Magnetic sensor

Patent metadata

Field	Value
Publication number	US-9530957-B2
Application number	US-201213446264-A
Country	US
Kind code	B2
Filing date	Apr 13, 2012
Priority date	Dec 2, 2009
Publication date	Dec 27, 2016
Grant date	Dec 27, 2016

Abstract

A magnetic sensor includes magnetoresistive elements and a soft magnetic body. The magnetoresistive elements have multi layers including a magnetic layer and a nonmagnetic layer on a substrate, and exert a magnetoresistance effect. The soft magnetic body is electrically disconnected with the magnetoresistive elements, and converts a vertical magnetic field component from the outside into a magnetic field component in a horizontal direction so as to provide the magnetoresistive elements with the horizontally converted magnetic field component. The magnetoresistive elements have a pinned magnetic layer having a fixed magnetization direction and a free magnetic layer having a variable magnetization direction. The free magnetic layer is stacked on the pinned magnetic layer with a nonmagnetic layer interposed between the free magnetic layer and the pinned magnetic layer. The magnetization directions of the pinned magnetic layers of the magnetoresistive elements are the same direction. The magnetoresistive elements form a bridge circuit.

First claim

What is claimed is:

1. A magnetic sensor comprising:
a plurality of magnetoresistive elements each having a plurality of layers including a magnetic layer and a nonmagnetic layer formed on a substrate defining an X-Y plane, the plurality of magnetoresistive elements having a magnetoresistance effect; and
a plurality of soft magnetic bodies electrically disconnected from the plurality of magnetoresistive elements, the plurality of soft magnetic bodies including:
a plurality of first soft magnetic bodies each converting a vertical Z-direction component of an external magnetic field into a horizontal direction parallel to the X-Y plane so as to provide the plurality of magnetoresistive elements with the horizontally converted magnetic field component, the plurality of first soft magnetic bodies extending in a Y-direction of the X-Y plane and separated from each other in an X-direction of the X-Y plane with a space provided therebetween; and
a pair of second soft magnetic bodies extending in the X-direction and provided on both sides of the plurality of first soft magnetic bodies in the Y-direction, one end of each of the plurality of first soft magnetic bodies being directly connected to one of the pair of second soft magnetic bodies and another end of each of the plurality of first soft magnetic bodies being directly connected to another of the pair of second soft magnetic bodies such that the first and second soft magnetic bodies are integrally formed, the second soft magnetic bodies guiding a horizontal component of the external magnetic field in the X-direction,

wherein each of the plurality of magnetoresistive elements extends in the Y-direction and is provided along one side of one of the plurality of first soft magnetic bodies, the plurality of magnetoresistive elements include at least one first magnetoresistive element disposed, viewed from the Z-direction, in the space between adjacent two first soft magnetic bodies among the plurality of first soft magnetic bodies, the adjacent two first soft magnetic bodies being directly other, the at least one first magnetoresistive element being closer in the X-direction to one of the adjacent two first soft magnetic bodies than to the other of the adjacent two first soft magnetic bodies, such that the one of the adjacent two first soft magnetic bodies is accompanied by the at least one first magnetoresistive element extending along one side thereof, the plurality of magnetoresisive elements including at least one second magnetoresistive element extending along another side of the one of the adjacent two first soft magnetic bodies, the at least one first and second magnetoresistive elements being closer to the one of the adjacent two first soft magnetic bodies in the X-direction than to any other of the plurality of first soft magnetic bodies viewed from the Z-direction.

2. The magnetic sensor according to claim 1 ,
wherein the at least one first magnetoresistive element is disposed along a first edge portion clan undersurface of the one of the adjacent two first soft magnetic bodies and lower than the undersurface.

3. The magnetic sensor according to claim 2 ,
wherein the at least one second magnetoresistive element is disposed along a second edge portion of the undersurface of the one of the adjacent two first soft magnetic bodies and lower than the undersurface, the first and second edge portions being located on opposing sides of the undersurface.

4. The magnetic sensor according to claim 3 ,
wherein each of the plurality of magnetoresistive elements is shorter than the plurality of first soft magnetic bodies in the Y-direction.

5. The magnetic sensor according to claim 1 , further comprising:
an insulating layer formed over the plurality of magnetoresistive elements and the substrate, wherein the plurality of soft magnetic bodies are formed on the insulating layer.

6. The magnetic sensor according to claim 1 , wherein each of the first soft magnetic bodies includes:
a main concentration surface including a top surface of a respective one of the first soft magnetic bodies that concentrates the vertical component of the external magnetic field; and
a main projection surface including a undersurface of respective one of the first soft magnetic bodies that releases the external magnetic field having passed through the respective one of the first soft magnetic bodies as one of the horizontally converted magnetic field components,
and wherein each of the first soft magnetic bodies has an aspect ratio of 1.5 to 4, the aspect ratio being a ratio of a height to a width thereof, the height being a distance between the top surface and the undersurface of the respective one of the first soft magnetic bodies.

Assignees

• Sugihara Shinji
• Koike Fumihito
• Watanabe Yasushi
• Ando Hideto
• Alps Electric Co Ltd

Inventors

• Sugihara Shinji
• Koike Fumihito
• Watanabe Yasushi
• Ando Hideto

Classifications

• G01R33/0206

  Three-component magnetometers · CPC title

• B82Y25/00 Primary

  Nanomagnetism, e.g. magnetoimpedance, anisotropic magnetoresistance, giant magnetoresistance or tunneling magnetoresistance · CPC title

• G01R33/093

  using multilayer structures, e.g. giant magnetoresistance sensors (thin magnetic films H01F10/00) · CPC title

• H01L43/08 Primary

  Electricity · mapped topic

• H10N50/10 Primary

  Magnetoresistive devices · CPC title