Magnetic sensor integrated circuit device and method

• US 8,106,654 B2
• Filed: 05/27/2008
• Issued: 01/31/2012
• Est. Priority Date: 05/27/2008
• Status: Active Grant

• Current Assignee: Infineon Technologies AG
• Original Assignee: Infineon Technologies AG
• Inventors: Theuss, Horst, Wietschorke, Helmut
• Primary Examiner(s): Phan, Huy Q
• Assistant Examiner(s): CHAN, EMILY Y
• Application Number:
  US12/127,510
• Publication Number:
  US 20090295381A1
• Time in Patent Office: 1,344 Days
• Field of Search: 324/252, 32420711-20726, 338/32.R, 360/313
• US Class Current: 324/252
• CPC Class Codes: G01R 33/0005 Geometrical arrangement of magnetic sensor elements; Apparatus combining different magnetic sensor types G01R33/0206 takes precedence
• CPC Class Codes: G01R 33/09 Magnetoresistive devices

Abstract

An sensor includes a substrate with a magnetic field sensor mounted on the substrate. The magnetic field sensor has a first surface defining a plane. A magnetic flux conducting member has a second surface that is not parallel to the first surface. A non-magnetic member is situated between the magnetic field sensor and the magnetic flux conducting member.

Claims

1. A sensor, comprising:

a substrate;

a magnetic field sensor mounted to the substrate, the magnetic field sensor having a first surface defining a plane;

a magnetic flux conducting member having a second surface that is not parallel to the first surface;

a non-magnetic member situated between the magnetic field sensor and the magnetic flux conducting member;

wherein the first surface and the second surface define a cavity, and wherein the non-magnetic member is situated in the cavity.

2. The sensor of claim 1, wherein the non-magnetic member has a third surface that is complementary to the second surface.

3. The sensor of claim 1, wherein the magnetic field sensor is a GMR sensor.

4. The sensor of claim 1, wherein the magnetic field sensor and the magnetic flux conducting member are situated on one side of the substrate.

5. The sensor of claim 1, further comprising a mold compound encapsulating the magnetic field sensor, the magnetic flux conducting member, and the non-magnetic member.

6. The sensor of claim 5, wherein the non-magnetic member is formed from the mold compound.

7. The sensor of claim 1, wherein the non-magnetic member is made of a polymer.

8. The sensor of claim 5, wherein a portion of the magnetic flux conducting member extends from the mold compound.

9. The sensor of claim 1, wherein the second surface is non-planar.

10. The sensor of claim 1, wherein the second surface is generally V-shaped.

11. The sensor of claim 1, further comprising a biasing magnet situated proximate the magnetic flux conducting member.

12. The sensor of claim 1, wherein the magnetic field sensor includes first and second magnetic field sensors, each having a first surface defining a plane, and wherein the magnetic flux conducting member includes first and second flux conducting members.

13. The sensor of claim 1, wherein the non-magnetic member is situated between the first surface and the second surface, and the non-magnetic member contacts both the first and second surfaces.

14. The sensor of claim 13, wherein the first surface is a sensing surface of the sensor.

15. A method of making a magnetic sensor system, comprising:

providing a semiconductor die having a sensor surface with a first surface defining a plane;

mounting the semiconductor die to a substrate;

situating a magnetic flux conducting member adjacent the semiconductor die, the magnetic flux conducting member having a second surface that is not parallel to the plane; and

situating a non-magnetic member between the sensor surface and the magnetic flux conducting member, the non-magnetic member having a third surface that is complementary to the second surface;

wherein the second surface creates a cavity, and wherein the non-magnetic member is formed by filling the cavity with a non-magnetic material.

16. The method of claim 15, wherein the non-magnetic member is formed on the sensor surface, and the magnetic flux conducting member is formed over the non-magnetic member.

17. The method of claim 15, wherein the non-magnetic member is formed on the sensor surface.

18. The method of claim 17, wherein forming the non-magnetic member includes a photolithography process.

19. The method of claim 15, wherein the semiconductor die and the magnetic flux conducting member are on opposite sides of the substrate.

20. The method of claim 15, further comprising encapsulating the magnetic sensor system in a mold compound.

21. The method of claim 20, wherein encapsulating the magnetic sensor system includes leaving a portion of the magnetic flux conducting member extending from the mold compound.

22. The method of claim 15, wherein:

the semiconductor die has first and second sensor surfaces; and

first and second magnetic flux conducting members are situated adjacent the first and second sensor surfaces, respectively.