阅读说明：本技术 磁场感测装置 (Magnetic field sensing device ) 是由 袁辅德 于 2020-03-17 设计创作，主要内容包括：本发明提供一种磁场感测装置,包括多个第一磁电阻单元、多个第二磁电阻单元、一第一测试导线、一第二测试导线及一驱动器。这些第一磁电阻单元沿着一第一方向排列。这些第二磁电阻单元沿着第一方向排列,且这些第二磁电阻单元配置于这些第一磁电阻单元于一第二方向上的一侧。第一测试导线配置于这些第一磁电阻单元于一第三方向上的一侧,且沿着第一方向延伸。第二测试导线配置于这些第二磁电阻单元于第三方向上的一侧,且沿着第一方向延伸。驱动器用以在不同的时间分别使两同向电流及两反向电流流经第一测试导线与第二测试导线。此磁场感测装置能够内建自我测试的功能。(The invention provides a magnetic field sensing device, which comprises a plurality of first magneto-resistance units, a plurality of second magneto-resistance units, a first test lead, a second test lead and a driver. The first magnetoresistive cells are arranged along a first direction. The second magnetoresistive units are arranged along the first direction and are configured at one side of the first magnetoresistive units in a second direction. The first test wires are arranged on one side of the first magneto-resistance units in a third direction and extend along the first direction. The second test wires are arranged on one side of the second magneto-resistance units in the third direction and extend along the first direction. The driver is used for enabling two same-direction currents and two reverse-direction currents to flow through the first test conducting wire and the second test conducting wire respectively at different time. The magnetic field sensing device can be built in with a self-test function.)

1. A magnetic field sensing device, comprising:

the first magnetoresistive units are arranged along a first direction, wherein the sensing direction of each first magnetoresistive unit is perpendicular to the first direction;

a plurality of second magnetoresistive units arranged along the first direction, wherein the sensing direction of each second magnetoresistive unit is perpendicular to the first direction, and the plurality of second magnetoresistive units are configured at one side of the plurality of first magnetoresistive units in the second direction;

the first test lead is configured at one side of the first magneto-resistance units in the third direction and extends along the first direction;

the second test lead is configured at one side of the second magneto-resistance units in the third direction and extends along the first direction; and

and the driver is electrically connected to the first test lead and the second test lead and is used for enabling two currents in the same direction and two currents in the opposite directions to flow through the first test lead and the second test lead respectively at different times.

2. The magnetic field sensing device according to claim 1, wherein the first and second magnetoresistive cells include anisotropic magnetoresistors, and the magnetic field sensing device includes at least one magnetization direction setting element disposed at one side of the first and second magnetoresistive cells in the third direction and configured to set the magnetization directions of the anisotropic magnetoresistors to at least one of the first direction and an opposite direction of the first direction, respectively.

3. The magnetic field sensing device according to claim 1, wherein the first plurality of magnetoresistive cells and the second plurality of magnetoresistive cells are electrically connected in at least one wheatstone bridge to output a voltage signal corresponding to the magnetic field component in the second direction or to output a voltage signal corresponding to the magnetic field component in the second direction and the magnetic field component in the third direction.

4. The magnetic field sensing device according to claim 1, wherein the sensing direction of each first magnetoresistive cell is tilted with respect to the second direction, the sensing direction of each second magnetoresistive cell is tilted with respect to the second direction, and the tilting direction of the sensing direction of each first magnetoresistive cell with respect to the second direction is opposite to the tilting direction of the sensing direction of each second magnetoresistive cell with respect to the second direction.

5. The magnetic field sensing device according to claim 4, wherein the sense direction of each first magnetoresistive cell is tilted with respect to the second direction by the same degree as the sense direction of each second magnetoresistive cell is tilted with respect to the second direction.

6. The magnetic field sensing device according to claim 1, further comprising:

a plurality of third magnetoresistive cells arranged along the first direction, wherein a sensing direction of each third magnetoresistive cell is perpendicular to the first direction;

a plurality of fourth magnetoresistive units arranged along the first direction, wherein the sensing direction of each fourth magnetoresistive unit is perpendicular to the first direction, and the plurality of first, second, third and fourth magnetoresistive units are sequentially arranged in the second direction;

a third testing conductive line disposed on one side of the plurality of third magnetoresistive units in the third direction and extending along the first direction, wherein the third testing conductive line is connected in parallel with the first testing conductive line; and

and a fourth test wire, configured on one side of the fourth magnetoresistance units in the third direction, and extending along the first direction, wherein the fourth test wire is connected in parallel with the second test wire.

7. The magnetic field sensing device according to claim 6, wherein the first, second, third and fourth plurality of magnetoresistive units are electrically connected to at least one wheatstone bridge for outputting a voltage signal corresponding to the magnetic field component in the second direction or outputting a voltage signal corresponding to the magnetic field component in the second direction and the magnetic field component in the third direction.

8. The magnetic field sensing device according to claim 6, wherein the first, second, third and fourth magnetoresistive cells comprise anisotropic magnetoresistors, and the magnetic field sensing device comprises at least one magnetization direction setting element disposed at one side of the first, second, third and fourth magnetoresistive cells in the third direction and configured to set the magnetization directions of the anisotropic magnetoresistors to at least one of the first direction and an opposite direction of the first direction, respectively.

9. The magnetic field sensing device according to claim 6, wherein the sensing direction of each first magnetoresistive cell, the sensing direction of each second magnetoresistive cell, the sensing direction of each third magnetoresistive cell, and the sensing direction of each fourth magnetoresistive cell are tilted with respect to the second direction, the sensing direction of each first magnetoresistive cell is tilted with respect to the second direction opposite to the tilting direction of the sensing direction of each second magnetoresistive cell with respect to the second direction, the sensing direction of each third magnetoresistive cell is tilted with respect to the second direction in the same direction as the tilting direction of the sensing direction of each first magnetoresistive cell with respect to the second direction, and the sensing direction of each fourth magnetoresistive cell is inclined relative to the second direction in the same way as the sensing direction of each second magnetoresistive cell is inclined relative to the second direction.

10. The magnetic field sensing device according to claim 9, wherein the sense direction of each first magnetoresistive cell is tilted with respect to the second direction by the same degree as the sense direction of each second magnetoresistive cell is tilted with respect to the second direction, the sense direction of each third magnetoresistive cell is tilted with respect to the second direction by the same degree as the sense direction of each fourth magnetoresistive cell is tilted with respect to the second direction, and the sense direction of each first magnetoresistive cell is tilted with respect to the second direction by the same degree as the sense direction of each third magnetoresistive cell is tilted with respect to the second direction.

11. The magnetic field sensing device according to claim 1, further comprising:

a substrate, wherein the first test lead and the second test lead are disposed on the substrate; and

the insulating layer covers the first test wire and the second test wire, a groove is formed in the top of the insulating layer, the groove is provided with two opposite inclined side walls, and the plurality of first magneto-resistance units and the plurality of second magneto-resistance units are respectively arranged on the two inclined side walls.

Technical Field

The present invention relates to a magnetic field sensing device.

Background

Magnetometers (magnetometers) are important components for systems with compass and motion tracking functionality, and for portable systems such as smart phones, tablet computers or smart watches or industrial systems such as unmanned aerial vehicles (drones), magnetometers need to have very small package sizes and high energy efficiency at high output data rates (outputdata rates). These requirements have made Magnetoresistive (MR) sensors, including Anisotropic Magnetoresistive (AMR) sensors, Giant Magnetoresistive (GMR) sensors, and Tunneling Magnetoresistive (TMR) sensors, mainstream.

Self-monitoring of the device itself is an essential function for advanced applications such as Artificial Intelligence (AI), industrial 4.0 (industrial 4.0) or systems with a high degree of automation. Therefore, in the development of magnetometers, built-in self-test technology (building-in self-test technology) is becoming an important development direction.

Disclosure of Invention

The present invention is directed to a magnetic field sensing device with built-in self-test functionality.

An embodiment of the invention provides a magnetic field sensing device, which includes a plurality of first magnetoresistive units, a plurality of second magnetoresistive units, a first test wire, a second test wire, and a driver. The first magnetoresistive cells are arranged along a first direction, wherein the sensing direction of each first magnetoresistive cell is perpendicular to the first direction. The second magnetoresistive units are arranged along a first direction, wherein the sensing direction of each second magnetoresistive unit is perpendicular to the first direction, and the second magnetoresistive units are arranged on one side of the first magnetoresistive units in a second direction. The first test wires are arranged on one side of the first magneto-resistance units in a third direction and extend along the first direction. The second test wires are arranged on one side of the second magneto-resistance units in the third direction and extend along the first direction. The driver is electrically connected to the first test wire and the second test wire and is used for enabling two currents in the same direction and two currents in the opposite directions to flow through the first test wire and the second test wire respectively at different times.

In an embodiment of the invention, the first magnetoresistive cells and the second magnetoresistive cells include a plurality of anisotropic magnetoresistances, and the magnetic field sensing device includes at least one magnetization direction setting element disposed at one side of the first magnetoresistive cells and the second magnetoresistive cells in a third direction and configured to set the magnetization directions of the anisotropic magnetoresistances to at least one of the first direction and an opposite direction of the first direction, respectively.

In an embodiment of the invention, the first magnetoresistive units and the second magnetoresistive units are electrically connected to form at least one wheatstone bridge for outputting a voltage signal corresponding to the magnetic field component in the second direction or outputting a voltage signal corresponding to the magnetic field component in the second direction and the magnetic field component in the third direction.

In an embodiment of the invention, a sensing direction of each first magnetoresistive cell is inclined with respect to the second direction, a sensing direction of each second magnetoresistive cell is inclined with respect to the second direction, and the inclination direction of the sensing direction of each first magnetoresistive cell with respect to the second direction is opposite to the inclination direction of the sensing direction of each second magnetoresistive cell with respect to the second direction.

In an embodiment of the invention, a sensing direction of each first magnetoresistive cell is tilted with respect to the second direction by the same degree as a sensing direction of each second magnetoresistive cell is tilted with respect to the second direction.

In an embodiment of the invention, the magnetic field sensing device further includes a plurality of fourth magnetoresistive cells, a third test wire and a fourth test wire. The third magnetoresistive cells are arranged along a first direction, wherein a sensing direction of each third magnetoresistive cell is perpendicular to the first direction. The fourth magnetoresistive units are arranged along a first direction, wherein the sensing direction of each fourth magnetoresistive unit is perpendicular to the first direction, and the first, second, third and fourth magnetoresistive units are sequentially arranged in a second direction. The third testing wires are arranged on one side of the third magneto-resistance units in the third direction and extend along the first direction, wherein the third testing wires are connected with the first testing wires in parallel. The fourth test conducting wires are configured on one side of the fourth magneto-resistance units in the third direction and extend along the first direction, wherein the fourth test conducting wires are connected with the second test conducting wires in parallel.

In an embodiment of the invention, the first, second, third and fourth magnetoresistive units are electrically connected to form at least one wheatstone bridge for outputting a voltage signal corresponding to the magnetic field component in the second direction or outputting a voltage signal corresponding to the magnetic field component in the second direction and the magnetic field component in the third direction.

In an embodiment of the invention, the first, second, third and fourth magnetoresistive units include a plurality of anisotropic magnetoresistors, and the magnetic field sensing device includes at least one magnetization direction setting element disposed at one side of the first, second, third and fourth magnetoresistive units in the third direction and configured to set the magnetization directions of the anisotropic magnetoresistors to at least one of the first direction and an opposite direction of the first direction, respectively.

In an embodiment of the invention, a sensing direction of each first magnetoresistive cell, a sensing direction of each second magnetoresistive cell, a sensing direction of each third magnetoresistive cell, and a sensing direction of each fourth magnetoresistive cell are all tilted with respect to the second direction, the tilting direction of the sensing direction of each first magnetoresistive cell with respect to the second direction is opposite to the tilting direction of the sensing direction of each second magnetoresistive cell with respect to the second direction, the tilting direction of the sensing direction of each third magnetoresistive cell with respect to the second direction is the same as the tilting direction of the sensing direction of each first magnetoresistive cell with respect to the second direction, and the tilting direction of the sensing direction of each fourth magnetoresistive cell with respect to the second direction is the same as the tilting direction of the sensing direction of each second magnetoresistive cell with respect to the second direction.

In an embodiment of the invention, a degree of inclination of the sensing direction of each first magnetoresistive cell with respect to the second direction is the same as a degree of inclination of the sensing direction of each second magnetoresistive cell with respect to the second direction, a degree of inclination of the sensing direction of each third magnetoresistive cell with respect to the second direction is the same as a degree of inclination of the sensing direction of each fourth magnetoresistive cell with respect to the second direction, and a degree of inclination of the sensing direction of each first magnetoresistive cell with respect to the second direction is the same as a degree of inclination of the sensing direction of each third magnetoresistive cell with respect to the second direction.

In an embodiment of the invention, the magnetic field sensing device further includes a substrate and an insulating layer. The first test lead and the second test lead are arranged on the substrate. The insulating layer covers the first test wire and the second test wire, the top of the insulating layer is provided with a groove, the groove is provided with two opposite inclined side walls, and the first magnetoresistance units and the second magnetoresistance units are respectively arranged on the two inclined side walls.

In the magnetic field sensing device according to the embodiment of the invention, the first test wire and the second test wire are adopted, and the driver is utilized to respectively enable two currents in the same direction and two currents in opposite directions to flow through the first test wire and the second test wire at different times, so that the magnetic field sensing device can be built in with a self-test function.

Drawings

The accompanying drawings are included to provide a further understanding of the invention, and are incorporated in and constitute a part of this specification. The drawings illustrate embodiments of the invention and together with the description serve to explain the principles of the invention.

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

FIG. 1B is a cross-sectional view of the magnetic field sensing device of FIG. 1A along line I-I;

FIG. 2A is a schematic top view of the magnetic field sensing device of FIG. 1A when a driver applies a reverse current to the first test conductive line and the second test conductive line;

FIG. 2B is a cross-sectional view of the magnetic field sensing device of FIG. 2A along line I-I;

FIG. 3A is a schematic top view of the magnetic field sensing device of FIG. 1A when the driver applies currents in the same direction to the first test conductive line and the second test conductive line;

FIG. 3B is a cross-sectional view of the magnetic field sensing device of FIG. 3A along line I-I;

FIGS. 4A and 4B are diagrams illustrating the operation of the anisotropic magnetoresistance of FIG. 1A;

FIG. 5 shows the first, second, third and fourth magnetoresistive cells of FIG. 1A connected as a Wheatstone bridge;

FIG. 6A is a schematic top view of a magnetic field sensing device according to another embodiment of the present invention;

FIG. 6B is a cross-sectional view of the magnetic field sensing device of FIG. 6A along line II-II;

FIG. 7 shows the first, second, third and fourth magnetoresistive cells of FIG. 6A connected in another Wheatstone bridge;

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

FIG. 9 is a schematic top view of a test lead of a magnetic field sensing device according to yet another embodiment of the present invention;

fig. 10 is a schematic top view of a test lead of a magnetic field sensing device according to another embodiment of the invention.

Description of the reference numerals

100. 100a, 100 b: magnetic field sensing device

110: first magneto-resistance unit

120: second magnetoresistive cell

130: third magnetoresistive cell

140: fourth magnetoresistive cell

210: first test wire

220: second test wire

230: third test wire

240: fourth test wire

250: fifth test wire

260: sixth test wire

300: anisotropic magnetoresistance

310: short-circuit bar

320: ferromagnetic film

400: driver

500. 510, 520: magnetization direction setting element

610: substrate

620. 630 and 640: insulating layer

642: groove

B1, B2: magnetic field

D: direction of extension

D1: a first direction

D2: second direction

D3: third direction

H: external magnetic field

H1, H2: direction of rotation

i: electric current

J1, J2: electric current

L1, L2, L3, L4: inclined side wall

M: direction of magnetization

P1, P2, P3, P4, P5, P6, P7, P8, P9, P10, P11, P12: endpoint

S1, S2, S3, S4: sensing direction

VDD: reference voltage

Detailed Description

Reference will now be made in detail to exemplary embodiments of the invention, examples of which are illustrated in the accompanying drawings. Wherever possible, the same reference numbers will be used throughout the drawings and the description to refer to the same or like parts.

Fig. 1A is a schematic top view of a magnetic field sensing device according to an embodiment of the invention, and fig. 1B is a schematic cross-sectional view of the magnetic field sensing device of fig. 1A along the line I-I. Referring to fig. 1A and 1B, the magnetic field sensing apparatus 100 of the present embodiment includes a plurality of first magnetoresistive units 110, a plurality of second magnetoresistive units 120, a first test wire 210, a second test wire 220, and a driver 400. The first magnetoresistive cells 110 are arranged along a first direction D1, wherein the sensing direction S1 of each first magnetoresistive cell 110 is perpendicular to the first direction D1. The second magnetoresistive cells 120 are arranged along the first direction D1, wherein the sensing direction S2 of each second magnetoresistive cell 120 is perpendicular to the first direction D1, and the second magnetoresistive cells 120 are disposed at one side of the first magnetoresistive cells 110 in a second direction D2. The first test conductive line 210 is disposed on one side of the first magnetoresistive cells 110 in a third direction D3 and extends along the first direction D1. The second test conductive line 220 is disposed on one side of the second magnetoresistive cells 120 in the third direction D3 and extends along the first direction D1. In the present embodiment, the first direction D1, the second direction D2 and the third direction D3 are perpendicular to each other. However, in other embodiments, the first direction D1, the second direction D2, and the third direction D3 may be three different directions that are not perpendicular to each other.

The driver 100 is electrically connected to the first test wire 210 and the second test wire 220, and is configured to enable two currents in the same direction and two currents in opposite directions to flow through the first test wire 210 and the second test wire 220 at different times.

In this embodiment, the magnetic field sensing apparatus 100 further includes a plurality of third magnetoresistive units 130, a plurality of fourth magnetoresistive units 140, a third test wire 230 and a fourth test wire 240. The third magnetoresistive cells 130 are arranged along a first direction D1, wherein a sensing direction S3 of each third magnetoresistive cell 130 is perpendicular to the first direction D1. The fourth magnetoresistive cells 140 are arranged along the first direction D1, wherein the sensing direction S4 of each fourth magnetoresistive cell 140 is perpendicular to the first direction D1. The first, second, third and fourth magnetoresistive cells 110, 120, 130 and 140 are sequentially arranged in the second direction D2. The third testing conductive line 230 is disposed on one side of the third magnetoresistive units 130 in the third direction D3 and extends along the first direction D1, wherein the third testing conductive line 230 is connected in parallel with the first testing conductive line 210. The fourth test conductive line 240 is disposed on one side of the fourth magnetoresistive units 140 along the third direction D3 and extends along the first direction D1, wherein the fourth test conductive line 240 is connected in parallel with the second test conductive line 220.

FIG. 2A is a top view of the magnetic field sensing device of FIG. 1A when a driver applies a reverse current to a first test conductive line and a second test conductive line, and FIG. 2B is a cross-sectional view of the magnetic field sensing device of FIG. 2A along line I-I. FIG. 3A is a top view of the magnetic field sensing device of FIG. 1A when the driver applies currents in the same direction to the first test conductive line and the second test conductive line, and FIG. 3B is a cross-sectional view of the magnetic field sensing device of FIG. 3A along the line I-I. Referring to fig. 2A and 2B, at a first time, the driver 400 makes two reverse currents J1 and J2 respectively flow through the first test wire 210 and the second test wire 220, and makes two reverse currents J1 and J2 respectively flow through the third test wire 230 and the fourth test wire 240, wherein the direction of the current J1 is, for example, towards the first direction D1, and the direction of the current J2 is, for example, towards the opposite direction of the first direction D1. At this time, in the cross section of fig. 2B, the first test conducting line 210 and the third test conducting line 230 generate a magnetic field B1 in a counterclockwise direction, so that the first magnetoresistive cells 110 and the third magnetoresistive cells 130 sense a magnetic field parallel to the second direction D2 (e.g., a magnetic field in a direction opposite to the second direction D2). In addition, the second test wire 220 and the fourth test wire 240 generate a clockwise magnetic field B2, so that the second magnetoresistive cells 120 and the fourth magnetoresistive cells 140 sense a magnetic field parallel to the second direction D2 (e.g., a magnetic field facing the second direction D2), but the direction H1 is opposite to the direction H2 of the magnetic field sensed by the first magnetoresistive cell 110 and the third magnetoresistive cell 130. In the present embodiment, the direction H1 is opposite to the second direction D2, and the direction H2 is the same as the second direction D2. Specifically, the switch element (switch) in the driver 400 connects the node P1 and the node P3 to be turned on, and the driver 400 injects a current into the node P4 to flow a current from the node P2, so that the current J1, the current J2, the current J1 and the current J2 can be generated in the first, second, third and fourth test wires 210, 220, 230 and 240, respectively.

At a second time different from the first time, as shown in fig. 3A and 3B, the driver 400 makes a same-direction current J2 flow through the first test wire 210 and the second test wire 220, and makes a same-direction current J2 flow through the third test wire 230 and the fourth test wire 240. At this time, in the cross section of fig. 3B, the first test conducting line 210, the second test conducting line 220, the third test conducting line 230, and the fourth test conducting line 240 all generate a clockwise magnetic field B2, so that the first magnetoresistive cells 110, the second magnetoresistive cells 120, the third magnetoresistive cells 130, and the fourth magnetoresistive cells 140 all sense a magnetic field parallel to the second direction D2, and the directions H2 of the magnetic fields sensed by the first, second, third, and fourth magnetoresistive cells 110, 120, 130, and 140 are all the same. Specifically, the switch element (switch) in the driver 400 connects the node P1 and the node P4 to be turned on, and the driver 400 injects a current into the node P2 to flow out from the node P3, so that a current J2 can be generated in the first, second, third and fourth test wires 210, 220, 230 and 240.

In this way, the magnetic fields B1 and B2 generated at the first time and the second time can be used as the reference magnetic fields of the first, second, third and fourth magnetoresistive units 110, 120, 130 and 140, so that the circuits of the first, second, third and fourth magnetoresistive units 110, 120, 130 and 140 can correct the first, second, third and fourth magnetoresistive units 110, 120, 130 and 140 by the reference magnetic fields, and the magnetic field sensing apparatus 100 of the present embodiment can have a built-in self-test function.

Referring to fig. 1A and 1B again, in the present embodiment, the first magnetoresistive units 110, the second magnetoresistive units 120, the third magnetoresistive units 130, and the fourth magnetoresistive units 140 include a plurality of anisotropic magnetoresistances, and the magnetic field sensing apparatus 100 includes at least one magnetization direction setting element 500 (two magnetization direction setting elements 510 and 520 are taken as examples in fig. 1A), disposed on one side of the first magnetoresistive units 110, the second magnetoresistive units 120, the third magnetoresistive units 130, and the fourth magnetoresistive units 140 in the third direction D3, and configured to set the magnetization directions of the anisotropic magnetoresistances to at least one of the opposite directions of the first direction D1 and the first direction D1, respectively. For example, the magnetization direction setting element 510 is disposed below the first, second, third, and fourth magnetoresistive cells 110, 120, 130, and 140 on the left half of fig. 1A, and the magnetization direction setting element 520 is disposed below the first, second, third, and fourth magnetoresistive cells 110, 120, 130, and 140 on the right half of fig. 1A. The magnetization direction setting elements 510 and 520 are, for example, conductive wires, which extend along the second direction D2. The magnetization direction setting element 510 is adapted to be applied with a current in a reverse direction of the second direction D2 to set the magnetization directions of the first, second, third, and fourth magnetoresistive cells 110, 120, 130, and 140 on the left half of fig. 1A to be in a reverse direction of the first direction D1, and the magnetization direction setting element 520 is adapted to be applied with a current in the second direction D2 to set the magnetization directions of the first, second, third, and fourth magnetoresistive cells 110, 120, 130, and 140 on the right half of fig. 1A to be in the first direction D1. Alternatively, the magnetization direction setting element 510 is adapted to be applied with a current in the second direction D2 to set the magnetization directions of the first, second, third and fourth magnetoresistive cells 110, 120, 130 and 140 on the left half of fig. 1A to be the first direction D1, and the magnetization direction setting element 520 is adapted to be applied with a current in the opposite direction of the second direction D2 to set the magnetization directions of the first, second, third and fourth magnetoresistive cells 110, 120, 130 and 140 on the right half of fig. 1A to be the opposite direction of the first direction D1.

FIGS. 4A and 4B are diagrams illustrating the operation of the anisotropic magnetoresistance of FIG. 1A. Referring to fig. 4A, each of the first, second, third and fourth magnetoresistive units 110, 120, 130 and 140 of fig. 1A may include one or more anisotropic magnetoresistors 300, the anisotropic magnetoresistive unit 300 has a barber pole (barber pole) -like structure, that is, a surface thereof is provided with a plurality of shorting bars (electrically shorting bars) 310 extending at an angle of 45 degrees with respect to an extending direction D of the anisotropic magnetoresistive unit 300, the shorting bars 310 are disposed on a ferromagnetic film (ferromagnetic film)320 in parallel and spaced apart from each other, and the ferromagnetic film 320 is a main body of the anisotropic magnetoresistive unit 300, and the extending direction of the ferromagnetic film is the extending direction D of the anisotropic magnetoresistive unit 300. In addition, opposite ends of the ferromagnetic film 320 may be formed in a tip shape.

Before the anisotropic magnetoresistance 300 starts measuring the external magnetic field H, the magnetization direction of the anisotropic magnetoresistance can be set by a magnetization direction setting element 510, wherein the magnetization direction setting element 510 is, for example, a coil, a wire, a metal sheet, or a conductor that can generate a magnetic field by being energized. In fig. 4A, the magnetization direction setting element 510 may generate a magnetic field along the extension direction D by applying current so that the anisotropic magnetoresistance 300 has a magnetization direction M.

Then, the magnetization direction setting element 510 is not energized, so that the anisotropic magnetoresistance 300 starts measuring the external magnetic field H. When there is no external magnetic field H, the magnetization direction M of the anisotropic magnetoresistance 300 is maintained in the extension direction D, and a current i is applied to flow from the left end to the right end of the anisotropic magnetoresistance 300, the current i near the shorting bar 310 flows perpendicular to the extension direction of the shorting bar 310, so that the current i near the shorting bar 310 flows at an angle of 45 degrees to the magnetization direction M, and the resistance value of the anisotropic magnetoresistance 300 is R.

When an external magnetic field H faces a direction perpendicular to the extending direction D, the magnetization direction M of the anisotropic magnetoresistance 300 deflects outward in the direction of the magnetic field H, so that an included angle between the magnetization direction and a current i flow direction near the shorting bar is greater than 45 degrees, and at this time, the resistance value of the anisotropic magnetoresistance 300 changes by- Δ R, i.e., becomes R- Δ R, that is, the resistance value becomes smaller, where Δ R is greater than 0.

However, as shown in fig. 4B, when the extending direction of the shorting bar 310 of fig. 4B is set to be 90 degrees from the extending direction of the shorting bar 310 of fig. 4A (at this time, the extending direction of the shorting bar 310 of fig. 4B still forms 45 degrees with the extending direction D of the anisotropic magnetoresistance 300), and when there is an external magnetic field H, the magnetization direction M is still deflected outward in the direction of the magnetic field H by the magnetic field H, and at this time, the angle between the magnetization direction M and the current i flowing direction near the shorting bar 310 is smaller than 45 degrees, so the resistance value of the anisotropic magnetoresistance 300 becomes R + Δ R, that is, the resistance value of the anisotropic magnetoresistance 300 becomes larger.

In addition, when the magnetization direction M of the anisotropic magnetoresistance 300 is set to the reverse direction shown in FIG. 4A by the magnetization direction setting element 510, the resistance value of the anisotropic magnetoresistance 300 of FIG. 4A under the external magnetic field H may become R + Δ R thereafter. Furthermore, when the magnetization direction M of the anisotropic magnetoresistance 300 is set to the reverse direction as shown in FIG. 4B by the magnetization direction setting element 510, the resistance value of the anisotropic magnetoresistance 300 of FIG. 4B under the external magnetic field H becomes R- Δ R thereafter.

In summary, when the setting direction of the shorting bar 310 is changed, the resistance value R of the anisotropic magnetoresistive film 300 changes from + Δ R to- Δ R or vice versa in response to the change of the external magnetic field H, and when the magnetization direction M set by the magnetization direction setting element 510 changes to the opposite direction, the resistance value R of the anisotropic magnetoresistive film 300 changes from + Δ R to- Δ R or vice versa in response to the change of the external magnetic field H. When the direction of the external magnetic field H is changed to the opposite direction, the resistance value R of the anisotropic magnetoresistance 300 may be changed from + Δ R to- Δ R or vice versa corresponding to the change of the external magnetic field H. However, when the current i passing through the anisotropic magnetoresistance 300 changes in the opposite direction, the resistance value R of the anisotropic magnetoresistance 300 maintains the same sign as the original resistance value corresponding to the change of the external magnetic field H, i.e., if the resistance value R is + Δ R, the resistance value R remains + Δ R after the current direction is changed, and if the resistance value R is- Δ R, the resistance value R remains- Δ R after the current direction is changed.

In accordance with the above principle, the direction of change of the resistance value R of the anisotropic magnetoresistive element 300, i.e. the resistance value R, when the anisotropic magnetoresistive element 300 is subjected to a certain component of the external magnetic field H, can be determined by designing the extension direction D of the shorting bar 310 or the magnetization direction M set by the magnetization direction setting element 510, for example, the change amount is + Δ R or- Δ R.

Fig. 5 shows the first, second, third and fourth magnetoresistive cells of fig. 1A connected as a Wheatstone bridge. Referring to fig. 1A and 5, the first, second, third and fourth magnetoresistive units 110, 120, 130 and 140 are electrically connected to at least one wheatstone bridge (e.g., the wheatstone bridge shown in fig. 5) to output a voltage signal corresponding to the magnetic field component in the second direction D2. For example, when the node P5 of the wheatstone bridge of fig. 5 receives the reference voltage VDD and the node P6 is coupled to ground, the voltage difference between the node P7 and the node P8 can be the output signal, which is a differential signal whose magnitude corresponds to the magnitude of the magnetic field component in the second direction D2. Fig. 5 also shows the extending directions of the shorting bars 310 of the first, second, third, and fourth magnetoresistive units 110, 120, 130, and 140, but this is only an example, and in other embodiments, the extending directions of the shorting bars 310 of the first, second, third, and fourth magnetoresistive units 110, 120, 130, and 140 may be other various suitable extending directions, which is not limited by the present invention. In addition, the wheatstone bridge shown in fig. 5 is only one example, and in other embodiments, the wheatstone bridges may be connected in other connection manners (i.e., other types of wheatstone bridges).

Since the first, second, third and fourth test wires 210, 220, 230 and 240 are parallel to the second direction D2 in the directions of the reference magnetic fields generated by the first, second, third and fourth magnetoresistive cells 110, 120, 130 and 140, the wheatstone bridge shown in fig. 5 can be used to correct the sensing accuracy of the wheatstone bridge for the magnetic field component in the second direction D2 when the wheatstone bridge shown in fig. 3A senses the reference magnetic field.

Referring to fig. 1B, in the present embodiment, the magnetic field sensing device 100 further includes a substrate 610, an insulating layer 620, and an insulating layer 630. The substrate 610 is, for example, a semiconductor substrate or other circuit substrate, and the driver 400 is disposed in the substrate 610 or on the substrate 610. The first, second, third and fourth test wires 210, 220, 230 and 240 are disposed on the substrate 610, and the insulating layer 630 covers the first, second, third and fourth test wires 210, 220, 230 and 240. Specifically, the insulating layer 620 covers the first, second, third and fourth test wires 210, 220, 230 and 240, the magnetization direction setting element 500 is disposed on the insulating layer 620, the insulating layer 630 covers the magnetization direction setting element 500, and the first, second, third and fourth magnetoresistive units 110, 120, 130 and 140 are disposed on the insulating layer 630.

FIG. 6A is a top view of a magnetic field sensing device according to another embodiment of the present invention, and FIG. 6B is a cross-sectional view of the magnetic field sensing device of FIG. 6A taken along line II-II. Referring to fig. 6A and 6B, the magnetic field sensing device 100a of the present embodiment is similar to the magnetic field sensing device 100 of fig. 1A and 1B, and the difference therebetween is as follows. The magnetic field sensing device 100a of the present embodiment further includes an insulating layer 640 covering the first, second, third and fourth test wires 210, 220, 230 and 240. Specifically, in the present embodiment, the insulating layer 640 is disposed on the insulating layer 630. The insulating layer 640 has a plurality of recesses 642 on the top thereof, each recess 642 having two opposing sloped sidewalls. For example, the left groove of FIG. 6B has two opposing sloped sidewalls L1 and L2, while the right groove of FIG. 6B has two opposing sloped sidewalls L3 and L4. The first magnetoresistive units 110 and the second magnetoresistive units 120 are respectively disposed on the inclined sidewall L1 and the inclined sidewall L2, and the third magnetoresistive units 130 and the fourth magnetoresistive units 140 are respectively disposed on the inclined sidewall L3 and the inclined sidewall L4.

Since the first, second, third and fourth magnetoresistive cells 110, 120, 130 and 140 are disposed on the inclined sidewalls L1, L2, L3 and L4, the sensing direction S1 of each first magnetoresistive cell 110, the sensing direction S2 of each second magnetoresistive cell 120, the sensing direction S3 of each third magnetoresistive cell 130 and the sensing direction S4 of each fourth magnetoresistive cell 140 are inclined with respect to the second direction D2. In the present embodiment, the inclination direction of the sensing direction S1 of each first magnetoresistive cell 110 with respect to the second direction D2 is opposite to the inclination direction of the sensing direction S2 of each second magnetoresistive cell 120 with respect to the second direction D2, the inclination direction of the sensing direction S3 of each third magnetoresistive cell 130 with respect to the second direction D2 is the same as the inclination direction of the sensing direction S1 of each first magnetoresistive cell 110 with respect to the second direction D2, and the inclination direction of the sensing direction S4 of each fourth magnetoresistive cell 140 with respect to the second direction D2 is the same as the inclination direction of the sensing direction S2 of each second magnetoresistive cell 120 with respect to the second direction D2.

In the present embodiment, the inclination degree of the sensing direction S1 of each first magnetoresistive cell 110 with respect to the second direction D2 is the same as the inclination degree of the sensing direction S2 of each second magnetoresistive cell 120 with respect to the second direction D2, the inclination degree of the sensing direction S3 of each third magnetoresistive cell 130 with respect to the second direction D2 is the same as the inclination degree of the sensing direction S4 of each fourth magnetoresistive cell 140 with respect to the second direction D2, and the inclination degree of the sensing direction S1 of each first magnetoresistive cell 110 with respect to the second direction D2 is the same as the inclination degree of the sensing direction S3 of each third magnetoresistive cell 130 with respect to the second direction D2.

In this embodiment, since the first, second, third and fourth magnetoresistive cells 110, 120, 130 and 140 are disposed on the inclined sidewalls, each of the anisotropic magnetoresistors can sense both the magnetic field component in the second direction D2 and the magnetic field component in the third direction D3. Therefore, when the first, second, third and fourth magnetoresistive cells 110, 120, 130 and 140 are connected as a wheatstone bridge as shown in fig. 5, and the reference voltage VDD is received at the node P5, and the node P6 is coupled to ground, the voltage difference between the node P7 and the node P8 can be an output signal, which is a differential signal whose magnitude corresponds to the magnitude of the magnetic field component in the second direction D2, and the influence of the magnetic field component in the third direction D3 on the first, second, third and fourth magnetoresistive cells 110, 120, 130 and 140 is cancelled inside the wheatstone bridge, so that the influence does not contribute to the voltage difference between the node P7 and the node P8. That is, when connected in the wheatstone bridge, only the magnetic field component in the second direction D2 can be measured, and is not affected by the magnetic field component in the third direction D3.

In addition, in another time period, the first, second, third and fourth magnetoresistive units 110, 120, 130 and 140 are connected as a wheatstone bridge as shown in fig. 7, and receive the reference voltage VDD at the node P9, and have the node P10 coupled to ground, so that the voltage difference between the node P11 and the node P12 can be an output signal, which is a differential signal whose magnitude corresponds to the magnitude of the magnetic field component in the third direction D3, and the influence of the magnetic field component in the second direction D2 on the first, second, third and fourth magnetoresistive units 110, 120, 130 and 140 is cancelled in the wheatstone bridge, so that the influence does not contribute to the voltage difference between the node P11 and the node P12. That is, when the wheatstone bridge is connected, only the magnetic field component in the third direction D3 can be measured, and the magnetic field component in the second direction D2 is not influenced.

The switching of the wheatstone bridge of fig. 5 and the wheatstone bridge of fig. 7 may be accomplished by a switching assembly located in the substrate 610. In other words, the present embodiment connects the first, second, third and fourth magnetoresistive cells 110, 120, 130 and 140 into two different wheatstone bridges to output voltage signals corresponding to the magnetic field component in the second direction D2 and the magnetic field component in the third direction, respectively. However, in other embodiments, only one wheatstone bridge may be used (for example, only the wheatstone bridge of fig. 5 is used), but the magnetization directions of the first and third magnetoresistive units 110 and 130 are changed by the magnetization direction setting element 500 at another time to change the magnetization directions to the original directions, so that the function of using only one wheatstone bridge to measure the magnetic field component in the second direction D2 and the magnetic field component in the third direction D3 at two different times can be achieved. The switching of the magnetic field generated by the magnetization direction setting element 500 can be achieved by designing the trace of the magnetization direction setting element 500 and by switching the switching circuit in the substrate 610.

Fig. 8 is a schematic top view of a magnetic field sensing device according to another embodiment of the invention. Referring to fig. 8, the magnetic field sensing device 100b of the present embodiment is similar to the magnetic field sensing device 100 of fig. 1A, and the difference therebetween is as follows. The magnetic field sensing apparatus 100 of fig. 1A employs the first, second, third and fourth magnetoresistive cells 110, 120, 130 and 140 and the first, second, third and fourth test wires 210, 220, 230 and 240 for sensing the magnetic field and self-correcting, however, in the magnetic field sensing apparatus 100b of the present embodiment, only the first and second magnetoresistive cells 110 and 120 and the first and second test wires 210 and 220 may be employed for sensing the magnetic field and self-correcting, and the first, second, third and fourth magnetoresistive cells 110, 120, 130 and 140 may be connected as a wheatstone bridge for sensing the magnetic field component in the second direction D2. Similar magnetic field sensing device 100a of fig. 6A may be modified to sense the magnetic field and self-correct using only the first and second magnetoresistive cells 110 and 120 and the first and second test conductive lines 210 and 220, and the first, second, third and fourth magnetoresistive cells 110, 120, 130 and 140 may be connected as at least one wheatstone bridge to sense the magnetic field components in the second direction D2 and the third direction D3.

Fig. 9 is a schematic top view of a test lead of a magnetic field sensing device according to still another embodiment of the invention. Referring to fig. 9, the magnetic field sensing device of the present embodiment has a plurality of sets of the first, second, third and fourth test wires 210, 220, 230, 240 as shown in fig. 1A, wherein the first and third test wires 210 and 230 of the sets of test wires are connected in series, and the second and fourth test wires 220 and 240 of the sets of test wires are connected in series. In addition, each set of the first, second, third and fourth test conductive lines 210, 220, 230 and 240 has the first, second, third and fourth magnetoresistive sensing units 110, 120, 130 and 140 above it, which are not shown in fig. 9. Such a magnetic field sensing device can also achieve the built-in self-test function of the magnetic field sensing device of FIG. 1A.

Fig. 10 is a schematic top view of a test lead of a magnetic field sensing device according to another embodiment of the invention. Referring to fig. 10, the magnetic field sensing device of the present embodiment has a plurality of sets of test conductive lines similar to the plurality of sets of test conductive lines of the magnetic field sensing device of fig. 9, and the difference between the sets of test conductive lines is that in the present embodiment, each set of test conductive lines further includes a fifth test conductive line 250 and a sixth test conductive line 260, which are similar to the third test conductive line 230 and the fourth test conductive line 240, respectively, wherein the first, third and fifth test conductive lines 210, 230 and 250 of each set of test conductive lines are connected in parallel, and the second, fourth and sixth test conductive lines 220, 240 and 260 of each set of test conductive lines are connected in parallel. In addition, the first, third, and fifth test conductive lines 210, 230, and 250 between the groups are connected in series, and the second, fourth, and sixth test conductive lines 220, 240, and 260 between the groups are also connected in series. In addition, a plurality of fifth magnetoresistive sensing units and a plurality of sixth magnetoresistive sensing units, which are similar to the first magnetoresistive sensing unit 110 and the second magnetoresistive sensing unit 120 respectively and are not shown in fig. 10, are also respectively disposed above each group of the fifth and sixth test wires 250 and 260. Such a magnetic field sensing device can also achieve the built-in self-test function of the magnetic field sensing device of FIG. 1A.

In summary, in the magnetic field sensing apparatus according to the embodiment of the invention, the first test wire and the second test wire are adopted, and the driver is used to enable the two currents in the same direction and the two currents in the opposite directions to flow through the first test wire and the second test wire at different times, so that the magnetic field sensing apparatus can be built in with a self-test function.

Finally, it should be noted that: the above embodiments are only used to illustrate the technical solution of the present invention, and not to limit the same; while the invention has been described in detail and with reference to the foregoing embodiments, it will be understood by those skilled in the art that: the technical solutions described in the foregoing embodiments may still be modified, or some or all of the technical features may be equivalently replaced; and the modifications or the substitutions do not make the essence of the corresponding technical solutions depart from the scope of the technical solutions of the embodiments of the present invention.