TWI679401B - Magnetic sensor and motor - Google Patents

Abstract

The invention provides a magnetic sensor having a magnetoresistive effect element. When the magnetic sensor is used to sense a situation where a magnet is fixed to a shaft end of a rotating shaft, the axial direction of the rotating shaft can be reduced. When observing, the offset between the center of the magnet and the center of the magnetic induction area of the magnetoresistive effect element is sensed. The magnetic sensor 11 includes: a magnetoresistance effect element; an element substrate 24 on which a magnetoresistance effect element is formed; a box-shaped package body 25 that accommodates the element substrate 24; and a transparent sealing member 26 that is to be formed on a package The opening of the body body 25 is closed; a position alignment mark M1 is formed on the element substrate 24, and the mark M1 is used to position the magnetoresistive effect element with respect to the mounting member 14 on which the magnetic sensor 11 is mounted.

Description

Magnetic sensor and motor

The invention relates to a magnetic sensor with a magnetoresistive effect element. The present invention also relates to a motor having the magnetic sensor.

A motor with an encoder is currently known (for example, refer to Patent Document 1). In the motor described in Patent Document 1, the encoder includes: a sensing magnet fixed to a shaft end of a rotating shaft; a magnetic sensor arranged opposite the sensing magnet; and a sensor substrate for assembling the magnetic sensor And a substrate holder that holds the sensor substrate. The substrate holder is fixed to the motor case. The magnetic sensor has a magnetoresistive effect element. In addition, as the magnetic sensor, a magnetic sensor having a magnetoresistive effect element and an element substrate on which the magnetoresistive effect element is formed is known (for example, refer to Patent Document 2).

Prior art literature Patent literature

Patent Document 1: Japanese Patent Laid-Open No. 2012-168016

Patent Document 2: International Publication No. 2014/155886

In the motor described in Patent Document 1, if the offset between the center of the sensing magnet and the center of the magnetic induction region of the magnetoresistive effect element is large when viewed from the axial direction of the rotating shaft, the detection accuracy of the encoder is reduced. Therefore, it is preferable that, in the motor, the offset between the center of the sensing magnet and the center of the magnetic induction region of the magnetoresistive effect element is small when viewed from the axial direction of the rotation shaft.

Therefore, an object of the present invention is to provide a magnetic sensor having a magnetoresistive effect element, which can reduce spin when the magnetic sensor is applied to a motor in which a magnet is fixed to a shaft end of a rotating shaft When the shaft is viewed in the axial direction, the offset between the center of the magnet and the center of the magnetic induction region of the magnetoresistive effect element is sensed. Another object of the present invention is to provide a motor having the magnetic sensor.

In order to solve the above-mentioned problems, the magnetic sensor of the present invention has a magnetoresistive effect element, which is characterized in that it has: an element substrate formed with a magnetoresistive effect element; and a box-shaped package body which houses An element substrate; and a transparent sealing member that seals the element substrate by closing an opening formed in the package body; a position alignment mark is formed on the element substrate, and the mark is used to make the magnetoresistive effect element relative to the mounting Position the mounting parts with magnetic sensors.

In the magnetic sensor of the present invention, a position alignment mark is formed on the element substrate on which the magnetoresistive effect element is formed, and the mark is used to position the magnetoresistive effect element with respect to the mounting member on which the magnetic sensor is mounted. quasi. In the present invention, the sealing member that seals the element substrate is transparent. Therefore, in the present invention, when the magnetic sensor is mounted on the mounting member, it is possible to position the magnetoresistive effect element with respect to the mounting member while confirming the positioning alignment mark. Therefore, in the present invention, the magnetoresistive effect element can be accurately mounted on the mounting member. As a result, in the present invention, when the magnetic sensor is applied to a motor in which the magnet is fixed to the shaft end of the rotating shaft, if the mounting member is accurately mounted on the rotating shaft, the self-rotating shaft can be reduced. When viewed in the axial direction, the offset between the center of the magnet and the center of the magnetic induction area of the magnetoresistive effect element is sensed.

In the present invention, the sealing member is preferably a transparent glass cover fixed to the package body so as to close the opening of the package body. With such a configuration, it is possible to suppress a reduction in the detection accuracy of the magnetoresistive effect element compared to a case where the sealing member is a resin filled with a package body so as to close the opening. That is, the detection of the magnetoresistive effect element The accuracy may decrease due to the influence of the stress acting on the magnetoresistive effect element and the influence of humidity. However, when the sealing member is a resin filled in the package body, the detection accuracy of the magnetoresistive effect element may be affected by the resin. A problem that the influence of the stress acting on the magnetoresistive effect element and the influence of moisture absorption by the resin are reduced. In view of this, if the sealing member is a transparent glass cover that is fixed to the package body so as to close the opening, such a problem does not occur. Therefore, it is possible to suppress a decrease in the detection accuracy of the magnetoresistive effect element. In addition, if the sealing member is a transparent glass cover that is fixed to the package body so as to close the opening, for example, when the cover is subsequently fixed to the package body, it can be confirmed whether the cover is firmly adhered to the package body and then fixed. Ontology. Therefore, the element substrate can be reliably sealed by the cover.

In the present invention, it is preferable that when viewed from the thickness direction of the element substrate, the marks are formed at two locations on the first imaginary line passing through the center of the magnetic induction region of the magnetoresistive effect element and the first imaginary line passing through the center of the magnetic induction region. A total of four parts of the two parts on the second imaginary line with different lines. With this configuration, the center of the magnetic induction region can be detected based on the marks formed at the four locations. In addition, with such a configuration, compared with a case where a mark is formed at one portion in the center of the magnetic induction region, the mark can be formed on a portion of the element substrate where the mark is easily formed. Therefore, a mark can be easily formed on an element substrate. In addition, with this configuration, when the magnetic sensor is mounted on the mounting member, the rotation direction of the magnetic sensor about the center of the magnetic induction region when viewed from the thickness direction of the element substrate can be adjusted.

In the present invention, when viewed from the thickness direction of the element substrate, the mark may also be formed at the center of the magnetic induction region of the magnetoresistive effect element. In this case, it is possible to set the formation portion of the mark to a minimum.

The magnetic sensor of the present invention can be applied to a motor having: a rotor having a rotating shaft; a stator; a motor housing containing the stator; a sensing magnet fixed to a shaft end of the rotating shaft; , Which is equipped with a magnetic sensor; and as a mounting part A substrate holder for fixing a sensor substrate and fixing the sensor substrate to a motor housing. In this case, the magnetic sensor is arranged so as to face the sensing magnet so that the axial direction of the rotating shaft is consistent with the thickness direction of the element substrate. In this motor, when a sensor substrate on which a magnetic sensor is mounted is mounted on a substrate holder, it is possible to position the magnetoresistive effect element with respect to the substrate holder while confirming the position alignment mark. Therefore, the magnetoresistive effect element can be accurately mounted on the substrate holder. As a result, by accurately mounting the substrate holder on the motor case, it is possible to reduce the offset between the center of the sensing magnet and the center of the magnetic induction film of the magnetoresistive effect element when viewed from the axial direction of the rotating shaft.

In the present invention, it is preferable that, when viewed from the axial direction, a circular reference serving as a reference for positioning the substrate holder in the radial direction with respect to the motor housing is formed on the outer peripheral side in the radial direction of the rotation axis of the substrate holder. A plane or a plurality of arc-shaped reference planes, when viewed from the axial direction, the center of curvature of the reference plane is consistent with the center of the magnetic induction region. With this configuration, the magnetoresistive element can be accurately mounted on the motor case in the radial direction of the rotation shaft. Therefore, it is possible to effectively reduce the offset between the center of the sensing magnet and the center of the magnetic induction region of the magnetoresistive effect element when viewed from the axial direction of the rotation axis.

In the present invention, it is preferable that a plurality of pins protruding toward the sensor substrate in the axial direction are formed on the substrate holder, a through hole through which the pin is inserted is formed on the sensor substrate, and the outer peripheral surface of the pin communicates with the through hole. A gap is formed between the inner peripheral surfaces of the holes for adjusting the position of the magnetoresistive effect element relative to the substrate holder. With this configuration, when the sensor substrate with the magnetic sensor mounted is mounted on the substrate holder, the sensor substrate can be adjusted relative to the substrate holder in a state where the pin has been inserted into the through hole. Its installation position. Therefore, when the sensor substrate is mounted on the substrate holder while the mounting position of the sensor substrate with respect to the substrate holder is adjusted, the sensor substrate does not deviate greatly from the substrate holder. As a result, the mounting operation for mounting the sensor substrate on the substrate holder can be easily performed.

In the present invention, it is preferred that the pin protrude from one surface of the front end side of the sensor substrate. The adhesive agent is inserted into the through hole in a manner as described above, and the adhesive is applied so as to cover the front end side of the pin protruding from the sensor substrate and one surface of the sensor substrate. With such a configuration, since the bonding operation can be performed while confirming the applied adhesive, the bonding operation can be performed more easily than, for example, a case where the adhesive flows between the other surface of the sensor substrate and the substrate holder. . In addition, with this configuration, the sensor substrate and the substrate holder can be temporarily fixed by an adhesive after the magnetoresistive effect element is aligned with respect to the substrate holder while the alignment mark is confirmed.

As described above, in the magnetic sensor of the present invention, when applied to a motor in which the sensing magnet is fixed to the shaft end of the rotating shaft, the center of the sensing magnet can be reduced when viewed from the axial direction of the rotating shaft. Offset from the center of the magnetic induction film of the magnetoresistive effect element. In addition, in the motor of the present invention, it is possible to reduce the amount of offset between the center of the sensing magnet and the center of the magnetic induction film of the magnetoresistive effect element when viewed from the axial direction of the rotating shaft.

1‧‧‧ Motor

2‧‧‧rotation axis

3‧‧‧Motor housing

4‧‧‧testing agency

6‧‧‧shell body

7, 8‧‧‧ cover parts

8a‧‧‧through hole

8b‧‧‧ datum

10‧‧‧ sensing magnet

10a‧‧‧magnet

11‧‧‧ Magnetic Sensor

12‧‧‧shell

13‧‧‧ sensor substrate

13a‧‧‧Slit

13b‧‧‧through hole

13c‧‧‧Notch

14‧‧‧ substrate holder (mounting parts)

14a‧‧‧ tube

14b‧‧‧ protrusion

14c, 14d‧‧‧ convex

14e‧‧‧pin

14f‧‧‧step surface

14g‧‧‧through hole

14h‧‧‧outer surface (reference surface)

15‧‧‧ connector

18, 20‧‧‧ screws

19‧‧‧ Adhesive

23‧‧‧MR element (magnetoresistive effect element)

24‧‧‧Element substrate

25‧‧‧package body

26‧‧‧Glass cover (sealing member, cover)

29‧‧‧Resistance film for temperature monitoring

30‧‧‧Heating resistance film

31, 32‧‧‧A phase (SIN) magnetic induction film

33, 34‧‧‧B-phase (COS) magnetic induction film

36‧‧‧ Magnetic induction area

-A, + A, -B, + B‧‧‧ output terminals

C1‧‧‧Curvature Center of Curvature (Curvature Center of Reference Surface)

C2‧‧‧ Center of Magnetic Induction Area

GNDA, GNDB‧‧‧ ground terminal

L1, L11‧‧‧The first imaginary line

L2, L12‧‧‧Second imaginary line

M1, M11‧‧‧ mark

VccA, VccB, VccH, VccS‧‧‧ Power terminals

FIG. 1 (A) is a perspective view of a motor according to an embodiment of the present invention, and FIG. 1 (B) is a perspective view of a state where a casing is removed from the motor shown in FIG.

FIG. 2 is a perspective view of the cover member shown in FIG. 1. FIG.

FIG. 3 is a perspective view of a sensing magnet and a magnetic sensor fixed to the opposite ends of the output of the rotating shaft shown in FIG. 1 (B).

FIG. 4 is a perspective view of the detection mechanism shown in FIG. 1.

FIG. 5 is an exploded perspective view of the detection mechanism shown in FIG. 4.

FIG. 6 is a plan view showing the magnetic sensor and the sensor substrate shown in FIG. 1 from the output side.

FIG. 7 is a plan view showing the substrate holder shown in FIG. 1 from the output side.

FIG. 8 is a cross-sectional view of a bonding portion between the sensor substrate and the pin shown in FIG. 4.

FIG. 9 is a perspective view showing the magnetic sensor shown in FIG. 3 from the output side.

FIG. 10 is a plan view of an element substrate housed in the package body shown in FIG. 9.

FIG. 11 is a diagram for explaining a mounting method when the sensor substrate shown in FIG. 5 is mounted on a substrate holder.

Hereinafter, embodiments of the present invention will be described with reference to the drawings.

(Overall composition of the motor)

FIG. 1 (A) is a perspective view of a motor 1 according to an embodiment of the present invention, and FIG. 1 (B) is a perspective view of a state where the casing 12 is removed from the motor 1 shown in FIG. 1 (A). FIG. 2 is a perspective view of the cover member 8 shown in FIG. 1. FIG. 3 is a perspective view of the sensing magnet 10 and the magnetic sensor 11 fixed to the opposite ends of the output of the rotating shaft 2 shown in FIG. 1 (B).

The motor 1 of this embodiment is an inner rotor type motor. The motor 1 includes a stator (not shown) formed in a substantially cylindrical shape, a rotor having a rotating shaft 2 and disposed on an inner peripheral side of the stator, and a motor case 3 which houses the stator. One of the stator or the rotor has a driving magnet (not shown), and the other of the stator or the rotor has a driving coil (not shown). In this embodiment, the rotor has a driving magnet, and the stator has a driving coil. The motor 1 includes a detection mechanism 4 for detecting a rotational position of the rotor.

In the following description, the radial direction of the rotating shaft 2 (ie, the radial direction of the rotor) is referred to as “radial direction”, and the circumferential direction of the rotating shaft 2 (ie, the circumferential direction of the rotor) is referred to as “circumferential direction” to rotate The axial direction of the shaft 2 (ie, the axial direction of the rotor) is “axial”. The output side of the rotation axis 2 in the axial direction (the Z1 direction side in FIG. 1 and the like) is the “front” side, and the output side of the rotation axis 2 in the axial direction (the Z2 direction side in FIG. 1 and the like) is the “rear” side. "side.

As shown in FIG. 1, the motor case 3 includes a cylindrical case body 6 that constitutes a side surface of the motor case 3, a cover member 7 that is fixed to the front end of the case body 6, and a cover member 8 that is fixed to the case. The rear end of the body 6. As shown in FIG. 2, a through hole 8 a is formed in the center of the cover member 8 in the radial direction and penetrates in the axial direction. The through hole 8a is formed in a circular hole shape with a step difference. The inner peripheral surface of the rear end portion of the through hole 8a becomes the reference surface 8b, and the reference surface 8b is used to align in the radial direction. The substrate holder 14 described later that constitutes the detection mechanism 4 performs positioning. The reference surface 8b is formed in a cylindrical surface shape. That is, the shape of the reference surface 8b is circular when viewed from the axial direction. A bearing (not shown) that rotatably supports the rotation shaft 2 is attached to the front end portion of the through hole 8a. When viewed from the axial direction, the center of the reference surface 8b coincides with the center of the rotation shaft 2. In addition, in FIG. 1, illustration of the through-hole 8a is omitted.

The detection mechanism 4 is a magnetic rotary encoder. As shown in FIG. 3, the detection mechanism 4 includes: a sensing magnet 10; and a magnetic sensor 11 which is disposed to face the sensing magnet 10. The detection mechanism 4 is disposed on the rear side of the rotor and the stator. As shown in FIG. 1 (A), the detection mechanism 4 is covered by a casing 12 fixed to a cover member 8. The magnetic sensor 11 is mounted on a sensor substrate 13. The sensor substrate 13 is fixed to a substrate holder 14. The substrate holder 14 is fixed to the cover member 8. The substrate holder 14 in this embodiment is a mounting member for mounting the magnetic sensor 11. The magnetic sensor 11 is mounted on the substrate holder 14 via the sensor substrate 13. The specific structures of the magnetic sensor 11, the sensor substrate 13, and the substrate holder 14 will be described later.

The sensing magnet 10 is a permanent magnet formed in a disc shape. The sensing magnet 10 is fixed to the shaft end of the rotating shaft 2 (specifically, the rear end of the rotating shaft 2) directly or via a specific magnet holder (not shown), and the rear surface of the sensing magnet 10 is separated by a specific gap. It faces the magnetic sensor 11. When viewed from the axial direction, the sensing magnet 10 is fixed to the rotating shaft 2 so that the center of the sensing magnet 10 and the center of the rotating shaft 2 coincide.

The surface of the sensing magnet 10 facing the magnetic sensor 11 (that is, the rear surface of the sensing magnet 10) is magnetized into N and S poles one by one in a circumferential direction. That is, the facing surface of the sensing magnet 10 and the magnetic sensor 11 is magnetized into two poles in the circumferential direction. The sensing magnet 10 of this embodiment is composed of two magnet pieces 10a formed in a semi-circular plate shape. One of the two magnet pieces 10a is magnetized to an N-pole rear surface, and the other magnet piece 10a is rear-surfaced. Magnetized as S pole. In addition, the sensing magnet 10 may be formed of a single magnet piece formed in a disc shape.

(Structure of sensor substrate and substrate holder)

FIG. 4 is a perspective view of the detection mechanism 4 shown in FIG. 1. FIG. 5 is an exploded perspective view of the detection mechanism 4 shown in FIG. 4. FIG. 6 is a plan view showing the magnetic sensor 11 and the sensor substrate 13 shown in FIG. 1 from the output side. FIG. 7 is a plan view showing the substrate holder 14 shown in FIG. 1 from the output side. FIG. 8 is a cross-sectional view of a bonding portion between the sensor substrate 13 and the pin 14e shown in FIG. 4.

The sensor substrate 13 is a printed wiring board formed in a flat plate shape. The sensor substrate 13 is arranged such that the thickness direction of the sensor substrate 13 is aligned with the axial direction. The magnetic sensor 11 is mounted at the center of the front surface of the sensor substrate 13. Two slits 13 a are formed in the sensor substrate 13 so as to surround the magnetic sensor 11. Further, the sensor substrate 13 is formed with a through hole 13 b penetrating in the axial direction (that is, the thickness direction of the sensor substrate 13) and a notch portion cut from the outer peripheral end of the OR substrate 13 to the center side. 13c.

The slit 13 a is formed so as to penetrate the sensor substrate 13 in the axial direction, and is formed in a substantially L shape. The through hole 13 b is formed in a circular hole shape and is formed near the outer peripheral end of the sensor substrate 13. In addition, the through holes 13b are formed at three locations. The three through-holes 13b are formed at positions separated from each other so as to form a substantially right-angled triangle from an imaginary line connected by the three through-holes 13b when viewed from the axial direction. The cutout portion 13c is formed in a U shape. The notch portion 13 c is formed at two locations so as to sandwich the magnetic sensor 13. In addition, a connector 15 is mounted on the rear surface of the sensor substrate 13.

The substrate holder 14 is formed of a resin material. The substrate holder 14 includes a cylindrical portion 14a formed in a cylindrical shape, and three protruding portions 14b protruding radially outward from the front end side of the outer peripheral surface of the cylindrical portion 14a. The inner peripheral surface of the cylindrical portion 14a has a cylindrical surface. That is, when viewed from the axial direction, the inner peripheral surface of the cylindrical portion 14a is circular. The rear end surface of the cylindrical portion 14a is formed in a flat shape orthogonal to the axial direction. The sensor substrate 13 is fixed to the rear end side of the cylindrical portion 14a.

Formed on the end face behind the cylindrical portion 14a are two cylindrical convex portions 14c protruding rearwardly and one cylindrical convex portion 14d protruding rearwardly. Front ends of the convex portions 14c and 14d The surface is formed in a planar shape orthogonal to the axial direction. The front surface of the sensor substrate 13 is in contact with the front end surfaces of the convex portions 14 c and 14 d. A threaded hole is formed in the inner peripheral surface of the convex portion 14c. A screw 18 for fixing the sensor substrate 13 to the substrate holder 14 is engaged at the threaded hole. The screws 18 are arranged so as to pass through the cutout portions 13 c of the sensor substrate 13.

In addition, three pins 14e are formed on the end surface behind the cylindrical portion 14a, and the pins 14e project toward the sensor substrate 13 in the axial direction (that is, project toward the rear side). The pin 14e is formed in a cylindrical shape with a step, and the pin 14e is formed with a circular stepped surface 14f orthogonal to the axial direction. The three pins 14e are respectively inserted into the three through holes 13b of the sensor substrate 13. Specifically, the front surface of the sensor substrate 13 is in contact with the step surface 14f, and the front end side of the pin 14e is inserted into the through hole 13b. In addition, the front end side of the pin 14 e protrudes further to the rear side than the rear surface of the sensor substrate 13.

As shown in FIG. 8, a gap is formed between the outer peripheral surface of the front end side of the pin 14e inserted into the through hole 13b and the inner peripheral surface of the through hole 13b. Specifically, in a direction orthogonal to the axial direction, a gap for adjusting the fixed position of the sensor substrate 13 with respect to the substrate holder 14 is formed within the outer peripheral surface of the front end side of the pin 14e and the through hole 13b. Between the sides. More specifically, a gap for adjusting a position of a magnetoresistance effect element 23 described later on the magnetic sensor 11 mounted on the sensor substrate 13 in a direction orthogonal to the axial direction is formed at the front end of the pin 14e. Between the lateral outer peripheral surface and the inner peripheral surface of the through hole 13b.

In this embodiment, the sensor substrate 13 is temporarily fixed to the substrate holder 14 with an adhesive 19 before being fixed to the substrate holder 14 with screws 18. As shown in FIG. 8, the adhesive 19 is applied so as to spread over the front end side of the pin 14 e protruding further to the rear side than the rear surface of the sensor substrate 13 and the rear surface of the sensor substrate 13. The adhesive 19 is, for example, an ultraviolet (UV) curing type adhesive.

When viewed from the axial direction, the three protruding portions 14b are arranged at a pitch of approximately 120 degrees with respect to the center of the inner peripheral surface of the cylindrical portion 14a. A through hole 14g is formed in the protruding portion 14b, and the through hole 14g is provided with a screw 20 (see FIG. 4) for fixing the substrate holder 14 to the cover member 8. Insert. In addition, the cover member 8 is formed with screw holes of the engaging screws 20. However, the illustration of the screw holes is omitted in FIG. 2.

The shape of the projecting portion 14b when viewed from the axial direction of the outer peripheral surface 14h is formed into a curved shape having an arc shape. As shown in FIG. 7, when viewed from the axial direction, the curvature centers C1 of the outer peripheral surfaces 14h of the three protruding portions 14b are consistent. In this embodiment, the outer peripheral surface 14h of the protruding portion 14b serves as a reference plane for positioning the substrate holder 14 with respect to the cover member 8 in the radial direction. When the substrate holder 14 is fixed to the cover member 8, a cover member is used. The reference surface 8b of 8 and the outer peripheral surface 14h of the protruding portion 14b determine the position of the substrate holder 14 with respect to the cover member 8 in the radial direction. That is, in this embodiment, when viewed from the axial direction, a plurality of arcs are formed on the outer peripheral side in the radial direction of the substrate holder 14 to serve as a positioning reference for the substrate holder 14 in the radial direction with respect to the motor case 3 Base surface.

In a state where the substrate holder 14 is fixed to the cover member 8, when viewed from the axial direction, the center of curvature C1 of the outer peripheral surface 14h of the three protruding portions 14b coincides with the center of the reference surface 8b. As described above, the center of the reference surface 8b coincides with the center of the rotating shaft 2 when viewed from the axial direction. Therefore, when viewed from the axial direction, the center of curvature C1 of the outer peripheral surface 14h of the three protruding portions 14b and the center of the rotation shaft 2 Centered. When viewed from the axial direction, the center of curvature C1 of the outer peripheral surface 14h of the three protruding portions 14b coincides with the center of the inner peripheral surface of the cylindrical portion 14a.

(Composition of magnetic sensor)

FIG. 9 is a perspective view showing the magnetic sensor 11 shown in FIG. 3 from the output side. FIG. 10 is a plan view of the element substrate 24 housed in the package body 25 shown in FIG. 9.

The magnetic sensor 11 includes: a magnetoresistive effect element 23 (hereinafter referred to as "MR element 23"); an element substrate 24 on which the MR element 23 is formed; a box-shaped package body 25 that accommodates the element substrate 24; and a seal. The component 26 seals the element substrate 24 (ie, seals the MR element 23) by closing the opening of the package body 25. The package body 25 is formed in a rectangular parallelepiped box shape with an open end. The sealing member 26 of this embodiment is a transparent glass cover (glass cover). Therefore, the sealing member 26 is hereinafter referred to as "glass cover 26".

The glass cover 26 is formed in a substantially rectangular flat plate shape. The glass cover 26 is fixed to the front end of the package body 25 so as to close the opening of the package body 25. In addition, the glass cover 26 is fixed to the front end of the package body 25 by the following, and the package body 25 and the glass cover 26 form a sealed space for accommodating the element substrate 24. A gap is formed between the element substrate 24 and the glass cover 26 accommodated in the package body 25, and the element substrate 24 and the glass cover 26 are not in contact. Since the glass cover 26 is transparent, when the magnetic sensor 11 is viewed from the front surface side, the front surface of the element substrate 24 accommodated in the package body 25 can be seen.

The element substrate 24 is a printed circuit board having a rectangular flat plate shape. The element substrate 24 is arranged so that the thickness direction of the element substrate 24 is aligned with the axial direction. The element substrate 24 is formed with not only the MR element 23 but also a temperature monitoring resistance film 29 and a heating resistance film 30. The MR element 23, the temperature monitoring resistance film 29, and the heating resistance film 30 are formed on the front surface of the element substrate 24. The MR element 23, the temperature monitoring resistance film 29, and the heating resistance film 30 are covered with an insulating film.

The MR element 23 includes A-phase (SIN) magnetic induction films 31 and 32 and B-phase (COS) magnetic induction films 33 and 34. The magnetic induction films 31 to 34 are formed in the center of the element substrate 24. In this embodiment, as shown in FIG. 10, a circular magnetic induction region 36 is formed by the magnetic induction films 31 to 34. The phase of the A-phase magnetic induction films 31 and 32 and the phase of the B-phase magnetic induction films 33 and 34 differ by 90 degrees. That is, the A-phase magnetic induction films 31 and 32 and the B-phase magnetic induction films 33 and 34 have a phase difference of 90 degrees. Moreover, the phase of the magnetic induction film 31 is 180 degrees out of phase with respect to the phase A, and the phase of the magnetic induction film 33 is 180 degrees out of phase with respect to the B phase.

The magnetic induction films 31 and 32 constitute a bridge circuit, and one end of the bridge circuit is connected to the power terminal VccA, and the other end is connected to the ground terminal GNDA. Further, the midpoint position of the magnetic induction film 31 is connected to the output terminal + A, and the midpoint position of the magnetic induction film 32 is connected to the output terminal -A. Similarly, the magnetic induction films 33 and 34 constitute a bridge circuit, and one end of the bridge circuit is connected to the power terminal VccB and the other end is connected to the ground terminal GNDB. And the magnetic induction film 33 The midpoint position is connected to the output terminal + B, and the midpoint position of the magnetic induction film 34 is connected to the output terminal -B.

The heating resistance film 30 is formed in a rectangular frame shape. In addition, the heating resistance film 30 is formed along the end surface of the element substrate 24 and is arranged so as to surround the magnetic induction region 36. The heating resistance film 30 is connected to the power terminal VccH and is connected to the ground terminal GNDA. The temperature monitoring resistance film 29 is disposed between the magnetic induction region 36 and the heating resistance film 30. The temperature monitoring resistance film 29 is connected to the power terminal VccS and is connected to the ground terminal GNDB. In this embodiment, the temperature control for controlling the power supply to the heating resistance film 30 is performed based on the resistance change of the temperature monitoring resistance film 29.

A mark M1 is formed on the element substrate 24 to position the MR element 23 with respect to the substrate holder 14. Specifically, a mark M1 for positioning the MR element 23 with respect to the substrate holder 14 in a direction orthogonal to the axial direction (radial direction) is formed on the element substrate 24. The mark M1 is formed on the front surface of the element substrate 24. As shown in FIG. 10, when viewed from the thickness direction of the element substrate 24, if an imaginary line passing through the center C2 of the magnetic induction region 36 is taken as an imaginary line L1, an imaginary line passing through the center C2 of the magnetic induction region 36 and different from the imaginary line L1 It is an imaginary line L2. When viewed from the thickness direction of the element substrate 24, the mark M1 is formed at two locations on the imaginary line L1 and four locations in total on the imaginary line L2. In this embodiment, the imaginary lines L1 and L2 are orthogonal to each other and parallel to the end surface of the element substrate 24. Further, the marks M1 formed at two locations on the virtual line L1 are formed so as to sandwich the magnetic induction region 36, and the marks M1 formed at two locations on the virtual line L2 are formed so as to sandwich the magnetic induction region 36. The imaginary line L1 in this embodiment is a first imaginary line, and the imaginary line L2 is a second imaginary line.

(Installation method of sensor substrate to substrate holder)

FIG. 11 is a diagram for explaining a mounting method when the sensor substrate 13 shown in FIG. 5 is mounted on a substrate holder 14.

The sensor substrate 13 in a state where the magnetic sensor 11 is mounted is mounted on the substrate and held. In the case of the rack 14, first, the pins 14e of the substrate holder 14 are inserted into the through holes 13b of the sensor substrate 13 in a state where the magnetic sensor 11 is mounted. Specifically, the pin 14e is inserted into the through hole 13b until the front surface of the sensor substrate 13 comes into contact with the step surface 14f of the pin 14e. After that, the center of curvature C1 of the outer peripheral surface 14h of the three protrusions 14b when viewed in the axial direction is calculated by image processing, and the four induction marks M1 are used to calculate the magnetic induction when viewed in the axial direction through image processing. Center C2 of area 36.

Thereafter, as shown in FIG. 11, when viewed from the axial direction, the center of curvature C1 of the outer peripheral surface 14h and the center C2 of the magnetic induction region 36 are aligned so that the sensor substrate 13 is opposed to the axis orthogonal to the plane. The substrate holder 14 is movable. When viewed from the axial direction, if the curvature center C1 of the outer peripheral surface 14h is consistent with the center C2 of the magnetic induction region 36, the front end side of the pin 14e protruding farther back than the rear surface of the sensor substrate 13 and the sensor substrate The adhesive agent 19 is applied on the rear surface 13 to temporarily fix the sensor substrate 13 to the substrate holder 14. After that, the sensor substrate 13 is fixed to the substrate holder 14 with screws 18.

In this way, since the sensor substrate 13 in the state where the magnetic sensor 11 is mounted is mounted on the substrate holder 14, the sensor substrate 13 in the state where the magnetic sensor 11 is mounted is mounted on the substrate When the holder 14 is viewed from the axial direction, the center of curvature C1 of the outer peripheral surface 14h is consistent with the center C2 of the magnetic induction region 36.

(Main effects of this embodiment)

As described above, in this embodiment, a position alignment mark M1 is formed on the front surface of the element substrate 24 on which the MR element 23 is formed to position the MR element 23 with respect to the substrate holder 14. Furthermore, in this embodiment, the glass cover 26 fixed to the package body 25 in which the element substrate 24 is housed is transparent, and when the magnetic sensor 11 is viewed from the front surface side, the package body 25 can be seen. Element substrate 24 front surface. Therefore, in the present embodiment, as described above, when the sensor substrate 13 equipped with the magnetic sensor 11 is mounted on the substrate holder 14, the mark M1 can be used to view the outer peripheral surface 14h when viewed from the axial direction. In a manner that the center of curvature C1 is consistent with the center C2 of the magnetic induction region 36, The position of the MR element 23 with respect to the substrate holder 14 is adjusted. Therefore, in this embodiment, the MR element 23 can be accurately mounted on the substrate holder 14.

Further, in this embodiment, when the sensing magnet 10 is viewed from the axial direction, the center of curvature C1 of the outer peripheral surface 14h of the protruding portion 14b coincides with the center of the rotation axis 2 and the center of the sensing magnet 10 and the center of the rotation axis 2 The center is fixed to the rotation shaft 2 in a uniform manner. In summary, in this embodiment, it is possible to reduce the amount of offset between the center of the sensing magnet 10 and the center C2 of the magnetic induction region 36 when viewed from the axial direction.

In this embodiment, the opening on the front end side of the package body 25 is closed by the glass cover 26, and a gap is formed between the element substrate 24 and the glass cover 26 housed in the package body 25. Therefore, in this embodiment, it is possible to suppress a decrease in the detection accuracy of the MR element 23 compared to a case where the sealing member of the sealing element substrate 24 is a resin filled in the package body 25. That is, the detection accuracy of the MR element 23 is reduced due to the influence of the stress acting on the MR element 23 and the influence of humidity, but when the sealing member is a resin filled in the package body 25, the resin acts on The influence of the stress of the MR element 23 and the influence of moisture absorbed by the resin may reduce the detection accuracy of the MR element 23. On the other hand, in this embodiment, since a gap is formed between the element substrate 24 and the glass cover 26 accommodated in the package body 25, such a problem does not occur. Therefore, in this embodiment, it is possible to suppress a decrease in the detection accuracy of the MR element 23.

Furthermore, in this embodiment, since the opening on the front end side of the package body 25 is closed by the transparent glass cover 26, the glass cover 26 can be confirmed when the glass cover 26 is subsequently fixed to the package body 25. Whether or not it is firmly attached to the package body 25. Therefore, the element substrate 24 can be reliably sealed by the glass cover 26.

In this embodiment, an adjustment is made between the outer peripheral surface of the front end side of the pin 14e of the substrate holder 14 and the inner peripheral surface of the through hole 13b of the sensor substrate 13 in a direction orthogonal to the axial direction. The gap of the position of the MR element 23. Therefore, in this embodiment, as described above, the sensor substrate 13 in a state where the magnetic sensor 11 is mounted is mounted on the substrate. In the holder 14, the mounting position of the sensor substrate 13 with respect to the substrate holder 14 can be adjusted in a state where the pin 14 e has been inserted into the through hole 13 b. Therefore, in this embodiment, when the sensor substrate 13 is mounted on the substrate holder 14 while the mounting position of the sensor substrate 13 with respect to the substrate holder 14 is adjusted, the sensor substrate 13 is held relative to the substrate. The rack 14 does not cause a large offset. As a result, in this embodiment, the mounting operation of the sensor substrate 13 to the substrate holder 14 can be easily performed.

In this embodiment, the adhesive 19 is applied so as to spread the front end side of the pin 14e protruding further to the rear side than the rear surface of the sensor substrate 13 and the rear surface of the sensor substrate 13. Therefore, in this embodiment, it is possible to perform a bonding operation while confirming the applied adhesive 19. Therefore, for example, the situation between the end surface after the adhesive flows into the cylindrical portion 14 a of the substrate holder 14 and the front surface of the sensor substrate 13, and the end surface after the adhesive flows into the stepped surface 14 f of the substrate holder 14 and the sensor. Compared with the situation between the front surfaces of the substrate 13, the subsequent operation can be easily performed.

(Other embodiments)

The above-mentioned embodiment is an example of a preferred embodiment of the present invention, but it is not limited thereto, and various changes can be made within a range that does not change the gist of the present invention.

In the above embodiment, the imaginary lines L1 and L2 passing through the center C2 of the magnetic induction region 36 are orthogonal to each other and parallel to the end surface of the element substrate 24. In addition, for example, as shown in FIG. 10, the imaginary lines L11 and L12 passing through the center C2 of the magnetic induction region 36 may substantially coincide with the diagonals of the heating resistance film 30 formed in a rectangular frame shape. In this case, marks M11 are formed at the two locations on the imaginary line L11 and the two locations on the imaginary line L12 to align the MR element 23 with respect to the substrate holder 14. In this case, the imaginary line L11 is a first imaginary line, and the imaginary line L12 is a second imaginary line. In addition, a mark for aligning the MR element 23 with respect to the substrate holder 14 may be formed at one site, two sites, or three sites, or may be formed at five or more sites. For example, when viewed from the thickness direction of the element substrate 24, the mark is also It may be formed in a part of the center C2 of the magnetic induction region 36. In this case, it is possible to minimize the formation portion of the mark.

In addition, when the two parts on the imaginary line L1 and the two parts on the imaginary line L2 form a total of four parts, the mark M1 is formed, and the two parts on the imaginary line L11 and the two parts on the imaginary line L12. In the case where the mark M11 is formed in four places in total, the marks M1 and M11 can be formed on the element substrate 24 where the marks can be easily formed compared to the case where the mark is formed in one place in the center C2 of the magnetic induction region 36. . Therefore, the marks M1 and M11 can be easily formed on the element substrate 24.

In the above embodiment, when viewed from the axial direction, a plurality of arc-shaped reference surfaces (outer peripheral surfaces 14h) are formed on the outer peripheral side in the radial direction of the substrate holder 14, and the reference surfaces are opposed to the substrate holder 14. Positioning reference for the motor housing 3 in the radial direction. In addition, for example, when viewed from the axial direction, a circular reference surface may be formed on the outer peripheral side in the radial direction of the substrate holder 14 as a reference for positioning the substrate holder 14 with respect to the motor housing in the radial direction. A plurality of protrusions may be formed on the outer peripheral side of the substrate holder 14 as a reference for positioning the substrate holder 14 with respect to the motor housing 3 in the radial direction. In addition, in the above embodiment, the sealing member 26 is a transparent glass cover (glass cover), but the sealing member 26 may be a transparent resin filled in the package body 25. In the above-described embodiment, the pin 14e is formed in the substrate holder 14 and the sensor substrate 13 is formed with a through hole 13b through which the pin 14e is inserted. However, the pin 14e and the through hole 13b may not be formed. In addition, in the above-mentioned embodiment, the adhesive 19 is an ultraviolet curing adhesive, but the adhesive 19 may also flow between the end surface of the stepped surface 14f flowing into the substrate holder 14 and the front surface of the sensor substrate 13, and Instant adhesive between the end face after flowing into the convex portions 14 c and 14 d of the substrate holder 14 and the front surface of the sensor substrate 13.

Claims (7)

A magnetic sensor having a magnetoresistive effect element, comprising: an element substrate formed with the magnetoresistive effect element; a box-shaped package body containing the element substrate; and a transparent sealing member. It closes the opening formed in the package body to seal the element substrate, and a position alignment mark is formed on the element substrate, and the position alignment mark is used to make the magnetoresistive effect element relative to the mounting position. The mounting parts of the magnetic sensor are aligned; and the sealing member is a transparent glass cover fixed to the package body so as to close the opening; formed between the element substrate and the glass cover. There is a gap, and the mark of the element substrate accommodated in the package body can be seen from the opening. The magnetic sensor according to claim 1, wherein when viewed from the thickness direction of the element substrate, the mark is formed at two locations on the first imaginary line passing through the center of the magnetic induction region of the magnetoresistive effect element and through the magnetic induction A total of four locations in the center of the region and two locations on a second imaginary line different from the first imaginary line. The magnetic sensor according to claim 1, wherein the mark is formed at the center of the magnetic induction region of the magnetoresistive effect element when viewed from the thickness direction of the element substrate. A motor is characterized by: a rotor having a rotating shaft; a stator; a motor housing containing the stator; a sensing magnet fixed to a shaft end of the rotating shaft; and a magnetic sensor such as a request The magnetic sensor of 1 is arranged to face the above-mentioned sensing magnet in such a manner that the axial direction of the rotation axis is consistent with the thickness direction of the element substrate; the sensor substrate is equipped with the above-mentioned magnetic sensor; and as the mounting The component substrate holder is used for fixing the sensor substrate and fixing the sensor substrate to the motor housing. The motor according to claim 4, wherein when viewed from the axial direction, an outer peripheral side of the rotary shaft of the substrate holder in the radial direction is formed with the substrate holder in the radial direction with respect to the motor housing. The circular reference surface of the positioning reference or the arc-shaped reference surfaces, when viewed from the axial direction, the center of curvature of the reference surface coincides with the center of the magnetic induction region of the magnetoresistive effect element. The motor of claim 4 or 5, wherein a plurality of pins protruding in the axial direction toward the sensor substrate are formed in the substrate holder, and a through hole is formed in the sensor substrate through which the pins are inserted. A gap is formed between the outer peripheral surface of the pin and the inner peripheral surface of the through hole for adjusting the position of the magnetoresistive effect element with respect to the substrate holder. The motor according to claim 6, wherein the pin is inserted into the through-hole so that the front end side of the pin protrudes from one surface of the sensor substrate, so as to be distributed throughout the pin protruding from the sensor substrate. An adhesive is applied to the front end side and one surface of the sensor substrate.