TWI739107B - Magnetic field sensing apparatus - Google Patents

Abstract

A magnetic field sensing device includes at least one magnetoresistive sensor to set the element in the magnetization direction. The magnetization direction setting element is arranged beside at least one magnetoresistive sensor. The magnetization direction setting element has a current inlet and a current outlet opposite to each other. At least one magnetoresistive sensor is located between the current inlet and the current outlet, and the orthographic projection of at least a part of the at least one magnetoresistive sensor overlaps with the orthographic projection of the magnetization direction setting element. The magnetization direction setting element further includes a plurality of current path adjustment structures. A plurality of current path adjustment structures are located in the area between the current inlet and the at least one magnetoresistive sensor and used to define the current distribution of the current from the current inlet.

Description

Magnetic field sensing device

The invention relates to a magnetic field sensing device.

When detecting an external magnetic field, the magnetic field sensing device generates a setting magnetic field through the internal magnetization direction setting element to magnetize the magnetoresistive sensor along its extension direction, and thereby set the magnetization of the magnetoresistive sensor direction. The usual practice is to install a current-applying conductor next to the magnetoresistive sensor to generate a set magnetic field to magnetize the magnetoresistive sensor.

Generally speaking, when current enters the conductor, most of the current will flow through the current inlet and travel through the conductor with the smallest impedance path to the current outlet. Due to the above geometrical relationship and the current transmission method, the current will concentrate through a part of the conductor. As a result, the current density distribution inside the conductor is uneven. In addition, the current travel direction will also change with its travel route. Therefore, the strength and direction of the magnetic field generated by different areas of the conductor may be different. The above phenomenon causes the magnetoresistive sensor to be unable to be magnetized uniformly, which affects the measurement result of the subsequent magnetic field sensing device.

The invention provides a magnetic field sensing device, in which the magnetoresistive sensor can be uniformly magnetized and has accurate measurement results.

An embodiment of the present invention provides a magnetic field sensing device, which includes at least one magnetoresistive sensor and a magnetization direction setting element. The magnetization direction setting element is arranged beside at least one magnetoresistive sensor. The magnetization direction setting element has a current inlet and a current outlet opposite to each other. At least one magnetoresistive sensor is located between the current inlet and the current outlet, and the orthographic projection of at least a part of the at least one magnetoresistive sensor overlaps with the orthographic projection of the magnetization direction setting element. The magnetization direction setting element further includes a plurality of current path adjustment structures, and the plurality of current path adjustment structures are located in the area between the current inlet and the at least one magnetoresistive sensor and used to define the current distribution of the current from the current inlet.

In an embodiment of the present invention, the aforementioned current path adjustment structures include a first current path adjustment structure, a second current path adjustment structure, and a third current path adjustment structure that are different from each other.

In an embodiment of the present invention, the aforementioned first current path adjusting structure includes at least one opening.

In an embodiment of the present invention, the shape of the at least one opening described above includes a circle, an ellipse, a triangle, a quadrilateral, or a polygon.

In an embodiment of the present invention, the above-mentioned second current path adjustment structure is a slope structure, and the second current path adjustment structure is located at least on one side of the current inlet.

In an embodiment of the present invention, the aforementioned third current path adjustment structure includes a notch.

In an embodiment of the present invention, a reference axis is defined. The reference axis is set at the center of the element through the magnetization direction. The reference shaft has opposite first and second sides. The current inlet is located on the first side. The current outlet is located on the second side. The notch is on the first side.

In an embodiment of the present invention, the above-mentioned current path adjusting structures include at least one opening, a gap, an inclined surface structure and a combination thereof.

In an embodiment of the present invention, the above-mentioned magnetic field sensing device further includes a current generator. The current generator is used to generate the above-mentioned current. The current generator is coupled with the magnetization direction setting element. The current enters the magnetization direction setting element from the current inlet and leaves the magnetization direction setting element from the current outlet.

In an embodiment of the present invention, the type of the aforementioned magnetoresistive sensor is an anisotropic magnetoresistive sensor.

Based on the above, in the magnetic field sensing device of the embodiment of the present invention, a plurality of current path adjustment structures are located between the current inlet of the magnetization direction setting element and at least one magnetoresistive sensor. Before the current flows through the magnetoresistive sensor, these current path adjustment structures can adjust the current path to define the current distribution of the current so that the current is uniformly transmitted in the same direction. Therefore, the magnetization direction setting element can uniformly magnetize the magnetoresistive sensor, so that the magnetic field sensing device has an accurate measurement result.

In order to make the above-mentioned features and advantages of the present invention more comprehensible, the following specific embodiments are described in detail in conjunction with the accompanying drawings.

FIG. 1 is a schematic top view of a magnetic field sensing device according to an embodiment of the invention. 2A and 2B are different layout methods of the anisotropic magnetoresistive sensor in FIG. 1. FIG. 3 is a schematic top view of a magnetic field sensing device of a comparative embodiment. Fig. 4A is a diagram showing the relationship between current intensity and distance of the section A-A' in Fig. 1. Fig. 4B is a diagram showing the relationship between current intensity and position of the section B-B' in Fig. 3.

1, in this embodiment, the magnetic field sensing device 100 includes at least one magnetoresistive sensor 110 (for example, two), a magnetization direction setting element 120, and a plurality of magnetization direction setting elements 12 (for example, two ) And the current generator 130, wherein the magnetization direction setting element 120 includes a plurality of current path adjustment structures 122, and the magnetization direction setting element 12 does not have a current path adjustment structure 122. The above components will be explained in detail in the following paragraphs.

The magnetoresistive sensor 110 referred to in the embodiment of the present invention refers to a sensor whose resistance can be changed correspondingly through changes in an external magnetic field. In this example, the magnetoresistive sensor 110 may be an Anisotropic Magneto-Resistive resistor (AMR resistor). 2A and 2B, the anisotropic magnetoresistive sensor 110 has, for example, a barber pole-like structure, that is, its surface is provided with an extension direction D relative to the anisotropic magnetoresistive sensor 110 A plurality of electrical shorting bars SB extending at an oblique angle of 45 degrees, these shorting bars SB are spaced apart from each other and arranged in parallel on the ferromagnetic film (ferromagnetic film) FF, and the ferromagnetic film FF is anisotropic magnetoresistive inductance The extension direction of the main body of the sensor 110 is the extension direction of the anisotropic magnetoresistive sensor 110. The sensing direction SD of the anisotropic magnetoresistive sensor 110 is perpendicular to the extending direction D. In addition, the opposite ends of the ferromagnetic film FF can be made tapered.

The magnetization direction setting elements 12 and 120 referred to in the embodiment of the present invention can be coils, wires, metal sheets, other suitable electrical conductors, or any combination of the foregoing elements that generate a magnetic field by passing current. The magnetization direction setting elements 12 and 120 respectively have a current inlet E and a current outlet O opposite to each other.

The current path adjusting structure 122 (or current path limiting structure) referred to in the embodiment of the present invention generally refers to a structure that is functionally used to adjust/limit a current path. The current path adjusting structure 122 may be an opening in the magnetization direction setting element 120, a slope structure, a notch, or a combination thereof, and the present invention is not limited thereto. For example, the magnetization direction setting element 120 includes first, second, and third current path adjustment structures 122a, 122b, and 122c that are different from each other. In the embodiment of the present invention, the first current path adjusting structure 122a can, for example, increase the resistance value of a partial area of the magnetization direction setting element 120, and the specific structure thereof is, for example, an opening, but it is not limited thereto. The shape of the opening is, for example, a circle, an ellipse, a triangle, a quadrilateral, or a polygon, but it is not limited thereto. The second current path adjusting structure 122b is, for example, a structure that can adjust/limit the current path, and its specific structure is, for example, a slope structure, but it is not limited thereto. The third current path adjustment structure 122c is, for example, a structure that can compensate for the geometric configuration relationship between the current inlet E and the current outlet O. The specific structure thereof is, for example, a gap connected to the outside, but is not limited to this.

The current generator 130 referred to in the embodiment of the present invention refers to an electronic component used to provide a current I.

The component arrangement of the magnetic field sensing device 100 will be described in detail in the following paragraphs.

Please refer to FIG. 1, the magnetization direction setting elements 12 and 120 are disposed beside at least one magnetoresistive sensor 110, and the orthographic projection of at least a part of the magnetoresistive sensor 110 overlaps with the orthographic projection of the magnetization direction setting element 120. In detail, the two magnetization direction setting elements 12 are respectively arranged under the edge part EP of the magnetoresistive sensor 110, and the magnetization direction setting element 120 is arranged under the central part MP of the magnetoresistive sensor 110 (that is, the magnetic The orthographic projection of the central part MP of the resistance sensor 110 overlaps with the orthographic projection of the magnetization direction setting element 120). In other embodiments, the magnetization direction setting elements 12 and 120 may also be disposed above the at least one magnetoresistive sensor 110, and the invention is not limited to this. In other words, the magnetization direction setting elements 12 and 120 are respectively used to set the magnetization directions of the edge portion EP and the central portion MP of the magnetoresistive sensor 110.

1 again, the magnetization direction setting element 120 can be divided into a first part P1 (upper part) and a second part P2 (lower part). The first part P1 is adjacent to the current inlet E, and the second part P2 is adjacent to the current outlet O. These current path adjusting structures 120 are located in the area between the current inlet E and the at least one magnetoresistive sensor 110. In other words, these current path adjusting structures 120 are provided in the first part P1.

In detail, in the first part P1, the first current path adjusting structure 122a (opening) is provided between the current inlet E and the second part P2. The second current path adjusting structure 122b (inclined structure) is located on opposite sides of the current inlet E, and forms an area with a width gradual to the direction D1, so that the shape of the first part P1 looks like a trapezoid shape, wherein the trapezoid-like shape The range of the base angle θ can be in the range of 20 degrees to 70 degrees, and the present invention is not limited thereto. The position of the third current path adjustment structure 122c is set according to the position asymmetry between the current inlet E and the current outlet O. A reference axis R passing through the center of the magnetization direction setting element 120 is defined. The reference axis R has opposite first and second sides S1, S2. The current inlet E is located on the first side S1 (right side), the current outlet O is located on the second side S2 (left side), and the third current path adjusting structure 122c is located on the first side S1 on the same side of the current inlet E.

In addition, the current generator 130 is coupled to the magnetization direction setting elements 12, 120 through wires, and is used to provide a current I to the magnetization direction setting elements 12, 120 to generate a set magnetic field with the direction of the magnetic field as the direction D2. The spiral manner is coupled to the magnetization direction setting elements 12 and 120. It should be noted that in this embodiment, since the magnetization direction setting elements 12 and 120 are disposed under the magnetoresistive sensor 110, a set magnetic field with the magnetic field direction of the magnetoresistive sensor 110 in the direction D2 can be provided. In other embodiments, the magnetization direction setting elements 12, 120 may be arranged above the magnetoresistive sensor 110, so that the magnetization direction setting elements 12, 120 provide the magnetic field direction of the magnetoresistive sensor 110 as the opposite of the direction D2. The direction of a set magnetic field, the present invention is not limited to this.

In order to explain the use of the magnetic field direction setting element 120 and the current path adjusting structure 122 of the present invention, the basic principle of the magnetic field sensing device 100 of the embodiment of the present invention for measuring the magnetic field will be introduced in the following paragraphs.

Before the anisotropic magnetoresistive sensor 110 starts to measure the external magnetic field H, its magnetization direction can be set by the magnetization direction setting element 120 first. In FIG. 2A, the magnetization direction setting element 120 can generate a magnetic field along the extension direction D (or the long axis direction) by energization, so that the anisotropic magnetoresistive sensor 110 has a magnetization direction M.

Then, the magnetization direction setting element 120 is not energized, so that the anisotropic magnetoresistive sensor 110 starts to measure the external magnetic field H. When there is no external magnetic field H, the magnetization direction M of the anisotropic magnetoresistive sensor 110 is maintained in the extension direction D. At this time, the current generator 130 can apply a current I to change the current I from the anisotropic magnetoresistive sensor. If the left end of the detector 110 flows to the right end, the current I near the shorting bar SB will flow perpendicular to the extension direction of the shorting bar SB, and the current I near the shorting bar SB will flow 45 degrees with the magnetization direction M. The resistance value of the directional magnetoresistive sensor 110 is R.

When an external magnetic field H faces a direction perpendicular to the extension direction D, the magnetization direction M of the anisotropic magnetoresistive sensor 110 will be deflected to the direction of the external magnetic field H, so that the magnetization direction and the current I near the shorting bar flow The included angle of is greater than 45 degrees. At this time, the resistance value of the anisotropic magnetoresistive sensor 110 changes by -ΔR, that is, R-ΔR, that is, the resistance value becomes smaller, where ΔR is greater than zero.

However, as shown in FIG. 2B, when the extension direction of the shorting bar SB in FIG. 2B is set at 90 degrees to the extension direction of the shorting bar SB in FIG. 2A (at this time, the extension direction of the shorting bar SB in FIG. 2B is still It is 45 degrees between the extension direction D of the anisotropic magnetoresistive sensor 110), and when there is an external magnetic field H, in addition, the magnetic field H will still deflect the magnetization direction M to the direction of the external magnetic field H. At this time, the magnetization direction The angle between M and the current I near the shorting bar SB will be less than 45 degrees, so the resistance value of the anisotropic magnetoresistive sensor 110 will become R+ΔR, which is the resistance value of the anisotropic magnetoresistive sensor 110 Get bigger.

In addition, when the magnetization direction M of the anisotropic magnetoresistive sensor 110 is set to the reverse direction shown in FIG. 2A by the magnetization direction setting element 120, the anisotropic magnetoresistive sensor of FIG. The resistance value of the detector 110 becomes R+ΔR. Furthermore, when the magnetization direction M of the anisotropic magnetoresistive sensor 110 is set to the reverse direction as shown in FIG. 2B by the magnetization direction setting element 120, the anisotropic magnetoresistance of FIG. 2B under the external magnetic field H is thereafter The resistance value of the sensor 110 will become R-ΔR

Therefore, the magnetic field sensing device 100 of the embodiment of the present invention can form one or more Wheatstone bridges by using more than four magnetoresistive sensors 110. Those skilled in the art can use these magnetoresistive sensors. The detector 110 is matched with different circuit designs and the above-mentioned resistance value changes to correspondingly measure the signals of the magnetic field components of the external magnetic field H in different directions. Alternatively, in this embodiment, the magnetic field sensing device 100 may also have only one to three magnetoresistive sensors 110. The magnetic field sensing device 100 can learn the change of the magnetic field only by a response signal generated by the respective magnetoresistive sensor 110 to the change of the external magnetic field H. In this embodiment, two magnetoresistive sensors 110 are shown as an example, and the number of magnetoresistive sensors 110 is not limited in the present invention.

It can be seen from the above that before measuring the external magnetic field H, it is necessary to set the magnetization direction of the magnetoresistive sensor 110 through the magnetization direction setting element 120. The effect of each current path adjusting structure 122 in the magnetization direction setting element 120 will be described in detail in the following paragraphs.

In order to illustrate the effect of the current path adjustment structure 122 of this embodiment, FIG. 3 shows a schematic top view of a magnetic field sensing device 10 of a comparative embodiment. The magnetic field sensing device 10 is similar to the magnetic field sensing device 100 of FIG. The difference is that the magnetization direction setting element 120' also includes a first part P1' adjacent to the current inlet E and a second part P2' adjacent to the current outlet O, wherein the first part P1' does not have any current The path adjustment structure, and the shape of the first part P1' is a rectangle. In addition, in the following paragraphs, the so-called magnetic field setting parts of the magnetic field direction setting elements 12 and 120 refer to the part of the magnetization direction setting elements 12 and 120 that overlaps the magnetoresistive sensor 110, that is, the oblique lined part.

Please refer to FIG. 3 first. After the current generator 130 emits a current I, the current I will pass through the two magnetization direction setting elements 12 and the magnetization direction setting element 120' in a spiral path in sequence. In the magnetization direction setting element 120', most of the current I will travel through the current inlet E in the upper right corner and follow the minimum impedance path inside it, while leaving the current outlet O in the lower left corner. Therefore, the right half of the first part P1' has a high current density and a more consistent current flow direction, while the left half has a low current density and a less consistent current flow direction. In other words, the asymmetry of the position of the current inlet E and the current outlet O causes the asymmetry of the current density and flow direction. It can be clearly seen from Fig. 3 that in the magnetic field setting part, most of the current I will flow to the middle region C with the smallest impedance path and have the highest current density, while the current density of the regions A and B on both sides is higher. Small, the outermost area has the lowest current density because there is still a small amount of current flowing along the edge of the rectangle. 4A, it can be seen that the current difference ΔI measured at the center of the magnetic field direction setting element 120' and the edge of the magnetic field direction setting element 12 is relatively large, resulting in inconsistent magnetization in different regions of the magnetoresistive sensor 110. In addition, in the area C of FIG. 3, due to the asymmetry of the positions of the current inlet E and the current outlet O, the current density in the first part P1' is concentrated on the right side, and this phenomenon results in different areas A, B, C flows into the second part P2' in a different direction. For example, in area C, it can be seen that the direction of current I is roughly the direction D3, while in areas A and B, it can be seen that the direction of current I is different from the direction D3, and different current flows will cause the magnetization direction to be set. The direction of the magnetic field generated by the element 120' in different regions A, B, and C is different. The above two conditions cannot make the direction of the magnetic field and the intensity of the magnetic field of each part of the magnetoresistive sensor 120 consistent. In other words, in the comparative embodiment of FIG. 3, the current I cannot uniformly flow to the magnetic field setting part.

Please refer to FIG. 1, similarly, the current I will also sequentially pass through the two magnetization direction setting elements 12 and the magnetization direction setting element 120 in a spiral-like path. In the following paragraphs, the functions of the first to third current path adjustment structures 122a to 122c will be described in sections.

1 again, since the first current path adjustment structure 122a (opening) can increase the impedance in its vicinity, when the current I enters the magnetization direction setting element 120 from the current inlet E, the current I will go in different directions Take a longer path to bypass these first current path adjustment structures 122a and travel toward the current outlet O. In other words, these first current path adjustment structures 122a are used to disperse most of the current, instead of following the path as shown in FIG. 3 The minimum impedance path shown travels and helps the current I to flow into the magnetic field setting part in a uniform manner.

1 and 3, compared with the first part P1' (rectangular area) of FIG. 3, the arrangement of the second current path adjustment structure 122b (inclined structure) of FIG. The volume of the triangular part, so a small part of the current will no longer pass through the omitted triangular part, but will flow to the outermost area along the slope structure. This design helps to increase the current density in the outermost area.

Please refer to FIG. 1, in this embodiment, due to the configuration relationship between the current inlet, the current outlet E, O are asymmetry, because the third current path adjustment structure 122c (notch) is provided with the current inlet E Therefore, when the current I flows in from the current inlet E in the upper right corner, most of the current I will pass to the left of the third current path adjustment structure 122c to bypass the third current path adjustment structure 122c, and go to the lower left The corner of the current outlet moves in the direction of O. This configuration helps to reduce the current density of the current I in the right half of the first part P1 and increase the current density of the left half of the first part P1. At the same time, the current I entering the magnetic field setting part can flow in a more consistent direction.

In view of the above, in the magnetic field sensing device 100 of this embodiment, since the magnetization direction setting element 120 has a plurality of current path adjustment structures 122, and these current path adjustment structures 122 are disposed at the current inlet E and at least one magnetoresistive sensor The area between 110. Therefore, when the current I flows in from the current inlet E, the path of the current I can be adjusted by the current path adjustment structures 122 to define the current distribution of the current and make it uniformly enter the magnetic field setting part, so the magnetoresistive sensor 110 can be uniform. The ground is magnetized by the magnetization direction setting element 120, so that the magnetic field sensing device 100 has an accurate measurement result.

In the above-mentioned embodiment, the central part MP of the magnetoresistive sensor 110 overlaps with the magnetization direction setting element 120 with the current path adjustment structure 122, and the two edge parts EP overlap with the magnetization direction setting element 120 without the current path adjustment structure 122. Magnetization direction setting element 12. In other embodiments, any one, two, or all of the central part MP and the two edge parts EP of the magnetoresistive sensor 110 can also be overlapped with the magnetization direction setting element 120. The present invention does not use This is limited.

In the above-mentioned embodiment, the shape of the first portion P1 is, for example, a trapezoid projecting in a direction opposite to the direction D1. In other embodiments, the shape of the first part is, for example, a trapezoid recessed in the direction D1, and the range of its bottom angle is, for example, 20 degrees to 70 degrees, but it is not limited thereto.

In the above-mentioned embodiment, the magnetization direction setting element 120 is, for example, the first, second, and third current path adjustment structures 122a to 122c with different structures at the same time, that is, the magnetization direction setting element 120 has an opening, a slope structure, and a notch at the same time. In other embodiments, the magnetization direction setting element 120 may also have only the same type of current path adjustment structure. For example, the magnetization direction setting element 120 may also have only a single type of the above-mentioned different structures (for example, only have openings). , Inclined structure or notch), the present invention is not limited to this.

In summary, in the magnetic field sensing device of the embodiment of the present invention, a plurality of current path adjustment structures are located between the current inlet of the magnetization direction setting element and at least one magnetoresistive sensor. Before the current flows through the magnetoresistive sensor, these current path adjustment structures can adjust the current path to define the current distribution of the current so that the current is uniformly transmitted in the same direction. In detail, these current path adjustment structures may include openings, inclined structures, notches, or combinations thereof, which can adjust the impedance of different regions in the first part of the magnetic field direction setting element, adjust/limit the current path, or compensate for current density and current flow. The asymmetry of, to define the current distribution of the current so that the current is uniformly and in the same direction to the magnetic field setting part. Therefore, the magnetization direction setting element can uniformly magnetize the magnetoresistive sensor, so that the magnetic field sensing device has an accurate measurement result.

Although the present invention has been disclosed in the above embodiments, it is not intended to limit the present invention. Anyone with ordinary knowledge in the relevant technical field can make some changes and modifications without departing from the spirit and scope of the present invention. The protection scope of the present invention shall be subject to those defined by the attached patent application scope.

10.100: Magnetic field sensing device 110: Magnetoresistive Sensor 12. 120, 120’: Magnetization direction setting element 122: Current path adjustment structure 122a: The first current path adjustment structure 122b: Second current path adjustment structure 122c: Third current path adjustment structure 130: current generator A, B, C: area A-A’, B-B’: Sectional line D: Extension direction D1, D2: direction E: Current inlet EP: Edge part FF: Ferromagnetic film H: External magnetic field I: current ΔI: current difference M: Magnetization direction MP: central part O: Current outlet P1, P1’: Part One P2, P2’: Part Two S1: First side S2: second side SB: Shorting bar SD: sensing direction θ: bottom angle

FIG. 1 is a top view of a magnetic field sensing device according to an embodiment of the invention. 2A and 2B are different layout methods of the anisotropic magnetoresistive sensor in FIG. 1. FIG. 3 is a schematic top view of a magnetic field sensing device of a comparative embodiment. Fig. 4A is a diagram showing the relationship between current intensity and position of the section A-A' in Fig. 1. Fig. 4B is a diagram showing the relationship between current intensity and position of the section B-B' in Fig. 3.

100: Magnetic field sensing device

110: Magnetoresistive Sensor

12.120: Magnetization direction setting element

122: Current path adjustment structure

122a: The first current path adjustment structure

122b: Second current path adjustment structure

122c: Third current path adjustment structure

130: current generator

A-A’: Cut line

D1, D2: direction

E: Current inlet

EP: Edge part

I: current

M: Magnetization direction

MP: central part

O: Current outlet

P1: Part One

P2: Part Two

S1: First side

S2: second side

SB: Shorting bar

SD: sensing direction

θ: bottom angle

Claims (9)

A magnetic field sensing device, comprising: at least one magnetoresistive sensor; and a magnetization direction setting element arranged beside the at least one magnetoresistance sensor, the magnetization direction setting element having a current inlet and a current outlet opposite to each other , The at least one magnetoresistive sensor is located between the current inlet and the current outlet, and the current inlet and the current outlet are asymmetrically arranged on both sides of the at least one magnetoresistive sensor, And the orthographic projection of at least a part of the at least one magnetoresistive sensor overlaps the orthographic projection of the magnetization direction setting element, wherein the magnetization direction setting element further includes a plurality of current path adjustment structures, and the plurality of The current path adjustment structure is only located in the area between the current inlet and the at least one magnetoresistive sensor, and the plurality of current path adjustment structures are used to define the current inlet from the current inlet and enter the at least one magnetoresistive sensor For the current distribution of a current in front of the detector, the current path adjustment structures include a first current path adjustment structure, a second current path adjustment structure, and a third current path adjustment structure that are different and separately arranged from each other. The magnetic field sensing device according to claim 1 is characterized in that, the first current path adjusting structure includes at least one opening. The magnetic field sensing device according to item 2 of the scope of patent application, wherein the shape of the at least one opening includes a circle, an ellipse, a triangle, a quadrilateral or a polygon. The magnetic field sensing device according to claim 1, wherein the second current path adjusting structure is a slope structure, and the second current path adjusting structure is located on at least one side of the current inlet . The magnetic field sensing device according to item 1 of the scope of patent application, wherein the third current path adjustment structure includes a notch. The magnetic field sensing device according to item 5 of the scope of patent application is characterized in that a reference axis is defined, wherein the reference axis passes through the center of the magnetization direction setting element, and the reference axis has a first side opposite to With the second side, the current inlet is located on the first side, the current outlet is located on the second side, and the gap is located on the first side. According to the magnetic field sensing device described in claim 1, wherein the current path adjustment structures include at least one opening, a notch, an inclined surface structure and a combination thereof. The magnetic field sensing device according to claim 1 is characterized in that it further includes a current generator for generating the current, and the current generator is coupled to the magnetization direction setting element, wherein The current enters the magnetization direction setting element from the current inlet and leaves the magnetization direction setting element from the current outlet. The magnetic field sensing device described in item 1 of the scope of patent application, wherein the type of the magnetoresistive sensor is an anisotropic magnetoresistive sensor.

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