JP2019215311A - Magnetic sensor - Google Patents

Abstract

To provide a magnetic sensor having a structure in which external force applied to a magnetism collecting member is hardly transmitted to an element forming surface of a sensor chip.SOLUTION: A magnetic sensor includes a sensor chip 20 and a magnetism collecting member 30 mounted on a main surface 11 of a circuit board 10. The sensor chip 20 has an element forming surface 25 on which magnetic sensitive elements R1 and R2 are formed, and side surfaces 21 to 24 perpendicular to the main surface 11 of the circuit board 10. The magnetism collecting member 30 includes a first and a second sections 31,32 covering the side surfaces 21,22 of the sensor chip respectively, and a third section 33 connecting the first section 31 and the second section 32. According to the present invention, since the magnetism collecting member 30 has a structure not in contact with the element forming surface 25 of the sensor chip 20, even if an external force is applied to the magnetism collecting member 30, it is not transmitted to the element forming surface 25 of the sensor chip 20.SELECTED DRAWING: Figure 1

Description

  The present invention relates to a magnetic sensor, and more particularly, to a magnetic sensor having a magnetic flux collecting member for collecting magnetic flux on a sensor chip.

  Among magnetic sensors, there is a magnetic sensor provided with a magnetic flux collecting member for collecting magnetic flux on a sensor chip. For example, FIG. 5 of Patent Document 1 discloses a magnetic sensor including a sensor chip mounted on a substrate and a magnetic flux collecting member arranged on an element forming surface of the sensor chip. The magnetic flux collecting member described in Patent Literature 1 collects magnetic flux in a direction perpendicular to the substrate, and changes the direction of the magnetic flux so that the magnetic flux has a horizontal component. By detecting, the magnetic flux in the direction perpendicular to the substrate is detected.

Japanese Patent No. 5500785

  However, in the magnetic sensor described in Patent Literature 1, since the magnetic flux collecting member is arranged on the element forming surface of the sensor chip, when an external force is applied to the magnetic flux collecting member, stress is applied to the element forming surface of the sensor chip. There was such a possibility.

  Therefore, an object of the present invention is to provide a magnetic sensor having a structure in which an external force applied to the magnetic flux collecting member is not easily transmitted to the element forming surface of the sensor chip.

  The magnetic sensor according to the present invention includes a circuit board, a sensor chip and a magnetic flux collecting member mounted on a main surface of the circuit board, and the sensor chip has an element formed with a magnetically sensitive element and parallel to the main surface of the circuit board. 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, and the sensor chip is viewed from a direction perpendicular to the main surface of the circuit board. And a third portion connecting the first portion and the second portion, the first portion and the second portion being located on opposite sides of the first portion.

  According to the present invention, since the magnetic flux collecting member has a structure not in contact with the element forming surface of the sensor chip, even if an external force is applied to the magnetic flux collecting member, this is transmitted to the element forming surface of the sensor chip. There is no. Moreover, since the magnetic flux collecting member has the third portion connecting the first portion and the second portion, the magnetic flux in a predetermined direction is collected and applied to the magneto-sensitive element on the sensor chip. It is possible to do.

  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 first and second portions of the magnetic flux collecting member include the sensor chip. May be respectively covered. According to this, it is possible to apply magnetic field components in directions opposite to each other to a portion near the first side surface and a portion near the second side surface of the element formation surface.

  In the present invention, the sensor chip further has a third side surface perpendicular to the main surface of the circuit board and perpendicular to the first and second side surfaces, and the third portion of the magnetic flux collecting member is Alternatively, the third side of the sensor chip may be covered. According to this, it is possible to collect the magnetic flux in the direction parallel to the main surface of the circuit board and apply this to the magneto-sensitive element on the sensor chip.

  In the present invention, the third portion of the magnetic flux collecting member is longer in a direction parallel to the first and second side surfaces of the sensor chip than in a direction perpendicular to the first and second side surfaces of the sensor chip. The length can be longer. According to this, it is possible to increase the detection sensitivity to magnetic flux in a direction parallel to the first and second side surfaces of the sensor chip.

  In the present invention, the third portion of the magnetic flux collecting member is longer in a direction perpendicular to the first and second side surfaces of the sensor chip than in a direction parallel to the first and second side surfaces of the sensor chip. The length can be longer. According to this, it is possible to expand the magnetic flux collection range of the magnetic flux by the magnetic flux collecting member.

  In the present invention, a magnetic layer adjacent to the magneto-sensitive element may be provided on the element forming surface of the sensor chip. According to this, since the density of the magnetic flux applied to the magneto-sensitive element increases, higher detection sensitivity can be obtained.

  In the present invention, the magnetic flux collecting member may be made of a single magnetic material. According to this, it is possible to reduce the manufacturing cost of the magnetic flux collecting member. In this case, the thickness of the magnetic flux collecting member based on the main surface of the circuit board may be larger than the thickness of the sensor chip based on the main surface of the circuit board. According to this, the magnetic flux collected by the magnetic flux collecting member can be efficiently applied to the magneto-sensitive element.

  In the present invention, the magnetic flux collecting member includes a magnetic portion made of a magnetic material and a non-magnetic portion made of a non-magnetic material, the non-magnetic portion being located between the main surface of the circuit board and the magnetic portion, The height of the magnetic sensing element with respect to the main surface may be located between the height of the lower surface and the height of the upper surface of the magnetic unit with respect to the main surface of the circuit board. According to this, a thin magnetic portion such as a metal magnetic material can be used.

  In the present invention, the sensor chip may be mounted so that the element formation surface faces the main surface of the circuit board. According to this, since the element forming surface of the sensor chip is not exposed, it is possible to protect the magneto-sensitive element. In this case, the thickness of the magnetic flux collecting member based on the main surface of the circuit board may be smaller than the thickness of the sensor chip based on the main surface of the circuit board. According to this, the magnetic flux collected by the magnetic flux collecting member can be efficiently applied to the magneto-sensitive element.

  In the present invention, the third portion of the magnetic flux collecting member may cover the element forming surface of the sensor chip. According to this, it is possible to collect the magnetic flux in the direction perpendicular to the main surface of the circuit board and apply this to the magneto-sensitive element on the sensor chip.

  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 first and second portions of the magnetic flux collecting member include the sensor chip. And the gap between the first and second portions of the magnetic flux collecting member may have a stepped shape that becomes narrower at a root portion near the third portion. According to this, the magnetic flux collecting member can be manufactured using a single magnetic material.

  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 a magnetic part made of a magnetic material and a nonmagnetic material. And a first and second non-magnetic portion of the magnetic flux collecting member may cover the first and second side surfaces of the sensor chip, respectively. . According to this, even when the sensor chips having different heights are used, it is not necessary to change the design of the shape of the magnetic part.

  In the present invention, the magnetic flux collecting member may be made of a single magnetic material, and the sensor chip may be mounted such that the element forming surface faces the main surface of the circuit board. According to this, since the element forming surface of the sensor chip is not exposed, it is possible to protect the magneto-sensitive element.

  The magnetic sensor according to the present invention may further include a compensation coil wound around the third portion of the magnetic flux collecting member. According to this, since the magnetic flux taken into the magnetic flux collecting member can be canceled by the compensation coil, it is possible to prevent magnetic saturation of the magnetic flux collecting member.

  As described above, according to the present invention, in a magnetic sensor that detects magnetic flux in a direction parallel to the main surface of the circuit board, it is possible to adopt a structure in which external force applied to the magnetic flux collecting member is not easily transmitted to the element forming surface of the sensor chip. It becomes.

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 schematic side view of the magnetic sensor 1 as viewed from the y direction. FIG. 3 is a schematic diagram for explaining the flow of the magnetic flux φ. FIG. 4 is a circuit diagram showing a connection relationship between the magneto-sensitive elements R1 and R2. FIG. 5 is a schematic perspective view showing an example in which the magnetic sensor 1 is applied to the bill sensor 40. FIG. 6 is a schematic plan view showing the structure of the element forming surface 25 of the sensor chip 20A according to the first modification. FIG. 7 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. 8 is a plan view showing the shape of the magnetic flux collecting member 30A according to the first modification. FIG. 9 is a plan view showing the shape of a magnetic flux collecting member 30B according to a second modification. FIG. 10 is a schematic perspective view for explaining the structure of the magnetic sensor 2 according to the second embodiment of the present invention. FIG. 11 is a schematic perspective view for explaining the structure of the magnetic sensor 3 according to the third embodiment of the present invention. FIG. 12 is a schematic perspective view for explaining the structure of the magnetic sensor 4 according to the fourth embodiment of the present invention. FIG. 13 is a schematic side view of the magnetic sensor 4 as viewed from the y direction. FIG. 14 is a schematic perspective view for explaining the structure of the magnetic sensor 5 according to the fifth embodiment of the present invention. FIG. 15 is a schematic perspective view for explaining the structure of the magnetic sensor 6 according to the sixth embodiment of the present invention. FIG. 16 is a schematic perspective view for explaining the structure of the magnetic sensor 7 according to the seventh embodiment of the present invention. FIG. 17 is a schematic side view of the magnetic sensor 7 as viewed from the y direction. FIG. 18 is a schematic perspective view for explaining the structure of a magnetic sensor 68 according to the eighth embodiment of the present invention. FIG. 19 is a schematic side view of the magnetic sensor 68 as viewed from the y direction. FIG. 20 is a schematic perspective view for explaining the structure of the magnetic sensor 69 according to the ninth embodiment of the present invention. FIG. 21 is a schematic side view of the magnetic sensor 69 viewed from the y direction. FIG. 22 is a schematic perspective view for explaining the structure of the magnetic sensor 70 according to the tenth embodiment of the present invention. FIG. 23 is a schematic side view of the magnetic sensor 70 as viewed from the y direction. FIG. 24 is a schematic perspective view for explaining the structure of the magnetic sensor 71 according to the eleventh embodiment of the present invention. FIG. 25 is a circuit diagram for explaining the connection relationship between the magnetic sensing elements R1 to R4 and the compensation coil C. FIG. 26 is a schematic perspective view for explaining the structure of the magnetic sensor 72 according to the twelfth embodiment of the present invention. FIG. 27 is a schematic side view of the magnetic sensor 72 viewed from the y direction. FIG. 28 is a schematic perspective view for explaining the structure of the magnetic sensor 73 according to the thirteenth embodiment of the present invention. FIG. 29 is a schematic side view of the magnetic sensor 73 viewed from the y direction.

  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.

  As shown in FIG. 1, a magnetic sensor 1 according to the first embodiment includes a circuit board 10 having an xy plane as a main surface 11, a sensor chip 20 mounted on the main surface 11 of the circuit board 10, and a magnetic flux collecting member 30. And 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. The first and second portions 31 and 32 of the magnetic flux collecting member 30 are located on opposite sides with respect to the sensor chip 20 as viewed from the y direction. In the example shown in FIG. 1, 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 side surface 23 of the sensor chip 20 is completely covered by the third portion 33 of the magnetic flux collecting member 30.

  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. 2 which is a schematic side view as viewed from the y direction, the thickness H1 of the magnetic flux collecting member 30 in the z direction is greater than the thickness H2 of the sensor chip 20 in the z direction. The magnetic sensing elements R1 and R2 and the magnetic flux collecting member 30 have an overlap.

  FIG. 3 is a schematic diagram for explaining the flow of the magnetic flux φ.

  As shown in FIG. 3, the magnetic flux 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 and 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. 4, whereby the magnetic flux φ can be detected.

  In the magnetic sensor 1 according to the present embodiment, the magnetic flux collecting member 30 is provided so as to cover the side surfaces 21 to 23 of the sensor chip 20, and the element forming surface 25 of the sensor chip 20 is not covered by the magnetic flux collecting member 30. Due to the structure, 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, unless an external force is applied to the magnetic member 30 unless the element forming surface 25 of the sensor chip 20 and the magnetic flux collecting member 30 are in direct contact with each other or indirectly via an adhesive or the like. Also, this external force is not directly transmitted to the element forming surface 25 of the sensor chip 20.

  FIG. 5 is a schematic perspective view showing an example in which the magnetic sensor 1 according to the present embodiment is applied to the banknote sensor 40.

  In the bill sensor 40 shown in FIG. 5, the detection head 41 forms an xz plane, and bills (not shown) are scanned on the detection head 41 in the direction of arrow A (z direction) shown in FIG. Then, a magnetic pattern embedded in the bill is detected by the magnetic sensor 1 while scanning the bill. In order to increase the detection sensitivity in the bill sensor 40 having such a structure, it is desirable to make the gap between the bill to be measured and the magnetic flux collecting member 30 in the y direction as narrow as possible. When the gap of the y-direction 30 becomes narrow, a banknote or a foreign substance comes into contact with the detection head 41, so that an external force in the y-direction is easily applied to the magnetic flux collecting member 30.

  Even in such a case, in the magnetic sensor 1 according to the present embodiment, since the external force in the y direction applied to the magnetic flux collecting member 30 is not directly transmitted to the element forming surface 25 of the sensor chip 20, the magnetic sensor 1 is long. Even if the device is used for a period, the element forming surface 25 is hardly damaged. Thereby, the reliability of an applied product (for example, a bill sensor) using the magnetic sensor 1 according to the present embodiment can be improved.

  FIG. 6 is a schematic plan view showing the structure of the element forming 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 first modification, the magnetic layer 51 is disposed adjacent to the magnetic sensing element R1 and near the side surface 21, and the magnetic layer 52 is disposed adjacent to the magnetic sensing element R2 and near the side surface 22. Have been. 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. 7 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 second modified example, since 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 layers 51 and 52 and the magnetic layer 53 are arranged. The magnetic flux easily flows between them. 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. 8 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. 9 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 at least from a predetermined direction. It is sufficient that the first and second portions 31 and 32 of the magnetic flux collecting member 30 are located on opposite sides with respect to the sensor chip 20, and the side surface 23 of the sensor chip 20 and the third magnetic flux collecting member 30 </ b> B may be viewed. 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. 10 is a schematic perspective view for explaining the structure of the magnetic sensor 2 according to the second embodiment of the present invention.

  As shown in FIG. 10, the magnetic sensor 2 according to the second embodiment differs from the magnetic sensor 2 according to the first embodiment in that the length L2 of the magnetic flux collecting member 30 in the y direction is sufficiently longer than the width W2 in the x direction. It is different from the sensor 1. 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 sensor 2 according to the second embodiment has a feature that the detection sensitivity to the magnetic flux in the y direction is improved because the length L2 in the y direction of the magnetic flux collecting member 30 is longer than the width W2 in the x direction. I have. In particular, if the length L2 of the magnetic flux collecting member 30 in the y direction is set to be at least twice the width W2 in the x direction, for example, about three times, the effect of improving the detection sensitivity can be remarkably obtained.

<Third Embodiment>
FIG. 11 is a schematic perspective view for explaining the structure of the magnetic sensor 3 according to the third embodiment of the present invention.

  As shown in FIG. 11, the magnetic sensor 3 according to the third embodiment differs from the magnetic sensor 3 according to the first embodiment in that the width W3 of the magnetic flux collecting member 30 in the x direction is sufficiently longer than the length L3 in the y direction. It is different from the sensor 1. 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.

  In the magnetic sensor 3 according to the third embodiment, since the width W3 of the magnetic flux collecting member 30 in the x direction is longer than the length L3 in the y direction, the range of magnetic flux collected by the magnetic flux collecting member 30 in the x direction is expanded. It becomes possible.

<Fourth Embodiment>
FIG. 12 is a schematic perspective view for explaining the structure of the magnetic sensor 4 according to the fourth embodiment of the present invention.

  As shown in FIG. 12, the magnetic sensor 4 according to the fourth embodiment is different from the magnetic sensor 4 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 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. 13 which is a schematic side view seen 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 height H3 and the height H4 of the upper surface. Preferably, the height of the non-magnetic portion 30N may be set such that the height position of the magneto-sensitive elements R1 and R2 is approximately halfway between the height H3 of the lower surface and the height H4 of the upper surface.

  As a result, the magnetic flux concentrates on the magnetic portion 30M, so that the density of the magnetic flux applied to the magneto-sensitive elements R1 and R2 can be further increased. As an example, the magnetic part 30M can be made of a metal magnetic material such as permalloy, and the nonmagnetic part 30N can be made of a nonmagnetic resin. In this case, the magnetic flux collecting member 30 shown in FIG. 12 can be manufactured by processing a metal magnetic plate made of 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.

<Fifth Embodiment>
FIG. 14 is a schematic perspective view for explaining the structure of the magnetic sensor 5 according to the fifth embodiment of the present invention.

  As shown in FIG. 14, the magnetic sensor 5 according to the fifth embodiment is different from the magnetic sensor 5 shown in FIG. 10 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. This is different from the magnetic sensor 2 according to the second embodiment. Since other basic configurations are the same as those of the magnetic sensor 2 according to the second embodiment, the same components are denoted by the same reference numerals, and redundant description will be omitted.

  As described above, even when the magnetic flux collecting member 30 has a vertically long shape, the magnetic flux collecting member 30 can be configured by a combination of the magnetic portion 30M and the non-magnetic portion 30N.

<Sixth Embodiment>
FIG. 15 is a schematic perspective view for explaining the structure of the magnetic sensor 6 according to the sixth embodiment of the present invention.

  As shown in FIG. 15, the magnetic sensor 6 according to the sixth embodiment is different from the magnetic sensor 6 shown in FIG. 11 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. This is different from the magnetic sensor 3 according to the third embodiment. Since other basic configurations are the same as those of the magnetic sensor 3 according to the third embodiment, the same components are denoted by the same reference numerals, and redundant description will be omitted.

  As described above, even when the magnetic flux collecting member 30 has a horizontally long shape, the magnetic flux collecting member 30 can be configured by a combination of the magnetic portion 30M and the non-magnetic portion 30N.

<Seventh Embodiment>
FIG. 16 is a schematic perspective view for explaining the structure of the magnetic sensor 7 according to the seventh embodiment of the present invention.

  As shown in FIG. 16, the magnetic sensor 7 according to the seventh embodiment has a configuration in which the sensor chip 20 is mounted upside down on the circuit board 10 and the thickness of the magnetic flux collecting member 30 is smaller than that of the sensor chip 20. 3 is different from the magnetic sensor 1 according to the first embodiment. 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.

  In the present embodiment, the sensor chip 20 is mounted upside down so that the element forming surface 25 of the sensor chip 20 faces the main surface 11 of the circuit board 10. As a result, the heights of the magneto-sensitive elements R1 and R2 with respect to the main surface 11 of the circuit board 10 are lower than those in the first embodiment, and are located immediately above the main surface 11 of the circuit board 10. In accordance with this, in the present embodiment, the thickness of the magnetic flux collecting member 30 is sufficiently reduced. That is, as shown in FIG. 17, which is a schematic side view as viewed from the y direction, the magnetosensitive elements R1 and R2 are positioned between the main surface 11 of the circuit board 10 and the height H5 of the upper surface of the magnetic flux collecting member 30. The thickness of the magnetic flux collecting member 30 is set. Preferably, the thickness of the magnetic flux collecting member 30 may be set such that the height position of the magneto-sensitive elements R1 and R2 is approximately halfway between the main surface 11 of the circuit board 10 and the height H5 of the upper surface of the magnetic flux collecting member 30. .

  Thus, as in the fourth embodiment, the magnetic flux collecting member 30 can be manufactured by processing a metal magnetic plate made of permalloy or the like into a predetermined shape by a punching method. Further, in the present embodiment, since the element forming surface 25 of the sensor chip 20 is covered with the main surface 11 of the circuit board 10, there is an advantage that the element forming surface 25 of the sensor chip 20 is physically protected. Is also obtained.

<Eighth embodiment>
FIG. 18 is a schematic perspective view for explaining the structure of a magnetic sensor 68 according to the eighth embodiment of the present invention. FIG. 19 is a schematic side view of the magnetic sensor 68 as viewed from the y direction.

As shown in FIGS. 18 and 19, in the magnetic sensor 68 according to the eighth embodiment, the magnetic flux collecting member 30 is moved so that the third portion 33 of the magnetic flux collecting member 30 covers the element forming surface 25 of the sensor chip 20. together are mounted on the main surface 11 of the circuit board 10 to stand, in that magnetic collecting member 30 is constituted by the magnetic unit 30M and the non-magnetic portion 30 N _1, 30 N ₂ made of a nonmagnetic material made of a magnetic material, This is different from the magnetic sensor 1 according to the first embodiment shown in 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.

Collecting nonmagnetic portions 30 N ₁ of the magnetic member 30, the nonmagnetic portions 30 N ₂ of the located between the first portion 31 of the main surface 11 and the magnetic collecting member 30 of the circuit board 10, magnetic collecting member 30, the circuit board It is located between the main surface 11 of the magnetic head 10 and the second part 32 of the magnetic flux collecting member 30. Accordingly, the first and second portions 31 and 32 of the magnetic flux collecting member 30 are located on opposite sides with respect to the sensor chip 20 as viewed from the z direction. The height of the nonmagnetic portions 30N ₁ and 30N ₂ of the magnetic flux collecting member 30 in the z direction is substantially the same as the height of the sensor chip 20 in the z direction, or slightly higher than the height of the sensor chip 20 in the z direction. As a result, the leading ends of the first and second portions of the magnetic flux collecting member 30 in the z direction are located at substantially the same plane position as the element forming surface 25 of the sensor chip 20 or slightly more than the element forming surface 25 of the sensor chip 20. It is held in a high plane position.

  In the present embodiment, the element forming surface 25 of the sensor chip 20 is covered by the third portion 33 of the magnetic flux collecting member 30, but they are not in contact with each other and face each other via a space. Therefore, even if an external force is applied to the magnetic flux collecting member 30, no external force is applied to the element forming surface 25 of the sensor chip 20.

  With such a configuration, the magnetic sensor 68 according to the present embodiment can detect a magnetic flux in the z direction. That is, when the magnetic flux in the z direction is taken into the magnetic flux collecting member 30 from the third portion 33, the magnetic flux is bent in the x direction by the first and second portions 31 and 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 component in the z direction but also the component in the x direction are provided.

Thus, the magnetic sensor 68 according to the present embodiment can selectively detect the magnetic flux in the z direction. In the present embodiment, since the magnetic flux collecting member 30 has the non-magnetic portions 30N ₁ and 30N ₂ , when the sensor chips 20 having different heights are used, the non-magnetic portions are not changed without changing the shape of the magnetic portion 30M. By changing the heights of the portions 30N ₁ and 30N ₂ , it is possible to obtain appropriate characteristics.

<Ninth Embodiment>
FIG. 20 is a schematic perspective view for explaining the structure of the magnetic sensor 69 according to the ninth embodiment of the present invention. FIG. 21 is a schematic side view of the magnetic sensor 69 as viewed from the y direction.

As shown in FIGS. 20 and 21, the magnetic sensor 69 according to the ninth embodiment does not include the nonmagnetic portions 30 </ _b > N ₁ and 30 </ _b > N _{2 in the} magnetic flux collecting member 30, and includes the first and second portions 31, FIGS. 18 and 19 show that the width of the first and second portions 31 and 32 in the x direction at the root portion near the third portion 33 is not constant and the width in the x direction of the first and second portions 31 and 32 is increased. This is different from the magnetic sensor 68 according to the eighth embodiment shown. Since other basic configurations are the same as those of the magnetic sensor 68 according to the eighth embodiment, the same components are denoted by the same reference numerals, and redundant description will be omitted.

  The first portion 31 of the magnetic flux collecting member 30 has a root portion 31a and a tip portion 31b, and the width of the root portion 31a in the x direction is larger than that of the tip portion 31b. Similarly, the second portion 32 of the magnetic flux collecting member 30 has a root portion 32a and a tip portion 32b, and the width of the root portion 32a in the x direction is larger than that of the tip portion 32b. As a result, the distance between the first portion 31 and the second portion 32 in the x direction becomes a stepped shape that becomes narrower at the root portion near the third portion 33. That is, the distance Sa in the x direction between the root portion 31a and the root portion 32a is smaller than the distance Sb in the x direction between the tip portion 31b and the tip portion 32b. The boundary position in the z direction between the root portions 31a, 32a and the tip portions 31b, 32b may be designed to be substantially the same as the height of the sensor chip 20 in the z direction, or slightly higher than the height of the sensor chip 20 in the z direction. preferable.

  With such a configuration, the magnetic sensor 69 according to the present embodiment can detect a magnetic flux in the z direction. That is, when the magnetic flux in the z-direction is sucked into the magnetic flux collecting member 30 from the third portion 33, the magnetic flux is bent in the x-direction by the first and second portions 31, 32, and a part thereof is formed as the root portions 31a, 32a. It is emitted from the step portion located at the boundary between the tip portions 31b and 32b. Further, since the magnetic sensing elements R1 and R2 are arranged in the vicinity of the step in the x direction, the magnetic flux φ passing through the magnetic flux collecting member 30 is only a component in the z direction near the magnetic sensing elements R1 and R2. , But in the x-direction.

Thereby, the magnetic sensor 69 according to the present embodiment can selectively detect the magnetic flux in the z direction. In the present embodiment, since the magnetic flux collecting member 30 does not have the nonmagnetic portions 30N ₁ and 30N ₂ , it is possible to manufacture the magnetic flux collecting member 30 using a single magnetic material.

<Tenth Embodiment>
FIG. 22 is a schematic perspective view for explaining the structure of the magnetic sensor 70 according to the tenth embodiment of the present invention. FIG. 23 is a schematic side view of the magnetic sensor 70 as viewed from the y direction.

  As shown in FIGS. 22 and 23, in the magnetic sensor 70 according to the tenth embodiment, the sensor chip 20 is mounted upside down on the circuit board 10, and the first and second The difference from the magnetic sensor 69 according to the ninth embodiment is that the portions 31 and 32 do not have a step shape. Since other basic configurations are the same as those of the magnetic sensor 69 according to the ninth embodiment, the same components are denoted by the same reference numerals, and redundant description will be omitted.

  In the present embodiment, since the element forming surface 25 of the sensor chip 20 is mounted upside down so as to face the main surface 11 of the circuit board 10, the magneto-sensitive element based on the main surface 11 of the circuit board 10 is used as a reference. The heights of R1 and R2 are lower than in the ninth embodiment, and are located immediately above the main surface 11 of the circuit board 10. As a result, the tips of the first and second portions of the magnetic flux collecting member 30 in the z direction are held at substantially the same plane position as the element forming surface 25 of the sensor chip 20.

  The magnetic sensor 70 having such a configuration can also selectively detect the magnetic flux in the z direction. In the present embodiment, since the element formation surface 25 of the sensor chip 20 faces the main surface 11 of the circuit board 10, the two can be flip-chip connected, and the bonding wire can be omitted.

<Eleventh embodiment>
FIG. 24 is a schematic perspective view for explaining the structure of the magnetic sensor 71 according to the eleventh embodiment of the present invention.

  As shown in FIG. 24, the magnetic sensor 71 according to the eleventh embodiment differs from the magnetic sensor 1 according to the first embodiment in that a compensation coil C is wound around a third portion 33 of the magnetic flux collecting member 30. Is different. 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 compensating coil C is made of a wire (coating conductive) wound around the third portion 33 of the magnetic flux collecting member 30 so that the y direction is the axial direction. The compensation coil C may be wound directly around the magnetic flux collecting member 30, or may be wound around the magnetic flux collecting member 30 via a bobbin made of resin or the like. In order to prevent the winding from collapsing, the compensation coil C wound around the magnetic flux collecting member 30 may be solidified with an adhesive. In the magnetic flux collecting member 30 used in the present embodiment, the third portion 33 has a bobbin shape. This not only facilitates the work of winding the wire constituting the compensation coil C, but also prevents the compensation coil C wound around the magnetic flux collecting member 30 from falling off. In addition, in the example shown in FIG. 24, the flanges are provided at both ends in the y direction of the third portion 33, but the flanges may be provided only at one of the ends.

  The number of turns of the wire forming the compensating coil C is not particularly limited, and may be set to the number of turns necessary to generate a target cancel magnetic field. In the present embodiment, since the compensating coil C is wound around the magnetic flux collecting member 30, the number of turns can be greatly increased as compared with a method in which the compensating coil is integrated on the sensor chip 20. It is possible to pass a large current. Further, unlike the method in which a compensation coil is separately arranged on the main surface 11 of the circuit board 10, the size of the entire magnetic sensor does not increase.

  Although not particularly limited, in the present embodiment, four magneto-sensitive elements R1 to R4 are formed on the element forming surface 25 of the sensor chip 20. Of these, the magnetic sensing elements R1 and R4 are arranged offset to the side surface 21 side, and the magnetic sensing elements R2 and R3 are arranged offset to the side surface 22 side. The magneto-sensitive elements R1 to R4 all have the same magnetization fixed direction.

  FIG. 25 is a circuit diagram for explaining the connection relationship between the magnetic sensing elements R1 to R4 and the compensation coil C.

  As shown in FIG. 25, the magneto-sensitive element R1 is connected between the terminal electrodes 81 and 83, the magneto-sensitive element R2 is connected between the terminal electrodes 82 and 83, and the magneto-sensitive element R3 is connected between the terminal electrodes 81 and 84. The magneto-sensitive element R4 is connected between the terminal electrodes 82 and 84. The terminal electrode 81 is supplied with the power supply potential Vcc, and the terminal electrode 82 is supplied with the ground potential GND. Since the magneto-sensitive elements R1 to R4 all have the same magnetization fixed direction, the resistance change amounts of the magneto-sensitive elements R1 and R4 close to the first portion 31 of the magnetic flux collecting member 30 and the magnetic flux collecting members There is a difference between the resistance change amounts of the magneto-sensitive elements R2 and R3 close to the second portion 32 of 30. Thus, the magneto-sensitive elements R1 to R4 form a differential bridge circuit, and changes in the electric resistance of the magneto-sensitive elements R1 to R4 according to the magnetic flux density appear on the terminal electrodes 83 and 84.

  The differential signals output from the terminal electrodes 83 and 84 are input to a differential amplifier 91 provided on the circuit board 10 or the sensor chip 20. The output signal of the differential amplifier 91 is fed back to the terminal electrode 85. As shown in FIG. 25, a compensation coil C is connected between the terminal electrode 85 and the terminal electrode 86, whereby the compensation coil C generates a cancel magnetic field according to the output signal of the differential amplifier 91. . With such a configuration, when a change in the electric resistance of the magneto-sensitive elements R1 to R4 according to the magnetic flux density of the external magnetic flux appears on the terminal electrodes 83 and 84, a current corresponding thereto flows through the compensation coil C, and the cancel magnetic field in the opposite direction. Generate. Thereby, the external magnetic flux is canceled out. Then, if the current output from the differential amplifier 91 is converted into a current voltage by the detection circuit 92, the intensity of the external magnetic flux can be detected.

  In the present embodiment, since the compensating coil C is wound around the magnetic flux collecting member 30, a sufficient number of turns can be ensured and a larger current can flow. Thereby, since a strong canceling magnetic field can be generated, even when the magnetic field to be measured is relatively strong, not only can the magnetic field applied to the magneto-sensitive elements R1 to R4 be correctly canceled, It is possible to prevent magnetic saturation of the magnetic flux collecting member 30.

<Twelfth Embodiment>
FIG. 26 is a schematic perspective view for explaining the structure of the magnetic sensor 72 according to the twelfth embodiment of the present invention. FIG. 27 is a schematic side view of the magnetic sensor 72 viewed from the y direction.

  As shown in FIGS. 26 and 27, the magnetic sensor 72 according to the twelfth embodiment has the compensation coil C wound around the third portion 33 of the magnetic flux collecting member 30 and the element forming surface of the sensor chip 20. 25 is different from the magnetic sensor 68 according to the eighth embodiment in that four magnetic sensing elements R1 to R4 are formed. Since other basic configurations are the same as those of the magnetic sensor 68 according to the eighth embodiment, the same components are denoted by the same reference numerals, and redundant description will be omitted.

  In the present embodiment, the magnetic flux collecting member 30 is mounted upright on the main surface 11 of the circuit board 10 so that the third portion 33 of the magnetic flux collecting member 30 covers the element forming surface 25 of the sensor chip 20. The compensating coil C is wound around the third portion 33 of the magnetic flux collecting member 30 such that the z direction is the axial direction. Thereby, the magnetic flux in the z direction taken into the third portion 33 of the magnetic flux collecting member 30 can be canceled. Thus, similarly to the magnetic sensor 71 according to the eleventh embodiment, even when the magnetic field to be measured is relatively strong, not only can the magnetic field applied to the magneto-sensitive elements R1 to R4 be correctly canceled, but also In addition, magnetic saturation of the magnetic flux collecting member 30 can be prevented.

<13th Embodiment>
FIG. 28 is a schematic perspective view for explaining the structure of the magnetic sensor 73 according to the thirteenth embodiment of the present invention. FIG. 29 is a schematic side view of the magnetic sensor 73 as viewed from the y direction.

  As shown in FIGS. 28 and 29, the magnetic sensor 73 according to the thirteenth embodiment has a compensation coil C wound around a third portion 33 of a magnetic flux collecting member 30 and an element forming surface of a sensor chip 20. 25 is different from the magnetic sensor 70 according to the tenth embodiment in that four magnetic sensing elements R1 to R4 are formed. Since other basic configurations are the same as those of the magnetic sensor 70 according to the tenth embodiment, the same components are denoted by the same reference numerals, and redundant description will be omitted.

  Also in the present embodiment, the magnetic flux in the z direction taken into the third portion 33 of the magnetic flux collecting member 30 can be canceled by the compensation coil C. As a result, similarly to the magnetic sensors 71 and 72 according to the embodiments of FIGS. 11 and 12, even when the magnetic field to be measured is relatively strong, the magnetic field applied to the magneto-sensitive elements R1 to R4 is correctly canceled. In addition to this, the magnetic saturation of the magnetic flux collecting member 30 can be prevented.

  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 to 7, 68 to 73 Magnetic sensor 10 Circuit board 11 Main surface 20, 20A, 20B of circuit board Sensor chip 21 to 24 Side surface 25 Element formation surface 26 Back surface 30, 30A, 30B Magnetic flux collecting member 30M Magnetic portion 30N, 30N ₁ , 30N ₂ Non-magnetic part 31 First part 32 Second part 33 Third part 31a, 32a Root part 31b, 32b Tip part 40 Bill sensor 41 Detection head 81-86 Terminal electrode 91 Differential amplifier 92 Detection circuit 51 To 53 Magnetic layer C Compensation coil R1 to R4 Magnetic sensing element φ Magnetic flux

Claims (16)

A circuit board,
A sensor chip and a magnetic flux collecting member mounted on the main surface of the circuit board,
The sensor chip has a magneto-sensitive element formed thereon, and has an element forming surface parallel to the main surface of the circuit board,
The magnetic flux collecting member is mounted on the main surface of the circuit board without being in contact with the element forming surface of the sensor chip, and viewed from a direction perpendicular to the main surface of the circuit board, A magnetic sensor comprising: first and second portions located on opposite sides with respect to a sensor chip; and a third portion connecting the first portion and the second portion. 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 sensor according to claim 1, wherein the first and second portions of the magnetic flux collecting member cover the first and second side surfaces of the sensor chip, respectively. The sensor chip is perpendicular to the main surface of the circuit board, and further has a third side surface perpendicular to the first and second side surfaces,
The magnetic sensor according to claim 2, wherein the third portion of the magnetic flux collecting member covers the third side surface of the sensor chip.   The third portion of the magnetic flux collecting member is more parallel to the first and second side surfaces of the sensor chip than a length of the sensor chip in a direction perpendicular to the first and second side surfaces. The magnetic sensor according to claim 3, wherein the length in the direction is longer.   The third portion of the magnetic flux collecting member is more perpendicular to the first and second side surfaces of the sensor chip than the length of the sensor chip in a direction parallel to the first and second side surfaces. The magnetic sensor according to claim 3, wherein the length in the direction is longer.   The magnetic sensor according to claim 3, wherein the magnetic flux collecting member is made of a single magnetic material.   The thickness of the magnetic flux collecting member based on the main surface of the circuit board is greater than the thickness of the sensor chip based on the main surface of the circuit board. Magnetic sensor. 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,
The non-magnetic portion is located between the main surface of the circuit board and the magnetic portion,
The height of the magneto-sensitive element with respect to the main surface of the circuit board is located between the height of the lower surface and the height of the upper surface of the magnetic unit with respect to the main surface of the circuit board. The magnetic sensor according to claim 3, wherein:   8. The magnetic sensor according to claim 1, wherein the sensor chip is mounted such that the element forming surface faces the main surface of the circuit board. 9.   10. The sensor according to claim 9, wherein a thickness of the magnetic flux collecting member with respect to the main surface of the circuit board is smaller than a thickness of the sensor chip with respect to the main surface of the circuit board. Magnetic sensor.   The magnetic sensor according to claim 1, wherein the third portion of the magnetic flux collecting member covers 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 first and second portions of the magnetic flux collecting member cover the first and second side surfaces of the sensor chip, respectively.
The magnetic sensor according to claim 11, wherein an interval between the first and second portions of the magnetic flux collecting member has a stepped shape that becomes narrower at a root portion near the third portion. 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 a magnetic part made of a magnetic material and first and second nonmagnetic parts made of a nonmagnetic material,
The magnetic sensor according to claim 11, wherein the first and second nonmagnetic portions of the magnetic flux collecting member cover the first and second side surfaces of the sensor chip, respectively. The magnetic flux collecting member is made of a single magnetic material,
The magnetic sensor according to claim 11, wherein the sensor chip is mounted such that the element formation surface faces the main surface of the circuit board.   The magnetic sensor according to claim 1, wherein a magnetic layer adjacent to the magneto-sensitive element is provided on the element forming surface of the sensor chip.   The magnetic sensor according to claim 1, further comprising a compensation coil wound around the third portion of the magnetic flux collecting member.

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