Magnetic sensor with elongated soft magnetic body

Patent metadata

Field	Value
Publication number	US-10768246-B2
Application number	US-201816053936-A
Country	US
Kind code	B2
Filing date	Aug 3, 2018
Priority date	Sep 21, 2017
Publication date	Sep 8, 2020
Grant date	Sep 8, 2020

Abstract

A magnetic sensor detects a Z-axis magnetic field via a yoke and enhances the accuracy with which a magnetic field is detected. The magnetic sensor has a first magnetic field detecting element that is arranged in a plane that includes a first direction and a second direction. The second direction is perpendicular to the first direction. The first magnetic field detecting element detects a magnetic field in the first direction. In a soft magnetic body that is adjacent to the first magnetic field detecting element in the first direction, L/W is equal to or more than 10, where W is a length of the soft magnetic body in the first direction, and L is a length of the soft magnetic body in the second direction.

First claim

What is claimed is:

1. A magnetic sensor comprising:
a first magnetic field detecting element that is arranged in a plane that includes a first direction and a second direction that is perpendicular to the first direction, wherein the first magnetic field detecting element detects a magnetic field in the first direction; and
a soft magnetic body that is adjacent to the first magnetic field detecting element in the first direction, wherein
L/W is equal to or more than 10, where W is a length of the soft magnetic body in the first direction, and L is a length of the soft magnetic body in the second direction,
the magnetic sensor further comprises a second magnetic field detecting element that is arranged in a plane that includes the first direction and the second direction, wherein the second magnetic field detecting element detects a magnetic field in the first direction,
each of the first and second magnetic field detecting elements has a magnetic field sensing film that detects a magnetic field in the first direction and a pair of leads that interpose the magnetic field sensing film in a third direction that is perpendicular both to the first direction and to the second direction, and
the soft magnetic body is positioned between the pair of leads of the first magnetic field detecting element and the pair of leads of the second magnetic field detecting element and does not overlap with the pair of leads of the first magnetic field detecting element nor with the pair of leads of the second magnetic field detecting element, as seen in the third direction.

2. The magnetic sensor according to claim 1 , wherein L/W is equal to or more than 20.

3. The magnetic sensor according to claim 1 , wherein 0.27=<h/W=<3, where h is a length of the soft magnetic body in a third direction that is perpendicular both to the first direction and to the second direction.

4. The magnetic sensor according to claim 1 , wherein



V
⁢

⁢
1
⁢

(
H
)

-

V
⁢

⁢
2
⁢

(
H
)



⁢
max

VH
-
VL

≤

1.25
⁢
%

where V 1 (H) is sensor output when external magnetic field whose strength is increasing in a third direction that is perpendicular both to the first direction and to the second direction, V 2 (H) is sensor output when external magnetic field whose strength is decreasing in the third direction and VH and VL are two saturation points of the sensor output.

5. A magnetic sensor comprising:
a first magnetic field detecting element that is arranged in a plane that includes a first direction and a second direction that is perpendicular to the first direction, wherein the first magnetic field detecting element detects a magnetic field in the first direction; and
a soft magnetic body that is adjacent to the first magnetic field detecting element in the first direction, wherein
0.27=<h/W=<3, where W is a length of the soft magnetic body in the first direction, h is a length of the soft magnetic body in a third direction that is perpendicular both to the first direction and to the second direction,
the magnetic sensor further comprises a second magnetic field detecting element that is arranged in a plane that includes the first direction and the second direction, wherein the second magnetic field detecting element detects a magnetic field in the first direction,
each of the first and second magnetic field detecting elements has a magnetic field sensing film that detects a magnetic field in the first direction and a pair of leads that interpose the magnetic field sensing film in a third direction that is perpendicular both to the first direction and to the second direction, and
the soft magnetic body is positioned between the pair of leads of the first magnetic field detecting element and the pair of leads of the second magnetic field detecting element and does not overlap with the pair of leads of the first magnetic field detecting element nor with the pair of leads of the second magnetic field detecting element, as seen in the third direction.

6. The magnetic sensor according to claim 5 , wherein 0.27=<h/W=<1.5.

7. The magnetic sensor according to claim 5 , wherein L/W is equal to or more than 10, where L is a length of the soft magnetic body in the second direction.

8. The magnetic sensor according to claim 5 , wherein



V
⁢

⁢
1
⁢

(
H
)

-

V
⁢

⁢
2
⁢

(
H
)



⁢
max

VH
-
VL

≤

1.25
⁢
%

where V 1 (H) is sensor output when external magnetic field whose strength is increasing in a third direction that is perpendicular both to the first direction and to the second direction, V 2 (H) is sensor output when external magnetic field whose strength is decreasing in the third direction and VH and VL are two saturation points of the sensor output.

Assignees

• Tdk Corp

Inventors

• Uchida Keisuke

Classifications

• G01R33/0206

  Three-component magnetometers · CPC title

• G01R33/093 Primary

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

• G01R33/0005

  Geometrical arrangement of magnetic sensor elements; Apparatus combining different magnetic sensor types (G01R33/0206 takes precedence) · CPC title

• G01R33/063 Primary

  Magneto-impedance sensors; Nanocristallin sensors · CPC title

• G01R33/095

  extraordinary magnetoresistance sensors · CPC title