JP7115242B2 - magnetic sensor - Google Patents

Description

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

Among magnetic sensors, there is a magnetic sensor equipped 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 magnetism collecting member arranged on the element forming surface of the sensor chip. The magnetic flux collecting member described in Patent Document 1 collects the magnetic flux in the direction perpendicular to the substrate, changes the direction of the magnetic flux to give the magnetic flux a horizontal component, and detects the horizontal component of the magnetic flux by the magneto-sensitive element. By detecting, the magnetic flux in the direction perpendicular to the substrate is detected.

Japanese Patent No. 5500785

However, in the magnetic sensor disclosed in Patent Document 1, since the magnetic collecting member is arranged on the element forming surface of the sensor chip, when an external force is applied to the magnetic collecting member, stress is applied to the element forming surface of the sensor chip. It could take.

SUMMARY OF THE INVENTION Accordingly, it is an object of the present invention to provide a magnetic sensor having a structure in which an external force applied to a magnetic flux collecting member is less likely to be transmitted to an element forming surface of a sensor chip.

A magnetic sensor according to the present invention comprises a circuit board, and a sensor chip and a magnetism collecting member mounted on the main surface of the circuit board. The magnetic flux collecting member has a formation surface, and is mounted on the main surface of the circuit board without contacting the element formation surface of the sensor chip. and a third portion connecting the first portion and the second portion.

According to the present invention, since the magnetic collecting member has a structure that does not come into contact with the element forming surface of the sensor chip, even if an external force is applied to the magnetic collecting member, it 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 becomes possible to

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

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

In the present invention, the third portion of the magnetic flux collecting member is longer than the length in the direction perpendicular to the first and second side surfaces of the sensor chip. It doesn't matter if the length is longer. According to this, it is possible to increase the detection sensitivity for the magnetic flux in the 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 than the length in the direction parallel to the first and second side surfaces of the sensor chip. It doesn't matter if the length is longer. According to this, it becomes possible to expand the magnetic flux collection range of 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, it is possible to obtain higher detection sensitivity.

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 relative to the main surface of the circuit board may be greater than the thickness of the sensor chip relative to the main surface of the circuit board. According to this, it is possible to efficiently apply the magnetic flux collected by the magnetic collecting member 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 is positioned between the main surface of the circuit board and the magnetic portion. The height of the magneto-sensitive element relative to the main surface may be between the height of the lower surface and the upper surface of the magnetic portion relative to the main surface of the circuit board. According to this, it becomes possible to use a thin magnetic part such as a metal magnetic body.

In the present invention, the sensor chip may be mounted so 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. In this case, the thickness of the magnetic flux collecting member with respect to the main surface of the circuit board may be thinner than the thickness of the sensor chip with respect to the main surface of the circuit board. According to this, it is possible to efficiently apply the magnetic flux collected by the magnetic collecting member 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 becomes possible to collect the magnetic flux in the direction perpendicular to the main surface of the circuit board and apply it 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 parallel to each other, and the first and second portions of the magnetic flux collecting member are the sensor chip The gap between the first and second portions of the magnetic flux collecting member may have a stepped shape that narrows at the root portion near the third portion. According to this, it is possible to manufacture the magnetic flux collecting member using a single magnetic material.

In the present invention, the sensor chip is perpendicular to the main surface of the circuit board and further has first and second side surfaces parallel to each other, and the magnetic flux collecting member includes a magnetic portion made of a magnetic material and a non-magnetic material. The first and second nonmagnetic portions of the magnetic flux collecting member may cover the first and second side surfaces of the sensor chip, respectively. . According to this, even when using sensor chips having different heights, it is not necessary to change the design of the shape of the magnetic portion.

In the present invention, the magnetic flux collecting member may be made of a single magnetic material, and the sensor chip may be mounted so 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 comprise a compensating coil wound around the third portion of the magnetic collecting member. According to this, since the magnetic flux taken into the magnetic flux collecting member can be canceled by the compensating coil, it is possible to prevent the 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 a circuit board, it is possible to provide a structure in which an external force applied to the magnetic flux collecting member is less likely to be transmitted to the element forming surface of the sensor chip. becomes.

FIG. 1 is a schematic perspective view for explaining the structure of a magnetic sensor 1 according to a first embodiment of the invention. FIG. 2 is a schematic side view of the magnetic sensor 1 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 the connection relationship between the magneto-sensitive elements R1 and R2. FIG. 5 is a schematic see-through perspective view showing an example in which the magnetic sensor 1 is applied to a bill sensor 40. As shown in FIG. 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 modified example. 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 a magnetic flux collecting member 30A according to the first modified example. FIG. 9 is a plan view showing the shape of a magnetic flux collecting member 30B according to the 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 invention. FIG. 11 is a schematic perspective view for explaining the structure of the magnetic sensor 3 according to the third embodiment of the invention. FIG. 12 is a schematic perspective view for explaining the structure of the magnetic sensor 4 according to the fourth embodiment of the invention. FIG. 13 is a schematic side view of the magnetic sensor 4 as seen 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 invention. FIG. 15 is a schematic perspective view for explaining the structure of the magnetic sensor 6 according to the sixth embodiment of the invention. FIG. 16 is a schematic perspective view for explaining the structure of the magnetic sensor 7 according to the seventh embodiment of the invention. FIG. 17 is a schematic side view of the magnetic sensor 7 viewed from the y direction. FIG. 18 is a schematic perspective view for explaining the structure of the magnetic sensor 68 according to the eighth embodiment of the invention. FIG. 19 is a schematic side view of the magnetic sensor 68 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 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 invention. FIG. 23 is a schematic side view of the magnetic sensor 70 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 invention. FIG. 25 is a circuit diagram for explaining the connection relationship between the magneto-sensitive elements R1 to R4 and the compensating coil C. As shown in FIG. FIG. 26 is a schematic perspective view for explaining the structure of the magnetic sensor 72 according to the twelfth embodiment of the 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 invention. FIG. 29 is a schematic side view of the magnetic sensor 73 viewed from the y direction.

Preferred embodiments of the present invention will now be described in detail with reference to the accompanying drawings.

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

As shown in FIG. 1, the magnetic sensor 1 according to the first embodiment includes a circuit board 10 having an xy plane as a main surface 11, and a sensor chip 20 and a magnetic flux collecting member 30 mounted on the main surface 11 of the circuit board 10. and The sensor chip 20 has side surfaces 21 and 22 forming the yz plane, side surfaces 23 and 24 forming the xz plane, and an element formation surface 25 and a back surface 26 forming the xy plane. It is mounted on the circuit board 10 so as to face the main surface 11 of the board 10 . The sensor chip 20 can be fixed by applying an adhesive between the circuit board 10 and the rear surface 26 of the sensor chip 20 . Also, the electrical connection between the sensor chip 20 and the circuit board 10 can be made using a bonding wire or the like (not shown).

Two magneto-sensitive elements R1 and R2 are formed on the element forming surface 25 . As the magneto-sensitive elements R1 and R2, magneto-resistive elements 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 surface 21 and the magneto-sensitive element R2 is arranged near the side surface 22. As shown in FIG.

The magnetic flux collecting member 30 is a block made of a single magnetic material such as ferrite, and has first and second portions 31 and 32 covering the side surfaces 21 and 22 of the sensor chip 20, respectively. 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 of the sensor chip 20 as viewed in 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 partially cover the side surfaces 21 and 22 of the sensor chip 20, respectively. It may be a shape that completely covers. Also, the side surface 23 of the sensor chip 20 is completely covered with the third portion 33 of the magnetic flux collecting member 30 .

The magnetic flux collecting member 30 serves to collect the magnetic flux in the y-direction by the third portion 33 and distribute it to the first and second portions 31 and 32 . As shown in FIG. 2, which is a schematic side view in the y direction, the thickness H1 of the magnetic flux collecting member 30 in the z direction is thicker than the thickness H2 of the sensor chip 20 in the z direction. As can be seen, the magneto-sensitive elements R1 and R2 and the magnetism collecting member 30 overlap each other.

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

As shown in FIG. 3, the y-direction magnetic flux is drawn 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 magnetism collecting member 30 in the x direction, the magnetic flux φ passing through the magnetism collecting member 30 is In the vicinity of the magneto-sensitive elements R1 and R2, there are not only y-direction components but also x-direction components.

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, the x-direction component of the magnetic flux φ sucked into the magnetic flux collecting member 30 is opposite between the magneto-sensitive element R1 and the magneto-sensitive element R2. A difference will occur in the value. Such a difference in resistance value is taken out as an output signal Vout from the series circuit shown in FIG. 4, thereby making it possible to detect the magnetic flux φ.

The magnetic sensor 1 according to the present embodiment is provided with the magnetic collecting member 30 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 with the magnetic collecting member 30. Due to the structure, even if an external force is applied to the magnetic flux collecting member 30 , this external force will not be 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 forming surface 25 of the sensor chip 20 may be partially covered with the magnetism collecting member 30 . Even in this case, as long as the element forming surface 25 of the sensor chip 20 and the magnetic collecting member 30 are not in direct contact with each other or indirectly through an adhesive or the like, even if an external force is applied to the magnetic member 30, However, this external force is not directly transmitted to the element formation surface 25 of the sensor chip 20 .

FIG. 5 is a schematic see-through perspective view showing an example in which the magnetic sensor 1 according to this embodiment is applied to a bill sensor 40. As shown in FIG.

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

Even in such a case, in the magnetic sensor 1 according to the present embodiment, 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, so the magnetic sensor 1 can be lengthened. Even if it is used for a period of time, the element forming surface 25 is less likely to be damaged. This makes it possible to improve the reliability of an application product (for example, a bill sensor) using the magnetic sensor 1 according to this embodiment.

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 modified example. A sensor chip 20</b>A according to the first modification differs from the sensor chip 20 described above in that magnetic layers 51 and 52 are formed on the element forming surface 25 . The magnetic layers 51 and 52 may be films made of a composite magnetic material in which magnetic filler is dispersed in a resin material, or thin films or foils made of a soft magnetic material such as nickel or permalloy. It may be a thin film or bulk sheet made of ferrite or the like. Further, the magnetic layers 51 and 52 may be positioned above the magneto-sensitive elements R1 and R2, may be positioned below them, or may be positioned on the same layer.

In the first modification, the magnetic layer 51 is arranged adjacent to the magneto-sensitive element R1 and near the side surface 21, and the magnetic layer 52 is arranged adjacent to the magneto-sensitive element R2 and near the side surface 22. It is As a result, since the magnetic resistance in the vicinity of the magneto-sensitive elements R1 and R2 is lowered, 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 modified example differs from the sensor chip 20A according to the first modified example 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 positioned above the magneto-sensitive elements R1 and R2, may be positioned below them, or may be positioned on the same layer.

In the second modification, since the magnetic layer 53 is sandwiched between the magneto-sensitive elements R1 and R2 in the x direction, the magnetic layers 51 and 52 and the magnetic layer 53 Magnetic flux flows easily between As a result, 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 a magnetic flux collecting member 30A according to the first modified example. In the magnetic flux collecting member 30A according to the first modification, both side surfaces are cut in a tapered shape so that the width in the x direction of the first and second portions 31 and 32 becomes narrower toward the tip. It is different from the magnetism collecting member 30 described above. According to this, since the magnetic flux φ taken in from the third portion 33 is collected by the magneto-sensitive elements R1 and R2 by the tapered first and second portions 31 and 32, the magneto-sensitive elements R1 and R2 It becomes possible to apply the magnetic flux φ of the x-direction component to .

FIG. 9 is a plan view showing the shape of a magnetic flux collecting member 30B according to the second modification. The magnetism collecting member 30B according to the second modification is substantially C-shaped in plan view, and differs from the magnetism collecting member 30 described above in that the third portion 33 is largely separated from the side surface 23 of the sensor chip 20. is 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 adjacent to each other. Looking at it, it is sufficient that the first and second portions 31 and 32 of the magnetic flux collecting member 30 are positioned on opposite sides of the sensor chip 20, and the side surface 23 of the sensor chip 20 and the third portion of the magnetic flux collecting member 30B are sufficient. 33 may be spaced apart. In this structure as well, the magnetic flux φ taken in from the third portion 33 is applied to the magneto-sensitive elements R1 and R2 through the first and second portions 31 and 32, and the magneto-sensitive elements R1 and R2 It is possible to increase the x-direction component of the magnetic flux φ applied to .

<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 invention.

As shown in FIG. 10, in the magnetic sensor 2 according to the second embodiment, the magnetic field collector 30 has a length L2 in the y direction sufficiently longer than a width W2 in the x direction. It is different from Sensor 1. Since other basic configurations are the same as those of the magnetic sensor 1 according to the first embodiment, the same elements are denoted by the same reference numerals, and overlapping descriptions are omitted.

The magnetic sensor 2 according to the second embodiment is characterized in that the y-direction length L2 of the magnetic flux collecting member 30 is longer than the x-direction width W2, thereby improving the detection sensitivity for magnetic flux in the y-direction. there is In particular, if the length L2 in the y direction of the magnetic flux collecting member 30 is set to be twice or more, for example, about three times the width W2 in the x direction, it is possible to significantly improve the detection sensitivity.

<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 invention.

As shown in FIG. 11, in the magnetic sensor 3 according to the third embodiment, 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 Sensor 1. Since other basic configurations are the same as those of the magnetic sensor 1 according to the first embodiment, the same elements are denoted by the same reference numerals, and overlapping descriptions are omitted.

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

As shown in FIG. 12, the magnetic sensor 4 according to the fourth embodiment differs from the first embodiment in that the magnetic collecting member 30 includes a magnetic portion 30M made of a magnetic material and a nonmagnetic portion 30N made of a nonmagnetic material. It is different from the magnetic sensor 1 by Since other basic configurations are the same as those of the magnetic sensor 1 according to the first embodiment, the same elements are denoted by the same reference numerals, and overlapping descriptions are omitted.

The magnetic portion 30</b>M of the magnetic flux collecting member 30 is a portion that collects magnetic flux in the y direction and applies it to the magnetic sensitive elements R<b>1 and R<b>2 of the sensor chip 20 . On the other hand, the non-magnetic portion 30N of the magnetism 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 equal to the height of the magneto-sensitive elements R1 and R2. It is a part that plays a role of raising up to. That is, as shown in FIG. 13, which is a schematic side view seen from the y-direction, the non-magnetic portion 30N present below the magnetic portion 30M causes the lower surface of the magnetic portion 30M with the main surface 11 of the circuit board 10 as a reference to be displaced. The height of the magnetic portion 30M is maintained so that the magneto-sensitive elements R1 and R2 are positioned between the height H3 and the height H4 of the upper surface. Preferably, the height of the non-magnetic portion 30N should be set so that the height positions of the magneto-sensitive elements R1 and R2 are approximately midway between the height H3 of the lower surface and the height H4 of the upper surface.

As a result, the magnetic flux is concentrated in 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 portion 30M can be made of a metallic magnetic material such as Permalloy, and the non-magnetic portion 30N can be made of a non-magnetic resin. In this case, the magnetism collecting member 30 shown in FIG. 12 can be manufactured by punching a metal magnetic plate made of permalloy or the like into a predetermined shape and attaching it to resin. When the magnetic portion 30M is produced by punching a metal magnetic plate such as permalloy, the thickness of the magnetic portion 30M is constant, whereas the thickness of the sensor chip 20 may vary depending on the product. Even in such a case, the height of the magnetic portion 30M can be maintained at a desired height by changing the thickness of the non-magnetic 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 invention.

As shown in FIG. 14, the magnetic sensor 5 according to the fifth embodiment is different from that shown in FIG. It differs 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 elements are denoted by the same reference numerals, and overlapping descriptions are omitted.

Thus, even when the magnetism collecting member 30 has a vertically long shape, it is possible to configure the magnetism collecting member 30 by combining 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 invention.

As shown in FIG. 15, the magnetic sensor 6 according to the sixth embodiment is different from that shown in FIG. It differs from the magnetic sensor 3 according to the third embodiment. Other basic configurations are the same as those of the magnetic sensor 3 according to the third embodiment.

Thus, even when the magnetic flux collecting member 30 has a laterally long shape, the magnetic flux collecting member 30 can be configured by combining 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 invention.

As shown in FIG. 16, in the magnetic sensor 7 according to the seventh embodiment, the sensor chip 20 is mounted upside down on the circuit board 10, and the magnetic flux collecting member 30 is thinner than the sensor chip 20. 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 elements are denoted by the same reference numerals, and overlapping descriptions are omitted.

In this 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 height of the magneto-sensitive elements R1 and R2 with respect to the main surface 11 of the circuit board 10 is lower than in the first embodiment, and is located directly above the main surface 11 of the circuit board 10. FIG. Accordingly, in this embodiment, the thickness of the magnetic flux collecting member 30 is made sufficiently thin. That is, as shown in FIG. 17, which is a schematic side view seen from the y-direction, the magneto-sensitive 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 magnetism collecting member 30. The thickness of the magnetism collecting member 30 is set. Preferably, the thickness of the magnetism collecting member 30 should be set so that the height positions of the magnetism sensing elements R1 and R2 are approximately midway between the main surface 11 of the circuit board 10 and the height H5 of the upper surface of the magnetism collecting member 30. .

Thus, similarly to the fourth embodiment, the magnetic flux collecting member 30 can be manufactured by punching a metal magnetic plate made of permalloy or the like into a predetermined shape. 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 the magnetic sensor 68 according to the eighth embodiment of the invention. 19 is a schematic side view of the magnetic sensor 68 as seen 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 arranged such that the third portion 33 of the magnetic flux collecting member 30 covers the element forming surface 25 of the sensor chip 20. In that it is vertically mounted on the main surface 11 of the circuit board 10 and that the magnetic flux collecting member 30 is composed of the magnetic portion 30M made of a magnetic material and the non-magnetic portions 30N ₁ and 30N ₂ made of a non-magnetic material, It differs 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 elements are denoted by the same reference numerals, and overlapping descriptions are omitted.

The nonmagnetic portion 30N1 of the magnetic flux collecting member 30 is positioned between the main surface 11 of the circuit board 10 and the _first portion 31 of the magnetic flux collecting member 30, and the nonmagnetic portion _30N2 of the magnetic flux collecting member 30 is positioned between the circuit board 10 and the second portion 32 of the magnetic collecting member 30 . As a result, the first and second portions 31 and 32 of the magnetic flux collecting member 30 are located on opposite sides of the sensor chip 20 when viewed in 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 approximately 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 ends of the first and second portions of the magnetic flux collecting member 30 in the z-direction are located at substantially the same planar position as the element forming surface 25 of the sensor chip 20 or slightly above the element forming surface 25 of the sensor chip 20 . It is held in a high planar position.

In this embodiment, the element forming surface 25 of the sensor chip 20 is covered with the third portion 33 of the magnetic flux collecting member 30, but they are not in contact with each other and face each other with a space therebetween. Therefore, even if an external force is applied to the magnetic flux collecting member 30 , the external force is not applied to the element forming surface 25 of the sensor chip 20 .

With such a configuration, the magnetic sensor 68 according to this embodiment can detect 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, it is bent in the x direction by the first and second portions 31 and 32. FIG. Since the magneto-sensitive elements R1 and R2 are arranged near the first and second portions 31 and 32 of the magnetism collecting member 30 in the x direction, the magnetic flux φ passing through the magnetism collecting member 30 is In the vicinity of the magneto-sensitive elements R1 and R2, there are not only z-direction components but also x-direction components.

As a result, the magnetic sensor 68 according to this embodiment can selectively detect the magnetic flux in the z direction. In this embodiment, since the magnetic flux collecting member 30 has the non-magnetic portions 30N ₁ and 30N ₂ , when using the sensor chips 20 having different heights, the non-magnetic portion 30M can be adjusted without changing the shape of the magnetic portion 30M. Appropriate characteristics can be obtained by varying the heights of the portions 30N ₁ and 30N ₂ .

<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 invention. 21 is a schematic side view of the magnetic sensor 69 as seen from the y direction.

As shown in FIGS. 20 and 21, in the magnetic sensor 69 according to the ninth embodiment, the non-magnetic portions 30N ₁ and 30N ₂ are not provided in the magnetic flux collecting member 30, and the first and second portions 31 and 30N2 are not provided. 18 and 19 in that the width in the x direction of 32 is not constant and the width in the x direction of the first and second portions 31 and 32 is enlarged at the root portion near the third portion 33. It differs 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 elements are denoted by the same reference numerals, and overlapping descriptions are omitted.

The first portion 31 of the magnetic flux collecting member 30 has a base portion 31a and a tip portion 31b, and the base portion 31a is wider in the x direction than 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 root portion 32a is wider in the x direction than the tip portion 32b. As a result, the interval in the x direction between the first portion 31 and the second portion 32 has a stepped shape that narrows at the root portion near the third portion 33 . That is, the distance Sa between the root portion 31a and the root portion 32a in the x direction is narrower than the distance Sb between the tip portion 31b and the tip portion 32b in the x direction. The boundary positions in the z direction between the root portions 31a and 32a and the tip portions 31b and 32b can be designed to be approximately 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 this embodiment can detect magnetic flux in the z direction. That is, when the magnetic flux in the z-direction is drawn into the magnetic flux collecting member 30 from the third portion 33, it is bent in the x-direction by the first and second portions 31 and 32, and part of it becomes the root portions 31a and 32a. It is emitted from the step portion located at the boundary between the tip portions 31b and 32b. Since the magneto-sensitive elements R1 and R2 are arranged in the vicinity of the step portion in the x-direction, the magnetic flux φ passing through the magnetic flux collecting member 30 is limited to the z-direction component in the vicinity of the magneto-sensitive elements R1 and R2. will have an x-direction component instead of

As a result, the magnetic sensor 69 according to this embodiment can selectively detect the magnetic flux in the z direction. In this embodiment, since the magnetic flux collecting member 30 does not have the non-magnetic portions 30N ₁ and 30N ₂ , the magnetic flux collecting member 30 can be manufactured from 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 invention. 23 is a schematic side view of the magnetic sensor 70 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 on the circuit board 10 upside down, and the first and second magnetic flux collecting members 30 It differs from the magnetic sensor 69 according to the ninth embodiment in that the portions 31 and 32 do not have a stepped shape. Other basic configurations are the same as those of the magnetic sensor 69 according to the ninth embodiment.

In this embodiment, since the sensor chip 20 is mounted upside down so that the element formation surface 25 of the sensor chip 20 faces the main surface 11 of the circuit board 10, the magneto-sensitive element is mounted with the main surface 11 of the circuit board 10 as a reference. The heights of R1 and R2 are lower than those of the ninth embodiment, and are located directly above the main surface 11 of the circuit board 10 . As a result, the ends of the first and second portions of the magnetic flux collecting member 30 in the z direction are held at substantially the same planar 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 this embodiment, since the element forming 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 bonding wires 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 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 the compensating coil C is wound around the third portion 33 of the magnetic flux collecting member 30 . is different from Since other basic configurations are the same as those of the magnetic sensor 1 according to the first embodiment, the same elements are denoted by the same reference numerals, and overlapping descriptions are omitted.

The compensating coil C consists of a wire (coated conductor) wound around the third portion 33 of the magnetic collecting member 30 so that the y-direction is the axial direction. The compensating coil C may be wound directly around the magnetic collecting member 30, or may be wound around the magnetic collecting member 30 via a bobbin made of resin or the like. Moreover, in order to prevent winding collapse, the compensating coil C wound around the magnetism collecting member 30 may be fixed with an adhesive. The magnetism collecting member 30 used in this embodiment has a third portion 33 having a bobbin shape. This not only facilitates the work of winding the wire forming the compensating coil C, but also prevents the compensating coil C wound around the magnetic flux collecting member 30 from coming off. In the example shown in FIG. 24, the flanges are provided on both ends of the third portion 33 in the y direction, but the flanges may be provided on only one of the ends.

The number of turns of the wire forming the compensation coil C is not particularly limited, and may be the number of turns required to generate the desired canceling magnetic field. In this embodiment, since the compensating coil C is wound around the magnetic flux collecting member 30, it is possible to greatly increase the number of turns compared to the method in which the compensating coil is integrated in the sensor chip 20, and the number of turns can be increased. It is possible to pass a large current. Moreover, unlike the system in which the 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 this embodiment, four magneto-sensitive elements R1 to R4 are formed on the element forming surface 25 of the sensor chip 20. FIG. Among them, the magneto-sensitive elements R1 and R4 are arranged offset to the side 21 side, and the magneto-sensitive elements R2 and R3 are arranged to be offset to the side 22 side. The magneto-sensitive elements R1 to R4 all have the same fixed magnetization direction.

FIG. 25 is a circuit diagram for explaining the connection relationship between the magneto-sensitive elements R1 to R4 and the compensating coil C. As shown in FIG.

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. , and the magneto-sensitive element R4 is connected between the terminal electrodes 82,84. Terminal electrode 81 is supplied with power supply potential Vcc, and terminal electrode 82 is supplied with ground potential GND. Since the magneto-sensitive elements R1 to R4 all have the same fixed magnetization direction, the amount of resistance change of the magneto-sensitive elements R1 and R4 near the first portion 31 of the magnetism collecting member 30 and the magnetism collecting member There is a difference between the resistance change amounts of the magneto-sensitive elements R2 and R3 near the second portion 32 of 30 . As a result, the magneto-sensitive elements R1-R4 form a differential bridge circuit, and the terminal electrodes 83 and 84 show changes in electrical resistance of the magneto-sensitive elements R1-R4 in accordance with the magnetic flux density.

A differential signal output from the terminal electrodes 83 and 84 is input to a differential amplifier 91 provided on the circuit board 10 or the sensor chip 20 . An output signal of the differential amplifier 91 is fed back to the terminal electrode 85 . As shown in FIG. 25, a compensating coil C is connected between the terminal electrodes 85 and 86, whereby the compensating coil C generates a canceling magnetic field corresponding to the output signal of the differential amplifier 91. . With such a configuration, when the terminal electrodes 83 and 84 show a change in the electric resistance of the magneto-sensitive elements R1 to R4 corresponding to the magnetic flux density of the external magnetic flux, the corresponding current flows through the compensating coil C, causing a canceling magnetic field in the opposite direction. generate This cancels the external magnetic flux. Then, if the current output from the differential amplifier 91 is current-voltage converted by the detection circuit 92, the strength of the external magnetic flux can be detected.

In this embodiment, since the compensating coil C is wound around the magnet collecting member 30, a sufficient number of turns can be ensured and a larger current can flow. As a result, since a strong canceling magnetic field can be generated, even if 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 canceled correctly, It becomes 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 invention. 27 is a schematic side view of the magnetic sensor 72 as seen from the y direction.

As shown in FIGS. 26 and 27, in the magnetic sensor 72 according to the twelfth embodiment, the compensating coil C is wound around the third portion 33 of the magnetic flux collecting member 30, and the element formation surface of the sensor chip 20 is formed. 25 is different from the magnetic sensor 68 according to the eighth embodiment in that four magneto-sensitive 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 elements are denoted by the same reference numerals, and overlapping descriptions are omitted.

In the present embodiment, the magnetic flux collecting member 30 is erected and mounted 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 so 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. As a result, as in the magnetic sensor 71 according to the eleventh embodiment, even if 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 canceled correctly, but also , it becomes possible to prevent the magnetic saturation of the magnetic flux collecting member 30 .

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

As shown in FIGS. 28 and 29, in the magnetic sensor 73 according to the thirteenth embodiment, the compensating coil C is wound around the third portion 33 of the magnetic flux collecting member 30, and the element formation surface of the sensor chip 20 is formed. 25 is different from the magnetic sensor 70 according to the tenth embodiment in that four magneto-sensitive elements R1 to R4 are formed. Other basic configurations are the same as those of the magnetic sensor 70 according to the tenth embodiment.

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

Although the preferred embodiments of the present invention have been described above, the present invention is not limited to the above-described embodiments, and various modifications can be made without departing from the gist of the present invention. Needless to say, it is included within the scope.

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 forming surface 26 rear surface 30, 30A, 30B magnetic collecting member 30M magnetic part 30N, 30N ₁ , 30N ₂ non-magnetic portion 31 first portion 32 second portion 33 third portions 31a, 32a base portions 31b, 32b tip portion 40 bill sensor 41 detection heads 81 to 86 terminal electrode 91 differential amplifier 92 detection circuit 51 ~ 53 Magnetic layer C Compensating coils R1 ~ R4 Magneto-sensitive 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 coming into contact with the element forming surface of the sensor chip, and when viewed from a direction perpendicular to the main surface of the circuit board, the A magnetic sensor, comprising: first and second portions located on opposite sides of a sensor chip; and a third portion connecting said first portion and said 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;
2. The magnetic sensor according to claim 1, wherein said first and second portions of said magnetic flux collecting member respectively cover said first and second side surfaces of said sensor chip. the sensor chip further has a third side perpendicular to the main surface of the circuit board and perpendicular to the first and second sides;
3. 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 parallel to the first and second side surfaces of the sensor chip more than its length in a direction perpendicular to the first and second side surfaces of the sensor chip. 4. The magnetic sensor of claim 3, wherein the length in the direction is longer. The third portion of the magnetic flux collecting member has a length perpendicular to the first and second side surfaces of the sensor chip that is longer than a length in a direction parallel to the first and second side surfaces of the sensor chip. 4. The magnetic sensor of claim 3, wherein the length in the direction is longer. 6. The magnetic sensor according to any one of claims 3 to 5, wherein the magnetic flux collecting member is made of a single magnetic material. 7. The method according to claim 6, wherein the thickness of the magnetic flux collecting member with respect to the main surface of the circuit board is greater than the thickness of the sensor chip with respect to the main surface of the circuit board. magnetic sensor. 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 is positioned 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 positioned between the height of the lower surface of the magnetic part and the height of the upper surface with respect to the main surface of the circuit board. 6. A magnetic sensor as claimed in any one of claims 3 to 5. 8. The magnetic sensor according to claim 1, wherein the sensor chip is mounted so that the element forming surface faces the main surface of the circuit board. 10. The method according to claim 9, wherein the thickness of the magnetic flux collecting member with respect to the main surface of the circuit board is thinner than the thickness of the sensor chip with respect to the main surface of the circuit board. magnetic sensor. 2. 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 respectively cover the first and second side surfaces of the sensor chip;
12. The magnetic sensor according to claim 11, wherein the gap between the first and second portions of the magnetic flux collecting member has a stepped shape that narrows 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 portion made of a magnetic material and first and second nonmagnetic portions made of a nonmagnetic material,
12. 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,
12. The magnetic sensor according to claim 11, wherein the sensor chip is mounted so that the element forming surface faces the main surface of the circuit board. 15. The magnetic sensor according to any one of claims 1 to 14, wherein a magnetic layer adjacent to the magneto-sensitive element is provided on the element forming surface of the sensor chip. 16. The magnetic sensor of any preceding claim, further comprising a compensating coil wound around the third portion of the magnetic collecting member.

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