Magnetic sensor and magnetic detection system

Abstract

The present invention suppresses a reduction in a detection magnetic field. A magnetoresistance pattern portion (31) of a first magnetoresistance effect element (111) and the magnetoresistance pattern portion (31) of a third magnetoresistance effect element (121) overlap in a plan view from a first direction (D1). The magnetoresistance pattern portion (31) of a second magnetoresistance effect element (112) and the magnetoresistance pattern portion (31) of a fourth magnetoresistance effect element (122) overlap in a plan view from the first direction (D1). A magnetoresistance pattern portion (32) of a fifth magnetoresistance effect element (211) and the magnetoresistance pattern portion (32) of a seventh magnetoresistance effect element (221) overlap in a plan view from a second direction (D2). The magnetoresistance pattern portion (32) of a sixth magnetoresistance effect element (212) and the magnetoresistance pattern portion (32) of an eighth magnetoresistance effect element (222) overlap in a plan view from the second direction (D2).

Description

Magnetic sensor and magnetic detection system

[0001] The present disclosure relates generally to magnetic sensors and magnetic sensing systems, and more particularly to a magnetic sensor including at least one bias magnet, and a magnetic sensing system including the magnetic sensor.

[0002] Patent Document 1 describes a rotation angle detection sensor (magnetic sensor) that detects the rotation angle of a rotating shaft. The rotation angle detection sensor described in Patent Document 1 has at least two pairs of GMR (Giant Magnet Resistive) elements, each having a free magnetic layer and a pinned magnetic layer, provided on a substrate. In addition, in the rotation angle detection sensor described in Patent Document 1, each pair of GMR elements is arranged to face each other across the rotation axis of the magnet's rotating shaft, and the magnetization directions of the pinned magnetic layers are opposite to each other.

[0003] Japanese Patent Application Laid-Open No. 2002-303536

[0004] In the rotation angle detection sensor (magnetic sensor) described in Patent Document 1, the two GMR elements in each pair are arranged at different positions in the X-axis direction or the Y-axis direction, which may result in a decrease in detection accuracy.

[0005] An object of the present disclosure is to provide a magnetic sensor and a magnetic detection system that can suppress a decrease in detection accuracy.

[0006] A magnetic sensor according to one aspect of the present disclosure includes at least one bias magnet, a first full-bridge circuit, a second full-bridge circuit, and a substrate. The at least one bias magnet generates a bias magnetic field along a positive direction of the X-axis, a bias magnetic field along a negative direction of the X-axis, a bias magnetic field along a positive direction of the Y-axis, which is an axis perpendicular to the X-axis, and a bias magnetic field along the negative direction of the Y-axis. The substrate supports the at least one bias magnet, the first full-bridge circuit, and the second full-bridge circuit. The first full-bridge circuit includes a first series circuit and a second series circuit. The first series circuit includes first and second magnetoresistance effect elements connected in series to each other and detecting a magnetic field along the X-axis. The second series circuit includes third and fourth magnetoresistance effect elements connected in series to each other and detecting a magnetic field along the X-axis. The first and second series circuits are connected in parallel to each other. The second full-bridge circuit includes a third and fourth series circuit. The third series circuit includes a fifth magnetoresistive element and a sixth magnetoresistive element connected in series to detect a magnetic field along the Y-axis. The fourth series circuit includes a seventh magnetoresistive element and an eighth magnetoresistive element connected in series to detect a magnetic field along the Y-axis. The third series circuit and the fourth series circuit are connected in parallel to each other. A bias magnetic field is applied to the first magnetoresistive element and the third magnetoresistive element in the positive direction of the X-axis. A bias magnetic field is applied to the second magnetoresistive element and the fourth magnetoresistive element in the negative direction of the X-axis. A bias magnetic field is applied to the fifth magnetoresistive element and the seventh magnetoresistive element in the positive direction of the Y-axis. A bias magnetic field is applied to the sixth magnetoresistive element and the eighth magnetoresistive element in the negative direction of the Y-axis. Each of the first, second, third, fourth, fifth, sixth, seventh, and eighth magnetoresistive elements has a magnetoresistive pattern formed in a meandering shape, and the magnetoresistive pattern of the first magnetoresistive element and the magnetoresistive pattern of the third magnetoresistive element overlap in a plan view from a first direction in which the first and second magnetoresistive elements are aligned.The magnetoresistive pattern portion of the second magnetoresistive element and the magnetoresistive pattern portion of the fourth magnetoresistive element overlap when viewed from a first direction. The magnetoresistive pattern portion of the fifth magnetoresistive element and the magnetoresistive pattern portion of the seventh magnetoresistive element overlap when viewed from a second direction that is perpendicular to the first direction. The magnetoresistive pattern portion of the sixth magnetoresistive element and the magnetoresistive pattern portion of the eighth magnetoresistive element overlap when viewed from the second direction.

[0007] A magnetic detection system according to one aspect of the present disclosure includes the magnetic sensor of the above aspect and a processing circuit, wherein the processing circuit determines the direction of the magnetic field applied to the magnetic sensor based on the output signal of the magnetic sensor.

[0008] According to the magnetic sensor and magnetic detection system according to the above aspects of the present disclosure, it is possible to suppress a decrease in detection accuracy.

[0009] FIG. 1 is a plan view of a magnetic sensor according to an embodiment. FIG. 2 is a cross-sectional view of the magnetic sensor according to an embodiment. FIG. 3 is a schematic diagram showing a state in which the magnetic sensor according to an embodiment is used. FIG. 4 is an equivalent circuit diagram of a first full-bridge circuit of the magnetic sensor according to an embodiment. FIG. 5 is an equivalent circuit diagram of a second full-bridge circuit of the magnetic sensor according to an embodiment. FIG. 6 is an explanatory diagram showing an output signal of the magnetic sensor according to an embodiment. FIG. 7 is a layout diagram showing an example layout of magnetoresistive effect elements of the magnetic sensor according to an embodiment. FIG. 8 is a schematic diagram of the magnetic sensor according to an embodiment. FIG. 9 is a schematic diagram of a magnetic sensor according to a comparative example.

[0010] Hereinafter, magnetic sensors and magnetic detection systems according to embodiments will be described in detail with reference to the drawings. The drawings referred to in the following embodiments are schematic diagrams, and the sizes and thicknesses of the components in the drawings do not necessarily reflect the actual dimensions, and the size and thickness ratios between the components do not necessarily reflect the actual dimensional ratios.

[0011] (Embodiment) (1) Overview First, an overview of a magnetic sensor 100 and a magnetic detection system 200 according to an embodiment will be described with reference to FIG.

[0012] Fig. 1 is a plan view of a magnetic sensor 100 according to an embodiment. As shown in Fig. 1, the magnetic sensor 100 according to the embodiment includes at least one bias magnet 5, a first full-bridge circuit 1, a second full-bridge circuit 2, and a substrate 74 (see Fig. 2 described later). The at least one bias magnet 5 generates a bias magnetic field along the positive direction of the X-axis, a bias magnetic field along the negative direction of the X-axis, a bias magnetic field along the positive direction of the Y-axis, which is an axis perpendicular to the X-axis, and a bias magnetic field along the negative direction of the Y-axis. The substrate 74 holds the at least one bias magnet 5, the first full-bridge circuit 1, and the second full-bridge circuit 2.

[0013] The first full-bridge circuit 1 includes a first series circuit 11 and a second series circuit 12. The first series circuit 11 includes a first magnetoresistance effect element 111 and a second magnetoresistance effect element 112. The first magnetoresistance effect element 111 and the second magnetoresistance effect element 112 are connected in series to each other and detect a magnetic field along the X-axis. The second series circuit 12 includes a third magnetoresistance effect element 121 and a fourth magnetoresistance effect element 122. The third magnetoresistance effect element 121 and the fourth magnetoresistance effect element 122 are connected in series to each other and detect a magnetic field along the X-axis. The first series circuit 11 and the second series circuit 12 are connected in parallel to each other.

[0014] The second full-bridge circuit 2 includes a third series circuit 21 and a fourth series circuit 22. The third series circuit 21 includes a fifth magnetoresistance element 211 and a sixth magnetoresistance element 212. The fifth magnetoresistance element 211 and the sixth magnetoresistance element 212 are connected in series to each other and detect a magnetic field along the Y-axis. The fourth series circuit 22 includes a seventh magnetoresistance element 221 and an eighth magnetoresistance element 222. The seventh magnetoresistance element 221 and the eighth magnetoresistance element 222 are connected in series to each other and detect a magnetic field along the Y-axis. The third series circuit 21 and the fourth series circuit 22 are connected in parallel to each other.

[0015] A bias magnetic field along the positive direction of the X-axis is applied to the first magnetoresistance effect element 111 and the third magnetoresistance effect element 121. A bias magnetic field along the negative direction of the X-axis is applied to the second magnetoresistance effect element 112 and the fourth magnetoresistance effect element 122. A bias magnetic field along the positive direction of the Y-axis is applied to the fifth magnetoresistance effect element 211 and the seventh magnetoresistance effect element 221. A bias magnetic field along the negative direction of the Y-axis is applied to the sixth magnetoresistance effect element 212 and the eighth magnetoresistance effect element 222.

[0016] Each of the first magnetoresistance effect element 111, the second magnetoresistance effect element 112, the third magnetoresistance effect element 121, the fourth magnetoresistance effect element 122, the fifth magnetoresistance effect element 211, the sixth magnetoresistance effect element 212, the seventh magnetoresistance effect element 221 and the eighth magnetoresistance effect element 222 has a magnetoresistance pattern portion 31, 32 formed in a meander shape (see Figure 7 described below).

[0017] 7 is a layout diagram showing an example of the layout of the magnetoresistive elements of the magnetic sensor 100 according to the embodiment. The magnetoresistive pattern 31 of the first magnetoresistive element 111 and the magnetoresistive pattern 31 of the third magnetoresistive element 121 overlap in a plan view from a first direction D1 (see FIG. 7 ), which is the direction in which the first magnetoresistive element 111 and the second magnetoresistive element 112 are aligned. The magnetoresistive pattern 31 of the second magnetoresistive element 112 and the magnetoresistive pattern 31 of the fourth magnetoresistive element 122 overlap in a plan view from the first direction D1. The magnetoresistive pattern 32 of the fifth magnetoresistive element 211 and the magnetoresistive pattern 32 of the seventh magnetoresistive element 221 overlap in a plan view from a second direction D2 (see FIG. 7 ), which is a direction perpendicular to the first direction D1. The magnetoresistive pattern portion 32 of the sixth magnetoresistive element 212 and the magnetoresistive pattern portion 32 of the eighth magnetoresistive element 222 overlap in a plan view from the second direction D2. Here, "two magnetoresistive patterns 31 overlap in a plan view from the first direction D1" means that portions of the two magnetoresistive patterns 31 overlap with each other in a plan view from the first direction D1. Also, "two magnetoresistive patterns 32 overlap in a plan view from the second direction D2" means that portions of the two magnetoresistive patterns 32 overlap with each other in a plan view from the second direction D2.

[0018] In the magnetic sensor 100 according to the embodiment, the magnetoresistive pattern 31 of the first magnetoresistive element 111 and the magnetoresistive pattern 31 of the third magnetoresistive element 121 overlap in a plan view from the first direction D1. In addition, in the magnetic sensor 100, the magnetoresistive pattern 31 of the second magnetoresistive element 112 and the magnetoresistive pattern 31 of the fourth magnetoresistive element 122 overlap in a plan view from the first direction D1. In addition, in the magnetic sensor 100, the magnetoresistive pattern 32 of the fifth magnetoresistive element 211 and the magnetoresistive pattern 32 of the seventh magnetoresistive element 221 overlap in a plan view from the second direction D2. In addition, in the magnetic sensor 100, the magnetoresistive pattern 32 of the sixth magnetoresistive element 212 and the magnetoresistive pattern 32 of the eighth magnetoresistive element 222 overlap in a plan view from the second direction D2. This makes it possible to arrange the first to eighth magnetoresistance effect elements 111, 112, 121, 122, 211, 212, 221, and 222 at positions where the bias magnetic field from the bias magnet 5 is at its maximum. As a result, it becomes possible to suppress a decrease in detection accuracy compared to when two paired magnetoresistance effect elements are arranged apart from each other.

[0019] Furthermore, the first full-bridge circuit 1 and the second full-bridge circuit 2 are integrated onto a single substrate 74. Therefore, compared to a case where a first substrate on which the first full-bridge circuit 1 is mounted and a second substrate on which the second full-bridge circuit 2 is mounted are separately provided, it is possible to save the effort of adjusting the positional relationship between the first substrate and the second substrate. It is also possible to suppress a decrease in the detection accuracy of the magnetic field direction due to a deviation in the positional relationship.

[0020] Here, when the direction of the bias magnetic field or the direction in which the magnetoresistive element detects the magnetic field is along the X-axis or Y-axis, the angular difference between the two is preferably 5 degrees or less.

[0021] In the following description, in addition to the X-axis and Y-axis, a Z-axis that is orthogonal to both the X-axis and Y-axis will also be used. The X-axis, Y-axis, and Z-axis are imaginary axes set on the magnetic sensor 100 and are not tangible components.

[0022] (2) Details Next, components of the magnetic sensor 100 and the magnetic detection system 200 according to the embodiment will be described with reference to Fig. 1 and Fig. 2. Fig. 2 is a cross-sectional view of the magnetic sensor 100 according to the embodiment.

[0023] 1 and 2 , the magnetic sensor 100 according to the embodiment includes a bias magnet 5, a first protective film 71, a GMR film 72, a thermal oxide film 73, a substrate 74, and a second protective film 75. The GMR film 72 includes a first full-bridge circuit 1 and a second full-bridge circuit 2. Note that only the GMR film 72 and the bias magnet 5 are shown in FIG. 1 , and the first protective film 71, the thermal oxide film 73, the substrate 74, and the second protective film 75 are not shown.

[0024] 1, a magnetic detection system 200 according to the embodiment includes a magnetic sensor 100 and a processing circuit 201. The processing circuit 201 determines the direction of the magnetic field applied to the magnetic sensor 100 based on output signals (first output signal, second output signal, third output signal, and fourth output signal, which will be described later) of the magnetic sensor 100.

[0025] 3 is a schematic diagram showing a state in which the magnetic sensor 100 according to the embodiment is used. In this embodiment, as an example, a case will be described in which the magnetic sensor 100 and the magnetic detection system 200 are used to determine the direction of a magnetic field generated from a rotor 8 (see FIG. 3 ) of a motor, thereby determining the rotation angle of the rotor 8.

[0026] (2.1) Rotor The rotor 8 includes a plurality of permanent magnets. The plurality of permanent magnets form a plurality of magnetic poles 80. The plurality of magnetic poles 80 are aligned in the rotation direction of the rotor 8 so that north and south poles alternate. In FIG. 3, the plurality of magnetic poles 80 are aligned so that the north and south poles alternate every 45 degrees along the rotation direction of the rotor 8. Note that in FIG. 3, each magnetic pole 80 is labeled with the letter "N" representing the north pole or the letter "S" representing the south pole, but these are just letters added for the purpose of explanation and are not actually attached. The same applies to the "N" and "S" added to the bias magnet 5 in FIGS. 1 and 2.

[0027] (2.2) Bias Magnet The bias magnet 5 has a rectangular parallelepiped shape, for example, as shown in FIGS. 1 and 2 . The bias magnet 5 is a single member. For example, a permanent magnet or an electromagnet may be used as the bias magnet 5. In the present embodiment, as an example, the bias magnet 5 is a permanent magnet. The bias magnet 5 is, for example, a ferrite magnet or a neodymium magnet.

[0028] The bias magnet 5 has a plurality of (eight in this embodiment) magnetic poles 50. Four of the eight magnetic poles 50 are arranged on a first plane parallel to both the X-axis and the Y-axis. The remaining four of the eight magnetic poles 50 are arranged on a second plane parallel to the first plane.

[0029] That is, the bias magnet 5 has two sets of four magnetic poles 50, and in each set, the four magnetic poles 50 are arranged on the same plane. The magnetic poles 50 belonging to different sets are arranged at different positions in the Z-axis direction. The Z coordinates of the four magnetic poles 50 shown in FIG. 1 are greater than the Z coordinates of the remaining four magnetic poles 50.

[0030] The eight magnetic poles 50 are arranged such that adjacent magnetic poles 50 in the X-axis direction have different poles and adjacent magnetic poles 50 in the Y-axis direction have different poles. The eight magnetic poles 50 are also arranged such that adjacent magnetic poles 50 in the Z-axis direction have different poles.

[0031] The bias magnet 5 generates a bias magnetic field along the positive direction of the X axis, a bias magnetic field along the negative direction of the X axis, a bias magnetic field along the positive direction of the Y axis, and a bias magnetic field along the negative direction of the Y axis.

[0032] (2.3) Substrate The substrate 74 has a plate-like shape, for example, as shown in FIG. 2 . The substrate 74 is, for example, a silicon substrate. The substrate 74 holds the bias magnet 5, the first full-bridge circuit 1, and the second full-bridge circuit 2. Note that the substrate 74 is not limited to a silicon substrate, and may be, for example, an alumina substrate.

[0033] (2.4) GMR Film As shown in Fig. 2, the GMR film 72 is formed on the surface of the substrate 74. More specifically, the GMR film 72 is formed indirectly on the surface of the substrate 74 via a thermal oxide film 73. In this way, the substrate 74 holds the GMR film 72.

[0034] The GMR film 72 includes a plurality of layers, which are electrically connected to one another via through holes.

[0035] As shown in FIG. 1, the GMR film 72 includes a first full-bridge circuit 1 and a second full-bridge circuit 2 .

[0036] FIG. 4 is an equivalent circuit diagram of the first full-bridge circuit 1 of the magnetic sensor 100 according to the embodiment. As shown in FIG. 4 , the first full-bridge circuit 1 includes a first series circuit 11 and a second series circuit 12. The first series circuit 11 and the second series circuit 12 are connected in parallel to each other. The first series circuit 11 includes a first magnetoresistance element 111 and a second magnetoresistance element 112. The first magnetoresistance element 111 and the second magnetoresistance element 112 are connected in series to each other and detect a magnetic field along the X-axis. The second series circuit 12 includes a third magnetoresistance element 121 and a fourth magnetoresistance element 122. The third magnetoresistance element 121 and the fourth magnetoresistance element 122 are connected in series to each other and detect a magnetic field along the X-axis.

[0037] The first magnetoresistance effect element 111 and the third magnetoresistance effect element 121 are adjacent to each other in the X-axis direction. The second magnetoresistance effect element 112 and the fourth magnetoresistance effect element 122 are adjacent to each other in the X-axis direction. A bias magnetic field is applied from the bias magnet 5 to the first magnetoresistance effect element 111 and the third magnetoresistance effect element 121 in the positive direction of the X-axis. A bias magnetic field is applied from the bias magnet 5 to the second magnetoresistance effect element 112 and the fourth magnetoresistance effect element 122 in the negative direction of the X-axis.

[0038] FIG. 5 is an equivalent circuit diagram of the second full-bridge circuit 2 of the magnetic sensor 100 according to the embodiment. As shown in FIG. 5 , the second full-bridge circuit 2 includes a third series circuit 21 and a fourth series circuit 22. The third series circuit 21 and the fourth series circuit 22 are connected in parallel to each other. The third series circuit 21 includes a fifth magnetoresistance element 211 and a sixth magnetoresistance element 212. The fifth magnetoresistance element 211 and the sixth magnetoresistance element 212 are connected in series to each other and detect a magnetic field along the Y-axis. The fourth series circuit 22 includes a seventh magnetoresistance element 221 and an eighth magnetoresistance element 222. The seventh magnetoresistance element 221 and the eighth magnetoresistance element 222 are connected in series to each other and detect a magnetic field along the Y-axis.

[0039] The fifth magnetoresistance effect element 211 and the seventh magnetoresistance effect element 221 are adjacent to each other in the Y-axis direction. The sixth magnetoresistance effect element 212 and the eighth magnetoresistance effect element 222 are adjacent to each other in the Y-axis direction. A bias magnetic field is applied from the bias magnet 5 to the fifth magnetoresistance effect element 211 and the seventh magnetoresistance effect element 221 in the positive direction of the Y-axis. A bias magnetic field is applied from the bias magnet 5 to the sixth magnetoresistance effect element 212 and the eighth magnetoresistance effect element 222 in the negative direction of the Y-axis.

[0040] The magnetic sensor 100 according to the embodiment further includes a first output terminal 1T, a second output terminal 2T, a third output terminal 3T, and a fourth output terminal 4T. The first output terminal 1T outputs a first output signal from a connection point between the first magnetoresistance element 111 and the second magnetoresistance element 112. The second output terminal 2T outputs a second output signal from a connection point between the third magnetoresistance element 121 and the fourth magnetoresistance element 122. The third output terminal 3T outputs a third output signal from a connection point between the fifth magnetoresistance element 211 and the sixth magnetoresistance element 212. The fourth output terminal 4T outputs a fourth output signal from a connection point between the seventh magnetoresistance element 221 and the eighth magnetoresistance element 222. In this embodiment, the first output signal is a −cos signal, the second output signal is a +cos signal, the third output signal is a +sine signal, and the fourth output signal is a −sine signal. That is, the first output signal and the second output signal are in opposite phases, and the third output signal and the fourth output signal are in opposite phases.

[0041] Hereinafter, each of the first magnetoresistance effect element 111, the second magnetoresistance effect element 112, the third magnetoresistance effect element 121, the fourth magnetoresistance effect element 122, the fifth magnetoresistance effect element 211, the sixth magnetoresistance effect element 212, the seventh magnetoresistance effect element 221, and the eighth magnetoresistance effect element 222 may be referred to as a magnetoresistance effect element 300. In other words, the magnetic sensor 100 includes a plurality (eight) of magnetoresistance effect elements 300.

[0042] 1, the GMR film 72 further includes power supply terminals H10 and H20 and reference terminals L10 and L20. The power supply terminals H10 and H20 are high-potential terminals electrically connected to the high-potential side electrical path of the power supply. The reference terminals L10 and L20 are low-potential terminals electrically connected to the low-potential side electrical path (reference potential electrical path) of the power supply. In this embodiment, the reference terminals L10 and L20 are ground terminals electrically connected to the ground potential electrical path.

[0043] A first end of the first magnetoresistive element 111 is electrically connected to a power supply terminal H10. A second end of the first magnetoresistive element 111 is electrically connected to a first end of the second magnetoresistive element 112. A second end of the second magnetoresistive element 112 is electrically connected to a reference terminal L20. A first output terminal 1T is electrically connected to a connection point between the first magnetoresistive element 111 and the second magnetoresistive element 112.

[0044] A first end of the third magnetoresistive element 121 is electrically connected to the reference terminal L10. A second end of the third magnetoresistive element 121 is electrically connected to a first end of the fourth magnetoresistive element 122. A second end of the fourth magnetoresistive element 122 is electrically connected to the power supply terminal H20. A second output terminal 2T is electrically connected to the connection point between the third magnetoresistive element 121 and the fourth magnetoresistive element 122.

[0045] A first end of the fifth magnetoresistive element 211 is electrically connected to the reference terminal L10. A second end of the fifth magnetoresistive element 211 is electrically connected to a first end of the sixth magnetoresistive element 212. A second end of the sixth magnetoresistive element 212 is electrically connected to the power supply terminal H10. A third output terminal 3T is electrically connected to the connection point between the fifth magnetoresistive element 211 and the sixth magnetoresistive element 212.

[0046] A first end of the seventh magnetoresistive element 221 is electrically connected to the power supply terminal H20. A second end of the seventh magnetoresistive element 221 is electrically connected to a first end of the eighth magnetoresistive element 222. A second end of the eighth magnetoresistive element 222 is electrically connected to the reference terminal L20. A fourth output terminal 4T is electrically connected to the connection point between the seventh magnetoresistive element 221 and the eighth magnetoresistive element 222.

[0047] The first output terminal 1T, the second output terminal 2T, the third output terminal 3T, and the fourth output terminal 4T are electrically connected to the processing circuit 201. For simplification, FIG. 1 shows only the third output terminal 3T as being connected to the processing circuit 201.

[0048] 1 and 3 to 5, the shape of the magnetoresistive effect element 300 is illustrated as a rectangle when viewed from the Z-axis direction. However, this shape is illustrated schematically to indicate the orientation of the magnetoresistive effect element 300, and does not necessarily match the shape of the actual magnetoresistive effect element 300.

[0049] The electrical resistance value of the magnetoresistive element 300 changes depending on the magnitude of the applied magnetic field. The magnetic sensor 100 outputs the change in the electrical resistance value of the magnetoresistive element 300 as a voltage signal. The magnetoresistive element 300 is sensitive to magnetic fields in one direction (along the long side in FIG. 1 ) and is also sensitive to magnetic fields in another direction (along the short side in FIG. 1 ). The sensitivity of the magnetoresistive element 300 is greatest for magnetic fields in the other direction.

[0050] The first magnetoresistance effect element 111, the second magnetoresistance effect element 112, the third magnetoresistance effect element 121, and the fourth magnetoresistance effect element 122 are arranged to be sensitive to magnetic fields along the X-axis and the Y-axis. The first magnetoresistance effect element 111, the second magnetoresistance effect element 112, the third magnetoresistance effect element 121, and the fourth magnetoresistance effect element 122 exhibit the same change in resistance value in a magnetic field along the positive direction of the X-axis as in a magnetic field along the negative direction of the X-axis, provided that the magnitudes of the magnetic fields are the same. Furthermore, the first magnetoresistance effect element 111, the second magnetoresistance effect element 112, the third magnetoresistance effect element 121, and the fourth magnetoresistance effect element 122 exhibit the same change in resistance value in a magnetic field along the positive direction of the Y-axis as in a magnetic field along the negative direction of the Y-axis, provided that the magnitudes of the magnetic fields are the same.

[0051] The fifth magnetoresistance effect element 211, the sixth magnetoresistance effect element 212, the seventh magnetoresistance effect element 221, and the eighth magnetoresistance effect element 222 are arranged to be sensitive to magnetic fields along the X-axis and the Y-axis. The fifth magnetoresistance effect element 211, the sixth magnetoresistance effect element 212, the seventh magnetoresistance effect element 221, and the eighth magnetoresistance effect element 222 exhibit the same change in resistance value in a magnetic field along the positive direction of the X-axis as in a magnetic field along the negative direction of the X-axis, provided that the magnetic field magnitudes are the same. Furthermore, the fifth magnetoresistance effect element 211, the sixth magnetoresistance effect element 212, the seventh magnetoresistance effect element 221, and the eighth magnetoresistance effect element 222 exhibit the same change in resistance value in a magnetic field along the positive direction of the Y-axis as in a magnetic field along the negative direction of the Y-axis, provided that the magnetic field magnitudes are the same.

[0052] When viewed from the Z-axis direction, with the center of the magnetic sensor 100 as the reference, the magnetoresistive effect elements 300 are arranged as follows: The first magnetoresistive effect element 111 and the third magnetoresistive effect element 121 are arranged on the negative side of the Y-axis from the center. The second magnetoresistive effect element 112 and the fourth magnetoresistive effect element 122 are arranged on the positive side of the Y-axis from the center. The fifth magnetoresistive effect element 211 and the seventh magnetoresistive effect element 221 are arranged on the negative side of the X-axis from the center. The sixth magnetoresistive effect element 212 and the eighth magnetoresistive effect element 222 are arranged on the positive side of the X-axis from the center.

[0053] The magnetoresistive effect element 300 is, for example, a giant magnetoresistance (GMR) element. More specifically, the magnetoresistive effect element 300 is a current-in-plane (CIP) type GMR element. The magnetoresistive effect element 300 has no sensitivity in a predetermined direction (for example, the Z-axis direction) and is isotropic sensitivity in directions intersecting the predetermined direction (for example, the X-axis direction and the Y-axis direction).

[0054] The bias magnet 5 applies to each of the plurality of (eight) magnetoresistive elements 300 a magnetic field (bias magnetic field) having a strength equal to or less than half the anisotropic magnetic field of each of the plurality of magnetoresistive elements 300. This makes it possible to suppress distortion of the output waveform of each of the plurality of magnetoresistive elements 300.

[0055] (2.5) Thermal Oxide Film The thermal oxide film 73 covers the surface of the base material 74. The thermal oxide film 73 is formed on the surface of the base material 74 by performing a heat treatment on the base material 74. In this embodiment, the base material 74 is a silicon substrate, and the thermal oxide film 73 is a silicon oxide film.

[0056] (2.6) Protective Film The first protective film 71 covers the GMR film 72 as shown in FIG. 2. The first protective film 71 is made of, for example, resin or Al. ２ O ３ It is made of a metal oxide such as alumina or a metal nitride.

[0057] 2, the second protective film 75 covers the bias magnet 5 mounted on the back surface (the surface opposite to the surface on which the GMR film 72 is disposed) of the substrate 74. The second protective film 75 is formed of, for example, a resin.

[0058] (2.7) Processing Circuit The processing circuit 201 (see FIG. 1) includes, for example, a computer system having one or more processors and a memory. The functions of the processing circuit 201 are realized by the processor of the computer system executing a program recorded in the memory of the computer system. The program may be recorded in the memory, or may be provided via a telecommunications line such as the Internet, or may be recorded on a non-transitory recording medium such as a memory card and provided.

[0059] The processing circuit 201 determines the direction of the magnetic field applied to the magnetic sensor 100 based on the output signal of the magnetic sensor 100. More specifically, the processing circuit 201 determines the direction of the magnetic field applied to the magnetic sensor 100 based on the first output signal, second output signal, third output signal, and fourth output signal described above. The first output signal and second output signal are signals output from the first full-bridge circuit 1. The third output signal and fourth output signal are signals output from the second full-bridge circuit 2.

[0060] 1 and 4, the first series circuit 11 and the second series circuit 12 in the first full-bridge circuit 1 have the same sensitivity direction of the magnetoresistive element 300 and the same direction of the applied bias magnetic field, but have opposite relationships between the high potential side and the low potential side. Therefore, the second output signal has an opposite phase to the first output signal.

[0061] 1 and 5, the third series circuit 21 and the fourth series circuit 22 in the second full-bridge circuit 2 have the same sensitivity direction of the magnetoresistive element 300 and the same direction of the applied bias magnetic field, but have opposite relationships between the high potential side and the low potential side. Therefore, the fourth output signal has an opposite phase to the third output signal.

[0062] (3) Detection of Magnetic Field Direction Next, the operation of the magnetic sensor 100 according to the embodiment to detect the magnetic field direction of the rotor 8 will be described with reference to FIG.

[0063] The magnetic sensor 100 is installed near the rotor 8. The multiple magnetic poles 80 of the rotor 8 form a magnetic field. As the rotor 8 rotates, the direction of the magnetic field applied to the magnetic sensor 100 changes. The processing circuit 201 determines the direction of the magnetic field applied to the magnetic sensor 100 based on the output of the magnetic sensor 100.

[0064] Note that even when the rotor 8 does not rotate but the magnetic sensor 100 rotates relative to the rotor 8, the direction of the magnetic field applied to the magnetic sensor 100 changes, and the processing circuit 201 can determine the direction of the magnetic field. Therefore, the following description will be given with reference to Figure 3, assuming that the rotor 8 is fixed and the position of the magnetic sensor 100 changes in the order of positions L1, L2, L3, and L4. The magnetic sensor 100 rotates around the rotor 8, and the X-axis and Y-axis also rotate accordingly.

[0065] At positions L1, L2, L3, and L4, the magnetic sensor 100 is disposed radially outward of the rotor 8. In this case, the direction of the magnetic field applied to the magnetic sensor 100 is perpendicular to the direction of the rotation axis of the rotor 8, so it is necessary to adjust the orientation of the magnetic sensor 100 so that the Z axis set in the magnetic sensor 100 is aligned with the direction of the rotation axis of the rotor 8.

[0066] As the position of the magnetic sensor 100 changes in the order of positions L1, L2, L3, and L4 (actually, as the rotor 8 rotates), the first output signal, the second output signal, the third output signal, and the fourth output signal each change in a sine wave or cosine wave. Figure 6 illustrates a waveform V1 of the second output signal and a waveform V2 of the third output signal. That is, Figure 6 is an explanatory diagram showing the output signals of the magnetic sensor 100 according to the embodiment. Note that the first output signal is a signal with a phase opposite to that of the second output signal, and the fourth output signal is a signal with a phase opposite to that of the third output signal, and therefore the first output signal and the fourth output signal are not illustrated.

[0067] When the magnetic sensor 100 is at position L2, where it faces the center of the north magnetic pole 80 of the rotor 8, a magnetic field is applied to the magnetic sensor 100 along the positive direction of the X-axis. In this case, the fifth magnetoresistance element 211, the sixth magnetoresistance element 212, the seventh magnetoresistance element 221, and the eighth magnetoresistance element 222 do not detect the magnetic field. Because a bias magnetic field along the positive direction of the X-axis is applied to the first magnetoresistance element 111 and the third magnetoresistance element 121, the magnetic field of the rotor 8 and the bias magnetic field reinforce each other. On the other hand, because a bias magnetic field along the negative direction of the X-axis is applied to the second magnetoresistance element 112 and the fourth magnetoresistance element 122, the magnetic field of the rotor 8 and the bias magnetic field weaken each other. Therefore, when the magnetic sensor 100 is at position L2, the second output signal is minimum and the first output signal is maximum (see FIG. 6 ).

[0068] When the magnetic sensor 100 is at position L4, facing the center of the south pole magnetic pole 80 of the rotor 8, the direction of the magnetic field of the rotor 8 is opposite to that at position L2, so the second output signal is maximum and the first output signal is minimum (see Figure 6).

[0069] When the magnetic sensor 100 is at position L1, where it faces the boundary between the north and south magnetic poles 80 of the rotor 8, a magnetic field is applied to the magnetic sensor 100 along the negative direction of the Y axis. In this case, the first magnetoresistance element 111, the second magnetoresistance element 112, the third magnetoresistance element 121, and the fourth magnetoresistance element 122 do not detect the magnetic field. Because a bias magnetic field along the negative direction of the Y axis is applied to the sixth magnetoresistance element 212 and the eighth magnetoresistance element 222, the magnetic field of the rotor 8 and the bias magnetic field reinforce each other. On the other hand, because a bias magnetic field along the positive direction of the Y axis is applied to the fifth magnetoresistance element 211 and the seventh magnetoresistance element 221, the magnetic field of the rotor 8 and the bias magnetic field weaken each other. Therefore, when the magnetic sensor 100 is at position L1, the third output signal is maximized and the fourth output signal is minimized (see FIG. 6 ).

[0070] When the magnetic sensor 100 is at position L3, facing the boundary between the north pole magnetic pole 80 and the south pole magnetic pole 80 of the rotor 8, the direction of the magnetic field of the rotor 8 is opposite to that at position L1, so the third output signal is at a minimum and the fourth output signal is at a maximum (see Figure 6).

[0071] 3 and 6, the second output signal and the third output signal repeat the same waveforms every time the relative rotation angle between the magnetic sensor 100 and the rotor 8 changes by an amount corresponding to twice the width of the magnetic pole 80. In other words, the rotation angle corresponding to twice the width of the magnetic pole 80 corresponds to one period of the second output signal and the third output signal.

[0072] If the second output signal and the third output signal are each assumed to be a sine wave, the phase difference between the second output signal and the third output signal is a rotation angle corresponding to 1 / 2 the width of the magnetic pole 80. In other words, the phase difference is 1 / 4 period. Therefore, if the third output signal is assumed to be a sine wave, the second output signal corresponds to a cosine wave with respect to the third output signal.

[0073] The processing circuit 201 determines the rotation angle of the magnetic sensor 100 (actually, the rotor 8) based on the first output signal, the second output signal, the third output signal, and the fourth output signal. Specifically, the processing circuit 201 generates a first differential signal, which is a differential signal between the first output signal and the second output signal. The waveform of the first differential signal is a waveform with double the amplitude of the first output signal. Furthermore, the processing circuit 201 generates a second differential signal, which is a differential signal between the third output signal and the fourth output signal. The waveform of the second differential signal is a waveform with double the amplitude of the third output signal.

[0074] The processing circuit 201 determines a common phase of the first differential signal as a cosine wave and the second differential signal as a sine wave based on the first differential signal and the second differential signal. Every time the phase changes by one period, the processing circuit 201 can determine that the magnetic sensor 100 (actually, the rotor 8) has rotated by a rotation angle corresponding to one period. Because the first differential signal and the second differential signal have twice the amplitude of the first output signal and the third output signal, the direction of the magnetic field and the rotation angle of the magnetic sensor 100 (actually, the rotor 8) can be determined with higher accuracy.

[0075] The magnetic detection system 200 may include a sensor (for example, an optical sensor or a magnetic sensor) for detecting the starting point of the movement (rotation) of the measurement object (rotor 8). In this case, the sensor generates a predetermined output signal every time the measurement object makes one rotation, and the processing circuit 201 detects the starting point based on the predetermined output signal.

[0076] (4) Example of Arrangement of Magnetoresistive Effect Elements Next, an example of arrangement of the magnetoresistive effect elements 300 of the magnetic sensor 100 according to the embodiment will be described with reference to Fig. 7. Fig. 7 is a layout diagram showing an example of arrangement of the magnetoresistive effect elements 300 of the magnetic sensor 100 according to the embodiment.

[0077] 7, each of the first magnetoresistive element 111, the second magnetoresistive element 112, the third magnetoresistive element 121, and the fourth magnetoresistive element 122 has a magnetoresistive pattern portion 31 formed in a meandering shape. Also, as shown in FIG. 7, each of the fifth magnetoresistive element 211, the sixth magnetoresistive element 212, the seventh magnetoresistive element 221, and the eighth magnetoresistive element 222 has a magnetoresistive pattern portion 32 formed in a meandering shape.

[0078] The magnetoresistive pattern portion 31 of the first magnetoresistive element 111 includes a plurality of (four in the illustrated example) pattern portions 311. Each of the plurality of pattern portions 311 protrudes along the second direction D2. The plurality of pattern portions 311 are arranged along the first direction D1.

[0079] The magnetoresistive pattern portion 31 of the second magnetoresistive element 112 includes a plurality of (four in the illustrated example) pattern portions 311. Each of the plurality of pattern portions 311 protrudes along the second direction D2. The plurality of pattern portions 311 are arranged along the first direction D1.

[0080] The magnetoresistive pattern portion 31 of the third magnetoresistive element 121 includes a plurality of (four in the illustrated example) pattern portions 311. Each of the plurality of pattern portions 311 protrudes along the second direction D2. The plurality of pattern portions 311 are arranged along the first direction D1.

[0081] The magnetoresistive pattern portion 31 of the fourth magnetoresistive element 122 includes a plurality of (four in the illustrated example) pattern portions 311. Each of the plurality of pattern portions 311 protrudes along the second direction D2. The plurality of pattern portions 311 are arranged along the first direction D1.

[0082] The magnetoresistive pattern portion 32 of the fifth magnetoresistive element 211 includes a plurality of (four in the illustrated example) pattern portions 321. Each of the plurality of pattern portions 321 protrudes along the first direction D1. The plurality of pattern portions 321 are arranged along the second direction D2.

[0083] The magnetoresistive pattern portion 32 of the sixth magnetoresistive element 212 includes a plurality of (four in the illustrated example) pattern portions 321. Each of the plurality of pattern portions 321 protrudes along the first direction D1. The plurality of pattern portions 321 are arranged along the second direction D2.

[0084] The magnetoresistive pattern portion 32 of the seventh magnetoresistive element 221 includes a plurality of (four in the illustrated example) pattern portions 321. Each of the plurality of pattern portions 321 protrudes along the first direction D1. The plurality of pattern portions 321 are arranged along the second direction D2.

[0085] The magnetoresistive pattern portion 32 of the eighth magnetoresistive element 222 includes a plurality of pattern portions 321 (four in the illustrated example). Each of the plurality of pattern portions 321 protrudes along a first direction D1. The plurality of pattern portions 321 are arranged along a second direction D2. In this embodiment, the first direction D1 is the direction along the Y-axis, and the second direction D2 is the direction along the X-axis.

[0086] A first end of the magnetoresistive pattern portion 31 of the first magnetoresistive element 111 is electrically connected to the power supply terminal H10 via the wiring pattern portion 41. A second end of the magnetoresistive pattern portion 31 of the first magnetoresistive element 111 is electrically connected to the first output terminal 1T via the wiring pattern portion 49.

[0087] A first end of the magnetoresistive pattern portion 31 of the second magnetoresistive element 112 is electrically connected to the reference terminal L20 via the wiring pattern portion 47. A second end of the magnetoresistive pattern portion 31 of the second magnetoresistive element 112 is electrically connected to the first output terminal 1T via the wiring pattern portion 49.

[0088] A first end of the magnetoresistive pattern portion 31 of the third magnetoresistive element 121 is electrically connected to the reference terminal L10 via the wiring pattern portion 45. A second end of the magnetoresistive pattern portion 31 of the third magnetoresistive element 121 is electrically connected to the second output terminal 2T via the wiring pattern portion 55.

[0089] A first end of the magnetoresistive pattern portion 31 of the fourth magnetoresistive element 122 is electrically connected to the power supply terminal H20 via the wiring pattern portion 43. A second end of the magnetoresistive pattern portion 31 of the fourth magnetoresistive element 122 is electrically connected to the second output terminal 2T via the wiring pattern portion 55.

[0090] A first end of the magnetoresistive pattern portion 32 of the fifth magnetoresistive element 211 is electrically connected to the reference terminal L10 via the wiring pattern portion 46. A second end of the magnetoresistive pattern portion 31 of the fifth magnetoresistive element 211 is electrically connected to the third output terminal 3T via the wiring pattern portion 52.

[0091] A first end of the magnetoresistive pattern portion 32 of the sixth magnetoresistive element 212 is electrically connected to the power supply terminal H10 via the wiring pattern portion 42. A second end of the magnetoresistive pattern portion 32 of the sixth magnetoresistive element 212 is electrically connected to the third output terminal 3T via the wiring pattern portion 51.

[0092] A first end of the magnetoresistive pattern portion 32 of the seventh magnetoresistive element 221 is electrically connected to the power supply terminal H20 via the wiring pattern portion 44. A second end of the magnetoresistive pattern portion 32 of the seventh magnetoresistive element 221 is electrically connected to the fourth output terminal 4T via the wiring pattern portion 54.

[0093] A first end of the magnetoresistive pattern portion 32 of the eighth magnetoresistive element 222 is electrically connected to the reference terminal L20 via the wiring pattern portion 48. A second end of the magnetoresistive pattern portion 32 of the eighth magnetoresistive element 222 is electrically connected to the fourth output terminal 4T via the wiring pattern portion 53.

[0094] Here, the magnetoresistive pattern portion 31 of the first magnetoresistive element 111 and the magnetoresistive pattern portion 31 of the third magnetoresistive element 121 are symmetrical with respect to the center line L1 in the second direction D2. More specifically, each of the plurality of pattern portions 311 in the magnetoresistive pattern portion 31 of the first magnetoresistive element 111 is arranged between two adjacent pattern portions 311 of the plurality of pattern portions 311 in the magnetoresistive pattern portion 31 of the third magnetoresistive element 121. Furthermore, each of the plurality of pattern portions 311 in the magnetoresistive pattern portion 31 of the third magnetoresistive element 121 is arranged between two adjacent pattern portions 311 of the plurality of pattern portions 311 in the magnetoresistive pattern portion 31 of the first magnetoresistive element 111. As a result, the plurality of pattern portions 311 in the magnetoresistive pattern portion 31 of the first magnetoresistive element 111 and the plurality of pattern portions 311 in the magnetoresistive pattern portion 31 of the third magnetoresistive element 121 are alternately arranged along the first direction D1. That is, the magnetoresistive pattern 31 of the first magnetoresistive element 111 and the magnetoresistive pattern 31 of the third magnetoresistive element 121 overlap each other in plan view from the first direction D1.

[0095] Furthermore, the magnetoresistive pattern portion 31 of the second magnetoresistive element 112 and the magnetoresistive pattern portion 31 of the fourth magnetoresistive element 122 are symmetrical with respect to the center line L1 in the second direction D2. More specifically, each of the plurality of pattern portions 311 in the magnetoresistive pattern portion 31 of the second magnetoresistive element 112 is arranged between two adjacent pattern portions 311 of the plurality of pattern portions 311 in the magnetoresistive pattern portion 31 of the fourth magnetoresistive element 122. Furthermore, each of the plurality of pattern portions 311 in the magnetoresistive pattern portion 31 of the fourth magnetoresistive element 122 is arranged between two adjacent pattern portions 311 of the plurality of pattern portions 311 in the magnetoresistive pattern portion 31 of the second magnetoresistive element 112. As a result, the plurality of pattern portions 311 in the magnetoresistive pattern portion 31 of the second magnetoresistive element 112 and the plurality of pattern portions 311 in the magnetoresistive pattern portion 31 of the fourth magnetoresistive element 122 are alternately arranged along the first direction D1. That is, the magnetoresistive pattern 31 of the second magnetoresistive element 112 and the magnetoresistive pattern 31 of the fourth magnetoresistive element 122 overlap each other in plan view from the first direction D1.

[0096] Furthermore, the magnetoresistive pattern portion 32 of the fifth magnetoresistive element 211 and the magnetoresistive pattern portion 32 of the seventh magnetoresistive element 221 are symmetrical with respect to the center line L2 in the first direction D1. More specifically, each of the plurality of pattern portions 321 in the magnetoresistive pattern portion 32 of the fifth magnetoresistive element 211 is disposed between two adjacent pattern portions 321 of the plurality of pattern portions 321 in the magnetoresistive pattern portion 32 of the seventh magnetoresistive element 221. Furthermore, each of the plurality of pattern portions 321 in the magnetoresistive pattern portion 32 of the seventh magnetoresistive element 221 is disposed between two adjacent pattern portions 321 of the plurality of pattern portions 321 in the magnetoresistive pattern portion 32 of the fifth magnetoresistive element 211. As a result, the plurality of pattern portions 321 in the magnetoresistive pattern portion 32 of the fifth magnetoresistive element 211 and the plurality of pattern portions 321 in the magnetoresistive pattern portion 32 of the seventh magnetoresistive element 221 are alternately arranged along the second direction D2. That is, the magnetoresistive pattern 32 of the fifth magnetoresistive element 211 and the magnetoresistive pattern 32 of the seventh magnetoresistive element 221 overlap each other in plan view from the second direction D2.

[0097] Furthermore, the magnetoresistive pattern portion 32 of the sixth magnetoresistive element 212 and the magnetoresistive pattern portion 32 of the eighth magnetoresistive element 222 are symmetrical with respect to the center line L2 in the first direction D1. More specifically, each of the plurality of pattern portions 321 in the magnetoresistive pattern portion 32 of the sixth magnetoresistive element 212 is disposed between two adjacent pattern portions 321 of the plurality of pattern portions 321 in the magnetoresistive pattern portion 32 of the eighth magnetoresistive element 222. Furthermore, each of the plurality of pattern portions 321 in the magnetoresistive pattern portion 32 of the eighth magnetoresistive element 222 is disposed between two adjacent pattern portions 321 of the plurality of pattern portions 321 in the magnetoresistive pattern portion 32 of the sixth magnetoresistive element 212. As a result, the plurality of pattern portions 321 in the magnetoresistive pattern portion 32 of the sixth magnetoresistive element 212 and the plurality of pattern portions 321 in the magnetoresistive pattern portion 32 of the eighth magnetoresistive element 222 are alternately arranged along the second direction D2. That is, the magnetoresistive pattern 32 of the sixth magnetoresistive element 212 and the magnetoresistive pattern 32 of the eighth magnetoresistive element 222 overlap each other in plan view from the second direction D2.

[0098] (5) Comparison with Comparative Example Next, an example of the arrangement of the magnetoresistive effect element 300 of the magnetic sensor 100 according to the embodiment will be described in comparison with a magnetic sensor 100a according to a comparative example. Fig. 8 is a schematic diagram showing an example of the arrangement of the magnetoresistive effect element 300 of the magnetic sensor 100 according to the embodiment. Fig. 9 is a schematic diagram showing an example of the arrangement of the magnetoresistive effect element 300 of the magnetic sensor 100a according to the comparative example. Furthermore, "P1" in Figs. 8 and 9 is the position where the bias magnetic field generated by the bias magnet 5 is at its maximum (hereinafter also referred to as "maximum point P1").

[0099] 9 , in the magnetic sensor 100a according to the comparative example, the first magnetoresistance effect element 111 and the third magnetoresistance effect element 121 are disposed at positions spaced apart in the second direction D2. Furthermore, of the four maximum points P1, the maximum points P1 corresponding to the first magnetoresistance effect element 111 and the third magnetoresistance effect element 121 are located between the first magnetoresistance effect element 111 and the third magnetoresistance effect element 121 in the second direction D2.

[0100] Similarly, in the magnetic sensor 100a according to the comparative example, the second magnetoresistance effect element 112 and the fourth magnetoresistance effect element 122 are disposed at positions spaced apart in the second direction D2. Furthermore, of the four maximum points P1, the maximum points P1 corresponding to the second magnetoresistance effect element 112 and the fourth magnetoresistance effect element 122 are located between the second magnetoresistance effect element 112 and the fourth magnetoresistance effect element 122 in the second direction D2.

[0101] Similarly, in the magnetic sensor 100a according to the comparative example, the fifth magnetoresistance effect element 211 and the seventh magnetoresistance effect element 221 are disposed at positions spaced apart in the first direction D1. Furthermore, of the four maximum points P1, the maximum points P1 corresponding to the fifth magnetoresistance effect element 211 and the seventh magnetoresistance effect element 221 are located between the fifth magnetoresistance effect element 211 and the seventh magnetoresistance effect element 221 in the first direction D1.

[0102] Similarly, in the magnetic sensor 100a according to the comparative example, the sixth magnetoresistance effect element 212 and the eighth magnetoresistance effect element 222 are disposed at positions spaced apart in the first direction D1. Furthermore, of the four maximum points P1, the maximum points P1 corresponding to the sixth magnetoresistance effect element 212 and the eighth magnetoresistance effect element 222 are located between the sixth magnetoresistance effect element 212 and the eighth magnetoresistance effect element 222 in the first direction D1.

[0103] As described above, in the magnetic sensor 100a according to the comparative example, it is not possible to position each magnetoresistive element 300 at the maximum point P1 where the bias magnetic field of the bias magnet 5 is at its maximum. Therefore, for example, a magnetic field difference occurs between the first series circuit 11 including the first magnetoresistive element 111 and the second magnetoresistive element 112 and the second series circuit 12 including the third magnetoresistive element 121 and the fourth magnetoresistive element 122. Similarly, a magnetic field difference also occurs between the third series circuit 21 including the fifth magnetoresistive element 211 and the sixth magnetoresistive element 212 and the fourth series circuit 22 including the seventh magnetoresistive element 221 and the eighth magnetoresistive element 222. As a result, the magnetic field detection accuracy of the magnetic sensor 100a according to the comparative example may be reduced.

[0104] On the other hand, in the magnetic sensor 100 according to the embodiment, as described above, the first magnetoresistance effect element 111 and the third magnetoresistance effect element 121 overlap in a plan view from the first direction D1, and the two can be considered to be disposed at substantially the same position (see FIG. 8 ). Furthermore, among the four maximum points P1, the maximum points P1 corresponding to the first magnetoresistance effect element 111 and the third magnetoresistance effect element 121 overlap with both the first magnetoresistance effect element 111 and the third magnetoresistance effect element 121 in a plan view from a direction orthogonal to both the first direction D1 and the second direction D2, as shown in FIG.

[0105] Similarly, the second magnetoresistance effect element 112 and the fourth magnetoresistance effect element 122 overlap in a plan view from the first direction D1, and can be considered to be located at approximately the same position (see FIG. 8 ). Furthermore, among the four maximum points P1, the maximum points P1 corresponding to the second magnetoresistance effect element 112 and the fourth magnetoresistance effect element 122 overlap with both the second magnetoresistance effect element 112 and the fourth magnetoresistance effect element 122 in a plan view from a direction perpendicular to both the first direction D1 and the second direction D2, as shown in FIG.

[0106] Similarly, the fifth magnetoresistance effect element 211 and the seventh magnetoresistance effect element 221 overlap in a plan view from the second direction D2, and can be considered to be located at approximately the same position (see FIG. 8 ). Furthermore, among the four maximum points P1, the maximum points P1 corresponding to the fifth magnetoresistance effect element 211 and the seventh magnetoresistance effect element 221 overlap with both the fifth magnetoresistance effect element 211 and the seventh magnetoresistance effect element 221 in a plan view from a direction perpendicular to both the first direction D1 and the second direction D2, as shown in FIG.

[0107] Similarly, the sixth magnetoresistance effect element 212 and the eighth magnetoresistance effect element 222 overlap in a plan view from the second direction D2, and can be considered to be located at approximately the same position (see FIG. 8 ). Furthermore, among the four maximum points P1, the maximum points P1 corresponding to the sixth magnetoresistance effect element 212 and the eighth magnetoresistance effect element 222 overlap with both the sixth magnetoresistance effect element 212 and the eighth magnetoresistance effect element 222 in a plan view from a direction perpendicular to both the first direction D1 and the second direction D2, as shown in FIG.

[0108] As described above, in the magnetic sensor 100 according to the embodiment, each magnetoresistive element 300 can be disposed at the maximum point P1 where the bias magnetic field of the bias magnet 5 is at its maximum. Therefore, for example, the magnetic field applied to the first series circuit 11 including the first magnetoresistive element 111 and the second magnetoresistive element 112 can be made equal to the magnetic field applied to the second series circuit 12 including the third magnetoresistive element 121 and the fourth magnetoresistive element 122. Similarly, the magnetic field applied to the third series circuit 21 including the fifth magnetoresistive element 211 and the sixth magnetoresistive element 212 can be made equal to the magnetic field applied to the fourth series circuit 22 including the seventh magnetoresistive element 221 and the eighth magnetoresistive element 222. This makes it possible for the magnetic sensor 100 according to the embodiment to suppress a decrease in the accuracy of magnetic field detection by the magnetic sensor 100.

[0109] In the magnetic sensor 100 according to the embodiment, the rotor magnetic field in the X-axis direction applied by the rotor 8 is represented as H Ｒｘ The rotor magnetic field in the Y-axis direction applied by the rotor 8 is H Ｒｙ The bias magnetic field in the X-axis direction applied by the bias magnet 5 is defined as H Ｂｘ and the bias magnetic field in the Y-axis direction applied by the bias magnet 5 is H Ｂｙ In this case, the magnetic field H applied to each magnetoresistive element 300 is expressed by equation (1).

[0110]

[0111] In the following, an example will be described in which the third series circuit 21 is composed of the fifth magnetoresistance effect element 211 and the sixth magnetoresistance effect element 212. As described above, the rotor magnetic field applied to each magnetoresistance effect element 300 is a sine wave or a cosine wave. Therefore, the rotor magnetic field H in the X-axis direction applied to the fifth magnetoresistance effect element 211 is Ｒ５ｘ , the rotor magnetic field H in the Y-axis direction applied to the fifth magnetoresistance effect element 211 Ｒ５ｙ , the rotor magnetic field H in the X-axis direction applied to the sixth magnetoresistance effect element 212 Ｒ６ｘ , the rotor magnetic field H in the Y-axis direction applied to the sixth magnetoresistance effect element 212 Ｒ６ｙ are expressed by equations (2) to (5), respectively. Note that u in equations (2) to (5) ５ , u ６ is the amplitude.

[0112]

[0113]

[0114]

[0115]

[0116] Here, the bias magnetic field B applied to the fifth magnetoresistance effect element 211 ５ and the bias magnetic field B applied to the sixth magnetoresistance effect element 212 ６ If and are the same size and opposite in direction, B ５ =-B ６ The magnetic field H applied to the fifth magnetoresistance effect element 211 ５ , and the magnetic field H applied to the sixth magnetoresistance effect element 212 ６ According to equation (1), equations (6) and (7) are given.

[0117]

[0118]

[0119] Furthermore, if the x component can be ignored, the magnetic field H ５ and magnetic field H ６ are expressed as equations (8) and (9).

[0120]

[0121]

[0122] In addition, when the MR curve of each magnetoresistive element 300 is approximated by a straight line, with a slope of a1 and an intercept of b1, the resistance value R of the fifth magnetoresistive element 211 is ５ , and the resistance value R of the sixth magnetoresistive element 212 ６ are expressed as equations (10) and (11).

[0123]

[0124]

[0125] Here, the potential of the power supply terminal H10 is Vcc, and the potential of the connection point between the fifth magnetoresistance element 211 and the sixth magnetoresistance element 212, i.e., the potential of the third output signal output from the third output terminal 3T, is V1. In this case, the ratio of the potential V1 to the potential Vcc is given by equation (12).

[0126]

[0127] And the amplitude of the rotor magnetic field u ５ =u ６ In this case, the ratio of the potential V1 to the potential Vcc is given by equation (13).

[0128]

[0129] According to equation (13), the third output signal output from the third output terminal 3T can be made to approximate a cosine wave. Similarly, the fourth output signal output from the fourth output terminal 4T can be made to approximate a cosine wave. Furthermore, the first output signal output from the first output terminal 1T and the second output signal output from the second output terminal 2T can each be made to approximate a sine wave. As a result, the angle error of the magnetic sensor 100 can be reduced, and detection accuracy can be improved.

[0130] (6) Effects In the magnetic sensor 100 according to the embodiment, the magnetoresistive pattern 31 of the first magnetoresistive element 111 and the magnetoresistive pattern 31 of the third magnetoresistive element 121 overlap in a plan view from the first direction D1. More specifically, the plurality of pattern portions 311 in the magnetoresistive pattern 31 of the first magnetoresistive element 111 and the plurality of pattern portions 311 in the magnetoresistive pattern 31 of the third magnetoresistive element 121 are alternately arranged along the first direction D1. This makes it possible to make the bias magnetic field applied to the first magnetoresistive element 111 and the bias magnetic field applied to the third magnetoresistive element 121 substantially the same. Furthermore, the magnetoresistive pattern 31 of the second magnetoresistive element 112 and the magnetoresistive pattern 31 of the fourth magnetoresistive element 122 overlap in a plan view from the first direction D1. More specifically, the plurality of pattern portions 311 in the magnetoresistive pattern portion 31 of the second magnetoresistive element 112 and the plurality of pattern portions 311 in the magnetoresistive pattern portion 31 of the fourth magnetoresistive element 122 are alternately arranged along the first direction D1. This makes it possible to make the bias magnetic field applied to the second magnetoresistive element 112 and the bias magnetic field applied to the fourth magnetoresistive element 122 approximately the same. Furthermore, the magnetoresistive pattern portion 32 of the fifth magnetoresistive element 211 and the magnetoresistive pattern portion 32 of the seventh magnetoresistive element 221 overlap in a plan view from the second direction D2. More specifically, the plurality of pattern portions 321 in the magnetoresistive pattern portion 32 of the fifth magnetoresistive element 211 and the plurality of pattern portions 321 in the magnetoresistive pattern portion 32 of the seventh magnetoresistive element 221 are alternately arranged along the second direction D2. This makes it possible to make the bias magnetic field applied to the fifth magnetoresistance effect element 211 and the bias magnetic field applied to the seventh magnetoresistance effect element 221 substantially the same. Furthermore, the magnetoresistance pattern portion 32 of the sixth magnetoresistance effect element 212 and the magnetoresistance pattern portion 32 of the eighth magnetoresistance effect element 222 overlap in a plan view from the second direction D2. More specifically, the plurality of pattern portions 321 in the magnetoresistance pattern portion 32 of the sixth magnetoresistance effect element 212 and the plurality of pattern portions 321 in the magnetoresistance pattern portion 32 of the eighth magnetoresistance effect element 222 are arranged alternately along the second direction D2.This makes it possible to make the bias magnetic field applied to the sixth magnetoresistance effect element 212 and the bias magnetic field applied to the eighth magnetoresistance effect element 222 substantially the same, thereby making it possible to suppress a decrease in the detection accuracy of the magnetic sensor 100.

[0131] Furthermore, according to the magnetic sensor 100 of the embodiment, the eight magnetoresistance effect elements 300 can be arranged closer to each other, and as a result, the magnetic sensor 100 can be made smaller in size.

[0132] The magnetic sensor 100 according to the embodiment further includes a first output terminal 1T for outputting a first output signal, a second output terminal 2T for outputting a second output signal, a third output terminal 3T for outputting a third output signal, and a fourth output terminal 4T for outputting a fourth output signal, which makes it possible to output the first output signal, the second output signal, the third output signal, and the fourth output signal to an external device (e.g., the processing circuit 201).

[0133] In the magnetic sensor 100 according to the embodiment, the bias magnet 5 is a single magnet that generates a bias magnetic field along the positive direction of the X axis, a bias magnetic field along the negative direction of the X axis, a bias magnetic field along the positive direction of the Y axis, and a bias magnetic field along the negative direction of the Y axis. This makes it possible to reduce the angular error between the four bias magnetic fields, compared to a case where four bias magnets are provided corresponding to the four bias magnetic fields.

[0134] Furthermore, the magnetic detection system 200 according to the embodiment includes the magnetic sensor 100, and it is possible to suppress a decrease in the detection accuracy of the magnetic sensor 100.

[0135] (7) Modifications The above-described embodiment is merely one of various embodiments of the present disclosure. The above-described embodiment can be modified in various ways depending on the design, etc., as long as the object of the present disclosure can be achieved. Modifications of the above-described embodiment are listed below. The modifications described below can be applied in appropriate combinations.

[0136] The application of the magnetic sensor 100 is not limited to detecting the rotation angle of the detection target, but may also be used to detect linear movement of the detection target.

[0137] The power supply terminal H10 electrically connected to the first magnetoresistive element 111 and the power supply terminal H10 electrically connected to the sixth magnetoresistive element 212 may be separate terminals. Similarly, the power supply terminal H20 and the reference terminals L10 and L20 may be individually provided for each magnetoresistive element 300.

[0138] The magnetic sensor 100 may be disposed at, for example, position L41 (see FIG. 3 ). That is, the magnetic sensor 100 may be disposed at a position facing the rotor 8 in a direction parallel to the rotation axis of the rotor 8. In this case, the magnetic field applied to the magnetic sensor 100 rotates as the rotor 8 rotates, so that the magnetic field direction can be detected by the magnetic sensor 100. However, in this case, the direction of the magnetic field applied to the magnetic sensor 100 is perpendicular to the radial direction of the rotor 8, so it is necessary to adjust the orientation of the magnetic sensor 100 so that the Z axis set in the magnetic sensor 100 is aligned with the radial direction of the rotor 8.

[0139] (Aspects) The present specification discloses the following aspects.

[0140] A magnetic sensor (100) according to a first aspect includes at least one bias magnet (5), a first full-bridge circuit (1), a second full-bridge circuit (2), and a substrate (74). The at least one bias magnet (5) generates a bias magnetic field along a positive direction of the X-axis, a bias magnetic field along a negative direction of the X-axis, a bias magnetic field along a positive direction of the Y-axis, which is an axis perpendicular to the X-axis, and a bias magnetic field along a negative direction of the Y-axis. The substrate (74) holds the at least one bias magnet (5), the first full-bridge circuit (1), and the second full-bridge circuit (2). The first full-bridge circuit (1) includes a first series circuit (11) and a second series circuit (12). The first series circuit (11) includes a first magnetoresistance effect element (111) and a second magnetoresistance effect element (112) connected in series to each other and configured to detect a magnetic field along the X-axis. The second series circuit (12) includes a third magnetoresistive element (121) and a fourth magnetoresistive element (122) connected in series to each other and detecting a magnetic field along the X-axis. The first series circuit (11) and the second series circuit (12) are connected in parallel to each other. The second full-bridge circuit (2) includes a third series circuit (21) and a fourth series circuit (22). The third series circuit (21) includes a fifth magnetoresistive element (211) and a sixth magnetoresistive element (212) connected in series to each other and detecting a magnetic field along the Y-axis. The fourth series circuit (22) includes a seventh magnetoresistive element (221) and an eighth magnetoresistive element (222) connected in series to each other and detecting a magnetic field along the Y-axis. The third series circuit (21) and the fourth series circuit (22) are connected in parallel. A bias magnetic field is applied to the first magnetoresistive element (111) and the third magnetoresistive element (121) along the positive direction of the X-axis. A bias magnetic field is applied to the second magnetoresistive element (112) and the fourth magnetoresistive element (122) along the negative direction of the X-axis. A bias magnetic field is applied to the fifth magnetoresistive element (211) and the seventh magnetoresistive element (221) along the positive direction of the Y-axis. A bias magnetic field is applied to the sixth magnetoresistive element (212) and the eighth magnetoresistive element (222) along the negative direction of the Y-axis.Each of the first magnetoresistive effect element (111), the second magnetoresistive effect element (112), the third magnetoresistive effect element (121), the fourth magnetoresistive effect element (122), the fifth magnetoresistive effect element (211), the sixth magnetoresistive effect element (212), the seventh magnetoresistive effect element (221), and the eighth magnetoresistive effect element (222) has a magnetoresistive pattern portion (31, 32) formed in a meander shape. The magnetoresistive pattern portion (31) of the first magnetoresistive effect element (111) and the magnetoresistive pattern portion (31) of the third magnetoresistive effect element (121) overlap in a plan view from a first direction (D1), which is the direction in which the first magnetoresistive effect element (111) and the second magnetoresistive effect element (112) are aligned. The magnetoresistive pattern portion (31) of the second magnetoresistive effect element (112) and the magnetoresistive pattern portion (31) of the fourth magnetoresistive effect element (122) overlap when viewed from a first direction (D1). The magnetoresistive pattern portion (32) of the fifth magnetoresistive effect element (211) and the magnetoresistive pattern portion (32) of the seventh magnetoresistive effect element (221) overlap when viewed from a second direction (D2) that is perpendicular to the first direction (D1). The magnetoresistive pattern portion (32) of the sixth magnetoresistive effect element (212) and the magnetoresistive pattern portion (32) of the eighth magnetoresistive effect element (222) overlap when viewed from the second direction (D2).

[0141] According to this aspect, it is possible to suppress a decrease in the detection accuracy of the magnetic sensor (100).

[0142] In the magnetic sensor (100) relating to the second aspect, in the first aspect, the magnetoresistive pattern portion (31) of the first magnetoresistive effect element (111), the magnetoresistive pattern portion (31) of the second magnetoresistive effect element (112), the magnetoresistive pattern portion (31) of the third magnetoresistive effect element (121), and the magnetoresistive pattern portion (31) of the fourth magnetoresistive effect element (122) each have a plurality of pattern portions (311) protruding toward the second direction (D2) and aligned along the first direction (D1). Each of the magnetoresistive pattern portion (32) of the fifth magnetoresistive effect element (211), the magnetoresistive pattern portion (32) of the sixth magnetoresistive effect element (212), the magnetoresistive pattern portion (32) of the seventh magnetoresistive effect element (221), and the magnetoresistive pattern portion (32) of the eighth magnetoresistive effect element (222) has a plurality of pattern portions (321) protruding toward a first direction (D1) and arranged along a second direction (D2). The plurality of pattern portions (311) in the magnetoresistive pattern portion (31) of the first magnetoresistive effect element (111) and the plurality of pattern portions (311) in the magnetoresistive pattern portion (31) of the third magnetoresistive effect element (121) are arranged alternately along the first direction (D1). The plurality of pattern portions (311) in the magnetoresistive pattern portion (31) of the second magnetoresistive effect element (112) and the plurality of pattern portions (311) in the magnetoresistive pattern portion (31) of the fourth magnetoresistive effect element (122) are alternately arranged along the first direction (D1). The plurality of pattern portions (321) in the magnetoresistive pattern portion (32) of the fifth magnetoresistive effect element (211) and the plurality of pattern portions (321) in the magnetoresistive pattern portion (32) of the seventh magnetoresistive effect element (221) are alternately arranged along the second direction (D2). The plurality of pattern portions (321) in the magnetoresistive pattern portion (32) of the sixth magnetoresistive effect element (212) and the plurality of pattern portions (321) in the magnetoresistive pattern portion (32) of the eighth magnetoresistive effect element (222) are alternately arranged along the second direction (D2).

[0143] According to this aspect, it is possible to further suppress the deterioration of the detection accuracy of the magnetic sensor (100).

[0144] The magnetic sensor (100) according to the third aspect is the same as that according to the first or second aspect, and further includes a first output terminal (1T), a second output terminal (2T), a third output terminal (3T), and a fourth output terminal (4T). The first output terminal (1T) outputs a first output signal from a connection point between the first magnetoresistance effect element (111) and the second magnetoresistance effect element (112). The second output terminal (2T) outputs a second output signal having an opposite phase to the first output signal from a connection point between the third magnetoresistance effect element (121) and the fourth magnetoresistance effect element (122). The third output terminal (3T) outputs a third output signal from a connection point between the fifth magnetoresistance effect element (211) and the sixth magnetoresistance effect element (212). The fourth output terminal (4T) outputs a fourth output signal having a phase opposite to that of the third output signal from the connection point between the seventh magnetoresistance effect element (221) and the eighth magnetoresistance effect element (222).

[0145] According to this aspect, it is possible to output the first output signal, the second output signal, the third output signal, and the fourth output signal to the outside (for example, the processing circuit 201).

[0146] In the magnetic sensor (100) according to the fourth aspect, in any one of the first to third aspects, the at least one bias magnet (5) includes a single bias magnet (5) that generates a bias magnetic field along the positive direction of the X-axis and a bias magnetic field along the negative direction of the X-axis.

[0147] According to this aspect, it is possible to reduce the angular error between the two bias magnetic fields, compared to when a bias magnet that generates a bias magnetic field along the positive direction of the X-axis and a bias magnet that generates a bias magnetic field along the negative direction of the X-axis are provided separately.

[0148] In the magnetic sensor (100) according to the fifth aspect, in the fourth aspect, the at least one bias magnet (5) includes a single bias magnet (5) that generates a bias magnetic field along the positive direction of the X axis, a bias magnetic field along the negative direction of the X axis, a bias magnetic field along the positive direction of the Y axis, and a bias magnetic field along the negative direction of the Y axis.

[0149] According to this aspect, it is possible to reduce the angle error between the four bias magnetic fields, compared to when four bias magnets are provided corresponding to the four bias magnetic fields.

[0150] A magnetic detection system (200) according to a sixth aspect includes the magnetic sensor (100) according to any one of the first to fifth aspects and a processing circuit (201). The processing circuit (201) determines the direction of a magnetic field applied to the magnetic sensor (100) based on an output signal of the magnetic sensor (100).

[0151] According to this aspect, it is possible to suppress a decrease in the detection accuracy of the magnetic sensor (100).

[0152] The configurations according to the second to fifth aspects are not essential for the magnetic sensor (100) and can be omitted as appropriate.

[0153] The magnetic sensor and magnetic detection system according to the present disclosure can suppress a decrease in detection accuracy, and thus the magnetic sensor and magnetic detection system according to the present disclosure are industrially useful.

[0154] REFERENCE SIGNS LIST 1 First full bridge circuit 2 Second full bridge circuit 5 Bias magnet 11 First series circuit 12 Second series circuit 21 Third series circuit 22 Fourth series circuit 31, 32 Magnetoresistive pattern portion 74 Substrate 100 Magnetic sensor 111 First magnetoresistive effect element 112 Second magnetoresistive effect element 121 Third magnetoresistive effect element 122 Fourth magnetoresistive effect element 200 Magnetic detection system 201 Processing circuit 211 Fifth magnetoresistive effect element 212 Sixth magnetoresistive effect element 221 Seventh magnetoresistive effect element 222 Eighth magnetoresistive effect element 311, 321 Pattern portion D1 First direction D2 Second direction 1T First output terminal 2T Second output terminal 3T Third output terminal 4T Fourth output terminal

Claims

1. At least one bias magnet that generates a bias magnetic field along the positive direction of the X-axis, a bias magnetic field along the negative direction of the X-axis, a bias magnetic field along the positive direction of the Y-axis which is an axis orthogonal to the X-axis, and a bias magnetic field along the negative direction of the Y-axis; a first full-bridge circuit; a second full-bridge circuit; and a base material that holds the at least one bias magnet, the first full-bridge circuit, and the second full-bridge circuit, The first full-bridge circuit includes: A first series circuit including a first magnetoresistive element and a second magnetoresistive element that are connected in series with each other and detect a magnetic field along the X-axis; A second series circuit including a third magnetoresistive element and a fourth magnetoresistive element that are connected in series with each other and detect a magnetic field along the X-axis, The first series circuit and the second series circuit are connected in parallel with each other, The second full-bridge circuit includes: A third series circuit including a fifth magnetoresistive element and a sixth magnetoresistive element that are connected in series with each other and detect a magnetic field along the Y-axis; A fourth series circuit including a seventh magnetoresistive element and an eighth magnetoresistive element that are connected in series with each other and detect a magnetic field along the Y-axis, The third series circuit and the fourth series circuit are connected in parallel with each other, The bias magnetic field along the positive direction of the X-axis is applied to the first magnetoresistive element and the third magnetoresistive element, The bias magnetic field along the negative direction of the X-axis is applied to the second magnetoresistive element and the fourth magnetoresistive element, The bias magnetic field along the positive direction of the Y-axis is applied to the fifth magnetoresistive element and the seventh magnetoresistive element, The bias magnetic field along the negative direction of the Y-axis is applied to the sixth magnetoresistive element and the eighth magnetoresistive element, Each of the first magnetoresistive element, the second magnetoresistive element, the third magnetoresistive element, the fourth magnetoresistive element, the fifth magnetoresistive element, the sixth magnetoresistive element, the seventh magnetoresistive element, and the eighth magnetoresistive element has a magnetoresistive pattern portion formed in a meander shape.The magnetoresistive pattern portion of the first magnetoresistive element and the magnetoresistive pattern portion of the third magnetoresistive element overlap in a plan view from a first direction which is a direction in which the first magnetoresistive element and the second magnetoresistive element are arranged; the magnetoresistive pattern portion of the second magnetoresistive element and the magnetoresistive pattern portion of the fourth magnetoresistive element overlap in a plan view from the first direction; the magnetoresistive pattern portion of the fifth magnetoresistive element and the magnetoresistive pattern portion of the seventh magnetoresistive element overlap in a plan view from a second direction which is a direction orthogonal to the first direction; the magnetoresistive pattern portion of the sixth magnetoresistive element and the magnetoresistive pattern portion of the eighth magnetoresistive element overlap in a plan view from the second direction, a magnetic sensor.

2. Each of the magnetoresistive pattern portions of the first magnetoresistive effect element, the magnetoresistive pattern portions of the second magnetoresistive effect element, the magnetoresistive pattern portions of the third magnetoresistive effect element, and the magnetoresistive pattern portions of the fourth magnetoresistive effect element has a plurality of pattern portions that protrude in the second direction and are arranged along the first direction. Each of the magnetoresistive pattern portions of the fifth magnetoresistive effect element, the magnetoresistive pattern portions of the sixth magnetoresistive effect element, the magnetoresistive pattern portions of the seventh magnetoresistive effect element, and the magnetoresistive pattern portions of the eighth magnetoresistive effect element has a plurality of pattern portions that protrude in the first direction and are arranged along the second direction. The plurality of pattern portions in the magnetoresistive pattern portion of the first magnetoresistive effect element and the plurality of pattern portions in the magnetoresistive pattern portion of the third magnetoresistive effect element are alternately arranged along the first direction. The plurality of pattern portions in the magnetoresistive pattern portion of the second magnetoresistive effect element and the plurality of pattern portions in the magnetoresistive pattern portion of the fourth magnetoresistive effect element are alternately arranged along the first direction. The plurality of pattern portions in the magnetoresistive pattern portion of the fifth magnetoresistive effect element and the plurality of pattern portions in the magnetoresistive pattern portion of the seventh magnetoresistive effect element are alternately arranged along the second direction. The plurality of pattern portions in the magnetoresistive pattern portion of the sixth magnetoresistive effect element and the plurality of pattern portions in the magnetoresistive pattern portion of the eighth magnetoresistive effect element are alternately arranged along the second direction. The magnetic sensor according to claim 1.

3. A first output terminal that outputs a first output signal from a connection point between the first magnetoresistive effect element and the second magnetoresistive effect element, a second output terminal that outputs a second output signal having a reverse phase to the first output signal from a connection point between the third magnetoresistive effect element and the fourth magnetoresistive effect element, a third output terminal that outputs a third output signal from a connection point between the fifth magnetoresistive effect element and the sixth magnetoresistive effect element, and a fourth output terminal that outputs a fourth output signal having a reverse phase to the third output signal from a connection point between the seventh magnetoresistive effect element and the eighth magnetoresistive effect element. The magnetic sensor according to claim 1, further comprising:

4. The magnetic sensor according to claim 1, wherein the at least one bias magnet includes a single bias magnet that generates the bias magnetic field along the positive direction of the X axis and the bias magnetic field along the negative direction of the X axis.

5. The magnetic sensor according to claim 1, wherein the at least one bias magnet includes a single bias magnet that generates the bias magnetic field along the positive direction of the X axis, the bias magnetic field along the negative direction of the X axis, the bias magnetic field along the positive direction of the Y axis, and the bias magnetic field along the negative direction of the Y axis.

6. A magnetic detection system comprising: the magnetic sensor according to any one of claims 1 to 5; and a processing circuit configured to determine a direction of a magnetic field applied to the magnetic sensor based on an output signal of the magnetic sensor.

Images