Magnetic sensor

Abstract

Magnetic sensor (1; 101), comprising: at least one magnetoresistive element (11, 12, 13, 14) whose resistance changes with an external magnetic field; and a coil (30) generating a coil magnetic field, wherein the coil magnetic field is a magnetic field to be applied to the at least one magnetoresistive element (11, 12, 13, 14), wherein the coil (30) has at least one conductor section (31, 32, 33, 34; 31A, 31B, 32A, 32B, 33A, 33B, 34A, 34B), the coil magnetic field contains a partial magnetic field generated by each of the at least one conductor section (31, 32, 33, 34; 31A, 31B, 32A, 32B, 33A, 33B, 34A, 34B), the partial magnetic field generated by each of the at least one conductor section (31, 32, 33, 34; 31A, 31B, 32A, 32B, 33A, 33B, 34A, 34B) is applied to a corresponding one of the at least one magnetoresistive element (11, 12, 13, 14), the corresponding one of the at least one magnetoresistive element (11, 12, 13, 14) being arranged at a position closest to the conductor section, each of the at least one conductor section (31, 32, 33, 34; 31A, 31B, 32A, 32B, 33A, 33B, 34A, 34B) extends in a curve to protrude in a direction away from the corresponding magnetoresistive element, the magnetic sensor (1; 101) further comprises a support element (40) which carries the at least one magnetoresistive element (11, 12, 13, 14), the support element (40) has an upper surface (40a) opposite the at least one magnetoresistive element (11, 12, 13, 14) and a lower surface (40b) located on a side opposite the upper surface (40a), the upper surface (40a) of the support member (40) has a curved surface portion (40a1) which is curved so as to protrude in a direction away from the lower surface (40b) of the support member (40); and the at least one magnetoresistive element is located on the curved surface portion (40a1).

Description

BACKGROUND OF THE INVENTION 1. Field of the Invention

[0001] The present invention relates to a magnetic sensor comprising a magnetoresistive element and a coil that generates a coil magnetic field applied to the magnetoresistive element. 2. Description of the state of the art

[0002] Magnetic sensors have been used for a wide variety of applications. Examples of well-known magnetic sensors include those that use a magnetoresistive spin-valve element deposited on a substrate. The magnetoresistive spin-valve element contains a layer with fixed magnetization, a free layer with a magnetization whose direction varies depending on the direction of an applied magnetic field, and a gap layer located between the magnetized layer and the free layer.

[0003] In a magnetic sensor using a magnetoresistive element, the magnetoresistive element preferably operates in its linear region. The linear region of the magnetoresistive element refers to a region in which the resistance of the magnetoresistive element changes linearly or substantially linearly with a change in a magnetic field applied to the magnetoresistive element in a map showing a relationship between the applied magnetic field and the resistance of the magnetoresistive element. Examples of known methods for adjusting the operating range of the magnetoresistive element to enable operation in the linear region include imparting uniaxial magnetic anisotropy, such as shape magnetic anisotropy, to the free layer of the magnetoresistive element.

[0004] When a magnetoresistive element includes a free layer with magnetic shape anisotropy, the direction of magnetization of the free layer is set to one of two opposite directions parallel to the free layer easy magnetization axis in the absence of an applied magnetic field. However, the magnetization of the free layer of the magnetoresistive element can be reversed by applying a perturbing magnetic field, etc. For example, a magnetic sensor using the magnetoresistive element may produce a detection value different from the original value once the magnetization of the free layer is reversed. An example of a method for aligning the direction of magnetization of the free layer to an originally set direction in the absence of an applied magnetic field is to apply a magnetic field to the magnetoresistive element from the outside.

[0005] JP 2017 - 72 375 A describes a magnetic sensor in which a magnetoresistive element is integrated with a coil. The coil of the magnetic sensor generates a bias magnetic field that is applied to the free layer of the magnetoresistive element. The bias magnetic field can align the direction of magnetization of the free layer with the direction of the bias magnetic field in the absence of an applied magnetic field. Furthermore, if the direction of magnetization of the free layer deviates from the originally set direction in the absence of an applied magnetic field, the magnetic sensor can generate the bias magnetic field to reset the direction of magnetization of the free layer.

[0006] To align the direction of magnetization of the free layer in the absence of an applied magnetic field, or to reset the direction of magnetization of the free layer by the magnetic field generated by the coil, a sufficient amount of current must be passed through the coil. However, in a magnetic sensor in which a magnetoresistive element is integrated with a coil, such as the magnetic sensor described in JP 2017 - 72 375 A, a sufficient amount of current cannot always be passed through the coil. As a result, there have been cases where a magnetic field of sufficient strength cannot be applied to the free layer. Documents US 2017 / 0 115 363 A1 and US 2013 / 0 320 972 A1 describe other magnetic sensors. SUMMARY OF THE INVENTION

[0007] The object of the present invention is to provide a magnetic sensor which can apply a magnetic field of sufficient strength to a magnetoresistive element by means of a coil.

[0008] A magnetic sensor according to the present invention includes at least one magnetoresistive element whose resistance changes with an external magnetic field, and a coil that generates a coil magnetic field, wherein the coil magnetic field is a magnetic field to be applied to the at least one magnetoresistive element. The coil includes at least one conductor portion. The coil magnetic field comprises a partial magnetic field generated by each of the at least one conductor portions. Each of the at least one conductor portions is located at a position such that the partial magnetic field generated by the conductor portion is applied to one of the at least one magnetoresistive elements corresponding to the conductor portion and extends along an imaginary curve curved to protrude in a direction away from the corresponding magnetoresistive element.

[0009] The magnetic sensor according to the present invention further includes a support member supporting the at least one magnetoresistive element. The support member includes an upper surface facing the at least one magnetoresistive element and a lower surface located on a side opposite the upper surface. The upper surface of the support member has a curved surface portion curved to protrude in a direction away from the lower surface of the support member. The at least one magnetoresistive element is located on the curved surface portion. Each of the at least one magnetoresistive elements also includes a lower surface opposite the support member. The bottom surface of each of the at least one magnetoresistive element may be a curved surface that curves along the curved surface portion.

[0010] When the upper surface of the support member includes the curved surface portion, the curved surface portion may include a central portion extending along a first direction and located at the center of the curved surface portion in a second direction orthogonal to the first direction, and a first side portion and a second side portion located on either side of the central portion in the second direction. In such a case, the first and second side portions may be two curved slopes located at positions closer to the bottom surface of the support member than the central portion, and whose distance from the bottom surface of the support member increases. The at least one magnetoresistive element may be located on the first side portion.Alternatively, the at least one magnetoresistive element may include at least one first magnetoresistive element located on the first side portion and at least one second magnetoresistive element located on the second side portion.

[0011] When the magnetic sensor according to the invention comprises the support element, the at least one conductor section can be arranged at a location where the at least one magnetoresistive element is sandwiched with the support element. In such a case, the magnetic sensor can further comprise an insulating layer covering the at least one magnetoresistive element and the upper surface of the support part. The at least one conductor section can be located on the insulating layer. In such a case, the at least one magnetoresistive element can each also comprise a stack of multiple layers. The at least one conductor section can each extend partially parallel to the surfaces of the layers that form one of the at least one magnetoresistive elements, namely the one corresponding to the conductor section.Alternatively, the at least one conductor section may not extend parallel to surfaces of the layers forming one of the at least one magnetic element corresponding to the conductor section.

[0012] When the at least one conductor portion is located at the location where the at least one magnetoresistive element is sandwiched with the support member, the coil may further include at least one second conductor portion. The at least one second conductor portion is a different part of the coil than the at least one conductor portion. In such a case, the magnetic field of the coil may further include a second partial magnetic field generated by each of the at least one second conductor portion. The at least one second conductor portion may be located on the lower surface side of the support member. The at least one second conductor portion may each be arranged at a position such that the second partial magnetic field generated by the second conductor portion is applied to one of the at least one magnetoresistive elements corresponding to the second conductor portion.

[0013] If the coil includes the at least one second conductor section, the at least one magnetoresistive element may each include a stack of multiple layers. The at least one conductor section may each extend partially parallel to the surfaces of the layers forming one of the at least one magnetoresistive elements, namely the one corresponding to the conductor section. The at least one second conductor section may each extend non-parallel to surfaces of the layers forming one of the at least one magnetoresistive elements, wherein the element corresponding to the second conductor section corresponds to the second conductor section. Alternatively, the at least one conductor section may each extend non-parallel to surfaces of the layers forming one of the at least one magnetoresistive elements corresponding to the conductor section.The at least one second conductor section may each extend partially parallel to the surfaces of the layers forming one of the at least one magnetoresistive element corresponding to the second conductor section.

[0014] In the magnetic sensor of the present invention, the at least one magnetoresistive element may each include a fixed magnetization layer with a first magnetization whose direction is fixed, and a free layer with a second magnetization whose direction is variable with the external magnetic field. The coil magnetic field may be designed to orient the direction of the second magnetization of the free layer in a predetermined direction.

[0015] In the magnetic sensor of the present invention, the at least one conductor portion forming part of the coil is positioned such that the partial magnetic field generated by the conductor portion is applied to one of the at least one magnetoresistive elements corresponding to the conductor portion and extends along an imaginary curve curved to protrude in a direction away from the corresponding magnetoresistive element. Thus, according to the present invention, a magnetic field of sufficient strength can be applied to the magnetoresistive element by the coil.

[0016] Other and further objects, features and advantages of the present invention will be set forth in more detail in the following description. BRIEF DESCRIPTION OF THE DRAWINGS Fig. is an explanatory diagram showing the schematic structure of a magnetic sensor system of a first embodiment of the invention. Fig. is a perspective view showing magnetoresistive elements and a coil of a magnetic sensor according to the first embodiment of the invention. Fig. is a perspective view showing the magnetoresistive elements and the coil of the magnetic sensor according to the first embodiment of the invention. Fig. is a plan view showing a magnetic sensor according to the first embodiment of the invention. Fig. is a sectional view showing a cross section of the magnetic sensor according to the first embodiment of the invention. Fig. is a circuit diagram showing the circuit configuration of the magnetic sensor according to the first embodiment of the invention. Fig. is a perspective view showing the magnetoresistive elements, the lower electrodes and the upper electrodes of the first embodiment of the invention. Fig. is a perspective view showing the magnetoresistive element of the first embodiment of the invention. Fig. is an explanatory diagram for describing a target magnetic field of the first embodiment of the invention. Fig. is an explanatory diagram showing the definition of an angle that the direction of the target magnetic field forms with respect to a reference direction in the first embodiment of the present invention. Fig. is an explanatory diagram for describing the shape of an upper ladder part and a lower ladder part of the first embodiment of the present invention. Fig. is a sectional view showing a cross section of a first modification example of the magnetic sensor according to the first embodiment of the present invention. Fig. is a sectional view showing a cross section of a second modification example of the magnetic sensor according to the first embodiment of the present invention. Fig. is a perspective view showing magnetoresistive elements and a coil of a magnetic sensor according to a second embodiment of the invention. Fig. is a perspective view showing the magnetoresistive elements and the coil of the magnetic sensor according to the second embodiment of the invention. Fig. is a plan view showing the magnetic sensor according to the second embodiment of the invention. Fig. is a sectional view showing a cross section of the magnetic sensor according to the second embodiment of the invention. Fig. is a circuit diagram showing the circuit arrangement of the magnetic sensor according to the second embodiment of the invention. Fig. is an explanatory diagram for describing the shape of an upper ladder part and a lower ladder part of the second embodiment of the present invention. Fig. is an explanatory diagram for describing a target magnetic field for a first magnetoresistive element according to the second embodiment of the present invention. Fig. is an explanatory diagram for describing a target magnetic field for a second magnetoresistive element to be detected according to the second embodiment of the present invention. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS [First Embodiment]

[0017] Preferred embodiments of the present invention will now be described in detail with reference to the drawings. A schematic diagram of a magnetic sensor system including a magnetic sensor according to a first embodiment of the present invention will first be described with reference to Figure 1. A magnetic sensor system 100 according to the present embodiment includes a magnetic sensor 1 according to the present embodiment and a magnetic field generator 5. The magnetic field generator 5 generates a target magnetic field MF, which is a magnetic field to be detected by the magnetic sensor 1 (magnetic field to be detected).

[0018] The magnetic field generator 5 is rotatable about a rotation axis C. The magnetic field generator 5 contains a pair of magnets 6A and 6B. The magnets 6A and 6B are arranged at symmetrical positions, with a virtual plane centered on the rotation axis C. The magnets 6A and 6B each have an N pole and an S pole. The magnets 6A and 6B are aligned such that the N pole of the magnet 6A is opposite the S pole of the magnet 6B. The magnetic field generator 5 generates the target magnetic field MF in the direction from the N pole of the magnet 6A to the S pole of the magnet 6B.

[0019] The magnetic sensor 1 is located at a position where the target magnetic field MF can be detected at a predetermined reference position. The reference position may be located on a rotation axis C. In the following description, the reference position is located on the rotation axis C. The magnetic sensor 1 detects the target magnetic field MF generated by the magnetic field generator 5 and generates a detection value Vs. The detection value Vs corresponds to a relative position, or more specifically, the rotation position, of the magnetic field generator 5 with respect to the magnetic sensor 1.

[0020] The magnetic sensor system 100 can be used as a device for detecting the rotational position of a rotatable, movable part in a device containing the movable part. Examples of such a device include a joint of an industrial robot. Fig. shows an example in which the magnetic sensor system 100 is applied to an industrial robot 200.

[0021] The Fig. The industrial robot 200 shown comprises a movable part 201 and a support unit 202 that rotatably supports the movable part 201. The movable part 201 and the support unit 202 are connected at a joint. The movable part 201 rotates about the rotation axis C. For example, if the magnetic sensor system 100 is attached to the joint of the industrial robot 200, the magnetic sensor 1 can be attached to the support unit 202, and the magnets 6A and 6B can be attached to the movable part 201.

[0022] Now we define the X, Y and Z directions as in Fig. The X, Y and Z directions are orthogonal to each other. In the present embodiment, a direction parallel to the rotation axis C (in Fig. a direction outside the plane of the drawing) is called the X-direction. In Fig. The Y direction is shown as the right direction and the Z direction as the upward direction. The directions opposite to the X, Y, and Z directions are referred to as the -X, -Y, and -Z directions, respectively. The direction of the target magnetic field MF rotates within the YZ plane around the reference position on the rotation axis C.

[0023] Next, a configuration of the magnetic sensor 1 according to the present embodiment will be described with reference to FIG. Fig. described. Fig. is a perspective view showing magnetoresistive elements and a coil of the magnetic sensor 1. Fig. is a plan view showing the magnetic sensor 1. Fig. is a sectional view showing a cross section of the magnetic sensor 1. Fig. is a circuit diagram showing the circuit structure of the magnetic sensor 1.

[0024] The magnetic sensor 1 includes at least one magnetoresistive element whose resistance changes with an external magnetic field, and a support element 40 that supports the at least one magnetoresistive element. A magnetoresistive element is hereinafter referred to as an MR element. Each of the at least one MR elements is configured to be capable of detecting the target magnetic field MF. In the present embodiment, the magnetic sensor 1 includes four MR elements 11, 12, 13, and 14 as the at least one MR element. Fig. shows a cross section of the magnetic sensor 1 intersecting the MR element 11.

[0025] For example, the support element 40 contains an insulating layer of an insulating material, e.g., SiO2. As shown in Fig. As shown, the support 40 includes an upper surface 40a opposite the MR elements 11 to 14 and a lower surface 40b located on a side opposite the upper surface 40a. The upper surface 40a is located at one end of the support member 40 in the Z direction. The lower surface 40b is located at one end of the support member 40 in the -Z direction. The lower surface 40b is parallel to the XY plane.

[0026] The upper surface 40a of the support member 40 includes a curved surface portion 40a1 and a flat surface portion 40a2. The curved surface portion 40a1 is curved to protrude in a direction away from the lower surface 40b of the support member 40 (Z direction). The flat surface portion 40a2 is located at a position closer to the bottom surface 40b than the curved surface portion 40a1. The flat surface portion 40a2 may be parallel to the XY plane.

[0027] A direction parallel to the X direction is referred to as a first direction, and a direction parallel to the Y direction is referred to as a second direction. The first and second directions are each defined to include a specific direction and a direction opposite to the specific direction. The curved surface portion 40a1 includes a central portion C1, a first side portion SD1, and a second side portion SD2. The central portion C1 extends along the first direction and is located at the center of the curved surface portion 40a1 in the second direction. The first and second side portions SD1 and SD2 are located on both sides of the central portion C1 in the second direction. The first and second side portions SD1 and SD2 are located at positions closer to the bottom surface 40b of the support member 40 than the central portion C1.The first and second side portions SD1 and SD2 are two curved slopes whose distance increases toward the bottom surface 40b of the support member 40. The first and second side portions SD1 and SD2 have a symmetrical or substantially symmetrical shape with respect to the XZ plane intersecting the center of the curved surface portion 40a1 in the second direction.

[0028] The support member 40 has a cross-sectional shape such that the curved surface portion 40a1 is formed on the upper surface 40a. Specifically, the support member 40 has a cross-sectional shape that bulges in the Z direction in a given cross section parallel to the YZ plane.

[0029] The MR elements 11 to 14 are located on the curved surface portion 40a1. Specifically, in the present embodiment, the MR elements 11 to 14 are all located on the first side part SD1 of the curved surface part 40a1. Lower electrodes, which will be described later, are arranged between the MR elements 11 to 14 and the support member 40. As shown in FIGS. Fig. As shown, the MR elements 11 to 14 are arranged in a row in this order along the -X direction.

[0030] The MR elements 11 to 14 each have a bottom surface opposite the support part 40. The bottom surfaces of the MR elements 11 to 14 are curved surfaces that are curved along the curved surface part 40a1.

[0031] As described later, the MR elements 11 to 14 each comprise a stack of multiple layers. Assuming that the layers have flat surfaces, the MR elements 11 to 14 are each arranged on the first side part SD1 in such an orientation that the surfaces of the layers are inclined to the XY plane.

[0032] The magnetic sensor 1 further includes a coil 30 that generates a coil magnetic field, which is a magnetic field applied to the at least one MR element, ie, the MR elements 11 to 14. The MR elements 11 to 14 are integrated into the coil 30.

[0033] The coil 30 includes a first end 30a and a second end 30b located at both longitudinal ends of the conductor forming the coil 30. The first and second ends 30a and 30b are connected to a power supply (not shown). The coil 30 is wound around the MR elements 11 to 14. Specifically, in the present embodiment, the coil 30 is wound such that a coil magnetic field in the X or -X direction is applied to each of the MR elements 11 to 14. For example, when a current flows in one direction from the first end 30a to the second end 30b, a coil magnetic field in the -X direction is applied to the MR elements 11 and 13, and a coil magnetic field in the X direction is applied to the MR elements 12 and 14. When a current is passed in one direction from the second end 30b to the first end 30a, a coil magnetic field in the X direction is applied to the MR elements 11 and 13 and a coil magnetic field in the -X direction is applied to the MR elements 12 and 14.

[0034] The coil 30 includes upper coil portions 30U arranged on the Z-direction side with respect to the bottom surface 40b of the support member 40, and lower coil portions 30L arranged on the -Z-direction side with respect to the bottom surface 40b of the support member 40. In the Fig. The upper winding parts 30U are shown by double dashed lines. In Fig. the lower coil parts 30L are shown by dashed lines.

[0035] The magnetic sensor 1 further includes a plurality of lower electrodes 41 and a plurality of upper electrodes 42 that electrically connect the MR elements 11 to 14, a substrate 61, and insulating layers 62, 63, 64, 65, 66, and 67. The insulating layer 62 is located on the substrate 61. The lower coil sections 30L include a plurality of first layers 30L1 located on the insulating layer 62 and a plurality of second layers 30L2 located on the plurality of first layers 30L1. The insulating layer 63 is located on the insulating layer 62, around the plurality of first layers 30L1. The insulating layer 64 is located on the first layers 30L1, and the insulating layer 63 is located around the second layers 30L2. The support 40 is located on the second layers 30L2 and the insulating layer 64.

[0036] The plurality of lower electrodes 41 are located on the upper surface 40a of the support part 40. The plurality of lower electrodes 41 on the upper surface 40a of the support member 40 are mainly located on the first side part SD1 of the curved surface part 40a1. The insulating layer 65 is located on the upper surface 40a of the support member 40, around the plurality of lower electrodes 41. The MR elements 11 to 14 are located on the plurality of lower electrodes 41. The insulating layer 66 is located on the plurality of lower electrodes 41, and the insulating layer 65 is located around the MR elements 11 to 14. The plurality of upper electrodes 42 are located on the MR elements 11 to 14 and the insulating layer 66. The insulating layer 67 is located on the plurality of upper electrodes 42 and the insulating layer 66. Fig. the majority of lower electrodes 41, the majority of upper electrodes 42 and the insulating layers 65 to 67 are omitted.

[0037] The upper coil parts 30U are mainly located on the insulating layer 67. The magnetic sensor 1 has a plurality of through holes extending from the upper surface of the insulating layer 67 to the lower surface 40b of the support part 40. The upper coil parts 30U and the lower coil parts 30L are connected to each other via the plurality of through holes.

[0038] The majority of the lower electrodes 41 and the majority of the upper electrodes 42 are made of a conductive material such as Cu. The substrate 61 is a semiconductor substrate made of a semiconductor such as Si. The insulating layers 62 to 67 are made of an insulating material such as SiO2.

[0039] The magnetic sensor 1 further includes an insulating layer (not shown) covering the upper coil portions 30U and the insulating layer 67. The insulating layer (not shown) is made of an insulating material such as SiO2.

[0040] Note that the second layers 30L2 of the lower coil parts 30L and the insulating layer 64 may be omitted. In such a case, the support part 40 is located on the first layers 30L1 of the lower coil parts 30L and the insulating layer 63.

[0041] As in Fig. As shown, the magnetic sensor 1 further includes a power supply node V1, a ground node G1, two signal output nodes E11 and E12, and a differential detector 21. The MR element 11 is arranged between the power supply node V1 and the signal output node E11. The MR element 12 is arranged between the signal output node E11 and the ground node G1. The MR element 13 is arranged between the signal output node E12 and the ground node G1. The MR element 14 is arranged between the power supply node V1 and the signal output node E12. A predetermined magnitude of the supply voltage is applied to the supply node V1. The ground node G1 is grounded. The differential detector 21 outputs a signal corresponding to a potential difference between the signal output nodes E11 and E12 as the first detection signal S1.

[0042] The magnetic sensor 1 further includes a detection value generation circuit 22 that generates the detection value Vs based on the detection signal S1. The detection value Vs depends on the detection signal S1. The detection value generation circuit 22 includes, for example, an application-specific integrated circuit (ASIC) or a microcomputer. A method for generating the detection value Vs will be described later.

[0043] The configuration of MR elements 11 to 14 will now be described in detail. When describing one of the MR elements 11 to 14, the MR element will be referred to by the reference number 10. Fig. is a perspective view showing the MR elements 10, the lower electrodes 41 and the upper electrodes 42. Fig. is a perspective view showing the MR element 10.

[0044] In particular, in the present embodiment, the MR element 10 is a spin valve MR element. As shown in Fig. As shown in Figure 8, the MR element 10 includes a magnetization pin layer 52 having a magnetization direction fixed, a free layer 54 having a magnetization direction variable depending on the direction of an external magnetic field, and a gap layer. The MR element 10 may be a tunneling magnetoresistive (TMR) element or a giant magnetoresistive (GMR) element. In the TMR element, the gap layer 53 is a tunnel barrier layer. In the GMR element, the gap layer 53 is a non-magnetic conductive layer. The resistance of the MR element 10 changes with an angle formed by the magnetization direction of the free layer 54 with respect to the magnetization direction of the magnetization pin layer 52. The resistance is minimized when the angle is 0°. The resistance is maximized when the angle is 180°.In the MR element 10, the free layer 54 has a shape anisotropy that adjusts the direction of the magnetization easy axis to be orthogonal to the magnetization direction of the magnetization pinning layer 52.

[0045] Each of the lower electrodes 41 has a long, slender shape. Two lower electrodes 41, which are adjacent to each other in the longitudinal direction of the lower electrodes 41, have a gap between them. As shown in Fig. As shown, the MR element 10 is located on top of the lower electrode 41 near one end in the longitudinal direction. As shown in Fig. As shown, the MR element 10 further includes an antiferromagnetic layer 51. The antiferromagnetic layer 51, the magnetizable pinning layer 52, the gap layer 53, and the free layer 54 are stacked in this order from the bottom electrode 41, from the nearest to the farthest. The antiferromagnetic layer 51 is electrically connected to the bottom electrode 41. The antiferromagnetic layer 51 is made of an antiferromagnetic material. The antiferromagnetic layer 51 is in exchange coupling with the magnetization pin-shaped layer 52 to determine the magnetization direction of the magnetization pin-shaped layer 52.

[0046] Each of the upper electrodes 42 has a long, slender shape and establishes an electrical connection between the respective free layers 54 of two adjacent MR elements 10 arranged on two lower electrodes 41 adjacent in the longitudinal direction of the lower electrodes 41. It should be noted that the layers 51 to 54 of the MR element 10 are arranged in the reverse order as in Fig. can be stacked.

[0047] Next, a method for generating the detection value Vs will be described. Assuming that the surfaces of the layers constituting the MR elements 10 are flat surfaces, a direction parallel to the surfaces of the layers and orthogonal to the X direction is referred to as the U direction. The direction opposite to the U direction is referred to as the -U direction. Assuming that the surfaces of the layers are flat surfaces as described above, the MR elements 10 on the first side portion SD1 are arranged in such an orientation that the surfaces of the layers are oblique to the XY plane. This makes the U direction different from the Y or -Y direction. In the present embodiment, the U direction is a direction rotated from the -Y direction toward the Z direction by α, an angle greater than 0° and less than 90°.

[0048] Fig. is an explanatory diagram describing the target magnetic field MF. In Fig. The position at which the MR element 10 detects the target magnetic field MF is indicated by the symbol P1. In the present embodiment, the direction and strength of the target magnetic field MF at the position P1 are the same as those of the target magnetic field MF at the reference position on the rotation axis C (see Fig. ). The direction of the target magnetic field MF at position P1 rotates around position P1.

[0049] In Fig. An imaginary straight line passing through position P1 and parallel to the Y direction is denoted by the symbol LY. An imaginary straight line passing through position P1 and parallel to the Z direction is denoted by the symbol LZ. An imaginary straight line passing through position P1 and parallel to the U direction is denoted by the symbol LU. The target magnetic field MF at position P1 can be divided into a component MF1 in a direction parallel to the U direction and a component MF2 in a direction parallel to a direction perpendicular to the U direction.

[0050] Fig. is an explanatory diagram showing the definition of an angle that the direction of the target magnetic field MF forms with respect to a reference direction. In the present embodiment, the reference direction is the U direction. The angle that the direction of the target magnetic field MF at the position P1 forms with respect to the reference direction, i.e., the U direction, is represented by the symbol θ. The angle θ is expressed in positive values ​​when viewed clockwise from the U direction (see Fig. ). The angle θ is expressed in negative values ​​when viewed counterclockwise from the U-direction ( Fig. ).

[0051] The direction of component MF1 is the U direction when the angle falls within the range of greater than or equal to 0° and less than 90° or within the range of greater than 270° and less than or equal to 360°. The direction of component MF1 is the -U direction when the angle θ falls within the range of greater than 90° and less than 270°. In the following, the strength of component MF1 is expressed in positive values ​​when the direction of component MF1 is the U direction. The strength of component MF1 is expressed in negative values ​​when the direction of component MF1 is the -U direction.

[0052] In the magnetic sensor 1, the directions of magnetization of the magnetization pin layers 52 in the MR elements 11 to 14 and the shape anisotropy of the free layers 54 in the MR elements 11 to 14 are adjusted so that the strength of the component MF1 of the target magnetic field MF at the position P1 can be detected. Fig. 6, the thick arrow indicates the direction of magnetization in the magnetized layer 52. The X and U directions are shown in Fig. 6. As shown in Fig. As shown in Figure 6, the magnetization directions in the magnetization-pinned layers 52 in the MR elements 11 and 13 are in the U direction. The magnetization directions in the magnetization pin layers 52 in the MR elements 12 and 14 are in the -U direction. The free layer 54 exhibits shape anisotropy, so the direction of the easy axis of magnetization is parallel to the X direction.

[0053] When the strength of component MF1 is 0, i.e., the direction of the target magnetic field MF is orthogonal to the U direction, the magnetization directions in the free layers 54 are the X or -X direction. When the strength of component MF1 has a positive value, the magnetization directions in the free layers 54 incline from the X or -X direction to the U direction. As a result, the resistances of MR elements 11 and 13 decrease, and the resistances of MR elements 12 and 14 increase, compared to when the strength of component MF1 is 0. Conversely, when the strength of component MF1 has a negative value, the resistances of MR elements 11 and 13 increase, and the resistances of MR elements 12 and 14 decrease, compared to when the strength of component MF1 is 0.

[0054] A change in the strength of component MF1 causes the resistance values ​​of MR elements 11 to 14 to change such that the resistance values ​​of MR elements 11 and 13 increase while the resistance values ​​of MR elements 12 and 14 decrease, or such that the resistance values ​​of MR elements 11 and 13 decrease while the resistance values ​​of MR elements 12 and 14 increase. This causes a change in the potential difference between signal output nodes E11 and E12. Difference detector 21 outputs a signal as detection signal S1 that corresponds to a potential difference between signal output nodes E11 and E12. Detection signal S1 corresponds to the strength of component MF1. The strength of component MF1 corresponds to the direction of the target magnetic field MF. The direction of the target magnetic field MF corresponds to a relative position, or in particular a rotational position, of the magnetic field generator 5 with respect to the magnetic sensor 1.The detection signal S1 therefore has a correspondence with the rotational position.

[0055] The detection value generation circuit 22 generates the detection value Vs based on the detection signal S1. The detection value generation circuit 22 can generate a value indicating the strength of the component MF1 as the detection value Vs. The value indicating the strength of the component MF1 can be generated, for example, by dividing the value of the detection signal S1 by the ratio of a change in the detection signal S1 to a change in the strength of the component MF1.

[0056] Alternatively, the detection value generation circuit 22 may generate a value indicating the angle θ formed by the direction of the target magnetic field MF at the position P1 with respect to the U direction as the detection value Vs in the range of greater than or equal to 0° and less than 180°. In such a case, the detection value generation circuit 22 first generates a normalization signal S1c. The normalization signal S1c is a signal generated by normalizing the detection signal S1 so that the detection signal S1 has a value of 1 when the angle θ is 0° and a value of -1 when the angle θ is 180°. The detection value generation circuit 22 then generates the detection value Vs using the normalization signal S1c by the following Equation (1): Vs=acos(S1c) “acos” stands for arccosine.

[0057] As described above, in the present embodiment, the direction and strength of the target magnetic field MF at position P1 are consistent with those of the target magnetic field MF at the reference position. Thus, the strength of the component MF1 can be regarded as the strength of the component of the target magnetic field MF at the reference position in the direction parallel to the U direction. The angle θ formed by the direction of the target magnetic field MF at position P1 with respect to the U direction can be regarded as the angle formed by the direction of the target magnetic field MF at the reference position with respect to the U direction.

[0058] In each of the cases in which the value indicative of the strength of the component MF1 is generated as the detection value Vs and in which the value indicative of the angle θ is generated as the detection value Vs, the detection value Vs has a correspondence with the relative position, or in particular the rotational position, of the magnetic field generator 5 with respect to the magnetic sensor 1.

[0059] Next, the configuration of coil 30 will be described in more detail. Coil 30 includes at least one conductor section. The magnetic field of the coil comprises a partial magnetic field generated by each of the at least one conductor section.

[0060] The at least one conductor section is located at a position such that the partial magnetic field generated by the conductor section is applied to one of the at least one MR elements corresponding to the conductor section. In the present embodiment, the coil 30 includes four conductor sections 31, 32, 33, and 34 as the at least one conductor section. The conductor section 31 corresponds to the MR element 11 and is located at a position such that the partial magnetic field generated by the conductor section 31 is applied to the MR element 11. The conductor section 32 corresponds to the MR element 12 and is located at a position such that the partial magnetic field generated by the conductor section 32 is applied to the MR element 12. The conductor section 33 corresponds to the MR element 13 and is located at a position such that the partial magnetic field generated by the conductor section 33 is applied to the MR element 13.The conductor section 34 corresponds to the MR element 14 and is located at such a position that the partial magnetic field generated by the conductor section 34 is applied to the MR element 14.

[0061] In particular, in the present embodiment, all the conductor sections 31 to 34 are part of the upper coil sections 30U. The conductor sections 31 to 34 are hereinafter referred to as upper conductor sections 31 to 34. For ease of understanding, the upper conductor sections 31 to 34 are Fig. 2 shown hatched. The upper conductor sections 31 to 34 are all located on the insulating layer 67 (see Fig. 5). The insulating layer 67 covers the MR elements 11 to 14 and the upper surface 40a of the support member 40.

[0062] The upper conductor portion 31 is located at a position where the MR element 11 is sandwiched with the support portion 40. The upper conductor portion 32 is located at a position where the MR element 12 can be sandwiched with the support member 40. The upper conductor portion 33 is located at a position where the MR element 13 can be sandwiched with the support member 40. The upper conductor portion 34 is located at a position where the MR element 14 can be sandwiched with the support member 40.

[0063] The coil 30 further includes the lower conductor sections 35, 36, 37 and 38. The lower conductor sections 35 to 38 are different parts of the coil 30 than the upper conductor sections 31 to 34. In particular, in the present embodiment, all the lower conductor sections 35 to 38 are part of the lower coil sections 30L, which are located on the underside 40b of the support part 40. For better understanding, the lower conductor parts 35 to 38 are in Fig. shown hatched. The lower conductor sections 35 to 38 correspond to the "at least one second conductor section" according to the present invention.

[0064] The coil magnetic field further includes partial magnetic fields generated by the respective lower conductor sections 35 to 38. The partial magnetic fields generated by the respective lower conductor sections 35 to 38 correspond to the "second partial magnetic field" according to the present invention.

[0065] The lower conductor portion 35 corresponds to the MR element 11 and is located at a position such that the partial magnetic field generated by the lower conductor portion 35 is applied to the MR element 11. The lower conductor portion 36 corresponds to the MR element 12 and is located at a position such that the partial magnetic field generated by the lower conductor portion 36 is applied to the MR element 12. The lower conductor portion 37 corresponds to the MR element 13 and is located at a position such that the partial magnetic field generated by the lower conductor portion 37 is applied to the MR element 13. The lower conductor portion 38 corresponds to the MR element 14 and is located at a position such that the partial magnetic field generated by the lower conductor portion 38 is applied to the MR element 14.

[0066] The lower conductor portion 35 is located at a position where the support member 40 can be sandwiched with the MR element 11. The lower conductor portion 36 is located at a position where the support member 40 can be sandwiched with the MR element 12. The lower conductor portion 37 is located at a position where the support member 40 can be sandwiched with the MR element 13. The lower conductor portion 38 is located at a position where the support member 40 can be sandwiched with the MR element 14.

[0067] Now, the shape of the upper conductor sections 31 to 34 and the lower conductor sections 35 to 38 will be described with reference to Fig. described. Fig. is an explanatory diagram for describing the shape of the upper conductor part 31 and the lower conductor part 35. In Fig. the boundaries between the upper conductor part 31 and the other parts of the upper coil part 30U are shown by dashed lines. In Fig. the boundaries between the lower conductor part 35 and the other parts of the lower coil part 30L are shown by dashed lines.

[0068] The upper conductor part 31 extends along an imaginary curve L which is curved so that it projects in a direction away from the MR element 11. In Fig. the imaginary curve L is represented by a double-dashed dashed line, which is denoted by the symbol L. The imaginary curve L is a curve parallel to the YZ plane. In the Fig. In the example shown, the direction away from the MR element 11 specifically refers to a direction inclined from the Z direction to the Y direction by a predetermined angle greater than 0° and less than 90°. Viewed from the MR element 11, the imaginary curve L bends to protrude in this direction. A portion of the upper conductor section 31 is parallel to the surfaces of the layers constituting the MR element 11.

[0069] The lower conductor section 35 extends along the Y direction. The lower conductor part 35 does not extend parallel to the surfaces of the layers forming the MR element 11.

[0070] Similarly, the upper conductor portion 32 extends along an imaginary curve curved to protrude in a direction away from the MR element 12. A portion of the upper conductor portion 32 extends parallel to the surfaces of the layers that form the MR element 12. Similarly, the upper conductor portion 33 extends along an imaginary curve curved to protrude in a direction away from the MR element 13. A portion of the upper conductor portion 33 extends parallel to the surfaces of the layers that form the MR element 13. Similarly, the upper conductor portion 34 extends along an imaginary curve curved to protrude in a direction away from the MR element 14. A portion of the upper conductor portion 34 extends parallel to the surfaces of the layers that form the MR element 14. All imaginary curves are parallel to the YZ plane.

[0071] Similarly, all lower conductor sections 36 to 38 extend along the Y direction. The lower conductor section 36 is not parallel to the surfaces of the layers that make up the MR element 12. The lower conductor section 37 is not parallel to the surfaces of the layers that make up the MR element 13. The lower conductor section 38 is not parallel to the surfaces of the layers that make up the MR element 14.

[0072] The function and effect of the magnetic sensor 1 according to the present embodiment will now be described. In the present embodiment, the upper conductor portions 31 to 34 of the coil 30 are each located at a position such that the partial magnetic field generated by the conductor portion is applied to the MR element 10 corresponding to the conductor portion. Furthermore, the upper conductor portions 31 to 34 each extend along an imaginary curve curved so as to protrude in a direction away from the corresponding MR element 10. According to the present embodiment, the coil 30 can thus apply a magnetic field of sufficient strength to the MR elements 10. This effect will now be described using the combination of the upper conductor portion 31 and the MR element 11 as an example.

[0073] In Fig. A plurality of dashed lines overlapping the MR element 11 and the upper coil portion 30U represent the magnetic lines of force corresponding to the partial magnetic field generated by the upper conductor portion 31. The partial magnetic field is generated around the axis of the center line of the upper conductor portion 31, which extends in the extending direction of the upper conductor portion 31. Like the imaginary curve L, the center line of the upper conductor portion 31 is a curve curved so as to protrude in the direction away from the MR element 11. Since the center line of the upper conductor portion 31 is such a curve, the partial magnetic field generated near the two longitudinal ends of the upper conductor portion 31 inclines toward the MR element 11. As shown in Fig. As shown, this allows the plurality of magnetic lines of force corresponding to the partial magnetic field generated by the upper conductor part 31 to be concentrated on the MR element 11. This increases the strength of the partial magnetic field applied to the MR element 11 compared with the case where the center line of the upper conductor part 31 is a straight line or a curve curved to protrude in a direction toward the MR element 11, when a comparison is made assuming that the center position in the extension direction of the upper conductor part 31 is the same.

[0074] The above description of the combination of the upper conductor part 31 and the MR element 11 also applies to the combination of the upper conductor part 32 and the MR element 12, the combination of the upper conductor part 33 and the MR element 13, and the combination of the upper conductor part 34 and the MR element 14. According to the present embodiment, the coil 30 can thus apply a magnetic field of sufficient strength to the MR elements 10.

[0075] According to the present embodiment, the strength of the partial magnetic fields applied to the MR elements 10 can be increased as described above. Thus, the coil 30 can apply a magnetic field of sufficient strength to the MR elements 10 even when the magnitude of the current flowing through the coil 30 is limited by the limitations of the magnetic sensor system 100, such as when the measurement value generation circuit 22 and the coil 30 share a common power supply.

[0076] In the present embodiment, the upper surface 40a of the support member 40 supporting the MR elements 10 includes the curved surface portion 40a1. The curved surface portion 40a1 is curved so as to protrude in the direction away from the lower surface 40b of the support member 40. The curved surface portion 40a1 having such a shape can be formed, for example, by depositing the insulating layer constituting the support member 40 such that the thickness of the insulating layer differs at a plurality of different positions in the second direction. Furthermore, the magnetic sensor 1 includes the insulating layers 65 to 67 covering the MR elements 10 and the upper surface 40a of the support member 40. The upper conductor portions 31 to 34 are located on the insulating layer 67. According to the present embodiment, the insulating layers 65 to 67 are each formed along the curved surface part 40a1.The upper conductor sections 31 to 34 can thereby be shaped to extend along the curved surface section 40a1. The imaginary curves along which the respective upper conductor sections 31 to 34 curve thus curve along the curved surface section 40a1.

[0077] In the present embodiment, the coil 30 further comprises the lower conductor sections 35 to 38. In Fig. a plurality of dashed lines overlapping the MR element 11 and the lower coil part 30L represent the magnetic lines of force corresponding to the partial magnetic field generated by the lower conductor part 35. As shown in Fig. As shown, the partial magnetic field generated by the lower conductor part 35 is applied to the MR element 11. According to the present embodiment, this can further increase the strength of the partial magnetic field applied to the MR element 11. The above description of the combination of the lower conductor part 35 and the MR element 11 also applies to the combination of the lower conductor part 36 and the MR element 12, the combination of the lower conductor part 37 and the MR element 13, and the combination of the lower conductor part 38 and the MR element 14. Thus, according to the present embodiment, a magnetic field of even higher strength can be applied to the MR elements 10 by the coil 30.

[0078] Incidentally, in the present embodiment, the coil magnetic field generated by the coil 30 is used to align the magnetization directions of the free layers 54 in the MR elements 10 to a predetermined direction, that is, the X or -X direction. The coil magnetic field can be temporarily applied to the MR elements 10. According to the present embodiment, the magnetization directions of the free layers 54 can thereby be aligned to a predetermined direction when starting use of the magnetic sensor 1. [Modification examples]

[0079] A description will now be given of the first and second modification examples of the magnetic sensor 1 according to the present embodiment. First, a first modification example of the magnetic sensor 1 will be described. Fig. 1 is a sectional view showing a cross section of the first modification example of the magnetic sensor 1. In the first modification example, the upper surface 40a of the support member 40 does not include the curved surface portion 40a1, but is a flat surface parallel to the XY plane.

[0080] In the first modification example, the MR elements 10 are located on the upper surface 40a of the support beam 40. The lower electrodes 41 are located between the MR elements 10 and the beam 40. The lower surfaces of the MR elements 10 and the surfaces of the layers composing the MR elements 10 are flat surfaces parallel to the XY plane.

[0081] In the first modification example, the insulating layer 67 has an upper surface located at one end in the Z direction. The upper surface includes a curved surface portion. The curved surface portion has the same shape as the curved surface portion 40a1 of the upper surface 40a of the support member 40 shown in FIG. 5. The insulating layer 67 has a shape such that the curved surface portion is formed on the upper surface. Specifically, the insulating layer 67 has a bulge shape in the Z direction in a given cross section parallel to the YZ plane.

[0082] In the first modification example, the upper conductor portions 31 to 34 and the lower conductor portions 35 to 38 of the coil 30 have the same shapes as in the embodiment shown in the Fig. 1 and Fig. 2. The upper conductor sections 31 to 34 of the coil 30 therefore do not extend parallel to the surfaces of the layers constituting the MR elements 11 to 14. On the other hand, the lower conductor sections 35 to 38 of the coil 30 extend partially parallel to the surfaces of the layers constituting the MR elements 11 to 14.

[0083] Next, a second modification example of the magnetic sensor 1 will be described with reference to Fig. described. Fig. 1 is a sectional view showing a cross section of the second modification example of the magnetic sensor 1. The second modification example differs from the first modification example in the following points. In the second modification example, the upper surface of the insulating layer 67 includes a periodically curved surface portion that curves periodically. The upper coil portions 30U of the coil 30 have a meandering shape along the periodically curved surface portion. Note that the upper conductor portions 31 to 34, which are part of the upper coil portions 30U, each meet the requirement of extending along an imaginary curve curvature to protrude in a direction away from the corresponding MR element 10. [Second embodiment]

[0084] A second embodiment of the invention will now be described. First, a configuration of a magnetic sensor according to the present embodiment will be described with reference to Figures 14 to 18. Figures 14 and 15 are perspective views showing magnetoresistive elements and a coil of the magnetic sensor according to the present embodiment, respectively. Fig. is a plan view showing the magnetic sensor according to the present embodiment. Fig. is a sectional view showing a cross section of the magnetic sensor according to the present embodiment. Fig. is a circuit diagram showing the circuit arrangement of the magnetic sensor according to the present embodiment.

[0085] A magnetic sensor 101 according to the present embodiment differs from the magnetic sensor 1 according to the first embodiment in the following points. The magnetic sensor 101 includes the four MR elements 15, 16, 17, and 18 as at least one MR element in addition to the MR elements 11 to 14 according to the first embodiment. The MR elements 15 to 18 are located, together with the MR elements 11 to 14, on the curved surface portion 40a1 of the upper surface 40a of the support member 40. Specifically, all of the MR elements 15 to 18 are located on the second side part SD2 of the curved surface part 40a1. Lower electrodes, which will be described later, are arranged between the MR elements 15 to 18 and the support member 40.

[0086] As in Fig. As shown, the MR elements 15 to 18 are arranged in a row in this order along the -X direction at positions ahead of the MR elements 11 to 14 in the -Y direction. As described in the first embodiment, the second direction is a direction parallel to the Y direction. The MR elements 11 and 15 are located at positions symmetrical or substantially symmetrical to an XZ plane intersecting the center of the curved surface portion \40a1 in the second direction. Similarly, the MR elements 12 and 16 are arranged at positions symmetrical or substantially symmetrical to the XZ plane. Similarly, the MR elements 13 and 17 are arranged at positions symmetrical or substantially symmetrical to the XZ plane. Similarly, the MR elements 14 and 18 are arranged at positions that are symmetric or substantially symmetric to the XZ plane.

[0087] The MR elements 15 to 18 each have the same configuration as that of the MR elements 11 to 14. Specifically, the MR elements 15 to 18 each include a stack of multiple layers. Assuming that the surfaces of the layers are flat surfaces, the MR elements 15 to 18 are each located on the second side part SD2 in such an orientation that the surfaces of the layers are inclined to the XY plane. The MR elements 15 to 18 each have a bottom surface opposite the support element 40. The bottom surfaces of the MR elements 15 to 18 are curved surfaces curved along the curved surface part 40a1.

[0088] The magnetic sensor 101 according to the present embodiment includes a plurality of lower electrodes 41A, a plurality of lower electrodes 41B, a plurality of upper electrodes 42A, and a plurality of upper electrodes 42B instead of the plurality of lower electrodes 41 and the plurality of upper electrodes 42 according to the first embodiment. For example, the electrodes 41A, 41B, 42A, and 42B are made of the same material as the electrodes 41 and 42 according to the first embodiment. The plurality of lower electrodes 41A and the plurality of upper electrodes 42A electrically connect the MR elements 11 to 14 to each other. The shape and arrangement of the plurality of lower electrodes 41A and the plurality of upper electrodes 42A are the same as those of the plurality of lower electrodes 41 and the plurality of upper electrodes 42 according to the first embodiment.

[0089] The plurality of lower electrodes 41B and the plurality of upper electrodes 42B electrically connect the MR elements 15 to 18 to each other. The plurality of lower electrodes 41B are located on the upper surface 40a of the support member 40. The plurality of lower electrodes 41B on the upper surface 40a of the support member 40 are mainly located on the second side part SD2 of the curved surface part 40a1. The MR elements 15 to 18 are located on the plurality of lower electrodes 41B.

[0090] In the present embodiment, the insulating layer 65 is located on the upper surface 40a of the support member 40, around the plurality of lower electrodes 41A and the plurality of lower electrodes 41B. The insulating layer 66 is located on the plurality of lower electrodes 41A, the plurality of lower electrodes 41B, and the insulating layer 65, around the MR elements 11 to 18. The plurality of upper electrodes 42A are located on the MR elements 11 to 14 and the insulating layer 66. The plurality of upper electrodes 42B are located on the MR elements 15 to 18 and the insulating layer 66. The insulating layer 67 is located on the plurality of upper electrodes 42A, the plurality of upper electrodes 42B, and the insulating layer 66. In Fig. the plurality of lower electrodes 41A, the plurality of lower electrodes 41B, the plurality of upper electrodes 42A, the plurality of upper electrodes 42B and the insulating layers 65 to 67 are omitted.

[0091] In the present embodiment, the MR elements 11 to 18 are integrated with the coil 30. The coil 30 is wound around the MR elements 11 to 18. Specifically, in the present embodiment, the coil 30 is wound such that a coil magnetic field in the X or -X direction is applied to each of the MR elements 11 to 18. For example, when a current flows in a direction from the first end 30a of the coil 30 to the second end 30b of the coil 30, a coil magnetic field in the -X direction is applied to the MR elements 11, 13, 15, and 17, and a coil magnetic field in the X direction is applied to the MR elements 12, 14, 16, and 18. Fig. the upper coil parts 30U of the coil 30 are shown by double dashed lines. In Fig. the lower coil parts 30L of the coil 30 are shown by dashed lines.

[0092] As in Fig. As shown, the magnetic sensor 101 according to the present embodiment further includes a power supply node V2, two signal output nodes E21 and E22, and a differential detector 23. The MR element 15 is arranged between the power supply node V2 and the signal output node E21. The MR element 16 is arranged between the signal output node E21 and the ground node G1. The MR element 17 is arranged between the signal output node E22 and the ground node G1. The MR element 18 is arranged between the power supply node V2 and the signal output node E22. The power supply node V2, like the power supply node V1, is supplied with a predetermined magnitude of the supply voltage. The differential detector 23 outputs a signal corresponding to a potential difference between the signal output nodes E21 and E22 as a detection signal S2.

[0093] In the present embodiment, the detection value generation circuit 22 generates a detection value Vs based on the detection signal S1 output from the differential detector 21 and the detection signal S2 output from the differential detector 23. A method for generating the detection value Vs of the present embodiment will be described later.

[0094] In the present embodiment, the coil 30 includes eight upper conductor portions 31A, 32A, 33A, 34A, 31B, 32B, 33B, and 34B and eight lower conductor portions 35A, 36A, 37A, 38A, 35B, 36B, 37B, and 38B instead of the upper conductor portions 31 to 34 and the lower conductor portions 35 to 38 according to the first embodiment.

[0095] The upper conductor sections 31A to 34A and 31B to 34B correspond to the "at least one conductor section" according to the present invention. All upper conductor sections 31A to 34A and 31B to 34B are part of the upper coil sections 30U. For better understanding, the upper conductor sections 31A to 34A and 31B to 34B are Fig. shown hatched. The upper conductor sections 31A to 34A and 31B to 34B are all located on the insulating layer 67.

[0096] The lower conductor sections 35A to 38A and 35B to 38B correspond to the "at least one second conductor section" according to the present invention. The lower conductor sections 35A to 38A and 35B to 38B are a different part of the coil 30 than the upper conductor sections 31A to 34A and 31B to 34B. In particular, in the present embodiment, all of the lower conductor sections 35A to 38A and 35B to 38B are part of the lower coil sections 30L located on the underside 40b of the support part 40. For better understanding, the lower conductor sections 35A to 38A and 35B to 38B in Fig. shown hatched.

[0097] The shape and arrangement of the upper conductor sections 31A to 34A and the lower conductor sections 35A to 38A correspond to the shape and arrangement of the upper conductor sections 31 to 34 and the lower conductor sections 35 to 38 according to the first embodiment.

[0098] The upper conductor part 31B corresponds to the MR element 15 and is located at a position such that the partial magnetic field generated by the upper conductor part 31B is applied to the MR element 15. The upper conductor part 32B corresponds to the MR element 16 and is located at a location such that the partial magnetic field generated by the upper conductor part 32B is applied to the MR element 16. The upper conductor part 33B corresponds to the MR element 17 and is located at a position such that the partial magnetic field generated by the upper conductor part 33B is applied to the MR element 17. The upper conductor part 34B corresponds to the MR element 18 and is located at a position such that the partial magnetic field generated by the upper conductor part 34B is applied to the MR element 18.

[0099] The upper conductor portion 31B is located at a position where the MR element 15 is sandwiched with the support portion 40. The upper conductor portion 32B is located at a position where the MR element 16 can be sandwiched with the support member 40. The upper conductor portion 33B is located at a position where the MR element 17 is sandwiched with the support member 40. The upper conductor portion 34B is located at a position where the MR element 18 is sandwiched with the support member 40.

[0100] The lower conductor portion 35B corresponds to the MR element 15 and is located at a position such that the partial magnetic field generated by the lower conductor portion 35B acts on the MR element 15. The lower conductor portion 36B corresponds to the MR element 16 and is located at a position such that the partial magnetic field generated by the lower conductor portion 36B is applied to the MR element 16. The lower conductor portion 37B corresponds to the MR element 17 and is located at a position such that the partial magnetic field generated by the lower conductor portion 37B is applied to the MR element 17. The lower conductor portion 38B corresponds to the MR element 18 and is located at a position such that the partial magnetic field generated by the lower conductor portion 38B is applied to the MR element 18.

[0101] The lower conductor portion 35B is located at a position where the support member 40 is sandwiched with the MR element 15. The lower conductor portion 36B is located at a position where the support member 40 can be sandwiched with the MR element 16. The lower conductor portion 37B is located at a position where the support member 40 is sandwiched with the MR element 17. The lower conductor portion 38B is located at a position where the support member 40 can be sandwiched with the MR element 18.

[0102] Fig. is an explanatory diagram for describing the shape of the upper conductor part 31B and the lower conductor part 35B. In Fig. The boundaries between the upper conductor part 31B and the other parts of the upper coil part 30U are shown by dashed lines. Fig. the boundaries between the lower conductor part 35B and the other parts of the lower coil part 30L are shown by dashed lines.

[0103] The upper conductor portion 31B extends along an imaginary curve L that curves so as to protrude in a direction away from the MR element 15. In Fig. the imaginary curve L is represented by a double-dashed dashed line, which is denoted by the symbol L. The imaginary curve L is a curve parallel to the YZ plane. In the Fig. In the example shown, the direction away from the MR element 15 specifically refers to a direction inclined from the Z direction to the Y direction by a predetermined angle greater than 0° and less than 90°. Viewed from the MR element 15, the imaginary curve L bends to protrude in this direction. A part of the upper conductor portion 31B is parallel to the surfaces of the layers constituting the MR element 15. Fig. a plurality of dashed lines overlapping the MR element 15 and the upper coil part 30U represent the magnetic lines of force corresponding to the partial magnetic field generated by the upper conductor part 31B.

[0104] The lower conductor sections 35B extend along the Y-direction. The lower conductor section 35B does not extend parallel to the surfaces of the layers forming the MR element 15. In Fig. a plurality of dashed lines overlapping the MR element 15 and the lower coil part 30L represent the magnetic lines of force corresponding to the partial magnetic field generated by the lower conductor part 35B.

[0105] Similarly, the upper conductor portion 32B extends along an imaginary curve that curves to protrude in a direction away from the MR element 16. A portion of the upper conductor portion 32B extends parallel to the surfaces of the layers that form the MR element 16. Similarly, the upper conductor portion 33B extends along an imaginary curve to protrude in a direction away from the MR element 17. A portion of the upper conductor portion 33B extends parallel to the surfaces of the layers that form the MR element 17. Similarly, the upper conductor portion 34B extends along an imaginary curve to protrude in a direction away from the MR element 18. A portion of the upper conductor portion 34B extends parallel to the surfaces of the layers that form the MR element 18. All imaginary curves are parallel to the YZ plane.

[0106] Similarly, all lower conductor sections 36B to 38B extend along the Y direction. The lower conductor section 36B is not parallel to the surfaces of the layers forming the MR element 16. The lower conductor section 37B is not parallel to the surfaces of the layers forming the MR element 17. The lower conductor section 38B is not parallel to the surfaces of the layers forming the MR element 18.

[0107] Next, a method for generating the detection value Vs of the present embodiment will be described. When describing one of the MR elements 11 to 14, the MR element will be denoted by reference numeral 10A. When describing one of the MR elements 15 to 18, the MR element will be denoted by reference numeral 10B. The MR element 10A will be referred to as a first MR element 10A, and the MR element 10B will be referred to as a second MR element 10B. The first MR element 10A corresponds to the MR element 10 according to the first embodiment.

[0108] Assuming that the surfaces of the layers constituting the first MR elements 10A are flat surfaces, a direction parallel to the surfaces of the layers and orthogonal to the X direction is referred to as the V direction. The direction opposite to the V direction is referred to as the -V direction. Assuming that the surfaces of the layers are flat surfaces, as described in the first embodiment, the first MR elements 10A on the first side part SD1 are oriented such that the surfaces of the layers are oblique to the XY plane. This makes the V direction different from the Y or -Y direction. In the present embodiment, the V direction is a direction rotated by α from the Y direction to the -Z direction. α is an angle greater than 0° and less than 90°.

[0109] Fig. is an explanatory diagram describing a target magnetic field MF for the first MR element 10A to be detected. In Fig. The position at which the first MR element 10A detects the target magnetic field MF is indicated by the symbol Pa. In the present embodiment, the direction and strength of the target magnetic field MF at the position Pa coincide with those of the target magnetic field MF at the reference position on the rotation axis C (see Fig. ). The direction of the target magnetic field MF at position Pa rotates around position Pa. The target magnetic field MF at position Pa is hereinafter denoted by the symbol MFa.

[0110] In Fig. An imaginary straight line passing through position Pa and parallel to the Y direction is denoted by the symbol LYa. An imaginary straight line passing through position Pa and parallel to the Z direction is denoted by the symbol LZa. An imaginary straight line passing through position Pa and parallel to the V direction is denoted by the symbol LV.

[0111] In the magnetic sensor 101, the directions of magnetization of the magnetizing pin layers 52 in the MR elements 11 to 14 and the shape anisotropy of the free layers 54 in the MR elements 11 to 14 are adjusted so that the strength of the component of the target magnetic field MFa in the direction parallel to the V direction can be detected. Fig. 18, the thick arrows indicate the directions of magnetization in the magnetized layers 52. The X and V directions are in Fig. 18. As shown in Fig. As shown in Figure 18, in the present embodiment, the magnetization directions of the magnetizing pins 52 in the MR elements 11 and 13 are in the V direction. The magnetization directions of the magnetizing pin layers 52 in the MR elements 12 and 14 are in the -V direction. The free layers 54 have shape anisotropy such that the direction of the easy axis of magnetization is parallel to the X direction.

[0112] As in Fig. As shown, the target magnetic field MFa can be regarded as a composite magnetic field composed of a magnetic field MFay in a direction parallel to the Y direction and a magnetic field MFaz in a direction parallel to the Z direction. The MR elements 11 to 14 each detect a composite magnetic field composed of a component of the magnetic field MFay in a direction parallel to the V direction and a component of the magnetic field MFaz in a direction parallel to the V direction. A component in the direction parallel to the V direction is hereinafter referred to as a V component. The composite magnetic field composed of the V component of the magnetic field MFay and the V component of the magnetic field MFaz is referred to as a first composite magnetic field. The differential detector 21 outputs a signal consistent with the strength of the first composite magnetic field as a detection signal S1.

[0113] The strength of the first composite magnetic field is equal to the sum of the strength of the V component of the magnetic field MFay and the strength of the V component of the magnetic field MFaz. Here, the strength of the magnetic field MFay is denoted by the symbol By, and the strength of the magnetic field MFaz is denoted by the symbol Bz. The strength By is expressed in positive values ​​when the direction of the magnetic field MFay is in the Y direction and in negative values ​​when the direction of the magnetic field MFay is in the -Y direction. The strength Bz is expressed in positive values ​​when the direction of the magnetic field MFaz is in the Z direction and in negative values ​​when the direction of the magnetic field MFaz is in the -Z direction. The ratio of a change in the detection signal S1 to a change in the strength of the first composite magnetic field is denoted by the symbol Sa. The detection signal S1 is expressed by the following equation (2): S1=Sa*(By*cos α−Bz*sin α)

[0114] The strength of a V component is expressed in positive values ​​when the direction of the V component is the V direction, and in negative values ​​when the direction of the V component is the -V direction. The positive or negative sign of the strength of the V component of the magnetic field MFay coincides with that of the strength By of the magnetic field MFay. In contrast, the positive or negative sign of the strength of the V component of the magnetic field MFaz is opposite to that of the strength Bz of the magnetic field MFaz. Therefore, in Eq. (2), the strength of the V component of the magnetic field MFay is expressed as "By*cos α" and the strength of the V component of the magnetic field MFaz is expressed as "-Bz*sin α".

[0115] Assuming that the surfaces of the layers constituting the second MR elements 10B are flat surfaces, a direction parallel to the surfaces of the layers and orthogonal to the X direction is referred to as the W direction. The direction opposite to the W direction is referred to as the -W direction. Assuming that the surfaces of the layers are flat surfaces as described above, the second MR elements 10B on the second side part SD2 are arranged in such an orientation that the surfaces of the layers are oblique to the XY plane. This makes the W direction different from the Y or -Y direction. In the present embodiment, the W direction is a direction rotated by α from the Y direction to the Z direction.

[0116] Fig. is an explanatory diagram for describing a target magnetic field MF for the second MR element 10B to be detected. In Fig. The position at which the second MR element 10B detects the target magnetic field MF is indicated by the symbol Pb. In the present illustration, the direction and strength of the target magnetic field MF at the position Pb coincide with those of the target magnetic field MF at the reference position on the rotation axis C. The direction of the target magnetic field MF at the position Pb rotates around the position Pb. The target magnetic field MF at the position Pb is denoted below by the symbol MFb.

[0117] In Fig. An imaginary straight line passing through position Pb and parallel to the Y direction is denoted by the symbol LYb. An imaginary straight line passing through position Pb and parallel to the Z direction is denoted by the symbol LZb. An imaginary straight line passing through position Pb and parallel to the W direction is denoted by the symbol LW.

[0118] In the magnetic sensor 101, the magnetization directions of the magnetized pinning layers 52 in the MR elements 15 to 18 and the shape anisotropy of the free layers 54 in the MR elements 15 to 18 are adjusted so that the strength of the component of the target magnetic field MFb in the direction parallel to the W direction can be detected. The X and W directions are in Fig. For simplicity, Fig. The W-direction and the V-direction are marked by the same arrow. As in Fig. As shown, in the present illustration, the magnetization directions of the magnetized pinning layers 52 in the MR elements 15 and 17 are the W direction. The magnetization directions of the magnetized pinning layers 52 in the MR elements 16 and 18 are the -W direction. The free layer 54 has a shape anisotropy such that the direction of the easy axis of magnetization is parallel to the X direction.

[0119] As in Fig. As shown, the target magnetic field MFb can be regarded as a composite magnetic field composed of a magnetic field MFby in a direction parallel to the Y direction and a magnetic field MFbz in a direction parallel to the Z direction. The MR elements 15 to 18 each detect a composite magnetic field composed of a component of the magnetic field MFby in a direction parallel to the W direction and a component of the magnetic field MFbz in a direction parallel to the W direction. A component in the direction parallel to the W direction is hereinafter referred to as a W component. The composite magnetic field composed of the W component of the magnetic field MFby and the W component of the magnetic field MFbz is referred to as a second composite magnetic field. The differential detector 23 outputs a signal consistent with the strength of the second composite magnetic field as a detection signal S2.

[0120] The strength of the second composite magnetic field is equal to the sum of the strength of the W component of the magnetic field MFby and the strength of the W component of the magnetic field MFbz. Both the strength of the target magnetic field MFb and the strength of the target magnetic field MFa are equal to the strength of the target magnetic field MF at the reference position. The strength of the magnetic field MFby is therefore the same as that of the magnetic field MFay, and the strength of the magnetic field MFbz is the same as that of the magnetic field MFaz. Like the strength of the magnetic field MFay, the strength of the magnetic field MFby is also denoted by the symbol By. Like the strength of the magnetic field MFaz, the strength of the magnetic field MFbz is denoted by the symbol Bz. The ratio of a change in the detection signal S2 to a change in the strength of the second composite magnetic field is denoted by the symbol Sb. The detection signal S2 is expressed by the following equation (3): S2=Sb*(By*cosα+Bz*sinα)

[0121] The strength of the W component is expressed in positive values ​​when the direction of the W component is the W direction, and in negative values ​​when the direction of the W component is the -W direction. The positive or negative sign of the strength of the W component of the magnetic field MFby coincides with that of the strength By of the magnetic field MFby. The positive or negative sign of the strength of the W component of the magnetic field MFbz also coincides with that of the strength Bz of the magnetic field MFbz. Therefore, in Eq. (3), the strength of the W component of the magnetic field MFby is expressed as "By*cos α" and the strength of the W component of the magnetic field MFbz is expressed as "Bz*sin α".

[0122] In the present embodiment, the detection value generation circuit 22 generates the detection value Vs based on the detection signals S1 and S2. The detection value generation circuit 22 can determine the angle that the direction of the target magnetic field MF at the reference position makes with the Z direction as the detection value Vs. This angle is expressed in positive values ​​when the direction of the target magnetic field MF tilts from the Z direction to the Y direction, and in negative values ​​when the direction of the target magnetic field MF tilts from the Z direction to the -Y direction. In such a case, the detection value generation circuit 22 first calculates the values ​​Bys and Bzs based on the detection signals S1 and S2. The value Bys indicates the strength of the component of the target magnetic field MF in the direction parallel to the Y direction at the reference position.The value Bzs indicates the strength of the component of the target magnetic field MF in the direction parallel to the Z direction at the reference position.

[0123] The strength of the Y-direction component of the target magnetic field MF at the reference position is equal to the strength By of the magnetic field MFay or MFby. Assume that the ratio Sa of a change in the detection signal S1 to a change in the strength of the first composite magnetic field and the ratio Sb of a change in the detection signal S2 to a change in the strength of the second composite magnetic field are equal. By replacing both Sa in Equation (2) and Sb in Equation (3) with Sc, Equations (2) and (3) yield the strength By, expressed by the following Equation (4): Through=(S2+S1) / (2Sc*cosα)

[0124] For example, the detection value generation circuit 22 calculates the value Bys using the right-hand side of Equation (4). Sc is determined in advance.

[0125] The strength of the Z-direction component of the target magnetic field MF at the reference position is equal to the strength Bz of the magnetic field MFaz or MFbz. As in Eq. (4), replacing Sa in Eq. (2) and Sb in Eq. (3) with Sc yields the strength Bz expressed by the following Eq. (5): Bz=(S2−S1) / (2Sc*sinα)

[0126] For example, the circuit for generating the detection value 22 calculates the value Bzs using the right side of Eq.

[0127] The detection value generation circuit 22 then determines the angle formed by the direction of the target magnetic field MF with respect to the Z direction as the detection value Vs using the values ​​Bys and Bzs. Specifically, for example, the detection value generation circuit 22 generates the detection value Vs by the following equation: Vs=90°−atan(Bzs / Bys)=90°−θs “atan” stands for arctangent.

[0128] For θs in the range from 0° to less than 360°, Equation (6) gives two solutions of θs that differ by 180°. Which of the two solutions of θs in Equation (6) is the true value of θs can be determined by combining the signs of Bys and Bzs. The detection value generation circuit 22 determines θs in the range from 0° to less than 360° according to Equation (6) and determines it by combining the signs of Bys and Byz.

[0129] The configuration, operation, and effects of the present embodiment are otherwise the same as those of the first embodiment.

[0130] The present invention is not limited to the above embodiments, and various modification examples can be cited. The shape and arrangement of the at least one conductor part of the coil 30 are not limited to the examples described in the above embodiments and can be freely determined as long as the requirements set forth in the claims are met. For example, a conductor portion located on the bottom surface 40b of the support member 40 may extend along an imaginary curve curved to protrude in a direction away from the corresponding MR element.

[0131] The upper surface 40a of the support member 40 may include a plurality of curved surface portions. The plurality of curved surface portions each have the same shape as that of the curved surface portion 40a1. The plurality of curved surface portions may be arranged to be aligned in the Y direction. In such a case, the MR elements may be located on the respective plurality of curved surface portions.

[0132] The detection value generation circuit 22 of the magnetic sensor 1 according to the first embodiment may generate a value representing the strength of a component of the target magnetic field MF in a direction parallel to the Z direction as a detection value Vs. The detection value generation circuit 22 of the magnetic sensor 1 according to the first embodiment may generate a set of values ​​Bys and Bzs as a detection value Vs.

Claims

[1] Magnetic sensor (1; 101), comprising: at least one magnetoresistive element (11, 12, 13, 14) whose resistance changes with an external magnetic field; and a coil (30) generating a coil magnetic field, wherein the coil magnetic field is a magnetic field to be applied to the at least one magnetoresistive element (11, 12, 13, 14), wherein the coil (30) has at least one conductor section (31, 32, 33, 34; 31A, 31B, 32A, 32B, 33A, 33B, 34A, 34B), the coil magnetic field contains a partial magnetic field generated by each of the at least one conductor section (31, 32, 33, 34; 31A, 31B, 32A, 32B, 33A, 33B, 34A, 34B), the partial magnetic field generated by each of the at least one conductor section (31, 32, 33, 34; 31A, 31B, 32A, 32B, 33A, 33B, 34A, 34B) is applied to a corresponding one of the at least one magnetoresistive element (11, 12, 13, 14), the corresponding one of the at least one magnetoresistive element (11, 12, 13, 14) being arranged at a position closest to the conductor section, each of the at least one conductor section (31, 32, 33, 34; 31A, 31B, 32A, 32B, 33A, 33B, 34A, 34B) extends in a curve to protrude in a direction away from the corresponding magnetoresistive element, the magnetic sensor (1; 101) further comprises a support element (40) which carries the at least one magnetoresistive element (11, 12, 13, 14), the support element (40) has an upper surface (40a) opposite the at least one magnetoresistive element (11, 12, 13, 14) and a lower surface (40b) located on a side opposite the upper surface (40a), the upper surface (40a) of the support member (40) has a curved surface portion (40a1) which is curved so as to protrude in a direction away from the lower surface (40b) of the support member (40); and the at least one magnetoresistive element is located on the curved surface portion (40a1). [2] Magnetic sensor (1; 101) according to claim 1, wherein: the at least one magnetoresistive element (11, 12, 13, 14) each has a bottom surface opposite the support element (40); and the bottom surface of each of the at least one magnetoresistive element (11, 12, 13, 14) is a curved surface that curves along the curved surface portion (40a1). [3] Magnetic sensor (1) according to claim 1 or 2, wherein: the curved surface portion (40a1) of the upper surface (40a) of the support member (40) comprises a central portion (C1) extending along a first direction and disposed at a center of the curved surface portion (40a1) in a second direction orthogonal to the first direction, and a first side portion (SD1) and a second side portion (SD2) disposed on both sides of the central portion (C1) in the second direction; the first side portion (SD1) and the second side portion (SD2) are two curved slopes located at positions closer to the bottom surface (40b) of the support member (40) than the central portion (C1), and a distance therebetween increases toward the bottom surface (40b) of the support member (40); and the at least one magnetoresistive element (11, 12, 13, 14) is located on the first side part (SD1). [4] Magnetic sensor (101) according to claim 1 or 2, wherein: the curved surface portion (40a1) of the upper surface (40a) of the support member (40) comprises a central portion (C1) extending along a first direction and disposed at a center of the curved surface portion (40a1) in a second direction orthogonal to the first direction, and a first side portion (SD1) and a second side portion (SD2) disposed on both sides of the central portion (C1) in the second direction; the first side portion (SD1) and the second side portion (SD2) are two curved slopes located at positions closer to the bottom surface (40b) of the support member (40) than the central portion (C1), and a distance therebetween increases toward the bottom surface (40b) of the support member (40); and the at least one magnetoresistive element (11, 12, 13, 14) comprises at least a first magnetoresistive element (11, 12, 13, 14) located on the first side portion (SD1) and at least one second magnetoresistive element (15, 16, 17, 18) located on the second side portion (SD2). [5] Magnetic sensor (1; 101) according to one of claims 1 to 4, wherein the at least one conductor portion (31, 32, 33, 34; 31A, 31B, 32A, 32B, 33A, 33B, 34A, 34B) is in a position such that the conductor portion is sandwiched with the at least one magnetoresistive element (11, 12, 13, 14) and the support element (40). [6] Magnetic sensor (1; 101) according to claim 5, further comprising an insulating layer (65, 66, 67) covering the at least one magnetoresistive element (11, 12, 13, 14) and the upper surface (40a) of the support member (40), wherein the at least one conductor section (31, 32, 33, 34; 31A, 31B, 32A, 32B, 33A, 33B, 34A, 34B) is located on the insulating layer (65, 66, 67). [7] Magnetic sensor (1; 101) according to claim 5 or 6, wherein: the at least one magnetoresistive element (11, 12, 13, 14) each contains a stack of a plurality of layers; and the at least one conductor section (31, 32, 33, 34; 31A, 31B, 32A, 32B, 33A, 33B, 34A, 34B) each extends partially parallel to surfaces of the layers forming one of the at least one magnetoresistive elements (11, 12, 13, 14) corresponding to the conductor section. [8] Magnetic sensor (1; 101) according to claim 5 or 6, wherein: the at least one magnetoresistive element (11, 12, 13, 14) each contains a stack of a plurality of layers; and the at least one conductor section (31, 32, 33, 34; 31A, 31B, 32A, 32B, 33A, 33B, 34A, 34B) each extends partially non-parallel to surfaces of the layers forming one of the at least one magnetoresistive elements (11, 12, 13, 14) corresponding to the conductor section. [9] Magnetic sensor (1; 101), comprising: at least one magnetoresistive element (11, 12, 13, 14) whose resistance changes with an external magnetic field; and a coil (30) generating a coil magnetic field, wherein the coil magnetic field is a magnetic field to be applied to the at least one magnetoresistive element (11, 12, 13, 14), wherein the coil (30) has at least one conductor section (31, 32, 33, 34; 31A, 31B, 32A, 32B, 33A, 33B, 34A, 34B), the coil magnetic field contains a partial magnetic field generated by each of the at least one conductor section (31, 32, 33, 34; 31A, 31B, 32A, 32B, 33A, 33B, 34A, 34B), the partial magnetic field generated by each of the at least one conductor section (31, 32, 33, 34; 31A, 31B, 32A, 32B, 33A, 33B, 34A, 34B) is applied to a corresponding one of the at least one magnetoresistive element (11, 12, 13, 14), the corresponding one of the at least one magnetoresistive element (11, 12, 13, 14) being arranged at a position closest to the conductor section, each of the at least one conductor section (31, 32, 33, 34; 31A, 31B, 32A, 32B, 33A, 33B, 34A, 34B) extends in a curve to protrude in a direction away from the corresponding magnetoresistive element, the magnetic sensor (1; 101) further comprises a support element (40) which carries the at least one magnetoresistive element (11, 12, 13, 14), the at least one conductor section (31, 32, 33, 34; 31A, 31B, 32A, 32B, 33A, 33B, 34A, 34B) is in a position such that the conductor section is sandwiched between the at least one magnetoresistive element (11, 12, 13, 14) and the support element (40), the coil (30) further comprises at least one second conductor section (35, 36, 37, 38; 35A, 35B, 36A, 36B, 37A, 37B, 38A, 38B); the at least one second conductor section (35, 36, 37, 38; 35A, 35B, 36A, 36B, 37A, 37B, 38A, 38B) is a different part of the coil (30) than the at least one conductor section (31, 32, 33, 34; 31A, 31B, 32A, 32B, 33A, 33B, 34A, 34B); the coil magnetic field further includes a second partial magnetic field generated by each of the at least one second conductor portion (35, 36, 37, 38; 35A, 35B, 36A, 36B, 37A, 37B, 38A, 38B); the at least one second conductor section (35, 36, 37, 38; 35A, 35B, 36A, 36A, 36B, 37A, 37B, 38A, 38B) is located on the side of the bottom surface (40b) of the support element (40); and the second partial magnetic field generated by each of the at least one second conductor section (35, 36, 37, 38; 35A, 35B, 36A, 36B, 37A, 37B, 38A, 38B) is applied to one of the at least one magnetoresistive element (11, 12, 13, 14) that is closest to the second conductor section. [10] Magnetic sensor (1; 101) according to claim 9, wherein: the at least one magnetoresistive element (11, 12, 13, 14) each contains a stack of a plurality of layers; the at least one conductor section (31, 32, 33, 34; 31A, 31B, 32A, 32B, 33A, 33B, 34A, 34B) each extends partially parallel to surfaces of the layers forming one of the at least one magnetoresistive element (11, 12, 13, 14) corresponding to the conductor section; and the at least one second conductor section (35, 36, 37, 38; 35A, 35B, 36A, 36B, 37A, 37B, 38A, 38B) each extends non-parallel to surfaces of the layers forming one of the at least one magnetoresistive element (11, 12, 13, 14) corresponding to the second conductor section. [11] Magnetic sensor (1; 101) according to claim 9, wherein: the at least one magnetoresistive element (11, 12, 13, 14) each contains a stack of a plurality of layers; the at least one conductor section (31, 32, 33, 34; 31A, 31B, 32A, 32B, 33A, 33B, 34A, 34B) each extends non-parallel to surfaces of the layers forming one of the at least one magnetoresistive element (11, 12, 13, 14), namely the one corresponding to the conductor section; and the at least one second conductor section (35, 36, 37, 38; 35A, 35B, 36A, 36B, 37A, 37B, 38A, 38B) each extends partially parallel to surfaces of the layers forming one of the at least one magnetoresistive element (11, 12, 13, 14), namely the one corresponding to the second conductor section. [12] The magnetic sensor (1; 101) according to any one of claims 1 to 11, wherein: the at least one magnetoresistive element (11, 12, 13, 14) each has a magnetization-fixed layer (52) with a first magnetization whose direction is fixed, and a free layer (54) with a second magnetization whose direction can be changed with the external magnetic field; and the magnetic field of the coil is intended to orient the direction of the second magnetization of the free layer (54) in a predetermined direction.

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