TWI703337B - Magnetic field sensing apparatus - Google Patents

Abstract

A magnetic field sensing apparatus including a magnetic flux concentrator and a plurality of single direction magneto-resistive sensors is provided. The magnetic flux concentrator has a first and a second end portions opposite to each other. The single direction magneto-resistive sensors have the same pinning direction and are disposed beside the magnetic flux concentrator. The single direction magneto-resistive sensors further include a plurality of first and second single direction magneto-resistive sensors. The first single direction magneto-resistive sensors are disposed beside the first end portion and further include a first and a third portions respectively being disposed two opposite sides of the first end portion. The first and a third portions are coupled to a first full Wheatstone bridge. The second single direction magneto-resistive sensors are disposed beside the second end portion and further include a second and a fourth portions respectively being disposed two opposite sides of the second end portion. The second and the fourth portions are coupled to a second full Wheatstone bridge.

Description

Magnetic field sensing device

The present invention relates to a magnetic field sensing device.

With the development of technology, electronic products with navigation and positioning functions are becoming more and more diversified. The electronic compass provides functions equivalent to the traditional compass in the application fields of car navigation, flying and personal handheld devices. In order to realize the function of the electronic compass, the magnetic field sensing device becomes a necessary electronic component.

In order to achieve uniaxial sensing, in general, a giant magnetoresistance (GMR) multilayer film structure or a tunneling magnetoresistance (TMR) multilayer film structure is constructed to form a Wheatstone full bridge, and these magnetic The pinning direction of the barrier multilayer film structure is designed with two pinning directions that are antiparallel to each other. For example, in order to achieve three-axis sensing, six pinning directions that are antiparallel to each other are required. However, designing different pinning directions for the antiferromagnetic layer on the wafer will cause manufacturing difficulties, incur additional costs, and reduce the stability of the pinned layer.

The invention provides a magnetic field sensing device, which is simple to manufacture, low in production cost, and has good stability.

An embodiment of the present invention provides a magnetic field sensing device, including a magnetic flux concentrator and a plurality of unidirectional magnetoresistive sensors. The magnetic flux concentrator has opposite first and second ends. These unidirectional magnetoresistive sensors have the same pinning direction. These unidirectional magnetoresistive sensors are arranged next to the magnetic flux concentrator. These unidirectional magnetoresistive sensors further include a plurality of first unidirectional magnetoresistive sensors and a plurality of second unidirectional magnetoresistive sensors. The first unidirectional magnetoresistive sensors are disposed beside the first end, and the first unidirectional magnetoresistive sensors further include a first part and a third part respectively disposed on opposite sides of the first end. The first part and the third part are coupled to form a first Huisi full bridge. These second unidirectional magnetoresistive sensors are arranged beside the second end. These second unidirectional second magnetoresistive sensors further include a second part and a fourth part respectively disposed on opposite sides of the second end, and the second part and the fourth part are coupled to form a second Huisi full bridge .

In an embodiment of the present invention, the above-mentioned magnetic field sensing device further includes a calculator, which is coupled to these magnetoresistive sensors. The first whistle and full bridge is affected by an external magnetic field and outputs a first electrical signal. The second whistle and full bridge is affected by the external magnetic field and outputs a second electrical signal. The calculator determines the magnetic field components of the external magnetic field in two different directions according to the first electrical signal and the second electrical signal.

In an embodiment of the present invention, the aforementioned magnetoresistive sensors further include a plurality of third unidirectional magnetoresistive sensors. These third unidirectional magnetoresistive sensors are arranged beside the magnetic flux concentrator. The magnetic flux concentrator further includes a middle part. The middle part is at the first end Between the second end and the first end and the second end. At least a part of these third unidirectional magnetoresistive sensors overlaps the middle part.

In an embodiment of the present invention, the aforementioned magnetic field sensing device further includes a time-sharing switching circuit coupled to these magnetoresistive sensors. In the first time interval, the time-sharing switching circuit couples the first part and the third part into a first wheat-same full bridge, and couples the second part and the fourth part into a second wheat-same full bridge, so that the calculation The device determines the magnetic field components of the external magnetic field in the two different directions according to the first electrical signal and the second electrical signal. In the second time interval, the time-sharing switching circuit selects at least a part of the unidirectional magnetoresistive sensors from the first part, the second part, the third part, and the fourth part to couple with these third unidirectional magnetoresistive sensors. Connected to the third Huisi Tongquan bridge. The third whistle and full bridge is affected by the external magnetic field and outputs a third electrical signal. The calculator determines the magnetic field component of the external magnetic field in another direction according to the third electrical signal, wherein the magnetic field component in the other direction is different from the magnetic field components in the two different directions.

In an embodiment of the present invention, the aforementioned third unidirectional magnetoresistive sensors further include a fifth part and a sixth part. The fifth part overlaps with the middle part, and the sixth part further includes two sixth sub-parts. The two sixth sub-parts are respectively arranged on opposite sides of the middle part and not overlapped with the middle part.

In an embodiment of the present invention, the aforementioned magnetic field sensing device further includes a time-sharing switching circuit coupled to these magnetoresistive sensors. In the first time interval, the time-sharing switching circuit couples the first part and the third part into a first wheat-same full bridge, and couples the second part and the fourth part into a second wheat-same full bridge, so that the calculation According to the first electrical signal and the second electrical signal, the device determines the magnetic field distribution of the external magnetic field in two different directions. the amount. In the second time interval, the time-sharing switching circuit selects at least a part of the unidirectional magnetoresistive sensors from the first part, the second part, the third part, and the fourth part to couple with these third unidirectional magnetoresistive sensors. Connected to the third Huisi Tongquan bridge. The third whistle and full bridge is affected by the external magnetic field and outputs a third electrical signal. The calculator determines the magnetic field component of the external magnetic field in another direction according to the third electrical signal, wherein the magnetic field component in the other direction is different from the magnetic field components in the two different directions.

In an embodiment of the present invention, the aforementioned magnetoresistive sensors further include a plurality of third unidirectional magnetoresistive sensors. These third unidirectional magnetoresistive sensors are arranged beside the magnetic flux concentrator and include a fifth part and a sixth part. The magnetic flux concentrator has two short sides and two long sides. Either one of the two short sides is connected to the two long sides. The first end and the second end respectively include a part of two long sides and one of two short sides. The first part and the third part are respectively arranged beside the two long sides belonging to the first end. The second part and the fourth part are respectively arranged beside the two long sides belonging to the second end. The fifth part is arranged beside the short side belonging to the first end and is not arranged to overlap with the first end. The sixth part is arranged beside the short side belonging to the second end and is not arranged to overlap the second end.

In an embodiment of the present invention, the aforementioned magnetic field sensing device further includes a time-sharing switching circuit coupled to these magnetoresistive sensors. In the first time interval, the time-sharing switching circuit couples the first part and the third part into a first wheat-same full bridge, and couples the second part and the fourth part into a second wheat-same full bridge, so that the calculation The device determines the magnetic field components of the external magnetic field in the two different directions according to the first electrical signal and the second electrical signal. In the second time interval, the time-sharing switching circuit couples the fifth part and the sixth part to form a third part. The third whistle and full bridge outputs according to the external magnetic field A third telecommunication signal. The calculator determines the magnetic field component of the external magnetic field in another direction according to the third electrical signal, wherein the magnetic field component in the other direction is different from the magnetic field components in the two different directions.

In an embodiment of the present invention, the aforementioned magnetic field sensing device further includes a unidirectional magnetic field sensing element coupled to the calculator. The unidirectional magnetic field sensing element is affected by the external magnetic field and outputs a third electrical signal. The calculator determines the magnetic field component of the external magnetic field in another direction according to the third electrical signal, where the magnetic field component in the other direction is different from the magnetic field components in the two different directions.

In an embodiment of the present invention, the types of unidirectional magnetoresistive sensors described above include giant magnetoresistive sensors or tunneling magnetoresistive sensors.

Based on the above, in the magnetic field sensing device of the embodiment of the present invention, multi-axis sensing is realized by the pinning directions of the unidirectional magnetoresistive sensors with the same pinning direction, so the manufacturing process is simple, the cost is low, and Has good stability.

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.

100, 100a~100d: Magnetic field sensing device

110: Flux Concentrator

120: Single direction magnetoresistive sensor

122: pinned layer

124: Pinned Layer

126: Interval layer

128: free layer

1201: The first unidirectional magnetoresistive sensor

1202: The second unidirectional magnetoresistive sensor

1203: The third unidirectional magnetoresistive sensor

130: calculator

140: Time-sharing switching circuit

150: Unidirectional magnetic field sensing element

C1~C12: Contact

D1~D3: Direction

E1: Pinning direction

E2: easy magnetization axis

EP1: First end

EP2: second end

H, _HD1 , _HD2 , _HD3 : external magnetic field

H’: External magnetic field after transformation

LE: Long side

LE1: Upper long side

LE2: Lower long side

MP: Middle

P _X , P _Y , P _Z : position

P1: Part One

P2: Part Two

P3: Part Three

P4: Part Four

P5, P5c: Part Five

P6, P6c: Part 6

SP6: Subpart 6

R: resistance

FWH1: First Huisi Tong Quanqiao

FWH2: The second Huisi with the full bridge

FWH3, FWH3b, FWH3c: the third Huisi Tongquanqiao

S: substrate

SD: sensing direction

SE: short side

SE1: Left short side

SE2: Right short side

FIG. 1 is a schematic top view of the structure of a magnetic field sensing device according to an embodiment of the invention.

Figures 2A, 2B, and 2C show the magnetic force transformed by the magnetic flux concentrator when external magnetic fields in different directions are applied to the magnetic field sensing device of Figure 1 Line simulation diagram.

3A is a three-dimensional schematic diagram of the multilayer film structure of the unidirectional magnetoresistive sensor in FIG. 1.

FIG. 3B illustrates the pinning direction of the unidirectional magnetoresistive sensor of FIG. 3A and the easy magnetization axis of the free layer.

FIG. 3C shows the resistance change of the unidirectional magnetoresistive sensor in FIG. 3A under the action of external magnetic fields in different directions and without external magnetic fields.

4A to 4C are schematic diagrams of external magnetic fields placed in different directions by the magnetic field sensing device in FIG. 1.

5A to 7A are schematic top views of magnetic field sensing devices in different embodiments of the present invention in a first time interval.

5B to 7B are schematic top views of the magnetic field sensing device of FIGS. 5A and 7A in a second time interval, respectively.

FIG. 8 is a schematic top view of a magnetic field sensing device according to another embodiment of the invention.

In order to facilitate the description of the configuration of the magnetic field sensing device of the embodiment of the present invention, the magnetic field sensing device can be regarded as being in a space formed by the directions D1, D2, and D3, and the aforementioned directions D1, D2, and D3 are mutually exclusive. vertical.

FIG. 1 is a schematic top view of the structure of a magnetic field sensing device according to an embodiment of the invention. Figures 2A, 2B, and 2C show the lines of force transformed by the magnetic flux concentrator when external magnetic fields in different directions are applied to the magnetic field sensing device of Figure 1 Mock up. 3A is a three-dimensional schematic diagram of the multilayer film structure of the unidirectional magnetoresistive sensor in FIG. 1. FIG. 3B illustrates the pinning direction of the unidirectional magnetoresistive sensor of FIG. 3A and the easy magnetization axis of the free layer. FIG. 3C shows the resistance change of the unidirectional magnetoresistive sensor in FIG. 3A under the action of external magnetic fields in different directions and without external magnetic fields.

In this embodiment, the magnetic field sensing device 100 includes a substrate S, a magnetic flux concentrator 110, a plurality of unidirectional magnetoresistive sensors 120, and a calculator 130. The above components will be explained in detail in the following paragraphs.

In the embodiment of the present invention, the substrate S is, for example, a blank silicon substrate (blank silicon), a glass substrate, or a silicon substrate with integrated-circuit, and the present invention is not limited thereto. In this embodiment, the directions D1 and D2 are, for example, directions parallel to the surface of the substrate S, and the direction D3 is, for example, a direction perpendicular to the surface of the substrate S.

In the embodiment of the present invention, the magnetic flux concentrator 110 refers to an element capable of concentrating the lines of magnetic force of a magnetic field. The material of the magnetic flux concentrator 110 is, for example, a ferromagnetic material with high permeability, such as nickel-iron alloy, cobalt-iron or cobalt-iron-boron alloy, ferrite magnet, or other high-permeability materials, and the present invention is not limited thereto. The following paragraphs will briefly explain how external magnetic fields in different directions are affected by the magnetic flux concentrator 110.

2A, when an external magnetic field H _D1 along the direction D1 is applied, due to the action of the magnetic flux concentrator 110, the magnetic field at the position P _X of the unidirectional magnetoresistive sensor 120 is transformed into The magnetic field of the component in the direction D2 (that is, parallel to the direction D2), so the magnetic field sensing device 100 can sense the magnitude of the external magnetic field in the direction D2 by the unidirectional magnetoresistive sensor 120 to determine the magnetic field in the direction D1 The size of the external magnetic field.

2B again, when an external magnetic field _HD2 along the direction D2 is applied, the magnetic field direction at the position P _Y of the unidirectional magnetoresistive sensor 120 remains substantially under the action of the magnetic flux concentrator 110 In the direction parallel to the direction D2 (ie parallel to the direction D2).

2C again, when an external magnetic field _HD3 along the direction D3 is applied, due to the action of the magnetic flux concentrator 110, the direction of the external magnetic field at the position P _Z of the unidirectional magnetoresistive sensor 120 is changed To a magnetic field with a direction D2 component, the magnetic field sensing module 100 can sense the magnitude of the magnetic field component in the direction D2 by the unidirectional magnetoresistive sensor 120 in the direction D2 to determine the magnitude of the external magnetic field in the direction D3 size.

In the embodiment of the present invention, the unidirectional magnetoresistive sensor 120 refers to a sensor whose resistance can be changed correspondingly by an external magnetic field. Its types include giant magnetoresistive sensors or tunneling magnetoresistive sensors. 3A to 3C, in this embodiment, the unidirectional magnetoresistive sensor 120 includes a pinning layer 122, a pinned layer 124, a spacer layer 126 and Free layer 128. The pinning layer 122 fixes the magnetization direction of the pinned layer 124, which is the pinning direction E1, and the direction of the easy magnetization axis E2 of the free layer 128 can be substantially perpendicular to the pinning direction E1. When the unidirectional magnetoresistive sensor 120 is a giant magnetoresistive sensor, the material of the spacer layer 126 is a non-magnetic metal (non-magnetic metal). In addition, when the unidirectional magnetoresistance sensor 120 is a tunnel magnetoresistance sensor, the material of the spacer layer 126 is an insulating material. It should be noted that in this embodiment, the so-called "single direction" refers to the pinning direction E1 of these magnetoresistive sensors It is the same direction, which is, for example, direction D2.

The graph in FIG. 3C shows the change of the resistance R of the unidirectional magnetoresistive sensor 120 with respect to the external magnetic field H. As shown in the upper left diagram of FIG. 3C, when the unidirectional magnetoresistive sensor 120 is applied with an external magnetic field H in the same direction as the pinning direction E1, its resistance R will decrease, that is, the black dot in the graph corresponds to The value of the resistance R, where the pinning direction is the sensing direction SD of the unidirectional magnetoresistive sensor 120. As shown in the lower left diagram of FIG. 3C, when a unidirectional magnetoresistive sensor 120 is applied with an external magnetic field H in a direction opposite to the pinning direction E1, its resistance R will rise, that is, the black dot in the graph corresponds to The value of the resistance R. As shown in the upper right diagram of FIG. 3C, when the unidirectional magnetoresistive sensor 120 is applied with an external magnetic field H perpendicular to the pinning direction E1, its resistance R remains unchanged, that is, the black dot in the graph corresponds to The value of the resistance R. In addition, as shown in the lower right diagram of FIG. 3C, when the unidirectional magnetoresistive sensor 120 is not applied with a magnetic field, its resistance R remains unchanged, that is, the value of the resistance R corresponding to the black dot in the graph.

In the embodiment of the present invention, the calculator 130 generally refers to a component that receives electrical signals and performs different mathematical operations on the electrical signals. For example, it can perform addition, subtraction, multiplication, division, or a combination thereof, or perform other operations. Different types of mathematical operations are not limited to this invention.

After briefly explaining the functions of the above-mentioned components, the configuration relationship between the components will be described in detail in the following paragraphs.

Please refer to FIG. 1, in this embodiment, the magnetic flux concentrator 110 has first and second end portions EP1 and EP2 and a middle portion MP. The first end EP1 is relative to the second end EP2, where the first end EP1 is, for example, the left end, and the second end EP2 is, for example, Right end, but not limited to this. Moreover, each end EP1, EP2 has opposite upper and lower sides. The middle part MP is connected to the first and second end parts EP1 and EP2. More specifically, the magnetic flux concentrator 110 is, for example, a rectangle, which has two opposite short sides SE and two long sides LE, and any one of the two short sides SE is connected to the two long sides LE. The first end EP1 includes a left short side SE1 and a left part on both sides of the upper long side LE1 and the lower long side LE2. The second end EP2 includes the right short side SE2 and the right parts of the upper long side LE1 and the lower long side LE2.

Please refer to FIG. 1 again. Generally speaking, these unidirectional magnetoresistive sensors 120 are arranged beside the magnetic flux concentrator 110. According to different installation positions, these unidirectional magnetoresistive sensors 120 can be divided into a plurality of first and second unidirectional magnetoresistive sensors 1201 and 1202. In detail, the first unidirectional magnetoresistive sensors 1201 are arranged beside the first end EP1, and according to the different installation positions, the first unidirectional magnetoresistive sensors 1201 are further divided into first , The third part P1, P3, where the first and third parts P1, P3 are separately arranged on opposite sides (upper and lower sides) of the first end EP1, and are separately arranged on the upper part of the first end EP1 Next to the long side LE1 and the lower long side LE2. Similarly, these second unidirectional magnetoresistive sensors 1202 are arranged beside the second end EP2, and according to the different installation positions, these second unidirectional magnetoresistive sensors 1202 are further divided into second , The fourth part P2, P4, where the second and fourth parts P2, P4 are separately arranged on opposite sides (upper and lower sides) of the second end EP2, and are separately arranged on the upper part of the second end EP2 Next to the long side LE1 and the lower long side LE2.

Please refer to Figure 1 again. In this embodiment, the first and third parts P1 and P3 are coupled to form the first Wheatstone with the full bridge FWH1, and the second and fourth parts P2 and P4 are Coupled to the second Huisi full bridge FWH2. In other words, the first and second unidirectional magnetoresistive sensors 1201 and 1202 located beside different ends EP1 and EP2 are respectively coupled to form two Wheatstone full bridges FWH1 and FWH2. The calculator 130 is coupled to the first and second wheat-side full bridges FWH1 and FWH2, and is used to receive electrical signals from the first and second wheat-side full bridges FWH1 and FWH2.

After describing the configuration of the above-mentioned components, in the following paragraphs, how the magnetic field sensing device 100 measures the magnetic field components in different directions will be described in detail.

4A to 4C are schematic diagrams of external magnetic fields placed in different directions by the magnetic field sensing device in FIG. 1.

Referring to FIG. 2A and 4A, when a magnetic field sensing device 100 is placed in the magnetic field direction is the direction D1 _D1 external magnetic fields H, the external magnetic fields H _D1 because of the influence of the flux concentrators 110 changes its direction. In other words, the magnetic field direction of the external magnetic field H _D1 will be transformed from the original direction D1 to a magnetic field in the direction D2 or in the opposite direction to the direction D2 (the transformed magnetic field is denoted as H'), and a single direction at a different position The magnetoresistive sensor 120 will have different resistance changes due to different magnetic field directions.

In detail, the first and fourth parts P1 and P4 (upper left and lower right parts) will sense the magnetic field component in the direction opposite to the direction D2 due to the relationship between the magnetic flux concentrator 110, and the unidirectional magnetic The pinning direction E1 of the resistive sensor 120 is the direction D2. Therefore, the first and second unidirectional magnetoresistive sensors 1201 and 1202 in the first and fourth parts P1 and P4 are due to the "transformed external magnetic field H The two directions of the “magnetic field direction of _D1 ” and the “pinning direction E1” are anti-parallel to each other, resulting in a positive △R change in the resistance value, where △R is greater than 0.

Conversely, the second and third parts P2 and P3 (upper right and lower left parts) will sense the magnetic field component in the direction D2 due to the relationship between the magnetic flux concentrator 110, and the nail of the unidirectional magnetoresistive sensor 120 The piercing direction E1 is the direction D2. Therefore, the first and second unidirectional magnetoresistive sensors 1201 and 1202 in the second and third parts P2 and P3 will be affected by the "transformed magnetic field direction of the external magnetic field H _D1 " The two directions of the "pinning direction E1" are parallel to each other, resulting in a negative △R change in its resistance, where △R is greater than 0.

Therefore, since the resistance changes of the first and third parts P1 and P3 in the first and third parts of the full bridge FWH1 (the resistance value of the first part P1 is positive, the resistance value of the third part P3 is negative) and the second The resistance changes of the second and fourth parts P2 and P4 in the full bridge FWH2 (the resistance change of the second part P2 is negative, and the resistance change of the third part P3 is positive) are opposite to each other, so the first, The signal directions of the first and second electrical signals respectively output by the second wheat and full bridges FWH1 and FWH2 are opposite to each other. The calculator 130 performs a subtraction operation based on the first and second electrical signals, and determines the magnitude and the positive or negative value of the external magnetic field H _D1 in the direction D1 according to the result of the subtraction operation.

2B and 4B at the same time, when the magnetic field sensing device 100 is placed in the external magnetic field _HD2 with the direction of the magnetic field in the direction D2, generally speaking, the external magnetic field _HD2 is not likely to be affected by the magnetic flux concentrator 110. Change its direction. Accordingly, the first to the fourth portion of the first, second single direction of the magnetoresistive sensor pinning directions P1 ~ P4 of the 1201, 1202 and two mutually E1 direction of external magnetic fields H _D2 in parallel, each resulting The resistance value of the unidirectional magnetoresistive sensor 120 has a negative ΔR change, where ΔR is greater than zero.

Therefore, since the resistance changes of the magnetoresistive sensors 120 used to form the two Wyss and full bridges FWH1 and FWH2 are the same, that is, between the two voltage output terminals of each Wyss and full bridges FWH1 and FWH2 the measured voltage difference signal is zero, the magnitude of external magnetic fields H _D2 is not a first, a second full-bridge benefits Division and FWH1, FWH2 architecture sensed.

Referring to FIG. 2C and 4C, the magnetic field sensing device when placed in a magnetic field direction 100 is the direction D3 _D3 external magnetic fields H, the external magnetic fields H _D3 because affect flux concentrators 110 and its direction. In other words, the magnetic field direction of the external magnetic field _HD3 will be changed from the original direction D2 to a magnetic field in the direction D2 or in the opposite direction to the direction D2, while the unidirectional magnetoresistive sensors 120 located at different positions will be different The direction of the magnetic field will have different resistance changes.

In detail, the first and second parts P1 and P2 (upper left and upper right parts) will sense the magnetic field component in the opposite direction of the direction D2 due to the relationship between the magnetic flux concentrator 110, and the unidirectional magnetic resistance The pinning direction E1 of the sensor 120 is the direction D2, so the first and second unidirectional magnetoresistive sensors 1201 and 1202 in the first and second parts P1 and P2 are due to the "transformed external magnetic field H _D3 The two directions of the "magnetic field direction" and the "pinning direction E1" are anti-parallel to each other, resulting in a positive △R change in the resistance value, where △R is greater than 0.

Please refer to Figure 4C and compare to Figure 2C. On the contrary, the third and fourth parts P3 and P4 (bottom left and bottom right parts) will sense the magnetic field component in the direction D2 due to the relationship of the magnetic flux concentrator 110, and , The pinning direction E1 of the unidirectional magnetoresistive sensor 120 is the direction D2, so the first and second unidirectional magnetoresistive sensors 1201 and 1202 in the third and fourth parts P3 and P4 will be The direction of the transformed external magnetic field _HD3 and the "pinning direction E1" are parallel to each other, resulting in a negative △R change in its resistance, where △R is greater than 0.

Therefore, since the resistance changes of the first and third parts P1 and P3 in the first and third parts of the full bridge FWH1 (the resistance value of the first part P1 is positive, the resistance value of the third part P3 is negative) and the second The resistance changes of the second and fourth parts P2 and P4 in the same full bridge FWH2 (the resistance change of the second part P2 is positive and the resistance change of the fourth part P4 is negative) are the same as each other, so the first and second The signal directions of the first and second electrical signals respectively output by the Wyeth and full bridges FWH1 and FWH2 are the same. The calculator 130 performs addition operations based on the first and second electrical signals, and determines the magnitude and the positive and negative values of the external magnetic field _HD3 in the direction D3 based on the addition results.

In view of the above, in the magnetic field sensing device 100 of this embodiment, since the pinning directions E1 of the unidirectional magnetoresistive sensors 120 are all designed to be the same direction, the manufacturing process is simple, the cost is low, and the stability is good. Sex. In addition, the magnetic field sensing device 100 arranges the unidirectional magnetoresistive sensors 120 at the opposite ends EP1 and EP2 of the magnetic flux concentrator 110 to form two Wheatstone full bridges FWH1 and FWH2 respectively. The electrical signals output by the Wyss and full bridges FWH1 and FWH2 due to the influence of the external magnetic field are used to achieve multi-axis sensing (for example, two-axis sensing, which can determine the magnetic field components of the external magnetic field in two different directions D1 and D3). Since the circuit architectures of the first and second Huis are the same as the full bridge FWH1 and FWH2, they are distributed in the corresponding end EP1 and EP2 areas Therefore, its circuit architecture is relatively simple and not complicated, which can effectively reduce manufacturing costs.

It must be noted here that the following embodiments follow part of the content of the foregoing embodiments, and the description of the same technical content is omitted. For the same component names, reference may be made to part of the foregoing embodiments, and the following embodiments will not be repeated. In addition, in order to clearly show the drawing, the reference numerals of the parts that are the same as those in the previous embodiment are omitted in the drawings described in the following paragraphs.

5A to 7A are schematic top views of magnetic field sensing devices in different embodiments of the present invention in a first time interval. 5B to 7B are schematic top views of the magnetic field sensing device of FIGS. 5A and 7A in a second time interval, respectively. FIG. 8 is a schematic top view of a magnetic field sensing device according to another embodiment of the invention.

Please refer to FIG. 5A. The magnetic field sensing device 100a of FIG. 5A is substantially similar to the magnetic field sensing device 100 of FIG. 1. The main difference is that the magnetic field sensing device 100a further includes a time-sharing switching circuit 140, wherein the time-sharing switching circuit 140 It is coupled to the unidirectional magnetoresistive sensors 120 and used to switch at least a part of the contacts between the unidirectional magnetoresistive sensors 120 to change the circuit connection between the magnetoresistive sensors 120 , To form another Huisi full bridge with a different architecture from the first and second Wisi full bridges FWH1 and FWH2. In this embodiment, the magnetoresistive sensors 120 further include a plurality of third unidirectional magnetoresistive sensors 1203. In this embodiment, these third unidirectional magnetoresistive sensors 1203 overlap the middle part MP.

In this embodiment, the magnetic field sensing device 100a can switch the circuit connection between the unidirectional magnetoresistive sensors 120 in different time intervals through the time-sharing switching circuit 140, and the direction D1 can be measured. ~D3's magnetic field component. In other words, the actual The magnetic field sensing device 100a of the embodiment can realize three-axis sensing. In the following paragraphs, how the magnetic field sensing device 100a measures the magnetic field components of the directions D1 to D3 will be described in sections.

Referring to FIG. 5A, in the first time interval, the time-sharing switching circuit 140 forms the first and second unidirectional magnetoresistive sensors 1201 and 1202 into two wheat-same full bridges FWH1 and FWH2, respectively, and the measurement direction The magnetic field components of D1 and D3. The principle of the magnetic field sensing device 100a for measuring the magnetic field components in the directions D1 and D3 is substantially similar to that of the magnetic field sensing device 100 of FIG. 1, and will not be repeated here.

Referring to FIG. 5B, in the second time interval, the time-sharing switching circuit 140 may select at least a part of the unidirectional magnetoresistive sensors 120 from the first to fourth parts P1 to P4 and interact with these third unidirectional magnetoresistive sensors. The sensor 1203 is coupled to the third Wyeth full bridge FWH3. For example, the time-sharing switching circuit 140 selects the two first unidirectional magnetoresistive sensors 1201 closest to the third unidirectional magnetoresistive sensor 1203 in the first and third parts P1 and P3 for coupling. Full bridge action.

Please refer to FIG. 5B and compare to FIG. 2B, when the magnetic field sensing device 100a is placed in the external magnetic field HD2 with the magnetic field direction _D2 , since the third unidirectional magnetoresistive sensor 1203 is shielded by the magnetic flux concentrator 110, Instead of sensing the external magnetic field _HD2 , the two first unidirectional magnetoresistive sensors 1201 have negative ΔR changes due to the influence of the external magnetic field _HD2 . Thus, when the third full bridge FWH3 benefits Division and influence of external magnetic field by H _D2, the third single-direction of the magnetoresistive sensor resistance value of 1203 is not changed, and this two unidirectional first magnetoresistive sensor The resistance value of 1201a produces a negative △R change, so the voltage difference signal measured between the two voltage output terminals in the third Wyeth and full bridge FWH3 (ie the third electrical signal) is a non-zero electrical signal That is, the size of external magnetic fields H _D2 may be a third benefit of the Division with a sense of the full-bridge architecture FWH3 sensed. The calculator 130 then determines the magnitude and the positive or negative value of the external magnetic field _HD2 in the direction D2 according to the third electrical signal.

In view of the above, in other embodiments, the time-sharing switching circuit 140 can also select other first and second unidirectional magnetoresistive sensors 1201 and 1202 and couple with these third unidirectional magnetoresistive sensors 1203. Connected to the third Wyeth and full bridge FWH3, the present invention is not limited to this.

Please refer to FIG. 6A. The magnetic field sensing device 100b of FIG. 6A is substantially similar to the magnetic field sensing device 100a of FIG. 5A. The main difference is that in the magnetic field sensing device 100b, depending on the position of the third unidirectional The magnetoresistive sensor 1203 can be divided into fifth and sixth parts P5 and P6. The sixth part P6 includes two sixth sub-parts SP6. The fifth part P5 is arranged to overlap the middle part MP, and the two sixth sub-parts SP6 are respectively arranged beside the opposite sides (upper and lower sides) of the middle part MP without overlapping with the middle part MP.

Referring to FIG. 6A, in the first time interval, the time-sharing switching circuit 140 forms the first and second unidirectional magnetoresistive sensors 1201 and 1202 into two wheat-same full bridges FWH1 and FWH2, respectively, and the measurement direction The magnetic field components of D1 and D3. The principle of the magnetic field sensing device 100a for measuring the magnetic field components in the directions D1 and D3 is substantially similar to that of the magnetic field sensing device 100 of FIG. 1, and will not be repeated here.

Referring to FIG. 6B, in the second time interval, the time-sharing switching circuit 140 couples the fifth and sixth parts P5 and P6 into the third wheat-to-full bridge FWH3b. Based on the principle of magnetic field sensing apparatus 100a 5B is similar to FIG, when the third full bridge FWH3b benefits Division and influence of external magnetic field by H _D2, the third part of the same benefits of a full bridge FWH3b Division third single direction of magnetic sixth portion P6 resistive sensors 1203 because of external magnetic fields H _D2 and the resistance value is changed, and the fifth portion P5 belongs is NO, the third full bridge FWH3b benefits Division and may output a non-zero third electrical signal. The calculator 130 then determines the magnitude and the positive or negative value of the external magnetic field _HD2 in the direction D2 according to the third electrical signal.

Please refer to FIG. 7A. The magnetic field sensing device 100c of FIG. 7A is substantially similar to the magnetic field sensing device 100b of FIG. 6A. The main difference is that the third unidirectional magnetoresistive sensors 1203 are arranged at different positions. In detail, these third unidirectional magnetoresistive sensors 1203 include fifth and sixth parts P5c and P6c. The fifth part P5c is arranged beside the short side (ie, the left short side SE1) belonging to the first end EP1 and does not overlap with the first end EP1, and the sixth part P6c is arranged on the short side belonging to the second end EP2 (Ie, the right short side SE2) and not overlapped with the second end EP2.

Referring to FIG. 7A, in the first time interval, the time-sharing switching circuit 140 forms the first and second unidirectional magnetoresistive sensors 1201 and 1202 into two wheat-same full bridges FWH1 and FWH2, respectively, and the measurement direction The magnetic field components of D1 and D3. The principle of the magnetic field sensing device 100c for measuring the magnetic field components in the directions D1 and D3 is substantially similar to that of the magnetic field sensing device 100 of FIG. 1, and will not be repeated here.

Referring to FIG. 7B, in the second time interval, the time-sharing switching circuit 140 couples the fifth and sixth parts P5c and P6c into a third Wysh and full bridge FWH3c. Please reference to Figure 2B, when the third full bridge FWH3c benefits Division and influence of external magnetic field by H _D2, the fifth, sixth portion P5c, external magnetic fields H _D2 at P6c is where the magnetic flux concentrator 110 fallout The direction of the magnetic field changes to the direction D1. Therefore, the unidirectional third magnetoresistive sensor 1203 senses the magnetic field in the direction D1 due to the relationship of the magnetic flux concentrator 110, and its resistance can be changed. Therefore, the third whistle and full bridge FWH3c can output a non-zero third electrical signal. The calculator 130 then determines the magnitude and the positive or negative value of the external magnetic field _HD2 in the direction D2 according to the third electrical signal.

Please refer to FIG. 8. The magnetic field sensing device 100d of FIG. 8 is substantially similar to the magnetic field sensing device 100 of FIG. 1. The main difference is that the magnetic field sensing device 100d further includes a unidirectional magnetic field sensing element 150, which is similar to a computer 130 Coupled. In the above description, the first and second Wheatstone full bridges FWH1 and FWH2 formed by the unidirectional magnetoresistive sensors 120 are used to measure the magnetic field components in the directions D1 and D3, while the unidirectional magnetic field sensing The element 150 is used to measure the magnetic field component in the direction D2, so that the magnetic field sensing device 100d of this embodiment realizes three-axis sensing. In other words, the unidirectional magnetic field sensing element 150 can be affected by the external magnetic field to output an electrical signal (that is, the third electrical signal), and the calculator 130 can determine the direction D2 according to the electrical signal output by the unidirectional magnetic field sensing element 150 The magnetic field component on the Those who are familiar with the art can use various magnetoresistive sensors to construct a unidirectional magnetic field sensing element 150 that can measure the magnetic field component in the direction D2. The present invention is not limited to this. .

In summary, in the magnetic field sensing device of the embodiment of the present invention, since the pinning directions of the unidirectional magnetoresistive sensors are all in the same direction, the manufacturing process is simple, the cost is low, and the stability is good. . In addition, the magnetic field sensing device arranges these unidirectional magnetoresistive sensors at the opposite ends of the magnetic flux concentrator to form two Huisi full bridges respectively, and the two Huisi full bridges are due to the external magnetic field. Affected and output electrical signals to achieve multi-axis sensing, the circuit structure is relatively simple and not complicated Can effectively reduce manufacturing costs.

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 slight changes and modifications without departing from the spirit and scope of the present invention. The scope of protection of the present invention shall be determined by the scope of the attached patent application.

100‧‧‧Magnetic field sensing device

110‧‧‧Flux Concentrator

120‧‧‧Single Direction Magnetoresistive Sensor

1201~1202‧‧‧The first and second unidirectional magnetoresistive sensors

130‧‧‧Calculator

C1~C8‧‧‧Contact

D1~D3‧‧‧direction

E1‧‧‧Pinning direction

E2‧‧‧Easy magnetization axis

EP1‧‧‧First end

EP2‧‧‧Second end

LE‧‧‧long side

LE1‧‧‧Upper long side

LE2‧‧‧Bottom long side

MP‧‧‧Middle

P1‧‧‧Part One

P2‧‧‧Part Two

P3‧‧‧Part Three

P4‧‧‧Part Four

FWH1‧‧‧First Huisi Tongquan Bridge

FWH2‧‧‧The Second Huisi Tongquan Bridge

S‧‧‧Substrate

SE‧‧‧Short side

SE1‧‧‧Left short edge

SE2‧‧‧Right short side

Claims (8)

A magnetic field sensing device, comprising: a magnetic flux concentrator having opposite first and second ends; a plurality of unidirectional magnetoresistive sensors with the same pinning direction, and the unidirectional magnetoresistive sensors The sensor is arranged beside the magnetic flux concentrator, and the unidirectional magnetoresistive sensors further include a plurality of first unidirectional magnetoresistive sensors and a plurality of second unidirectional magnetoresistive sensors, wherein the The first unidirectional magnetoresistive sensors are disposed beside the first end, and the first unidirectional magnetoresistive sensors further include a first part and a third part respectively disposed on opposite sides of the first end. Part, and the first part and the third part are coupled to form a first Wheatstone full bridge, the second unidirectional magnetoresistive sensors are arranged beside the second end, and the second unidirectional magnetoresistive The sensor further includes a second part and a fourth part respectively disposed on opposite sides of the second end, and the second part and the fourth part are coupled to form a second whole bridge; a calculator, coupled In the magnetoresistive sensors, the first Wheatstone full bridge is affected by an external magnetic field and outputs a first electrical signal, and the second Wheatstone full bridge is affected by the external magnetic field and outputs a second electrical signal , The calculator determines the magnetic field components of the external magnetic field in two different directions according to the first electrical signal and the second electrical signal, wherein the magnetoresistive sensors further include a plurality of third unidirectional magnetoresistive sensors The third unidirectional magnetoresistive sensors are arranged beside the magnetic flux concentrator, The magnetic flux concentrator further includes an intermediate portion located between the first end portion and the second end portion, and connected to the first end portion and the second end portion, wherein the third unidirectional At least a part of the magnetoresistive sensor overlaps the middle part, and the time-sharing switching circuit is coupled to the magnetoresistive sensors. In the first time interval, the time-sharing switching circuit connects the first part with The third part is coupled to form the first wheat-to-full bridge, and the second part and the fourth part to be coupled to the second wheat-to-full bridge, so that the calculator is based on the first electrical signal and the The second electrical signal determines the magnetic field components of the external magnetic field in the two different directions. The magnetic field sensing device according to claim 1, wherein, in the second time interval, the time-sharing switching circuit is selected from the first part, the second part, the third part, and the fourth part At least a part of the unidirectional magnetoresistive sensors and the third unidirectional magnetoresistive sensors are coupled to form a third whistle full bridge, and the third whistle full bridge is affected by the external magnetic field and outputs a third telecommunication According to the third electrical signal, the calculator determines the magnetic field component of the external magnetic field in another direction, wherein the magnetic field component in the other direction is different from the magnetic field components in the two different directions. The magnetic field sensing device according to claim 1, wherein the third unidirectional magnetoresistive sensors further include a fifth part and a sixth part, the fifth part and the middle part are overlapped, and The sixth part further includes two sixth sub-parts, and the two sixth sub-parts are respectively disposed on opposite sides of the middle part and not overlapped with the middle part. According to the magnetic field sensing device described in item 1 of the scope of patent application, in the second time interval, the time-sharing switching circuit couples the fifth part and the sixth part to form a third Huisi full bridge, the The third Huisi full bridge outputs a third electrical signal according to the external magnetic field. The calculator determines the magnetic field component of the external magnetic field in another direction according to the third electrical signal, wherein the magnetic field component in the other direction is different from The two magnetic field components in different directions. The magnetic field sensing device according to claim 1, wherein the magnetoresistive sensors further include a plurality of third unidirectional magnetoresistive sensors, and the third unidirectional magnetoresistive sensors are arranged Beside the magnetic flux concentrator and include a fifth part and a sixth part, the magnetic flux concentrator has two short sides and two long sides, any one of the two short sides is connected to the two long sides, and the first The end and the second end respectively include a part of the two long sides and one of the two short sides, wherein the first part and the third part are respectively disposed on the two long sides belonging to the first end The second part and the fourth part are respectively disposed beside the two long sides belonging to the second end part, and the fifth part is disposed beside the short side part belonging to the first end part and not connected to the first end part. The ends are overlapped, and the sixth part is disposed beside the short side belonging to the second end and not overlapped with the second end. According to the magnetic field sensing device described in item 5 of the scope of patent application, wherein, in the second time interval, the time-sharing switching circuit couples the fifth part and the sixth part to form a third Huisi full bridge, the The third Huisi full bridge outputs a third electrical signal according to the external magnetic field. The calculator determines the magnetic field component of the external magnetic field in another direction according to the third electrical signal, wherein the magnetic field component in the other direction is different from The two magnetic field components in different directions. The magnetic field sensing device described in claim 1 further includes a unidirectional magnetic field sensing element coupled to the calculator, wherein the unidirectional magnetic field sensing element is affected by the external magnetic field to output a third electrical signal According to the third electrical signal, the calculator determines the magnetic field component of the external magnetic field in another direction, wherein the magnetic field component in the other direction is different from the magnetic field components in the two different directions. According to the magnetic field sensing device described in item 1 of the scope of patent application, the types of the unidirectional magnetoresistive sensor include giant magnetoresistive sensors or tunneling magnetoresistive sensors.

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