Magnetic field sensor and multi-axis magnetic field sensor

Abstract

The present application relates to the technical field of magnetic field measurement. Provided are a magnetic field sensor and a multi-axis magnetic field sensor. The magnetic field sensor comprises: a magnetic flux conversion module, a magnetic sensing module and a differential detection module, wherein the magnetic flux conversion module comprises a magnetic field input region, a magnetic field output region, a magnetic flux direction conversion region and a magnetic flux path connection region; the magnetic flux conversion module aggregates and amplifies a magnetic field to be measured that is in a magnetic field sensing direction, and converts same into a magnetic field component in a spatial solid angle direction that forms an included angle of 0-90 degrees with the direction of said magnetic field; and the magnetic sensing module senses a magnetic field at an air gap of the magnetic flux conversion module, generates a differential voltage signal and forms, by means of the differential detection module, an output electrical signal to be measured, such that the magnetic field to be measured can be converted at the air gap into a magnetic field component in an opposite direction. Thus, differential detection of a push-pull bridge structure is implemented by using a magnetic sensing module in the same sensitivity direction, integrated manufacturing can be used, the process is simple, and good sensitivity consistency is achieved, thereby facilitating production.

Description

Magnetic field sensor and multi-axis magnetic field sensor Technical Field

[0001] The present application relates to the field of magnetic field measurement technology, and in particular to a magnetic field sensor and a multi-axis magnetic field sensor. Background Art

[0002] Magnetic sensors are widely used in modern industry and electronics, measuring physical parameters such as current, position, and direction by sensing changes in magnetic field strength. In the prior art, many different types of sensors are used to measure magnetic fields and other parameters, such as those using giant magneto-impedance (GMI), fluxgate, Hall element, and anomalous Hall element (AHE), as well as magnetoresistive (MR) sensors such as anisotropic magnetoresistance (AMR), giant magnetoresistance (GMR), tunnel magnetoresistance (TMR), perpendicular tunnel magnetoresistance (PTMR), and colossal magnetoresistance (CMR). A common measurement method for magnetic sensors is to use a bridge structure for differential detection to generate a voltage output, using differential full-bridge, differential half-bridge, push-pull full-bridge, and push-pull half-bridge configurations to sense the magnetic field to be measured.

[0003] At present, in order to form a differential detection structure, the magnetic induction module used in existing sensors usually has two opposite sensitivity directions. Its implementation methods include: (1) using separate push arm and wrist arm slices, which requires the two slices to be precisely positioned in the same plane, which is prone to angle deviation and zero point offset, affecting sensitivity consistency and measurement accuracy. (2) using a ferromagnetic reference layer design with a multi-layer thin film structure. Since at least two multi-layer thin film structures need to be introduced when depositing the multi-layer thin film, the complexity of the micromachining process is increased. (3) using a laser program-controlled heating magnetic field annealing method, which requires specific equipment, complex process and high cost.

[0004] Summary of the Invention

[0005] In view of this, the purpose of the embodiments of the present application is to provide a magnetic field sensor and a multi-axis magnetic field sensor, which includes: a magnetic flux conversion module, a magnetic induction module and a differential detection module; the magnetic flux conversion module includes: a magnetic field input area, a magnetic field output area, a magnetic flux direction conversion area and a magnetic flux path connection area; the magnetic flux conversion module concentrates and amplifies the magnetic field to be measured in the magnetic field induction direction, and converts it into a magnetic field component in a spatial solid angle direction with an angle of 0-90 degrees with the direction of the magnetic field to be measured; the magnetic induction module senses the magnetic field at the air gap of the magnetic flux conversion module, generates a differential voltage signal and forms an output electrical signal to be measured through the differential detection module, which can realize the conversion of the magnetic field to be measured into a magnetic field component in the opposite direction at the air gap, thereby using a magnetic induction module with the same sensitivity direction to realize differential detection of a push-pull bridge structure, and can adopt integrated manufacturing, with a simple process, good sensitivity consistency, and easy production, thereby solving the problems of complex process, high cost, and poor sensitivity consistency of existing magnetic field sensors.

[0006] In a first aspect, an embodiment of the present application provides a magnetic field sensor, the sensor comprising: a magnetic flux conversion module, a magnetic induction module and a differential detection module; the differential detection module is electrically connected to the magnetic induction module; the magnetic flux conversion module comprises: a magnetic field input area, a magnetic field output area, a magnetic flux direction conversion area and a magnetic flux path connection area; the magnetic flux path connection area comprises: at least two air gaps located at different positions; the magnetic induction module comprises: at least two magnetic induction units; the magnetic flux path connection area connects the magnetic field input area, the magnetic field output area and the magnetic flux direction conversion area to form a magnetic circuit, and forms a magnetic induction direction. A magnetic flux path enters from the magnetic field input area and is output and connected to the magnetic field output area; the at least two magnetic induction units are correspondingly arranged at the at least two air gap positions, and the sensitivity direction of the magnetic induction unit is perpendicular to the vertical projection direction of the air gap; wherein the magnetic flux conversion module is used to guide the magnetic field to be measured along the magnetic induction direction to the magnetic flux path, and generate a differential magnetic field component in the air gap of the magnetic flux path; the magnetic induction module is used to generate a differential voltage signal according to the differential magnetic field component; the differential detection module is used to process the differential voltage signal and output the electrical signal to be measured.

[0007] In the above implementation process, the magnetic field to be measured in the magnetic field induction direction is concentrated and amplified by the magnetic flux conversion module, and converted into a magnetic field component in the spatial solid angle direction with an angle of 0-90 degrees with the direction of the magnetic field to be measured; the magnetic induction module senses the magnetic field at the air gap of the magnetic flux conversion module, generates a differential voltage signal and forms an output electrical signal to be measured through the differential detection module, which can realize the conversion of the magnetic field to be measured at the air gap into a magnetic field component in the opposite direction, thereby realizing differential detection of the push-pull bridge structure using a magnetic induction module with the same sensitivity direction, and can adopt integrated manufacturing, with a simple process, good sensitivity consistency, and easy production.

[0008] Optionally, the magnetic flux conversion module includes: a magnetic field input area, a magnetic field output area, at least three magnetic flux direction conversion areas and at least two magnetic flux path connection areas; the at least three magnetic flux direction conversion areas are located in the corner area of ​​the magnetic flux conversion module, and the at least two magnetic flux path connection areas connect the two adjacent corner areas, and form a single connected magnetic flux path with the magnetic field input area and the magnetic field output area in the magnetic induction direction; wherein, the at least two magnetic induction units are used to form the magnetic resistance of a push-pull half-bridge or push-pull full-bridge structure circuit, and sense the magnetic field to be measured in the magnetic induction direction to generate a differential voltage signal.

[0009] In the above implementation process, after the magnetic field to be measured is concentrated, amplified, and magnetically distorted, a single (or series) magnetic flux path is used to generate positive and negative magnetic field components at two different air gap locations, forming a differential magnetic field. A push-pull half-bridge structure is then used to generate a differential voltage signal, which is then converted into an output electrical signal through an open-loop signal conditioning circuit. The advantage of this method is that push-pull half-bridge measurement can be achieved using only magnetic induction units with the same sensitivity direction, avoiding the angular deviation and zero point offset issues caused by using different sensitivity directions in the prior art. This method achieves good sensitivity consistency and high measurement accuracy. Furthermore, the process is simple, low-cost, and can be integrated on a single chip, resulting in a small size and excellent stability.

[0010] Optionally, the magnetic flux conversion module includes: a magnetic field input area, a magnetic field output area, at least four magnetic flux direction conversion areas and at least four magnetic flux path connection areas; the at least four magnetic flux direction conversion areas are located in the corner area of ​​the magnetic flux conversion module, and the at least four magnetic flux path connection areas connect two adjacent corner areas, and form two connected magnetic flux paths with the magnetic field input area and the magnetic field output area in the magnetic induction direction; wherein, the at least two magnetic induction units are used to form the magnetic resistance of a push-pull half-bridge or push-pull full-bridge structure circuit, and sense the magnetic field to be measured in the magnetic induction direction to generate a differential voltage signal.

[0011] In the above implementation, two magnetic flux conversion modules with mirror-symmetrical single magnetic flux paths are superimposed in parallel. After the magnetic field to be measured is concentrated, amplified, and distorted, two mirror-symmetrical parallel magnetic flux paths are formed. Positive and negative magnetic field components with opposite directions are generated at four different air gaps, forming a differential magnetic field. A push-pull full-bridge structure is used to generate a differential voltage signal, which is then converted into an output electrical signal through an open-loop signal conditioning circuit. This advantage is that push-pull full-bridge measurement can be achieved using only magnetic induction units with a single sensitivity direction, enabling single-chip integrated manufacturing, further enhancing the magnetic focusing effect, improving sensitivity, and reducing noise.

[0012] Optionally, the magnetic induction module further includes: a magnetically shielded reference magnetic induction unit; the magnetically shielded reference magnetic induction unit is located within the vertical projection range of the magnetic flux conversion module; the at least two magnetic induction units are used to form a magnetic resistance of a push-pull half-bridge or push-pull full-bridge structure circuit, sensing the magnetic field to be measured in the magnetic induction direction to generate a differential voltage signal; or the at least one magnetic induction unit and the magnetically shielded reference magnetic induction unit are used to form a magnetic resistance of a differential half-bridge or differential full-bridge structure circuit, sensing the magnetic field to be measured in the magnetic induction direction to generate a differential voltage signal.

[0013] In the above implementation process, by partially merging the discrete metal soft magnetic materials where the two parallel magnetic circuits are located, it helps to increase stability and reduce volume. At the same time, a magnetic induction unit located within the vertical projection range of the metal soft magnetic material of the magnetic flux conversion module is added as a magnetic shielding reference magnetic induction unit, which can form a differential half-bridge or differential full-bridge structure to sense the magnetic field to be measured, helping to adjust and expand the measurement range of the magnetic field sensor. Among them, the magnetic shielding reference magnetic induction unit is adjacent to the magnetic induction unit at the air gap projection, and both are set near the air gap in the magnetic flux path connection area, which helps to enhance consistency and reduce zero-point drift.

[0014] Optionally, the flux conversion module also includes: a flux shielding soft magnetic path; the flux shielding soft magnetic path connects two flux path connection areas of the at least four flux path connection areas that are relatively arranged along the magnetic induction direction; the flux shielding soft magnetic path is used to shield or separate the flux path connection areas with air gaps.

[0015] In this implementation, the addition of a flux-shielding soft magnetic path mitigates the impact of the measured magnetic field on the magnetic field sensor's operating range, significantly increasing the sensor's operating range under the measured magnetic field and improving the sensitivity consistency of the magnetic sensing units. Furthermore, the magnetic sensing unit serving as the magnetic shielding reference unit is no longer located adjacent to the magnetic sensing unit at the air gap projection. Instead, it is located in a location with a larger coverage area of ​​the metal soft magnetic material, enhancing the magnetic shielding effect and making its resistance value more stable.

[0016] Optionally, the flux conversion module includes: at least two magnetic field input areas and at least two magnetic field output areas; the flux shielding soft magnetic path connects two adjacent magnetic field input areas of the at least two magnetic field input areas, and the flux shielding soft magnetic path connects two adjacent magnetic field output areas of the at least two magnetic field output areas; the flux shielding soft magnetic path is used to shield or divide the magnetic flux path connection area with an air gap.

[0017] In the above implementation process, by adding a new magnetic flux shielding soft magnetic path and increasing the spacing distance between the soft magnetic materials where the magnetic induction module is located, the isolation effect of the magnetic field to be measured can be further increased, the shielding or magnetic separation can be strengthened, and the influence of the magnetic field to be measured on the working range of the magnetic field sensor can be solved. The working range of the magnetic field sensor under the magnetic field to be measured is significantly increased, and the sensitivity consistency of the magnetic induction module is improved.

[0018] Optionally, the magnetic flux conversion module and the magnetic induction module are arranged on the same circuit chip using a chip integration process.

[0019] In the above implementation process, the magnetic flux conversion module and the magnetic induction unit are processed on the same chip by adopting a single chip integration preparation process, thereby reducing costs.

[0020] Optionally, the soft magnetic materials of any two of the magnetic field input area, the magnetic field output area, the magnetic flux direction conversion area, and the magnetic flux path connection area are arranged on the same plane.

[0021] In the above implementation process, by arranging any two parts of soft magnetic materials constituting the magnetic flux path in the magnetic flux conversion module on the same plane, the technical difficulty is reduced and it can meet the needs of more scenarios.

[0022] Optionally, the differential detection module includes: an open-loop signal conditioning circuit; the open-loop signal conditioning circuit is electrically connected to the magnetic induction unit; the open-loop signal conditioning circuit is used to condition and amplify the differential voltage signal and / or perform temperature compensation and / or linearity correction.

[0023] In the above implementation process, open-loop detection is achieved by adopting an open-loop signal conditioning circuit for conditioning amplification, temperature compensation and linearity correction, thereby improving detection accuracy and achieving better linearity.

[0024] Optionally, the differential detection module includes: a closed-loop signal conditioning circuit and a magnetic field feedback coil; the closed-loop signal conditioning circuit is electrically connected to the magnetic induction unit; the closed-loop signal conditioning circuit, the magnetic field feedback coil and the magnetic induction unit constitute a closed-loop magnetic field feedback structure; the closed-loop signal conditioning circuit is used to condition and amplify the differential voltage signal; the magnetic field feedback coil is used to generate a feedback magnetic field according to the conditioned and amplified signal to achieve dynamic balance of the magnetic field, and sample the current in the magnetic field feedback coil to form the electrical signal to be measured.

[0025] In the above implementation process, closed-loop negative feedback is achieved by adopting a closed-loop signal conditioning circuit and a magnetic field feedback coil for differential detection, thereby improving accuracy and achieving good linearity.

[0026] In a second aspect, an embodiment of the present application provides a multi-axis magnetic field sensor, which includes: any of the above-mentioned magnetic field sensors in a plurality of combinations; the magnetic field sensing directions of the magnetic flux conversion module in any of the above-mentioned magnetic field sensors in the plurality of combinations are multiple; and the magnetic flux conversion module is used to perform differential detection on the corresponding magnetic field to be measured in any of the above-mentioned magnetic field sensing directions.

[0027] In the above implementation process, by setting up a multi-axis sensor, not only can the magnetic induction modules and measurement methods of the multi-axis directions be flexibly and independently selected, but the magnetic flux conversion module in any direction has the effect of focusing, amplifying and guiding the magnetic path of the magnetic field to be measured in its own magnetic field induction direction, thereby shielding or dividing the magnetic induction modules in other magnetic field induction directions, increasing the working range of the magnetic field sensor and improving flexibility. BRIEF DESCRIPTION OF THE DRAWINGS

[0028] In order to more clearly illustrate the technical solutions of the embodiments of the present application, the following is a brief introduction to the drawings required for use in the embodiments of the present application. It should be understood that the following drawings only show certain embodiments of the present application and therefore should not be regarded as limiting the scope. For ordinary technicians in this field, other relevant drawings can be obtained based on these drawings without creative work.

[0029] FIG1 is a schematic diagram of a module structure of a magnetic field sensor according to an embodiment of the present application;

[0030] FIG2 is a partial cross-sectional schematic diagram of a first magnetic field sensor according to an embodiment of the present application;

[0031] FIG3 is a partial cross-sectional schematic diagram of a second magnetic field sensor according to an embodiment of the present application;

[0032] FIG4 is a simulation diagram of the magnetic flux path of the second magnetic field sensor according to an embodiment of the present application applying a magnetic field to be measured in the Y-axis direction;

[0033] FIG5 is a partial cross-sectional schematic diagram of a third magnetic field sensor according to an embodiment of the present application;

[0034] FIG6 is a magnetic flux path simulation diagram of a third magnetic field sensor according to an embodiment of the present application applying a magnetic field to be measured in the X-axis direction;

[0035] FIG7 is a partial cross-sectional schematic diagram of a fourth magnetic field sensor according to an embodiment of the present application;

[0036] FIG8 is a partial cross-sectional schematic diagram of a fifth magnetic field sensor according to an embodiment of the present application;

[0037] FIG9 is a partial cross-sectional schematic diagram of a sixth magnetic field sensor according to an embodiment of the present application;

[0038] FIG10 is a partial cross-sectional schematic diagram of a seventh magnetic field sensor according to an embodiment of the present application;

[0039] FIG11 is a simulation diagram of the magnetic flux path of the seventh magnetic field sensor according to an embodiment of the present application applying a magnetic field to be measured in the X-axis direction;

[0040] FIG12 is a simulation diagram of the magnetic flux path when a magnetic field in the Y-axis direction is applied by the seventh magnetic field sensor according to an embodiment of the present application;

[0041] FIG13 is a partial cross-sectional schematic diagram of an eighth magnetic field sensor according to an embodiment of the present application;

[0042] FIG14 is a simulation diagram of the magnetic flux path when the eighth magnetic field sensor according to an embodiment of the present application applies a magnetic field in the Y-axis direction;

[0043] FIG15 is a schematic diagram of a voltage-magnetic field curve of a tunnel magnetoresistance TMR according to an embodiment of the present application;

[0044] FIG16 is a partial cross-sectional schematic diagram of a ninth magnetic field sensor according to an embodiment of the present application;

[0045] FIG17 is a schematic structural diagram of a first multi-axis magnetic field sensor according to an embodiment of the present application;

[0046] FIG18 is a structural schematic diagram and three-view diagram of a second multi-axis magnetic field sensor according to an embodiment of the present application;

[0047] FIG19 is a structural schematic diagram and three-view diagram of a third multi-axis magnetic field sensor according to an embodiment of the present application.

[0048] Icon: 01-magnetic field sensor; 10-magnetic flux conversion module; 20-magnetic induction module; 30-differential detection module; 02-multi-axis magnetic field sensor. DETAILED DESCRIPTION

[0049] The technical solutions in the embodiments of the present application will be clearly and completely described below in conjunction with the drawings in the embodiments of the present application. Obviously, the described embodiments are only a part of the embodiments of the present application, rather than all of the embodiments. The components of the embodiments of the present application generally described and shown in the drawings here can be arranged and designed in various different configurations. Therefore, the following detailed description of the embodiments of the present application provided in the drawings is not intended to limit the scope of the application for protection, but merely represents the selected embodiments of the present application. Based on the embodiments of the present application, all other embodiments obtained by those skilled in the art without making creative work fall within the scope of protection of the present application.

[0050] It should be noted that similar numbers and letters represent similar items in the following figures, so once an item is defined in one figure, it does not need to be further defined and explained in subsequent figures. The terms "comprises", "comprising" or any other variations thereof are intended to cover non-exclusive inclusion, so that a process, method, article or device comprising a series of elements includes not only those elements, but also other elements not explicitly listed, or also includes elements inherent to such process, method, article or device. In the absence of further restrictions, an element defined by the statement "comprising a..." does not exclude the presence of additional identical elements in the process, method, article or device comprising the element. The terms "first", "second", etc. are merely used to distinguish one entity or operation from another entity or operation, and do not necessarily require or imply any such actual relationship or order between these entities or operations.

[0051] The inventors of this application have noticed that the common measurement method of magnetic field sensors is to use a bridge structure for differential detection to generate a voltage output, and to sense the magnetic field to be measured through a differential full bridge, a differential half bridge, a push-pull full bridge, and a push-pull half bridge. Among them, the push-pull bridge magnetic sensor has higher sensitivity and lower temperature drift than the differential bridge magnetic sensor using a single resistor or a reference resistor. In order to form a differential detection structure, the magnetic induction unit used in the existing sensor usually has two opposite sensitivity directions. The implementation method includes: (1) using separate push arm and wrist arm slices and setting them in a specific position, that is, first manufacturing a magnetic induction unit with a single sensitivity direction, and rotating one of the slices 180 degrees relative to the other slice to form a push arm and wrist arm with opposite sensitivity directions, and then connecting the slices of the push arm and wrist arm in the form of flying wires; its advantages are simple preparation method and low cost, but its disadvantages are that it is necessary to operate the two slices for precise positioning in the same plane, which is prone to angle deviation and zero point offset, affecting sensitivity consistency and measurement accuracy. (2) By designing a ferromagnetic reference layer with a multilayer thin film structure, by changing the number of layers of the multilayer thin film composed of the ferromagnetic layer and the metal spacer layer that are interactively coupled with the antiferromagnetic layer, one of which is an odd number of layers and the other is an even number of layers, the push magnetoresistance sensing unit and the pull magnetoresistance sensing unit of the opposite ferromagnetic reference layer can be manufactured. The disadvantage is that at least two multilayer thin film structures need to be introduced when depositing the multilayer thin film, which increases the complexity of the micromachining process. (3) By adopting the laser programmable heating magnetic field annealing method, the magnetoresistance sensing unit can be scanned and the antiferromagnetic layer can be quickly heated to above the blocking temperature. At the same time, during the cooling process, a magnetic field can be applied in any direction, and the magnetoresistance sensing unit can be oriented in the magnetic field sensitive direction in any direction by scanning one by one. By using this method, four orthogonally oriented magnetoresistance sensing units and their arrays can be manufactured on a single slice. However, the disadvantage is that it requires specific equipment, the process is complex, and the cost is high. Furthermore, to improve the sensitivity of the magnetic sensor and reduce noise, a soft magnetic flux concentrator is used to focus and amplify the magnetic field to be measured, thereby enhancing signal output. The soft magnetic flux concentrator also distorts the direction of the magnetic field to be measured. In view of this, the present application provides a magnetic field sensor 01 and a multi-axis magnetic field sensor 02 as described below.

[0052] Please refer to Figure 1, which is a schematic diagram of the module structure of a magnetic field sensor 01 provided in an embodiment of the present application. The embodiment of the present application is explained in detail below. The sensor includes: a magnetic flux conversion module 10, a magnetic induction module 20, and a differential detection module 30; the magnetic flux conversion module 10 includes: a magnetic field input area, a magnetic field output area, a magnetic flux direction conversion area, and a magnetic flux path connection area; the magnetic flux path connection area includes: at least two air gaps located at different positions; the magnetic induction module 20 includes: at least two magnetic induction units;

[0053] The differential detection module 30 is electrically connected to the magnetic induction module 20; the magnetic flux path connection area magnetically connects the magnetic field input area, the magnetic field output area, and the magnetic flux direction conversion area, and forms a magnetic flux path that enters from the magnetic field input area in the magnetic induction direction, outputs from the magnetic field output area, and connects; at least two magnetic induction units are correspondingly arranged at at least two air gap positions, and the sensitivity direction of the magnetic induction unit is perpendicular to the vertical projection direction of the air gap; wherein, the magnetic flux conversion module 10 is used to guide the magnetic field to be measured along the magnetic induction direction to the magnetic flux path, and generate a differential magnetic field component in the air gap of the magnetic flux path; the magnetic induction module 20 is used to generate a differential voltage signal according to the differential magnetic field component; the differential detection module 30 is used to process the differential voltage signal and output the electrical signal to be measured.

[0054] Exemplarily, the magnetic flux conversion module 10 may be: composed of a metallic soft magnetic material with high magnetic permeability, and the magnetic flux path of the magnetic flux conversion module 10 is formed by the magnetic conductivity of the soft magnetic material with high magnetic permeability, and the magnetic field to be measured in the magnetic field induction direction will undergo a magnetic field direction conversion through the magnetic flux path; the magnetic flux conversion module 10 may specifically include a magnetic field input area, a magnetic field output area, a magnetic flux direction conversion area, and a magnetic flux path connection area, and the magnetic flux path connection area magnetically connects the soft magnetic flux paths of the magnetic field input area, the magnetic field output area, and the magnetic flux direction conversion area; in the magnetic field induction direction, the magnetic flux path is parallel to the magnetic flux conversion module 10 is located in the plane and enters from the magnetic field input area and outputs from the magnetic field output area. When the magnetic field direction is converted, the angle between the magnetic flux path of the magnetic flux direction conversion area and the magnetic flux path connection area and the magnetic field to be measured is a spatial solid angle of 0-90 degrees; the magnetic flux direction conversion area and / or the magnetic flux path connection area is provided with one or more air gaps, the air gaps intersecting with the magnetic field direction of the magnetic flux direction conversion area and / or the magnetic flux path connection area, the magnetic flux path formed by the air gaps and the magnetic flux path formed by the soft magnetic material together constitute the magnetic flux path of the magnetic flux direction conversion area and / or the magnetic flux path connection area, and the magnetic path direction of the magnetic flux path connection area is perpendicular to the air gap. The number of magnetic field input areas can be one or more, the number of magnetic field output areas can be one or more, the number of magnetic flux direction conversion areas can be one or more, and the number of magnetic flux path connection areas can be one or more; the magnetic field input area and the magnetic field output area can be independent of each other or connected in series and parallel magnetic circuits, and the structures of the magnetic flux direction conversion areas can be the same or different. The magnetic induction module 20 can be: two or more giant magneto-impedance (GMI) sensors, fluxgate sensors, Hall sensors, anomalous Hall sensors (AHE) sensors, or magnetoresistive (MR) sensors (magnetic induction units) with their vertical projections located at the air gap of the magnetic flux conversion module 10. For the MR sensors, the magnetic induction module 20 can be composed of one or more MR sensors connected in series and parallel, each of which is one of anisotropic MR (AMR), giant MR (GMR), tunnel MR (TMR), perpendicular tunnel MR (PTMR), and giant MR (CMR). The differential detection module 30 can be: an open-loop signal conditioning circuit or a closed-loop signal conditioning circuit, which conditions, amplifies, temperature compensates, and linearizes the differential voltage signal to form the output electrical signal to be measured by the magnetic field sensor 01.

[0055] Optionally, as shown in Figure 2, the magnetic field sensor 01 includes a magnetic flux conversion module 10, a magnetic induction module 20, and a differential detection module 30. The magnetic flux conversion module 10 in the magnetic field sensor 01 has a single-plane single magnetic field sensing direction, and the magnetic field sensing direction is the same as that of the magnetic flux conversion module 10, which is the X-axis direction. The magnetic flux conversion module 10 can adopt: two magnetic field input areas 1a, 1b, two magnetic field output areas 2a, 2b, eight magnetic flux direction conversion areas 3a, 3b, 3c, 3d, 3e, 3f, 3g, 3h, six magnetic flux path connection areas 4a, 4b, 4c, 4d, 4e, 4f in the embodiment shown in Figure 2, and a magnetic flux shielding soft magnetic path 6 can be added; the magnetic induction module 20 can adopt: four magnetic induction units 5a, 5b, 5c, 5d, the sensitivity direction of all magnetic induction units is the positive direction of the Y axis, and the vertical projections of the magnetic induction units 5a, 5b, 5c, 5d are respectively located at the air gap positions of the magnetic flux path connection areas 4a, 4c, 4d, 4f of the magnetic flux conversion module 10. The metal soft magnetic material constituting the flux conversion module 10 is distributed in the XY plane. Taking the magnetic field to be measured in the positive direction of the X-axis as an example, in this case, the magnetic field input areas 1a and 1b are located at one end in the negative direction of the X-axis, and the magnetic field output areas 2a and 2b are located at one end in the positive direction of the X-axis; the flux direction conversion areas 3a and 3g are corners pointing to the negative direction of the X-axis and the positive direction of the Y-axis, the flux direction conversion areas 3b and 3h are corners pointing to the positive direction of the X-axis and the negative direction of the Y-axis, the flux direction conversion areas 3c and 3e are corners pointing to the negative direction of the X-axis and the negative direction of the Y-axis, and the flux direction conversion areas 3d and 3f are corners pointing to the positive direction of the X-axis and the positive direction of the Y-axis. The magnetic flux path connection area 4a is connected to the magnetic flux direction conversion areas 3a and 3b in the Y-axis direction, the magnetic flux path connection area 4b includes three ports pointing to the positive direction of the X-axis, the negative direction of the X-axis, and the negative direction of the Y-axis, the magnetic flux path connection area 4c is connected to the magnetic flux direction conversion areas 3c and 3d in the Y-axis direction, the magnetic flux path connection area 4d is connected to the magnetic flux direction conversion areas 3e and 3f in the Y-axis direction, the magnetic flux path connection area 4e includes three ports pointing to the positive direction of the X-axis, the negative direction of the X-axis, and the positive direction of the Y-axis, and the magnetic flux path connection area 4f is connected to the magnetic flux direction conversion areas 3g and 3h in the Y-axis direction; the magnetic flux shielding soft magnetic path 6 is connected to the magnetic flux path connection areas 4b and 4e in the Y-axis direction; and the magnetic flux path connection areas 4a, 4c, 4d, and 4f are respectively provided with two air gaps that pass through the metal soft magnetic material along the X-axis direction.

[0056] The magnetic field to be measured is amplified by the metallic soft magnetic material of the magnetic flux conversion module 10 to form a magnetic circuit. The magnetic circuit is then twisted on both sides to the positive and negative directions of the Y-axis, forming two parallel magnetic flux paths. The two magnetic paths are then twisted in the Y-axis direction and then twisted back to the positive direction of the X-axis. The magnetic field to be measured generates a magnetic field component in the positive direction of the Y-axis at the air gap between the magnetic flux path connection areas 4a and 4f, and a magnetic field component in the negative direction of the Y-axis at the air gap between the magnetic flux path connection areas 4c and 4d. This creates a differential magnetic field. Since the sensitivity of the magnetic induction units 5a, 5b, 5c, and 5d is all in the positive direction of the Y-axis, the resistance of the magnetic induction units 5a and 5d decreases, while the resistance of the magnetic induction units 5b and 5c increases. Therefore, a series-parallel push-pull half-bridge or full-bridge structure can be selected to sense the magnetic field in the positive direction of the X-axis and generate a differential voltage signal. An open-loop signal conditioning circuit can be used to condition, amplify, temperature-compensate, and linearize the differential voltage signal to form the output electrical signal of the magnetic field sensor 01. Specifically, when the magnetic field to be measured is in the positive Y-axis direction, the flux-shielding soft magnetic path 6 can concentrate and guide the magnetic field in the Y-axis direction, thereby shielding or dividing the magnetic flux path connection area with an air gap.

[0057] Among them, the magnetic flux conversion module 10 and its magnetic field sensor 01 of the present application are applicable to both magnetic induction units with a sensitivity direction parallel to the plane in which they are located and magnetic induction units with a sensitivity direction perpendicular to the plane in which they are located. The magnetic induction unit used can be a Hall element with a sensitivity direction (the direction pointed by the "Sen" arrow in Figure 2) perpendicular to the plane in which they are located. In this case, the Hall element is located in the XZ plane, and its sensitivity direction is the positive direction of the Y axis. Other magnetic induction units with a sensitivity direction perpendicular to the plane in which they are located, such as perpendicular tunnel magnetoresistors (PTMRs), can adopt a similar structure, and are fixed perpendicularly to the air gap of the magnetic flux conversion module 10 located in the XY plane along the XZ plane to form the magnetic field sensor 01. The magnetic induction unit used can also be a tunnel magnetoresistors (TMRs) with a sensitivity direction (the direction pointed by the "Sen" arrow in Figure 2) parallel to the plane in which they are located. In this case, the tunnel magnetoresistors (TMRs) are located in the XY plane, and their sensitivity direction is the positive direction of the Y axis. Other magnetic induction units with a sensitivity direction perpendicular to the plane in which they are located, such as giant magnetoresistors (GMRs), can adopt a similar structure, and the magnetic induction unit is arranged parallel to the plane in which the magnetic flux conversion module 10 is located to form the magnetic field sensor 01.

[0058] The magnetic field to be measured in the magnetic field induction direction is concentrated and amplified by the magnetic flux conversion module 10, and converted into a magnetic field component in the spatial solid angle direction with an angle of 0-90 degrees with the direction of the magnetic field to be measured; the magnetic induction module 20 senses the magnetic field at the air gap of the magnetic flux conversion module 10, generates a differential voltage signal and forms an output electrical signal to be measured through the differential detection module 30, which can realize the conversion of the magnetic field to be measured into a magnetic field component in the opposite direction at the air gap, thereby realizing differential detection of the push-pull bridge structure using the magnetic induction module 20 with the same sensitivity direction, and can adopt integrated manufacturing, with simple process, good sensitivity consistency, and easy production.

[0059] In one embodiment, the magnetic flux conversion module 10 includes: a magnetic field input area, a magnetic field output area, at least three magnetic flux direction conversion areas and at least two magnetic flux path connection areas; at least three magnetic flux direction conversion areas are located in the corner area of ​​the magnetic flux conversion module 10, and at least two magnetic flux path connection areas connect two adjacent corner areas, and form a single connected magnetic flux path with the magnetic field input area and the magnetic field output area in the magnetic induction direction; wherein, at least two magnetic induction units are used to form a magnetic resistance of a push-pull half-bridge or push-pull full-bridge structure circuit, and sense the magnetic field to be measured in the magnetic induction direction to generate a differential voltage signal.

[0060] For example, as shown in FIG3 , the magnetic field sensor 01 includes a magnetic flux conversion module 10, a magnetic induction module 20, and a differential detection module 30. The magnetic field sensing direction of the magnetic field sensor 01 is the same as that of the magnetic flux conversion module 10, which is the Y-axis direction. The magnetic flux conversion module 10 is a single-plane structure with a single magnetic field sensing direction made of a metallic soft magnetic material with high magnetic permeability. It may include: a magnetic field input area 1, a magnetic field output area 2, four magnetic flux direction conversion areas 3a, 3b, 3c, 3d, and three magnetic flux path connection areas 4a, 4b, 4c, which together constitute a single connected magnetic flux path along the magnetic field sensing direction (Y-axis direction). The metallic soft magnetic material constituting the magnetic flux conversion module 10 may be distributed in the XY plane. The magnetic field to be measured is in the negative direction of the Y-axis as an example for explanation. The magnetic induction module 20 may include a magnetic induction unit 5a and a magnetic induction unit 5b. The sensitivity directions of the magnetic induction units 5a and 5b are both in the positive direction of the X-axis, and the vertical projection of the magnetic induction unit 5a is located at the air gap position of the magnetic flux path connection area 4a of the magnetic flux conversion module 10, and the vertical projection of the magnetic induction unit 5b is located at the air gap position of the magnetic flux path connection area 4c of the aforementioned magnetic flux conversion module 10. Therefore, the sensitivity direction of the magnetic induction unit 5 is perpendicular to the air gap. In this case, the magnetic field input area 1 and the magnetic field output area 2 are respectively located at one end in the positive direction of the Y axis and one end in the negative direction of the Y axis; the magnetic flux direction conversion area 3a is a corner pointing to the positive direction of the X axis and the positive direction of the Y axis, the magnetic flux direction conversion area 3b is a corner pointing to the negative direction of the X axis and the negative direction of the Y axis, the magnetic flux direction conversion area 3c is a corner pointing to the negative direction of the X axis and the positive direction of the Y axis, and the magnetic flux direction conversion area 3d is a corner pointing to the positive direction of the X axis and the negative direction of the Y axis; the magnetic flux path connection area 4a connects the magnetic flux direction conversion areas 3a and 3b in the X-axis direction, the magnetic flux path connection area 4b connects the magnetic flux direction conversion areas 3b and 3c in the Y-axis direction, and the magnetic flux path connection area 4c connects the magnetic flux direction conversion areas 3c and 3d in the X-axis direction, and the magnetic flux path connection areas 4a and 4c are respectively provided with two air gaps that penetrate the metal soft magnetic material along the Y-axis direction.

[0061] When the magnetic field to be measured is in the negative direction of the Y-axis, the metallic soft magnetic material gathers and amplifies the magnetic field to be measured and forms a magnetic flux path. The magnetic path enters the magnetic field input area 1 at one end in the positive direction of the Y-axis, and is then twisted to the positive direction of the X-axis by the magnetic flux direction conversion area 3a. It then passes through the magnetic flux path connection area 4a with an air gap along the positive direction of the X-axis and generates a magnetic field component in the positive direction of the X-axis in the air gap. The magnetic path then passes through the magnetic flux direction conversion area 3b, the magnetic flux path connection area 4b, and the magnetic flux direction conversion area 3c in sequence, twisting the magnetic path from the positive direction of the X-axis to the negative direction of the X-axis, and then passes through the magnetic flux path connection area 4c with an air gap and generates a magnetic field component in the negative direction of the X-axis in the air gap. In this way, the magnetic field to be measured in the Y-axis direction can generate opposite magnetic field components in the positive and negative directions of the X-axis at air gaps at different positions, forming a differential magnetic field. To achieve symmetry in magnetic field measurement between the positive and negative directions of the Y-axis, the magnetic circuit, after passing through the magnetic flux path connection area 4c, is twisted back to the negative direction of the Y-axis by the magnetic flux direction conversion area 3d, and then passes through the magnetic field output area 2. Here, the magnetic field input area 1 and the magnetic field output area 2 are completely equivalent and can be interchanged depending on the direction of the magnetic field to be measured. That is, for the same metallic soft magnetic material structure, the magnetic field input area 1 and the magnetic field output area 2 are only used to indicate and describe the direction of the measured magnetic field entering and exiting the magnetic flux conversion module 10. When the measured magnetic field reverses, the original magnetic field input area 1 and magnetic field output area 2 can be considered interchanged. In addition, although the magnetic flux path connection area magnetically connects the soft magnetic flux paths of the magnetic field input area 1, the magnetic field output area 2, and the magnetic flux direction conversion area, for the same metal soft magnetic material structure, there may be multiple situations for the actual definition of the magnetic flux path connection area; as shown in Figure 3, the magnetic field input area 1 and the magnetic flux direction conversion area 3a are defined as being directly connected, and can also be defined as having a section of the magnetic flux path connection area therein; and as shown in Figure 3, the magnetic flux direction conversion area 3b, the magnetic flux path connection area 4b, and the magnetic flux direction conversion area 3c are connected in sequence. When the corner distance between the magnetic flux direction conversion area 3b and the magnetic flux direction conversion area 3c is too close, the magnetic flux direction conversion areas 3b and 3c can be regarded as being directly connected; similarly, the part with an air gap in the metal soft magnetic material can be regarded as being located in the magnetic flux path connection area as well as being located on the magnetic flux direction conversion area.

[0062] As shown in FIG4 , from the magnetic flux path simulation diagram after the magnetic flux conversion module 10 in the embodiment of FIG3 is added with the magnetic field to be measured in the negative direction of the Y axis, it can be seen that the magnetic field to be measured is concentrated and amplified by the metal soft magnetic material to form a magnetic circuit, and a magnetic permeability offset of 0-90 degrees in the magnetic flux direction conversion areas 3a, 3b, 3c, and 3d occurs in sequence. It can be seen that the air gaps of the magnetic flux path connection areas 4a and 4c can generate obvious opposite magnetic field components in the positive and negative directions of the X axis, forming a differential magnetic field, and the magnetic flux paths passing through the air gaps are in a series relationship. Similarly, taking the case where the magnetic field to be measured is in the negative direction of the Y axis as an example, the concentrated and amplified magnetic circuit passes through the magnetic flux path connection area 4a with an air gap along the positive direction of the X axis, and then passes through the magnetic flux path connection area 4c with an air gap along the negative direction of the X axis; at this time, a magnetic field component in the positive direction of the X axis is generated in the air gap of the magnetic flux path connection area 4a, and a magnetic field component in the negative direction of the X axis is generated in the air gap of the magnetic flux path connection area 4c. Because the sensitivity of magnetic sensing units 5a and 5b is directed toward the positive X-axis, the resistance of magnetic sensing unit 5a decreases while the resistance of magnetic sensing unit 5b increases. Therefore, a push-pull half-bridge configuration can be used to sense the magnetic field in the negative Y-axis direction, generating a differential voltage signal. An open-loop signal conditioning circuit can be used to condition, amplify, temperature-compensate, and perform linearity correction on the differential voltage signal to form the output electrical signal to be measured by magnetic field sensor 01.

[0063] The magnetic induction unit 5 can adopt a giant magneto-impedance (GMI), a fluxgate, a Hall element, an anomalous Hall element (AHE), or a magnetoresistive (MR) sensitive element, depending on its placement and orientation. The MR sensitive element can be one or more series-parallel anisotropic magnetoresistive (AMR), giant magnetoresistive (GMR), tunnel magnetoresistive (TMR), perpendicular tunnel magnetoresistive (PTMR), and giant magnetoresistive (CMR). Specifically, when the sensitivity direction of the magnetic induction unit 5 is perpendicular to the plane in which it is located, the substrate on which the magnetic induction unit 5 is located is perpendicular to the plane in which the magnetic flux conversion module 10 is located. For example, if the magnetic flux conversion module 10 shown in FIG. 1 is located in the XY plane and is measured using a Hall element as an example, the substrate on which each Hall element is located is parallel to the YZ plane, and is then connected and fixed through basic components such as the substrate, lead pads, and a mechanical support housing. When the sensitivity direction of the magnetic induction unit 5 is parallel to the plane in which it is located, the substrate in which it is located is parallel to the plane in which the magnetic flux conversion module 10 is located. Since all the magnetic induction units can form a differential bridge or a push-pull bridge with only sensitivity in the same direction, when a magnetoresistive sensitive element with a sensitivity direction parallel to the plane in which it is located, such as a tunnel magnetoresistor TMR, is used, a magnetoresistive film can be prepared on the same layer at one time. Combined with the substrate, lead pads and mechanical support housing, single-chip preparation can be achieved.

[0064] After the magnetic field to be measured is concentrated, amplified, and magnetically distorted, it is then passed through a single (or even a single) series magnetic flux path to generate magnetic field components with opposite positive and negative directions at two different air gaps, forming a differential magnetic field. A push-pull half-bridge structure is then used to generate a differential voltage signal, which is then converted into an output electrical signal via an open-loop signal conditioning circuit. The advantage of this method is that push-pull half-bridge measurement can be achieved using only magnetic sensing units 5 with the same sensitivity direction, avoiding the angular deviation and zero point offset issues associated with using different sensitivity directions in the prior art. This method achieves good sensitivity consistency and high measurement accuracy. Furthermore, the process is simple, cost-effective, and single-chip integrated manufacturing is possible, resulting in a compact size and excellent stability.

[0065] In one embodiment, the magnetic flux conversion module 10 includes: a magnetic field input area, a magnetic field output area, at least four magnetic flux direction conversion areas and at least four magnetic flux path connection areas; at least four magnetic flux direction conversion areas are located in the corner area of ​​the magnetic flux conversion module 10, and at least four magnetic flux path connection areas connect two adjacent corner areas, and form two connected magnetic flux paths with the magnetic field input area and the magnetic field output area in the magnetic induction direction; wherein, at least two magnetic induction units are used to form a magnetic resistance of a push-pull half-bridge or push-pull full-bridge structure circuit, and sense the magnetic field to be measured in the magnetic induction direction to generate a differential voltage signal.

[0066] For example, as shown in FIG5 , the magnetic field sensor 01 includes a magnetic flux conversion module 10, a magnetic induction module 20, and a differential detection module 30. The magnetic field sensing direction of the magnetic field sensor 01 is the same as that of the magnetic flux conversion module 10, which is the X-axis direction. The magnetic flux conversion module 10 is equivalent to the parallel superposition of two mirror-symmetrical magnetic flux conversion modules 10 in FIG3 . The magnetic flux conversion module 10 has a single plane and a single magnetic field sensing direction, and may specifically include: two magnetic field input areas 1a and 1b, two magnetic field output areas 2a and 2b, eight magnetic flux direction conversion areas 3a, 3b, 3c, 3d, 3e, 3f, 3g, and 3h, and six magnetic flux path connection areas 4a, 4b, 4c, 4d, 4e, and 4f, which together constitute two connected magnetic flux paths along the magnetic field sensing direction (X-axis direction). The magnetic induction module 20 may include four magnetic induction units 5a, 5b, 5c, and 5d. The sensitivity of all magnetic induction units 5a, 5b, 5c, and 5d is directed toward the positive Y-axis. The vertical projections of the magnetic induction units 5a, 5b, 5c, and 5d are located at the air gaps of the magnetic flux path connection areas 4a, 4c, 4d, and 4f of the magnetic flux conversion module 10, respectively. Therefore, the sensitivity of the magnetic induction unit 5 is perpendicular to the air gap. The metallic soft magnetic material that constitutes the magnetic flux conversion module 10 is distributed in the XY plane. For example, the magnetic field to be measured is directed toward the positive X-axis. In this case, the magnetic field input areas 1a and 1b are located at the negative X-axis end, and the magnetic field output areas 2a and 2b are located at the positive X-axis end. The magnetic flux direction conversion zones 3a and 3g are corners pointing to the negative direction of the X-axis and the positive direction of the Y-axis, the magnetic flux direction conversion zones 3b and 3h are corners pointing to the positive direction of the X-axis and the negative direction of the Y-axis, the magnetic flux direction conversion zones 3c and 3e are corners pointing to the negative direction of the X-axis and the negative direction of the Y-axis, and the magnetic flux direction conversion zones 3d and 3f are corners pointing to the positive direction of the X-axis and the positive direction of the Y-axis. The magnetic flux path connection area 4a is connected to the magnetic flux direction conversion areas 3a and 3b in the Y-axis direction, the magnetic flux path connection area 4b is connected to the magnetic flux direction conversion areas 3b and 3c in the X-axis direction, the magnetic flux path connection area 4c is connected to the magnetic flux direction conversion areas 3c and 3d in the Y-axis direction, the magnetic flux path connection area 4d is connected to the magnetic flux direction conversion areas 3e and 3f in the Y-axis direction, the magnetic flux path connection area 4e is connected to the magnetic flux direction conversion areas 3f and 3g in the X-axis direction, and the magnetic flux path connection area 4f is connected to the magnetic flux direction conversion areas 3g and 3h in the Y-axis direction; and the magnetic flux path connection areas 4a, 4c, 4d, and 4f are respectively provided with two air gaps that pass through the metal soft magnetic material along the X-axis direction.

[0067] When the magnetic field to be measured is in the positive direction of the X-axis, the metallic soft magnetic material concentrates and amplifies the magnetic field to be measured, forming two parallel magnetic flux paths that are mirror-symmetrical about the X-axis. One of the magnetic paths enters the magnetic field input area 1a at the negative end of the X-axis, is then twisted to the positive direction of the Y-axis by the magnetic flux direction conversion area 3a, and then passes through the magnetic flux path connection area 4a with an air gap along the positive direction of the Y-axis, generating a magnetic field component in the positive direction of the Y-axis in the air gap. The magnetic path then passes through the magnetic flux direction conversion area 3b, the magnetic flux path connection area 4b, and the magnetic flux direction conversion area 3c in sequence, twisting the magnetic path from the positive direction of the Y-axis to the negative direction of the Y-axis, and then passes through the magnetic flux path connection area 4c with an air gap, generating a magnetic field component in the negative direction of the Y-axis in the air gap. In this way, the magnetic field to be measured in the X-axis direction can generate opposite magnetic field components in the positive and negative directions of the Y-axis at different air gaps, forming a differential magnetic field. In order to achieve symmetry in the magnetic field measurement in the positive and negative directions of the X-axis, the magnetic circuit passes through the magnetic flux path connection area 4c, is twisted back to the positive direction of the X-axis by the magnetic flux direction conversion area 3d, and then passes through the magnetic field output area 2a. Similarly, another magnetic circuit enters the magnetic field input area 1b at one end in the negative direction of the X-axis, and is then twisted to the negative direction of the Y-axis by the magnetic flux direction conversion area 3e, and then passes through the magnetic flux path connection area 4d with an air gap along the negative direction of the Y-axis, and generates a magnetic field component in the negative direction of the Y-axis in the air gap; the magnetic circuit then passes through the magnetic flux direction conversion area 3f, the magnetic flux path connection area 4e, and the magnetic flux direction conversion area 3g in sequence, twisting the magnetic circuit from the negative direction of the Y-axis to the positive direction of the Y-axis, and then passes through the magnetic flux path connection area 4f with an air gap, and generates a magnetic field component in the positive direction of the Y-axis in the air gap; thereby, the magnetic field to be measured in the X-axis direction can generate opposite magnetic field components in the positive and negative directions of the Y-axis at air gaps at different positions, forming a differential magnetic field; after passing through the magnetic flux path connection area 4f, the magnetic circuit is twisted back to the positive direction of the X-axis by the magnetic flux direction conversion area 3h, and then passes through the magnetic field output area 2a.

[0068] As shown in Figure 6, from the magnetic flux path simulation diagram after the magnetic flux conversion module 10 in the embodiment of Figure 5 is added with the magnetic field to be measured in the positive direction of the X-axis, it can be seen that: the magnetic field to be measured is gathered and amplified by the metal soft magnetic material to form a magnetic circuit, and magnetic conductivity deviation of 0-90 degrees in the magnetic flux direction conversion areas 3a, 3b, 3c, 3d and the magnetic flux direction conversion areas 3e, 3f, 3g, 3h occurs in turn. It can be seen that an obvious magnetic field component in the positive direction of the Y-axis can be generated at the air gap of the magnetic flux path connection areas 4a and 4f, and an obvious magnetic field component in the negative direction of the Y-axis can be generated at the air gap of the magnetic flux path connection areas 4c and 4d, thereby forming a differential magnetic field, and the magnetic flux path passing through the air gap is mirror-symmetrical about the X-axis and is two magnetic flux paths in a parallel relationship. After being focused and amplified, one magnetic path passes through the air-gapped magnetic flux path connection area 4a along the positive Y-axis direction, then passes through the air-gapped magnetic flux path connection area 4c along the negative Y-axis direction. The other magnetic path passes through the air-gapped magnetic flux path connection area 4d along the negative Y-axis direction, then passes through the air-gapped magnetic flux path connection area 4f along the positive Y-axis direction. At this point, the air gaps between the magnetic flux path connection areas 4a and 4f generate magnetic field components in the positive Y-axis direction, while the air gaps between the magnetic flux path connection areas 4c and 4d generate magnetic field components in the negative Y-axis direction. Because the sensitivity of magnetic sensing units 5a, 5b, 5c, and 5d is all in the positive Y-axis direction, the resistance of magnetic sensing units 5a and 5d decreases, while the resistance of magnetic sensing units 5b and 5c increases. Therefore, a push-pull full-bridge structure can be used to sense the magnetic field in the positive X-axis direction, generating a differential voltage signal. An open-loop signal conditioning circuit can be used to condition, amplify, temperature-compensate, and perform linearity correction on the differential voltage signal to form the output electrical signal to be measured by the magnetic field sensor 01.

[0069] Optionally, Figure 7 shows a schematic diagram of a flux conversion module 10 and a magnetic field sensor 01 of another structure that is mirror-symmetrical about the X-axis. The measurement principle of this structure is basically the same as the structure shown in Figure 5, and is also equivalent to the parallel superposition of two mirror-symmetrical flux conversion module 10 structures in Figure 3, with only the superposition position being translated and exchanged in the Y-axis direction. The measurement principle will not be repeated here. Assuming that the magnetic field to be measured is in the positive direction of the X-axis, the magnetic circuit on the positive direction side of the Y-axis passes through the magnetic field input area 1a, the magnetic flux direction conversion area 3a, the magnetic flux path connection area 4a, the magnetic flux direction conversion area 3b, the magnetic flux path connection area 4b, the magnetic flux direction conversion area 3c, the magnetic flux path connection area 4c, the magnetic flux direction conversion area 3d, and the magnetic field output area 2a in sequence; the magnetic circuit on the negative direction side of the Y-axis passes through the magnetic field input area 1b, the magnetic flux direction conversion area 3e, the magnetic flux path connection area 4d, the magnetic flux direction conversion area 3f, the magnetic flux path connection area 4e, the magnetic flux direction conversion area 3g, the magnetic flux path connection area 4f, the magnetic flux direction conversion area 3h, and the magnetic field output area 2b in sequence; and the vertical projections of the magnetic induction units 5a, 5b, 5c, and 5d are respectively located at the air gap positions of the flux path connection areas 4a, 4c, 4d, and 4f.

[0070] By employing two magnetic flux conversion modules 10 with mirror-symmetrical single magnetic flux paths in parallel and superimposed, the magnetic field to be measured undergoes amplification and magnetic circuit distortion, forming two mirror-symmetrical parallel magnetic flux paths. This generates positive and negative magnetic field components in opposite directions at four different air gap locations, forming a differential magnetic field. A push-pull full-bridge structure is then used to generate a differential voltage signal, which is then converted into an output electrical signal via an open-loop signal conditioning circuit. This advantageously allows push-pull full-bridge measurement using only magnetic sensing units with a single sensitivity direction, enabling single-chip integrated manufacturing, further enhancing magnetic field concentration, improving sensitivity, and reducing noise.

[0071] In one embodiment, the magnetic induction module 20 further includes: a magnetically shielded reference magnetic induction unit; the magnetically shielded reference magnetic induction unit is located within the vertical projection range of the magnetic flux conversion module 10; at least two magnetic induction units are used to form a magnetic resistance of a push-pull half-bridge or push-pull full-bridge structure circuit, sensing the magnetic field to be measured in the magnetic induction direction to generate a differential voltage signal; or at least one magnetic induction unit and the magnetically shielded reference magnetic induction unit are used to form a magnetic resistance of a differential half-bridge or differential full-bridge structure circuit, sensing the magnetic field to be measured in the magnetic induction direction to generate a differential voltage signal.

[0072] For example, as shown in FIG8 , the magnetic field sensor 01 includes a magnetic flux conversion module 10, a magnetic induction module 20, and a differential detection module 30. The magnetic field sensing direction of the magnetic field sensor 01 is the same as that of the magnetic flux conversion module 10, which is the X-axis direction. The magnetic flux conversion module 10 is a single-plane, single-magnetic field sensing module and may include: a magnetic field input region 1, a magnetic field output region 2, six magnetic flux direction conversion regions 3a, 3b, 3c, 3d, 3e, 3f, and six magnetic flux path connection regions 4a, 4b, 4c, 4d, 4e, 4f, which together form two connected magnetic flux paths along the magnetic field sensing direction (X-axis direction). The magnetic induction module 20 may include magnetic induction units 5a1, 5b1, 5c1, 5d1, 5a2, 5b2, 5c2, and 5d2. The sensitivity direction of all magnetic induction units 5 is the positive Y-axis direction. The vertical projections of the magnetic induction units 5a1, 5b1, 5c1, and 5d1 are respectively located at the air gap positions of the magnetic flux path connection areas 4a, 4c, 4d, and 4f of the magnetic flux conversion module 10. The magnetic induction units 5a2, 5b2, 5c2, and 5d2 are located within the vertical projection range of the metal soft magnetic material of the magnetic flux conversion module 10 and serve as magnetic shielding reference magnetic induction units. The magnetic shielding reference magnetic induction units are adjacent to the magnetic induction units at the air gap projections and are all located near the air gap in the magnetic flux path connection area. The magnetic field induction direction is the X-axis direction. The metal soft magnetic material constituting the magnetic flux conversion module 10 is distributed in the XY plane. For the purpose of explanation, the magnetic field to be measured is in the positive X-axis direction. In this case, the magnetic field input area 1 is located at the negative X-axis end. The magnetic field output area 2 is located at one end of the positive direction of the X-axis; the magnetic flux direction conversion area 3a includes three ports pointing to the negative direction of the X-axis, the positive direction of the Y-axis, and the negative direction of the Y-axis; the magnetic flux direction conversion area 3b is a corner pointing to the positive direction of the X-axis and the negative direction of the Y-axis; the magnetic flux direction conversion area 3c is a corner pointing to the negative direction of the X-axis and the negative direction of the Y-axis; the magnetic flux direction conversion area 3d includes three ports pointing to the positive direction of the X-axis, the positive direction of the Y-axis, and the negative direction of the Y-axis; the magnetic flux direction conversion area 3e is a corner pointing to the positive direction of the X-axis and the positive direction of the Y-axis; and the magnetic flux direction conversion area 3f is a corner pointing to the negative direction of the X-axis and the positive direction of the Y-axis. The magnetic flux path connection area 4a is connected to the magnetic flux direction conversion areas 3a and 3b in the Y-axis direction, the magnetic flux path connection area 4b is connected to the magnetic flux direction conversion areas 3b and 3c in the X-axis direction, the magnetic flux path connection area 4c is connected to the magnetic flux direction conversion areas 3c and 3d in the Y-axis direction, the magnetic flux path connection area 4d is connected to the magnetic flux direction conversion areas 3a and 3e in the Y-axis direction, the magnetic flux path connection area 4e is connected to the magnetic flux direction conversion areas 3e and 3f in the X-axis direction, and the magnetic flux path connection area 4f is connected to the magnetic flux direction conversion areas 3d and 3f in the Y-axis direction; and the magnetic flux path connection areas 4a, 4c, 4d, and 4f are respectively provided with two air gaps that pass through the metal soft magnetic material along the X-axis direction.

[0073] When the magnetic field to be measured is in the positive direction of the X-axis, the metallic soft magnetic material concentrates and amplifies the magnetic field to be measured and enters the magnetic field input area 1. It is then twisted to the positive and negative directions of the Y-axis on both sides in the magnetic flux direction conversion area 3a, forming two parallel magnetic flux paths. One of the magnetic paths passes through the magnetic flux path connection area 4a with an air gap along the positive direction of the Y-axis, generating a magnetic field component in the positive direction of the Y-axis in the air gap. It then passes through the magnetic flux direction conversion area 3b, the magnetic flux path connection area 4b, and the magnetic flux direction conversion area 3c in sequence, twisting the magnetic path from the positive direction of the Y-axis to the negative direction of the Y-axis, and then passes through the magnetic flux path connection area 4c with an air gap, generating a magnetic field component in the negative direction of the Y-axis in the air gap. Another magnetic circuit passes through the magnetic flux path connection area 4d with an air gap along the negative direction of the Y axis, and generates a magnetic field component in the negative direction of the Y axis in the air gap; the magnetic circuit then passes through the magnetic flux direction conversion area 3e, the magnetic flux path connection area 4e, and the magnetic flux direction conversion area 3f in sequence, twisting the magnetic circuit from the negative direction of the Y axis to the positive direction of the Y axis, and then passes through the magnetic flux path connection area 4f with an air gap, and generates a magnetic field component in the positive direction of the Y axis in the air gap; finally, the two magnetic circuits enter the magnetic flux direction conversion area 3d from the magnetic flux path connection area 4c along the negative direction of the Y axis and the magnetic flux path connection area 4f along the positive direction of the Y axis, and then twist back to the positive direction of the X axis, and then pass through the magnetic field output area 2. Taking the example of a magnetic field to be measured in the positive X-axis direction, one of the focused and amplified magnetic paths passes through magnetic flux path connection area 4a with an air gap along the positive Y-axis direction, and then passes through magnetic flux path connection area 4c with an air gap along the negative Y-axis direction. The other magnetic path passes through magnetic flux path connection area 4d with an air gap along the negative Y-axis direction, and then passes through magnetic flux path connection area 4f with an air gap along the positive Y-axis direction. At this time, the air gaps of magnetic flux path connection areas 4a and 4f generate magnetic field components in the positive Y-axis direction, while the air gaps of magnetic flux path connection areas 4c and 4d generate magnetic field components in the negative Y-axis direction. Since the sensitivity of magnetic induction units 5a, 5b, 5c, and 5d are all in the positive Y-axis direction, the resistance of magnetic induction units 5a and 5d decreases, while the resistance of magnetic induction units 5b and 5c increases. Since magnetic induction units 5a2, 5b2, 5c2, and 5d2, as magnetic shielding reference magnetic induction units, are located within the vertical projection of the metal soft magnetic material of magnetic flux conversion module 10, their resistance values ​​are considered approximately unchanged. Therefore, the magnetic sensing units 5a1, 5b1, 5c1, and 5d1 can be connected in series and parallel to form a push-pull half-bridge or full-bridge structure. Alternatively, the magnetic sensing units 5a1, 5b1, 5c1, and 5d1 can be combined with the magnetic sensing units 5a2, 5b2, 5c2, and 5d2, or with a reference resistor of a fixed resistance, to form a differential half-bridge or full-bridge structure to sense the magnetic field in the positive direction of the X-axis and generate a differential voltage signal. An open-loop signal conditioning circuit can be used to condition, amplify, temperature compensate, and perform linearity correction on the differential voltage signal to form the output electrical signal of the magnetic field sensor 01.

[0074] Alternatively, FIG9 shows a schematic diagram of another structure of a magnetic flux conversion module 10 and its magnetic field sensor 01. This is equivalent to symmetrically dividing the metal soft magnetic material structure of the magnetic flux conversion module 10 in FIG8 along the X-axis and performing translational exchange in the Y-axis direction. It can also be regarded as translating and connecting the magnetic flux conversion module 10 structures on the positive and negative sides of the Y-axis in FIG7 . The original magnetic field input area 1 and magnetic field output area 2 are symmetrically divided into magnetic field input areas 1a and 1b and magnetic field output areas 2a and 2b. The original magnetic flux direction conversion areas 3b and 3h are merged, the magnetic flux path connection areas 4b and 4e are merged, and the magnetic flux direction conversion areas 3c and 3g are merged. The measurement principle is basically the same as the structure shown in FIG7 , except that the soft magnetic materials on both sides of the Y-axis are close together and merged. Therefore, the measurement principle is not further described. Assuming that the magnetic field to be measured is in the positive direction of the X-axis, the magnetic circuit on the positive direction side of the Y-axis passes through the magnetic field input area 1a, the magnetic flux direction conversion area 3a, the magnetic flux path connection area 4a, the magnetic flux direction conversion area 3b, the magnetic flux path connection area 4b, the magnetic flux direction conversion area 3c, the magnetic flux path connection area 4c, the magnetic flux direction conversion area 3d, and the magnetic field output area 2a in sequence; the magnetic circuit on the negative direction side of the Y-axis passes through the magnetic field input area 1b, the magnetic flux direction conversion area 3e, the magnetic flux path connection area 4d, the magnetic flux direction conversion area 3b, the magnetic flux path connection area 4b, the magnetic flux direction conversion area 3c, the magnetic flux path connection area 4e, the magnetic flux direction conversion area 3f, and the magnetic field output area 2b in sequence; and the vertical projections of the magnetic induction units 5a, 5b, 5c, and 5d are respectively located at the air gap positions of the flux path connection areas 4a, 4c, 4d, and 4e.

[0075] By partially merging the separate metallic soft magnetic materials of the two parallel magnetic circuits, stability is increased and volume is reduced. Furthermore, the addition of a magnetic induction unit within the vertical projection of the metallic soft magnetic material of the magnetic flux conversion module 10, serving as a magnetic shielding reference magnetic induction unit, allows for the formation of a differential half-bridge or differential full-bridge structure to sense the magnetic field to be measured, helping to adjust and expand the measurement range of the magnetic field sensor 01. The magnetic shielding reference magnetic induction unit is adjacent to the magnetic induction unit at the air gap projection, both located near the air gap in the magnetic flux path connection area, helping to enhance consistency and reduce zero-point drift.

[0076] In one embodiment, the flux conversion module 10 also includes: a flux shielding soft magnetic path; the flux shielding soft magnetic path connects two flux path connection areas that are relatively arranged along the magnetic induction direction among at least four flux path connection areas; the flux shielding soft magnetic path is used to shield or separate the flux path connection areas with air gaps.

[0077] For example, as shown in Figure 10, the magnetic field sensor 01 includes a magnetic flux conversion module 10, a magnetic induction module 20, and a differential detection module 30. The magnetic field sensing direction of the magnetic field sensor 01 is the same as that of the magnetic flux conversion module 10, that is, the X-axis direction. The magnetic flux conversion module 10 is a single-plane, single-magnetic field sensing module and may include: a magnetic field input region 1, a magnetic field output region 2, six magnetic flux direction conversion regions 3a, 3b, 3c, 3d, 3e, 3f, six magnetic flux path connection regions 4a, 4b, 4c, 4d, 4e, 4f, and a magnetic flux shielding soft magnetic path 6. The magnetic induction module 20 may include: magnetic induction units 5a, 5b, 5c, 5d, 5e, 5f, and 5g. The sensitivity directions of all magnetic induction units 5 are in the positive direction of the Y-axis, wherein the vertical projections of the magnetic induction units 5a, 5b, 5c, and 5d are respectively located at the air gap positions of the magnetic flux path connection areas 4a, 4c, 4d, and 4f of the aforementioned magnetic flux conversion module 10, and the magnetic induction units 5e, 5f, and 5g are located within the vertical projection range of the metal soft magnetic material of the magnetic flux conversion module 10. As magnetic shielding reference magnetic induction units, they are respectively arranged at the positions of the magnetic flux direction conversion areas 3a, 3d and the magnetic flux shielding soft magnetic path 6. The magnetic induction units serving as magnetic shielding reference magnetic induction units are no longer distributed adjacent to the magnetic induction units at the air gap projection, but are selected at positions where the metal soft magnetic material has a larger coverage area. The magnetic field induction direction is the X-axis direction, and the metal soft magnetic material constituting the magnetic flux conversion module 10 is distributed in the XY plane. Taking the measured magnetic field as the positive direction of the X-axis as an example, in this case, the magnetic field input area 1 is located at the negative end of the X-axis, and the magnetic field output area 2 is located at the positive end of the X-axis; the magnetic flux direction conversion area 3a includes three ports pointing to the negative direction of the X-axis, the positive direction of the Y-axis, and the negative direction of the Y-axis, the magnetic flux direction conversion area 3b is a corner pointing to the positive direction of the X-axis and the negative direction of the Y-axis, the magnetic flux direction conversion area 3c is a corner pointing to the negative direction of the X-axis and the negative direction of the Y-axis, the magnetic flux direction conversion area 3d includes three ports pointing to the positive direction of the X-axis, the positive direction of the Y-axis, and the negative direction of the Y-axis, the magnetic flux direction conversion area 3e is a corner pointing to the positive direction of the X-axis and the positive direction of the Y-axis, and the magnetic flux direction conversion area 3f is a corner pointing to the negative direction of the X-axis and the positive direction of the Y-axis. The magnetic flux path connection area 4a is connected to the magnetic flux direction conversion areas 3a and 3b in the Y-axis direction, the magnetic flux path connection area 4b includes three ports pointing to the positive direction of the X-axis, the negative direction of the X-axis, and the negative direction of the Y-axis, the magnetic flux path connection area 4c is connected to the magnetic flux path connection areas 4b and 3d in the Y-axis direction, the magnetic flux path connection area 4d is connected to the magnetic flux direction conversion areas 3a and 3e in the Y-axis direction, the magnetic flux path connection area 4e includes three ports pointing to the positive direction of the X-axis, the negative direction of the X-axis, and the positive direction of the Y-axis, and the magnetic flux path connection area 4f is connected to the magnetic flux direction conversion areas 3d and 3f in the Y-axis direction; the magnetic flux shielding soft magnetic path 6 is connected to the magnetic flux path connection areas 4b and 4e in the Y-axis direction; and the magnetic flux path connection areas 4a, 4c, 4d, and 4f are respectively provided with two air gaps that pass through the metal soft magnetic material along the X-axis direction.

[0078] As shown in FIG11 , the magnetic flux path simulation diagram after the magnetic flux conversion module 10 in the embodiment of FIG10 is added with the magnetic field to be measured in the positive direction of the X axis can be seen: the magnetic field to be measured is gathered and amplified by the metal soft magnetic material to form a magnetic circuit, and is twisted on both sides to the positive direction of the Y axis and the negative direction of the Y axis to form two magnetic flux paths in parallel; then the two magnetic circuits are twisted in the Y axis direction and then twisted back to the positive direction of the X axis. It can be seen that the magnetic field to be measured can generate a significant magnetic field component in the positive direction of the Y axis at the air gap of the magnetic flux path connection area 4a, 4f, and a significant magnetic field component in the negative direction of the Y axis at the air gap of the magnetic flux path connection area 4c, 4d, thereby forming a differential magnetic field, and the magnetic flux path through the air gap is mirror-symmetrical about the X axis and is in a parallel relationship. When the magnetic field to be measured is in the positive direction of the Y axis, the magnetic flux shielding soft magnetic path 6 gathers and guides the magnetic field in the Y axis direction, achieving a shielding or magnetic separation effect on the magnetic flux path connection area with the air gap.

[0079] As shown in FIG12 , the magnetic flux path simulation diagram after the magnetic flux conversion module 10 in the embodiment of FIG10 is added to the magnetic field to be measured in the positive Y-axis direction shows that the majority of the magnetic field to be measured along the Y-axis direction forms a magnetic circuit along the magnetic flux shielding soft magnetic path 6 in the Y-axis direction, shielding or dividing the magnetic flux path connection area with the air gap. Similarly, taking the case where the magnetic field to be measured is in the positive X-axis direction as an example, the air gaps in the magnetic flux path connection areas 4a and 4f generate a magnetic field component in the positive Y-axis direction, while the air gaps in the magnetic flux path connection areas 4c and 4d generate a magnetic field component in the negative Y-axis direction. Since the sensitivity of the magnetic induction units 5a, 5b, 5c, and 5d are all in the positive Y-axis direction, the resistance of the magnetic induction units 5a and 5d decreases, while the resistance of the magnetic induction units 5b and 5c increases. Since the magnetic induction units 5e, 5f, and 5g, as magnetic shielding reference magnetic induction units, are located within the vertical projection of the metal soft magnetic material of the magnetic flux conversion module 10, their resistance values ​​are considered to be approximately unchanged. Therefore, the magnetic sensing units 5a, 5b, 5c, and 5d can be connected in series and parallel to form a push-pull half-bridge or full-bridge structure. Alternatively, the magnetic sensing units 5a, 5b, 5c, and 5d can be combined with the magnetic sensing units 5e, 5f, and 5g, or a reference resistor with a constant resistance, to form a differential half-bridge or full-bridge structure to sense the magnetic field in the positive direction of the X-axis and generate a differential voltage signal. An open-loop signal conditioning circuit can be used to condition, amplify, temperature-compensate, and perform linearity correction on the differential voltage signal to form the output electrical signal of the magnetic field sensor 01. The magnetic field sensor 01 may also include a substrate, lead pads, and a mechanical support housing. The manufacturing process employed is single-chip integration, and the magnetic sensing unit 5 employed is a magnetoresistive sensitive element, such as a tunnel magnetoresistor (TMR), whose sensitivity direction is parallel to the plane in which it resides.

[0080] By adding a flux-shielding soft magnetic path, the impact of the measured magnetic field on the operating range of the magnetic field sensor 01 is resolved, significantly increasing the operating range of the magnetic field sensor 01 under the measured magnetic field and improving the sensitivity consistency of the magnetic sensing unit. Furthermore, the magnetic sensing unit serving as the magnetic shielding reference unit is no longer located adjacent to the magnetic sensing unit at the air gap projection. Instead, it is located in a location with a larger coverage area of ​​the metal soft magnetic material, enhancing the magnetic shielding effect and making its resistance value more stable.

[0081] In one embodiment, the flux conversion module 10 includes: at least two magnetic field input areas and at least two magnetic field output areas; the flux shielding soft magnetic path connects two adjacent magnetic field input areas of the at least two magnetic field input areas, and the flux shielding soft magnetic path connects two adjacent magnetic field output areas of the at least two magnetic field output areas; the flux shielding soft magnetic path is used to shield or divide the magnetic flux path connection area with an air gap.

[0082] For example, as shown in FIG13 , based on the magnetic flux conversion module 10 of FIG9 , the structure can be formed by connecting the magnetic field input area 1a and 1b along the Y-axis direction at one end in the negative direction of the X-axis and one end in the positive direction of the X-axis using a metal soft magnetic material to form a magnetic flux shielding soft magnetic path 6a, and connecting the magnetic field output areas 2a and 2b to form a magnetic flux shielding soft magnetic path 6b; thereby, the magnetic field input area 1a and the magnetic field output area 2a include three ports pointing to the positive direction of the X-axis, the negative direction of the X-axis, and the negative direction of the Y-axis, and the magnetic field input area 1b and the magnetic field output area 2b include three ports pointing to the positive direction of the X-axis, the negative direction of the X-axis, and the positive direction of the Y-axis. As shown in FIG14 , from the magnetic flux path simulation diagram of the magnetic flux conversion module 10 of FIG13 after adding the magnetic field to be measured in the positive direction of the Y-axis, it can be seen that most of the magnetic field to be measured along the Y-axis direction forms a magnetic circuit along the magnetic flux shielding soft magnetic paths 6a and 6b in the Y-axis direction, shielding or dividing the magnetic flux path connection area with the air gap. In particular, for the magnetic field to be measured in the magnetic field sensing direction (the X-axis direction in this embodiment), the magnetic flux conversion module 10 is already able to convert the magnetic field in the magnetic field sensing direction into opposite magnetic field components in the positive and negative directions perpendicular to the magnetic field sensing direction, forming a differential magnetic field, which is then measured by a magnetic induction unit whose sensitivity direction is perpendicular to the magnetic field sensing direction. In an ideal situation, since all magnetic induction units are considered to be affected by the same magnetic field to be measured perpendicular to the magnetic field sensing direction, only the magnetic field to be measured in the magnetic field sensing direction will be reflected in the output electrical signal. However, in actual measurements, this detection method will reduce the working range of the magnetic field sensor 01. Specifically, take the tunnel magnetoresistance TMR as an example.

[0083] Figure 15 shows a schematic diagram of a voltage-magnetic field curve for a tunnel magnetoresistance (TMR). It can be seen that a linear range exists on both sides of the magnetic field zero point, which can be considered the normal operating range of a single magnetic induction unit. When operating within the linear range, the TMR sensitivity can be considered a constant value, with good sensitivity consistency. Assuming that the TMR sensitivity direction is the Y-axis, and a magnetic field of zero is applied to the Y-axis direction of the magnetic field sensor 01 in Figure 8, whose magnetic field sensing direction is the X-axis, the operating point of the magnetic induction unit is point A in Figure 15. When a magnetic field to be measured is introduced in the X-axis direction, the magnetic flux conversion module 10 converts the X-axis magnetic field into opposite magnetic field components in the positive and negative directions of the Y-axis, moving the operating points of the magnetic induction units to A1 and A2 in Figure 15, respectively. As long as A1 and A2 are within the linear range, all magnetic induction units can be considered to have the same sensitivity. Therefore, when the Y-axis magnetic field is zero, the magnetic field measurement range in the X-axis direction can span the entire linear range. When the Y-axis magnetic field is not zero, before the X-axis magnetic field is introduced, the magnetic induction unit's operating point moves from point A. To maintain operation within the linear range, the magnetic field measurement range in the X-axis direction is correspondingly reduced. In extreme cases, when the Y-axis magnetic field has already caused the operating point to move to the nonlinear range of points B or C, no matter how the X-axis magnetic field is reduced, the sensitivity of the magnetic induction unit is no longer a constant value, and the sensitivity loses consistency. To avoid the influence of the Y-axis magnetic field on the operating range of the magnetic field sensor 01 in the above-mentioned situation, the magnetic field sensor 01 with the magnetic flux conversion module 10 structure in Figures 10 and 13 is introduced with a flux shielding soft magnetic path 6. It can be seen that most of the magnetic field to be measured along the Y-axis direction forms a magnetic circuit along the flux shielding soft magnetic path 6 in the Y-axis direction, shielding or dividing the magnetic flux path connection area with the air gap, greatly reducing the influence of the Y-axis magnetic field to be measured on the magnetic induction unit. The Y-axis magnetic field detected by the magnetic induction unit almost all comes from the distortion and transformation of the X-axis magnetic field by the magnetic flux conversion module 10. Therefore, even if it is located under a larger Y-axis magnetic field to be measured, the working point of the magnetic induction unit can still be located near the zero point (point A), which significantly increases the working range of the magnetic field sensor 01 under the Y-axis magnetic field to be measured.

[0084] Alternatively, FIG16 shows a schematic diagram of a magnetic flux conversion module 10 and its magnetic field sensor 01 in another structure. Based on the magnetic flux conversion module 10 in FIG7 , this structure uses a metal soft magnetic material to connect the magnetic field input areas 1a and 1b along the Y-axis direction at one end in the negative direction of the X-axis and one end in the positive direction of the X-axis, forming a magnetic flux shielding soft magnetic path 6a, and connect the magnetic field output areas 2a and 2b to form a magnetic flux shielding soft magnetic path 6b. Thus, the magnetic field input area 1a and the magnetic field output area 2a include three ports pointing in the positive direction of the X-axis, the negative direction of the X-axis, and the negative direction of the Y-axis, and the magnetic field input area 1b and the magnetic field output area 2b include three ports pointing in the positive direction of the X-axis, the negative direction of the X-axis, and the positive direction of the Y-axis. The majority of the magnetic field to be measured along the Y-axis direction forms a magnetic circuit along the magnetic flux shielding soft magnetic paths 6a and 6b, shielding or dividing the magnetic flux path connection area with an air gap.

[0085] By adding a new magnetic flux shielding soft magnetic path and increasing the spacing between the soft magnetic materials where the magnetic induction module 20 is located, the isolation effect of the magnetic field to be measured can be further increased, the shielding or magnetic separation can be strengthened, and the influence of the magnetic field to be measured on the working range of the magnetic field sensor 01 can be solved. The working range of the magnetic field sensor 01 under the magnetic field to be measured is significantly increased, and the sensitivity consistency of the magnetic induction module 20 is improved.

[0086] In one embodiment, the magnetic flux conversion module 10 and the magnetic induction module 20 are provided on the same circuit chip using a chip integration process.

[0087] For example, the magnetic flux conversion module 10 and the magnetic induction module 20 can be located on the same circuit chip. The magnetic flux conversion module 10 is constructed of a metallic soft magnetic material with high magnetic permeability, deposited on a substrate within the circuit chip. The metallic soft magnetic material deposited on the substrate within the on-chip magnetic flux conversion module 10 forms a single or dual magnetic flux path through magnetic conductivity, generating magnetic field components in opposite directions at different air gap locations, forming a differential magnetic field, thereby forming a push-pull bridge structure.

[0088] This embodiment uses a single chip integration process to process the magnetic flux conversion module 10 and the magnetic induction unit on the same chip, thereby reducing costs.

[0089] In one embodiment, the soft magnetic materials of any two of the magnetic field input region, the magnetic field output region, the magnetic flux direction conversion region, and the magnetic flux path connection region are arranged on the same plane.

[0090] For example, the magnetic flux conversion module 10 and its magnetic field sensor 01 in the above embodiment are all single-plane single magnetic field sensing direction, that is, the soft magnetic materials of the magnetic field input area, magnetic field output area, magnetic flux direction conversion area, and magnetic flux path connection area are all arranged on the same plane. This has the advantage that only magnetic induction units with the same sensitivity direction need to be used, and a single chip integration manufacturing process can be used. At the same time, in actual production, it can meet the requirements if two of the soft magnetic materials of the magnetic field input area, magnetic field output area, magnetic flux direction conversion area, and magnetic flux path connection area are arranged on the same plane or on different planes. For a multi-axis magnetic field sensor 02 with multiple magnetic field sensing directions, any magnetic field sensing direction can adopt the structure of the above-mentioned single-plane single magnetic field sensing direction magnetic flux conversion module 10 and its magnetic field sensor 01, and then merge them. By arranging any two parts of the soft magnetic materials that constitute the magnetic flux path in the magnetic flux conversion module 10 on the same plane, the technical difficulty is reduced and it can meet the needs of more scenarios.

[0091] In one embodiment, the differential detection module 30 includes: an open-loop signal conditioning circuit; the open-loop signal conditioning circuit is electrically connected to the magnetic induction unit; the open-loop signal conditioning circuit is used to condition and amplify the differential voltage signal and / or perform temperature compensation and / or linearity correction.

[0092] Exemplarily, the magnetic induction unit can use a variety of sensitive elements depending on the placement position and direction. Specifically, when the sensitivity direction of the magnetic induction unit is perpendicular to the plane in which it is located, the substrate where the magnetic induction unit is located is perpendicular to the plane in which the magnetic flux conversion module 10 is located. For example, if the magnetic flux conversion module 10 located in the YZ plane selects a Hall element for measurement, then the substrate where each Hall element is located is parallel to the XZ plane. Then, the magnetic field sensor 01 is formed together with the magnetic induction module 20 through basic components such as the substrate, lead pads, and mechanical bracket housing, wherein an open-loop signal conditioning circuit is arranged on the substrate. The open-loop signal conditioning circuit is used to condition, amplify, temperature compensate, and correct the linearity of the differential voltage signal to form the output electrical signal of the current sensor. When the sensitivity direction of the magnetic induction unit is parallel to the plane in which it is located, the substrate where it is located is parallel to the plane in which the magnetic flux conversion module 10 is located. Because all magnetic sensing units can form a differential bridge or push-pull bridge using only sensitivity in the same direction, a magnetic sensing unit with sensitivity parallel to its own plane, such as a tunnel magnetoresistance (TMR), can be prepared in one go. This unit, combined with a magnetic flux conversion module 10 and an open-loop signal conditioning circuit, forms the magnetic field sensor 01. By employing an open-loop signal conditioning circuit for conditioning, amplification, temperature compensation, and linearity correction, open-loop detection is achieved, improving detection accuracy and achieving superior linearity.

[0093] In one embodiment, the differential detection module 30 includes: a closed-loop signal conditioning circuit and a magnetic field feedback coil; the closed-loop signal conditioning circuit is electrically connected to the magnetic induction unit; the closed-loop signal conditioning circuit, the magnetic field feedback coil and the magnetic induction unit constitute a closed-loop magnetic field feedback structure; the closed-loop signal conditioning circuit is used to condition and amplify the differential voltage signal; the magnetic field feedback coil is used to generate a feedback magnetic field according to the conditioned and amplified signal to achieve dynamic balance of the magnetic field, and sample the current in the magnetic field feedback coil to form an electrical signal to be measured.

[0094] For example, the output differential detection module 30 may utilize a closed-loop signal conditioning circuit and a magnetic field feedback coil. The closed-loop signal conditioning circuit, magnetic field feedback coil, and magnetic induction unit form a closed-loop magnetic field feedback structure. After the differential voltage signal is amplified by the closed-loop signal conditioning circuit, it is fed back through the magnetic field feedback coil to achieve dynamic magnetic field equilibrium. The current within the magnetic field feedback coil is sampled to form the output electrical signal to be measured by the magnetic field sensor 01. The magnetic field feedback coil can be wound externally to the magnetic flux conversion module 10 or integrated within the magnetic induction unit. The magnetic field sensor 01 may also include a substrate, lead pads, and a mechanical support housing. The fabrication process employed may be single-chip integration. The magnetic induction unit employed is a magnetoresistive (MR) sensitive element, such as a giant magnetoresistor (GMR), whose sensitivity direction is parallel to the plane in which it resides. By utilizing a closed-loop signal conditioning circuit and a magnetic field feedback coil for differential detection, closed-loop negative feedback is achieved, improving accuracy and achieving good linearity.

[0095] Please refer to Figure 17, which is a structural schematic diagram of a multi-axis magnetic field sensor 02 provided in an embodiment of the present application. The sensor includes: a plurality of magnetic field sensors 01 combined from the above-mentioned embodiments; the magnetic field sensing directions of the magnetic flux conversion modules 10 in the plurality of combined magnetic field sensors 01 are multiple; the magnetic flux conversion module 10 is used to perform differential detection on the corresponding magnetic field to be measured in any of the said magnetic field sensing directions.

[0096] Exemplarily, the above-mentioned magnetic flux conversion module 10 and its magnetic field sensor 01 are both single-plane and single-magnetic field sensing directions. For a multi-axis magnetic field sensor 02 having multiple magnetic field sensing directions, any magnetic field sensing direction can adopt the structure of the above-mentioned single-plane and single-magnetic field sensing direction magnetic flux conversion module 10 and its magnetic field sensor 01, and then be combined. Optionally, as shown in FIG17 , which is a structural schematic diagram of a dual-axis magnetic field sensor 01 with Y-axis and Z-axis dual magnetic field sensing directions, the magnetic flux conversion module 10 for the Y-axis magnetic field sensing direction adopts a structure similar to the magnetic flux conversion module 10 in FIG5 , and its magnetic induction module 20 can adopt a magnetic induction unit located in the XY plane and with a sensitivity direction located in the positive direction of the X-axis in the XY plane, forming a push-pull full-bridge structure. The magnetic flux conversion module 10 for the Z-axis magnetic field sensing direction adopts the structure of one half of the magnetic flux conversion module 10 for the Y-axis magnetic field sensing direction after being split along the X-axis. Its magnetic induction module 20 can adopt a magnetic induction unit located in the XY plane and with a sensitivity direction located in the positive direction of the X-axis in the XY plane, forming a push-pull half-bridge structure. Since the sensitivity direction of all magnetic induction units is the positive direction of the X-axis, a flux-shielding soft magnetic path 6 is added in the X-axis direction to shield or divide the magnetic field to be measured in the X-axis direction. The magnetic flux conversion module 10 and its magnetic field sensor 01 not only enable measurement of dual magnetic field induction directions on the Y and Z axes, but also enable push-pull bridge measurement of two magnetic field induction directions using only magnetic induction units with the same sensitivity direction. This allows for the one-time preparation of magnetic induction units, avoids the angular deviation and zero point offset problems caused by using different sensitivity directions in the prior art, and achieves good sensitivity consistency and high measurement accuracy.

[0097] Alternatively, as shown in Figures 18 and 19, two structural schematic diagrams and three-view drawings of two XYZ three-axis magnetic field sensing direction magnetic flux conversion modules 10 and their magnetic field sensors 01 are provided. The structure shown in Figure 18 is a schematic diagram of one of the magnetic flux conversion modules 10 and its magnetic field sensor 01 after all three axes adopt a structure similar to that of the magnetic flux conversion module 10 in Figure 7 and merge them; the structure shown in Figure 19 is a schematic diagram of one of the magnetic flux conversion modules 10 and its magnetic field sensor 01 after all three axes adopt a structure similar to that of the magnetic flux conversion module 10 in Figure 5 of Example 2 and merge them. For the above two structures, the magnetic induction units for any magnetic field sensing direction are located on different planes. Therefore, different types of magnetic induction modules 20 and bridge structures can be selected according to actual conditions to achieve measurement of the XYZ three axes separately.

[0098] By setting up a multi-axis sensor, not only can the magnetic induction modules 20 and measurement methods of the respective multi-axis directions be flexibly and independently selected, but the magnetic flux conversion module 10 in any direction also has the function of focusing, amplifying and guiding the magnetic path of the magnetic field to be measured in its own magnetic field induction direction, thereby being able to shield or divide the magnetic field of the magnetic induction modules 20 in other magnetic field induction directions, thereby increasing the working range of the magnetic field sensor 01 and improving flexibility.

[0099] The above description is merely an embodiment of the present application and is not intended to limit the scope of protection of the present application. For those skilled in the art, various modifications and variations of the present application are possible. Any modifications, equivalent substitutions, improvements, etc. made within the spirit and principles of the present application shall be included in the scope of protection of the present application.

Claims

1. A magnetic field sensor, characterized in that: The sensor comprises: a magnetic flux conversion module, a magnetic induction module and a differential detection module; the differential detection module is electrically connected to the magnetic induction module; The magnetic flux conversion module includes: a magnetic field input area, a magnetic field output area, a magnetic flux direction conversion area and a magnetic flux path connection area; the magnetic flux path connection area includes: at least two air gaps located at different positions; the magnetic induction module includes: at least two magnetic induction units; The magnetic flux path connection area connects the magnetic field input area, the magnetic field output area, and the magnetic flux direction conversion area through a magnetic circuit, and forms a magnetic flux path that enters from the magnetic field input area in the magnetic induction direction and outputs and connects the magnetic field output area; the at least two magnetic induction units are correspondingly arranged at the at least two air gap positions, and the sensitivity direction of the magnetic induction unit is perpendicular to the vertical projection direction of the air gap; Among them, the magnetic flux conversion module is used to conduct the magnetic field to be measured to the magnetic flux path along the magnetic induction direction, and generate a differential magnetic field component in the air gap of the magnetic flux path; the magnetic induction module is used to generate a differential voltage signal according to the differential magnetic field component; the differential detection module is used to process the differential voltage signal and output the electrical signal to be measured.

2. The sensor according to claim 1, characterized in that The magnetic flux conversion module comprises: a magnetic field input area, a magnetic field output area, at least three magnetic flux direction conversion areas and at least two magnetic flux path connection areas; The at least three magnetic flux direction conversion areas are located in the corner areas of the magnetic flux conversion module, and the at least two magnetic flux path connection areas connect two adjacent corner areas and form a single connected magnetic flux path with the magnetic field input area and the magnetic field output area in the magnetic induction direction; The at least two magnetic induction units are used to form a magnetic resistor of a push-pull half-bridge or push-pull full-bridge structure circuit, and sense the magnetic field to be measured in the magnetic induction direction to generate a differential voltage signal.

3. The sensor according to claim 1, characterized in that The magnetic flux conversion module comprises: a magnetic field input area, a magnetic field output area, at least four magnetic flux direction conversion areas and at least four magnetic flux path connection areas; The at least four magnetic flux direction conversion areas are located in the corner areas of the magnetic flux conversion module, and the at least four magnetic flux path connection areas connect two adjacent corner areas and form two connected magnetic flux paths with the magnetic field input area and the magnetic field output area in the magnetic induction direction; The at least two magnetic induction units are used to form a magnetic resistor of a push-pull half-bridge or push-pull full-bridge structure circuit, and sense the magnetic field to be measured in the magnetic induction direction to generate a differential voltage signal.

4. The sensor according to claim 3, characterized in that in, The magnetic induction module further comprises: a magnetic shielding reference magnetic induction unit; the magnetic shielding reference magnetic induction unit is located within the vertical projection range of the magnetic flux conversion module; The at least two magnetic induction units are used to form a magnetic resistance of a push-pull half-bridge or push-pull full-bridge structure circuit, and sense the magnetic field to be measured in the magnetic induction direction to generate a differential voltage signal; or The at least one magnetic induction unit and the magnetic shielding reference magnetic induction unit are used to form a magnetic resistance of a differential half-bridge or differential full-bridge structure circuit, and sense the magnetic field to be measured in the magnetic induction direction to generate a differential voltage signal.

5. The sensor according to claim 3, characterized in that in, The magnetic flux conversion module further includes: a magnetic flux shielding soft magnetic path; The flux-shielding soft magnetic path connects two of the at least four flux-path connection areas that are arranged opposite to each other along the magnetic induction direction; the flux-shielding soft magnetic path is used to shield or separate the flux-path connection areas with air gaps.

6. The sensor according to claim 5, characterized in that in, The magnetic flux conversion module comprises: at least two magnetic field input areas and at least two magnetic field output areas; The flux-shielding soft magnetic path connects two adjacent magnetic field input areas among the at least two magnetic field input areas, and the flux-shielding soft magnetic path connects two adjacent magnetic field output areas among the at least two magnetic field output areas; the flux-shielding soft magnetic path is used to shield or divide the magnetic flux path connection area with an air gap.

7. The sensor according to any one of claims 1 to 6, characterized in that: The magnetic flux conversion module and the magnetic induction module are arranged on the same circuit chip by using chip integration technology.

8. The sensor according to any one of claims 1 to 6, characterized in that: The soft magnetic materials of any two of the magnetic field input area, the magnetic field output area, the magnetic flux direction conversion area, and the magnetic flux path connection area are arranged on the same plane.

9. The sensor according to any one of claims 1 to 6, characterized in that: The differential detection module comprises: an open-loop signal conditioning circuit; the open-loop signal conditioning circuit is electrically connected to the magnetic induction unit; the open-loop signal conditioning circuit is used to condition and amplify the differential voltage signal and / or perform temperature compensation and / or linearity correction.

10. The sensor according to any one of claims 1 to 6, characterized in that: The differential detection module includes: a closed-loop signal conditioning circuit and a magnetic field feedback coil; The closed-loop signal conditioning circuit is electrically connected to the magnetic induction unit; the closed-loop signal conditioning circuit, the magnetic field feedback coil and the magnetic induction unit form a closed-loop magnetic field feedback structure; The closed-loop signal conditioning circuit is used to condition and amplify the differential voltage signal; the magnetic field feedback coil is used to generate a feedback magnetic field according to the conditioned and amplified signal to achieve a dynamic balance of the magnetic field, and to sample the current in the magnetic field feedback coil to form the electrical signal to be measured.

11. A multi-axis magnetic field sensor, characterized in that: The sensor comprises: a plurality of magnetic field sensors according to any one of claims 1 to 10 in combination; The magnetic field sensing directions of the magnetic flux conversion module in the magnetic field sensor according to any one of claims 1 to 10 of the plurality of combinations are multiple; The magnetic flux conversion module is used to perform differential detection on the corresponding magnetic field to be measured in any of the magnetic field induction directions.

Images