阅读说明：本技术 磁场感测装置 (Magnetic field sensing device ) 是由 袁辅德 赖孟煌 于 2019-07-30 设计创作，主要内容包括：本发明提供一种磁场感测装置,包括磁通集中器以及多个单方向磁阻传感器。磁通集中器具有相对的第一、第二端部。这些单方向磁阻传感器具有相同的钉扎方向且设置于磁通集中器旁。这些单方向磁阻传感器还包括多个第一、第二单方向磁阻传感器。这些第一单方向磁阻传感器设置于第一端部旁,且还包括分别设置于第一端部相对两侧的第一、第三部分。第一、第三部分耦接成第一惠司同全桥。这些第二单方向磁阻传感器设置于第二端部旁,且还包括分别设置于第二端部相对两侧的第二、第四部分。第二、第四部分耦接成第二惠司同全桥。(The invention provides a magnetic field sensing device which comprises a magnetic flux concentrator and a plurality of one-way magnetoresistive sensors. The flux concentrator has opposing first and second ends. The unidirectional magnetoresistive sensors have the same pinning direction and are arranged beside the magnetic flux concentrator. The single direction magnetic resistance sensors also comprise a plurality of first and second single direction magnetic resistance sensors. The first one-way magnetic resistance sensors are arranged beside the first end part and also comprise a first part and a third part which are respectively arranged at two opposite sides of the first end part. The first and third portions are coupled to form a first Whitserving bridge. The second one-way magnetoresistive sensors are arranged beside the second end part and also comprise a second part and a fourth part which are respectively arranged at two opposite sides of the second end part. The second and fourth sections are coupled to form a second Wheatstone bridge.)

1. A magnetic field sensing device comprising:

a flux concentrator having opposing first and second ends;

a plurality of unidirectional magnetoresistive sensors having the same pinning direction, the plurality of unidirectional magnetoresistive sensors being disposed beside the magnetic flux concentrator, and the plurality of unidirectional magnetoresistive sensors further including a plurality of first unidirectional magnetoresistive sensors and a plurality of second unidirectional magnetoresistive sensors,

wherein the content of the first and second substances,

the first unidirectional magnetoresistive sensors are arranged beside the first end part, the first unidirectional magnetoresistive sensors also comprise a first part and a third part which are respectively arranged at two 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 plurality of second one-way magnetoresistive sensors are arranged beside the second end part, and further comprise a second part and a fourth part which are respectively arranged on two opposite sides of the second end part, and the second part and the fourth part are coupled to form a second Wheatstone full bridge.

2. The magnetic field sensing device according to claim 1, further comprising a calculator coupled to the plurality of magnetoresistive sensors,

wherein the content of the first and second substances,

the first Wheatstone bridge is influenced by an external magnetic field to output a first electric signal, the second Wheatstone bridge is influenced by the external magnetic field to output a second electric signal, and the calculator determines magnetic field components of the external magnetic field in two different directions according to the first electric signal and the second electric signal.

3. The magnetic field sensing device of claim 2, wherein the plurality of magnetoresistive sensors further comprises a third plurality of unidirectional magnetoresistive sensors disposed adjacent to the flux concentrator,

the magnetic flux concentrator further comprising a middle portion located between and connected to the first and second end portions,

wherein at least a portion of the plurality of third unidirectional magnetoresistive sensors is disposed overlapping the middle portion.

4. The magnetic field sensing device according to claim 3, further comprising a time-shared switching circuit coupled to the plurality of magnetoresistive sensors,

wherein the content of the first and second substances,

in a first time interval, the time-sharing switching circuit couples the first portion and the third portion into the first Wheatstone full bridge and couples the second portion and the fourth portion into the second Wheatstone full bridge, so that the calculator determines 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 a second time interval, the time-sharing switching circuit selects at least one part of one-way magnetoresistive sensors from the first part, the second part, the third part and the fourth part and couples the one-way magnetoresistive sensors with the third one-way magnetoresistive sensors to form a third Wheatstone co-full bridge, the third Wheatstone co-full bridge is influenced by the external magnetic field and outputs a third electric signal, and the calculator determines a magnetic field component of the external magnetic field in another direction according to the third electric signal, wherein the magnetic field component in the another direction is different from the magnetic field components in the two different directions.

5. The magnetic field sensing device according to claim 3,

the plurality of third unidirectional magnetoresistive sensors further includes a fifth portion and a sixth portion,

the fifth portion is disposed to overlap the middle portion, and the sixth portion further includes two sixth sub-portions respectively disposed on opposite sides of the middle portion and not disposed to overlap the middle portion.

6. The magnetic field sensing device according to claim 5, further comprising a time-shared switching circuit coupled to the plurality of magnetoresistive sensors,

wherein the content of the first and second substances,

in a first time interval, the time-sharing switching circuit couples the first portion and the third portion into the first Wheatstone full bridge and couples the second portion and the fourth portion into the second Wheatstone full bridge, so that the calculator determines 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 a second time interval, the time-sharing switching circuit couples the fifth part and the sixth part into a third Wheatstone full bridge, the third Wheatstone full bridge outputs a third electric signal according to the external magnetic field, and the calculator determines a magnetic field component of the external magnetic field in another direction according to the third electric signal, wherein the magnetic field component in the other direction is different from the magnetic field components in the two different directions.

7. The magnetic field sensing device of claim 2,

the plurality of magnetoresistive sensors further includes a plurality of third unidirectional magnetoresistive sensors disposed adjacent to the magnetic flux concentrator and including a fifth portion and a sixth portion,

the magnetic flux concentrator has two short sides and two long sides, any one of the two short sides is connected with the two long sides, the first end portion and the second end portion respectively comprise a part of the two long sides and one of the two short sides,

wherein the content of the first and second substances,

the first part and the third part are respectively arranged beside the two long sides belonging to the first end part,

the second part and the fourth part are respectively arranged beside the two long sides belonging to the second end part,

the fifth portion is provided beside the short side belonging to the first end portion and is not provided to overlap with the first end portion,

the sixth portion is provided beside the short side belonging to the second end portion and is not overlapped with the second end portion.

8. The magnetic field sensing device according to claim 7, further comprising a time-shared switching circuit coupled to the plurality of magnetoresistive sensors,

wherein the content of the first and second substances,

in a first time interval, the time-sharing switching circuit couples the first portion and the third portion into the first Wheatstone full bridge and couples the second portion and the fourth portion into the second Wheatstone full bridge, so that the calculator determines 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 a second time interval, the time-sharing switching circuit couples the fifth part and the sixth part into a third Wheatstone full bridge, the third Wheatstone full bridge outputs a third electric signal according to the external magnetic field, and the calculator determines a magnetic field component of the external magnetic field in another direction according to the third electric signal, wherein the magnetic field component in the other direction is different from the magnetic field components in the two different directions.

9. The magnetic field sensing device according to claim 2, further comprising a unidirectional magnetic field sensing element coupled to the calculator, wherein the unidirectional magnetic field sensing element is influenced by the external magnetic field to output a third electrical signal, and the calculator determines a magnetic field component of the external magnetic field in another direction according to the third electrical signal, wherein the magnetic field component in the another direction is different from the magnetic field components in the two different directions.

10. The magnetic field sensing device according to claim 1, wherein the kind of the unidirectional magnetoresistive sensor comprises a giant magnetoresistive sensor or a tunneling magnetoresistive sensor.

Technical Field

The present invention relates to a magnetic field sensing device.

Background

With the development of science and technology, electronic products with navigation and positioning functions are becoming more and more diversified. Electronic compasses provide functionality comparable to conventional compasses in the fields of automotive navigation, aviation, and personal hand-held device applications. 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, a Giant Magnetoresistive (GMR) multilayer structure or a Tunneling Magnetoresistive (TMR) multilayer structure is generally configured as a wheatstone full bridge, and two pinning directions (pinning directions) that are antiparallel to each other are designed for the pinning directions of the GMR multilayer structures. For example, to achieve three-axis sensing, six pinning directions are required, two by two of which are anti-parallel to each other. However, designing different pinning directions for antiferromagnetic layers (antiferromagnetic layers) on a wafer can cause manufacturing difficulties, additional costs, and reduced pinning layer stability.

Disclosure of Invention

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

In an embodiment of the present invention, a magnetic field sensing apparatus includes a magnetic flux concentrator and a plurality of unidirectional magnetoresistive sensors. The flux concentrator has opposite first and second ends. These unidirectional magnetoresistive sensors have the same pinning direction. These unidirectional magnetoresistive sensors are disposed beside the flux concentrator. The single direction magnetoresistive sensors further include a plurality of first single direction magnetoresistive sensors and a plurality of second single direction magnetoresistive sensors. The first one-way magnetic resistance sensors are arranged beside the first end part, and the first one-way magnetic resistance sensors further comprise a first part and a third part which are respectively arranged at two opposite sides of the first end part. The first portion and the third portion are coupled to form a first wheatstone full bridge. The second one-way magnetic resistance sensors are arranged beside the second end parts. The second unidirectional second magnetoresistive sensors further include a second portion and a fourth portion respectively disposed on opposite sides of the second end portion, and the second portion and the fourth portion are coupled to form a second wheatstone common full bridge.

In an embodiment of the invention, the magnetic field sensing apparatus further includes a calculator coupled to the magnetoresistive sensors. The first Wheatstone bridge outputs a first electrical signal under the influence of an external magnetic field. The second Wheatstone bridge is influenced by the external magnetic field and outputs a second electric signal. The calculator determines magnetic field components of the external magnetic field in two different directions according to the first electric signal and the second electric signal.

In an embodiment of the invention, the plurality of magnetoresistive sensors further includes a plurality of third unidirectional magnetoresistive sensors. These third unidirectional magnetoresistive sensors are disposed next to the flux concentrator. The flux concentrator also includes an intermediate portion. The middle portion is located between the first end portion and the second end portion and connected with the first end portion and the second end portion. At least a part of the third one-way magnetoresistive sensors is disposed to overlap the intermediate portion.

In an embodiment of the invention, the magnetic field sensing apparatus further includes a time-sharing switching circuit coupled to the magnetoresistive sensors. In the first time interval, the time-sharing switching circuit couples the first part and the third part into a first Wheatstone-like full bridge, and couples the second part and the fourth part into a second Wheatstone-like full bridge, so that the calculator determines the magnetic field components of the external magnetic field in the two different directions according to the first electric signal and the second electric signal. In a second time interval, the time-sharing switching circuit selects at least one part of the one-way magnetoresistive sensors from the first part, the second part, the third part and the fourth part and couples the one-way magnetoresistive sensors with the third one-way magnetoresistive sensors to form a third Wheatstone full bridge. The third Wheatstone bridge is influenced by the external magnetic field and outputs a third electric signal. The calculator determines a magnetic field component of the external magnetic field in another direction according to the third electric 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 invention, the third unidirectional magnetoresistive sensors further include a fifth part and a sixth part. The fifth portion is disposed in overlapping relation with the intermediate portion, and the sixth portion further includes two sixth sub-portions. The two sixth sub-portions are respectively arranged on two opposite sides of the middle portion and are not overlapped with the middle portion.

In an embodiment of the invention, the magnetic field sensing apparatus further includes a time-sharing switching circuit coupled to the magnetoresistive sensors. In the first time interval, the time-sharing switching circuit couples the first part and the third part into a first Wheatstone-like full bridge, and couples the second part and the fourth part into a second Wheatstone-like full bridge, so that the calculator determines the magnetic field components of the external magnetic field in two different directions according to the first electric signal and the second electric signal. In a second time interval, the time-sharing switching circuit selects at least one part of the one-way magnetoresistive sensors from the first part, the second part, the third part and the fourth part and couples the one-way magnetoresistive sensors with the third one-way magnetoresistive sensors to form a third Wheatstone full bridge. The third Wheatstone bridge is influenced by the external magnetic field and outputs a third electric signal. The calculator determines a magnetic field component of the external magnetic field in another direction based on 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 invention, the plurality of magnetoresistive sensors further includes a plurality of third unidirectional magnetoresistive sensors. The third one-way magnetoresistive sensors are disposed beside the flux concentrator and include a fifth portion and a sixth portion. The flux concentrator has two short sides and two long sides. Any one of the two short sides is connected with the two long sides. The first end portion and the second end portion respectively comprise one of a part of the two long sides and one of the two short sides. The first part and the third part are respectively arranged beside the two long sides belonging to the first end part. The second part and the fourth part are respectively arranged beside the two long sides belonging to the second end part. The fifth portion is disposed beside the short side belonging to the first end portion and is not overlapped with the first end portion. The sixth part is arranged beside the short side belonging to the second end part and is not overlapped with the second end part.

In an embodiment of the invention, the magnetic field sensing apparatus further includes a time-sharing switching circuit coupled to the magnetoresistive sensors. In the first time interval, the time-sharing switching circuit couples the first part and the third part into a first Wheatstone-like full bridge, and couples the second part and the fourth part into a second Wheatstone-like full bridge, so that the calculator determines the magnetic field components of the external magnetic field in the two different directions according to the first electric signal and the second electric signal. In the second time interval, the time-sharing switching circuit couples the fifth part and the sixth part into a third Wheatstone. The third Wheatstone bridge outputs a third electrical signal according to the external magnetic field. The calculator determines a magnetic field component of the external magnetic field in another direction according to the third electric 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 invention, the magnetic field sensing apparatus further includes a unidirectional magnetic field sensing element coupled to the calculator. The one-way magnetic field sensing element is influenced by the external magnetic field and outputs a third electric signal. The calculator determines a magnetic field component of the extraneous magnetic field in another direction based on 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 invention, the single-direction magnetoresistive sensor includes a giant magnetoresistive sensor or a tunneling magnetoresistive sensor.

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

In order to make the aforementioned and other features and advantages of the invention more comprehensible, embodiments accompanied with figures are described in detail below.

Drawings

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

fig. 2A, 2B and 2C are respectively magnetic field line simulation diagrams of external magnetic fields transformed by the flux concentrator when the external magnetic fields along different directions are applied to the magnetic field sensing apparatus of fig. 1;

FIG. 3A is a schematic perspective view of a multi-layer film structure of the one-way magnetoresistive sensor of FIG. 1;

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

FIG. 3C is a diagram illustrating the resistance change of the one-way MR sensor of FIG. 3A under the action of external magnetic fields in different directions and in the absence of the external magnetic field;

FIGS. 4A to 4C are schematic views illustrating the magnetic field sensing device of FIG. 1 disposed in different directions for external magnetic fields;

FIGS. 5A to 7A are schematic top views of a magnetic field sensing device according to various embodiments of the present invention during a first time interval;

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

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

Description of the reference numerals

100. 100a to 100 d: magnetic field sensing device

110: magnetic flux concentrator

120: unidirectional magnetoresistive sensor

122: pinning layer

124: pinned layer

126: spacer layer

128: free layer

1201: first unidirectional magnetoresistive sensor

1202: second one-way magnetoresistive sensor

1203: third unidirectional magnetoresistive sensor

130: calculator

140: time-sharing switching circuit

150: one-way magnetic field sensing element

C1-C12: contact point

D1-D3: direction of rotation

E1: pinning direction

E2: easy magnetization axis

EP 1: first end part

EP 2: second end portion

H、H_D1、H_D2、H_D3: external magnetic field

H': transformed external magnetic field

LE: long side

LE 1: upper long side

LE 2: lower long side

MP: intermediate section

P_X、P_Y、P_Z: position of

P1: the first part

P2: the second part

P3: third part

P4: fourth section

P5, P5 c: fifth part

P6, P6 c: sixth section

SP 6: sixth subsection

R: resistance (RC)

FWH 1: first Whitz is with full bridge

FWH 2: second Huisy same full bridge

FWH3, FWH3b, FWH3 c: third Huishi same full bridge

S: substrate

SD: sensing direction

And SE: short side

SE 1: left short side

SE 2: right short side

Detailed Description

For convenience of describing the configuration of the magnetic field sensing device according to the embodiment of the present invention, the magnetic field sensing device can be regarded as being located in a space formed by the directions D1, D2, and D3, and two of the directions D1, D2, and D3 are perpendicular to each other.

Fig. 1 is a schematic top view of a magnetic field sensing device according to an embodiment of the invention. Fig. 2A, 2B and 2C are respectively magnetic field line simulation diagrams of external magnetic fields transformed by the flux concentrator when the external magnetic fields along different directions are applied to the magnetic field sensing apparatus of fig. 1. Fig. 3A is a schematic perspective view of a 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 axis of magnetization of the free layer. FIG. 3C illustrates the resistance change of the one-way MR sensor of FIG. 3A under the action of external magnetic fields in different directions and in the absence of the external magnetic fields.

In the present embodiment, the magnetic field sensing device 100 includes a substrate S, a flux concentrator 110, a plurality of unidirectional magnetoresistive sensors 120, and a calculator 130. The above elements are described 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 an integrated-circuit (integrated-circuit), which is not limited in the present invention. In the present embodiment, the directions D1 and D2 are, for example, parallel to the surface of the substrate S, and the direction D3 is, for example, perpendicular to the surface of the substrate S.

In an embodiment of the present invention, the flux concentrator 110 refers to an element that is capable of concentrating the magnetic field lines of a magnetic field. The material of the flux concentrator 110 is, for example, a ferromagnetic material with high magnetic permeability, such as a nickel-iron alloy, cobalt-iron or cobalt-iron-boron alloy, ferrite, or other high magnetic permeability material, which is not limited by the invention. How extraneous magnetic fields of different directions are affected by the flux concentrator 110 is briefly described in the following paragraphs.

Referring to FIG. 2A, when an external magnetic field H along a direction D1 is applied_D1The position P of the one-way MR sensor 120 is determined by the magnetic flux concentrator 110_XThe magnetic field is converted into a magnetic field having a component in the direction D2 (i.e., parallel to the direction D2), so the magnetic field sensing apparatus 100 can determine the magnitude of the external magnetic field in the direction D1 by the unidirectional magnetic resistance sensor 120 sensing the magnitude of the external magnetic field in the direction D2.

Referring to FIG. 2B, when an external magnetic field H along the direction D2 is applied_D2The position P of the one-way magnetic resistance sensor 120 is influenced by the magnetic flux concentrator 110_YThe direction of the magnetic field at (a) is still maintained in a direction substantially parallel to direction D2 (i.e. parallel to direction D2).

Referring to FIG. 2C, when an external magnetic field H along the direction D3 is applied_D3When it is subjected to the action of the flux concentrator 110By the position P of the one-way magnetoresistive sensor 120_ZThe direction of the external magnetic field is changed to a magnetic field having a component of the direction D2, so the magnetic field sensing module 100 can determine the magnitude of the external magnetic field in the direction D3 by the unidirectional magnetic resistance sensor 120 sensing the magnitude of the magnetic field component in the direction D2 in the direction D2.

In the embodiment of the present invention, the unidirectional mr sensor 120 refers to a sensor whose resistance can be changed correspondingly by the change of the external magnetic field, and the types thereof include a giant mr sensor or a tunneling mr sensor. Referring to fig. 3A to 3C, in the present embodiment, the unidirectional magnetoresistive sensor 120 includes a pinned layer 122, a pinned layer 124, a spacer layer 126, and a free layer 128. The pinned layer 122 fixes the magnetization direction (magnetization direction) of the pinned layer 124, i.e., the pinning direction E1, and the easy axis E2 of the free layer 128 may be substantially perpendicular to the pinning direction E1. When the one-directional 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 one-directional magnetoresistive sensor 120 is a tunneling magnetoresistive sensor, the spacer layer 126 is made of an insulating material. It should be noted that, in the present embodiment, the "single direction" means that the pinning directions E1 of the magnetoresistive sensors are the same direction, which is, for example, the direction D2.

The graph in fig. 3C represents the variation 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 an external magnetic field H is applied to the unidirectional MR sensor 120 in the same direction as the pinning direction E1, the resistance R thereof decreases, i.e., the value of the resistance R corresponding to the black dots in the graph, wherein the pinning direction is the sensing direction SD of the unidirectional MR sensor 120. As shown in the lower left diagram of FIG. 3C, when the magnetic field H is applied to the one-directional MR sensor 120 in a direction opposite to the pinning direction E1, the resistance R increases, i.e., the value of the resistance R corresponding to the black dots in the graph. As shown in the upper right diagram of fig. 3C, when an external magnetic field H perpendicular to the pinning direction E1 is applied to the unidirectional magnetoresistive sensor 120, the resistance R thereof remains unchanged, i.e., the value of the resistance R corresponding to the black dots in the graph. As shown in the lower right of fig. 3C, when no magnetic field is applied to the one-way magnetoresistive sensor 120, the resistance R remains unchanged, i.e., the value of the resistance R corresponding to the black dots in the graph.

In the embodiment of the present invention, the calculator 130 generally refers to an element that receives the electrical signal and performs various mathematical operations on the electrical signal, such as addition, subtraction, multiplication, division, or a combination thereof, or performs other various mathematical operations, which is not limited by the invention.

After the functions of the above elements are briefly described, the arrangement relationship between the elements will be described in detail in the following paragraphs.

Referring to fig. 1, in the present embodiment, the flux concentrator 110 has first and second end portions EP1 and EP2 and a middle portion MP. The first end EP1 is opposite to the second end EP1, wherein the first end EP1 is for example a left end and the second end EP2 is for example a right end, but not limited thereto. Also, each end portion EP1, EP2 has opposite upper and lower sides. The middle portion MP is connected to the first and second end portions EP1, EP 2. More specifically, the flux concentrator 110 is, for example, a rectangle having 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. First end EP1 includes left short edge SE1 and the left portions of both sides of upper long edge LE1 and lower long edge LE 2. The second end EP2 includes a right short edge SE2 and right portions on either side of upper long edge LE1 and lower long edge LE 2.

Referring to fig. 1 again, generally, the one-way magnetoresistive sensors 120 are disposed beside the flux concentrator 110. Depending on the location, the unidirectional magnetoresistive sensors 120 can be divided into a plurality of first and second unidirectional magnetoresistive sensors 1201, 1202. In detail, the first unidirectional magnetoresistive sensors 1201 are disposed beside the first end EP1, and further according to different disposition positions, the first unidirectional magnetoresistive sensors 1201 are further divided into a first portion P1 and a third portion P3, wherein the first portion P1 and the third portion P3 are disposed beside an upper long side LE1 and a lower long side LE2 of the first end EP1, and are disposed beside the first end EP 1. Similarly, the second unidirectional magnetoresistive sensors 1202 are disposed beside the second end portion EP2, and further according to the different disposition positions, the second unidirectional magnetoresistive sensors 1202 are further divided into second and fourth portions P2 and P4, wherein the second and fourth portions P2 and P4 are disposed beside the upper long side LE1 and the lower long side LE2 of the second end portion EP2, respectively, and are disposed on opposite sides (upper and lower sides) of the second end portion EP 2.

Referring to fig. 1 again, in the present embodiment, the first and third portions P1 and P3 are coupled to form a first wheatstone full bridge FWH1, and the second and fourth portions P2 and P4 are coupled to form a second wheatstone full bridge FWH 2. That is, the first and second unidirectional magnetoresistive sensors 1201, 1202 located at different ends EP1, EP2 are coupled to two wheatstone full bridges FWH1, FWH2, respectively. The calculator 130 is coupled to the first and second wheatstone full bridges FWH1 and FWH2, and is configured to receive electrical signals from the first and second wheatstone full bridges FWH1 and FWH 2.

After the above configurations of the elements are described, the following paragraphs will describe how the magnetic field sensing apparatus 100 measures magnetic field components in different directions.

Fig. 4A to 4C are schematic views of the magnetic field sensing device in fig. 1 placed in different directions of external magnetic fields.

Referring to fig. 2A and fig. 4A, when the magnetic field sensing apparatus 100 is placed in the external magnetic field H with the magnetic field direction D1_D1Medium, external magnetic field H_D1Will be directed by the influence of the flux concentrator 110. That is, the external magnetic field H_D1The original direction D1 is transformed into a magnetic field in the direction D2 or in the direction opposite to the direction D2 (the transformed magnetic field is denoted as H'), and the unidirectional mr sensor 120 at different positions has different resistance variations due to different magnetic field directions.

In detail, the first and fourth portions P1 and P4 (upper left and lower right portions) sense a magnetic field component having a magnetic field direction opposite to the direction D2 due to the relationship of the magnetic flux concentrator 110, and the pinning direction E1 of the one-way magnetoresistive sensor 120 is the direction D2, so that the first and second portions P1 and P4 of the first and fourth portions P1 and P4 are respectively a single oneDirectional magnetoresistive sensors 1201, 1202 due to "transformed external magnetic field H_D1The magnetic field direction "and" pinning direction E1 "are anti-parallel to each other, resulting in a positive Δ R change in resistance value, where Δ R is greater than 0.

On the contrary, the second and third portions P2, P3 (upper right and lower left portions) sense the magnetic field component with the magnetic field direction of D2 due to the relationship of the magnetic flux concentrator 110, and the pinning direction E1 of the one-directional magnetoresistive sensor 120 is the direction D2, so that the first and second one- directional magnetoresistive sensors 1201, 1202 in the second and third portions P2, P3 are due to the "transformed external magnetic field H_D1The magnetic field direction "and" pinning direction E1 "are parallel to each other, resulting in a change in resistance value thereof by a negative Δ R, where Δ R is greater than 0.

Therefore, since the resistance changes of the first and third portions P1 and P3 in the first wheatstone full-bridge FWH1 (the resistance value of the first portion P1 changes to positive and the resistance value of the third portion P3 changes to negative) and the resistance changes of the second and fourth portions P2 and P4 in the second wheatstone full-bridge FWH2 (the resistance value of the second portion P2 changes to negative and the resistance value of the fourth portion P4 changes to positive) are opposite to each other, the signal directions of the first and second electrical signals output by the first and second wheatstone full-bridges FWH1 and FWH2, respectively, are opposite to each other. The calculator 130 performs a subtraction operation according to the first and second electrical signals, and determines the external magnetic field H according to the subtraction result_D1Magnitude and sign in direction D1.

Referring to fig. 2B and fig. 4B, when the magnetic field sensing device 100 is placed in the external magnetic field H with the magnetic field direction D2_D2Medium, generally speaking, external magnetic field H_D2And is less likely to be affected by the flux concentrator 110 to change its direction. Accordingly, the pinning direction E1 of the first and second one- directional magnetoresistive sensors 1201, 1202 in the first to fourth portions P1-P4 and the external magnetic field H_D2The two directions are parallel to each other, so that the resistance of each of the unidirectional magnetoresistive sensors 120 is changed by a negative Δ R, wherein Δ R is greater than 0.

Therefore, the magnetoresistive sensor 12 is configured to form two Wheatstone full bridges FWH1, FWH20, i.e. a voltage difference signal of 0 is measured between the two voltage outputs of each of the wheatstone and full bridges FWH1, FWH2, the external magnetic field H is equal_D2Is not sensed by the architecture of the first and second wheatstone full-bridges FWH1, FWH 2.

Referring to fig. 2C and fig. 4C, when the magnetic field sensing device 100 is placed in the external magnetic field H with the magnetic field direction D3_D3Medium, external magnetic field H_D3Will be directed by the influence of the flux concentrator 110. That is, the external magnetic field H_D3The original direction D2 is transformed into a magnetic field in the direction D2 or in the direction opposite to the direction D2, and the unidirectional mr sensor 120 at different positions has different resistance variations due to different magnetic field directions.

In detail, the first and second portions P1 and P2 (upper left and upper right portions) sense the magnetic field component in the opposite direction of the magnetic field direction D2 due to the relationship of the magnetic flux concentrator 110, and the pinning direction E1 of the one-way magnetoresistive sensor 120 is the direction D2, so that the first and second one- way magnetoresistive sensors 1201 and 1202 in the first and second portions P1 and P2 are caused by the "transformed external magnetic field H_D3The magnetic field direction "and" pinning direction E1 "are anti-parallel to each other, resulting in a positive Δ R change in resistance value, where Δ R is greater than 0.

Referring to fig. 4C and comparing fig. 2C, on the contrary, the third and fourth portions P3 and P4 (lower left and lower right portions) sense the magnetic field component with the direction D2 due to the relationship of the magnetic flux concentrator 110, and the pinning direction E1 of the one-way magnetoresistive sensor 120 is the direction D2, so that the first and second one- way magnetoresistive sensors 1201 and 1202 in the third and fourth portions P3 and P4 are due to the "transformed external magnetic field H_D3The magnetic field direction "and" pinning direction E1 "are parallel to each other, resulting in a change in resistance value thereof by a negative Δ R, where Δ R is greater than 0.

Therefore, the first benefits are similar to the resistance changes of the first and third portions P1 and P3 (the resistance value of the first portion P1 is positive, and the resistance value of the third portion P3 is negative) and the second benefits of the full-bridge FWH1Since the resistance changes of the second and fourth portions P2 and P4 of the full-bridge FWH2 (the resistance value change of the second portion P2 is positive and the resistance value change of the fourth portion P4 is negative) are the same, the signal directions of the first and second electric signals output by the first and second full-bridges FWH1 and FWH2 are the same. The calculator 130 performs an addition operation based on the first and second electric signals, and determines the external magnetic field H based on the addition result_D3Magnitude and sign in direction D3.

In view of the above, in the magnetic field sensing device 100 of the present 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. In the magnetic field sensing device 100, the one-directional magnetoresistive sensors 120 are respectively disposed near the opposite ends EP1 and EP2 of the magnetic flux concentrator 110 to form two wheats full bridges FWH1 and FWH2, respectively, and multi-axis sensing (for example, two-axis sensing, which can determine magnetic field components of an external magnetic field in two different directions D1 and D3) is realized by electric signals output by the two wheats full bridges FWH1 and FWH2 under the influence of an external magnetic field. Since the circuit architectures of the first and second wheatstone full bridges FWH1 and FWH2 are distributed in the corresponding end regions EP1 and EP2, the circuit architectures are simpler and less complex, and the manufacturing cost can be effectively reduced.

It should be noted that, the following embodiments follow the contents of the foregoing embodiments, descriptions of the same technical contents are omitted, reference may be made to the contents of the foregoing embodiments for the same element names, and repeated descriptions of the following embodiments are omitted. In addition, in order to clearly show the drawing, reference numerals of elements which are partially identical to those of the previous embodiment are omitted in the drawings described in the lower paragraph.

Fig. 5A to 7A are schematic top views of magnetic field sensing devices according to different embodiments of the present invention in a first time interval. Fig. 5B to 7B are schematic top views of the magnetic field sensing device of fig. 5A and 7A at 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.

Referring 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, with the main differences: the magnetic field sensing device 100a further includes a time-sharing switching circuit 140, wherein the time-sharing switching circuit 140 is coupled to the one-directional magnetoresistive sensors 120 and is configured to switch at least a portion of a connection point between the one-directional magnetoresistive sensors 120 to change a circuit connection between the magnetoresistive sensors 120, so as to form another wheatstone full bridge having a different configuration from the first and second wheatstone full bridges FWH1 and FWH 2. In this embodiment, the magnetoresistive sensors 120 further include a plurality of third unidirectional magnetoresistive sensors 1203. In the present embodiment, the third unidirectional magnetoresistive sensors 1203 are disposed to overlap the middle portion MP.

In the present embodiment, the magnetic field sensing device 100a can measure the magnetic field components in the directions D1-D3 by switching the circuit connection among the one-way magnetoresistive sensors 120 at different time intervals through the time-sharing switching circuit 140. In other words, the magnetic field sensing device 100a of the present embodiment can implement three-axis sensing. In the following paragraphs, how the magnetic field sensing device 100a measures the magnetic field components in the directions D1-D3 will be described in sections.

Referring to fig. 5A, in the first time interval, the time-sharing switching circuit 140 forms two wheatstone full bridges FWH1 and FWH2 with the first and second unidirectional magnetoresistive sensors 1201 and 1202 respectively to measure the magnetic field components in the directions D1 and D3. The principle of the magnetic field sensing device 100a measuring the magnetic field components in the directions D1 and D3 is substantially similar to the magnetic field sensing device 100 of fig. 1, and is not repeated herein.

Referring to fig. 5B, in the second time interval, the time-sharing switching circuit 140 may select at least a portion of the one-directional magnetoresistive sensors 120 from the first to fourth portions P1-P4 and couple with the third one-directional magnetoresistive sensors 1203 to form a third wheatstone full bridge FWH 3. For example, the time-sharing switching circuit 140 selects two first unidirectional magnetoresistive sensors 1201 of the first and third parts P1 and P3 closest to the third unidirectional magnetoresistive sensor 1203 to couple to the full bridge.

Referring to FIG. 5B and referring to FIG. 2B, when the magnetic field sensing device 100a is placed in the external magnetic field H with the magnetic field direction D2_D2In the middle time, since the third one-directional magnetoresistive sensor 1203 is shielded by the magnetic flux concentrator 110, it does not sense the external magnetic field H_D2The two first one-way magnetic sensors 1201 are induced by the external magnetic field H_D2The effect is to produce a negative Δ R change in its resistance value. Therefore, when the third Wheatstone full bridge FWH3 is subjected to the external magnetic field H_D2Under the influence of the above, the resistance of the third one-way magnetoresistive sensor 1203 is not changed, and the resistance of the two first one-way magnetoresistive sensors 1201a is changed by the negative Δ R, so that the voltage difference signal (i.e. the third electrical signal) measured between the two voltage output terminals of the third wheatstone and full-bridge FWH3 is a non-zero electrical signal, that is, the external magnetic field H is applied_D2Can be sensed by the architecture of the third hewlett-packard full-bridge FWH 3. The calculator 130 determines the external magnetic field H according to the third electrical signal_D2Magnitude and sign in direction D2.

In other embodiments, the time-sharing switching circuit 140 may also select other first and second unidirectional magnetoresistive sensors 1201, 1202 and couple with the third unidirectional magnetoresistive sensor 1203 to form a third wheatstone full bridge FWH3, which is not limited to the invention.

Referring 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, with the main differences: in the magnetic field sensing device 100b, the third unidirectional magnetoresistive sensor 1203 can be divided into a fifth part P5 and a sixth part P6 according to different positions. The sixth section P6 in turn comprises two sixth subsections SP 6. The fifth part P5 is disposed to overlap the middle part MP, and the second sixth sub-parts SP6 are disposed beside opposite sides (upper and lower sides) of the middle part MP, respectively, and are not disposed to overlap the middle part MP.

Referring to fig. 6A, in the first time interval, the time-sharing switching circuit 140 forms two wheatstone full bridges FWH1 and FWH2 with the first and second unidirectional magnetoresistive sensors 1201 and 1202 respectively to measure the magnetic field components in the directions D1 and D3. The principle of the magnetic field sensing device 100a measuring the magnetic field components in the directions D1 and D3 is substantially similar to the magnetic field sensing device 100 of fig. 1, and is not repeated herein.

Referring to fig. 6B, in the second time interval, the time-sharing switching circuit 140 couples the fifth and sixth portions P5 and P6 to the third wheatstone full bridge FWH 3B. Based on the principle similar to the magnetic field sensing device 100a of FIG. 5B, when the third Wheatstone full bridge FWH3B is subjected to the external magnetic field H_D2Under the influence, the third one-way magnetoresistive sensor 1203 belonging to the sixth part P6 in the third Wheatstone full bridge FWH3b may be influenced by the external magnetic field H_D2The resistance value is changed, and the value belonging to the fifth portion P5 is not, so that the third wheatstone full bridge FWH3b can output a non-zero third electrical signal. The calculator 130 determines the external magnetic field H according to the third electrical signal_D2Magnitude and sign in direction D2.

Referring 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, with the main differences: the third one-directional magnetoresistive sensors 1203 are disposed at different positions. In detail, the third unidirectional magnetoresistive sensor 1203 includes fifth and sixth sections P5c, P6 c. The fifth portion P5c is disposed beside the short side (i.e., the left short side SE1) belonging to the first end EP1 and is disposed without overlapping the first end EP1, and the sixth portion P6c is disposed beside the short side (i.e., the right short side SE2) belonging to the second end EP2 and is disposed without overlapping the second end EP 2.

Referring to fig. 7A, in the first time interval, the time-sharing switching circuit 140 forms two wheatstone full bridges FWH1 and FWH2 with the first and second unidirectional magnetoresistive sensors 1201 and 1202 respectively to measure the magnetic field components in the directions D1 and D3. The principle of the magnetic field sensing device 100c measuring the magnetic field components in the directions D1 and D3 is substantially similar to the magnetic field sensing device 100 of fig. 1, and is not repeated herein.

Referring to fig. 7B, in the second time interval, the time-sharing switching circuit 140 couples the fifth and sixth portions P5c and P6c to the third wheatstone full bridge FWH3 c. Referring to FIG. 2B, when the third Wheatstone full-bridge FWH3c receives an external magnetic field H_D2When influenced, the external magnetic field H at the positions of the fifth and sixth parts P5c and P6c_D2The magnetic field direction of the magnetic flux concentrator 110 is changed to the direction D1, so that the unidirectional third magnetoresistive sensor 1203 is influenced by the magnetic flux concentrator110 senses a magnetic field in direction D1, which causes its resistance to change. The third wheatstone full bridge FWH3c may output a non-zero third electrical signal. The calculator 130 determines the external magnetic field H according to the third electrical signal_D2Magnitude and sign in direction D2.

Referring 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, with the main differences: the magnetic field sensing device 100d further comprises a unidirectional magnetic field sensing element 150 coupled to the calculator 130. In the above description, the first and second wheatstone full bridges FWH1 and FWH2 formed by the unidirectional magnetoresistive sensors 120 are used for measuring the magnetic field components in the directions D1 and D3, and the unidirectional magnetic field sensing element 150 is used for measuring the magnetic field component in the direction D2, so that the magnetic field sensing apparatus 100D of the present embodiment realizes three-axis sensing. That is, the one-directional magnetic field sensing element 150 may output an electrical signal (i.e., the third electrical signal) under the influence of the external magnetic field, and the calculator 130 may determine the magnetic field component in the direction D2 according to the electrical signal output by the one-directional magnetic field sensing element 150. One skilled in the art can construct the one-directional magnetic field sensing element 150 capable of functionally measuring the magnetic field component in the direction D2 by various different magneto-resistive sensors, which should not be construed as a limitation to the invention.

In summary, in the magnetic field sensing device according to the embodiment of the invention, since the pinning directions of the unidirectional magnetoresistive sensors are all the same, the manufacturing process is simple, the cost is low, and the stability is good. In addition, the magnetic field sensing device respectively arranges the one-way magnetoresistive sensors beside the two opposite end parts of the magnetic flux concentrator to form two Wheatstone full bridges respectively, and realizes multi-axis sensing through electric signals output by the two Wheatstone full bridges under the influence of an external magnetic field.

Although the present invention has been described with reference to the above embodiments, it should be understood that various changes and modifications can be made therein by those skilled in the art without departing from the spirit and scope of the invention.