Magnetic sensor and method of manufacturing the same

Patent metadata

Field	Value
Publication number	US-11067648-B2
Application number	US-201916693546-A
Country	US
Kind code	B2
Filing date	Nov 25, 2019
Priority date	Feb 22, 2017
Publication date	Jul 20, 2021
Grant date	Jul 20, 2021

Abstract

A magnetic sensor that ensures the height of the yoke and that guides magnetic flux in the direction in which the magnetic field sensing film detects a magnetic field includes a first magnetic field detection element that has a first magnetic field sensing film that detects a magnetic field in a first direction, and a first yoke that includes a first portion that is located on a side of the first magnetic field sensing film with respect to the first direction, and a second portion that is in contact with the first portion in a direction that is orthogonal to the first direction. The average dimension of the second portion in the first direction is larger than the average dimension of the first portion in the first direction.

First claim

What is claimed is:

1. A magnetic sensor comprising:
a first magnetic field detection element that has a first magnetic field sensing film that detects a magnetic field in a first direction; and
a yoke that includes a first portion and a second portion that is in contact with the first portion in a direction that is orthogonal to the first direction,
wherein an average dimension of the second portion in the first direction is larger than an average dimension of the first portion in the first direction, and
the yoke is made of a soft magnetic material.

2. The magnetic sensor according to claim 1 , wherein the first portion terminates on a side of the second portion with regard to the first magnetic field sensing film, when viewed from the second portion in the direction that is orthogonal to the first direction.

3. The magnetic sensor according to claim 1 , wherein
the yoke is a first yoke, and the magnetic sensor further comprises a second yoke that is located on a side opposite to the first yoke with respect to the first magnetic field sensing film, and
the second yoke lies on an extended line of a straight line that connects a center of the first yoke to a center of the first magnetic field sensing film.

4. The magnetic sensor according to claim 1 , further comprising a second magnetic field detection element that has a second magnetic field sensing film that detects a magnetic field in the first direction, wherein the second magnetic field detection element is located away from the first magnetic field detection element in the first direction, wherein the first portion is located substantially halfway between the first magnetic field sensing film and the second magnetic field sensing film.

5. The magnetic sensor according to claim 1 , wherein a surface of the first portion that faces the first magnetic field sensing film has a curved surface that is recessed in a direction of retreating from the first magnetic field sensing film.

6. The magnetic sensor according to claim 1 , wherein the first magnetic field sensing film includes a magnetization free layer in which a magnetization direction relative to external magnetic field rotates in a plane that includes the first direction, a magnetization fixed layer in which a magnetization direction is fixed relative to the external magnetic field, and a spacer layer that is sandwiched between the magnetization free layer and the magnetization fixed layer and that has magnetoresistive effect.

7. The magnetic sensor according to claim 4 , wherein the first portion terminates on a side of the second portion with regard to the first magnetic field sensing film and the second magnetic field sensing film, when viewed from the second portion in the direction that is orthogonal to the first direction.

8. The magnetic sensor according to claim 7 , further comprising a third yoke that is located on a side opposite to the first yoke with respect to second magnetic field sensing film, the third yoke lying on an extended line of a straight line that connects a center of the first yoke to a center of the second magnetic field sensing film.

Assignees

• Tdk Corp

Inventors

• Ohta Naoki
• Takasugi Keisuke

Classifications

• G01R33/093 Primary

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

• G01R33/05

  in thin-film element · CPC title

• H01R43/12

  Manufacture of brushes · CPC title

• G01R33/0052

  Manufacturing aspects; Manufacturing of single devices, i.e. of semiconductor magnetic sensor chips (devices based on galvano-magnetic effect or the like H10N50/85) · CPC title

• H10N50/00 Primary

  Galvanomagnetic devices (Hall-effect devices H10N52/00; integrated devices or assemblies of multiple devices H10N59/00) · CPC title