Magnetic-field sensor

• US 8,773,124 B2
• Filed: 05/30/2008
• Issued: 07/08/2014
• Est. Priority Date: 05/30/2007
• Status: Expired due to Fees

• Current Assignee: Infineon Technologies AG
• Original Assignee: Infineon Technologies AG
• Inventors: Ausserlechner, Udo
• Primary Examiner(s): Assouad, Patrick
• Assistant Examiner(s): BROWN, LAMARR A
• Application Number:
  US12/130,678
• Publication Number:
  US 20090322325A1
• Time in Patent Office: 2,230 Days
• Field of Search: 324/200, 324/207.13, 324/207.2, 324/207.21, 324/232, 324/251, 324/260, 324/207.23, 324/207.24, 324/207.25, 324/173, 324/174, 324/178, 324/179, 735/143.9, 384/448
• US Class Current: 324/252
• CPC Class Codes: G01D 5/145 influenced by the relative movement between the Hall device and magnetic fields see G01R33/06
• CPC Class Codes: G01R 3/00 Apparatus or processes specially adapted for the manufacture or maintenance of measuring instruments , e.g. of probe tips
• CPC Class Codes: G01R 33/02 Measuring direction or magnitude of magnetic fields or magnetic flux G01R33/20 takes precedence
• CPC Class Codes: G01R 33/09 Magnetoresistive devices
• CPC Class Codes: Y10T 29/49002 Electrical device making

Abstract

An embodiment of a magnetic-field sensor includes a magnetic-field sensor arrangement and a magnetic body which has, for example, a non-convex cross-sectional area with regard to a cross-sectional plane running through the magnetic body, the magnetic body having an inhomogeneous magnetization.

Claims

1. A magnetic-field sensor comprising:

a magnetic-field sensor arrangement comprising a first magnetic-field sensor element and a second magnetic-field sensor element in a sensor plane;

a first magnetic body comprising a first magnetization direction; and

a second magnetic body comprising a second magnetization direction,

wherein the first and second magnetization directions differ from each other wherein the first magnetization direction forms a first angle with a symmetry line, the symmetry line being perpendicular to the sensor plane, wherein the second magnetization direction forms a second angle with the symmetry line, and wherein the first and second angles differ by less than 5°

in magnitude.

2. The magnetic-field sensor as claimed in claim 1, wherein the first and second magnetic bodies are arranged such that due to a superposition of a first magnetic field caused by the first magnetic body and of a second magnetic field caused by the second magnetic body, compensation of components of the first and second magnetic fields occurs which is at least partly mutual.

3. The magnetic-field sensor as claimed in claim 1, wherein the first magnetic body comprises a magnetization with regard to the first magnetization direction in a volume of at least 50% of a volume of the first magnetic body, and wherein the second magnetic body comprises a magnetization in the direction of the second magnetization direction in a volume of at least 50% of a volume of the second magnetic body.

4. The magnetic-field sensor as claimed in claim 3, wherein the first magnetic body and the second magnetic body comprise the magnetizations with regard to the first and second magnetization directions, respectively, in a volume of at least 90% of the volumes of the first magnetic body and of the second magnetic body, respectively.

5. The magnetic-field sensor as claimed in claim 1, wherein the first magnetic body and the second magnetic body are arranged in a mirror-image manner with respect to the symmetry line.

6. The magnetic-field sensor as claimed in claim 1, wherein the first and second magnetization direction form an angle of less than 170°

between them.

7. The magnetic-field sensor as claimed in claim 1, wherein a maximum deviation of a magnitude of a magnetization of the first magnetic body and a maximum deviation of a magnitude of a magnetization of the second magnetic body are smaller than or equal to 20% of a maximum magnitude of the magnetizations of the first magnetic body and of the second magnetic body.

8. The magnetic-field sensor as claimed in claim 1, wherein the magnetic-field sensor arrangement comprises first and second magnetic-field sensor elements, wherein the first magnetic-field sensor element is arranged, with respect to the first magnetic body and the second magnetic body, such that the first magnetic-field sensor element is exposed, with respect to a predetermined spatial direction, to a magnetic flux density within a first flux density range, and wherein the second magnetic-field sensor element is arranged, with respect to the first magnetic body and the second magnetic body, such that the second magnetic-field sensor element is exposed, with respect to the predetermined spatial direction, to a magnetic flux density within a second flux density range.

9. The magnetic-field sensor as claimed in claim 8, wherein the first and second magnetic-field sensor elements are magneto-resistive sensor elements.

10. The magnetic-field sensor as claimed in claim 8, wherein the magnetic-field sensor arrangement comprises a substrate comprising the first and second magnetic-field sensor elements arranged thereon, a symmetry line, with regard to which the first magnetic body and the second magnetic body are symmetrically arranged, intersecting a main surface of the substrate at an angle ranging from 75°

to 105°

.

11. The magnetic-field sensor as claimed in claim 8, wherein the magnetic-field sensor arrangement comprises a first magnetic-field sensor element and a second magnetic-field sensor element, the first magnetic-field sensor element being arranged, with respect to the first and second magnetic bodies, such that the first magnetic-field sensor element is exposed, with regard to a predetermined spatial direction, to a magnetic flux density which is caused by the magnetic body and is within a first flux density range, and wherein the second magnetic-field sensor element is arranged, with respect to the first and second magnetic bodies, such that the second magnetic-field sensor element is exposed, with regard to the predetermined spatial direction, to a magnetic flux density which is caused by the magnetic body and is within a second flux density range.

12. The magnetic-field sensor as claimed in claim 8, wherein the first and second magnetic-field sensor elements are arranged on a substrate, and wherein the predetermined spatial direction is parallel to a main surface of the substrate.

13. The magnetic-field sensor as claimed in claim 1, wherein the first magnetic body and the second magnetic body are both cubic or cylindrical and are arranged in parallel with each other.

14. The magnetic-field sensor as claimed in claim 13, wherein the first magnetic body and the second magnetic body are arranged adjacent to each other.

15. The magnetic-field sensor as claimed in claim 13, wherein the first magnetic body and the second magnetic body are spaced apart from each other by a gap.

16. The magnetic-field sensor as claimed in claim 15, wherein the gap comprises an adhesive, a fastening device or a fixture.

21. The magnetic-field sensor as claimed in claim 8, wherein the first flux density range and the second flux density range are configured to enable operation of the first and second magneto-resistive sensor elements outside a saturation range thereof.

22. The magnetic-field sensor as claimed in claim 1, wherein adjacent areas of the overall magnetic arrangement have magnetizations with different magnetization directions.

23. The magnetic-field sensor as claimed in claim 1, wherein the first magnetic body and the second magnetic body form an overall magnetic arrangement having an inhomogeneous magnetization due to the first and second magnetization directions, and wherein the magnetic-field sensor arrangement is attached to the overall magnetic arrangement.

17. A method of producing a magnetic-field sensor, comprising:

providing a first magnetic body comprising a first magnetization direction, and a second magnetic body comprising a second magnetization direction, the first and second magnetization directions differing, a first spatial area and a second spatial area with regard to the first magnetic body and the second magnetic body existing, so that in the first spatial area, a magnetic flux density is caused by the first magnetic body and the second magnetic body with regard to a predetermined spatial direction, the magnetic flux density being within a first flux density range, and so that in the second spatial area, a magnetic flux density is caused by the first magnetic body and the second magnetic body with regard to the predetermined spatial direction, the magnetic flux density being within a second flux density range; and

providing a magnetic-field sensor arrangement comprising a first and a second magnetic-field sensor element in a sensor plane and attaching the magnetic-field sensor arrangement to the overall magnetic arrangement, so that the first magnetic-field sensor element is arranged in the first spatial area, and the second magnetic-field sensor element is arranged in the second spatial area, and so that the first magnetization direction forms a first angle with a symmetry line, the symmetry line being perpendicular to the sensor plane, and the second magnetization direction forms a second angle with the symmetry line, wherein the first and second angles differ by less than 5°

in magnitude.

18. The method as claimed in claim 17, further comprising determining the first and second spatial areas with regard to the first magnetic body and the second magnetic body.

19. The method as claimed in claim 17, wherein the first and second spatial areas are cubic, wherein the first and second spatial areas comprise lengths of between 300 μ

m and 2000 μ

m with regard to the predetermined spatial direction, and wherein the first and second spatial areas comprise lengths of at least 100 μ

m with regard to a spatial direction perpendicular to the predetermined spatial direction.

20. A non-transitory computer readable digital storage medium having a computer program stored thereon, the computer program comprising a program code for performing, when running on a computer, a method of producing a magnetic-field sensor, the method comprising:

providing a first magnetic body comprising a first magnetization direction, and a second magnetic body comprising a second magnetization direction, the first and second magnetization directions differing, a first spatial area and a second spatial area with regard to the first magnetic body and the second magnetic body existing, so that in the first spatial area, a magnetic flux density is caused by the first magnetic body and the second magnetic body with regard to a predetermined spatial direction, the magnetic flux density being within a first flux density range, and so that in the second spatial area, a magnetic flux density is caused by the first magnetic body and the second magnetic body with regard to the predetermined spatial direction, the magnetic flux density being within a second flux density range; and

providing a magnetic-field sensor arrangement comprising a first and a second magnetic-field sensor element in a sensor plane and attaching the magnetic-field sensor arrangement to the overall magnetic arrangement, so that the first magnetic-field sensor element is arranged in the first spatial area, and the second magnetic-field sensor element is arranged in the second spatial area, and so that the first magnetization direction forms a first angle with a symmetry line, the symmetry line being perpendicular to the sensor plane, and the second magnetization direction forms a second angle with the symmetry line, wherein the first and second angle differ by less than 5°

in magnitude,

when the program runs on a processor.