Magnetic sensor, magnetic field detection device, position detection device, lens module, and imaging apparatus

Abstract

To provide a magnetic sensor applied to a magnetic field detection device that can accurately detect a magnetic field in a predetermined direction while being compact.SOLUTION: A magnetic sensor comprises a stacked structure in which a first layer including a magnetic yoke, and a second layer including a magnetic field detection element and a plurality of magnetic field generators each applying a magnetic field to the magnetic field detection element and arranged discretely along a first axis direction, are stacked in order in a second axis direction. The magnetic field detection element is interposed between two magnetic field generators selected from the plurality of magnetic field generators in the first axis direction. The magnetic yoke extends in the first axis direction, and is adjacent to the magnetic field detection element in a third axis direction in a plan view as viewed in the second axis direction. The plurality of magnetic field generators arranged in the first axis direction include a first magnetic field generator arranged at a first end in the first axis direction and a second magnetic field generator arranged at a second end in the first axis direction. A distance between a first edge of the first magnetic field generator and a second edge of the second magnetic field generator is smaller than a length of the magnetic yoke in the second axis direction.SELECTED DRAWING: Figure 1B

Description

[Technical Field]

[0001] The present disclosure relates to a magnetic sensor, and a magnetic field detection device, a position detection device, a lens module, and an imaging device that include the magnetic sensor. [Background technology]

[0002] In recent years, magnetic sensors using magnetoresistive elements have been used in various applications. Examples of magnetoresistive elements include spin-valve magnetoresistive elements. In magnetic sensors, a bias magnetic field may be applied to the magnetoresistive element for various purposes. For example, Patent Document 1 discloses a magnetic sensor equipped with multiple bias magnetic field application units that apply bias magnetic fields in opposite directions to a first portion and a second portion of a single free magnetic layer in order to reduce an offset in the resistance of the free magnetic layer of a giant magnetoresistive element. Each of the multiple bias magnetic field application units has a structure in which a magnetic layer is sandwiched between two antiferromagnetic layers. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Japanese Patent Application Publication No. 2022-77691 Summary of the Invention [Problem to be solved by the invention]

[0004] In a magnetic field detection device including a magnetic sensor, it is sometimes necessary to detect a magnetic field including a component perpendicular to the surface of the substrate using a magnetoresistive element provided on the substrate. Furthermore, there is a demand for such a magnetic field detection device to be both smaller and have improved detection accuracy.

[0005] Therefore, it is desirable to provide a magnetic field detection device that is small and yet capable of detecting a magnetic field in a predetermined direction with high accuracy, and a magnetic sensor that can be applied to such a magnetic field detection device. [Means for solving the problem]

[0006] A magnetic sensor according to a first embodiment of the present disclosure has a laminated structure. The laminated structure includes a first layer including a magnetic yoke and a second layer including a magnetic field detection element and a plurality of magnetic field generators that apply a magnetic field to the magnetic field detection element and are discretely arranged along the first axis direction, stacked in this order in a second axis direction intersecting the first axis direction. The magnetic field detection element is sandwiched between two magnetic field generators selected from the plurality of magnetic field generators in the first axis direction. The magnetic yoke extends in the first axis direction and is adjacent to the magnetic field detection element in a third axis direction intersecting both the first axis direction and the second axis direction in a plan view viewed in the second axis direction. The plurality of magnetic field generators arranged in the first axis direction include a first magnetic field generator arranged at a first end in the first axis direction and a second magnetic field generator arranged at a second end opposite the first end in the first axis direction. The distance between the first edge of the first magnetic field generator that is located farthest from the second magnetic field generator and the second edge of the second magnetic field generator that is located farthest from the first magnetic field generator is shorter than the length of the magnetic yoke in the second axial direction. A magnetic field detection device, a position detection device, a lens module, and an imaging device according to a first embodiment of the present disclosure include the magnetic sensor according to the first embodiment of the present disclosure.

[0007] A magnetic sensor according to a second embodiment of the present disclosure includes a magnetic field detection element and a plurality of magnetic field generators that apply a magnetic field to the magnetic field detection element and are discretely arranged along a first axis direction. The plurality of magnetic field generators are exchange-coupled bias structures that include a ferromagnetic body and an antiferromagnetic body that contacts the ferromagnetic body and is exchange-coupled with the ferromagnetic body. The magnetic field detection element is sandwiched between two magnetic field generators selected from the plurality of magnetic field generators in the first axis direction. The magnetic yoke extends in the first axis direction and is adjacent to the magnetic field detection element in a third axis direction that intersects both the first axis direction and the second axis direction in a plan view viewed in the second axis direction. The plurality of magnetic field generators arranged in the first axis direction include a first magnetic field generator arranged at a first end in the first axis direction and a second magnetic field generator arranged at a second end opposite the first end in the first axis direction. The distance between the first edge of the first magnetic field generator that is located farthest from the second magnetic field generator and the second edge of the second magnetic field generator that is located farthest from the first magnetic field generator is shorter than the length of the magnetic yoke in the second axial direction. A magnetic field detection device, a position detection device, a lens module, and an imaging device according to a second embodiment of the present disclosure include the magnetic sensor according to the first embodiment of the present disclosure. [Effects of the Invention]

[0008] According to the magnetic sensor and magnetic field detection device as the first embodiment of the present disclosure, and the magnetic sensor and magnetic field detection device as the second embodiment of the present disclosure, a magnetic field in a predetermined direction can be detected with high accuracy despite being small in size. [Brief explanation of the drawings]

[0009] [Figure 1A] FIG. 1A is a plan view illustrating an example of a planar configuration of a magnetic sensor according to a first embodiment of the present disclosure. [Figure 1B] FIG. 1B is a first cross-sectional view illustrating an example of the cross-sectional configuration of the magnetic sensor shown in FIG. 1A. [Figure 1C] FIG. 1C is a second cross-sectional view illustrating an example of the cross-sectional configuration of the magnetic sensor illustrated in FIG. 1A. [Figure 1D]FIG. 1D is a third cross-sectional view illustrating an example of the cross-sectional configuration of the magnetic sensor illustrated in FIG. 1A. [Figure 2A] FIG. 2A is a plan view schematically illustrating a step of a method for manufacturing the magnetic sensor shown in FIG. 1A. [Figure 2B] FIG. 2B is a plan view schematically showing a step subsequent to FIG. 2A. [Figure 2C] FIG. 2C is a plan view schematically illustrating a step subsequent to FIG. 2B. [Figure 2D] FIG. 2D is a plan view schematically illustrating a step subsequent to FIG. 2C. [Figure 3] FIG. 3 is a plan view showing an example of the planar configuration of a magnetic sensor as a reference example. [Figure 4] FIG. 4 is a schematic plan view illustrating an example of the overall configuration of a magnetic field detection device according to the second embodiment of the present disclosure. [Figure 5] FIG. 5 is a circuit diagram showing an example of the circuit configuration of a magnetic field detection circuit included in the magnetic field detection device shown in FIG. [Figure 6] FIG. 6 is a characteristic diagram showing the output characteristics of the magnetic field detection device shown in FIG. [Figure 7] FIG. 7 is a perspective view illustrating an example of the overall configuration of a magnetic compass according to the third embodiment of the present disclosure. [Figure 8A] FIG. 8A is a plan view illustrating an example of the planar configuration of a magnetic sensor mounted on the magnetic compass shown in FIG. [Figure 8B] FIG. 8B is a first cross-sectional view illustrating an example of the cross-sectional configuration of the magnetic sensor shown in FIG. 8A. [Figure 8C] FIG. 8C is a second cross-sectional view illustrating an example of the cross-sectional configuration of the magnetic sensor illustrated in FIG. 8A. [Figure 9] FIG. 9 is a schematic perspective view illustrating an example of the overall configuration of an imaging device according to the fourth embodiment of the present disclosure. DETAILED DESCRIPTION OF THE INVENTION

[0010] DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, preferred embodiments of the present invention will be described in detail with reference to the accompanying drawings. The description will be made in the following order: 1. First embodiment 1 is an example of a magnetic sensor including a pair of yokes, a plurality of magnetoresistive elements, and a plurality of magnetic field generators. 2. Second embodiment 1 is an example of a magnetic field detection device equipped with multiple magnetic sensors. 3. Third Embodiment Example of a magnetic compass with multiple magnetic sensors 4. Fourth embodiment and its modifications Example of an imaging device including a lens module having multiple magnetic sensors 5. Other Modifications

[0011] <1. First embodiment> [Configuration of magnetic sensor 1] First, the configuration of a magnetic sensor 1 according to a first embodiment of the present disclosure will be described with reference to FIGS. 1A to 1C.

[0012] FIG. 1A is a plan view illustrating an example of the planar configuration of the magnetic sensor 1. FIG. 1B is a cross-sectional view illustrating an example of the cross-sectional configuration of the magnetic sensor 1, taken along the IB-IB cutting line shown in FIG. 1A. FIG. 1C is a cross-sectional view illustrating an example of the cross-sectional configuration of the magnetic sensor 1, taken along the IC-IC cutting line shown in FIG. 1A. FIG. 1D is a cross-sectional view illustrating an example of the cross-sectional configuration of the magnetic sensor 1, taken along the ID-ID cutting line shown in FIG. 1A. The X-axis direction, Y-axis direction, and Z-axis direction shown in FIGS. 1A to 1D are specific examples corresponding to the "third axis direction," "first axis direction," and "second axis direction," respectively, according to an embodiment of the present disclosure. The X-axis direction, Y-axis direction, and Z-axis direction are orthogonal to one another. Note that, in this specification, "orthogonal" is not limited to a state in which the directions intersect at a strict geometric angle of 90°, but also includes a state in which the directions intersect within a range of, for example, approximately 90±10°. Furthermore, in this specification, with respect to an arbitrary component or part as a reference, a position on the +Z side or the +Z direction as viewed from that component or part may be described as "upward," and a position on the -Z side or the -Z direction as viewed from that component or part may be described as "downward." Also, in this specification, for example, in the plan view shown in FIG. 1A, the direction from one or more magnetic field detection elements 30 (described later) along the X-axis direction toward an upper magnetic yoke 50 (described later) is defined as the +X direction, and the direction from one or more magnetic field detection elements 30 along the X-axis direction toward a lower magnetic yoke 20 (described later) is defined as the -X direction.

[0013] As shown in FIGS. 1B to 1D, the magnetic sensor 1 includes, for example, a substrate 10 and a laminated structure S1 in which a first layer L1, a second layer L2, and a third layer L3 are laminated in this order in the +Z direction on the substrate 10. In other words, in this specification, the direction from the first layer L1 to the third layer L3 is defined as the +Z direction, and the direction from the third layer L3 to the first layer L1 is defined as the -Z direction. The substrate 10 includes a front surface 10FS and a back surface 10BS. The first to third layers L1 to L3 are provided above the front surface 10FS of the substrate 10. In the configuration example shown in FIGS. 1A to 1D, the front surface 10FS and the back surface 10BS are planes perpendicular to the Z-axis direction. That is, the front surface 10FS and the back surface 10BS are XY planes extending in the X-axis direction and the Y-axis direction, respectively. The substrate 10 is a support that supports multiple components constituting each of the first to third layers L1 to L3, which will be described below. The substrate 10 may be a semiconductor substrate made of, for example, silicon (Si), or may be a magnetic shield made of a soft magnetic material such as permalloy (NiFe). The substrate 10 is a specific example corresponding to a "support" according to one embodiment of the present disclosure.

[0014] (First layer) The first layer L1 includes a lower magnetic yoke 20, an insulating layer Z1, and a plurality of lower electrodes 61. The lower magnetic yoke 20 is provided in a partial region of the surface 10FS of the substrate 10. The lower magnetic yoke 20 is made of a soft ferromagnetic material such as permalloy (NiFe) and guides the magnetic field lines ML of the Z-axis component of the magnetic field to be detected toward the magnetic field detection element 30 (described later). The lower magnetic yoke 20 extends in the Y-axis direction and is disposed adjacent to the magnetic field detection element 30 in the X-axis direction in a plan view viewed in the Z-axis direction. The lower magnetic yoke 20 is a specific example corresponding to a "magnetic yoke" as one aspect of the present disclosure. The insulating layer Z1 is provided in a region of the surface 10FS surrounding the lower magnetic yoke 20. The insulating layer Z1 is made of a non-magnetic insulating material such as AlOx (aluminum oxide), AlN (aluminum nitride), or SiOx (silicon oxide). The lower electrode 61 embedded in the insulating layer Z1 is provided so that a portion thereof is exposed on the upper surface of the first floor L1, i.e., the upper surface of the insulating layer Z1 opposite the surface 10FS. The lower electrode 61 is spaced apart from the lower magnetic yoke 20. The lower electrode 61 contacts the lower surface of the magnetic field detection element 30 (described later) and is electrically connected to the magnetic field detection element 30. The lower electrode 61 can be made of a highly conductive non-magnetic material such as Cu (copper). Note that the lower electrode 61 is omitted from FIG. 1A to improve the visibility of the magnetic field detection element 30 and the magnetic field generator 40 (described later).

[0015] (Second tier) The second floor L2 includes one or more magnetic field detection elements 30, multiple magnetic field generators 40, and an insulating layer Z2. In the configuration example shown in FIG. 1B, the magnetic sensor 1 has four magnetic field detection elements 30 (30-1 to 30-4) and five magnetic field generators 40 (40-1 to 40-5). However, in the present disclosure, the number of magnetic field detection elements 30 and the number of magnetic field generators 40 can be selected arbitrarily. The multiple magnetic field generators 40 are discretely arranged along the Y-axis direction relative to the one or more magnetic field detection elements 30. The multiple magnetic field generators 40 each apply a bias magnetic field parallel to the Y-axis direction to the one or more magnetic field detection elements 30. In this embodiment, the direction from magnetic field generator 40-5 to magnetic field generator 40-1 is defined as the +Y direction, and the direction from magnetic field generator 40-1 to magnetic field generator 40-5 is defined as the -Y direction. In this embodiment, each of the multiple magnetic field generators 40 applies a bias magnetic field in the +Y direction to one or more magnetic field detection elements 30. A magnetic field detection element 30 is sandwiched between two magnetic field generators 40 selected from the multiple magnetic field generators in the Y-axis direction. Therefore, the magnetic field generators 40 and the magnetic field detection elements 30 are alternately arranged along the Y-axis direction. The magnetic field generators 40 and the magnetic field detection elements 30 are spaced apart, and as shown in FIG. 1D, an insulating layer Z2 may be filled in the gap between the magnetic field generators 40 and the magnetic field detection elements 30. The magnetic field detection elements 30 are provided on a lower electrode 61. The magnetic field detection elements 30 are electrically connected to the lower electrode 61. As shown in FIG. 1A, the magnetization directions M40 (M40-1 to M40-5) of the multiple magnetic field generators 40 (40-1 to 40-5) are inclined at an angle of less than 45° with respect to the Y-axis direction. It is particularly desirable that the magnetization directions M40 (M40-1 to M40-5) substantially coincide with the Y-axis direction. Furthermore, both the magnetic field detection element 30 and the magnetic field generator 40 are provided at positions that do not overlap with the lower magnetic yoke 20 in a plan view seen in the Z-axis direction. The magnetic field detection element 30 is a specific example corresponding to a "magnetic field detection element" according to one aspect of the present disclosure. The magnetic field generator 40 is a specific example corresponding to a "magnetic field generator" according to one aspect of the present disclosure.

[0016] As shown in FIG. 1B , of the multiple magnetic field generators 40 aligned in the Y-axis direction, magnetic field generator 40-1 is located at the end closest to the +Y side in the Y-axis direction, and magnetic field generator 40-5 is located at the end closest to the -Y side in the Y-axis direction. In the magnetic sensor 1, the distance D12 between the first edge T1 of magnetic field generator 40-1 and the second edge T2 of magnetic field generator 40-7 is shorter than the length L20 of the lower magnetic yoke 20 in the Y-axis direction. That is, the length L20 of the lower magnetic yoke 20 is longer than the distance D12. Specifically, the length L20 of the lower magnetic yoke 20 is the length from the edge 20T1 on the +Y side of the lower magnetic yoke 20 to the edge 20T2 on the -Y side of the lower magnetic yoke 20. The first edge T1 is the edge of magnetic field generator 40-1 located farthest from magnetic field generator 40-5. The second edge T2 is the edge of the magnetic field generator 40-5 that is located farthest from the magnetic field generator 40-1.

[0017] The magnetic field detection element 30 is, for example, a magnetoresistive element (MR element). The MR element may be a spin-valve MR element or an AMR (anisotropic magnetoresistive) element. When the magnetic field detection element 30 is a spin-valve MR element, as shown in FIG. 1D, the magnetic field detection element 30 has a structure in which an antiferromagnetic layer 31, a magnetization fixed layer 32 having magnetization M32 fixed in a predetermined direction, a gap layer 33, and a magnetization free layer 34 having magnetization M34 whose direction changes depending on the direction of the applied magnetic field are stacked in this order. In this embodiment, a case in which the magnetic field detection element 30 is a spin-valve MR element will be described as an example. The magnetic field detection element 30 may be a TMR (tunneling magnetoresistive) element or a GMR (giant magnetoresistive) element. When the magnetic field detection element 30 is a TMR element, the gap layer is a tunnel barrier layer. When the magnetic field detection element 30 is a GMR element, the gap layer is a non-magnetic conductive layer. In the magnetic field detection element 30, the resistance value changes depending on the angle that the magnetization direction of the magnetization free layer makes with respect to the direction of the magnetization M32 of the magnetization fixed layer 32. In the magnetic field detection element 30 of this embodiment, the direction of the magnetization M34 of the magnetization free layer 34 is configured to be rotatable within the XY plane. The resistance value of the magnetic field detection element 30, which is an MR element, is minimum when the angle between the direction of the magnetization M34 of the magnetization free layer 34 and the direction of the magnetization M32 of the magnetization fixed layer 32 is 0°, and is maximum when the angle is 180°. In the XY plane, the longitudinal direction of the magnetic field detection element 30 is preferably the Y-axis direction. That is, in the magnetic field detection element 30, the magnetization free layer 34 has shape anisotropy in the Y-axis direction, and the easy axis of magnetization of the magnetization free layer 34 is the Y-axis direction. The direction of the magnetization M32 of the magnetization fixed layer 32 in the magnetic field detection element 30 is preferably along the X-axis direction (+X direction in the configuration example of FIG. 1D) which is perpendicular to the Y-axis direction.

[0018] The length L30 of the magnetic field detection element 30 in the Y-axis direction is preferably shorter than the length L40 of the magnetic field generator 40 in the Y-axis direction. This is because the linearity of the change in electrical resistance value relative to the change in the strength of the magnetic field to be detected is improved in the magnetic field detection element 30. Furthermore, the width W30 of the magnetic field detection element 30 in the X-axis direction is narrower than, for example, the width W40 of each of the magnetic field generators 40 in the X-axis direction.

[0019] 1D, the magnetic field generator 40 has a laminated structure of, for example, an antiferromagnetic layer 41 and a ferromagnetic layer 42. The antiferromagnetic layer 41 and the ferromagnetic layer 42 are in contact with each other and are exchange-coupled. Therefore, the magnetic field generator 40 is an exchange-coupled bias structure. The antiferromagnetic layer 41 is a specific example corresponding to an "antiferromagnetic material" according to one aspect of the present disclosure. The ferromagnetic layer 42 is a specific example corresponding to a "ferromagnetic material" according to one aspect of the present disclosure.

[0020] The ferromagnetic layer 42 has magnetization as a whole. The magnetization of the ferromagnetic layer 42 as a whole is the volume average of the vector sum of the magnetic moments of each unit, such as an atom or crystal lattice, in the entire ferromagnetic layer 42. Hereinafter, the magnetization of the ferromagnetic layer 42 as a whole will be simply referred to as the magnetization of the ferromagnetic layer 42.

[0021] The ferromagnetic layer 42 may be formed of a single layer film or a multilayer film. The ferromagnetic layer 42 is formed of a ferromagnetic material containing one or more elements selected from the group consisting of Co (cobalt), Fe (iron), and Ni (nickel). Specific examples include CoFe, CoFeB, and CoNiFe.

[0022] The antiferromagnetic layer 42 is made of an antiferromagnetic material such as IrMn or PtMn.

[0023] In the magnetic field generator 40, the direction of magnetization of the ferromagnetic layer 42 is determined by exchange coupling between the antiferromagnetic layer 41 and the ferromagnetic layer 42. This provides the magnetic field generator 40 with high resistance to disturbance magnetic fields. The direction of magnetization of the ferromagnetic layer 42 coincides with the magnetization direction M40.

[0024] When viewed in the Y-axis direction, at least a portion of the magnetization free layer 34 of the magnetic field detection element 30 may overlap with at least a portion of the ferromagnetic layer 42 of the magnetic field generator 40. In the configuration example shown in FIG. 1D , when viewed in the Y-axis direction, the entire magnetization free layer 34 overlaps with a portion of the ferromagnetic layer 42.

[0025] (Third tier) The third layer L3 includes an upper magnetic yoke 50, an insulating layer Z3, and a plurality of upper electrodes 62. As shown in FIGS. 1A to 1C, the upper magnetic yoke 50 extends in the Y-axis direction and is disposed at a position not overlapping the lower magnetic yoke 20, the magnetic field detection element 30, and the magnetic field generator 40 in a plan view in the Z-axis direction. That is, the upper magnetic yoke 50 is disposed in a region opposite the region in which the lower magnetic yoke 20 is disposed, as viewed from the magnetic field detection element 30 and the magnetic field generator 40, in the X-axis direction. The upper magnetic yoke 50 is made of a soft ferromagnetic material such as permalloy (NiFe) and guides the magnetic field lines ML toward the magnetic field detection element 30 (described later). The insulating layer Z3 is disposed in a region surrounding the upper magnetic yoke 50. The insulating layer Z3 is made of a non-magnetic insulating material such as AlOx (aluminum oxide), AlN (aluminum nitride), or SiOx (silicon oxide). The upper electrode 62, embedded in the insulating layer Z3, is provided so that the lower surface of the third floor L3, i.e., a portion of the surface of the insulating layer Z3 facing the magnetic field detection element 30, is exposed. The upper electrode 62 is spaced apart from the upper magnetic yoke 50. The upper electrode 62 contacts the upper surface of the magnetic field detection element 30 and is electrically connected to the magnetic field detection element 30. The upper electrode 62 can be made of a highly conductive non-magnetic material such as Cu (copper). Note that the upper electrode 62 is not shown in FIG. 1A to improve the visibility of the magnetic field detection element 30 and the magnetic field generator 40.

[0026] In the magnetic sensor 1, the multiple magnetic field detection elements 30 arranged in the Y-axis direction are electrically connected in series via multiple lower electrodes 61 and multiple upper electrodes 62. That is, one lower electrode 61 contacts the lower surface of each of two adjacent magnetic field detection elements 30 in the Y-axis direction, electrically connecting the two magnetic field detection elements 30. Also, one upper electrode 62 contacts the upper surface of each of two adjacent magnetic field detection elements 30 in the Y-axis direction, electrically connecting the two magnetic field detection elements 30. However, the combination of a pair of magnetic field detection elements 30 connected by the lower electrode 61 is always different from the combination of a pair of magnetic field detection elements 30 connected by the upper electrode 62. Specifically, for example, as shown in FIG. 1C , the magnetic field detection element 30-3 is electrically connected to the magnetic field detection element 30-2, which is located on the +Y side of the magnetic field detection element 30-3, via the upper electrode 62, and is electrically connected to the magnetic field detection element 30-4, which is located on the -Y side of the magnetic field detection element 30-3, via the lower electrode 61. The magnetic field generator 40 may be in contact with either the lower electrode 61 or the upper electrode 62, but is arranged so as not to be in contact with both the lower electrode 61 and the upper electrode 62. The magnetic field generator 40 may be insulated from both the lower electrode 61 and the upper electrode 62.

[0027] [Method of manufacturing magnetic sensor 1] Next, a method for manufacturing the magnetic sensor 1 will be described with reference to FIGS. 2A to 2G in addition to FIGS. 1A to 1D.

[0028] First, as shown in FIG. 2A, a lower magnetic yoke 20, an insulating layer Z1, and a plurality of lower electrodes 61 are formed on a substrate 10. In this process, the lower magnetic yoke 20 is formed to extend in the Y-axis direction. The plurality of lower electrodes 61 are arranged at predetermined intervals in the Y-axis direction. FIG. 2A illustrates the case where two lower electrodes 61-1 to 61-2 are formed.

[0029] Next, as shown in FIG. 2B, multiple magnetic field detection elements 30 are formed adjacent to the lower magnetic yoke 20 in the X-axis direction. Here, one or two magnetic field detection elements 30 are formed on one lower electrode 61. Specifically, magnetic field detection elements 30-1 and 30-2 are formed on the lower electrode 61-1, and magnetic field detection elements 30-3 and 30-4 are formed on the lower electrode 61-2. In the process of forming the magnetic field detection elements 30-1 to 30-4, first, an antiferromagnetic layer 31, a magnetization fixed layer 32, a gap layer 33, and a magnetization free layer 34 are sequentially stacked on the lower electrode 61 by, for example, sputtering to form a laminated film, and then processed into a predetermined planar shape. Next, the laminated film processed into the predetermined planar shape is irradiated with laser while applying an external magnetic field in, for example, the +X direction, thereby fixing the direction of the magnetization M32 of the magnetization fixed layer 32 in the +X direction.

[0030] 2C, a plurality of magnetic field generators 40 are formed so as to sandwich each of the plurality of magnetic field detection elements 30 in the Y-axis direction. Specifically, the magnetic field generators 40-1 to 40-5 are formed so that the magnetic field detection element 30-1 is sandwiched between the magnetic field generator 40-1 and the magnetic field generator 40-2 in the Y-axis direction, the magnetic field detection element 30-2 is sandwiched between the magnetic field generator 40-2 and the magnetic field generator 40-3 in the Y-axis direction, the magnetic field detection element 30-3 is sandwiched between the magnetic field generator 40-3 and the magnetic field generator 40-4 in the Y-axis direction, and the magnetic field detection element 30-4 is sandwiched between the magnetic field generator 40-4 and the magnetic field generator 40-5 in the Y-axis direction.

[0031] Next, as shown in FIG. 2D, the magnetic field generators 40-1 to 40-5 are selectively irradiated with a laser beam LR to heat each of the magnetic field generators 40-1 to 40-5. In this case, for example, a mask having a plurality of openings in the XY plane corresponding only to the positions of the magnetic field generators 40-1 to 40-5 may be used for selective irradiation with the laser beam LR. After each of the magnetic field generators 40-1 to 40-5 has been heated by irradiation with the laser beam LR, a magnetic field EM is applied to the magnetic field generators 40-1 to 40-5 in, for example, the +Y direction, thereby magnetizing the magnetic field generators 40-1 to 40-5. The direction of the magnetic field EM is aligned with, for example, the +Y direction. This fixes the magnetization directions M40-1 to M40-5 of the ferromagnetic layers 42 of the magnetic field generators 40-1 to 40-5 to approximately the +Y direction. The intensity of the laser LR irradiated when fixing the magnetization directions M40-1 to M40-5 is preferably smaller than the intensity of the laser irradiated when fixing the magnetization direction of the magnetization fixed layer 32 of the magnetic field detection element 30. Furthermore, the magnetization process of each ferromagnetic layer 42 of the magnetic field generators 40-1 to 40-5 may be performed individually rather than all at once.

[0032] After the ferromagnetic layers 42 of the plurality of magnetic field generators 40 have been magnetized, the upper electrode 62 and the upper magnetic yoke 50 are formed in this order, thereby completing the magnetic sensor 1.

[0033] [Action and effect of magnetic sensor 1] As described above, in the magnetic sensor 1 according to this embodiment, the magnetization directions M40 (M40-1 to M40-5) of the multiple magnetic field generators 40 (40-1 to 40-5) aligned in the Y-axis direction, which is the extension direction of the lower magnetic yoke 20, are inclined at an angle of less than 45° with respect to the Y-axis direction, and in particular, the magnetization directions M40 (M40-1 to M40-5) are made to substantially coincide with the Y-axis direction. Therefore, despite its small size, it is possible to accurately detect the strength of a magnetic field to be detected in a predetermined direction.

[0034] Furthermore, in the magnetic sensor 1 of this embodiment, the lower magnetic yoke 20 is provided adjacent to the multiple magnetic field detection elements 30 in the X-axis direction, so that the magnetic field lines ML of the magnetic field to be detected that enter the magnetic sensor 1 in the Z-axis direction can be deflected in the X-axis direction and enter the multiple magnetic field detection elements 30. As a result, the multiple magnetic field detection elements 30 that are sensitive in the XY plane can detect the intensity of the magnetic field to be detected in the Z-axis direction. In the magnetic sensor 1 of this embodiment, as shown in FIG. 1B, the distance D12 between the multiple magnetic field generators 40 lined up in the Y-axis direction is shorter than the length L20 of the lower magnetic yoke 20 in the Y-axis direction. Therefore, by applying a magnetic field EM along a certain direction (the +Y direction in this embodiment) to multiple magnetic field generators 40 (40-1 to 40-5) arranged in the Y-axis direction while heating the multiple magnetic field generators 40 (40-1 to 40-5) by laser irradiation, it is possible to align the magnetization directions M40 (M40-1 to M40-5) of the multiple magnetic field generators 40 (40-1 to 40-5) approximately in the +Y direction, even if the magnetization process of the multiple magnetic field generators 40 (40-1 to 40-5) is performed all at once.

[0035] 3, if the length L20 of the lower magnetic yoke 20 in the Y-axis direction is equal to or less than the distance D12 between the magnetic field generators 40 arranged in the Y-axis direction, and the magnetic field generators 40 (40-1 to 40-5) are magnetized simultaneously, the magnetization direction M40 of the ferromagnetic layer 42 of each of the magnetic field generators 40 will likely be tilted by 45° or more from the +Y direction. If the magnetization direction M40 is tilted by 45° or more from the +Y direction, the initial magnetization direction of the magnetization free layer 34 of each of the adjacent magnetic field detection elements 30 will also be tilted by 45° or more from the +Y direction. This is because the magnetic field generators 40 apply a bias magnetic field to the magnetic field detection elements 30 in a direction different from the +Y direction. For example, suppose that the ferromagnetic layers 42 of multiple magnetic field generators 40 are magnetized by irradiating the multiple magnetic field generators 40 with a laser beam while a magnetic field in the +Y direction is applied. In this case, due to the presence of the lower magnetic yoke 20, the angle of the magnetization directions M40-1 and M40-5 of the magnetic field generators 40-1 and 40-5 located near both end edges 20T1 and 20T2 of the lower magnetic yoke 20 with respect to the +Y direction tends to be larger than 45°. In this case, the initial magnetization M34 of the magnetization-free layers 34 of the magnetic field detection elements 30-1 and 30-4 located near both end edges 20T1 and 20T2 of the lower magnetic yoke 20 is significantly tilted from the +Y direction. This causes an error in the electrical resistance of the magnetic field detection elements 30-1 and 30-5 when the magnetic field to be detected is applied. As a result, an error occurs in the overall electrical resistance value of the plurality of magnetic field detection elements 30 (30-1 to 30-4) connected in series that constitute the magnetic sensor 1.

[0036] In the manufacturing method of the magnetic sensor 1 of this embodiment, the distance D12 between the multiple magnetic field generators 40 arranged in the Y-axis direction is set to be smaller than the length L20 of the lower magnetic yoke 20 in the Y-axis direction. The multiple magnetic field generators 40 are simultaneously subjected to a heat treatment while being subjected to a magnetic field EM in the same direction (e.g., the +Y direction), thereby magnetizing the ferromagnetic layer 42 of each of the multiple magnetic field generators 40. This allows the magnetization direction M40 (M40-1 to M40-5) of the ferromagnetic layer 42 of each of the multiple magnetic field generators 40 to approach the +Y direction. With the magnetic sensor 1 of this embodiment manufactured in this manner, the magnetization direction M40 (M40-1 to M40-5) of the multiple magnetic field generators 40 is kept at an angle of less than 45° with respect to the +Y direction, thereby reducing errors in the electrical resistance value of the magnetic field detection element 30 when a magnetic field to be detected is applied. As a result, the strength of the magnetic field to be detected reaching the magnetic sensor 1 can be accurately detected.

[0037] Furthermore, in the magnetic sensor 1 of this embodiment, if the length L30 of the magnetic field detection element 30 in the Y-axis direction is made shorter than the length L40 of the magnetic field generator 40 in the Y-axis direction, the linearity of the change in electrical resistance value in the magnetic field detection element 30 in response to changes in the strength of the magnetic field to be detected is improved.

[0038] Furthermore, in the magnetic sensor 1 of this embodiment, if the width W30 of the magnetic field detection element 30 in the X-axis direction is made narrower than the width W40 of the magnetic field generator 40 in the X-axis direction, a highly uniform bias magnetic field can be applied to the entire magnetic field detection element 30. As a result, the direction of the magnetization M34 of the magnetization free layer 34 of the magnetic field detection element 30 becomes more stable.

[0039] Furthermore, in the magnetic sensor 1 of this embodiment, if a magnetic shield made of a soft magnetic material such as permalloy (NiFe) is used as the substrate 10, it is possible to effectively prevent unnecessary disturbance magnetic fields from being applied to the magnetic field detection element 30. As a result, the detection accuracy of the magnetic field to be detected by the magnetic field detection element 30 is further improved.

[0040] <2. Second embodiment> [Configuration of magnetic field detection device 100] Next, a configuration of a magnetic field detection device 100 according to a second embodiment of the present disclosure will be described with reference to Fig. 4. Fig. 4 is a schematic plan view illustrating an example of the planar configuration of the magnetic field detection device 100.

[0041] As shown in FIG. 4, the magnetic field detection device 100 includes one support substrate 101 and a plurality of chips CP mounted on the support substrate 101. The configuration example shown in FIG. 4 illustrates four chips CP1 to CP4. The four chips CP1 to CP4 of the magnetic field detection device 100 configure the magnetic field detection circuit 102 shown in FIG. 5. FIG. 5 is a circuit diagram illustrating an example of the circuit configuration of the magnetic field detection circuit 102 included in the magnetic field detection device 100. However, the present disclosure is not limited to the configuration example of FIG. 4, and the number of chips CP mounted on the support substrate 101 can be selected arbitrarily.

[0042] Each of the chips CP has a pair of magnetic sensors 1A and 1B. The pair of magnetic sensors 1A and 1B has the same configuration as the magnetic sensor 1 described in the first embodiment, for example. However, in each of the chips CP, the pair of magnetic sensors 1A and 1B share a substrate 10 and an upper magnetic yoke 50. That is, one substrate 10 is provided with lower magnetic yokes 20A and 20B, multiple magnetic field detection elements 30A and 30B, multiple magnetic field generators 40A and 40B, and one upper magnetic yoke 50. The lower magnetic yoke 20A, the multiple magnetic field detection elements 30A, and the multiple magnetic field generators 40A are components of the magnetic sensor 1A. The lower magnetic yoke 20B, the multiple magnetic field detection elements 30B, and the multiple magnetic field generators 40B are components of the magnetic sensor 1B. The substrate 10 and the upper magnetic yoke 50 are components of each of the pair of magnetic sensors 1A and 1B. In each of the chips CP, the magnetic field detection elements 30A, 30B included in each of the chips CP are all directly connected to form a variable resistor, which is a device whose electrical resistance changes depending on the strength of the magnetic field component in a predetermined direction of the applied external magnetic field. In Figure 4, in order to improve visibility, lower magnetic yokes 20A, 20B, multiple magnetic field detection elements 30A, 30B, multiple magnetic field generators 40A, 40B, and one upper magnetic yoke 50 are shown on one substrate 10, and other components are omitted.

[0043] In the chips CP1 and CP4, the magnetization directions M40 of the multiple magnetic field generators 40A and 40B are preferably all aligned along the +Y direction. Therefore, the initial magnetization M34 of the magnetization free layers 34 of the multiple magnetic field detection elements 30A and 30B in the chips CP1 and CP4 are preferably all aligned along the +Y direction. In contrast, in the chips CP2 and CP3, the magnetization directions M40 of the multiple magnetic field generators 40A and 40B are preferably all aligned along the -Y direction. Therefore, the initial magnetization M34 of the magnetization free layers 34 of the multiple magnetic field detection elements 30A and 30B in the chips CP2 and CP3 are preferably all aligned along the -Y direction.

[0044] In addition, in the chips CP1 and CP3, the directions of the magnetization M32 of the magnetization fixed layers 32 of the plurality of magnetic field detection elements 30A and 30B are fixed, for example, in the +X direction and the −X direction, respectively. Specifically, as shown in FIG. 4, in the chips CP1 and CP3, the directions of the magnetization M32 of the magnetization fixed layers 32 of the plurality of magnetic field detection elements 30A of the magnetic sensor 1A are fixed in the +X direction, and the directions of the magnetization M32 of the magnetization fixed layers 32 of the plurality of magnetic field detection elements 30B of the magnetic sensor 1B are fixed in the −X direction. In this case, in the chips CP2 and CP4, the directions of the magnetization M32 of the magnetization fixed layers 32 of the plurality of magnetic field detection elements 30A and 30B are fixed, for example, in the −X direction and the +X direction, respectively. Specifically, as shown in FIG. 4, in chips CP2 and CP4, the direction of magnetization M32 of each magnetization fixed layer 32 of the multiple magnetic field detection elements 30A of magnetic sensor 1A is fixed in the −X direction, and the direction of magnetization M32 of each magnetization fixed layer 32 of the multiple magnetic field detection elements 30B of magnetic sensor 1B is fixed in the +X direction.

[0045] 5, R1 represents a variable resistor as an assembly of the multiple magnetic field detection elements 30A and 30B in chip CP1. Similarly, in the magnetic field detection circuit 102, R2 represents a variable resistor as an assembly of the multiple magnetic field detection elements 30A and 30B in chip CP2, R3 represents a variable resistor as an assembly of the multiple magnetic field detection elements 30A and 30B in chip CP3, and R4 represents a variable resistor as an assembly of the multiple magnetic field detection elements 30A and 30B in chip CP4.

[0046] The magnetic field detection device 100 detects the intensity of the magnetic field to be detected, which is deflected along the X-axis direction by the lower magnetic yoke 20 and the upper magnetic yoke 50 and guided to the magnetic field detection elements 30. Here, it is assumed that the magnetic field to be detected is applied in the +Z direction to all the magnetic field detection elements 30 in each of the chips CP1 to CP4. The magnetic field detection device 100 generates a detection signal according to the intensity of the magnetic field to be detected.

[0047] As shown in FIG. 5, the magnetic field detection circuit 102 of the magnetic field detection device 100 forms a Wheatstone bridge. The magnetic field detection circuit 102 includes a power supply port V, a ground port G, two output ports E1 and E2, a first variable resistor R1 and a second variable resistor R2 connected in series, and a third variable resistor R3 and a fourth variable resistor R4 connected in series. A first end of the first variable resistor R1 and a first end of the fourth variable resistor R4 are each connected to the power supply port V. A second end of the first variable resistor R1 is connected to a first end of the second variable resistor R2 and the output port E2, respectively. A second end of the fourth variable resistor R4 is connected to a first end of the third variable resistor R3 and the output port E1, respectively. A second end of the second variable resistor R2 and a second end of the third variable resistor R3 are each connected to the ground port G. A power supply voltage of a predetermined magnitude is applied to the power supply port V. The ground port G is connected to ground. Each of the output ports E1 and E2 is connected to an external control unit 70. The control unit 70 has a circuit including, for example, a CPU (Central Processing Unit) which is an arithmetic processing device, a ROM (Read Only Memory) which is a memory element for storing programs used by the CPU, calculation parameters, etc., and a RAM (Random Access Memory) which is a memory element for temporarily storing parameters that change as the CPU executes.

[0048] [Actions and Effects of the Magnetic Field Detection Device 100] The magnetic field detection device 100 outputs an output voltage that monotonically increases or decreases depending on the strength of the magnetic field to be detected. When the strength of the magnetic field to be detected changes, the resistances of the first variable resistor R1 and the third variable resistor R3 increase while the resistances of the second variable resistor R2 and the fourth variable resistor R4 decrease. Alternatively, the resistances of the first variable resistor R1 and the third variable resistor R3 decrease while the resistances of the second variable resistor R2 and the fourth variable resistor R4 increase. This changes the potential difference between the output ports E1 and E2 shown in FIG. 5. The magnetic field detection device 100 generates a detection signal that depends on the potential difference between the output ports E1 and E2. The detection signal corresponds to the strength of the magnetic field to be detected. Specifically, the magnetic field detection device 100 exhibits behavior similar to that shown in the characteristic diagram of FIG. 6. The horizontal axis in FIG. 6 represents the strength of the magnetic field to be detected applied to the magnetic field detection element 30 in the Z-axis direction, and the vertical axis in FIG. 6 represents the output voltage. In FIG. 6, the strength of the magnetic field to be detected in the +Z direction is defined as positive, and the strength of the magnetic field to be detected in the -Z direction is defined as negative. As shown by the solid line in FIG. 6, the output voltage of the magnetic field detection device 100 changes almost linearly depending on the strength of the applied magnetic field to be detected. That is, the magnetic field detection device 100 exhibits extremely high linearity in the relationship between the strength of the magnetic field to be detected and the output voltage. Note that the dashed line in FIG. 6 represents the relationship between the strength of the magnetic field to be detected and the output voltage when the magnetic field detection device 100 is equipped with the magnetic sensor 1001 shown in FIG. 3 as a reference example instead of the magnetic sensors 1A and 1B. In the magnetic sensor 1001, the magnetization direction M40 of some of the magnetic field generators 40 is significantly inclined from the +Y direction, so the linearity of the relationship between the strength of the magnetic field to be detected and the output voltage is degraded.

[0049] According to the magnetic field detection device 100 equipped with the magnetic field detection circuit 102 configured as described above, since it is equipped with multiple chips CP each having magnetic sensors 1A and 1B, the strength of the magnetic field to be detected applied to the magnetic field detection device 100 can be detected with high accuracy.

[0050] <3. Third Embodiment> [Magnetic Compass 200 Configuration] Next, with reference to FIG. 7 and FIGS. 8A to 8C, the configuration of a magnetic compass 200 according to a third embodiment of the present disclosure will be described. FIG. 7 is a perspective view illustrating the external appearance of the magnetic compass 200. The magnetic compass 200 includes a chip 202 including magnetic sensors 3X, 3Y, and 3Z and a support substrate 201 supporting the chip 202. The magnetic compass 200 is built into a mobile information terminal device such as a smartphone. The magnetic sensor 3Z has substantially the same configuration as the magnetic sensor 1 described in the first embodiment. The magnetic sensors 3X ​​and 3Y each have the configuration of the magnetic sensor 2 shown in FIGS. 8A to 8C. FIG. 8A is a plan view illustrating an example of the planar configuration of the magnetic sensor 2, and corresponds to FIG. 1A illustrating the example of the planar configuration of the magnetic sensor 1 described in the first embodiment. FIG. 8B is a cross-sectional view illustrating an example of the cross-sectional configuration of the magnetic sensor 2 taken along the VIIIB-VIIIB line in FIG. 8A. FIG. 8C is a cross-sectional view illustrating an example of the cross-sectional configuration of the magnetic sensor 2 taken along the line VIIIC-VIIIC in FIG. 8A. FIGS. 8B and 8C correspond to FIGS. 1B and 1C, respectively, illustrating an example of the cross-sectional configuration of the magnetic sensor 1 described in the first embodiment. The magnetic sensor 2 has a first magnetic yoke 21 instead of the lower magnetic yoke 20 and a second magnetic yoke 51 instead of the upper magnetic yoke 50. In the magnetic sensor 2, the first magnetic yoke 21 and the second magnetic yoke 51 are provided on the same level as the magnetic field detection element 30 and the magnetic field generator 40. Specifically, the first magnetic yoke 21, the second magnetic yoke 51, the magnetic field detection element 30, and the magnetic field generator 40 are all provided on the second level L2. Except for this point, the configuration of the magnetic sensor 2 is substantially the same as the configuration of the magnetic sensor 1. In the magnetic sensor 2, the distance D12 between the first edge T1 of the magnetic field generator 40-1 and the second edge T2 of the magnetic field generator 40-7 is equal to or greater than the length L21 of the first magnetic yoke 21 in the Y-axis direction and equal to or greater than the length L51 of the second magnetic yoke 51 in the Y-axis direction. That is, the length L21 of the first magnetic yoke 21 and the length L51 of the second magnetic yoke 51 are equal to or less than the distance D12. The length L21 is the length from the edge 21T1 on the +Y side of the first magnetic yoke 21 to the edge 21T2 on the -Y side of the first magnetic yoke 21.Length L51 is the length from edge 51T1 on the +Y side of second magnetic yoke 51 to edge 51T2 on the -Y side of second magnetic yoke 51. Magnetic sensors 3X, 3Y, and 3Z detect magnetic fields in different directions. Specifically, magnetic compass 200 is configured such that magnetic sensors 3X, 3Y, and 3Z detect three mutually orthogonal components of an external magnetic field, for example, the X-axis component, Y-axis component, and Z-axis component of the geomagnetic field, respectively.

[0051] [Magnetic Compass 200 Functions] Magnetic compass 200 includes magnetic sensor 3Z having substantially the same configuration as magnetic sensor 1 described in the first embodiment above, and magnetic sensors 3X ​​and 3Y having the configuration of magnetic sensor 2 shown in Figures 8A to 8C. Therefore, each of magnetic sensors 3X, 3Y, and 3Z can output output signals with good linearity in response to the X-axis component, Y-axis component, and Z-axis component of the geomagnetic field. Therefore, magnetic compass 200 can achieve higher detection resolution and, ultimately, high reproducibility in magnetic field measurements.

[0052] <4. Fourth embodiment> [Configuration of imaging device 300] Next, with reference to FIG. 9, a configuration of an imaging device 300 according to a fourth embodiment of the present disclosure will be described.

[0053] Fig. 9 is a perspective view illustrating an example of the overall configuration of the imaging device 300. Note that the imaging device 300 illustrated in Fig. 9 is merely an example, and in this embodiment, the components constituting the imaging device 300, as well as their dimensions, shapes, and arrangement positions, are not limited to those illustrated in Fig. 9.

[0054] The imaging device 300 constitutes, for example, a part of a camera for a smartphone equipped with an autofocus mechanism and an optical image stabilization mechanism. The imaging device 300 includes, for example, an image sensor 310 that acquires an image using a CMOS or the like, and a lens module 320 that guides light from a subject to the image sensor 310.

[0055] [Configuration of lens module 320] The lens module 320 includes a position detection device 350, a driving device 303, a lens 305, a housing 306, and a substrate 307. The position detection device 350 includes the magnetic sensor 1 and magnet 5 described in the first embodiment above. The magnetic sensor 1 is fixed to the substrate 307. The magnet 5 is provided above the magnetic sensor 1 (at a position in the +Z direction). The magnet 5 is magnetized in the Z-axis direction and applies a magnetic field with, for example, a component in the -Z direction to the magnetic sensor 1. The magnet 5 is configured to move integrally with the lens 305. The relative position of the magnetic sensor 1 and the magnet 5 changes along the Z-axis direction. When the relative position of the magnetic sensor 1 and the magnet 5 changes, the detection signal of the magnetic sensor 1 changes.

[0056] The position detection device 350 detects the position of the lens 305 when performing automatic focusing or image stabilization. The drive device 303 moves the lens 305. The housing 306 houses the position detection device 350, the drive device 303, and the lens 305 and protects them. The board 307 supports the position detection device 350, the drive device 303, the lens 305, and the housing 306.

[0057] Here, as shown in FIG. 9, the +U direction and the +V direction are defined. The +U direction is a direction rotated by −45° from the +X direction toward the −Y direction. The +V direction is a direction rotated by 45° from the +X direction toward the +Y direction. The +U direction and the +V direction are each orthogonal to the +Z direction. In the lens module 320, the direction perpendicular to the upper surface 307a of the substrate 307 and extending from the substrate 307 toward the lens 305 is defined as the +Z direction. Both the +U direction and the +V direction are directions parallel to the upper surface 307a of the substrate 307. The direction opposite to the +U direction is defined as the −U direction, and the direction opposite to the +V direction is defined as the −V direction.

[0058] Lens 305 is disposed above upper surface 307a of substrate 307 in an orientation such that the optical axis direction of lens 305 coincides with a direction parallel to the Z-axis direction. Substrate 307 also has an opening that passes light that has passed through lens 305. Lens module 320 is aligned with image sensor 310 so that light that has passed through lens 305 and the opening of substrate 307 is incident on image sensor 310.

[0059] Driving device 303 includes magnets 331A, 331B, 332A, 332B, 333A, 333B, 334A, and 334B, and coils 341, 342, 343, 344, 345, and 346. Magnet 331A is disposed in a position in the -V direction when viewed from lens 305. Magnet 332A is disposed in a position in the +V direction when viewed from lens 305. Magnet 333A is disposed in a position in the -U direction when viewed from lens 305. Magnet 334A is disposed in a position in the +U direction when viewed from lens 305. Magnets 331B, 332B, 333B, and 334B are disposed above (on the +Z side of) magnets 331A, 332A, 333A, and 334A, respectively.

[0060] Magnets 331A, 331B, 332A, and 332B each have a rectangular parallelepiped shape elongated in the U-axis direction. Magnets 333A, 333B, 334A, and 334B each have a rectangular parallelepiped shape elongated in the V-axis direction. The magnetization direction of magnets 331A and 332B is the +V direction. The magnetization direction of magnets 331B and 332A is the -V direction. The magnetization direction of magnets 333A and 334B is the +U direction. The magnetization direction of magnets 333B and 334A is the -U direction.

[0061] Coil 341 is disposed between magnet 331A and substrate 307. Coil 342 is disposed between magnet 332A and substrate 307. Coil 343 is disposed between magnet 333A and substrate 307. Coil 344 is disposed between magnet 334A and substrate 307. Coil 345 is disposed between magnets 331A, 331B and lens 305. Coil 346 is disposed between magnets 332A, 332B and lens 305. Coils 341, 342, 343, and 344 are fixed to substrate 307. Coils 345 and 346 are provided to be movable along the Z-axis direction integrally with lens 305.

[0062] A magnetic field generated mainly by magnet 331A is applied to coil 341. A magnetic field generated mainly by magnet 332A is applied to coil 342. A magnetic field generated mainly by magnet 333A is applied to coil 343. A magnetic field generated mainly by magnet 334A is applied to coil 344.

[0063] Coil 345 has a portion to which the +V directional component of the magnetic field generated mainly from magnet 331A is applied, and a portion to which the −V directional component of the magnetic field generated mainly from magnet 331B is applied. Coil 346 has a portion to which the −V directional component of the magnetic field generated mainly from magnet 332A is applied, and a portion to which the +V directional component of the magnetic field generated mainly from magnet 332B is applied.

[0064] The driving device 303 further includes a magnetic sensor 1A fixed to the substrate 307 inside the coil 341, and a magnetic sensor 1B fixed to the substrate 307 inside the coil 344. The magnetic sensors 1A and 1B are used to change the position of the lens 305 to reduce the effects of camera shake. The magnetic sensor 1A detects the magnetic field generated by the magnet 331A and generates a signal corresponding to the position of the magnet 331A. The magnetic sensor 1B detects the magnetic field generated by the magnet 334A and generates a signal corresponding to the position of the magnet 334A. The magnetic sensor 1 described in the first embodiment can be used as the magnetic sensors 1A and 1B.

[0065] The optical image stabilization mechanism is configured to detect camera shake using, for example, a gyro sensor. Note that a sensor such as a gyro sensor may be provided external to the imaging device 300. When the optical image stabilization mechanism detects camera shake, the control unit 80 controls the drive device 303 to change the relative position of the lens 305 with respect to the substrate 307 in accordance with the type of camera shake. This stabilizes the absolute position of the lens 305, thereby reducing the effects of camera shake. Note that the relative position of the lens 305 with respect to the substrate 307 changes in a direction parallel to the U direction or a direction parallel to the V direction in accordance with the type of camera shake.

[0066] [Operation of imaging device 300] The operation of the imaging device 300 is controlled by a control unit 80 provided outside the imaging device 300. The control unit 80 has a circuit configured with, for example, a CPU (Central Processing Unit) which is an arithmetic processing device, a ROM (Read Only Memory) which is a storage element that stores programs used by the CPU, calculation parameters, etc., and a RAM (Random Access Memory) which is a storage element that temporarily stores parameters, etc. that change appropriately during execution of the CPU.

[0067] The autofocus mechanism is configured to detect whether a subject is in focus using, for example, an image sensor 310 or an autofocus sensor. The control unit 80 controls the drive unit 303 to change the position of the lens 305 relative to the substrate 307 along the Z axis so that the subject is in focus. This allows automatic focusing on the subject. To move the position of the lens 305 relative to the substrate 307, for example, along the +Z direction, the control unit 80 applies currents in a predetermined direction to each of the coils 345 and 346. These currents, along with the magnetic fields generated by the magnets 331A, 331B, 332A, and 332B, act on the coils 345 and 346 in the +Z direction. As a result, the coils 345 and 346 move together with the lens 305 in the +Z direction relative to the substrate 307. When the relative position of lens 305 with respect to substrate 307 is to be moved in the −Z direction, control unit 80 causes current to flow through coils 345 and 346 in the opposite direction to when moving in the +Z direction.

[0068] Next, the operation of drive device 303 related to the optical image stabilization mechanism will be described. When control unit 80 applies current to coils 341 and 342, the magnetic fields generated by magnets 331A and 332A interact with the magnetic fields generated by coils 341 and 342, causing magnets 331A and 332A to move together with lens 305 in a direction parallel to the V-axis direction relative to substrate 307. When control unit 80 applies current to coils 343 and 344, the magnetic fields generated by magnets 333A and 334A interact with the magnetic fields generated by coils 343 and 344, causing magnets 333A and 334A to move together with lens 305 in a direction parallel to the U-axis direction relative to substrate 307. Control unit 80 detects the position of lens 305 by measuring signals corresponding to the positions of magnets 331A and 334A, generated by magnetic sensors 1A and 1B.

[0069] [Operation and effect of the imaging device 300] The imaging device 300 is provided with a position detection device 350 having the magnetic sensor 1 of the first embodiment, and therefore can accurately detect the amount of change (displacement) in the position of the magnet 5, which moves integrally with the lens 305. This allows the imaging device 300 to perform highly accurate focusing. Furthermore, the imaging device 300 is provided with a drive device 303 having magnetic sensors 1A and 1B to which the magnetic sensor 1 of the first embodiment is applied, and therefore can accurately detect the amount of change (displacement) in the position of the magnets 331A and 334A, which move integrally with the lens 305. This allows the imaging device 300 to perform highly accurate optical image stabilization.

[0070] The imaging device 300 may be equipped with only one of the autofocus mechanism and the optical image stabilization mechanism.

[0071] <7. Other Modifications> Although the present disclosure has been described above using several embodiments, the present disclosure is not limited to these embodiments and various modifications are possible. For example, in the first embodiment, an exchange-coupled bias structure formed by exchange-coupling an antiferromagnetic layer and a ferromagnetic layer was used as an example of a magnetic field generator that applies a bias magnetic field to a magnetic field detection element. However, the magnetic field generator of the present disclosure can take other forms. The magnetic field generator of the present disclosure may be, for example, a permanent magnet. Examples of materials that can be used for the permanent magnet include neodymium-based magnetic materials such as NdFeB and rare-earth magnetic materials such as SmCo.

[0072] In the magnetic sensor of the present disclosure, a magnetic shield may also be provided above the upper magnetic yoke.

[0073] Furthermore, in the magnetic field detection device 100 of the second embodiment, a pair of magnetic sensors 1A, 1B in each of the multiple chips CP share the upper magnetic yoke 50, but the present disclosure is not limited to this. In the magnetic field detection device of the present disclosure, a pair of magnetic sensors in each of the multiple chips may share the lower magnetic yoke. Alternatively, the magnetic field detection device of the present disclosure may have a structure in which the pair of magnetic sensors 1A, 1B do not share components with each other. Furthermore, in the magnetic field detection device 100 of the second embodiment, a portion of the multiple magnetic field generators 40A constituting the magnetic sensor 1A and a portion of the multiple magnetic field generators 40B constituting the magnetic sensor 1B may be magnetized collectively.

[0074] Furthermore, the dimensions of each component and the layout of each component are examples and are not intended to be limiting.

[0075] Furthermore, the position detection device of the present disclosure is not limited to a device for detecting the position of a lens, but may also be a device for detecting the spatial position of an object other than a lens. [Explanation of symbols]

[0076] 1...magnetic sensor, 10...substrate, 20...lower magnetic yoke, 21...first magnetic yoke, 30...magnetic field detection element, 31...antiferromagnetic layer, 32...magnetization fixed layer, 33...gap layer, 34...magnetization free layer, 40...magnetic field generator, 41...antiferromagnetic layer, 42...ferromagnetic layer, 50...upper magnetic yoke, 51...second magnetic yoke, 61...lower electrode, 62...upper electrode, 100...magnetic field detection device, 101...support substrate, 102...circuit, 200...magnetic compass, 300, 300A...imaging device, L1...first layer, L2...second layer, Z1 to Z3...insulating layers.

Claims

1. a first layer including a magnetic yoke, and a second layer including a magnetic field detection element and a plurality of magnetic field generators that apply magnetic fields to the magnetic field detection element and are discretely arranged along a first axis direction, the second layer being stacked in this order in a second axis direction that intersects with the first axis direction; the magnetic field detection element is sandwiched between two magnetic field generators selected from the plurality of magnetic field generators in the first axial direction, the magnetic yoke extends in the first axis direction and is adjacent to the magnetic field detection element in a third axis direction that intersects both the first axis direction and the second axis direction in a plan view seen in the second axis direction, the plurality of magnetic field generators arranged in the first axial direction include a first magnetic field generator arranged at a first end in the first axial direction and a second magnetic field generator arranged at a second end opposite to the first end in the first axial direction, a distance between a first end edge of the first magnetic field generator located farthest from the second magnetic field generator and a second end edge of the second magnetic field generator located farthest from the first magnetic field generator is shorter than a length of the magnetic yoke in the second axial direction; Magnetic sensor.

2. The plurality of magnetic field generators are exchange coupling bias structures including a ferromagnetic body and an antiferromagnetic body that is in contact with the ferromagnetic body and exchange coupled to the ferromagnetic body. The magnetic sensor according to claim 1 .

3. The length of the magnetic field detection element in the second axial direction is shorter than the length of the magnetic field generators in the second axial direction. The magnetic sensor according to claim 1 .

4. The width of the magnetic field detection element in the third axial direction is narrower than the width of each of the plurality of magnetic field generators in the third axial direction. The magnetic sensor according to claim 1 .

5. The laminated structure further includes a support. The magnetic sensor according to claim 1 .

6. The support is a magnetic shield. The magnetic sensor according to claim 1 .

7. The magnetic field detection element is a magnetoresistive element including a laminate in which a magnetization fixed layer, a gap layer, and a magnetization free layer are laminated in this order. The magnetic sensor according to claim 1 .

8. a magnetic field detection element; a plurality of magnetic field generators that apply a magnetic field to the magnetic field detection elements and are discretely arranged along a first axis direction; and the plurality of magnetic field generators are exchange coupling bias structures including a ferromagnetic body and an antiferromagnetic body that is in contact with the ferromagnetic body and exchange coupled to the ferromagnetic body, the magnetic field detection element is sandwiched between two magnetic field generators selected from the plurality of magnetic field generators in the first axial direction, the magnetic yoke extends in the first axis direction and is adjacent to the magnetic field detection element in a third axis direction that intersects both the first axis direction and the second axis direction in a plan view seen in the second axis direction, the plurality of magnetic field generators arranged in the first axial direction include a first magnetic field generator arranged at a first end in the first axial direction and a second magnetic field generator arranged at a second end opposite to the first end in the first axial direction, a distance between a first end edge of the first magnetic field generator located farthest from the second magnetic field generator and a second end edge of the second magnetic field generator located farthest from the first magnetic field generator is shorter than a length of the magnetic yoke in the second axial direction; Magnetic sensor.

9. A magnetic field detection device comprising the magnetic sensor according to any one of claims 1 to 8.

10. A position detection device comprising the magnetic sensor according to any one of claims 1 to 8.

11. A lens module comprising the magnetic sensor according to claim 1 .

12. An imaging device comprising the lens module according to claim 11.

Images