Magnetic sensor

Patent metadata

Field	Value
Publication number	US-10830838-B2
Application number	US-201816028632-A
Country	US
Kind code	B2
Filing date	Jul 6, 2018
Priority date	Aug 18, 2017
Publication date	Nov 10, 2020
Grant date	Nov 10, 2020

Abstract

A magnetic sensor includes a magnetic field conversion unit, a magnetic field detection unit, and a magnetic film. The magnetic field conversion unit includes a yoke that receives an input magnetic field and generates an output magnetic field. The input magnetic field contains an input magnetic field component in a direction parallel to Z direction. The output magnetic field contains an output magnetic field component in a direction parallel to X direction. The magnetic field detection unit includes a magnetic detection element that receives the output magnetic field and generates a detection value corresponding to the output magnetic field component. The magnetic film absorbs part of magnetic flux resulting from a noise magnetic field, which is a magnetic field in a direction to which the magnetic detection element has sensitivity and which is other than the output magnetic field component.

First claim

What is claimed is:

1. A magnetic sensor comprising: a magnetic field conversion unit; a magnetic field detection unit; and a magnetic film formed of a soft magnetic material, wherein
the magnetic field conversion unit includes a plurality of yokes formed of a soft magnetic material,
each of the plurality of yokes is configured to receive an input magnetic field and generate an output magnetic field, the input magnetic field containing an input magnetic field component in a direction parallel to a first virtual straight line,
the output magnetic field contains an output magnetic field component in a direction parallel to a second virtual straight line intersecting the first virtual straight line, the output magnetic field component varying depending on the input magnetic field component,
the plurality of yokes are aligned spaced from each other in the direction parallel to the second virtual straight line,
the magnetic field detection unit includes at least one magnetic detection element,
the at least one magnetic detection element is configured to receive the output magnetic field and generate a detection value corresponding to the output magnetic field component,
each of the plurality of yokes has a first end and a second end opposite to each other in the direction parallel to the first virtual straight line,
the first end is located closer to the at least one magnetic detection element than is the second end,
the at least one magnetic detection element has a third end and a fourth end opposite to each other in the direction parallel to the first virtual straight
the fourth end is located closer to the plurality of yokes than is the third end,
assuming that there are a first virtual plane including the first end, intersecting the first virtual straight line and being parallel to the second virtual straight line, and a second virtual plane including the fourth end and being parallel to the first virtual plane, the magnetic film is located within a spatial range extending from the first virtual plane to the second virtual plane,
each of the plurality of yokes has a width, the width being a dimension in the direction parallel to the second virtual straight line,
the magnetic film has a thickness and a width, the thickness being a dimension in the direction parallel to the first virtual straight line, the width being a dimension in the direction parallel to the second virtual straight line,
the thickness of the magnetic film is smaller than the width of each of the plurality of yokes, and
the width of the magnetic film is greater than the width of each of the plurality of yokes, and is greater than a distance between two yokes of the plurality of yokes located at opposite ends in the direction parallel to the second virtual straight line.

2. The magnetic sensor according to claim 1 , wherein the magnetic film is in contact with the first end of each of the plurality of yokes.

3. The magnetic sensor according to claim 1 , further comprising a nonmagnetic film formed of a nonmagnetic material and separating the plurality of yokes from the magnetic film.

4. The magnetic sensor according to claim 1 , wherein the second virtual straight line and the first virtual plane are orthogonal to the first virtual straight line.

5. The magnetic sensor according to claim 1 , wherein the thickness of the magnetic film is smaller than or equal to one-half the width of each of the plurality of yokes.

6. A magnetic sensor comprising: a magnetic field conversion unit; a magnetic field detection unit; and a magnetic film formed of a soft magnetic material, wherein
the magnetic field conversion unit includes at least one yoke formed of a soft magnetic material,
the at least one yoke is configured to receive an input magnetic field and generate an output magnetic field, the input magnetic field containing an input magnetic field component in a direction parallel to a first virtual straight line,
the output magnetic field contains an output magnetic field component in a direction parallel to a second virtual straight line intersecting the first virtual straight line, the output magnetic field component varying depending on the input magnetic field component,
the magnetic field detection unit includes at least one magnetic detection element,
the at least one magnetic detection element is configured to receive the output magnetic field and generate a detection value corresponding to the output magnetic field component,
the at least one yoke has a first end and a second end opposite to each other in the direction parallel to the first virtual straight line,
the first end is located closer to the at least one magnetic detection element than is the second end,
the at least one magnetic detection element has a third end and a fourth end opposite to each other in the direction parallel to the first virtual straight line,
the fourth end is located closer to the at least one yoke than is the third end,
assuming that there are a first virtual plane including the first end, intersecting the first virtual straight line and being parallel to the second virtual straight line, a second virtual plane including the fourth end and being parallel to the first virtual plane, and a third virtual plane including the third end and being parallel to the first virtual plane, the magnetic film is located on a side of the third virtual plane such that the at least one magnetic detection element is located between the magnetic film and the at least one yoke along the direction parallel to the first virtual straight line,
the at least one yoke has a width, the width being a dimension in the direction parallel to the second virtual straight line,
the magnetic film has a thickness and a width, the thickness being a dimension in the direction parallel to the first virtual straight line, the width being a dimension in the direction parallel to the second virtual straight line,
the thickness of the magnetic film is smaller than the width of the at least one yoke, and
the width of the magnetic film is greater than the width of the at least one yoke.

7. The magnetic sensor according to claim 6 , wherein a distance between the magnetic film and the third virtual plane is smaller than or equal to a distance between the first virtual plane and the second virtual plane.

8. The magnetic sensor according to claim 6 , wherein the second virtual straight line and the first virtual plane are orthogonal to the first virtual straight line.

9. The magnetic sensor according to claim 6 , wherein the thickness of the magnetic film is smaller than or equal to one-half the width of the at least one yoke.

10. A magnetic sensor comprising: a magnetic field conversion unit; a magnetic field detection unit; and a magnetic film formed of a soft magnetic material, wherein
the magnetic field conversion unit includes a plurality of yokes formed of a soft magnetic material,
the magnetic field detection unit includes at least one magnetic detection element,
each of the plurality of yokes has a first end and a second end opposite to each other in the direction parallel to a first virtual straight line,
the first end is located closer to the at least one magnetic detection element than is the second end,
the at least one magnetic detection element has a third end and a fourth end opposite to each other in the direction parallel to the first virtual straight line,
the fourth end is located closer to the plurality of yokes than is the third end,
the plurality of yokes are aligned spaced from each other in a direction parallel to a second virtual straight line intersecting the first virtual straight line,
assuming that there are a first virtual plane including the first

Assignees

• Tdk Corp

Inventors

• Uchida Keisuke
• Makino Kenzo

Classifications

• G01R33/05 Primary

  in thin-film element · CPC title

• G01R33/02 Primary

  Measuring direction or magnitude of magnetic fields or magnetic flux (G01R33/20 takes precedence) · CPC title