JP2022046892A - Magnetic sensor - Google Patents

Abstract

To provide a compact magnetic sensor that can correctly cancel a magnetic field applied to magneto-sensitive elements with a compensation coil and can prevent magnetic saturation of an external magnetic body.SOLUTION: A magnetic sensor 1 comprises: a sensor chip 20; an external magnetic body 30; a compensation coil C wound around the external magnetic body 30; and a molding member 50 that holds connection pins P1, P2. The compensation coil C is connected at both ends with the connection pins P1, P2. This allows efficient application of a cancellation magnetic field to the external magnetic body 30. In addition, the connection of the compensation coil C at both ends with the connection P1, P2 facilitates connection of the compensation coil C and a feedback circuit with each other.SELECTED DRAWING: Figure 1

Description

The present invention relates to a magnetic sensor, and more particularly to a magnetic sensor including an external magnetic material that collects magnetic flux in a magnetic sensing element and a compensation coil.

As a magnetic sensor provided with an external magnetic material that collects magnetic flux in a magnetic sensing element and a compensation coil, the magnetic sensors described in Patent Documents 1 and 2 are known. The magnetic sensor described in Patent Documents 1 and 2 includes a magnetic sensing element and a compensation coil integrated in the sensor chip, and an external magnetic material arranged on the sensor chip. Then, the magnetic field collected by the external magnetic material is applied to the magnetic sensing element, and the magnetic field applied to the magnetic sensing element is canceled by the compensation coil, so that so-called closed loop control is performed. As a result, the magnetic field applied to the magnetic field element is always maintained at zero, so that an offset due to a temperature change or the like does not occur, and accurate magnetic field measurement becomes possible.

However, in the magnetic sensors described in Patent Documents 1 and 2, it is difficult to secure a sufficient number of turns of the compensation coil because the compensation coil has a structure integrated in the sensor chip. Therefore, the magnetic field generated from the current flowing through the compensation coil is relatively small. Therefore, when the magnetic field to be measured is relatively strong, it is difficult to cancel the magnetic field applied to the magnetic sensing element. Further, since the compensation coil and the external magnetic material are separated from each other, it is conceivable that the external magnetic material is magnetically saturated when the magnetic field to be measured is strong. When the external magnetic material is magnetically saturated, there is a problem that the linearity between the strength of the magnetic field and the sensor output is lost due to the decrease in the magnetic collecting ability, and accurate magnetic field measurement cannot be performed.

As a method for solving such a problem, as shown in FIG. 12 of Patent Document 1, a method of separately adding a large compensating coil that surrounds the sensor chip is conceivable on the substrate on which the sensor chip is mounted. .. According to this method, a strong canceling magnetic field can be applied to the magnetically sensitive element and the external magnetic material, so that the magnetic field applied to the magnetically sensitive element can be correctly applied even when the magnetic field to be measured is relatively strong. It can be canceled and magnetic saturation of the external magnetic material can be prevented.

International Publication No. 2017/07787 Pamphlet Japanese Unexamined Patent Publication No. 2018-179738

However, the method of mounting a large compensation coil on the substrate has a problem that the size of the entire magnetic sensor becomes large.

Therefore, an object of the present invention is to provide a small magnetic sensor capable of correctly canceling a magnetic field applied to a magnetic sensing element by a compensating coil and preventing magnetic saturation of an external magnetic material. And.

The magnetic sensor according to the present invention has a sensor chip having at least one magnetically sensitive element, a first external magnetic material that collects a magnetic field to be detected on the magnetically sensitive element, and compensation wound around the first external magnetic material. It comprises a coil and a first molding member fixed to a first external magnetic material and holding the first and second connecting pins, one end of the compensating coil being connected to the first connecting pin and of the compensating coil. The other end is characterized in that it is connected to a second connection pin.

According to the present invention, since the compensating coil is wound around the first external magnetic material, the coil diameter can be reduced. Therefore, it is possible to efficiently apply the canceling magnetic field to the external magnetic material while preventing the size of the entire magnetic sensor from increasing in size. As a result, the magnetic field applied to the magnetic sensing element can be correctly canceled, and the magnetic saturation of the first external magnetic material can be prevented. Further, since the compensating coil does not have to be arranged as a separate component, the change in the canceling magnetic field due to the misalignment of the compensating coil or the like is reduced, and the sensor can be provided with a stable yield. Moreover, since the first molding member is fixed to the first external magnetic material and both ends of the compensation coil are connected to the first and second connection pins held by the first molding member, the compensation coil is connected. And the feedback circuit can be easily connected.

In the present invention, the sensor chip is mounted on the surface of the substrate so that the element forming surface on which the magnetic sensitive element is formed is perpendicular to the surface of the substrate or has a predetermined inclination, and the first external magnetic material is the surface of the substrate. It may be installed in. According to this, even when the length of the external magnetic material is long, the external magnetic material can be stably supported on the substrate.

In the present invention, the first and second connection pins may be connected to the first and second terminal electrodes provided on the substrate, respectively. According to this, since the compensation coil and the first and second terminal electrodes are connected via the first and second connection pins, it is not necessary to solder the compensation coil directly to the terminal electrodes on the substrate. The work efficiency of assembly work is improved.

In the present invention, the first connecting pin has first and second protrusions protruding from the first molding member, and the second connecting pin has third and fourth protrusions protruding from the first molding member. It has a protrusion, one end of the compensating coil is fixed to the first protruding portion of the first connecting pin, and the other end of the compensating coil is fixed to the third protruding portion of the second connecting pin. The terminal electrode may be connected to the second protrusion of the first connection pin and the second terminal electrode may be connected to the fourth protrusion of the second connection pin. This facilitates the connection between the connection pin and the compensation coil and the terminal electrode.

In the present invention, the first protruding portion of the first connecting pin and the third protruding portion of the second connecting pin may protrude from each other in the same direction. According to this, when both ends of the compensating coil are fixed to the connection pin by soldering, the soldering work can be completed in one time. In this case, the first protruding portion of the first connecting pin and the third protruding portion of the second connecting pin may have different height positions from the surface of the substrate. According to this, both ends of the compensation coil can be connected to the first and third protrusions without interfering with each other.

In the present invention, the first protruding portion of the first connecting pin and the third protruding portion of the second connecting pin may protrude in opposite directions to each other. According to this, even if the height positions of the first and third protrusions are the same, both ends of the compensating coil can be connected to the first and third protrusions without interfering with each other. It will be possible.

The magnetic sensor according to the present invention may further include first and second wiring patterns provided on the back surface or inner layer of the substrate and connected to the first and second terminal electrodes, respectively. According to this, it is possible to reduce the influence of the noise generated from the wiring pattern on the magnetic sensing element. In this case, the first and second wiring patterns may have a coplanar structure or a microstrip line structure. According to this, it becomes possible to further reduce the influence of noise.

The magnetic sensor according to the present invention is mounted on the surface of the substrate and is attached to a second external magnetic body located on the side opposite to the first external magnetic body when viewed from the sensor chip, and to the first and second connection pins, respectively. It may further include first and second wires that are connected and placed on the second external magnetic material. According to this, it is possible to further reduce the influence of the noise generated by the current flowing through the compensating coil on the magnetic sensing element. In this case, the first and second wires may intersect the second external magnetic material multiple times. This makes it possible to reduce the variation in inductance and the variation in impedance.

In the present invention, the external magnetic material has a width portion fixed to the surface of the substrate and a width detail having a cross-sectional area smaller than that of the width portion, and the compensation coil may be wound around the width detail. do not have. According to this, it is possible to prevent the interference between the substrate and the compensation coil.

The magnetic sensor according to the present invention may further include a second molding member fixed to the tip of the width detail. This makes it possible to prevent the compensation coil from falling off from the external magnetic material. In this case, the second molded member may have a hooking portion for hooking the compensation coil. According to this, since the folded position of the compensating coil is fixed, it is possible to prevent the compensating coil from unwinding.

In the present invention, the wide portion may have a first wide portion located on one end side of the width detail and a second wide portion located on the other end side of the width detail. This makes it possible to prevent the compensation coil from falling off from the external magnetic material.

In the present invention, the first molded member may be positioned by a step between the wide portion and the width detail. According to this, it is possible to fix the positional relationship between the external magnetic material and the first molding member.

As described above, according to the present invention, there is provided a small magnetic sensor capable of correctly canceling the magnetic field applied to the magnetic sensing element by the compensation coil and preventing magnetic saturation of the external magnetic material. It becomes possible to do.

FIG. 1 is a schematic perspective view showing the appearance of the magnetic sensor 1 according to the first embodiment of the present invention. FIG. 2 is a substantially disassembled perspective view of the magnetic sensor 1. FIG. 3 is a schematic plan view of the sensor chip 20. FIG. 4 is a schematic cross-sectional view taken along the line AA of FIG. FIG. 5 is a schematic cross-sectional view for explaining an example in which the magnetic material layer and the magnetic sensing element have an overlap. FIG. 6 is a circuit diagram for explaining the connection relationship between the magnetic sensing elements R1 to R4 and the compensation coil C. FIG. 7A is a schematic perspective view for explaining the shape of the molded member 50. FIG. 7B is a schematic perspective view for explaining the shape of the molded member 50. FIG. 7C is a schematic perspective view for explaining the shape of the molded member 50. FIG. 8A is a schematic perspective view for explaining the shape of the molded member 60. FIG. 8B is a schematic perspective view for explaining the shape of the molded member 60. FIG. 9 is a schematic diagram for explaining the role of the hooking portion 61. FIG. 10 is a schematic diagram showing an example in which the wiring patterns 13 and 14 have a coplanar structure. FIG. 11 is a schematic diagram showing an example in which the wiring patterns 13 and 14 have a microstrip line structure. FIG. 12 is a schematic perspective view showing the appearance of the magnetic sensor 2 according to the second embodiment of the present invention. FIG. 13A is a schematic perspective view for explaining the shape of the molded member 80. FIG. 13B is a schematic perspective view for explaining the shape of the molded member 80. FIG. 13C is a schematic perspective view for explaining the shape of the molded member 80. FIG. 14 is a schematic perspective view showing the appearance of the magnetic sensor 3 according to the third embodiment of the present invention. FIG. 15 is a schematic diagram for explaining the shape of the external magnetic body 30 used in the third embodiment. FIG. 16 is a schematic perspective view showing the appearance of the magnetic sensor 4 according to the fourth embodiment of the present invention. FIG. 17A is a schematic perspective view for explaining the shape of the molded member 90. FIG. 17B is a schematic perspective view for explaining the shape of the molded member 90. FIG. 17C is a schematic perspective view for explaining the shape of the molded member 90.

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 showing the appearance of the magnetic sensor 1 according to the first embodiment of the present invention. Further, FIG. 2 is a substantially disassembled perspective view of the magnetic sensor 1.

As shown in FIGS. 1 and 2, the magnetic sensor 1 according to the first embodiment includes a substrate 10, a sensor chip 20 mounted on a surface 11 constituting the xz surface of the substrate 10, and external magnetic bodies 30, 40. The compensating coil C wound around the external magnetic body 30 and the molding members 50 and 60 fixed to the external magnetic body 30 are provided. The sensor chip 20 has an element forming surface 21 and a back surface 22 constituting the xy surface, side surfaces 23 and 24 constituting the yz surface, and side surfaces 25 and 26 constituting the xz surface, and the side surface 26 is a substrate. It is mounted on the substrate 10 so as to face the surface 11 of the 10. A magnetic sensitive element and magnetic material layers M1 to M3, which will be described later, are formed on the element forming surface 21 of the sensor chip 20. As described above, in the present embodiment, the surface 11 of the substrate 10 and the element forming surface 21 of the sensor chip 20 are perpendicular to each other. However, in the present invention, it is not essential that the two are completely vertical, and they may have a predetermined inclination with respect to the vertical.

The external magnetic bodies 30 and 40 play a role of collecting magnetic flux in the sensor chip 20, and are both made of a high magnetic permeability material such as ferrite. Of these, the external magnetic body 30 is a rod-shaped body whose longitudinal direction is the z direction, and is positioned substantially at the center of the element forming surface 21 in the x direction so as to cover a part of the magnetic body layer M1. The external magnetic body 40 is located on the side opposite to the external magnetic body 30 when viewed from the sensor chip 20. The external magnetic material 40 covers a part of the magnetic material layers M2 and M3, and also covers the side surfaces 23, 24 and the back surface 22 of the sensor chip 20, and has a rod-like shape with the z direction as the longitudinal direction. With this configuration, the magnetic field in the z direction is selectively magnetized, and the magnetic field collected is applied to the sensor chip 20.

The external magnetic body 30 has a wide portion 31 fixed to the surface 11 of the substrate 10 and a width detail 32 having a cross-sectional area of xy cross section smaller than that of the wide portion 31. The width detail 32 is separated from the surface 11 of the substrate 10.

The compensation coil C is composed of a wire (coated conductor wire) wound around the width detail 32 of the external magnetic body 30 so that the z direction is the axial direction. In the present embodiment, the compensation coil C is directly wound around the external magnetic body 30. Further, in order to prevent the winding from collapsing, the compensation coil C wound around the external magnetic body 30 may be hardened with an adhesive or the like. The number of turns of the wire constituting the compensation coil C is not particularly limited, and may be the number of turns required to generate the target cancel magnetic field. In the present embodiment, since the compensation coil C is wound around the external magnetic body 30, the number of turns can be significantly increased as compared with the method of integrating the compensation coil on the sensor chip 20, and more. It is possible to pass a large current. Further, unlike the method in which the compensation coil is separately arranged on the substrate, the size of the entire magnetic sensor does not increase.

The molding members 50 and 60 are made of a non-magnetic insulating material such as resin, and both are fixed to the external magnetic body 30 using an adhesive or the like. Of these, the molding member 50 is provided so as to cover the step 33 located at the boundary between the wide thick portion 31 and the width detail 32 of the external magnetic body 30, and the molding member 60 is provided at the tip of the width detail 32. The structures and roles of the molded members 50 and 60 will be described in detail later.

FIG. 3 is a schematic plan view of the sensor chip 20, and FIG. 4 is a schematic cross-sectional view taken along the line AA of FIG.

As shown in FIGS. 3 and 4, four magnetic sensing elements R1 to R4 are formed on the element forming surface 21 of the sensor chip 20. The magnetic sensing elements R1 to R4 are not particularly limited as long as they are elements whose electrical resistance changes depending on the direction of the magnetic flux, and for example, an MR element or the like can be used. The fixed magnetization directions of the magnetic sensing elements R1 to R4 are aligned with each other (for example, the plus side in the x direction). The magnetic sensitive elements R1 to R4 are covered with an insulating layer 27, and magnetic material layers M1 to M3 made of permalloy or the like are formed on the surface of the insulating layer 27. The magnetic layers M1 to M3 are covered with an insulating layer 28. Of the magnetic layers M1 to M3, the portion located on one side (upper side in FIG. 3) in the y direction is defined as the magnetic material layers M11, M21, M31, and the other side in the y direction (lower side in FIG. 3). ) Is defined as the magnetic material layers M12, M22, and M32, the magnetic sensory element R1 is located between the magnetic material layer M11 and the magnetic material layer M21 in a plan view (viewed from the z direction). The magnetic sensor R2 is located between the magnetic layer M12 and the magnetic layer M22, the magnetic sensor R3 is located between the magnetic layer M11 and the magnetic layer M31, and the magnetic sensor R4 is located between the magnetic layer M12 and the magnetic layer M12. It is located between the magnetic layers M32. As a result, the magnetic field passing through the magnetic gaps G1 to G4 is applied to the magnetic sensing elements R1 to R4.

However, in the present invention, it is not essential that the magnetic sensitive elements R1 to R4 are located between the two magnetic material layers in a plan view, and the vicinity of the magnetic gaps G1 to G4 composed of the two magnetic material layers, that is, the magnetic gap. It suffices if the magnetic sensing elements R1 to R4 are arranged on the magnetic path formed by G1 to G4. Further, the width of the magnetic gaps G1 to G4 does not have to be wider than the width of the magnetic sensing elements R1 to R4, and the width of the magnetic gaps G1 to G4 may be narrower than the width of the magnetic sensing elements R1 to R4. In the example shown in FIG. 5, the width Gx of the magnetic gap G1 in the x direction is narrower than the width Rx of the magnetic sensor R1 in the x direction, whereby the magnetic material layers M1 and M2 and the magnetic sensor R1 are viewed from the z direction. Have an overlapping OV. The relationship between the magnetic gaps G1 to G4 and the magnetic sensing elements R1 to R4 may be the relationship shown in FIG.

In FIGS. 3 and 4, the regions indicated by reference numerals 30a and 40a indicate regions covered by the external magnetic materials 30 and 40, respectively. As shown in FIGS. 3 and 4, the external magnetic material 30 covers the magnetic material layer M1, and the external magnetic material 40 covers the magnetic material layers M2 and M3.

FIG. 6 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. 6, the magnetic sensor R1 is connected between the terminal electrodes T11 and T13, the magnetic sensor R2 is connected between the terminal electrodes T12 and T14, and the magnetic sensor R3 is connected between the terminal electrodes T11 and T12. The magnetic sensory element R4 is connected between the terminal electrodes T13 and T14. The terminal electrodes T11 to T14 are terminal electrodes constituting the terminal electrode group T10 shown in FIG. The terminal electrode group T10 is provided on the sensor chip 20 and is connected to the terminal electrode group T30 shown in FIGS. 1 and 2 via a wiring (not shown) formed on the substrate 10. A power supply potential Vcc is given to the terminal electrode T11, and a ground potential GND is given to the terminal electrode T14. Since all the magnetic sensing elements R1 to R4 have the same magnetization fixing direction, the resistance change amount of the magnetic sensing elements R1 and R2 located on one side of the external magnetic body 30 and the external magnetic body 30 There is a difference between the resistance changes of the magnetic sensing elements R3 and R4 located on the other side of the magnetism. As a result, the magnetic sensing elements R1 to R4 form a differential bridge circuit, and changes in the electrical resistance of the magnetic sensing elements R1 to R4 according to the magnetic flux density appear as differential signals Va on the terminal electrodes T12 and T13. ..

The differential signal Va output from the terminal electrodes T12 and T13 is input to the differential amplifier 71 provided on the substrate 10 or the sensor chip 20. The output signal of the differential amplifier 71 is fed back to the terminal electrode T21. As shown in FIG. 6, a compensating coil C is connected between the terminal electrode T21 and the terminal electrode T22, whereby the compensating coil C generates a canceling magnetic field corresponding to the output signal of the differential amplifier 71. .. The terminal electrodes T21 and T22 are connected to connection pins P1 and P2 held by the molding member 50, respectively. With this configuration, when the differential signal Va corresponding to the change in the electrical resistance of the magnetic sensing elements R1 to R4 according to the magnetic flux density of the magnetic field to be detected appears on the terminal electrodes T12 and T13, the corresponding current is applied to the compensation coil C. To generate a canceling magnetic field in the opposite direction. As a result, the magnetic field to be detected is canceled. Then, if the current output from the differential amplifier 71 is converted into current and voltage by the detection circuit 72, the strength of the magnetic field to be detected can be detected. Such closed-loop control makes it possible to detect the magnetic field collected via the external magnetic bodies 30 and 40 with high accuracy.

Further, in the present embodiment, since the compensation coil C is wound around the external magnetic body 30, a sufficient number of turns can be secured and a larger current can be passed. As a result, a strong canceling magnetic field can be generated, so that even when the magnetic field to be measured is relatively strong, not only the magnetic fields applied to the magnetic sensing elements R1 to R4 can be correctly canceled, but also the magnetic fields applied to the magnetic sensing elements R1 to R4 can be correctly canceled. It is possible to prevent magnetic saturation of the external magnetic material 30.

Moreover, in the present embodiment, since the external magnetic body 30 has the width thick portion 31 and the width detail 32, and the compensation coil C is wound around the width detail 32, the compensation coil C and the substrate 10 are wound. No contact or interference occurs. As a result, the wide portion 31 of the external magnetic body 30 can be brought into close contact with the surface 11 of the substrate 10, so that the external magnetic body 30 can be stably fixed to the surface 11 of the substrate 10.

7A to 7C are schematic perspective views for explaining the shape of the molded member 50, and show states viewed from different angles.

As shown in FIGS. 7A to 7C, the molding member 50 includes a holding mechanism 51 for holding the connection pin P1, a holding mechanism 52 for holding the connection pin P2, and a guide groove 53 for guiding one end of the compensation coil C. A guide groove 54 for guiding the other end of the compensation coil C and a slit 55 fitted with the external magnetic body 30 are provided. The connection pins P1 and P2 are held by the molding member 50 by being inserted into the holding mechanisms 51 and 52, respectively, and are preferably positioned. The connection pins P1 and P2 may be adhered to the molding member 50 by using an adhesive or the like.

The connection pins P1 and P2 have protrusions P1a and P2a protruding in the −x direction from the surface of the molding member 50 and protrusions P1b and P2b protruding in the −y direction from the surface of the molding member 50. The protrusions P1a and P2a are connected to one end and the other end of the compensation coil C, respectively, and the protrusions P1b and P2b are connected to the terminal electrodes T21 and T22, respectively.

The protrusions P1a and P2a are connected to the compensation coil C by winding one end and the other end of the compensation coil C from which the insulating coating has been removed around the protrusions P1a and P2a, respectively, and fixing them with solder. At this time, since the protruding portions P1a and P2a protrude from the surface of the molding member 50, it is possible to easily perform the winding work and the soldering work of the compensation coil C. In particular, the soldering work can be completed once by winding one end and the other end of the compensating coil C around the protrusions P1a and P2a, respectively, and then immersing the protrusions P1a and P2a in the solder bath. ..

On the other hand, as shown in FIG. 2, the protruding portions P1b and P2b are inserted into the through holes T21a and T22a provided in the substrate 10 and soldered so as to be provided around or on the inner wall of the through holes T21a and T22a. It is connected to the terminal electrodes T21 and T22, respectively.

Further, the protruding portion P1a of the connecting pin P1 and the protruding portion P2a of the connecting pin P2 have different height positions from the surface 11 of the substrate 10. As a result, the guide grooves 53 and 54 of the compensation coil C can be provided at different height positions, so that the vicinity of both ends of the compensation coil can be guided to the protrusions P1a and P2a without interfering with each other. Become.

The external magnetic material 30 is inserted into the slit 55 of the molding member 50. Here, the slit 55 has a wide portion 55a having a width of W1 in the x direction and a narrow portion 55b having a width of W2 (<W1) in the x direction, and the wide portion 55a has an external magnetic material 30. The wide portion 31 of the above is inserted, and the width detail 32 of the external magnetic body 30 is inserted into the narrow portion 55b. Then, when the external magnetic body 30 is inserted into the slit 55 of the molding member 50, the step 33 of the external magnetic body 30 and the step 56 in the slit 55 interfere with each other, whereby the molding member 50 z with respect to the external magnetic body 30. Positioned in the direction.

8A and 8B are schematic perspective views for explaining the shape of the molded member 60, and show a state in which they are visually recognized from different angles.

As shown in FIGS. 8A and 8B, the molding member 60 includes a hooking portion 61 for hooking the compensation coil C and a cavity 62 for fitting the tip of the external magnetic body 30. In the example shown in FIG. 1, the compensating coil C is also wound around the molding member 60, but this point is not essential in the present invention. Further, the hooking portion 61 serves to hold the folded portion of the compensation coil C in the z direction. That is, as shown in FIG. 9, which is a schematic diagram, since the connection pins P1 and P2 to which both ends of the compensation coil C are connected are both held by the molding member 50, the portion where the molding member 60 is arranged. The compensation coil C will be folded back at. By hooking such a folded-back portion on the hooking portion 61, it is possible to prevent unwinding at the folded-back portion of the compensation coil C.

In the magnetic sensor 1 according to the present embodiment, the molded members 50 and 60 are fixed to the external magnetic body 30 in advance, the compensating coil C is wound, and the connection pins P1 and P2 are connected to the compensating coil C before being connected. It can be manufactured by mounting the external magnetic material 30 on the substrate 10 so that the protruding portions P1b and P2b of the pins P1 and P2 are inserted into the through holes T21a and T22a. This eliminates the need to directly solder both ends of the compensation coil C to the substrate 10, so that the magnetic sensor 1 can be efficiently manufactured.

The terminal electrodes T21 and T22 are connected to the terminal electrode group T30 via a wiring pattern provided on the substrate 10. The wiring pattern may be provided on the surface 11 of the substrate 10, but in order to reduce the influence of noise generated from the wiring pattern on the magnetic sensitive elements R1 to R4, the wiring pattern may be provided on the back surface or the inner layer of the substrate 10. It is preferable to provide it. In this case, as shown in FIG. 10, wiring patterns 13 and 14 connected to the terminal electrodes T21 and T22 are provided on the back surface 12 of the substrate 10, and on the back surface 12 of the substrate 10 so as to sandwich the wiring patterns 13 and 14. If the coplanar structure is provided by providing the ground pattern 15, the influence of noise can be further reduced. Alternatively, as shown in FIG. 11, wiring patterns 13 and 14 connected to the terminal electrodes T21 and T22 are provided on the back surface 12 of the substrate 10, and a ground pattern is provided on the inner layer of the substrate 10 so as to overlap the wiring patterns 13 and 14. If the microstrip line structure is provided by providing 16, the influence of noise can be further reduced.

As described above, in the magnetic sensor 1 according to the present embodiment, since the compensation coil C is wound around the external magnetic body 30, the canceling magnetic field can be efficiently applied to the external magnetic body 30. Further, since the molding member 50 is fixed to the external magnetic body 30 and both ends of the compensation coil C are connected to the connection pins P1 and P2 held by the molding member 50, the compensation coil and the feedback circuit can be easily connected. Become.

<Second embodiment>
FIG. 12 is a schematic perspective view showing the appearance of the magnetic sensor 2 according to the second embodiment of the present invention.

As shown in FIG. 12, the magnetic sensor 2 according to the second embodiment is different from the magnetic sensor 1 according to the first embodiment in that the molding member 80 is used instead of the molding member 50. Since the other basic configurations are the same as those of the magnetic sensor 1 according to the first embodiment, the same elements are designated by the same reference numerals, and duplicate description will be omitted.

13A to 13C are schematic perspective views for explaining the shape of the molded member 80, and show states viewed from different angles.

As shown in FIGS. 13A to 13C, the molding member 80 includes a holding mechanism 81 for holding the connection pin P1, a holding mechanism 82 for holding the connection pin P2, and a guide groove 83 for guiding one end of the compensation coil C. A guide groove 84 for guiding the other end of the compensation coil C and a slit 85 for fitting with the external magnetic body 30 are provided. The connection pins P1 and P2 are held by the molding member 80 by being inserted into the holding mechanisms 81 and 82, respectively, and are preferably positioned. The connection pins P1 and P2 may be adhered to the molding member 80 by using an adhesive or the like.

The connection pin P1 has a protrusion P1a protruding from the surface of the molding member 80 in the −x direction and a protrusion P1b protruding from the surface of the molding member 80 in the −y direction. The connection pin P2 has a protruding portion P2a protruding from the surface of the molding member 80 in the + x direction and a protruding portion P2b protruding from the surface of the molding member 80 in the −y direction. The protrusions P1a and P2a are connected to one end and the other end of the compensation coil C, respectively, and the protrusions P1b and P2b are connected to the terminal electrodes T21 and T22, respectively.

The protrusions P1a and P2a are connected to the compensation coil C by winding one end and the other end of the compensation coil C from which the insulating coating has been removed around the protrusions P1a and P2a, respectively, and fixing them with solder. At this time, since the protruding portions P1a and P2a protrude from the surface of the molding member 80, it is possible to easily perform the winding work and the soldering work of the compensation coil C.

If the molding member 80 used in the present embodiment is used, the protruding portion P1a of the connecting pin P1 and the protruding portion P2a of the connecting pin P2 project in opposite directions to each other, so that the height positions of the protruding portions P1a and P2a are the same. Even if there is, both ends of the compensation coil C can be guided to the protrusions P1a and P2a without interfering with each other.

The external magnetic material 30 is inserted into the slit 85 of the molding member 80. Here, the slit 85 has a wide portion 85a having a width of W1 in the x direction and a narrow portion 85b having a width of W2 (<W1) in the x direction, and the wide portion 85a has an external magnetic material 30. The wide portion 31 of the above is inserted, and the width detail 32 of the external magnetic body 30 is inserted into the narrow portion 85b. Then, when the external magnetic body 30 is inserted into the slit 85 of the molding member 80, the step 33 of the external magnetic body 30 and the step 86 in the slit 85 interfere with each other, whereby the molding member 80 z with respect to the external magnetic body 30. Positioned in the direction.

<Third embodiment>
FIG. 14 is a schematic perspective view showing the appearance of the magnetic sensor 3 according to the third embodiment of the present invention.

As shown in FIG. 14, the magnetic sensor 3 according to the third embodiment is different from the magnetic sensor 1 according to the first embodiment in that the molding member 60 is omitted and the shape of the external magnetic body 30 is different. It's different. Since the other basic configurations are the same as those of the magnetic sensor 1 according to the first embodiment, the same elements are designated by the same reference numerals, and duplicate description will be omitted.

FIG. 15 is a schematic diagram for explaining the shape of the external magnetic body 30 used in the present embodiment.

As shown in FIG. 15, the external magnetic body 30 used in the present embodiment has a width detail 32 and width thick portions 31, 34 located on both sides of the width detail 32. The thick portions 31 and 34 are portions in contact with the surface 11 of the substrate 10, and the width details 32 are portions away from the surface 11 of the substrate 10. Then, the compensation coil C is wound around the width detail 32 of the external magnetic body 30 so that the z direction is the axial direction. The external magnetic body 30 has a step 33 located at the boundary between the width detail 32 and the wide thick portion 31, and a step 35 located at the boundary between the wide detail 32 and the wide thick portion 34, and these steps 33 and 35. Prevents the compensation coil C from falling off.

As described above, according to the present embodiment, it is possible to prevent the compensation coil C from falling off from the external magnetic body 30 without using the molding member 60.

<Fourth Embodiment>
FIG. 16 is a schematic perspective view showing the appearance of the magnetic sensor 4 according to the fourth embodiment of the present invention.

As shown in FIG. 16, in the magnetic sensor 4 according to the fourth embodiment, the molding member 90 is used instead of the molding member 50, and the wires W1 and W2 connecting the connection pins P1 and P2 and the connector 100 are connected. It is different from the magnetic sensor 1 according to the first embodiment in that it is provided. Since the other basic configurations are the same as those of the magnetic sensor 1 according to the first embodiment, the same elements are designated by the same reference numerals, and duplicate description will be omitted.

17A to 17C are schematic perspective views for explaining the shape of the molded member 90, and show states viewed from different angles.

As shown in FIGS. 17A to 17C, the molding member 90 includes a holding mechanism 91 for holding the connection pin P1, a holding mechanism 92 for holding the connection pin P2, a guide groove 93 for guiding one end of the compensation coil C, and a guide groove 93. It includes a guide groove 94 that guides the other end of the compensation coil C, and a slit 95 that fits into the external magnetic body 30. In the present embodiment, the connection pins P1 and P2 are substantially U-shaped, and the projecting portions P1a, P1b, P2a, and P2b all project in the + y direction. The connection pins P1 and P2 are held by the molding member 90 by being inserted into the holding mechanisms 91 and 92, respectively, and are preferably positioned. The connection pins P1 and P2 may be adhered to the molding member 90 by using an adhesive or the like.

The protrusions P1a and P2a are connected to one end and the other end of the compensation coil C, respectively, and the protrusions P1b and P2b are connected to one ends of the wires W1 and W2, respectively. For the connection between the protrusions P1a and P2a and the compensation coil C, and the connection between the protrusions P1b and P2b and the wires W1 and W2, the ends of the compensation coil C and the wires W1 and W2 from which the insulating coating has been removed are connected to the protrusions P1a and P1a, respectively. This is done by winding it around P2a, P1b, P2b and fixing it with solder. At this time, since the projecting portions P1a, P2a, P1b, and P2b project from the surface of the molding member 90, the compensating coil C and the wires W1 and W2 can be easily wound and soldered. ..

The wires W1 and W2 are arranged on the external magnetic body 40 and intersect the external magnetic body 40 a plurality of times. As described above, in the present embodiment, since the connection pins P1 and P2 and the connector 100 are connected by using the wires W1 and W2 instead of using the wiring pattern of the substrate 10, the current flowing through the compensation coil C It is possible to reduce the influence of the noise generated by the above on the magnetic sensing elements R1 to R4. Moreover, if the wires W1 and W2 are twisted, it is possible to reduce the variation in inductance and the variation in impedance.

Further, in the present embodiment, since it is not necessary to provide the through holes T21a and T22a in the substrate 10 and insert the connection pins P1 and P2 into the through holes T21a and T22a, the assembly work becomes easy.

Although the preferred embodiment of the present invention has been described above, the present invention is not limited to the above embodiment, and various modifications can be made without departing from the gist of the present invention, and these are also the present invention. Needless to say, it is included in the range.

1 to 4 Magnetic sensor 10 Substrate 11 Substrate front surface 12 Substrate back surface 13, 14 Wiring pattern 15, 16 Ground pattern 20 Sensor chip 21 Element forming surface 22 Sensor chip back surface 23 to 26 Sensor chip side surface 27, 28 Insulation layer 30 , 40 External magnetic material 30a, 40a Area covered with external magnetic material 31,34 Width Thick part 32 Width detail 33, 35 Step 50, 60 Molding member 51, 52 Holding mechanism 53, 54 Guide groove 55 Slit 55a Wide part 55b Width Narrow part 56 Step 61 Hooking part 62 Cavity 71 Differential amplifier 72 Detection circuit 80 Molding member 81, 82 Holding mechanism 83, 84 Guide groove 85 Slit 85a Wide part 85b Wide part 86 Step 90 Molding member 91, 92 Holding mechanism 93 , 94 Guide groove 95 Slit 100 Connector C Compensation coil G1 to G4 Magnetic gap M1 to M3, M11, M21, M31, M12, M22, M32 Magnetic material layer P1, P2 Connection pins P1a, P2a, P1b, P2b Projections R1 to R4 Magnetic element T10, T30 Terminal electrode group T11 to T14, T21, T22 Terminal electrodes T21a, T22a Through holes W1, W2 Wire

Claims (16)

With a sensor chip having at least one magnetoreceptive element,
A first external magnetic material that collects the magnetic field to be detected on the magnetically sensitive element, and
The compensating coil wound around the first external magnetic material and
A first molded member fixed to the first external magnetic material and holding the first and second connecting pins.
A magnetic sensor characterized in that one end of the compensation coil is connected to the first connection pin and the other end of the compensation coil is connected to the second connection pin. The sensor chip is mounted on the surface of the substrate so that the element forming surface on which the magnetic sensing element is formed is perpendicular to the surface of the substrate or has a predetermined inclination.
The magnetic sensor according to claim 1, wherein the first external magnetic material is mounted on the surface of the substrate. The magnetic sensor according to claim 2, wherein the first and second connection pins are connected to the first and second terminal electrodes provided on the substrate, respectively. The first connecting pin has first and second protrusions protruding from the first molding member.
The second connecting pin has third and fourth protrusions that project from the first molding member.
The one end of the compensating coil is fixed to the first protrusion of the first connecting pin.
The other end of the compensating coil is fixed to the third protrusion of the second connecting pin.
The first terminal electrode is connected to the second protrusion of the first connection pin.
The magnetic sensor according to claim 3, wherein the second terminal electrode is connected to the fourth protrusion of the second connection pin. The magnetic sensor according to claim 4, wherein the first protruding portion of the first connecting pin and the third protruding portion of the second connecting pin project in the same direction from each other. 5. The fifth aspect of the present invention is characterized in that the first protruding portion of the first connecting pin and the third protruding portion of the second connecting pin have different height positions from the surface of the substrate. The magnetic sensor described. The magnetic sensor according to claim 4, wherein the first protruding portion of the first connecting pin and the third protruding portion of the second connecting pin project in opposite directions to each other. The invention according to any one of claims 3 to 7, further comprising first and second wiring patterns provided on the back surface or the inner layer of the substrate and connected to the first and second terminal electrodes, respectively. The magnetic sensor described. The magnetic sensor according to claim 8, wherein the first and second wiring patterns have a coplanar structure or a microstrip line structure. A second external magnetic material mounted on the surface of the substrate and located on the side opposite to the first external magnetic material when viewed from the sensor chip.
The magnetism according to claim 2, further comprising first and second wires connected to the first and second connection pins and arranged on the second external magnetic material, respectively. Sensor. The magnetic sensor according to claim 10, wherein the first and second wires intersect the second external magnetic material a plurality of times. The first external magnetic material has a thick portion fixed to the surface of the substrate and a width detail having a cross-sectional area smaller than that of the thick portion.
The magnetic sensor according to any one of claims 2 to 11, wherein the compensating coil is wound around the width detail. 12. The magnetic sensor according to claim 12, further comprising a second molding member fixed to the tip of the width detail. The magnetic sensor according to claim 13, wherein the second molded member has a hooking portion for hooking the compensation coil. 12. The twelfth aspect of claim 12, wherein the wide portion has a first wide portion located on one end side of the width detail and a second wide portion located on the other end side of the width detail. Magnetic sensor. The magnetic sensor according to any one of claims 12 to 15, wherein the first molded member is positioned by a step between the wide portion and the width detail.

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