阅读说明：本技术 磁传感器装置 (Magnetic sensor device ) 是由 太田尚城 蔡永福 于 2020-03-11 设计创作，主要内容包括：本发明的磁传感器装置具有自旋阀型的磁阻效应元件,并且能够向该磁阻效应元件的自由层稳定地施加偏置磁场,其具备：自旋阀型的磁阻效应元件；基板,其配置有磁阻效应元件；电源,其供给施加于磁阻效应元件的实质上恒定的电流；以及磁场产生部,其被设置成串联连接于施加于磁阻效应元件的电流的电流路径,并且能够向至少一部分的磁阻效应元件施加偏置磁场,磁场产生部位于一部分的磁阻效应元件的附近,并且位于与基板不同的层。(A magnetic sensor device according to the present invention includes a spin-valve type magnetoresistance effect element, and is capable of stably applying a bias magnetic field to a free layer of the magnetoresistance effect element, and includes: a magnetoresistive effect element of a spin valve type; a substrate provided with a magnetoresistance effect element; a power supply that supplies a substantially constant current applied to the magnetoresistance effect element; and a magnetic field generating unit that is provided in series with a current path of a current applied to the magnetoresistance effect element and is capable of applying a bias magnetic field to at least a part of the magnetoresistance effect element, wherein the magnetic field generating unit is located in the vicinity of the part of the magnetoresistance effect element and in a layer different from the substrate.)

1. A magnetic sensor device, characterized in that,

the disclosed device is provided with:

a magnetoresistive effect element of a spin valve type;

a substrate provided with the magnetoresistance effect element;

a power supply that supplies a substantially constant current applied to the magnetoresistance effect element; and

a magnetic field generating section provided in series to a current path of the current applied to the magnetoresistance effect element and capable of applying a bias magnetic field to at least a part of the magnetoresistance effect element,

the magnetic field generation section is located in the vicinity of the partial magnetoresistance effect element and in a layer different from the substrate.

2. The magnetic sensor device according to claim 1,

the magnetoresistance effect element is configured in a zigzag manner to include: a plurality of elongated portions having a first end and a second end and arranged in a predetermined direction; and a folded portion connected between the first end portions or the second end portions of two of the elongated portions adjacent in the arrangement direction of the elongated portions,

the magnetic field generating portion is located in the vicinity of the turning portion.

3. The magnetic sensor device according to claim 2,

the magnetoresistive effect element is configured in a zigzag manner such that a plurality of the folded portions connected between the first ends or between the second ends of the elongated portions are arranged in a predetermined direction,

the magnetic field generating portion is located in the vicinity of the turning portion.

4. The magnetic sensor device according to claim 3,

the magnetic field generating section is located in the vicinity of the plurality of folded sections so as to be along the arrangement direction of the plurality of folded sections.

5. The magnetic sensor device according to any one of claims 2 to 4,

the magnetoresistance effect element has: a plurality of magnetoresistive effect stacks arranged in a plurality of rows and columns in an array; and a plurality of lead electrodes connected in series in a zigzag manner to the plurality of magnetoresistive effect laminated bodies,

the lead electrode includes: a first lead electrode which connects in series a plurality of the magnetoresistive effect stacks arranged in a first direction; and a second lead electrode connecting the magnetoresistance effect stack at both ends in the first direction in a second direction orthogonal to the first direction,

the elongated portion is composed of the plurality of magnetoresistive effect stacks and the first lead electrode arranged in the first direction,

the folded portion is composed of the magnetoresistance effect stack and the second lead electrode located at both ends in the first direction.

6. The magnetic sensor device according to claim 5,

the second lead electrode has a substantially U-shape in plan view.

7. The magnetic sensor device according to any one of claims 1 to 4,

the magnetic field generating unit is positioned above the magnetoresistance effect element disposed on the substrate with a predetermined distance therebetween.

8. The magnetic sensor device according to any one of claims 1 to 4,

further provided with: a sealing part that integrally seals at least the magnetoresistance effect element and the magnetic field generation part with resin,

the magnetic field generating unit is located in a layer different from the substrate by interposing the resin between the magnetic field generating unit and the magnetoresistance effect element.

9. The magnetic sensor device according to any one of claims 1 to 4,

the magnetoresistance effect element is a TMR element or a GMR element.

Technical Field

The present invention relates to a magnetic sensor device.

Background

In recent years, in various applications, a physical quantity detection device (position detection device) for detecting a physical quantity (for example, a position or a movement amount (change amount) due to a rotational movement or a linear movement of a movable body) has been used. As this physical quantity detection device, a device is known which includes a magnetic sensor capable of detecting a change in an external magnetic field, and which is capable of outputting a sensor signal corresponding to the change in the external magnetic field from the magnetic sensor.

The magnetic sensor includes a magnetic sensor element for detecting a magnetic field to be detected, and a spin valve type magnetoresistance effect element (an AMR element, a GMR element, a TMR element, or the like) whose magnetic resistance changes in accordance with a change in an external magnetic field is known as a relevant magnetic sensor element.

A spin valve type magnetoresistive effect element includes at least: a free layer capable of changing a magnetization direction in response to an external magnetic field; a magnetization pinned layer whose magnetization direction is pinned; and a non-magnetic layer interposed between the free layer and the magnetization pinned layer. In the magnetoresistance effect element having such a structure, the resistance value of the magnetoresistance effect element is determined by the angle formed by the magnetization direction of the free layer and the magnetization direction of the magnetization pinned layer. In addition, since the magnetization direction of the free layer changes in accordance with the external magnetic field, and thus the angle that the free layer makes with the magnetization direction of the magnetization fixed layer changes, the resistance value of the magnetoresistance effect element changes. By the change in the resistance value, a sensor signal corresponding to the change in the external magnetic field can be output.

Prior patent literature

Patent document

Patent document 1: japanese Kohyo publication No. 2014-507001

Patent document 2: japanese laid-open patent publication No. 2002-150518

Patent document 3: japanese Kohyo publication No. 2018-517128

Disclosure of Invention

Technical problem to be solved by the invention

In the above-described spin valve type magnetoresistance effect element, fluctuation in magnetization of the free layer occurs in a zero magnetic field (initial state where no external magnetic field is applied), and thus, noise occurs in the output signal of the magnetic sensor. Conventionally, in order to suppress fluctuation of magnetization of a free layer, a hard magnet or the like for applying a bias magnetic field to the free layer is provided in the vicinity of a magnetoresistive element. However, there is a problem that the structure of the magnetic sensor becomes complicated. Further, there is also a problem that the hard magnet (magnetic sensor device including the hard magnet in the vicinity of the magnetoresistance effect element) is exposed to a large external magnetic field, or a physical impact is applied to the hard magnet, so that the magnetization direction of the hard magnet is irreversibly changed, and it is difficult to stably apply a desired bias magnetic field to the free layer. In particular, as the magnetic sensor is miniaturized, the size of the hard magnet has to be miniaturized, but when the size of the hard magnet is reduced, the magnetization direction of the hard magnet becomes easily changed by an external magnetic field or physical impact.

In view of the above-described problems, it is an object of the present invention to provide a magnetic sensor device having a spin-valve type magnetoresistance effect element and capable of stably applying a bias magnetic field to a free layer of the magnetoresistance effect element.

Means for solving the problems

In order to solve the above-described problem, the present invention provides a magnetic sensor device including: a magnetoresistive effect element of a spin valve type; a substrate provided with the magnetoresistance effect element; a power supply that supplies a substantially constant current applied to the magnetoresistance effect element; and a magnetic field generating unit that is provided so as to be connected in series to a current path of the current applied to the magnetoresistance effect element and is capable of applying a bias magnetic field to at least a part of the magnetoresistance effect element, the magnetic field generating unit being located in the vicinity of the part of the magnetoresistance effect element and in a layer different from the substrate.

The magnetoresistance effect element is configured in a zigzag manner to include: a plurality of elongated portions having a first end and a second end and arranged in a predetermined direction; and a folded portion connected between the first ends or the second ends of two of the elongated portions adjacent in an arrangement direction of the elongated portions, the magnetic field generating portion may be located in a vicinity of the folded portion, the magnetoresistance effect element may be configured to be folded in a zigzag manner so that a plurality of folded portions connected between the first ends or the second ends of the elongated portions are arranged in a predetermined direction, the magnetic field generating portion may be located in a vicinity of the folded portion, and the magnetic field generating portion is preferably located in a vicinity of the plurality of folded portions so as to be along the arrangement direction of the plurality of folded portions.

The magnetoresistance effect element may have: a plurality of magnetoresistive effect stacks arranged in a plurality of rows and columns in an array; and a plurality of lead electrodes connected in series in a zigzag manner to the plurality of magnetoresistive effect laminated bodies, the lead electrodes may include: a first lead electrode which connects in series a plurality of magnetoresistive effect stacks arranged in a first direction; and a second lead electrode that connects the plurality of magnetoresistance effect stacks located at both ends in the first direction in a second direction orthogonal to the first direction, wherein the elongated portion may be formed of the plurality of magnetoresistance effect stacks and the first lead electrode arranged in the first direction, the folded portion may be formed of the magnetoresistance effect stacks located at both ends in the first direction and the second lead electrode, and a shape of the second lead electrode in a plan view may be substantially U-shaped.

The magnetic field generating unit may be positioned above the magnetoresistance effect element disposed on the substrate at a predetermined interval, and may further include: and a sealing portion that integrally seals at least the magnetoresistance effect element and the magnetic field generating portion with a resin, wherein the magnetic field generating portion may be located in a layer different from the substrate by interposing the resin between the magnetic field generating portion and the magnetoresistance effect element.

As the magnetoresistance effect element, a TMR element or a GMR element may be used.

ADVANTAGEOUS EFFECTS OF INVENTION

According to the present invention, it is possible to provide a magnetic sensor device which has a spin-valve type magnetoresistance effect element and can stably apply a bias magnetic field to a free layer of the magnetoresistance effect element.

Drawings

Fig. 1 is a perspective view showing a schematic configuration of one embodiment of a magnetic sensor device according to one embodiment of the present invention.

Fig. 2 is a plan view schematically showing a configuration of one embodiment of a magnetic sensor device according to one embodiment of the present invention.

Fig. 3 is a perspective view showing a schematic configuration of another embodiment (1) of the magnetic sensor device according to the embodiment of the present invention.

Fig. 4 is a plan view schematically showing a configuration of another embodiment (1) of the magnetic sensor device according to the embodiment of the present invention.

Fig. 5 is a perspective view showing a schematic configuration of another embodiment (2) of the magnetic sensor device according to the embodiment of the present invention.

Fig. 6 is a plan view schematically showing the configuration of another embodiment (2) of the magnetic sensor device according to the embodiment of the present invention.

Fig. 7 is a block diagram showing a schematic configuration of a magnetic sensor device according to an embodiment of the present invention.

Fig. 8 is a circuit diagram showing a schematic configuration of one embodiment of a circuit configuration included in a magnetic sensor device according to an embodiment of the present invention.

Fig. 9 is a cross-sectional view showing a schematic structure of a magnetoresistive effect element according to an embodiment of the present invention.

Fig. 10 is a plan view schematically showing the configuration of another embodiment (3) of the magnetic sensor device according to the embodiment of the present invention.

Description of the symbols

1 … … magnetic sensor device

2 … … baseplate

21 … … first side

22 … … second side

3 … … magnetoresistance effect element

31 … … Long strip part

32 … … turn-back part

321 … … first folded part

322 … … second fold back portion

3A … … first magnetoresistance effect element

3B … … second magnetoresistance effect element

4 … … bias magnetic field generating part (Bonding wire)

Detailed Description

Embodiments of the present invention will be described with reference to the accompanying drawings.

Fig. 1 is a perspective view showing a schematic configuration of one embodiment of a magnetic sensor device according to the present embodiment, fig. 2 is a plan view showing a schematic configuration of one embodiment of a magnetic sensor device according to the present embodiment, fig. 3 is a perspective view showing a schematic configuration of another embodiment of a magnetic sensor device according to the present embodiment, fig. 4 is a plan view showing a schematic configuration of another embodiment of a magnetic sensor device according to the present embodiment, fig. 5 is a perspective view showing a schematic configuration of another embodiment of a magnetic sensor device according to the present embodiment, fig. 6 is a plan view showing a schematic configuration of another embodiment of a magnetic sensor device according to the present embodiment, fig. 7 is a block diagram showing a schematic configuration of a magnetic sensor device according to the present embodiment, fig. 8 is a circuit diagram showing a schematic configuration of one embodiment of a circuit configuration included in a magnetic sensor device according to the present embodiment, fig. 9 is a cross-sectional view showing a schematic structure of the magnetoresistive effect element in this embodiment.

Note that in the magnetic sensor according to the present embodiment, "the X-axis direction, the Y-axis direction, and the Z-axis direction" are defined in some drawings as necessary. Here, the X-axis direction and the Y-axis direction are directions substantially orthogonal to each other in a plane parallel to the first surface and the second surface of the substrate in the present embodiment, and the Z-axis direction is a thickness direction of the substrate (a direction orthogonal to the first surface and the second surface of the substrate).

The magnetic sensor device 1 according to the present embodiment includes: a substrate 2 having a first face 21 and a second face 22 opposite thereto; a magnetoresistance effect element 3 provided on the first surface 21 of the substrate 2; a bias magnetic field generating unit 4 capable of applying a bias magnetic field to a part of the magnetoresistive element 3; an arithmetic processing unit 5 that calculates a physical quantity based on an output signal from the magnetoresistance effect element 3; and a sealing unit (not shown) that integrally seals the substrate 2, the magnetoresistance effect element 3, the bias magnetic field generating unit 4, and the arithmetic processing unit 5 with a sealing resin and that is formed into a chip as a whole. The sealing portion may integrally seal at least the substrate 2, the magnetoresistance effect element 3, and the bias magnetic field generating portion 4 with resin.

The substrate 2 may be a rectangular substrate on which the magnetoresistance effect element 3 can be mounted, and examples thereof include: a semiconductor substrate such as a silicon wafer; ceramic substrates such as AlTiC substrates and alumina substrates; a resin substrate; a glass substrate, and the like. Al may be provided on the first surface 21 of the substrate 2 corresponding to the kind of the substrate 2₂O₃And the like.

In this embodiment, the magnetoresistance effect element 3 is of a spin valve type. As such a magnetoresistive element 3, for example, an MR element such as a TMR element or a GMR element can be used. The magnetoresistive effect element 3 includes an MR laminate 60 (see fig. 7) including a free layer 61, a nonmagnetic layer 62, a magnetization pinned layer 63, and an antiferromagnetic layer 64, which are laminated in this order from the substrate 2 side. The antiferromagnetic layer 64 is made of an antiferromagnetic material, and plays a role of fixing the direction of magnetization of the magnetization pinned layer 63 by causing exchange coupling with the magnetization pinned layer 63. The magnetoresistance effect element 3 may have a structure in which an antiferromagnetic layer 64, a magnetization pinned layer 63, a nonmagnetic layer 62, and a free layer 61 are stacked in this order from the substrate 2 side. The antiferromagnetic layer 64 may be omitted if the magnetization Pinned layer 63 has a laminated ferromagnetic structure of a ferromagnetic layer, a nonmagnetic interlayer, and a ferromagnetic layer, and the two ferromagnetic layers are antiferromagnetically coupled to each other to form a so-called Pinned-Pinned layer (SFP layer).

In the TMR element, the nonmagnetic layer 62 is a tunnel barrier layer. In the GMR element, the nonmagnetic layer 62 is a nonmagnetic conductive layer. In the TMR element and the GMR element, the resistance value changes according to the angle formed by the direction of magnetization of the free layer 61 and the direction of magnetization of the magnetization fixed layer 63. The resistance value is smallest when the angle is 0 ° (the magnetization directions of each other are parallel), and the resistance value is largest when the angle is 180 ° (the magnetization directions of each other are antiparallel).

The magnetoresistance effect element 3 includes: a plurality of elongated portions 31 having first and second ends 311 and 312 and extending in a first direction (X-axis direction); and a folded portion 32 which connects the ends (first end 311 and second end 312) of the plurality of long-shaped portions 31 and which constitutes the magnetoresistive element 3 in a meandering (meandering) manner. The folded portion 32 includes: a plurality of first folded portions 321 connecting between the first end portions 311 of the plurality of elongated portions 31 adjacent in the second direction (Y-axis direction), and a plurality of second folded portions 322 connecting between the second end portions 312. The elongated portion 31, the first folded portion 321, and the second folded portion 322 are all aligned in the second direction (Y-axis direction). Further, the first folded portion 321 and the second folded portion 322 may not be aligned in the second direction (Y-axis direction). Since the GMR element as the magnetoresistance effect element 3 generally has a relatively low element resistance value, it is necessary to narrow the line width and to lengthen the line length in order to output a signal of a predetermined intensity from the magnetic sensor device 1. In order to narrow the line width and increase the line length of the GMR element in a limited region on the first surface 21 of the substrate 2, the GMR element is preferably configured in a zigzag manner as described above. In addition, since the TMR element as the magnetoresistance effect element 3 is generally relatively high in element resistance value, high withstand voltage performance can be achieved by connecting a plurality of TMR elements in series, and a signal of a prescribed intensity can be output from the magnetic sensor device 1. In order to connect a plurality of TMR elements in series in a limited region on the first surface 21 of the substrate 2, the TMR element is preferably configured in a zigzag manner as described above.

The magnetoresistive element 3 configured in a zigzag manner may be constituted by the MR laminated body 60 as a whole, and a pad (electrode pad) 80 may be connected to one end of the zigzag MR laminated body 60 via a lead electrode 70 or the like (see fig. 1 and 2), or a plurality of MR laminated bodies 60 having a substantially circular shape in plan view may be connected in series in a zigzag manner via an upper lead electrode 71 and a lower lead electrode 72 (see fig. 3 to 6). The lead electrode 70 (see fig. 1 and 2), the upper lead electrode 71, and the lower lead electrode 72 (see fig. 3 to 6) are made of, for example, one conductive material or a composite film of two or more conductive materials such as Cu, Al, Au, Ta, and Ti. The shape of the MR laminated body 60 is not limited to a substantially circular shape in plan view, and may be a substantially elliptical shape in plan view (see fig. 5 and 6), a substantially rectangular shape in plan view, or the like.

In the embodiment shown in fig. 3 to 6, a plurality of lower lead electrodes 72 are provided on the substrate 2. Each of the plurality of lower lead electrodes 72 has an elongated substantially rectangular shape, and is provided with a predetermined gap between two lower lead electrodes 72 adjacent in the electrical series direction of the plurality of MR laminated bodies 60 arranged in an array. The MR laminated body 60 is provided near both ends of the lower lead electrode 72 in the longitudinal direction. Two MR layered bodies 60 are provided on the lower lead electrode 72, respectively.

The plurality of upper lead electrodes 71 are provided on the plurality of MR laminated bodies 60. In the embodiment shown in fig. 3 and 4, each upper lead electrode 71 has an elongated substantially rectangular shape. The upper lead electrodes 71 are arranged such that a predetermined gap is provided between two upper lead electrodes 71 adjacent in the electrical series direction of the plurality of MR laminated bodies 60 arranged in an array, and the plurality of MR laminated bodies 60 are connected in series in a zigzag manner, and the antiferromagnetic layers 64 of the adjacent two MR laminated bodies 60 are electrically connected to each other. In the embodiment shown in fig. 5 and 6, the upper lead electrode 71 includes: a first elongated substantially rectangular upper lead electrode 711 which connects the plurality of MR laminated bodies 60 arranged in the X-axis direction in series; and second upper lead electrodes 712 positioned at both ends of each of the elongated portions 31 and connected to the substantially U-shape of the two MR laminated bodies 60 adjacent in the Y-axis direction. The MR stacks 60 are connected in series in a zigzag manner by the first upper lead electrode 711 and the second upper lead electrode 712. The elongated portion 31 is configured by the plurality of MR stacks 60 arranged in the X-axis direction and the first upper lead electrode 711 connected in series, and the folded portion 32 (the first folded portion 321 and the second folded portion 322) is configured by the MR stacks 60 located at both ends of the plurality of MR stacks 60 arranged in the X-axis direction and the second upper lead electrode 712 connected in the Y-axis direction. Further, a gap layer (protective layer) may be provided between the free layer 61 and the lower lead electrode 72 or the upper lead electrode 71.

In the present embodiment, the circuit configuration of the magnetic sensor device 1 may be a half-bridge circuit (see fig. 2 and 6) in which the magnetoresistive elements 3 (the first magnetoresistive element 3A and the second magnetoresistive element 3B) provided on the first surfaces 21 of the two substrates 2 are connected in series, or may be a wheatstone bridge circuit in which the two magnetoresistive elements 3 (the first magnetoresistive element and the second magnetoresistive element) provided on the first surface 21 of one substrate 2 and the four magnetoresistive elements 3 (the first to fourth magnetoresistive elements) of the two magnetoresistive elements 3 (the third magnetoresistive element and the fourth magnetoresistive element) provided on the first surface 21 of the other substrate 2 are bridged. Note that, in the wheatstone bridge circuit, the four magnetoresistance effect elements 3 (first to fourth magnetoresistance effect elements) may be provided on the first surface 21 of the single substrate 2, respectively.

The half-bridge circuit includes a power supply port V, a ground port G, an output port E, and a first magnetoresistance effect element 3A and a second magnetoresistance effect element 3B connected in series. One end of the first magnetoresistance element 3A is connected to the power supply port V. The other end of the first magnetoresistance effect element 3A is connected to one end of the second magnetoresistance effect element 3B and the output port E. The other end of the second magnetoresistance element 3B is connected to the ground port G. At the power supply port V, a constant current source V is connected_CCA power supply voltage (constant current) of a predetermined magnitude is applied, and the ground port G is connected to the ground GND.

In this embodiment, the magnetization direction (solid-line arrow shown in fig. 8) of the magnetization pinned layer 63 in the first magnetoresistance element 3A and the magnetization direction (solid-line arrow shown in fig. 8) of the magnetization pinned layer 63 in the second magnetoresistance element 3B are antiparallel to each other. The magnetization direction (open arrow shown in fig. 8) of the free layer 61 of the first magnetoresistance element 3A and the magnetization direction (open arrow shown in fig. 8) of the free layer 61 of the second magnetoresistance element 3B in the initial state (state where no external magnetic field is applied) are parallel to each other and orthogonal to the magnetization direction of the magnetization fixed layer 63. Since the magnetization directions of the magnetization pinned layer 63 and the free layer 61 of the first magnetoresistance element 3A and the second magnetoresistance element 3B are the above directions, the potential difference of the output port E changes with a change in the resistance value of the magnetoresistance element 3 (the first magnetoresistance element 3A and the second magnetoresistance element 3B) according to the external magnetic field, and a signal as a change in the potential difference thereof is output.

In the present embodiment, one end of the magnetoresistance effect element 3 is connected to a pad (electrode pad) 80 formed on the first surface 21 of the substrate 2. A constant current source is connected to the pad (electrode pad) 80 via a Bonding wire (Bonding wire)4, for example. The bonding wire 4 is fixed to a pad (electrode pad) 80 so as to extend over a part of the magnetoresistive element 3 on the first surface 21 of the substrate 2 in a zigzag manner. More specifically, the bonding wire 4 overlaps the first folded portion 321 of the zigzag magnetoresistance effect element 3 when viewed from above the first surface 21 of the substrate 2.

In the magnetoresistance effect element 3, fluctuation in magnetization of the free layer 61 is generated in a zero magnetic field (initial state where no external magnetic field is applied). By causing the bonding wire 4 to extend over a part of the magnetoresistive element 3, a magnetic field (bias magnetic field) generated by a current flowing through the bonding wire 4 is applied to the magnetoresistive element 3, and as a result, fluctuation in magnetization of the free layer 61 can be suppressed. That is, the bonding wire 4 extending over a part of the magnetoresistive element 3 is a current path and is a bias magnetic field generator 4 for applying a bias magnetic field to the magnetoresistive element 3.

Since the current flowing through the bonding wire 4 is a constant current supplied from a constant current source, the strength of the magnetic field (current magnetic field) generated by the bonding wire 4 is generally substantially constant, and the direction in which the magnetic field is applied to the magnetoresistance effect element 3 is also substantially constant. Therefore, in the present embodiment, even when the magnetic sensor device 1 (bonding wire 4) is exposed to a large external magnetic field or physical impact is applied to the magnetic sensor device 1 (bonding wire 4), the magnetic field (bias magnetic field) generated by the bonding wire 4 can be stably applied to the magnetoresistive element 3.

The direction of current flowing through the elongated portion 31 of the meandering magnetoresistance effect element 3 and the direction of current flowing through the folded portion 32 (the first folded portion 321 and the second folded portion 322) are different from each other. The direction of the current in the elongated portion 31 is substantially parallel to the first direction (X-axis direction), whereas the direction of the current in the folded portion 32 (the first folded portion 321 and the second folded portion 322) is substantially orthogonal to the first direction (X-axis direction) (second direction (Y-axis direction)) or a direction intersecting the first direction (X-axis direction). In this way, since the current directions of the long-sized portion 31 and the folded portion 32 (the first folded portion 321 and the second folded portion 322) are different from each other, the change in the resistance value according to the external magnetic field in the long-sized portion 31 is different from the change in the resistance value according to the external magnetic field in the folded portion 32 (the first folded portion 321 and the second folded portion 322). The output voltage from the magnetoresistance effect element 3 is a value corresponding to the change in the resistance value of the entire magnetoresistance effect element 3, but the change in the resistance value in the folded portion 32 (the first folded portion 321 and the second folded portion 322) causes noise. In the present embodiment, since a relatively strong bias magnetic field is applied to the folded portion 32 (first folded portion 321) relatively close to the bonding wire 4 by causing the bonding wire 4 to straddle above the folded portion 32 (first folded portion 321) of the zigzag magnetoresistance effect element 3, the magnetization direction of the free layer 61 in the folded portion 32 (first folded portion 321) is difficult to change regardless of the application of the external magnetic field to be detected. On the other hand, since a relatively weak bias magnetic field is applied to the long-shaped portion 31 relatively distant from the bonding wire 4, the magnetization direction of the free layer 61 in the long-shaped portion 31 changes in accordance with the application of the external magnetic field to be detected. Therefore, in the resistance value change of the entire magnetoresistance effect element 3, the contribution rate of the resistance value change in the folded portion 32 (the first folded portion 321 and the second folded portion 322) becomes relatively small. As a result, noise (variation in the resistance value in the folded portion 32 (the first folded portion 321 and the second folded portion 322)) appearing in the output voltage from the magnetoresistance effect element 3 can be reduced, and detection accuracy in the magnetic sensor device 1 can be improved. Note that the current direction is a current flow direction when the flow of current in the magnetoresistance effect element 3 (the long strip portion 31 and the folded portion 32 (the first folded portion 321 and the second folded portion 322)) is projected on an arbitrary plane parallel to the XY plane (a plane formed by the X axis and the Y axis).

In the case where the magnetization direction of the magnetization pinned layer 63 of the magnetoresistive element 3 is the X-axis direction and the magnetization direction of the free layer 61 is not orthogonal to each other, the magnetization direction of the free layer 61 can be corrected to be orthogonal to the magnetization direction of the pinned layer 63 by the bias magnetic field applied from the bonding wire 4. For example, in the case where the magnetization direction of the magnetization pinned layer 63 of the magnetoresistance effect element 3 is the-X direction and the angle formed by the magnetization directions of the magnetization pinned layer 63 and the free layer 61 exceeds 90 ° (for example, exceeds 90 ° and is 100 ° or less), or in the case where the magnetization direction of the magnetization pinned layer 63 of the magnetoresistance effect element 3 is the + X direction and the angle formed by the magnetization directions of the magnetization pinned layer 63 and the free layer 61 is less than 90 ° (for example, 80 ° or more and less than 90 °), if a current flows in the + Y direction at the bonding wire 4, a bias magnetic field in the-X direction is generated from the bonding wire 4 and applied to the magnetoresistance effect element 3. Thus, the magnetization direction of the free layer 61 can be corrected to be orthogonal to the magnetization direction of the magnetization pinned layer 63.

Further, in the present embodiment, since the magnetic field generated from the bonding wire 4 can be applied to the magnetoresistance effect element 3, the magnetic sensor device 1 can be self-tested by adjusting the value of the current flowing through the bonding wire 4. Specifically, a power supply from a constant current power supply is supplied to the magnetic sensor device 1 and a current flows through the bonding wire 4 in a zero magnetic field (an initial state where no external magnetic field is applied) or a state where an external magnetic field of a predetermined intensity is continuously applied without changing the intensity. The applied voltage Vdd is varied within a predetermined range, and the output voltage Vout of each applied voltage Vdd is obtained. By comparing the ratio (Vout/Vdd) of the applied voltage Vdd and the output voltage Vout with a predetermined constant (1/2+1/2 × kRS), the characteristics of the magnetic sensor device 1 can be evaluated.

Wherein k represents "a current value I flowing through the bonding wire 4₄(mA) and a magnetic field H generated from the bonding wire 4₄Constant (H) between (mT)₄＝k×I₄) R denotes "the resistance value (Ω) of the magnetoresistance effect element 3 calculated from the applied voltage Vdd and the current value supplied from the constant current power supply", and S denotes "the design value of the sensitivity of the magnetic sensor device 1".

Above the magnetoresistive element 3, the bonding wire 4 is preferably provided substantially parallel to the first surface 21 of the substrate 2. If the bonding wire 4 is not substantially parallel to the first surface 21 of the substrate 2, the entire distance of the folded portion 32 (first folded portion 321) of the magnetoresistance effect element 3 from the bonding wire 4 becomes different, and the strength of the bias magnetic field applied to the free layer 61 of each folded portion 32 (first folded portion 321) is different. However, since the bonding wires 4 are substantially parallel to the first surface 21 of the substrate 2, the distances from the respective folded portions 32 (first folded portions 321) to the bonding wires 4 can be set to be substantially the same, and therefore, the strengths of the bias magnetic fields applied to the free layers 61 of the respective folded portions 32 (first folded portions 321) can be set to be substantially the same.

The interval between the magnetoresistive element 3 and the bonding wire 4 (the interval in the Z-axis direction) is set appropriately so that a bias magnetic field is applied to reduce the fluctuation of magnetization of the free layer 61 of the magnetoresistive element 3, and preferably so that the change in resistance value in the folded portion 32 (the first folded portion 321) can be reduced regardless of the application of the external magnetic field. In the present embodiment, the magnetoresistive element 3 and the bonding wire 4 are integrated by a sealing portion. That is, the sealing resin constituting the sealing portion is located in the gap therebetween. Thus, the bonding wire 4 is positioned on a layer different from the magnetoresistive element 3 via the sealing resin.

The arithmetic processor 5 includes: an a/D (analog-to-digital) conversion unit 51 that converts an analog signal (sensor signal S) output from the magnetoresistance effect element 3 into a digital signal; and an arithmetic unit 52 for performing arithmetic processing on the digital signal converted by the a/D conversion unit 51. As a result of the calculation by the calculation unit 52, a signal corresponding to the external magnetic field can be output.

The a/D conversion section 51 converts the sensor signal S output from the magnetoresistance effect element 3 into a digital signal, and the digital signal is input to the operation section 52. The arithmetic unit 52 performs arithmetic processing on the digital signal converted from the analog signal by the a/D converter 51. The arithmetic unit 52 is configured by, for example, a microcomputer or an ASIC (Application specific integrated Circuit).

In the magnetic sensor device 1 having the above-described configuration, since the bonding wire 4 functioning as the bias magnetic field generating unit 4 for applying a bias magnetic field to the magnetoresistance effect element 3 is located in a layer different from the magnetoresistance effect element 3 (above the magnetoresistance effect element 3), the bias magnetic field can be stably applied to the free layer 61 of the magnetoresistance effect element 3, and fluctuation (variation) in magnetization of the free layer 61 can be suppressed.

In the magnetic sensor device 1, since the bonding wire 4 is positioned above the folded portion 32 (first folded portion 321) of the magnetoresistance effect element 3 configured in a zigzag manner, noise (a change in resistance value in the folded portion 32 (first folded portion 321)) occurring in the output voltage from the magnetoresistance effect element 3 can be reduced, and detection accuracy in the magnetic sensor device 1 can be improved.

The above-described embodiments are described in order to facilitate understanding of the present invention, and are not described in order to limit the present invention. Therefore, each element disclosed in the above embodiments is intended to include all design modifications or equivalents falling within the technical scope of the present invention.

In the above-described embodiment, the magnetic sensor device 1 has the constant current source as the power supply, and the constant current from the constant current source flows through the bonding wire 4, whereby the stable bias magnetic field (current magnetic field) is applied to the free layer 61 of the magnetoresistance effect element 3, but the present invention is not limited to this embodiment as long as the current flowing through the bonding wire 4 is substantially constant. For example, the magnetic sensor device 1 may also have a constant voltage source as a power supply. In the magnetic sensor device 1 according to the above-described embodiment, although the resistance values of the respective magnetoresistance effect elements 3 (for example, the first magnetoresistance effect element 3A and the second magnetoresistance effect element 3B) are different from each other according to a change in the magnetization direction of the free layer 61 in response to application of the external magnetic field, the combined resistance value of the plurality of magnetoresistance effect elements 3 as a whole is substantially constant. Therefore, by having a constant voltage source as a power source and flowing a constant voltage current to the bonding wire 4, a substantially constant current flows through the bonding wire 4. As a result thereof, a bias magnetic field (current magnetic field) can be applied to the free layer 61 of the magnetoresistance effect element 3.

In the above embodiment, the bonding wire 4 is provided above the first folded portion 321 of the magnetoresistance effect element 3, but the present invention is not limited to this embodiment. For example, in the magnetic sensor device 1, the bonding wire 4 may be provided above the second folded portion 322 of the magnetoresistance effect element 3, or the bonding wire 4 may be provided above each of the first folded portion 321 and the second folded portion 322.

In the above-described embodiment, the first folded portion 321 and the second folded portion 322 of the magnetoresistance effect element 3 are connected between the first ends 311 and between the second ends 312 so as to be folded in the direction orthogonal to the longitudinal direction of the long strip portion 31 (see fig. 1 to 4), but the present invention is not limited to this embodiment. For example, as shown in fig. 10, the first folded portion 321 and the second folded portion 322 may have a substantially V-shape or a substantially U-shape connecting between the first ends 311 and the second ends 312 of the elongated portion 31.