device of claim 1, wherein an absolute value of a magnetostrictive constant of the free layer is larger than an absolute value of a magnetostrictive constant of each of the shield, the first electrode, and the second electrode.

6. The device of claim 1, wherein the shield is comprised of NiFe alloy, NiFeX alloy (X is Cu, Cr, Ta, Rh, Pt, or Nb), CoZrNb alloy, or FeAlSi alloy.

7. The device of claim 1, wherein a thickness of the shield is greater than a distance from a top of the sensor film, when the thin film area is bent, to a top of the support substrate.

8. The device of claim 1, wherein the free layer exists in a range from a top of the support substrate to a top of the shield.

9. The device of claim 1, wherein the shield surrounds a part of the sensor film and includes at least one gap when viewed from a top of the support substrate.

10. The device of claim 1, wherein a plurality of the shields are provided.

11. The device of claim 1, further comprising a pair of hard biases provided on the thin film area, sandwiching the sensor film.

12. The device of claim 1, further comprising an antiferromagnetic layer provided between the reference layer and the first electrode.

13. The device of claim 1, further comprising an antiferromagnetic layer provided between the reference layer and the second electrode.

14. The device of claim 1, wherein the reference layer is formed of a first reference and a second reference layer.

15. The device of claim 14, further comprising an antiparallel coupled layer provided between the first reference layer and the second reference layer.

16. The device of claim 1, wherein the shield is circular and surrounds a portion of the thin film area.

17. The device of claim 16, wherein the shield includes a plurality of circular shields.

18. The device of claim 1, wherein the shield is a polygon surrounding a portion of the thin film area.

19. The device of claim 1, wherein a thickness of the support part is larger than a thickness of the thin film area.