Magnetoresistive element, preparation method thereof and electronic equipment

Abstract

The invention relates to the technical field of magnetic field measurement, and discloses a magnetoresistive element, a preparation method thereof and electronic equipment. The magnetic resistance element comprises a base body, magnetic resistance sub-elements and a plurality of magnetic flux adjusting blocks, the magnetic resistance sub-elements and the plurality of magnetic flux adjusting blocks are located above the base body, and the plurality of magnetic flux adjusting blocks comprise a first magnetic flux adjusting block, a second magnetic flux adjusting block, a third magnetic flux adjusting block and a fourth magnetic flux adjusting block which are separated from one another. The first area is used for forming a first area with a stable magnetic field, the magnetic field intensity of the first area is N times of that of an external magnetic field, and N is a positive integer smaller than 1; the magnetic resistance sub-element is located in the first area, has an in-plane magnetic sensitive direction and is used for sensing information of an external magnetic field in a preset magnetic field intensity range; the magnetic field measurement range of the magnetoresistive element is widened through the magnetic flux adjusting block, the magnetic field measurement range of the magnetoresistive element is controllable through parameter adjustment of the magnetic flux adjusting block, and the magnetoresistive element has the advantages of being simple in structure and easy to achieve.

Description

Technical Field

[0001] The present invention relates to the field of magnetic field measurement technology, and in particular to a magnetoresistive element, a preparation method thereof, and electronic equipment. Background Art

[0002] Magnetic field sensors can convert magnetic field changes into other physical changes, thereby realizing the function of magnetic field detection.

[0003] TMR magnetoresistive sensors based on the tunneling magnetoresistance effect have the advantages of high sensitivity, small size, low power consumption and easy integration. The magnetoresistive structure in the TMR magnetoresistive sensor can generally only sense magnetic fields within a certain range of magnetic field strength. When the magnetic field to be sensed exceeds the certain range of magnetic field strength, the magnetoresistive structure generally needs to be redesigned.

[0004] How to enable the magnetic field sensor to achieve wide-range magnetic field measurement without changing the magnetoresistive structure needs to be solved urgently. Summary of the invention

[0005] The purpose of the present invention is to provide a magnetoresistive element and an electronic device, which are used to solve the problem that the existing magnetic field sensor relies on the magnetoresistive structure to achieve wide-range magnetic field measurement.

[0006] A first aspect of the present invention provides a magnetoresistive element. The magnetoresistive element comprises: matrix; A plurality of magnetic flux regulating blocks, located above the substrate, including a first magnetic flux regulating block, a second magnetic flux regulating block, a third magnetic flux regulating block and a fourth magnetic flux regulating block separated from each other, used to form a first region with a stable magnetic field and to make the magnetic field strength of the magnetic field in the first region decay to N times of the external magnetic field, wherein N is a positive integer less than 1; The magnetoresistive element is located above the substrate and within the first region, has an in-plane magnetic sensitivity direction, and is used to sense information of the external magnetic field within a preset magnetic field strength range.

[0007] According to some embodiments of the present invention, the first region has a first opening perpendicular to the magnetic sensitive direction; and the external magnetic field enters the first region through the first opening.

[0008] According to some embodiments of the present invention, the first magnetic flux regulating block and the second magnetic flux regulating block have a first square structure, are respectively located on two opposite sides of the magnetic resistance sub-element, and their length directions are perpendicular to the magnetic sensitive direction; The third magnetic flux regulating block and the fourth magnetic flux regulating block have a second square structure and are respectively located on the other two opposite sides of the magnetic resistance sub-element, and their length directions are parallel to the magnetic sensitive direction.

[0009] According to some embodiments of the present invention, the maximum distance from the first magnetic flux regulating block to the second magnetic flux regulating block along the direction parallel to the magnetic sensitive direction is less than the length of the third magnetic flux regulating block; The distance between the third magnetic flux regulating block and the fourth magnetic flux regulating block is greater than the length of the first magnetic flux regulating block.

[0010] According to some embodiments of the present invention, the length of the third magnetic flux regulating block is 2 cm to 4 cm.

[0011] According to some embodiments of the present invention, a distance between the third magnetic flux regulating block and the fourth magnetic flux regulating block is 1.2 cm to 2 cm.

[0012] According to some embodiments of the present invention, the length of the first magnetic flux regulating block is 0.8-1.2 cm.

[0013] According to some embodiments of the present invention, the minimum thickness of the first magnetic flux regulating block, the second magnetic flux regulating block, the third magnetic flux regulating block, and the fourth magnetic flux regulating block is greater than the thickness of the magnetoresistive element.

[0014] According to some embodiments of the present invention, the plurality of magnetic flux regulating blocks are made of soft magnetic material.

[0015] According to some embodiments of the present invention, the plurality of flux regulating blocks are ferromagnetic alloys, and the ferromagnetic alloys contain one or more elements of Ni, Fe, Co, Si, B, Zr or Al.

[0016] According to some embodiments of the present invention, the magnetoresistive element is AMR, GMR or TMR.

[0017] According to some embodiments of the present invention, the magnetoresistive element has a Wheatstone bridge structure.

[0018] A second aspect of the present invention provides a method for preparing the above-mentioned magnetoresistive element, the method comprising the following steps: (1) placing a first magnetic flux regulating block, a second magnetic flux regulating block, a third magnetic flux regulating block, and a fourth magnetic flux regulating block separated from each other on a substrate; (2) placing a magnetoresistive wafer in the first region of the substrate to obtain the magnetoresistive element; The first area is located in an area surrounded by the first magnetic flux regulating block, the second magnetic flux regulating block, the third magnetic flux regulating block and the fourth magnetic flux regulating block.

[0019] A third aspect of the present invention provides an electronic device; the electronic device comprises a magnetoresistive element; the magnetoresistive element is the magnetoresistive element described above or a magnetoresistive element manufactured by the method described above.

[0020] Therefore, compared with the prior art, the present invention has the following beneficial effects: The magnetoresistive element provided by the present invention comprises a substrate, a magnetoresistive element located above the substrate, and a plurality of flux adjustment blocks; the plurality of flux adjustment blocks comprise a first flux adjustment block, a second flux adjustment block, a third flux adjustment block, and a fourth flux adjustment block separated from each other, which are used to form a first region and make the magnetic field strength of the first region decay to N times of the external magnetic field, wherein N is a positive integer less than 1; the magnetoresistive element is located in the first region, has an in-plane magnetic sensitive direction, and is used to sense information of the external magnetic field within a preset magnetic field strength range; the present invention broadens the magnetic field measurement range of the magnetoresistive element through the flux adjustment blocks, and realizes controllable magnetic field measurement range of the magnetoresistive element through parameter adjustment of the flux adjustment blocks, and also has the beneficial effects of simple structure and easy implementation. BRIEF DESCRIPTION OF THE DRAWINGS

[0021] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on the structures shown in these drawings without paying creative work.

[0022] Figure 1 A schematic structural diagram of a magnetoresistive element according to an embodiment of the present invention; Figure 2 A schematic diagram of a Wheatstone bridge structure of a magnetoresistive element according to an embodiment of the present invention; Figure 3 A simulation diagram of the magnetic field strength around a magnetoresistive element according to an embodiment of the present invention; Figure 4 is a curve diagram showing the change of the magnetic field strength of the magnetoresistive element with the length of the third magnetoresistive adjustment block in one embodiment of the present invention; Figure 5 is a curve diagram showing the change in magnetic field strength of the magnetoresistive element as the distance between the third magnetoresistive adjustment block and the fourth magnetoresistive adjustment block changes in one embodiment of the present invention; Figure 6 is a curve diagram showing the change of the magnetic field strength of the magnetoresistive element with the length of the first magnetoresistive adjustment block in one embodiment of the present invention; Figure 7 A curve showing a change in voltage output of a magnetoresistive element as a function of magnetic field according to another embodiment of the present invention; Figure 8 A curve showing a change in voltage output of a magnetoresistive element as a function of magnetic field according to another embodiment of the present invention; Fig. 9 FIG. 4 is a schematic flow chart of a method for preparing a magnetoresistive element according to an embodiment of the present invention.

[0023] The realization of the purpose, functional features and advantages of the present invention will be further explained in conjunction with embodiments and with reference to the accompanying drawings. DETAILED DESCRIPTION

[0024] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0025] It should be noted that if the embodiments of the present invention involve directional indications (such as up, down, left, right, front, back, etc.), the directional indications are only used to explain the relative position relationship, movement status, etc. between the components in a certain specific posture. If the specific posture changes, the directional indication will also change accordingly.

[0026] In addition, if there are descriptions involving "first", "second", etc. in the embodiments of the present invention, the descriptions of "first", "second", etc. are only used for descriptive purposes and cannot be understood as indicating or implying their relative importance or implicitly indicating the number of technical features indicated. Therefore, the features limited to "first" and "second" may explicitly or implicitly include at least one of the features. In addition, if "and / or" or "and / or" appears in the full text, its meaning includes three parallel solutions. Taking "A and / or B" as an example, it includes solution A, solution B, or solutions that satisfy both A and B. In addition, the technical solutions between the various embodiments can be combined with each other, but it must be based on the ability of ordinary technicians in this field to implement. When the combination of technical solutions is contradictory or cannot be implemented, it should be deemed that such combination of technical solutions does not exist and is not within the scope of protection required by the present invention.

[0027] Magnetic field sensors can convert magnetic field changes into other physical changes, thereby realizing the function of magnetic field detection.

[0028] TMR magnetoresistive sensors based on the tunneling magnetoresistance effect have the advantages of high sensitivity, small size, low power consumption and easy integration. The magnetoresistive structure in the TMR magnetoresistive sensor can generally only sense magnetic fields within a certain range of magnetic field strength. When the magnetic field to be sensed exceeds the certain range of magnetic field strength, the magnetoresistive structure generally needs to be redesigned.

[0029] How to enable the magnetic field sensor to achieve wide-range magnetic field measurement without changing the magnetoresistive structure needs to be solved urgently.

[0030] An embodiment of the present invention provides a magnetoresistive element, which is used to solve the problem that the existing magnetoresistive element relies on the magnetoresistive structure to achieve wide-range magnetic field measurement.

[0031] like Figure 1 As shown, the magnetoresistive element of one embodiment of the present invention comprises a substrate 40, a magnetoresistive element 10 and four magnetic flux regulating blocks 21, 22, 31, 32 located above the substrate 40. The four magnetic flux regulating blocks include a first magnetic flux regulating block 21, a second magnetic flux regulating block 22, a third magnetic flux regulating block 31 and a fourth magnetic flux regulating block 32 separated from each other, which are used to form a first region 41 with a stable magnetic field and make the magnetic field strength of the magnetic field in the first region 41 decay to N times of the external magnetic field, where N is a positive integer less than 1; the magnetoresistive element 10 is located in the middle of the first region 41, has an in-plane magnetic sensitive direction, and is used to sense the information of the external magnetic field within a preset magnetic field strength range.

[0032] It should be understood that the first area is located in the area enclosed by the first flux regulating block, the second flux regulating block, the third flux regulating block and the fourth flux regulating block, and the magnetic resistance element should be located in the first area, not limited to the middle position of the first area.

[0033] The magnetic field direction of the external magnetic field sensed by the magnetoresistive element should be parallel to the magnetic sensitive direction of the magnetoresistive element, and the magnetic sensitive direction is parallel to the substrate plane. The number of the flux regulating blocks is not limited to 4, and can be 4 or more.

[0034] The first magnetic flux regulating block 21, the second magnetic flux regulating block 22, the third magnetic flux regulating block 31 and the fourth magnetic flux regulating block 32 of the embodiment of the present invention surround the magnetic flux sub-element 10 through four sides so that the magnetic field strength in the first area 41 surrounded by them is reduced to the sensible range of the magnetoresistive sub-element 10, thereby widening the sensible range of the magnetoresistive element.

[0035] The first region 41 of the embodiment of the present invention has a uniform and stable magnetic field, which enables the magnetoresistive element 10 to output the current situation of the external magnetic field based on the magnetic field information of the first region 41 .

[0036] like Figure 2 As shown, the magnetoresistive element 10 of the embodiment of the present invention comprises a first magnetoresistive arm R1, a second magnetoresistive arm R2, a third magnetoresistive arm R3 and a fourth magnetoresistive arm R4 coupled in sequence. The magnetoresistive element is a TMR element with a Wheatstone bridge structure.

[0037] It should be noted that the magnetoresistive element is not limited to TMR, but may also be AMR, GMR or other devices with magnetoresistive effect, which is not specifically limited here.

[0038] The magnetoresistive element 10 of the embodiment of the present invention has a small magnetic field detection range. If it is directly used for large magnetic field detection, it will not be directly implemented because it exceeds the detectable range. Under the synergistic effect of the four flux adjustment blocks, the magnetic field around the magnetoresistive element 10 is reduced from a large magnetic field to a small magnetic field detectable by the magnetoresistive element, thereby realizing wide-range magnetic field measurement.

[0039] The first region 41 of the embodiment of the present invention is a non-enclosed region, which has four openings, which are perpendicular to the magnetic sensitive direction, and the external magnetic field can enter and exit the first region through the openings. The four openings are respectively located between the first magnetic flux regulating block and the third magnetic flux regulating block, between the first magnetic flux regulating block and the fourth magnetic flux regulating block, between the second magnetic flux regulating block and the third magnetic flux regulating block, and between the second magnetic flux regulating block and the fourth magnetic flux regulating block.

[0040] It should be noted that the first region 41 may have a plurality of openings perpendicular to the magnetic sensitive direction, and the number of the openings is not specifically limited here. The first region 41 may also have an opening parallel to the magnetic sensitive direction, and the number of the openings parallel to the magnetic sensitive direction is not specifically limited here.

[0041] The first magnetic flux regulating block 21 and the second magnetic flux regulating block 22 of the embodiment of the present invention both have a first square structure, and are respectively located on two opposite sides of the magnetic resistance element 10; and their length directions are perpendicular to the magnetic sensitivity direction.

[0042] It should be understood that the third magnetic flux regulating block and the fourth magnetic flux regulating block are preferably arranged in parallel. The first magnetic flux regulating block and the second magnetic flux regulating block may also be arranged in a non-parallel manner.

[0043] The first magnetic flux regulating block 21 is located on the left side of the magnetoresistive element, and there is a certain gap between the first magnetic flux regulating block 21 and the magnetoresistive element 10; the second magnetic flux regulating block 22 is located on the right side of the magnetoresistive element 10, and there is also a certain gap between the second magnetic flux regulating block 22 and the magnetoresistive element 10, and the size of the gap is not limited here.

[0044] The third magnetic flux regulating block 31 and the fourth magnetic flux regulating block 32 of the embodiment of the present invention both have a second square structure, which are respectively located on the other two opposite sides of the magnetic resistance element 10, and the length direction thereof is parallel to the magnetic sensitivity direction.

[0045] It should be understood that the third magnetic flux regulating block and the fourth magnetic flux regulating block are preferably arranged in parallel.

[0046] The third magnetic flux regulating block 31 is located on the upper side of the magnetoresistive element 10, and there is a certain gap between the third magnetic flux regulating block 31 and the magnetoresistive element 10, and the gap exceeds the minimum distance from the magnetoresistive element 10 to the upper side of the first magnetic flux regulating block 21; the fourth magnetic flux regulating block is located on the lower side of the magnetoresistive element, and there is a certain gap between the fourth magnetic flux regulating block and the magnetoresistive element, and the gap exceeds the minimum distance from the magnetoresistive element to the lower side of the first magnetic flux regulating block.

[0047] The maximum distance from the first magnetic flux regulating block 21 to the second magnetic flux regulating block 22 along the direction parallel to the magnetic sensitivity direction in the embodiment of the present invention is smaller than the length d1 of the third magnetic flux regulating block; the distance d2 between the third magnetic flux regulating block 31 and the fourth magnetic flux regulating block 32 is greater than the length d3 of the first magnetic flux regulating block.

[0048] The thickness of the first magnetic flux regulating block 21 , the second magnetic flux regulating block 22 , the third magnetic flux regulating block 31 , and the fourth magnetic flux regulating block 32 in the embodiment of the present invention are all twice the thickness of the magnetoresistive element.

[0049] It should be noted that the minimum thickness of the first magnetic flux regulating block, the second magnetic flux regulating block, the third magnetic flux regulating block and the fourth magnetic flux regulating block should be greater than the thickness of the magnetic resistance sub-element to prevent the external magnetic field from bypassing each magnetic flux regulating block and affecting the surrounding magnetic field of the magnetic resistance sub-element. The minimum thickness is not specifically limited here.

[0050] The length d1 of the third magnetic flux regulating block in the embodiment of the present invention is 2.5 cm.

[0051] It should be noted that the length of the third magnetic flux regulating block and the fourth magnetic flux regulating block is preferably 2 cm to 4 cm.

[0052] The distance d2 between the third magnetic flux regulating block and the fourth magnetic flux regulating block in the embodiment of the present invention is 1.4 cm.

[0053] It should be noted that the distance between the third magnetic flux regulating block and the fourth magnetic flux regulating block is preferably 1.2-2 cm.

[0054] The length of the first magnetic flux regulating block in the embodiment of the present invention is 1 cm.

[0055] It should be noted that the length of the first magnetic flux regulating block is preferably 0.8 cm to 1.2 cm.

[0056] The material of the magnetic flux regulating block in the embodiment of the present invention is NiFe alloy.

[0057] It should be noted that the magnetic flux regulating block can be a soft magnetic material. Preferably, the magnetic flux regulating block is a ferromagnetic alloy containing one or more elements of Ni, Fe, Co, Si, B, Zr or Al. It is not specifically limited here.

[0058] The magnetic field strength around each flux regulating block of the embodiment of the present invention is simulated, and the results are as follows: Figure 3 As shown. Figure 3 , a uniform and stable magnetic field is formed around the first area surrounded by the first magnetic flux regulating block, the second magnetic flux regulating block, the third magnetic flux regulating block and the fourth magnetic flux regulating block, and the magnetic field is much lower than the magnetic field strength of the magnetic field around the magnetic resistance element. This indicates that each magnetic flux regulating block of the present invention can attenuate the magnetic field around the magnetic resistance element.

[0059] An external magnetic field of 4000 Oe is applied to the magnetoresistive element of the embodiment of the present invention, and the length d1 of the third magnetic flux adjustment block in the magnetoresistive element of the embodiment of the present invention is adjusted to 2-4 cm, and the magnetic field conditions at various positions in the first region are observed. The direction parallel to the magnetic sensitive direction is the x-axis, the direction perpendicular to the magnetic sensitive axis is the y-axis, and the center position of the first region is the origin. According to the observation results, the magnetic field at each point in the first region is related to the length and y-axis position of the third magnetic flux adjustment block, but has nothing to do with its x-axis position. Figure 4 As shown, the magnetic field at each position in the first region decreases as the length of the third flux regulating block increases; when the positions of the flux regulating blocks are fixed, the magnetic field strength at each position (x, y) in the first region does not change with the change of the y value when |y|≤y1, but decreases with the increase of the y value when |y|>y1, where y1>0, and the y1 value increases with the increase of the length d1 of the third flux regulating block. Based on Figure 4 When the length of the third magnetic flux regulating block is 2-4 cm, the magnetic field strength of the magnetoresistive element is lower than 1000 Oe when |y|≤y1, which is much lower than the magnetic field strength of the external magnetic field 4000 Oe, indicating that the synergistic effect of each magnetic flux regulating block can form a stable and low magnetic field first region. It also shows that adjusting the length of the third magnetic flux regulating block can adjust the attenuation degree of the magnetic field around the magnetoresistive element by the magnetic flux regulating block.

[0060] An external magnetic field of 4000 Oe is applied to the magnetoresistive element of the embodiment of the present invention, and the spacing between the third magnetic flux regulating block and the fourth magnetic flux regulating block in the magnetoresistive element of the embodiment of the present invention is adjusted to 1.2 cm to 2 cm, and the magnetic field conditions at various positions in the first region are observed. According to the observation results, the magnetic field at each point in the first region is related to the spacing and the y-axis position, but not to its x-axis position. Figure 5 As shown, the magnetic field at each position in the first region decreases as the spacing d2 increases; when the positions of the flux regulating blocks are fixed, the magnetic field strength at each position (x, y) in the first region does not change with the change of the y value when |y|≤y2, but decreases with the increase of the y value when |y|>y2, where y2>0, and the y2 value decreases with the increase of the spacing d2. Figure 5When the distance between the third magnetic flux regulating block and the fourth magnetic flux regulating block is 1.2~2cm, the magnetic field strength of the magnetoresistive element is lower than 1500Oe when |y|≤y2, which is much lower than the magnetic field strength of the external magnetic field 4000Oe, indicating that each magnetic flux regulating block can form a stable and low magnetic field first region. It also shows that adjusting the distance between the third magnetic flux regulating block and the fourth magnetic flux regulating block can adjust the attenuation degree of the magnetic field around the magnetoresistive element by the magnetic flux regulating block.

[0061] An external magnetic field of 4000 Oe is applied to the magnetoresistive element of the embodiment of the present invention, and the length of the first magnetic flux regulating block in the magnetoresistive element of the embodiment of the present invention is adjusted to 0.8-1.2 cm, and the magnetic field conditions at various positions in the first region are observed. According to the observation results, the magnetic field at each point in the first region is related to the length d3 and the y-axis position of the first magnetic flux regulating block, but has nothing to do with its x-axis position. Figure 6 As shown, the magnetic field at each position in the first region increases with the increase of the length d3 of the first flux regulating block; when the positions of the flux regulating blocks are fixed, the magnetic field strength at each position (x, y) in the first region does not change with the change of the y value when |y|≤y3, but decreases with the increase of the y value when |y|>y3, where y3>0, and the y3 value decreases with the increase of the length d3 of the first flux regulating block. Figure 6 When the length of the first magnetic flux regulating block is 0.8~1.2cm, the magnetic field strength of the magnetoresistive element is lower than 720 Oe when |y|≤y3, which is much lower than the magnetic field strength of the external magnetic field 4000Oe, indicating that the synergistic effect of each magnetic flux regulating block can form a stable and low magnetic field first region. It also shows that adjusting the length of the first magnetic flux regulating block can adjust the attenuation degree of the magnetic field around the magnetic resistance sub-element by the magnetic flux regulating block.

[0062] Therefore, the embodiment of the present invention reduces the magnetic field around the magnetic field element to a smaller uniform magnetic field through the flux adjustment block, and also achieves controllable attenuation degree of the magnetic field around the magnetic resistance sub-element by the flux adjustment block through the parameters of the flux adjustment block.

[0063] In another embodiment of the present invention, the hysteresis loop of the magnetoresistive element under the external magnetic field is as follows: Figure 7 As shown. Figure 7 The output voltage of the magnetoresistive element increases linearly with the increase of magnetic field strength at ±200 Oe, indicating that the magnetoresistive element of the embodiment of the present invention can be used for measuring external magnetic fields of ±200 Oe.

[0064] The hysteresis loop of the magnetoresistive element having the magnetoresistive element under an external magnetic field is as follows: Figure 8 As shown. Figure 8The output voltage of the magnetoresistive element increases linearly with the increase of magnetic field strength at ±1000 Oe, indicating that the magnetoresistive element of the embodiment of the present invention can be used to measure the external magnetic field of ±1000 Oe.

[0065] Therefore, the magnetoresistive element of the embodiment of the present invention is used for magnetic field measurement, which greatly broadens the magnetic field measurement range of the magnetoresistive element and also has the beneficial effects of simple structure and easy implementation.

[0066] In summary, the magnetoresistive element of the embodiment of the present invention can expand the magnetic field measurement range without relying on the structural change of the magnetoresistive element. When applied to large magnetic field measurement, the attenuation degree of the external magnetic field of the magnetic flux adjustment block can be adjusted by adjusting the parameters of each magnetic flux adjustment block, such as the length of the first adjustment block, the distance between the third adjustment block and the fourth adjustment block, and the length of the third adjustment block, so that the attenuation degree of the external magnetic field of the magnetoresistive element can be controlled, and the magnetic field measurement range of the magnetoresistive element can be controlled.

[0067] It should be noted that the magnetoresistive element of the embodiment of the present invention can fix the magnetoresistive element in the application, and the magnetoresistive element can be placed in different magnetic flux adjustment components to obtain magnetoresistive elements with different magnetic field measurement ranges, so as to adjust the inductive magnetic field range of the magnetoresistive element through different attenuation degrees of the magnetic flux adjustment component. For example, if the magnetic field measurement range of the magnetoresistive element is ±200Oe, and the attenuation degree of the magnetic flux adjustment component is one-half, the magnetic field measurement range of the magnetoresistive element is extended to ±400Oe; if the attenuation degree of the magnetic flux adjustment component is one-fifth, the magnetic field measurement range of the magnetoresistive element is extended to ±1000Oe. Therefore, it is easier to realize a wide range of the magnetoresistive element of the embodiment of the present invention.

[0068] The present invention also provides a method for preparing the aforementioned magnetoresistive element. The method comprises the following steps: S100: placing a first magnetic flux regulating block, a second magnetic flux regulating block, a third magnetic flux regulating block and a fourth magnetic flux regulating block separated from each other on a substrate; Specifically, a first magnetic flux regulating block, a second magnetic flux regulating block, a third magnetic flux regulating block and a fourth magnetic flux regulating block made of NiFe alloy are placed on the substrate. The first magnetic flux regulating block, the second magnetic flux regulating block, the third magnetic flux regulating block and the fourth magnetic flux regulating block are all square structures, the first magnetic flux regulating block has the same structure as the second magnetic flux regulating block and is placed in parallel, the third magnetic flux regulating block has the same structure as the fourth magnetic flux regulating block and is placed in parallel, and its length direction is perpendicular to the length direction of the first magnetic flux regulating block.

[0069] The material of each magnetic flux regulating block is not limited to NiFe alloy, and may also be other soft magnetic materials, which is not specifically limited here.

[0070] The number of the flux regulating blocks is not limited to 4, and may also include a fifth flux regulating block, which is not specifically limited here.

[0071] S200: Placing a magnetoresistive wafer in a first region of a substrate to obtain a magnetoresistive element; wherein the first region is located in a region surrounded by a first magnetic flux regulating block, a second magnetic flux regulating block, a third magnetic flux regulating block, and a fourth magnetic flux regulating block.

[0072] Specifically, a magnetoresistive wafer with four magnetoresistive bridge arms is fixed in the middle of the first area, and then each pad in the magnetoresistive wafer is electrically coupled to the pins on the substrate through an electrical conductor to form a Wheatstone full-bridge structure, and a magnetoresistive element is obtained by packaging.

[0073] The pins on the substrate at least include a ground pin, a power pin, a positive differential pin, and a negative differential pin.

[0074] When the magnetoresistive wafer is fixed, the magnetically sensitive direction of the magnetoresistive wafer is perpendicular to the length direction of the first magnetic flux regulating block and parallel to the length direction of the third magnetic flux regulating block.

[0075] It should be noted that the number of magnetoresistive bridge arms in the magnetoresistive wafer is not limited to 4. When the number of magnetoresistive bridge arms is 2, the magnetoresistive wafer can form a Wheatstone half-bridge structure by electrical coupling, which is not specifically limited here.

[0076] The fixed position of the magnetoresistive wafer on the substrate is preferably the middle position of the first region, and may also be other positions near it, which is not specifically limited here.

[0077] The method for preparing the magnetoresistive element in the embodiment of the present invention may also include the following steps: S300: fixing the magnetoresistive wafer to the substrate; Specifically, a magnetoresistive wafer is fixed on a substrate; the magnetoresistive wafer includes four magnetoresistive bridge arms and eight pads electrically coupled to two ends of the four magnetoresistive bridge arms; S400: placing a first magnetic flux regulating block, a second magnetic flux regulating block, a third magnetic flux regulating block and a fourth magnetic flux regulating block around the magnetic resistance wafer on the substrate to obtain a magnetic resistance element; Specifically, a first magnetic flux regulating block, a second magnetic flux regulating block, a third magnetic flux regulating block and a fourth magnetic flux regulating block separated from each other and made of NiFe alloy are placed around a magnetoresistive wafer; each pad in the magnetoresistive wafer is electrically coupled to the pins on the substrate through an electrical conductor to form a Wheatstone bridge structure, thereby obtaining a magnetoresistive element.

[0078] A third embodiment of the present invention provides an electronic device, which includes the aforementioned magnetoresistive element.

[0079] The electronic device in the embodiment of the present invention may be a magnetic field sensor, a current sensor, a position sensor, a switch sensor, an angle sensor or other devices.

[0080] The above description is only an exemplary embodiment of the present invention, and does not limit the patent scope of the present invention. All equivalent structural changes made by using the contents of the present invention specification and drawings under the technical concept of the present invention, or directly / indirectly applied in other related technical fields are included in the patent protection scope of the present invention.

Claims

1. A magnetoresistive element, characterized in that: include: matrix; A plurality of magnetic flux regulating blocks, located above the substrate, including a first magnetic flux regulating block, a second magnetic flux regulating block, a third magnetic flux regulating block and a fourth magnetic flux regulating block separated from each other, used to form a first region with a stable magnetic field, and the magnetic field strength of the first region is N times that of the external magnetic field, wherein N is a positive integer less than 1; The magnetoresistive element is located above the substrate and within the first region, has an in-plane magnetic sensitivity direction, and is used to sense information of the external magnetic field within a preset magnetic field strength range.

2. The magnetoresistive element according to claim 1, characterized in that The first region has a first opening perpendicular to the magnetic sensitive direction; The external magnetic field enters the first region through the first opening.

3. The magnetoresistive element according to claim 1 or 2, characterized in that: The first magnetic flux regulating block and the second magnetic flux regulating block have a first square structure, are respectively located on two opposite sides of the magnetic resistance sub-element, and their length directions are perpendicular to the magnetic sensitive direction; The third magnetic flux regulating block and the fourth magnetic flux regulating block have a second square structure and are respectively located on the other two opposite sides of the magnetic resistance sub-element, and their length directions are parallel to the magnetic sensitive direction.

4. The magnetoresistive element according to claim 3, characterized in that The maximum distance from the first magnetic flux regulating block to the second magnetic flux regulating block along the direction parallel to the magnetic sensitive direction is smaller than the length of the third magnetic flux regulating block.

5. The magnetoresistive element according to claim 3, characterized in that The distance between the third magnetic flux regulating block and the fourth magnetic flux regulating block is greater than the length of the first magnetic flux regulating block.

6. The magnetoresistive element according to claim 3, characterized in that The length of the third magnetic flux regulating block is 2 cm to 4 cm; The distance between the third magnetic flux regulating block and the fourth magnetic flux regulating block is 1.2 cm to 2 cm; The length of the first magnetic flux regulating block is 0.8-1.2 cm.

7. The magnetoresistive element according to claim 1, characterized in that The minimum thickness of the first magnetic flux regulating block, the second magnetic flux regulating block, the third magnetic flux regulating block and the fourth magnetic flux regulating block is greater than the thickness of the magnetic resistance sub-element.

8. The magnetoresistive element according to claim 1, characterized in that The plurality of magnetic flux regulating blocks are made of soft magnetic material; Preferably, the plurality of flux regulating blocks are ferromagnetic alloys, and the ferromagnetic alloys contain one or more elements of Ni, Fe, Co, Si, B, Zr or Al.

9. The method for preparing a magnetoresistive element according to any one of claims 1 to 8, characterized in that: The following steps are involved: placing a first magnetic flux regulating block, a second magnetic flux regulating block, a third magnetic flux regulating block, and a fourth magnetic flux regulating block separated from each other on a substrate; Placing a magnetoresistive wafer in the first region of the substrate to obtain the magnetoresistive element; The first area is located in an area surrounded by the first magnetic flux regulating block, the second magnetic flux regulating block, the third magnetic flux regulating block and the fourth magnetic flux regulating block.

10. An electronic device, characterized in that: including a magnetoresistive element; The magnetoresistive element is the magnetoresistive element according to any one of claims 1 to 8, or the magnetoresistive element manufactured by the method according to claim 9.

Images