JP2016090325A - Magnetic sensor - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a magnetic sensor which enables further accurate regularization for fixing a magnetization direction of each pinned layer by placing magnetoresistance effect elements near an outer periphery of a substrate while maintaining intensity of magnetic field generated from each effective area.SOLUTION: Parts disposed below each magnetoresistance effect element 25 constitute a coil 26 comprising first and second coil units 31 and 32 configured to let current flow in the same direction, where the number of turns of the first coil unit 31 is less than 1/2 of a sum of the numbers of turns of the first and second coil units 31 and 32 and equal to or more than 1. Each first coil unit 31 is disposed along an outer periphery of a substrate 11.SELECTED DRAWING: Figure 1

Description

  The present invention relates to a magnetic sensor.

Conventionally, a magnetic sensor employing a magnetoresistive effect element such as a giant magnetoresistive effect element (GMR element) or a magnetic tunnel effect element (TMR element) as a magnetic field detecting element is known.
The magnetic sensor has a rectangular substrate and a magnetic field detection element. Among the magnetic field detecting elements, the magnetoresistive effect element has a laminated structure including a pinned layer in which the direction of magnetization is fixed in a predetermined direction, and a free layer in which the direction of magnetization changes according to a magnetic field from the outside, Has been.

The magnetic sensor may have a coil (hereinafter referred to as “symmetric coil”) configured by connecting two coil portions having the same number of turns for applying a bias magnetic field to the magnetoresistive element.
The coil is composed of a conductive wire arranged in a spiral shape. And a magnetoresistive effect element is arrange | positioned through the insulating layer in the effective area | region between the vortex center position of one coil part, and the vortex center position of the other coil part.
A bias magnetic field for the magnetoresistive effect element is generated by a current flowing through a conducting wire arranged immediately below the magnetoresistive effect element.

JP 2009-20117 A

By the way, when the magnetic sensor is manufactured, the magnetoresistive effect element is ordered to fix the magnetization direction of the pinned layer.
Here, the ordering process for fixing the magnetization direction of the pinned layer will be described by taking as an example a case where a magnetoresistive effect element is manufactured at an intermediate position of each side of a rectangular substrate.
In this case, by using a permanent magnet group (hereinafter referred to as “magnet array”) composed of permanent magnet pieces (a total of four permanent magnet pieces) arranged near the four corners of the substrate, the magnetization direction of the pinned layer is determined. Make regularization to fix.
At this time, from the viewpoint of improving the regularity of the magnetization direction of the pinned layer, it is preferable to dispose the magnetoresistive element close to the outer periphery of the substrate where the magnetic field formed by the magnet array is straight.

However, in the magnetic sensor having a symmetric coil disclosed in Patent Document 1, there are many portions between the effective region and the outer periphery of the substrate that do not directly contribute to the formation of the bias magnetic field. It has been difficult to reduce the distance from the periphery to the center of the magnetoresistive element (in other words, disposing the magnetoresistive element close to the outer periphery of the substrate).
Therefore, the conventional magnetic sensor has been required to be improved because the magnetization direction of the pinned layer in the magnetoresistive effect element is disturbed and it is difficult to obtain a desired detection accuracy.

  Therefore, an object of the present invention is to provide a magnetic sensor capable of obtaining good detection accuracy.

  In order to solve the above problems, according to one aspect of the present invention, a substrate, a first coil portion disposed on the substrate and having a spiral shape, and a spiral in a direction opposite to the first coil portion are provided. A coil formed of a second coil portion that is shaped and connected to the first coil portion; an insulating layer provided to cover the coil; and the first coil on the insulating layer A pinned layer in which the direction of magnetization is fixed to a predetermined direction and a direction in which the direction of magnetization changes according to an external magnetic field And the coil is configured such that current flows in the same direction at a portion disposed below the magnetoresistive element, and the coil is wound around the first coil portion. The number of turns of the first and second coil sections. Less than half of, and while one or more magnetic sensors, wherein the disposing the first coil portion on the outer periphery of the substrate.

  In the magnetic sensor of the present invention, the first coil portion is constituted by a first conductive wire arranged in a spiral shape, and the second coil portion is a second conductive wire arranged in a spiral shape. Of the first and second conductors, the portion disposed below the magnetoresistive element is disposed so as to extend in a direction parallel to the magnetization direction of the pinned layer. Also good.

  In the magnetic sensor of the present invention, the coil may generate a magnetic field that initializes the magnetization direction of the free layer.

  According to the present invention, it is possible to provide a magnetic sensor capable of obtaining good detection accuracy.

It is a top view which shows schematic structure of the magnetic sensor which concerns on embodiment of this invention. It is the top view to which the part enclosed by the area | region A shown in FIG. 1 was expanded. It is sectional drawing of the BB line direction of the magnetic sensor shown in FIG. FIG. 2 is an enlarged plan view of a part of the magnetoresistive effect element shown in FIG. 1. It is sectional drawing of the FF line direction of the magnetoresistive effect element shown in FIG. It is a top view for demonstrating the structure of the conventional magnetic sensor. It is a top view for demonstrating an example of the regularization process for fixing the magnetization direction of a pinned layer.

  Embodiments to which the present invention is applied will be described below in detail with reference to the drawings. The drawings used in the following description are for explaining the configuration of the embodiment of the present invention, and the size, thickness, dimensions, etc. of each part shown in the drawings may be different from the dimensional relationship of an actual magnetic sensor. is there.

(Embodiment)
FIG. 1 is a plan view showing a schematic configuration of a magnetic sensor according to an embodiment of the present invention. FIG. 2 is an enlarged plan view of a portion surrounded by a region A shown in FIG.
1 and 2, C1 is a vortex center position of the first coil portion 31 (hereinafter referred to as “vortex center position C1”), and C2 is a vortex center position of the second coil portion 32 (hereinafter referred to as “vortex center position”). C3 ”and C3 are vortex center positions of the first coil portion 44 (hereinafter referred to as“ vortex center positions C3 ”), and C4 is a vortex center position of the second coil portion 45 (hereinafter referred to as“ vortex center position C4 ”). D is an effective region in which the magnetoresistive effect element 25 is disposed (hereinafter referred to as “effective region D”), and E is a distance from the center of the magnetoresistive effect element 25 to the outer periphery of the substrate 11 (hereinafter referred to as “distance E”). ").
3 is a cross-sectional view of the magnetic sensor shown in FIG. 2 in the BB line direction. 1 to 3, the X direction is the extending direction of the sides 11C and 11D of the substrate 11, the Y direction is the extending direction of the sides 11A and 11B of the substrate 11, and the direction perpendicular to the X direction is the Z direction. 11 shows the thickness direction. 1 to 3, the same reference numerals are given to the same components.

1 to 3, the magnetic sensor 10 includes a substrate 11, an insulating layer 12, and sensor units 14 to 17.
The substrate 11 has a rectangular shape and includes sides 11 </ b> A to 11 </ b> D, a substrate body 21, and a coil forming layer 22. The sides 11A and 11B are sides that extend in the Y direction and are opposed to each other in the X direction. The sides 11C and 11D are sides that extend in the X direction and are opposed to each other in the Y direction.
The substrate body 21 is a base material having a rectangular shape, and for example, a single crystal silicon substrate can be used.

The coil forming layer 22 is a layer in which coils 26 and 41 (to be described later) constituting the sensor units 14 to 17 are formed on the upper surface thereof.
The coil forming layer 22 may be a single insulating layer or a multilayer wiring structure in which a plurality of insulating layers are stacked. When a multilayer structure is used as the coil forming layer 22, the uppermost layer on which the coils 26 and 41 are formed is formed of an insulating layer.

  The insulating layer 12 is provided on the upper surface of the coil forming layer 22 (in other words, the upper surface of the substrate 11) so as to cover the coils 26 and 41. The insulating layer 12 insulates between the coils 26 and 41 and magnetoresistive elements 25 and 42 (described later) disposed above the coils 26 and 41.

  The sensor units 14 and 15 are sensor units having the same configuration. The sensor unit 14 is disposed at the center of the side 11 </ b> A of the substrate 11. The sensor unit 15 is disposed at the center of the side 11 </ b> B of the substrate 11. Thereby, the sensor parts 14 and 15 are arrange | positioned so that it may oppose in a X direction.

  The sensor units 14 and 15 have a magnetoresistive effect element 25 disposed on the insulating layer 12 and a coil 26 disposed on the upper surface of the substrate 11.

  FIG. 4 is an enlarged plan view of a part of the magnetoresistive effect element shown in FIG. FIG. 5 is a cross-sectional view of the magnetoresistive effect element shown in FIG. 4 in the FF line direction. In FIG. 5, the same components as those of the structure shown in FIG.

2 to 5, the magnetoresistive element 25 is provided on the insulating layer 12 corresponding to the effective region D. Below the magnetoresistive effect element 25, a plurality of first and second conducting wires 34, 35 extending in the Y direction are arranged.
The magnetoresistive effect element 25 has a plurality of narrow strip portions 47 and a plurality of bias magnet films 48. The plurality of narrow strip portions 47 are arranged at a predetermined interval with respect to the Y direction so that the longitudinal direction thereof is the X direction.

The narrow strip portion 47 is a spin valve structure, and on the insulating layer 12, a free layer 51 (free magnetic layer), a conductive spacer layer 52, a pinned layer 53 (fixed magnetic layer), and a capping layer 54. Are sequentially stacked.
The free layer 51 is a layer whose magnetization direction changes according to an external magnetic field. As a material of the conductive spacer layer 52, for example, Cu can be used. The pinned layer 53 (fixed magnetization layer) is a layer in which the direction of magnetization is fixed in a predetermined direction.
The plurality of bias magnet films 48 are connected to the two end portions of the narrow strip portions 47 arranged at adjacent positions in the Y direction.

  Note that the structure shown in FIG. 4 is an example, and the structure is not limited to this structure.

Referring to FIGS. 1 to 3, the coil 26 includes a first coil part 31 and a second coil part 32 having one end connected to the first coil part 31. The coil 26 has a function of generating a bias magnetic field when energized and initializing the magnetization direction of the free layer 51 (see FIG. 5) by applying a bias magnetic field to the magnetoresistive effect element 25.
The first and second coil portions 31 and 32 have a substantially rectangular spiral shape. The first coil portion 31 is configured by winding the first conductive wire 34. Further, the second coil portion 32 is configured by winding the second conductive wire 35.
Of the first and second conducting wires 34 and 35, the portion disposed below the magnetoresistive effect element 25 extends in a direction parallel to the magnetization direction of the pinned layer 53 shown in FIG. Has been placed.

The number of turns of the first coil unit 31 is configured to be less than ½ of the total number of turns of the first and second coil units 31 and 32 and greater than 1. Further, the number of turns of the second coil part 32 is more than ½ of the total number of turns of the first and second coil parts 31 and 32. For example, the number of turns of the first coil unit 31 can be set to four, and the number of turns of the second coil unit 32 can be set to eight. Thereby, the outer size of the first coil part 31 is smaller than the outer size of the second coil part 32.
Note that the number of turns of the first and second coil portions 31 and 32 can be appropriately set in consideration of the symmetry of the generated magnetic field and the area occupied by the coil 26.

The first coil unit 31 constituting the sensor unit 14 is disposed in the vicinity of the side 11 </ b> A of the substrate 11, and the second coil unit 32 is disposed on the plan view center side of the substrate 11.
Similarly, the first coil unit 31 constituting the sensor unit 15 is disposed in the vicinity of the side 11B (side opposite to the side 11A) of the substrate 11, and the second coil unit 32 is provided on the substrate 11 side. It is arranged on the center side in plan view.
In this way, the first coil portion 31 is set to a number of turns that is less than ½ of the total number of turns of the first and second coil portions 31 and 32 and greater than 1, and the outer size is reduced. Is arranged on the outer periphery of the substrate 11 (in other words, close to the sides 11A and 11B), compared with the case where the first coil portion 31 and the second coil portion 32 have the same number of turns. The magnetoresistive element 25 can be disposed in the vicinity of the outer periphery of the substrate 11.

The sensor unit 14 may have four magnetoresistive elements 25 in the effective region D, and the sensor unit 15 may have four magnetoresistive elements 25 in the effective region.
In this case, the Y-axis magnetoresistive effect for detecting the magnetism in the Y-axis direction is obtained by using the element group including the two magnetoresistive effect elements 25 constituting the sensor unit 14 and the two magnetoresistive effect elements 25 constituting the sensor unit 15. It can be used as an element. These four magnetoresistive elements 25 are preferably bridge-connected.
In addition, an element group consisting of the remaining two magnetoresistive effect elements 25 constituting the sensor unit 14 and the remaining two magnetoresistive effect elements 25 constituting the sensor unit 15 is used as a Z-axis magnetoresistive for detecting magnetism in the Z-axis direction. It can be set as an effect element. These four magnetoresistive elements 25 are preferably bridge-connected.
The position where the Y-axis magnetoresistive element and the Z-axis magnetoresistive element are formed may be inclined with respect to the surface of the substrate 11.

  Referring to FIG. 1, the sensor units 16 and 17 are sensor units having the same configuration. The sensor unit 16 is disposed at the center of the side 11 </ b> C of the substrate 11. The sensor unit 17 is disposed at the center of the side 11 </ b> D of the substrate 11. Thereby, the sensor parts 16 and 17 are arrange | positioned so that it may oppose in a Y direction.

The sensor units 16 and 17 include a coil 41 disposed on the upper surface of the substrate 11 and a magnetoresistive effect element 42 disposed on the insulating layer 12.
The coil 41 is an asymmetric double spiral coil, and is a first coil portion 44 and a second coil having one end connected to the first coil portion 44 and having a larger number of turns than the first coil portion 44. Part 45.
The coil 41 has a function of generating a bias magnetic field when energized and initializing the magnetization direction of the free layer 51 (see FIG. 5) by applying a bias magnetic field to the magnetoresistive effect element 25.

The first coil unit 44 has the same configuration as the first coil unit 31 described above. Note that the first coil unit 44 may have a different number of turns and outer size than the first coil unit 31.
The second coil unit 45 has the same configuration as the second coil unit 45 described above. Note that the second coil unit 45 may have a different number of turns and outer size than the second coil unit 32.

The magnetoresistive element 42 is disposed in an effective region (not shown) formed between the vortex center position C3 of the first coil portion 44 and the vortex center position C4 of the second coil portion 45.
The magnetoresistive effect element 42 includes a plurality of narrow strip portions 47 and a bias magnet film 48, and the number of the narrow strip portions 47 and the bias magnet film 48 constituting the magnetoresistive effect element 25. The magnetoresistive element 25 is configured in the same manner as the magnetoresistive element 25 except that the number is different from the number.
The plurality of narrow strip portions 47 in the magnetoresistive effect element 42 are arranged at a predetermined interval with respect to the X direction so that the longitudinal direction thereof is the Y direction.

  The number of turns of the first coil unit 44 is configured to be less than ½ of the total number of turns of the first and second coil units 44 and 45 and greater than 1. Further, the number of turns of the second coil part 45 is larger than ½ of the total number of turns of the first and second coil parts 44 and 45. Thereby, the outer size of the first coil unit 44 is smaller than the outer size of the second coil unit 45.

The first coil part 44 constituting the sensor part 16 is disposed in the vicinity of the side 11 </ b> C of the substrate 11, and the second coil part 45 is disposed on the center side of the substrate 11 in plan view.
Similarly, the first coil unit 44 constituting the sensor unit 17 is disposed in the vicinity of the side 11D of the substrate 11 (side opposite to the side 11C), and the second coil unit 45 is formed on the substrate 11. It is arranged on the center side in plan view.
In this way, the first coil portion 44 is set to a number of turns smaller than ½ of the total number of turns of the first and second coil portions 44 and 45 and larger than 1, and the outer size is reduced. Is arranged on the outer periphery of the substrate 11 (in other words, close to the sides 11C and 11D), compared with the case where the first coil portion 44 and the second coil portion 45 have the same number of turns. The magnetoresistive element 25 can be disposed in the vicinity of the outer periphery of the substrate 11.

The sensor unit 16 may have two magnetoresistive elements 25 in the effective region, and the sensor unit 17 may have two magnetoresistive elements 25 in the effective region.
In this case, an element group of the two magnetoresistive effect elements 25 in the sensor unit 16 and the two magnetoresistive effect elements 25 in the sensor unit 17 is an X-axis magnetoresistive effect element that detects magnetism in the X-axis direction. Can do. The four magnetoresistive effect elements 25 are preferably bridge-connected.

  The magnetic sensor 10 having the above-described configuration can obtain a good detection accuracy because the pinning layer of the magnetoresistive effect element can be regularly ordered to fix the magnetization direction at the time of manufacture.

  Hereinafter, in order to explain the effect of the magnetic sensor 10 of the present invention, first, the structure of the conventional magnetic sensor will be described with reference to the drawings, and the structure of the magnetic sensor 10 and the conventional magnetic sensor will be compared and ordered. Processing will be described.

  FIG. 6 is a plan view for explaining the configuration of a conventional magnetic sensor, and corresponds to FIG. In the following description, the magnetic sensor 10 of the present application is compared with the conventional magnetic sensor 100 with reference to FIG. 2 and FIG. 6, but the other sensor units 15 to 17 not shown in FIG. The same effect as the sensor unit 14 shown in FIG.

In FIG. 6, P is an effective region (hereinafter referred to as “effective region P”) in which the magnetoresistive effect element 102 can be disposed, and Q1 is a vortex center position (hereinafter, referred to as “effective region P”) of the first coil portion 103 constituting the double spiral coil 101. (Referred to as “vortex center position Q 1”), Q 2 is the position of the vortex center of the second coil portion 104 constituting the double spiral coil 101 (hereinafter referred to as “vortex center position Q 2”), and S is the magnetic resistance from the outer periphery of the substrate 110. The distance to the center of the effect element 102 (hereinafter referred to as “distance S”) is shown.
In FIG. 6, the X direction is a direction orthogonal to the Y direction, the Y direction is the extending direction of the first and second conducting wires 106 and 107 in the effective region P, and the Z direction is the thickness direction of the substrate 110. Yes.

  Referring to FIG. 6, a conventional magnetic sensor 100 includes a symmetrical coil 101 having first and second coil portions 103 and 104 having substantially the same size and the same number of turns, and first and first coils. Magnetoresistive effect element 102 disposed between the vortex center positions Q1 and Q2 of the two coil portions 103 and 104. In FIG. 6, as an example, the case where the number of turns of the first and second coil portions 103 and 104 is set to 6 times is shown as an example.

  In the magnetic sensor 100, a current is passed in the same direction to the first and second conducting wires 106 and 107 that are located immediately below the magnetoresistive effect element 102 and constitute the first and second coil portions 103 and 104. It is said that.

  In such a magnetic sensor 100, the total number of turns of the first coil unit 103 and the second coil unit 104 is equal to the number of turns of the first coil unit 31 and the second coil shown in FIG. It is equal to the sum of the number of turns of the section 32.

Therefore, the effective area D formed between the vortex center position C1 of the first coil section 31 shown in FIG. 2 and the vortex center position C2 of the second coil section 32 and the effective area P shown in FIG. The size is almost the same.
Thereby, the magnitude of the generated magnetic field intensity generated from the effective area D of the coil 26 (asymmetric double spiral coil) shown in FIG. 2 and the effective area P of the coil 101 (symmetric double spiral coil) shown in FIG. The magnitude of the generated magnetic field intensity is substantially the same.

  In addition, the magnetoresistive effect element is disposed in the effective region in both the magnetic sensor 10 and the magnetic sensor 100. Therefore, in both the magnetic sensor 10 and the magnetic sensor 100, the generated magnetic field strength received by the magnetoresistive element is substantially the same.

  On the other hand, the distance E from the center of the magnetoresistive effect element 25 to the outer periphery of the substrate 11 in the magnetic sensor 10 shown in FIG. 2 is the outer periphery of the substrate 110 from the center of the magnetoresistive effect element 102 in the magnetic sensor 100 shown in FIG. Is shorter than the distance S.

FIG. 7 is a plan view for explaining an example of the ordering process for fixing the magnetization direction of the pinned layer. In FIG. 7, the same components as those of the structure shown in FIG.
As shown in FIG. 7, when the ordering process for fixing the magnetization direction of the pinned layers constituting the magnetoresistive effect elements 25 and 42 is performed, the permanent magnet group ( Magnet array).

The permanent magnet pieces 62 to 65 are disposed below the substrate 11 (on the −z side) at the four corners of the substrate 11 that is rectangular. The permanent magnet pieces arranged at adjacent positions along the side of the substrate 11 are arranged so that the magnetic poles facing the substrate 11 are different.
For example, when the permanent magnet pieces 62 and 64 arranged diagonally on the substrate 11 are arranged with the N pole facing the substrate 11, the permanent magnet pieces 63 and 65 arranged on the remaining corners of the substrate 11 are , S pole is arranged toward the substrate 11.
In the present embodiment, as an example, the case where the permanent magnet pieces 62 and 64 are arranged with the N pole facing the substrate 11, and the permanent magnet pieces 63 and 65 are arranged with the S pole facing the substrate 11. The following explanation is given by way of example.
In the case of the above configuration, a magnetic field is formed in the direction from the permanent magnet pieces 62 and 64 to the permanent magnet pieces 63 and 65, and the pinned layer constituting the magnetoresistive effect elements 25 and 42 is ordered by the magnetic field.
Moreover, in the said regularization process, after arrange | positioning a permanent magnet piece as mentioned above, it heat-processes.

  In the magnetic sensor 10 of the present invention, the distance from the center of the magnetoresistive effect elements 25 and 42 to the outer periphery of the substrate 11 is from the center of the magnetoresistive effect element 102 to the outer periphery of the substrate 110 in the magnetic sensor 100 shown in FIG. Since the distance is shorter than the distance S, the magnetoresistive elements 25 and 42 can be arranged close to the outer periphery of the substrate 11.

Thus, when the magnetic sensor 10 of the present invention is subjected to ordering processing, the magnetization direction of the pinned layers constituting the magnetoresistive effect elements 25 and 42 is fixed using a straight magnetic field formed by the permanent magnet group. It becomes possible.
In the magnetic sensor 10 shown in the present embodiment, the plurality of narrow strip portions 47 constituting the magnetoresistive element 25 are arranged such that the longitudinal direction thereof is the X direction. Therefore, in the magnetic sensor 10 according to the present embodiment shown in FIG. 7, the magnetization direction of the pinned layer is orthogonal to the longitudinal direction of the narrow band portion 47 constituting the magnetoresistive effect element 25 by the ordering process. It will be.
Similarly, the plurality of narrow strip portions 47 constituting the magnetoresistive element 42 are arranged such that the longitudinal direction thereof is the Y direction. Therefore, in the magnetic sensor 10 according to the present embodiment shown in FIG. 7, the magnetization orientation of the pinned layer is orthogonal to the longitudinal direction of the narrow strip portion 47 constituting the magnetoresistive effect element 42 by the ordering process. It will be.
For the reason described above, the magnetic sensor 10 of the present invention can be a pinned layer with high accuracy and a magnetic sensor with good detection accuracy.

As described above, the magnetic sensor according to the present embodiment is arranged on the substrate 11 and has a spiral shape in the direction opposite to the first coil portions 31 and 44 having a spiral shape and the first coil portions 31 and 44. The coils 26 and 41 are formed of the second coil portions 32 and 45 which are shaped and integrated with the first coil portions 31 and 44.
Further, it is disposed between the vortex center positions C1 and C3 of the first coil portions 31 and 44 and the vortex center positions C2 and C4 of the second coil portions 32 and 45 via the insulating layer 12, and the direction of magnetization. Have magnetoresistive elements 25 and 42 including a pinned layer fixed in a predetermined orientation and a free layer whose magnetization direction changes according to an external magnetic field.
In addition, the coils 26 and 41 are configured such that current flows in the same direction in portions disposed below the magnetoresistive elements 25 and 42. The number of turns of the first coil parts 31 and 44 is less than ½ of the total number of turns of the first coil parts 31 and 44 and the second coil parts 32 and 45 and is 1 or more. It is configured. The first coil portions 31 and 44 are disposed on the outer periphery of the substrate 11.
With the above configuration, it is possible to place the magnetoresistive elements 25 and 42 close to the outer periphery of the substrate 11 while maintaining the generated magnetic field intensity generated from the effective region D. Thus, the ordering for fixing the magnetization direction of the pinned layer can be performed with high accuracy, and the magnetic sensor can be obtained with good detection accuracy.

  The preferred embodiments of the present invention have been described in detail above, but the present invention is not limited to such specific embodiments, and within the scope of the present invention described in the claims, Various modifications and changes are possible.

  The arrangement positions of the sensor units 14 to 17 in the present embodiment are merely examples, and are not limited to the arrangement positions of the sensor units 14 to 17 illustrated in FIG. The arrangement positions of the sensor units 14 to 17 can be appropriately selected on the substrate 11.

  Further, in the present embodiment, a case where an asymmetric double spiral coil (coils 26, 41) is applied to two sensor units arranged in the X direction and two sensor units arranged in the Y direction. Although described as an example, an asymmetrical double spiral coil (coils 26, 41) may be applied to only two sensor units arranged in one of the X direction and the Y direction. In this case, the same effect as that of the present embodiment can be obtained.

  The present invention can be applied to a sensor unit having a magnetoresistive effect element including a pinned layer and a free layer, and a coil including first and second coil units.

  DESCRIPTION OF SYMBOLS 10 ... Magnetic sensor, 11 ... Board | substrate, 11A-11D ... Side | side, 12 ... Insulating layer, 14-17 ... Sensor part, 21 ... Substrate body, 22 ... Coil formation layer, 25, 42 ... Magnetoresistive effect element, 26, 41 ... Coil, 31, 44 ... First coil part, 32, 45 ... Second coil part, 34 ... First conductor, 35 ... Second conductor, 47 ... Narrow strip, 48 ... Bias magnet film, DESCRIPTION OF SYMBOLS 51 ... Free layer, 52 ... Conductive spacer layer, 53 ... Pinned layer, 54 ... Capping layer, 62-65 ... Permanent magnet piece, C1-C4 ... Vortex center position, D ... Effective area, E ... Distance

Claims (3)

A substrate,
A first coil portion disposed on the substrate and having a spiral shape, and a second coil having a spiral shape opposite to the first coil portion and connected to the first coil portion A coil consisting of parts,
An insulating layer provided to cover the coil;
A pinned layer on the insulating layer, disposed between a vortex center position of the first coil portion and a vortex center position of the second coil portion, and having a magnetization direction fixed in a predetermined direction; A magnetoresistive effect element including a free layer in which the direction of magnetization changes according to an external magnetic field;
Have
The coil is configured such that current flows in the same direction in a portion disposed below the magnetoresistive element,
The number of turns of the first coil portion is less than ½ of the total number of turns of the first and second coil portions and 1 or more, and the first coil is disposed on the outer periphery of the substrate. A magnetic sensor characterized in that a portion is arranged. The first coil portion is composed of first conductive wires arranged in a spiral shape,
The second coil portion is composed of second conductive wires arranged in a spiral shape,
The portion of the first and second conductive wires disposed below the magnetoresistive element is disposed so as to extend in a direction parallel to the magnetization direction of the pinned layer. Item 2. The magnetic sensor according to Item 1.   The magnetic sensor according to claim 1, wherein the coil generates a magnetic field that initializes a magnetization direction of the free layer.

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