MAGNETIC SENSOR

• US 20170276739A1
• Filed: 02/15/2017
• Published: 09/28/2017
• Est. Priority Date: 03/23/2016
• Status: Active Grant

• Current Assignee: Alps Alpine Co., Ltd.
• Original Assignee: ALPS Electric Company Limited (Alps Alpine Co., Ltd.)
• Inventors: OBANA, Masayuki, ANDO, Hideto, IMAI, Yuki, YAMANAKA, Kunio, HOTTA, Kyoko, MIYATAKE, Akira, KOBAYASHI, Toshihiro, IKEDA, Kenichiro, NOGUCHI, Takafumi
• Granted Patent: US 10,444,303 B2
• Time in Patent Office: Days
• CPC Class Codes: G01C 21/08 involving use of the magnetic field of the earth
• CPC Class Codes: G01R 33/0011 comprising means, e.g. flux concentrators, flux guides, for guiding or concentrating the magnetic flux, e.g. to the magnetic sensor
• CPC Class Codes: G01R 33/091 Constructional adaptation of the sensor to specific applications

Abstract

A magnetic sensor including a first magneto resistive effect element located on a first surface of a substrate and having a sensitivity axis in a first direction that is one of in-plane directions of the first surface, a positioning soft magnetic body including a first most proximal portion of which a relative position with respect to the magneto resistive effect element is defined, and provided in a non-contact manner with respect to the first magneto resistive effect element, and a first soft magnetic body and a second soft magnetic body juxtaposed in the first direction and extending in a direction away from the first surface, and each of the first soft magnetic body and the second soft magnetic body is magnetically connected to the positioning soft magnetic body.

Claims

1. A magnetic sensor, comprising:

a substrate having a first surface;

a magneto resistive effect element disposed on the first surface of the substrate, the magneto resistive effect element having a sensitivity axis in a first direction and extending in a second direction perpendicular to the first direction;

a positioning soft magnetic body extending in the second direction and provided for the magneto resistive effect element without being in contact therewith, the positioning soft magnetic body having a most proximal portion defined with respect to the magneto resistive effect element; and

a pair of first and second soft magnetic bodies extending in the second direction and adjacent to each other in the first direction in a plan view from above the first surface, the first and second magnetic bodies extending in a respective direction away from the first surface viewed in a cross section perpendicular to the second direction,

wherein the first and second soft magnetic bodies are magnetically connected to the positioning soft magnetic body.

2. The magnetic sensor according to claim 1,

wherein the most proximal portion of the positioning soft magnetic body is a side surface thereof perpendicular the first surface.

3. The magnetic sensor according to claim 1,

wherein the first and second soft magnetic bodies are formed integrally via a connection portion provided therebetween, and a width of the positioning soft magnetic body in the first direction is greater than a width of the connection portion in the first direction.

4. The magnetic sensor according to claim 1,

wherein, in the plan view from above the first surface, the most proximal portion of the positioning magnetic body falls within the magneto resistive effect element.

5. The magnetic sensor according to claim 1,

wherein a thickness of the positioning soft magnetic body in a third direction perpendicular to the first surface is 5 μ

m or less.

6. The magnetic sensor according to claim 1,

wherein the first and second soft magnetic bodies are inclined toward opposite sides of a center position therebetween in the first direction.

7. The magnetic sensor according to claim 1,

wherein a distance between the first and second soft magnetic bodies increases as a respective distance of the first and second soft magnetic bodies from the first surface increases.

8. The magnetic sensor according to claim 1, further comprising:

an insulating nonmagnetic body provided on the first surface,

wherein the pair of soft magnetic bodies are formed on an upper a surface of the insulating nonmagnetic body.

9. The magnetic sensor according to claim 8,

wherein the most proximal portion of the positioning soft magnetic body is surrounded by the insulating nonmagnetic body.

10. The magnetic sensor according to claim 1,

wherein each of the first and second soft magnetic bodies further includes an extension portion extending in the first direction from a respective side thereof opposite to an inner side thereof which is magnetically connected to the positioning soft magnetic body.

11. The magnetic sensor according to claim 1, wherein:

the magneto resistive effect element includes a first part proximal to the first soft magnetic body, and a second part extending parallel to the first part and proximal to the second soft magnetic body,

each of the first and second parts of the magneto resistive effect element includes;

a fixed magnetic layer in which magnetization is fixed in a direction parallel to the first direction, and

a free magnetic layer in which a magnetization direction thereof is changed by an external magnetic field applied thereto, and

a fixed magnetization direction of the fixed magnetic layer in the first part and a fixed magnetization direction of the fixed magnetic layer in the second part are aligned with each other.

12. The magnetic sensor according to claim 11,

wherein the first and second parts of the magneto resistive effect element are connected in series to constitute a half bridge circuit.

13. A magnetic sensor device formed of two magnetic sensors each according to claim 12,

wherein two half bridge circuits of the two magnetic sensors constitute a full bridge circuit.

14. The magnetic sensor device according to claim 13,

wherein the two first parts of the magneto resistive effect elements and the two second parts of the magneto resistive effect elements included in the full bridge circuit are arranged so as to aligned in the first direction.