JP2020003280A - Magnetic sensor - Google Patents

Abstract

To enhance detection sensitivity of a magnetic sensor provided with a permanent magnet for applying a bias magnetic field to a sensor chip and a magnetism attraction member for attracting magnetic fluxes to the sensor chip.SOLUTION: A magnetic sensor comprises a sensor chip 20 arranged so as to be sandwiched by permanent magnets 41, 42 from a direction z and having a magneto-sensitive element, and a magnetism attraction member 30 for attracting magnetic fluxes to the magneto-sensitive element. A center position of the magnetism attraction member 30 in the direction z is aligned to a center Z0 of the permanent magnets 41, 42 in the direction z and a position Zr of the magneto-sensitive element in the direction z is offset relative to the center Z0. According to the present invention, as the magneto-sensitive element is arranged by being offset relative to the center Zr, a magnetic flux φ released from the vicinity of a corner of the magnetism attraction member 30 is efficiently applied to the magneto-sensitive element. Thus, it is possible to obtain high detection sensitivity than in the case where the magneto-sensitive element is aligned to the center Z0.SELECTED DRAWING: Figure 2

Description

  The present invention relates to a magnetic sensor, and more particularly, to a magnetic sensor including a permanent magnet that applies a bias magnetic field to a sensor chip.

  Some magnetic sensors include a permanent magnet that applies a bias magnetic field to a sensor chip. For example, Patent Document 1 discloses a magnetic sensor including two permanent magnets in which the positions of an N pole and an S pole are inverted with each other, and a sensor chip arranged so as to be sandwiched between these two permanent magnets. I have. In the magnetic sensor described in Patent Literature 1, a sensor chip is disposed at a center position between two permanent magnets.

Japanese Patent No. 6209674

  However, a magnetic sensor may use a magnetic flux collecting member for collecting magnetic flux on a sensor chip. In this case, since the magnetic flux changes depending on the magnetic flux collecting member, if the sensor chip is aligned with the center position between the two permanent magnets, sufficient detection sensitivity may not be obtained.

  Accordingly, an object of the present invention is to further increase the detection sensitivity in a magnetic sensor including a permanent magnet for applying a bias magnetic field to a sensor chip and a magnetic flux collecting member for collecting magnetic flux in the sensor chip.

  A magnetic sensor according to the present invention includes first and second permanent magnets arranged in a first direction, and a magnetic sensor arranged between the first and second permanent magnets from the first direction. A sensor chip, and a magnetic flux collecting member arranged to be sandwiched between the first and second permanent magnets from the first direction and collecting magnetic flux in the magneto-sensitive element, and the center position of the magnetic flux collecting member in the first direction is , Centered in a first direction between the first permanent magnet and the second permanent magnet, and the position of the magneto-sensitive element in the first direction is between the first permanent magnet and the second permanent magnet. Is offset with respect to the center in the first direction.

  According to the present invention, since the magnetic flux collecting member is aligned with the center between the first permanent magnet and the second permanent magnet, the magnetic flux flowing through the magnetic flux collecting member is largely changed according to the change in the bias magnetic field. be able to. Moreover, since the magneto-sensitive element is arranged offset with respect to the center of the first permanent magnet and the second permanent magnet, the magnetic flux emitted from near the corner of the magnetic flux collecting member is applied to the magneto-sensitive element. It is applied efficiently. Thereby, higher detection sensitivity can be obtained as compared with the case where the magneto-sensitive element is aligned with the centers of the first permanent magnet and the second permanent magnet.

  In the present invention, the sensor chip has an element forming surface on which the magneto-sensitive element is formed, and the element forming surface may be orthogonal to the first direction. According to this, a magnetic flux parallel to the element formation surface can be detected.

  In the present invention, the position of the element formation surface in the first direction may overlap the magnetic flux collecting member. According to this, since the magnetic flux is more efficiently applied to the element formation surface, it is possible to obtain higher detection sensitivity.

  The magnetic sensor according to the present invention has a first magnetic shield disposed between the sensor chip and the magnetic flux collecting member and the first permanent magnet, and a first magnetic shield disposed between the sensor chip and the magnetic flux collecting member and the second permanent magnet. A second magnetic shield may be further provided. According to this, since the magnetic flux from the first and second permanent magnets is not directly applied to the sensor chip, the magneto-sensitive element is less likely to be saturated.

  The magnetic sensor according to the present invention further includes a circuit board on which a sensor chip and a magnetic flux collecting member are mounted on a main surface, an element forming surface of the sensor chip is parallel to the main surface of the circuit board, and the magnetic flux collecting member includes a sensor. It may be mounted on the main surface of the circuit board without contacting the element forming surface of the chip. According to this, since the magnetic flux collecting member has a structure that does not contact the element forming surface of the sensor chip, even if an external force is applied to the magnetic flux collecting member, this can be transmitted to the element forming surface of the sensor chip. Absent.

  In the present invention, the sensor chip further has first and second side surfaces that are perpendicular to the main surface of the circuit board and are parallel to each other, and the magnetic flux collecting member includes the first and second side surfaces of the sensor chip. , And a third portion connecting the first portion and the second portion. According to this, the magnetic flux collected by the third part can be bent by the first and second parts.

  In the present invention, the magnetic flux collecting member includes a magnetic portion made of a magnetic material and a nonmagnetic portion made of a nonmagnetic material, and the nonmagnetic portion is located between the main surface of the circuit board and the magnetic portion. No problem. According to this, a thin magnetic portion such as a metal magnetic material can be used.

  As described above, according to the present invention, it is possible to further increase the detection sensitivity in the magnetic sensor including the permanent magnet for applying the bias magnetic field to the sensor chip and the magnetic flux collecting member for collecting the magnetic flux in the sensor chip. .

FIG. 1 is a schematic perspective view for explaining the structure of the magnetic sensor 1 according to the first embodiment of the present invention. FIG. 2 is a sectional view of the magnetic sensor 1. FIG. 3 is a schematic perspective view for explaining the structure of the sensor chip 20 and the magnetic flux collecting member 30 mounted on the circuit board 10. FIG. 4 is a schematic side view for explaining the structure of the sensor chip 20 and the magnetic flux collecting member 30 mounted on the circuit board 10. FIG. 5 is a schematic xy plan view for explaining the flow of the magnetic flux φ. FIG. 6 is a circuit diagram showing a connection relationship between the magneto-sensitive elements R1 and R2. FIG. 7 is a schematic yz plan view for explaining the flow of the magnetic flux φ. FIG. 8 is a graph showing the relationship between the position Zr of the magnetosensitive elements R1 and R2 in the z direction and the detection sensitivity. FIG. 9 is an xz side view for explaining the configuration of the main part of the magnetic sensor 1a according to the first modification. FIG. 10 is an xz side view for explaining the configuration of the main part of the magnetic sensor 1b according to the second modification. FIG. 11 is a schematic plan view showing the structure of the element formation surface 25 of the sensor chip 20A according to the first modification. FIG. 12 is a schematic plan view showing the structure of the element formation surface 25 of the sensor chip 20B according to the second modification. FIG. 13 is a plan view showing the shape of the magnetic flux collecting member 30A according to the first modification. FIG. 14 is a plan view showing the shape of a magnetic flux collecting member 30B according to a second modification. FIG. 15 is a schematic perspective view for explaining the structure of the main part of the magnetic sensor 2 according to the second embodiment of the present invention. FIG. 16 is a schematic xy side view for explaining the structure of the main part of the magnetic sensor 2. FIG. 17 is a schematic xy side view for explaining the structure of the main part of the magnetic sensor 2a according to the modification. FIG. 18 is a schematic sectional view illustrating the structure of the magnetic sensor 3 according to the third embodiment of the present invention.

  Hereinafter, preferred embodiments of the present invention will be described in detail with reference to the accompanying drawings.

<First embodiment>
FIG. 1 is a schematic perspective view for explaining the structure of the magnetic sensor 1 according to the first embodiment of the present invention. FIG. 2 is a sectional view of the magnetic sensor 1.

  As shown in FIGS. 1 and 2, the magnetic sensor 1 according to the first embodiment includes a housing 50 made of a nonmagnetic material such as a resin, a circuit board 10 built in the housing 50, a sensor chip 20, A magnetic member 30 and permanent magnets 41 and 42 are provided. Each of the permanent magnets 41 and 42 has the y direction as the magnetic pole direction, and the positions of the N pole and the S pole are reversed. Thereby, a magnetic flux φ shown in FIG. 2 is generated between the permanent magnet 41 and the permanent magnet 42, and this is used as a bias magnetic field. The circuit board 10, the sensor chip 20, and the magnetic flux collecting member 30 are arranged so as to be sandwiched between the permanent magnet 41 and the permanent magnet 42 in the z direction. The sensor chip 20 and the magnetic flux collecting member 30 are mounted on the main surface 11 of the circuit board 10.

  Here, when the position of the end surface of the permanent magnet 41 on the sensor chip 20 side in the z direction is Z1 and the position of the end surface of the permanent magnet 42 on the sensor chip 20 side in the z direction is Z2, the z direction of the magnetic flux collecting member 30 is Is aligned with the center Z0 of the position Z1 and the position Z2 in the z direction. The distance between the center Z0 and the positions Z1 and Z2 in the z direction is d.

  3 and 4 are a schematic perspective view and a schematic side view, respectively, for explaining the structures of the sensor chip 20 and the magnetic flux collecting member 30 mounted on the circuit board 10.

  As shown in FIG. 3, the main surface 11 of the circuit board 10 forms an xy plane, and the sensor chip 20 and the magnetic flux collecting member 30 are mounted on the main surface 11 of the circuit board 10. The sensor chip 20 has side surfaces 21 and 22 forming a yz surface, side surfaces 23 and 24 forming an xz surface, an element forming surface 25 and a back surface 26 forming an xy surface, and the back surface 26 is a circuit. It is mounted on the circuit board 10 so as to face the main surface 11 of the board 10. The fixing of the sensor chip 20 can be performed by applying an adhesive between the circuit board 10 and the back surface 26 of the sensor chip 20. Further, the electrical connection between the sensor chip 20 and the circuit board 10 can be performed using a bonding wire (not shown) or the like.

  On the element forming surface 25, two magneto-sensitive elements R1 and R2 are formed. As the magneto-sensitive elements R1 and R2, a magneto-resistive element whose resistance value changes according to the direction and strength of the magnetic field can be used. Among them, the magneto-sensitive element R1 is arranged near the side face 21 and the magneto-sensitive element R2 is arranged near the side face 22.

  The magnetic flux collecting member 30 is a block made of a single magnetic material such as ferrite, and includes first and second portions 31 and 32 that cover the side surfaces 21 and 22 of the sensor chip 20, respectively, and a first portion 31 and a second portion. It has a third portion 33 connecting the two portions 32. In the example shown in FIG. 3, the first and second portions 31 and 32 of the magnetic flux collecting member 30 respectively cover a part of the side surfaces 21 and 22 of the sensor chip 20. The shape may be completely covered.

  The magnetic flux collecting member 30 has a function of collecting the magnetic flux in the y direction by the third portion 33 and distributing the magnetic flux to the first and second portions 31 and 32. As shown in FIG. 4 which is a schematic side view seen from the y direction, the position of one end surface (lower surface) of the magnetic flux collecting member 30 in the z direction is Z3, and the other end surface (upper surface) of the magnetic flux collecting member 30 in the z direction. If the position of ()) is Z4, the center position of the magnetic flux collecting member 30 in the z direction is aligned with the center Z0 described above. The distance between the center Z0 and the positions Z3 and Z4 in the z direction is h.

  On the other hand, the position Zr of the magneto-sensitive elements R1 and R2 in the z direction is offset from the center Z0 described above. In the present embodiment, the magnetosensitive elements R1, R2 and the magnetic flux collecting member 30 have an overlap when viewed from the y direction, and the position Zr of the magnetosensitive elements R1, R2 exists between the center Z0 and the position Z4. are doing.

  FIG. 5 is a schematic xy plan view for explaining the flow of the magnetic flux φ.

  As shown in FIG. 5, the magnetic flux φ in the y direction is sucked into the magnetic flux collecting member 30 from the third portion 33, and is bent in the x direction by the first and second portions 31, 32. Since the magneto-sensitive elements R1 and R2 are arranged near the first and second portions 31 and 32 of the magnetic flux collecting member 30 in the x direction, the magnetic flux φ passing through the magnetic flux collecting member 30 is: In the vicinity of the magneto-sensitive elements R1 and R2, not only the y-direction component but also the x-direction component is provided.

  Here, the fixed magnetization directions of the magneto-sensitive elements R1 and R2 are aligned in the direction (x direction) indicated by the arrow P shown in FIG. On the other hand, since the x-direction component of the magnetic flux φ sucked into the magnetic flux collecting member 30 is opposite to each other in the magnetic sensing element R1 and the magnetic sensing element R2, the resistance of the magnetic sensing elements R1 and R2 depends on the density of the magnetic flux φ. Values will differ. Such a difference between the resistance values is taken out as an output signal Vout from the series circuit shown in FIG. 6, so that the magnetic flux φ can be detected.

  FIG. 7 is a schematic yz plan view for explaining the flow of the magnetic flux φ.

  As shown in FIG. 7, the magnetic flux φ in the y direction sucked into the magnetic flux collecting member 30 tends to escape from the vicinity of the corner of the magnetic flux collecting member 30 to the outside. That is, inside the magnetic flux collecting member 30, the magnetic flux φ is bent to the positions Z3 and Z4, which are ends in the z direction. As a result, the density of the magnetic flux φ released from the magnetic flux collecting member 30 becomes higher than the center Z0 at the position Z3. , Z4 are higher. In consideration of this point, in the present embodiment, the position Zr of the magneto-sensitive elements R1 and R2 in the z direction is offset from the center Z0 to the position Z4. As a result, more magnetic flux φ is given to the magneto-sensitive elements R1 and R2 than when the position Zr of the magneto-sensitive elements R1 and R2 in the z direction in the z direction is aligned with the center Z0. Becomes possible.

  FIG. 8 is a graph showing the relationship between the position Zr of the magnetosensitive elements R1 and R2 in the z direction and the detection sensitivity.

  As shown in FIG. 8, the magnetic sensor 1 according to the present embodiment has a configuration in which the position Zr of the magnetosensitive elements R1 and R2 in the z direction overlaps with the magnetic flux collecting member 30, that is, the position Zr is between the position Z3 and the position Z4. In some cases, high detection sensitivity is obtained. However, the peak of the detection sensitivity is not at the center Z0, but exists near the position Z3 and near the position Z4. This is because, as described above, the magnetic flux φ sucked into the magnetic flux collecting member 30 tends to escape from the corner to the outside. Therefore, the highest detection sensitivity can be obtained by laying out the magneto-sensitive elements R1 and R2 at the z-direction position where the detection sensitivity reaches a peak.

  Moreover, in the present embodiment, the side surfaces 21 to 23 of the sensor chip 20 are covered by the magnetic flux collecting member 30, while the element forming surface 25 of the sensor chip 20 is not covered by the magnetic flux collecting member 30. Therefore, even if an external force is applied to the magnetic flux collecting member 30, the external force is not directly transmitted to the element forming surface 25 of the sensor chip 20. Therefore, stress is less likely to be applied to the element formation surface 25 of the sensor chip 20, and as a result, the reliability of the magnetic sensor 1 can be improved. However, the element formation surface 25 of the sensor chip 20 may be partially covered by the magnetic flux collecting member 30. Even in this case, an external force is applied to the magnetic flux collecting member 30 unless the element forming surface 25 of the sensor chip 20 is in direct contact with the magnetic flux collecting member 30 or indirectly via an adhesive or the like. However, this external force is not directly transmitted to the element forming surface 25 of the sensor chip 20.

  In the above embodiment, the position Zr of the magneto-sensitive elements R1 and R2 in the z direction is offset from the center Z0 to the position Z4, but conversely, the position Zr may be offset from the center Z0 to the position Z3. .

  FIG. 9 is an xz side view for explaining the configuration of the main part of the magnetic sensor 1a according to the first modification. In the example shown in FIG. 9, the thickness of the sensor chip 20 is set to be less than half the thickness of the magnetic flux collecting member 30 in the z direction, so that the position Zr of the magnetosensitive elements R1 and R2 in the z direction is shifted from the center Z0 to the position Z3. Offset. Even with such a configuration, it is possible to obtain the same effect as the above embodiment.

  FIG. 10 is an xz side view for explaining the configuration of the main part of the magnetic sensor 1b according to the second modification. In the example shown in FIG. 10, the sensor chip 20 is mounted on the circuit board 10 upside down. That is, the sensor chip 20 is mounted on the circuit board 10 so that the element forming surface 25 and the main surface 11 face each other. Thus, the position Zr of the magneto-sensitive elements R1 and R2 in the z direction can be offset from the center Z0 to the position Z3, so that the same effect as in the above embodiment can be obtained. Moreover, in the example shown in FIG. 10, since the element forming surface 25 of the sensor chip 20 is covered with the main surface 11 of the circuit board 10, the element forming surface 25 of the sensor chip 20 is physically protected. Benefits are also obtained.

  FIG. 11 is a schematic plan view showing the structure of the element formation surface 25 of the sensor chip 20A according to the first modification. The sensor chip 20A according to the first modified example is different from the above-described sensor chip 20 in that the magnetic layers 51 and 52 are formed on the element formation surface 25. The magnetic layers 51 and 52 may be films made of a composite magnetic material in which a magnetic filler is dispersed in a resin material, or may be thin films or foils made of a soft magnetic material such as nickel or permalloy. It may be a thin film or a bulk sheet made of ferrite or the like. Further, the magnetic layers 51 and 52 may be located above the magneto-sensitive elements R1 and R2, may be located below, or may be located in the same layer.

  In the sensor chip 20A according to the first modified example, the magnetic layer 51 is disposed adjacent to the side surface 21 adjacent to the magneto-sensitive element R1, and the magnetic layer 52 is disposed adjacent to the magnetic sensing element R2. Is arranged in the vicinity of. As a result, the magnetic resistance in the vicinity of the magneto-sensitive elements R1 and R2 decreases, so that more magnetic flux can be applied to the magneto-sensitive elements R1 and R2.

  FIG. 12 is a schematic plan view showing the structure of the element formation surface 25 of the sensor chip 20B according to the second modification. The sensor chip 20B according to the second modification is different from the sensor chip 20A according to the first modification in that a magnetic layer 53 is further added on the element formation surface 25. The magnetic layer 53 may be made of the same magnetic material as the magnetic layers 51 and 52. The magnetic layer 53 may be located above the magneto-sensitive elements R1 and R2, may be located below, or may be located in the same layer.

  In the sensor chip 20B according to the second modification, the magnetic layer 53 is disposed so as to be sandwiched between the magneto-sensitive element R1 and the magneto-sensitive element R2 in the x direction. The magnetic flux easily flows between the magnetic layers 53. Thereby, the x-direction component of the magnetic flux applied to the magneto-sensitive elements R1 and R2 is increased, so that higher detection sensitivity can be obtained.

  FIG. 13 is a plan view showing the shape of the magnetic flux collecting member 30A according to the first modification. The magnetic flux collecting member 30A according to the first modification has the above-described configuration in which both sides are tapered so that the width of the first and second portions 31 and 32 in the x direction becomes thinner toward the distal end. This is different from the magnetic flux collecting member 30 described above. According to this, the magnetic flux φ taken in from the third portion 33 is collected by the first and second tapered portions 31 and 32 in the magneto-sensitive elements R1 and R2. Can be applied with the magnetic flux φ of the x direction component.

  FIG. 14 is a plan view showing the shape of a magnetic flux collecting member 30B according to a second modification. The magnetic flux collecting member 30B according to the second modification is substantially C-shaped in plan view, and differs from the magnetic flux collecting member 30 described above in that the third portion 33 is largely separated from the side surface 23 of the sensor chip 20. are doing. Thus, in the present invention, it is not essential that the side surfaces 21 to 23 of the sensor chip 20 and the first to third portions 31 to 33 of the magnetic flux collecting member 30 are close to each other. And the third portion 33 of the magnetic flux collecting member 30B may be separated from each other. Also in such a structure, the magnetic flux φ taken in from the third portion 33 is applied to the magneto-sensitive elements R1 and R2 via the first and second portions 31 and 32, and the magneto-sensitive elements R1 and R2 Can be increased in the x-direction component of the magnetic flux φ applied to the.

<Second embodiment>
FIG. 15 is a schematic perspective view for explaining the structure of the main part of the magnetic sensor 2 according to the second embodiment of the present invention.

  As shown in FIG. 15, the magnetic sensor 2 according to the second embodiment differs from the magnetic sensor 2 according to the first embodiment in that the magnetic flux collecting member 30 includes a magnetic part 30M made of a magnetic material and a nonmagnetic part 30N made of a nonmagnetic material. Is different from the magnetic sensor 1 of FIG. Since other basic configurations are the same as those of the magnetic sensor 1 according to the first embodiment, the same components are denoted by the same reference numerals, and redundant description will be omitted.

  The magnetic part 30 </ b> M of the magnetic flux collecting member 30 is a part that collects the magnetic flux in the y direction and applies the magnetic flux to the magnetic sensing elements R <b> 1 and R <b> 2 of the sensor chip 20. On the other hand, the nonmagnetic portion 30N of the magnetic flux collecting member 30 is located between the main surface 11 of the circuit board 10 and the magnetic portion 30M, and the height of the magnetic portion 30M in the z direction is the height of the magnetosensitive elements R1 and R2. It is the part that plays the role of raising the height. That is, as shown in FIG. 16 which is a schematic side view as viewed from the y direction, the lower surface of the magnetic portion 30M with respect to the main surface 11 of the circuit board 10 is formed by the non-magnetic portion 30N present below the magnetic portion 30M. The height of the magnetic part 30M is maintained such that the magneto-sensitive elements R1 and R2 are located between the position Z3 and the position Z4 on the upper surface.

  In the present embodiment, the position Zr of the magneto-sensitive elements R1 and R2 in the z direction is offset from the center Z0 to the position Z3. Thereby, the same effect as that of the first embodiment can be obtained. Alternatively, like the magnetic sensor 2a according to the first modification of the present embodiment shown in FIG. 17, the position Zr of the magneto-sensitive elements R1 and R2 in the z direction may be offset from the center Z0 to the position Z4. .

  In the present embodiment, the magnetic portion 30M can be made of a metal magnetic material such as permalloy, and the nonmagnetic portion 30N can be made of a nonmagnetic resin. In this case, the magnetic flux collecting member 30 shown in FIGS. 15 to 17 can be manufactured by processing a metal magnetic plate made of a permalloy or the like into a predetermined shape by a punching method, and attaching this to a resin. When the magnetic portion 30M is manufactured by punching a metal magnetic plate such as permalloy, the thickness of the magnetic portion 30M is constant, while the thickness of the sensor chip 20 may differ depending on the product. Even in such a case, it is possible to maintain the height of the magnetic portion 30M at a desired height by changing the thickness of the nonmagnetic portion 30N.

<Third embodiment>
FIG. 18 is a schematic sectional view illustrating the structure of the magnetic sensor 3 according to the third embodiment of the present invention.

  As shown in FIG. 18, the magnetic sensor 3 according to the third embodiment is different from the magnetic sensor 1 according to the first embodiment in that magnetic shields 61 and 62 are added. Since other basic configurations are the same as those of the magnetic sensor 1 according to the first embodiment, the same components are denoted by the same reference numerals, and redundant description will be omitted.

  The magnetic shield 61 is disposed between the permanent magnet 41 and the sensor chip 20 and the magnetic flux collecting member 30, and the magnetic shield 62 is disposed between the permanent magnet 42 and the sensor chip 20 and the magnetic flux collecting member 30. The magnetic shields 61 and 62 serve to prevent the magnetic flux from the permanent magnets 41 and 42 from being directly applied to the sensor chip 20. Therefore, by providing the magnetic shields 61 and 62, it is possible to obtain an effect that the magneto-sensitive elements R1 and R2 are hardly saturated.

  As described above, the preferred embodiments of the present invention have been described. However, the present invention is not limited to the above embodiments, and various modifications can be made without departing from the gist of the present invention. It goes without saying that they are included in the range.

1, 1a, 1b, 2, 2a, 3 Magnetic sensor 10 Circuit board 11 Main surface 20, 20A, 20B Sensor chip 21 to 24 Side surface 25 Element formation surface 26 Back surface 30, 30A, 30B Magnetic collecting member 30M Magnetic portion 30N Nonmagnetic Part 31 First part 32 Second part 33 Third part 41, 42 Permanent magnet 50 Cases 51 to 53 Magnetic layers 61, 62 Magnetic shields R1, R2 Magnetic sensing element φ Magnetic flux

Claims (7)

First and second permanent magnets arranged in a first direction;
A sensor chip disposed between the first and second permanent magnets from the first direction and having a magneto-sensitive element;
A magnetic flux collecting member arranged to be sandwiched between the first and second permanent magnets from the first direction, and to collect magnetic flux in the magneto-sensitive element;
A center position of the magnetic flux collecting member in the first direction is aligned with a center in the first direction between the first permanent magnet and the second permanent magnet,
The position of the magneto-sensitive element in the first direction is offset with respect to a center in the first direction between the first permanent magnet and the second permanent magnet. Sensors. The sensor chip has an element forming surface on which the magneto-sensitive element is formed,
The magnetic sensor according to claim 1, wherein the element forming surface is orthogonal to the first direction.   The magnetic sensor according to claim 2, wherein a position of the element forming surface in the first direction has an overlap with the magnetic flux collecting member. A first magnetic shield disposed between the sensor chip and the magnetic flux collecting member and the first permanent magnet;
4. The magnetic sensor according to claim 2, further comprising a second magnetic shield disposed between the sensor chip and the magnetic flux collecting member and the second permanent magnet. 5. Further comprising a circuit board on which the sensor chip and the magnetic flux collecting member are mounted on a main surface,
The element forming surface of the sensor chip is parallel to the main surface of the circuit board,
The magnetic sensor according to claim 2, wherein the magnetic flux collecting member is mounted on the main surface of the circuit board without contacting the element forming surface of the sensor chip. . The sensor chip further has first and second side surfaces that are perpendicular to the main surface of the circuit board and parallel to each other,
The magnetic flux collecting member includes first and second portions that respectively cover the first and second side surfaces of the sensor chip, and a third portion that connects the first and second portions. The magnetic sensor according to claim 5, comprising: The magnetic flux collecting member includes a magnetic part made of a magnetic material and a non-magnetic part made of a non-magnetic material,
7. The magnetic sensor according to claim 5, wherein the non-magnetic portion is located between the main surface of the circuit board and the magnetic portion.