TW202009497A - Electric current sensor - Google Patents

Abstract

An electric current sensor including a substrate, a first sloped surface, a second sloped surface, at least one conductive wire, a first anisotropic magnetoresistor (AMR) unit, a second AMR unit, a first magnetization direction setting device, and a second magnetization direction setting device is provided. The first sloped surface and the second sloped surface are disposed on the substrate and arranged in the first direction. The conductive wire extends along the second surface and is disposed beside the substrate. The first AMR unit is disposed on the first sloped surface. The second AMR unit is disposed on the second sloped surface. The first magnetization direction setting device and the second magnetization direction setting device are configured to set magnetization directions of the AMR units.

Description

Current sensor

The invention relates to a sensor, and in particular to a current sensor.

Current sensing is one of the indispensable elements in industrial automation. In recent years, the demand for current sensing has expanded from industrial uses to consumer products and applications in smart homes and smart cities. High accuracy, fast response, small size, low power consumption and reliable quality have become the goals pursued by the new generation of current sensors.

There are currently many ways to measure the current in a conductor. For example, a shunt resistor can be used to calculate the current by measuring the voltage difference across it. However, the resistance phasor is small, so the current consumption is high, and it is not suitable for small or portable devices. In addition, high currents can generate heat and cause other problems.

The invention provides a current sensor with high sensitivity, high accuracy and low power consumption.

An embodiment of the present invention provides a current sensor, including a substrate, a first slope surface, a second slope surface, at least one wire, a first anisotropic magnetoresistive unit, and a second anisotropic magnetic The resistance unit, a first magnetization direction setting element and a second magnetization direction setting element. The first slope surface and the second slope surface are provided on the substrate and arranged in a first direction. The wire extends along a second direction and is disposed on one side of the substrate. The first anisotropic magnetoresistive unit is disposed on the first slope surface, and the second anisotropic magnetoresistive unit is disposed on the second slope surface. The first magnetization direction setting element is used to set the magnetization direction of the first anisotropic magnetoresistive unit, and the second magnetization direction setting element is used to set the magnetization direction of the second anisotropic magnetoresistive unit. When a current flows through the wire, a third-direction magnetic field component generated by the current at the first ramp surface is opposite to a third-direction magnetic field component generated by the current at the second ramp surface. The first direction, the second direction, and the third direction are different from each other, and the sensing directions of the first anisotropic magnetoresistive unit and the second anisotropic magnetoresistive unit are inclined with respect to the first direction and the third direction, and are different from Second direction. The first anisotropic magnetoresistive unit and the second anisotropic magnetoresistive unit are electrically connected to output a voltage signal. This voltage signal corresponds to the third-direction magnetic field component of the current generated at the first ramp surface and the second ramp surface.

In an embodiment of the invention, the current sensor further includes a third slope surface, a fourth slope surface, a third anisotropic magnetoresistive unit, and a fourth anisotropic magnetoresistive unit. The third slope surface and the fourth slope surface are provided on the substrate, wherein the third slope surface is opposite to the first slope surface, the fourth slope surface is opposite to the second slope surface, and the first slope surface, the third slope surface, and the fourth The slope surface and the second slope surface are sequentially arranged in the first direction. The third anisotropic magnetoresistive unit is disposed on the third slope surface, and the first magnetization direction setting element is also used to set the magnetization direction of the third anisotropic magnetoresistive unit. The fourth anisotropic magnetoresistive unit is disposed on the fourth slope surface, and the second magnetization direction setting element is also used to set the magnetization direction of the fourth anisotropic magnetoresistive unit. When current flows through the wire, due to the magnetic field induced by the current, the change in resistance value generated by the first anisotropic magnetoresistive unit is opposite to the change in resistance value generated by the third anisotropic magnetoresistive unit, and the second The change in resistance value generated by the anisotropic magnetoresistive unit is opposite to the change in resistance value generated by the fourth anisotropic magnetoresistive unit. The first, second, third and fourth anisotropic magnetoresistive units are electrically connected to form a Wheatstone bridge to output corresponding to the first, second, third and fourth anisotropic magnetoresistive units The voltage signal of the change of the resistance value.

In an embodiment of the invention, the current sensor further includes an arithmetic unit electrically connected to an output terminal of the Wheatstone bridge, wherein the first magnetization direction setting element and the second magnetization direction setting element , The second, third and fourth anisotropic magnetoresistive unit magnetization direction combination is set to a first combination, so that the Wheatstone bridge outputs a first voltage signal, and the first magnetization direction setting element and the first The second magnetization direction setting element sets the magnetization direction combination of the first, second, third, and fourth anisotropic magnetoresistive units to a second combination opposite to the first combination, so that the Wheatstone bridge outputs A second voltage signal. The arithmetic unit is used to subtract the second voltage signal from the first voltage signal to output an output voltage signal corresponding to the magnitude of the magnetic field generated by the current.

In an embodiment of the invention, the arithmetic unit is used to add the first voltage signal and the second voltage signal to output an offset voltage signal.

In an embodiment of the invention, the Wheatstone bridge corresponds to the voltage signal output by the external magnetic field component in the first direction being zero, and corresponds to the voltage output by the external magnetic field component in the second direction The signal is zero, and the voltage signal output corresponding to the external magnetic field component in the third direction is zero.

In an embodiment of the invention, the first anisotropic magnetoresistive unit includes a first anisotropic magnetic resistance and a second anisotropic magnetic resistance arranged in sequence along the reverse direction of the second direction, the second The anisotropic magneto-resistance unit includes a third anisotropic magneto-resistance and a fourth anisotropic magneto-resistance arranged in sequence along the reverse direction of the second direction. The third anisotropic magneto-resistance unit includes A fifth anisotropic magnetoresistance and a sixth anisotropic magnetoresistance are sequentially arranged in the opposite direction of the direction, and the fourth anisotropic magnetoresistance unit includes a first anisotropy sequentially arranged in the opposite direction of the second direction Seven anisotropic magnetoresistance and one eighth anisotropic magnetoresistance.

In an embodiment of the invention, at a first time, the first magnetization direction setting element sets the magnetization directions of the first anisotropic magnetoresistance and the fifth anisotropic magnetoresistance to the opposite direction of the second direction, and The magnetization directions of the second anisotropic magnetoresistance and the sixth anisotropic magnetoresistance are set as the second direction; at the first time, the second magnetization direction setting element sets the third anisotropic magnetoresistance and the seventh anisotropy The magnetization direction of the magnetoresistance is set to the opposite direction of the second direction, and the magnetization directions of the fourth and eighth anisotropic magnetoresistances are set to the second direction; at a second time, the first magnetization direction The setting element sets the magnetization directions of the first anisotropic magnetoresistance and the fifth anisotropic magnetoresistance to the second direction, and sets the magnetization directions of the second anisotropic magnetoresistance and the sixth anisotropic magnetoresistance to the first The opposite direction of the two directions; at the second time, the second magnetization direction setting element sets the magnetization directions of the third anisotropic magnetoresistance and the seventh anisotropic magnetoresistance to the second direction, and sets the fourth anisotropic magnetization The magnetization directions of the resistance and the eighth anisotropic magnetoresistance are set to be opposite to the second direction.

In an embodiment of the invention, the first magnetization direction setting element and the second magnetization direction setting element are conductive sheets, conductive coils, wires, conductors or permanent magnets.

In an embodiment of the invention, the first direction, the second direction and the third direction are perpendicular to each other.

In an embodiment of the invention, the at least one wire is a wire, the first slope surface and the second slope surface are located on a first side of the substrate, and the wire is located on a second side of the substrate, and the first side is opposite to The second side.

In an embodiment of the present invention, the first slope surface and the second slope surface are respectively located on one side of the opposite ends of the substrate, and the wires are located on the side of the center of the substrate.

In an embodiment of the present invention, the at least one wire is two wires, which are respectively disposed beside a first end and a second end of the substrate, wherein the first end is opposite to the second end, and the two wires are respectively Partially overlaps the first and second ends.

In an embodiment of the present invention, the at least one wire is two wires, which are respectively disposed beside a first end and a second end of the substrate, wherein the first end is opposite to the second end, and the two wires are respectively Does not overlap with the first and second ends.

In an embodiment of the present invention, the first anisotropic magnetoresistive unit and the second anisotropic magnetoresistive unit are electrically connected to form a Wheatstone bridge to output corresponding to the first anisotropic magnetoresistive unit and the first The voltage signal of the change of the resistance value generated by the two anisotropic magnetoresistive units.

In the current sensor of the embodiment of the present invention, since the anisotropic magnetoresistive unit is connected as a Wheatstone bridge to sense the magnetic field generated by the current in the wire, it is highly sensitive to current sensing Degree and high accuracy. In addition, since the current sensor of the embodiment of the present invention uses the magnetic field generated by the current to reverse the magnitude of the current, and the anisotropic magnetoresistive unit does not directly contact the current, it can have a lower Power consumption.

In order to make the above-mentioned features and advantages of the present invention more obvious and understandable, the embodiments are specifically described below in conjunction with the accompanying drawings for detailed description as follows.

FIG. 1 is a schematic top view of a current sensor according to an embodiment of the invention, and FIG. 2 is a schematic cross-sectional view of the current sensor of FIG. 1 along line A-A. 1 and 2, the current sensor 100 of this embodiment includes a substrate 210, a first slope surface S1, a second slope surface S2, and at least one wire C (in FIG. 1, a wire C is used as Example), a first anisotropic magnetoresistive unit 222, a second anisotropic magnetoresistive unit 224, a first magnetization direction setting element M1 and a second magnetization direction setting element M2. The first slope surface S1 and the second slope surface S2 are disposed on the substrate 210 and are arranged in a first direction D1. The wire C extends along a second direction D2 and is disposed on one side of the substrate 210. In this embodiment, an insulating layer 215 is provided on the substrate 210, and the first slope surface S1 and the second slope surface S2 are the surfaces of the insulation layer 215. However, in other embodiments, the first slope surface S1 and the second slope surface S2 may also be the surface of the substrate 210.

The wire C extends along a second direction D2 and is disposed on one side of the substrate 210. In this embodiment, the first slope surface S1 and the second slope surface S2 are located on a first side of the substrate 210 (ie, the upper side in FIG. 2 ), and the wire C is located on a second side of the substrate 210 (ie, in FIG. 2) The lower side), where the first side is opposite to the second side. In addition, the insulating layer 215 is located on the first side of the substrate 210. In this embodiment, the first slope surface S1 and the second slope surface S2 are respectively located on one side (eg, the first side) of the opposite ends (ie, the first end 212 and the second end 214) of the substrate 210, and the wire C Located on the side of the center of the substrate 210 (for example, the second side). In addition, in this embodiment, the distance from the wire C to the first slope surface S1 may be equal to the distance from the wire C to the second slope surface S2.

The first anisotropic magnetoresistive unit 222 is disposed on the first slope surface S1, and the second anisotropic magnetoresistive unit 224 is disposed on the second slope surface S2. The first magnetization direction setting element M1 is used to set the magnetization direction of the first anisotropic magnetoresistive unit 222. The second magnetization direction setting element M2 is used to set the magnetization direction of the second anisotropic magnetoresistive unit 224.

When a current I flows through the wire C, the magnetic field component HC in the third direction D3 generated by the current I at the first ramp surface S1 (ie, the magnetic field component HC in the upper left corner of FIG. 2) is opposite to the current I on the second ramp The magnetic field component HC in the third direction D3 generated at the surface S2 (that is, the magnetic field component HC in the upper right corner of FIG. 2). The first direction D1, the second direction D2, and the third direction D3 are different from each other, and the sensing directions 312 of the first anisotropic magnetoresistive unit 222 and the second anisotropic magnetoresistive unit 224 are relative to the first direction D1 and the first The three directions D3 are inclined and are different from the second direction D2. The first anisotropic magnetoresistive unit 222 and the second anisotropic magnetoresistive unit 224 are electrically connected to output a voltage signal. This voltage signal corresponds to the magnetic field component HC in the third direction D3 generated by the current I at the first ramp surface S1 and the second ramp surface S2.

The space where the current sensor 100 exists can be constructed by the first direction D1, the second direction D2, and the third direction D3 that are different from each other. In this embodiment, the first direction D1, the second direction D2, and the third direction D3 can be perpendicular to each other. However, in other embodiments, the first direction D1, the second direction D2, and the third direction D3 may not be perpendicular to and different from each other. In this embodiment, the third direction D2 is a direction from the second side of the substrate 210 (ie, the lower side in FIG. 2) to the first side of the substrate 210 (ie, the upper side in FIG. 2 ).

In this embodiment, the current sensor further includes a third slope surface S3, a fourth slope surface S4, a third anisotropic magnetoresistive unit 226, and a fourth anisotropic magnetoresistive unit 228. The third slope surface S3 and the fourth slope surface S4 are provided on the substrate 210, wherein the third slope surface S3 is opposite to the first slope surface S1, the fourth slope surface S4 is opposite to the second slope surface S2, and the first slope surface S1 , The third slope surface S3, the fourth slope surface S4 and the second slope surface S2 are sequentially arranged in the first direction D1. In this embodiment, the third slope surface S3 and the fourth slope surface S4 are the surfaces of the insulating layer 215. That is, the insulating layer 215 has two grooves, the first slope surface S1 and the third slope surface S3 are the two inclined sidewalls of one of the grooves, and the second slope surface S2 and the fourth slope surface S4 are the other concave Two inclined side walls of the groove. However, in other embodiments, the substrate 210 may have two grooves, and the first to fourth slopes S1, S2, S3, and S4 are inclined sidewalls of the groove of the substrate 210.

The third anisotropic magnetoresistive unit 226 is disposed on the third slope surface S3, and the first magnetization direction setting element M1 is also used to set the magnetization direction of the third anisotropic magnetoresistive unit 226. The fourth anisotropic magnetoresistive unit 228 is disposed on the fourth slope surface S4, and the second magnetization direction setting element M2 is also used to set the magnetization direction of the fourth anisotropic magnetoresistive unit 228. When the current I flows through the wire C, due to the magnetic field HC induced by the current I, the resistance value generated by the first anisotropic magnetoresistive unit 222 changes contrary to the resistance generated by the third anisotropic magnetoresistive unit 226 Value changes, and the change in resistance value generated by the second anisotropic magnetoresistive unit 224 is opposite to the change in resistance value generated by the fourth anisotropic magnetoresistive unit 228, and the first, second, third, and fourth The directional magnetoresistive units 222, 224, 226, and 228 are electrically connected to form a Wheatstone bridge to output corresponding to the first, second, third, and fourth anisotropic magnetoresistive units 222, 224, 226, and 228 The resulting voltage signal changes in resistance.

In this embodiment, the first anisotropic magnetoresistive unit 222 includes a first anisotropic magnetoresistor (AMR) R1 and a second anisotropy arranged in sequence along the reverse direction of the second direction D2 Magnetoresistance R2, the second anisotropic magnetoresistive unit 224 includes a third anisotropic magnetoresistor R3 and a fourth anisotropic magnetoresistance R4 arranged in sequence along the reverse direction of the second direction D2, the third The anisotropic magneto-resistance unit 226 includes a fifth anisotropic magneto-resistance R5 and a sixth anisotropic magneto-resistance R6 sequentially arranged along the reverse direction of the second direction D2, and a fourth anisotropic magneto-resistance unit 228 includes a seventh anisotropic magnetoresistance R7 and an eighth anisotropic magnetoresistance R8 arranged in sequence along the reverse direction of the second direction D2. The numbers of the first to eighth anisotropic magnetoresistances R1 to R8 are each taken as an example. However, in other embodiments, each anisotropic magnetoresistance may also use a plurality of anisotropies connected in series. Magnetoresistance to replace. For example, the first anisotropic magnetoresistance R1 can be replaced with a plurality of first anisotropic magnetoresistance R1 connected in series.

In this embodiment, the first magnetization direction setting element M1 and the second magnetization direction setting element M2 and the first to fourth anisotropic magnetoresistive units 222, 224, 226, and 228 may be disposed on the substrate 210, and the magnetization direction The setting element and the anisotropic magnetoresistive unit can be separated by an insulating layer. In this embodiment, the first magnetization direction setting element M1 is disposed below the first and third anisotropic magnetoresistive units 222 and 226, and the second magnetization direction setting element M2 is disposed between the second and fourth anisotropic magnetism Below the resistance units 224, 228. However, in other embodiments, the first magnetization direction setting element M1 may be disposed above the first and third anisotropic magnetoresistive units 222, 226, and the second magnetization direction setting element M2 may be disposed between the second and second The four anisotropic magnetoresistive units 224 and 228 are arranged above. Alternatively, in other embodiments, the first magnetization direction setting element M1 may also be distributed on both the upper and lower sides of the first and third anisotropic magnetoresistive units 222 and 226, and the second magnetization direction setting element M2 It may be distributed on both the upper and lower sides of the second and fourth anisotropic magnetoresistive units 224 and 228.

In addition, the wire C may be covered by a package body 120, and both ends of the wire C are exposed outside the package body 120, wherein the package body 120 is made of an insulating material, for example. The substrate 210 can be disposed on the package body 120. In this embodiment, the wire C extends along the second direction D2.

3A and 3B are used to explain the operation principle of the anisotropic magnetoresistance in FIG. 1. Please refer to FIG. 3A first, the anisotropic magnetoresistance 300 has a barber pole (barber pole)-like structure, that is, the surface is provided with a plurality of short-circuit rods inclined by 45 degrees with respect to the extension direction D of the anisotropic magnetoresistance 300 (Electrical shorting bar) 310, these short-circuit bars 310 are spaced apart from each other and are arranged in parallel on a ferromagnetic film (ferromagnetic film) 320, and the ferromagnetic film 320 is the main body of the anisotropic magnetoresistance 300, and its extending direction is different The extending direction D of the directional magnetoresistance 300. In addition, the opposite ends of the ferromagnetic film 320 can be made into a pointed shape.

Before the measurement of the external magnetic field H, the anisotropic magnetoresistance 300 can be set by the magnetization direction setting element (such as the first magnetization direction setting element M1 or the second magnetization direction setting element M2 of FIG. 1) The magnetization direction setting element is, for example, a coil, a wire, a metal sheet, or a conductor that can generate a magnetic field by energization. In FIG. 3A, the magnetization direction setting element can generate a magnetic field along the extending direction D by energization, so that the anisotropic magnetoresistance 300 has the magnetization direction M.

Next, the magnetization direction setting element is not energized, so that the anisotropic magnetoresistance 300 starts to measure the external magnetic field H. When there is no external magnetic field H, the magnetization direction M of the anisotropic magneto-resistance 300 is maintained in the extension direction D. At this time, a current i is applied, so that the current i flows from the left end to the right end of the anisotropic-magnetism resistance 300, then short circuit The flow direction of the current i near the bar 310 is perpendicular to the extending direction of the short-circuit bar 310, so that the current i near the short-circuit bar 310 flows at 45 degrees to the magnetization direction M. At this time, the resistance value of the anisotropic magnetoresistance 300 is R.

When an external magnetic field H is oriented perpendicular to the extension direction D, the magnetization direction M of the anisotropic magnetoresistance 300 will be deflected in the direction of the external magnetic field H, so that the angle between the magnetization direction and the current i flowing near the short-circuit bar is greater than At 45 degrees, the resistance value of the anisotropic magnetoresistance 300 changes by -ΔR, which becomes R-ΔR, that is, the resistance value becomes smaller, where ΔR is greater than 0.

However, as shown in FIG. 3B, when the extending direction of the short-circuit bar 310 of FIG. 3B is set at a direction 90 degrees from the extending direction of the short-circuit bar 310 of FIG. 3A (at this time, the extending direction of the short-circuit bar 310 of FIG. 3B is still 45 degrees with the extension direction D of the anisotropic magnetoresistance 300), and when there is an external magnetic field H, in addition to the magnetic field H will still deflect the magnetization direction M to the direction of the external magnetic field H, at this time the magnetization direction M and short circuit The included angle of the current i flowing near the rod 310 will be less than 45 degrees, so that the resistance value of the anisotropic magnetoresistance 300 becomes R+ΔR, that is, the resistance value of the anisotropic magnetoresistance 300 becomes larger.

In addition, when the magnetization direction setting element sets the magnetization direction M of the anisotropic magnetoresistance 300 to the reverse direction shown in FIG. 3A, the resistance value of the anisotropic magnetoresistance 300 of FIG. 3A under the external magnetic field H will be It becomes R+ΔR. In addition, when the magnetization direction setting element sets the magnetization direction M of the anisotropic magnetoresistance 300 to the reverse direction shown in FIG. 3B, the resistance value of the anisotropic magnetoresistance 300 of FIG. 3B under the external magnetic field H is thereafter Will become R-ΔR.

In summary, when the setting direction of the short-circuit bar 310 changes, the resistance value R of the anisotropic magnetoresistance 300 corresponding to the change of the external magnetic field H will change from +ΔR to -ΔR or vice versa, and when the magnetization direction setting element When the set magnetization direction M is changed to the reverse direction, the resistance value R of the anisotropic magnetoresistive 300 changes from +ΔR to −ΔR or vice versa according to the change in the external magnetic field H. When the direction of the external magnetic field H becomes reverse, the resistance value R of the anisotropic magnetic resistance 300 corresponding to the change of the external magnetic field H will change from +ΔR to −ΔR or vice versa. However, when the current i passing through the anisotropic magnetoresistance 300 becomes reverse, the resistance value R of the anisotropic magnetoresistance 300 corresponds to the change of the external magnetic field H and maintains the same sign as the original, that is, if it is originally +ΔR After changing the current direction, it is still +ΔR. If it was originally -ΔR, it is still -ΔR after changing the current direction.

According to the above principle, the anisotropy can be determined by designing the extension direction of the shorting bar 310 or the magnetization direction M set by the magnetization direction setting element when the anisotropic magnetoresistance 300 receives a certain component of the external magnetic field H The direction of change of the resistance value R of the magnetoresistance 300, that is, the resistance value R becomes larger or smaller, for example, the amount of change is +ΔR or -ΔR. In addition, the direction perpendicular to the extending direction D of the anisotropic magnetoresistance 300 is the sensing direction of the anisotropic magnetoresistance 300 (like the sensing direction 312 in FIGS. 1 and 2 ), that is, in FIGS. 3A and 3B The direction parallel to the external magnetic field H.

4A and 4B respectively illustrate the magnetization direction of the anisotropic magnetoresistance of the current sensor of FIG. 1 at the first time and the second time and the change of the resistance value afterwards, and show the first to eighth differences The extending direction of the short-circuit bars in the directional magnetoresistances R1 to R8. Please refer to FIGS. 4A and 4B. In this embodiment, the extending directions of the first to eighth anisotropic magnetoresistances R1 to R8 are all the second direction D2, and the extending direction of the shorting bar 310 is as shown in FIG. 4A It is shown that in the first and fourth anisotropic magnetoresistive units 222 and 228, the shorting bars 310 of the first, second, seventh and eighth anisotropic magnetoresistive resistors R1, R2, R7 and R8 are respectively in two The two different directions are 45 degrees from the second direction D2, and the two different directions are parallel to the first slope surface S1 and the fourth slope surface S4. In addition, in the second and third anisotropic magnetoresistive units 224 and 226, the shorting bars 310 of the third, fourth, fifth and sixth anisotropic magnetoresistive resistors R3, R4, R5 and R6 are respectively in the other two The two different directions are 45 degrees from the second direction D2, and the two different directions are parallel to the second slope surface S2 and the third slope surface S3. In this embodiment, the first slope surface S1 is parallel to the fourth slope surface S4, the second slope surface S2 is parallel to the third slope surface S3, and the first slope surface S1 and the second slope surface S2 are respectively inclined in different directions .

When the wire C is supplied with the current I (as shown in FIGS. 1, 2, 4A, and 4B), the direction of the current I in the wire C is, for example, the second direction D2. At this time, the current I generates a magnetic field component HC along the third direction D3 on the first, second, fifth, and sixth anisotropic magnetoresistances R1, R2, R5, and R6, and the current I is in the third, 4. The seventh and eighth anisotropic magnetoresistances R3, R4, R7, and R8 generate a magnetic field component HC in the reverse direction of the third direction D3. In addition, in this embodiment, when the current I flows through the wire C, the current I is at the first slope surface S1 and the third slope surface S3 (ie, the first anisotropic magnetoresistive unit 222 and the third anisotropy Magnetoresistive unit 226) the component of the magnetic field in the third direction D3 (ie, the magnetic field component HC on the left in FIGS. 2, 4A, and 4B, which faces the third direction D3) is opposite to the current I in the third The components of the magnetic field in the third direction D3 generated by the second ramp surface S2 and the fourth ramp surface S4 (that is, at the second anisotropic magnetoresistive unit 224 and the fourth anisotropic magnetoresistive unit 228) 2. The magnetic field component HC on the right in FIGS. 4A and 4B faces the direction opposite to the third direction D3).

At a first time, the first magnetization direction setting element M1 sets the magnetization directions M15 of the first anisotropic magnetoresistance R1 and the fifth anisotropic magnetoresistance R5 to the opposite direction of the second direction D2, and sets the second anisotropy The magnetization directions M26 of the anisotropic magnetoresistance R2 and the sixth anisotropic magnetoresistance R6 are set to the second direction D2. In addition, at the first time, the second magnetization direction setting element M2 sets the magnetization directions M37 of the third anisotropic magnetoresistance R3 and the seventh anisotropic magnetoresistance R7 to the opposite direction of the second direction D2, and sets the fourth The magnetization directions M48 of the anisotropic magneto resistance R4 and the eighth anisotropic magneto resistance R8 are set to the second direction D2. In this embodiment, the first magnetization direction setting element M1 and the second magnetization direction setting element M2 are, for example, conductive coils, wires, conductive sheets (such as metal sheets) or conductors that can generate a magnetic field by energization, as long as they can generate The conductive structures of the magnetic fields with the magnetization directions M15, M26, M37, and M48 can be used as the first magnetization direction setting element M1 and the second magnetization direction setting element M2.

After the first time, the first magnetization direction setting element M1 and the second magnetization direction setting element M2 will stop generating magnetic fields, for example, the first magnetization direction setting element M1 and the second magnetization direction setting element M2 are no longer generated by passing current Magnetic field, at this time, the first, second, fifth and sixth anisotropic magnetoresistances R1, R2, R5 and R6 can induce the magnetic field component HC generated by the current I (Figure 2, Figure 4A and Figure 4B left Square magnetic field component HC) and the resistance value changes of +ΔR, +ΔR, -ΔR and -ΔR, respectively, and the third, fourth, seventh and eighth anisotropic magnetoresistances R3, R4, R7 and R8 The resistance value of -ΔR, -ΔR, +ΔR, and +ΔR can be induced by the magnetic field component HC (the magnetic field component HC on the right in FIGS. 2, 4A, and 4B) generated by the current I, respectively.

In this embodiment, the first anisotropic magneto resistance R1, the second anisotropic magneto resistance R2, the third anisotropic magneto resistance R3 and the fourth anisotropic magneto resistance R4 can be serially connected from the contact P1 to The contact P2 and the contact P3 can be electrically connected to the conductive path between the second anisotropic magneto-resistance R2 and the fourth anisotropic magneto-resistance R4, the fifth anisotropic magneto-resistance R5 and the sixth anisotropic magneto The resistor R6 may be serially connected from the contact P1 to the contact P4, and the seventh anisotropic magnetic resistance R7 and the eighth anisotropic magnetic resistance R8 may be serially connected from the contact P2 to the contact P5. The contact P3 can receive the reference voltage VDD, and the contact P4 and the contact P5 can be coupled to the ground. The voltage difference between the contact P1 and the contact P2 in the Wheatstone bridge formed at this time will be (VDD)×(-ΔR/R), which can be an output signal. The output signal is a differential signal, the magnitude of which corresponds to the magnitude of the magnetic field component HC, and then the magnitude of the current I flowing through the wire C, and thereafter This output signal is referred to as the first voltage signal V ₁ . In another embodiment, the contact P3 may be coupled to ground, and the contact P4 and the contact P5 receive the reference voltage VDD.

At a second time thereafter, the first magnetization direction setting element M1 sets the magnetization directions M15′ of the first anisotropic magnetoresistance R1 and the fifth anisotropic magnetoresistance R5 to the second direction D2, and sets the second The magnetization directions M26' of the anisotropic magnetoresistance R2 and the sixth anisotropic magnetoresistance R6 are set to be opposite to the second direction D2. In addition, at the second time, the second magnetization direction setting element M2 sets the magnetization directions M37′ of the third anisotropic magnetoresistance R3 and the seventh anisotropic magnetoresistance R7 to the second direction D2, and sets the fourth anisotropy The magnetization directions M48' of the magneto-resistance R4 and the eighth anisotropic magneto-resistance R8 are set to be opposite to the second direction D2.

After the second time, the first magnetization direction setting element M1 and the second magnetization direction setting element M2 stop generating magnetic fields. At this time, the first, second, fifth, and sixth anisotropic magnetoresistances R1, R2, R5 R6 and R6 can induce the magnetic field component HC generated by the current I to produce resistance changes of -ΔR, -ΔR, +ΔR and +ΔR, and the third, fourth, seventh and eighth anisotropic magnetoresistance R3, R4, R7, and R8 can induce the magnetic field component HC generated by the current I to generate resistance changes of +ΔR, +ΔR, -ΔR, and -ΔR, respectively. The voltage difference between the contact P1 and the contact P2 in the Wheatstone bridge formed at this time will be (VDD)×(ΔR/R), which can be the output signal, and the output signal is a differential signal, the size of which It will correspond to the magnitude of the magnetic field component HC, and then to the magnitude of the current I flowing through the wire C. Hereinafter, this output signal will be referred to as the second voltage signal V ₂ .

FIG. 5 is an output voltage-current curve diagram of the Wheatstone bridge of FIGS. 4A and 4B, and FIG. 6 illustrates that the Wheatstone bridge of FIGS. 4A and 4B is coupled to an arithmetic unit. Please refer to FIG. 4A, FIG. 4B, FIG. 5 and FIG. 6, in this embodiment, the current sensor 100 further includes an arithmetic unit 400, which is electrically connected to an output terminal of the Wheatstone bridge (ie, receives the first Voltage signal V ₁ and second voltage signal V ₂ ), wherein the first magnetization direction setting element M1 and the second magnetization direction setting element M2 divide the first, second, third and fourth anisotropic magnetoresistive units 222, 224 , 226, and 228 are set to a first combination of magnetization directions (ie, the combination of magnetization direction M15, magnetization direction M26, magnetization direction M37, and magnetization direction M48 as shown in FIG. 4A), so that the Wheatstone bridge outputs the first Voltage signal V ₁ , and the first magnetization direction setting element M1 and the second magnetization direction setting element M2 then convert the magnetization directions of the first, second, third, and fourth anisotropic magnetoresistive units 222, 224, 226, and 228 The combination is set to a second combination opposite to the first combination (ie, the combination of the magnetization direction M15′, the magnetization direction M26′, the magnetization direction M37′, and the magnetization direction M48′ as shown in FIG. 4B), so that after the Wheatstone bridge The second voltage signal V _{2 is} output. The operator 400 is used to subtract the second voltage signal V ₂ from the first voltage signal V ₁ to output an output voltage signal V _out corresponding to the magnitude of the magnetic field generated by the current I. In addition, in this embodiment, the arithmetic unit 400 can also be used to add the first voltage signal V ₁ and the second voltage signal V ₂ to output an offset voltage signal V _off .

Specifically, the operator 400 may include an arithmetic operator 410 and an arithmetic operator 420, wherein the arithmetic operator 410 is, for example, an adder, which is used to phase the first voltage signal V ₁ and the second voltage signal V ₂ Add to output the offset voltage signal V _off . In addition, the arithmetic operator 420 is, for example, a subtractor for subtracting the second voltage signal V ₂ and the first voltage signal V ₁ to output an output voltage signal V _out corresponding to the magnitude of the magnetic field generated by the current I .

As can be seen from FIG. 5, the output voltage-current curve of the Wheatstone bridge may have an offset voltage signal V _off , and the offset voltage may be left after the first voltage signal V ₁ and the second voltage signal V ₂ are added. After the signal V _off and the second voltage signal V ₂ and the first voltage signal V ₁ are subtracted, the output voltage-current curve will pass through the point where both the voltage and the current are zero, making the voltage and current almost within a certain range It is proportional to the resistance value change ΔR can be accurately estimated by the output voltage signal V _out .

In this embodiment, the contacts P1 to P5 and the arithmetic unit 400 are, for example, present in the substrate 210, and the substrate 210 is a circuit substrate, for example, a semiconductor substrate.

FIG. 7 illustrates the change of the resistance value of the current sensor of FIG. 1 when the magnetization direction of the anisotropic magnetoresistance and the external magnetic field components in three different directions are followed, and FIGS. 8 and 9 are respectively FIG. 1 shows the change of the resistance value of the current sensor of FIG. 1 at the second time when the magnetization direction of the anisotropic magnetoresistance and the subsequent external magnetic field components in three different directions are received. Please refer to FIG. 7 first, after the first magnetization direction setting element M1 and the second magnetization direction setting element M2 complete the setting of the magnetization directions M15, M26, M37, M48 at the first time, when there is an external direction along the first direction D1 When the magnetic field component HE1 is present, the resistance value changes generated by the first to eighth anisotropic magnetoresistances R1 to R8 are -ΔR, -ΔR, +ΔR, +ΔR, -ΔR, -ΔR, +ΔR, and +ΔR In this way, when the contact P3 receives the reference voltage VDD and the contact P4 and the contact P5 are coupled to ground, the voltage difference between the contact P1 and the contact P2 in the Wheatstone bridge formed at this time Will be zero.

8 again, after the first magnetization direction setting element M1 and the second magnetization direction setting element M2 complete the setting of the magnetization directions M15', M26', M37', and M48' at the second time, when one of them is along the second direction When the external magnetic field component HE2 of D2 exists, the resistance value changes of the first to eighth anisotropic magnetoresistances R1 to R8 are all zero, because the second direction D2 is not the first to eighth anisotropy magnetism The direction that resistors R1～R8 can sense. In this way, when the contact P3 receives the reference voltage VDD, and the contact P4 and the contact P5 are coupled to ground, the voltage difference between the contact P1 and the contact P2 in the Wheatstone bridge formed at this time will be Is zero.

9 again, after the first magnetization direction setting element M1 and the second magnetization direction setting element M2 complete the setting of the magnetization directions M15', M26', M37', and M48' at the second time, when one of them is along the third direction When the external magnetic field component HE3 of D3 is present, the resistance values generated by the first to eighth anisotropic magnetoresistances R1 to R8 are -ΔR, -ΔR, -ΔR, -ΔR, +ΔR, +ΔR, + ΔR and +ΔR. In this way, when the contact P3 receives the reference voltage VDD, and the contact P4 and the contact P5 are coupled to ground, the voltage difference between the contact P1 and the contact P2 in the Wheatstone bridge formed at this time will be Is zero.

That is to say, in this embodiment, the Wheatstone bridge corresponds to the external magnetic field component HE1 in the first direction D1 and the voltage signal output by the HE1 is zero, corresponding to the external magnetic field component in the second direction D2 The voltage signal output by HE2 is zero, and the voltage signal output by HE3 corresponding to the external magnetic field component in the third direction D3 is zero. Therefore, no matter which direction the external magnetic field is in, it will not affect the sensing result of the current sensor 100 of this embodiment, that is, it will not interfere with the output voltage of the current sensor 100.

The response of the above Wheatstone bridge to the external magnetic field component HE1 is based on the reaction after the first time, while the response of the above Wheatstone bridge to the external magnetic field components HE2 and HE3 is after the second time For example, after the second time, the first magnetization direction setting element M1 and the second magnetization direction setting element M2 complete the magnetization directions M15', M26', M37', and M48' of FIG. 4B at the second time. After setting, the first to eighth anisotropic magnetoresistances R1 to R8 react to the external magnetic field component HE1, and the resistance value changes are +ΔR, +ΔR, -ΔR, -ΔR, +ΔR, +ΔR,- ΔR and -ΔR, in this way, when the contact P3 receives the reference voltage VDD, and the contact P4 and the contact P5 are coupled to the ground, the contact P1 and the contact P2 of the Wheatstone bridge formed at this time The voltage difference between them will be zero. After the first magnetization direction setting element M1 and the second magnetization direction setting element M2 complete the setting of the magnetization directions M15, M26, M37, and M48 as shown in FIG. 4A at the first time, for the external magnetic field component HE2, the first to the first The eight anisotropic magnetoresistances R1～R8 will not be affected by them, so there will be no change in resistance value, so the voltage difference between the contact P1 and the contact P2 in the Wheatstone bridge will still be zero; The external magnetic field component HE3, the first to the eighth anisotropic magnetoresistances R1 to R8 react to the external magnetic field component HE3 and the resistance value changes are +ΔR, +ΔR, +ΔR, +ΔR, -ΔR,- ΔR, -ΔR, and -ΔR, so that when the contact P3 receives the reference voltage VDD and the contact P4 and the contact P5 are coupled to ground, the contact P1 and the contact of the Wheatstone bridge formed at this time The voltage difference between points P2 will be zero. Therefore, no matter after the first time or the second time, the current sensor 100 of this embodiment will not be disturbed by the external magnetic field in any direction.

In addition, a feedback coil may be provided in or on the substrate 210, which at least partially overlaps the first to eighth anisotropic magnetoresistances R1 to R8 to serve as a close-loop control (close-loop control) the use of.

10 is a schematic top view of a current sensor according to another embodiment of the invention. Please refer to FIG. 10, the current sensor 100 a of this embodiment is similar to the current sensor 100 of FIGS. 1, 2, 4A, and 4B, and the differences between the two are as follows. In this embodiment, both the first magnetization direction setting element M1a and the second magnetization direction setting element M2a of the current sensor 100a are permanent magnets, wherein the first magnetization direction setting element M1a is used to combine the first, second, and second The magnetization directions of the fifth and sixth anisotropic magnetoresistances R1, R2, R5, and R6 are set to the magnetization direction M1256, which points in the opposite direction of the second direction D2, and the second magnetization direction setting element M2a is used 4. The magnetization directions of the seventh and eighth anisotropic magnetoresistances R3, R4, R7, and R8 are set to the magnetization direction M3478, which points in the opposite direction of the second direction D2.

In addition, the extending directions of the shorting bars of the first, third, fifth, and seventh anisotropic magnetoresistances R1, R3, R5, and R7 may be the same as the first, third, fifth, and seventh in FIG. 4A The anisotropic magnetoresistance R1, R3, R5 and R7 extend the direction of the short-circuit bar, and unlike FIG. 4A, in this embodiment, the extension direction of the short-circuit bar of the second anisotropic magnetoresistance R2 is the same as the The extension direction of the short-circuit bar of an anisotropic magneto-resistance R1, the extension direction of the short-circuit bar of the fourth anisotropy-resistance R4 is the same as the extension direction of the short-circuit bar of the third anisotropy-resistance R3, the sixth anisotropy The extending direction of the short-circuit bar of the magneto-resistance R6 is the same as the extending direction of the short-circuit bar of the fifth anisotropic magneto-resistance R5, and the extending direction of the short-circuit bar of the eighth anisotropic magneto-resistance R8 is the same as the seventh anisotropic magneto-resistance The extension direction of the shorting bar of R7.

In this way, when the current I flows through the wire C, the Wheatstone bridge connected by the first to eighth anisotropic magnetoresistances R1 to R8 can also output the corresponding voltage signal.

11 is a schematic top view of a current sensor according to another embodiment of the invention. Referring to FIG. 11, the current sensor 100 b of this embodiment is similar to the current sensor 100 of FIG. 4A, and the difference between the two is as follows. The current sensor 100b of this embodiment includes a first anisotropic magnetoresistive unit 222 and a second anisotropic magnetoresistive unit 224, but does not include the third anisotropic magnetoresistive unit 226 and the fourth anisotropic magnetoresistive unit as shown in FIG. 4A. Directional magnetoresistive unit 228.

In this embodiment, the extending direction of the short-circuit bar 310 of the first anisotropic magnetoresistance R1 is the same as the extending direction of the short-circuit bar 310 of the first anisotropic magneto-resistance R1 in FIG. 4A, and the third anisotropic magnetism The extending direction of the short-circuit bar 310 of the resistor R3 is the same as the extending direction of the short-circuit bar 310 of the third anisotropic magnetoresistance R3 in FIG. 4A. However, the difference from FIG. 4A is that, in this embodiment, the extending direction of the short-circuit bar 310 of the second anisotropic magnetoresistance R2 is the same as the extending direction of the short-circuit bar 310 of the first anisotropic magneto-resistance R1, and The extending direction of the short-circuit bar 310 of the fourth anisotropic magnetoresistance R4 is the same as the extending direction of the short-circuit bar 310 of the third anisotropic magneto-resistance R3.

In addition, at the first time, the first magnetization direction setting element M1 sets the magnetization direction of the first anisotropic magnetoresistance R1 to the magnetization direction M10, which points in the opposite direction of the second direction D2; the first magnetization direction setting element M1 will The magnetization direction of the second anisotropic magnetoresistance R2 is set to the magnetization direction M20, which points to the second direction D2; the second magnetization direction setting element M2 sets the magnetization direction of the third anisotropic magnetoresistance R3 to the magnetization direction M30, which It points in the opposite direction of the second direction D2; the second magnetization direction setting element M2 sets the magnetization direction of the fourth anisotropic magnetoresistance R4 as the magnetization direction M40, which points in the second direction D2. In this way, after the first time, when the current I flows through the wire C, and when the third contact P3' and the fourth contact P4' receive the reference voltage VDD, the fifth contact P5' and the sixth contact When point P6' is coupled to ground, the resistance values of the first to fourth anisotropic magnetoresistances R1, R2, R3, and R4 will be +ΔR, -ΔR, -ΔR, +ΔR, respectively. The voltage difference between the point P1' and the second contact P2' will be (VDD)×(-ΔR/R), which can be an output signal, and the output signal is a differential signal, the magnitude of which corresponds to the magnetic field component HC The magnitude of, in turn, corresponds to the magnitude of the current I flowing through the wire C. Similarly, at the second time, when the first magnetization direction setting element M1 and the second magnetization direction setting element M2 set the magnetization directions of the first to fourth anisotropic magnetoresistances R1 to R4 to be opposite to those of FIG. 11 When combined, the voltage difference between the first contact P1' and the second contact P2' will be (VDD) × (+ΔR/R).

In this embodiment, the first anisotropic magnetoresistance R1 and the second anisotropic magnetoresistance R2 are connected in series from the third contact P3' to the fifth contact P5' in sequence, and the third anisotropic magnetoresistance R3 and The fourth anisotropic magnetoresistance R4 is serially connected from the fourth contact P4' to the sixth contact P6', and the first contact P1' is coupled to the first anisotropic magnetoresistance R1 and the second anisotropic magnetism The conductive path between the resistors R2, and the second contact P2' is coupled to the conductive path between the third anisotropic magnetic resistor R3 and the fourth anisotropic magnetic resistor R4.

In other words, in this embodiment, the first anisotropic magnetoresistive unit 222 and the second anisotropic magnetoresistive unit 224 are electrically connected to form a Wheatstone bridge to output corresponding to the first anisotropic resistance unit 222 and The voltage signal of the resistance value generated by the second anisotropic resistance unit 224 changes.

FIG. 12A is a schematic top view of a current sensor according to still another embodiment of the present invention, and FIG. 12B is a schematic cross-sectional view of the current sensor of FIG. 12A along line A1-A1. 12A and 12B, the current sensor 100c of this embodiment is similar to the current sensor 100 of FIGS. 1 and 2, and the difference between the two is as follows. In this embodiment, the current sensor 100c has two wires C1 and C2, which are respectively disposed beside the first end 212 and the second end 214 of the substrate, wherein the first end 212 is opposite to the second end 214, and two The wires C1 and C2 do not overlap with the first end 212 and the second end 214, respectively. In this embodiment, the wires C1 and C2 both extend along the second direction D2. When the currents I1 and I2 flow respectively through the wire C1 and the wire C2 along the opposite direction of the second direction D2, the current I1 generates a magnetic field component HC directed to the third direction D3 at the first slope surface S1 and the third slope surface S3 And the current I2 will generate a magnetic field component HC directed in the opposite direction of the third direction D3 at the second slope surface S2 and the fourth slope surface S4. In this way, the Wheatstone bridge connected by the first to fourth anisotropic magnetoresistive units 222, 224, 226, and 228 can output a voltage signal corresponding to the magnitude of the current I1 and the current I2. In this embodiment, the magnitude and direction of the current I1 are the same as the magnitude and direction of the current I2.

The present invention does not limit the number of wires in the current sensor 100c. In other embodiments, the wires in the current sensor 100c may be more than two.

13A is a schematic top view of a current sensor according to another embodiment of the invention, and FIG. 13B is a schematic cross-sectional view of the current sensor of FIG. 13A along line A2-A2. 13A and 13B, the current sensor 100d of this embodiment is similar to the current sensor 100c of FIGS. 12A and 12B, and the difference between the two is as follows. In the current sensor 100d of this embodiment, the wires C1 and C2 partially overlap the first end 212 and the second end 214 of the substrate 210, respectively, so that they can still be at the first slope surface S1 and the third slope surface S3 A magnetic field component HC directed to the third direction D3 is generated, and a magnetic field component directed to the opposite direction of the third direction D3 can be generated at the second ramp surface S2 and the fourth ramp surface S4.

In summary, in the current sensor of the embodiment of the present invention, since the anisotropic magnetoresistive unit is connected as a Wheatstone bridge to sense the magnetic field generated by the current in the wire, the current Sensing has high sensitivity and high accuracy. In addition, since the current sensor of the embodiment of the present invention uses the magnetic field generated by the current to reverse the magnitude of the current, and the anisotropic magnetoresistive unit does not directly contact the current, it can have a lower Power consumption.

Although the present invention has been disclosed as above with examples, it is not intended to limit the present invention. Any person with ordinary knowledge in the technical field can make some changes and modifications without departing from the spirit and scope of the present invention. The scope of protection of the present invention shall be subject to the scope defined in the appended patent application.

100, 100a, 100b, 100c, 100d ‧‧‧ current sensor 120‧‧‧ package 210‧‧‧ substrate 212‧‧‧ first end 214‧‧‧ second end 215‧‧‧ insulation layer 222‧‧ ‧The first anisotropic magnetoresistive unit 224‧‧‧The second anisotropic magnetoresistive unit 226‧‧‧The third anisotropic magnetoresistive unit 228‧‧‧The fourth anisotropic magnetoresistive unit 300‧‧‧ Directional magnetoresistance 310‧‧‧Short bar 312‧‧‧Sense direction 320‧‧‧Ferromagnetic film 400‧‧‧‧Arithmetic 410, 420‧‧‧Arithmetic arithmetic unit C‧‧‧ Lead D‧‧‧ Extension direction D1‧‧‧ First direction D2‧‧‧Second direction D3‧‧‧ Third direction H‧‧‧External magnetic field HC‧‧‧Magnetic field components HE1, HE2, HE3‧‧‧External magnetic field components I, i, I1, I2‧‧‧ Current M, M10, M1256, M15, M15', M20, M26, M26', M30, M3478, M37, M37', M40, M48, M48'‧‧‧Magnetization direction M1, M1a‧‧ ‧First magnetization direction setting element M2, M2a‧‧‧‧Second magnetization direction setting element P1, P1', P2, P2', P3, P3', P4, P4', P5, P5', P6' Point R1‧‧‧The first anisotropic magneto resistance R2‧‧‧The second anisotropic magneto resistance R3‧‧‧The third anisotropy magneto resistance R4‧‧‧The fourth anisotropy magneto resistance R5‧‧‧ Five anisotropic magnetoresistance R6‧‧‧Sixth anisotropy magnetism R7‧‧‧Seventh anisotropy magnetoresistance R8‧‧‧Eighth anisotropy magnetoresistance ΔR‧‧‧Resistance value change S1‧‧‧ The first slope surface S2‧‧‧The second slope surface S3‧‧‧The third slope surface S4‧‧‧The fourth slope surface V ₁ ‧‧‧ The first voltage signal V ₂ ‧‧‧The second voltage signal V _off ‧‧ ‧Offset voltage signal V _out ‧‧‧Output voltage signal

FIG. 1 is a schematic top view of a current sensor according to an embodiment of the invention. 2 is a schematic cross-sectional view of the current sensor of FIG. 1 along line A-A. 3A and 3B are used to explain the operation principle of the anisotropic magnetoresistance in FIG. 1. 4A and 4B respectively illustrate the magnetization direction of the anisotropic magnetoresistance of the current sensor of FIG. 1 at the first time and the second time and the change in resistance value thereafter. FIG. 5 is an output voltage-current curve diagram of the Wheatstone bridge of FIGS. 4A and 4B. FIG. 6 illustrates that the Wheatstone bridge of FIGS. 4A and 4B is coupled to an arithmetic unit. FIG. 7 illustrates the change in resistance of the current sensor of FIG. 1 when the magnetization direction of the anisotropic magnetoresistance at the first time and the external magnetic field components in three different directions are subsequently received. FIG. 8 and FIG. 9 respectively illustrate the resistance value change of the current sensor of FIG. 1 when the magnetization direction of the anisotropic magnetoresistance at the second time and the external magnetic field components in three different directions are subsequently received. 10 is a schematic top view of a current sensor according to another embodiment of the invention. 11 is a schematic top view of a current sensor according to another embodiment of the invention. FIG. 12A is a schematic top view of a current sensor according to still another embodiment of the invention. 12B is a schematic cross-sectional view of the current sensor of FIG. 12A along line A1-A1. FIG. 13A is a schematic top view of a current sensor according to another embodiment of the invention. 13B is a schematic cross-sectional view of the current sensor of FIG. 13A along line A2-A2.

100‧‧‧current sensor

210‧‧‧ substrate

212‧‧‧The first end

214‧‧‧second end

222‧‧‧The first anisotropic magnetoresistive unit

224‧‧‧The second anisotropic magnetoresistive unit

226‧‧‧The third anisotropic magnetoresistive unit

228‧‧‧The fourth anisotropic magnetoresistive unit

312‧‧‧Sense direction

C‧‧‧Wire

D1‧‧‧First direction

D2‧‧‧Second direction

D3‧‧‧third direction

I‧‧‧Current

M1‧‧‧First magnetization direction setting element

M2‧‧‧Second magnetization direction setting element

R1‧‧‧The first anisotropic magnetoresistance

R2‧‧‧Second anisotropic magnetoresistance

R3‧‧‧The third anisotropic magnetoresistance

R4‧‧‧ Fourth anisotropic magnetoresistance

R5‧‧‧The fifth anisotropic magnetoresistance

R6‧‧‧Sixth anisotropic magnetoresistance

R7‧‧‧The seventh anisotropic magnetoresistance

R8‧‧‧Eighth anisotropic magnetoresistance

S1‧‧‧The first slope

S2‧‧‧Second slope surface

S3‧‧‧The third slope

S4‧‧‧The fourth slope

Claims (14)

A current sensor, including: A substrate A first slope surface and a second slope surface, which are arranged on the substrate and arranged in a first direction; At least one wire extending along a second direction and disposed on one side of the substrate; A first anisotropic magnetoresistive unit arranged on the first slope surface; A second anisotropic magnetoresistive unit disposed on the second slope surface; A first magnetization direction setting element for setting the magnetization direction of the first anisotropic magnetoresistive unit; and A second magnetization direction setting element for setting the magnetization direction of the second anisotropic magnetoresistive unit, When a current flows through the wire, a third-direction magnetic field component generated by the current at the first ramp surface is opposite to the third-direction magnetic field component generated by the current at the second ramp surface, The first direction, the second direction, and the third direction are different from each other, and the sensing directions of the first anisotropic magnetoresistive unit and the second anisotropic magnetoresistive unit are relative to the first direction and the third direction The three directions are inclined and different from the second direction, the first anisotropic magnetoresistive unit and the second anisotropic magnetoresistive unit are electrically connected to output a voltage signal, the voltage signal corresponding to the current in the The third-direction upward magnetic field component generated at the first slope surface and the second slope surface. The current sensor as described in item 1 of the patent application scope further includes: A third slope surface and a fourth slope surface are provided on the substrate, wherein the third slope surface is opposite to the first slope surface, the fourth slope surface is opposite to the second slope surface, and the first slope The surface, the third slope surface, the fourth slope surface and the second slope surface are sequentially arranged in the first direction; A third anisotropic magnetoresistive unit disposed on the third slope surface, the first magnetization direction setting element is also used to set the magnetization direction of the third anisotropic magnetoresistive unit; and A fourth anisotropic magnetoresistive unit is disposed on the fourth slope surface, and the second magnetization direction setting element is also used to set the magnetization direction of the fourth anisotropic magnetoresistive unit, wherein when the current flows through the When conducting a wire, due to the magnetic field induced by the current, the change in resistance value generated by the first anisotropic magnetoresistive unit is opposite to the change in resistance value generated by the third anisotropic magnetoresistive unit, and the second The change in resistance value generated by the anisotropic magnetoresistive unit is opposite to the change in resistance value generated by the fourth anisotropic magnetoresistive unit, and the first, second, third, and fourth anisotropic magnetoresistive units are electrically It is connected to a Wheatstone bridge to output a voltage signal corresponding to the change in resistance value generated by the first, second, third and fourth anisotropic magnetoresistive units. The current sensor as described in item 2 of the patent application scope further includes an arithmetic unit electrically connected to an output end of the Wheatstone bridge, wherein the first magnetization direction setting element and the second magnetization direction The setting element sets the magnetization direction combination of the first, second, third and fourth anisotropic magnetoresistive units to a first combination, so that the Wheatstone bridge outputs a first voltage signal, and the The first magnetization direction setting element and the second magnetization direction setting element set the magnetization direction combinations of the first, second, third and fourth anisotropic magnetoresistive units to a second opposite to the first combination Combination, so that the Wheatstone bridge outputs a second voltage signal afterwards, the calculator is used to subtract the second voltage signal from the first voltage signal to output a magnetic field corresponding to the magnetic field generated by the current The size of the output voltage signal. The current sensor as described in item 3 of the patent application scope, wherein the arithmetic unit is used to add the first voltage signal and the second voltage signal to output an offset voltage signal. The current sensor as described in item 2 of the patent application scope, wherein the Wheatstone bridge corresponds to the voltage signal output by the external magnetic field component in the first direction being zero, corresponding to the second direction The voltage signal output by the external magnetic field component on is zero, and the voltage signal corresponding to the external magnetic field component in the third direction is zero. The current sensor as described in item 2 of the patent application scope, wherein the first anisotropic magnetoresistive unit includes a first anisotropic magnetoresistive and a first Two anisotropic magnetoresistances, the second anisotropic magnetoresistance unit includes a third anisotropic magnetoresistance and a fourth anisotropic magnetoresistance arranged in sequence along the reverse direction of the second direction The three anisotropic magneto-resistance units include a fifth anisotropic magneto-resistance and a sixth anisotropic magneto-resistance arranged in sequence along the opposite direction of the second direction, and the fourth anisotropic magneto-resistance unit includes A seventh anisotropic magnetoresistance and an eighth anisotropic magnetoresistance are sequentially arranged along the reverse direction of the second direction. The current sensor as described in item 6 of the patent application range, wherein at a first time, the first magnetization direction setting element magnetizes the first anisotropic magnetoresistance and the fifth anisotropic magnetoresistance Set to the opposite direction of the second direction, and set the magnetization directions of the second anisotropic magnetoresistance and the sixth anisotropic magnetoresistance to the second direction; at the first time, the second magnetization direction The setting element sets the magnetization directions of the third anisotropic magnetoresistance and the seventh anisotropic magnetoresistance to the opposite direction of the second direction, and sets the fourth anisotropic magnetoresistance and the eighth anisotropy The magnetization direction of the magnetoresistance is set to the second direction; at a second time, the first magnetization direction setting element sets the magnetization directions of the first anisotropic magnetoresistance and the fifth anisotropic magnetoresistance to the first Two directions, and the magnetization directions of the second anisotropic magnetoresistance and the sixth anisotropic magnetoresistance are set to be opposite to the second direction; at the second time, the second magnetization direction setting element sets The magnetization directions of the third anisotropic magnetoresistance and the seventh anisotropic magnetoresistance are set to the second direction, and the magnetization directions of the fourth anisotropic magnetoresistance and the eighth anisotropic magnetoresistance are set to The opposite direction of the second direction. The current sensor as described in item 1 of the patent application range, wherein the first magnetization direction setting element and the second magnetization direction setting element are conductive sheets, conductive coils, wires, conductors or permanent magnets. The current sensor according to item 1 of the patent application scope, wherein the first direction, the second direction, and the third direction are perpendicular to each other. The current sensor according to item 1 of the patent application scope, wherein the at least one wire is a wire, the first slope surface and the second slope surface are located on a first side of the substrate, and the wire is located on the substrate A second side, and the first side is opposite to the second side. The current sensor as recited in item 10 of the patent application range, wherein the first slope surface and the second slope surface are respectively located on one side of the opposite ends of the substrate, and the wire is located on the side of the center of the substrate . The current sensor according to item 1 of the patent application scope, wherein the at least one wire is two wires, which are respectively disposed beside a first end and a second end of the substrate, wherein the first end is opposite to the The second end, and the two wires partially overlap the first end and the second end, respectively. The current sensor according to item 1 of the patent application scope, wherein the at least one wire is two wires, which are respectively disposed beside a first end and a second end of the substrate, wherein the first end is opposite to the The second end, and the two wires do not overlap with the first end and the second end, respectively. The current sensor as described in item 1 of the patent application scope, wherein the first anisotropic magnetoresistive unit and the second anisotropic magnetoresistive unit are electrically connected to form a Wheatstone bridge, and the output corresponds to the first A voltage signal of a change in resistance value generated by an anisotropic magnetoresistive unit and a second anisotropic magnetoresistive unit.

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