Multi-axis magnetic field sensor and multi-axis magnetic field sensor chip

Abstract

The present application provides a multi-axis magnetic field sensor and a multi-axis magnetic field sensor chip, the multi-axis magnetic field sensor comprising: a first magnetic conductor arranged on a first substrate; a second magnetic conductor arranged on a passivation layer or a second substrate; and a first air gap is formed based on the first magnetic conductor and the second magnetic conductor; a third magnetic conductor having a second air gap and arranged on the substrate or the passivation layer; a fourth magnetic conductor having a third air gap and arranged on the substrate or the passivation layer; and at least three magnetic induction units respectively located in corresponding air gap regions; wherein the magnetic induction units in the passivation layer have the same magnetic induction sensitivity direction. The magnetic induction units in the same passivation layer of the multi-axis magnetic field sensor provided by the present application have the same magnetic induction sensitivity direction, which can realize the single-chip preparation of the multi-axis magnetic field sensor, and the prepared multi-axis magnetic field sensor has better stability and higher precision.

Description

Technical Field

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

[0002] Magnetic sensors are devices that detect corresponding physical quantities by converting changes in the magnetic properties of sensitive components caused by external factors such as magnetic fields, currents, stress strains, temperature, and light into electrical signals. They are widely used in modern industry and electronic products to measure physical parameters such as current, position, and direction by sensing changes in magnetic field strength.

[0003] Currently, most common three-axis magnetic field sensors use a multi-chip packaging method, for example, a horizontal direction (XY axis) magnetic field sensor and a vertical direction (Z axis) magnetic field sensor are packaged together. Existing three-axis magnetic field sensors have poor accuracy, are difficult to achieve single-chip integrated manufacturing, and have poor vertical magnetic field collection effect. Summary of the invention

[0004] In view of this, the purpose of the embodiments of the present application is to provide a multi-axis magnetic field sensor and a multi-axis magnetic field sensor chip to solve the technical problems that the existing three-axis magnetic field sensors have poor accuracy and are difficult to achieve single-chip integrated manufacturing.

[0005] In a first aspect, an embodiment of the present application provides a multi-axis magnetic field sensor, the multi-axis magnetic field sensor comprising: at least one first magnetic conductor disposed in a third direction on a first substrate;

[0006] At least one second magnetic conductor in the third direction is arranged on the passivation layer or the second substrate; the difference in number between the first magnetic conductor and the second magnetic conductor is less than 2, and the projections of the first magnetic conductor and the second magnetic conductor on the substrate do not have an overlapping area or the overlapping area is less than half of the magnetic area of ​​the magnetic conductor; wherein the substrate is the first substrate or the second substrate, and the magnetic area of ​​the magnetic conductor is the magnetic area of ​​the first magnetic conductor or the magnetic area of ​​the second magnetic conductor;

[0007] A first air gap, wherein the first air gap is formed based on the first magnetic conductor and the second magnetic conductor;

[0008] A third magnetic conductor in a second direction is disposed on the substrate or the passivation layer, and the third magnetic conductor has a second air gap;

[0009] A fourth magnetic conductor in a first direction disposed on the substrate or the passivation layer, the fourth magnetic conductor having a third air gap; wherein the first direction, the second direction and the third direction are perpendicular to each other;

[0010] At least three magnetic induction units, wherein the magnetic induction units are respectively located in corresponding air gap areas; wherein the air gap areas include the air gap areas of the first air gap, the second air gap and the third air gap, and the sensors respectively form magnetic signal output circuits for measuring different magnetic induction intensity directions based on the magnetic induction units; wherein the passivation layer is a passivation protection layer around the magnetic induction units, and the magnetic induction units in the same passivation layer have the same magnetic induction sensitivity direction.

[0011] In the above implementation process, the multi-axis magnetic field sensor includes: a first magnetic conductor in a third direction, a second magnetic conductor in a third direction, a first air gap formed based on the first magnetic conductor and the second magnetic conductor, a third magnetic conductor with a second air gap, a fourth magnetic conductor with a third air gap, and at least three magnetic induction units, and a magnetic signal output circuit for measuring different directions of magnetic induction intensity is formed based on the magnetic induction units arranged in the corresponding air gap areas. Since the magnetic induction units in the same passivation layer have the same magnetic induction sensitivity direction, the single-chip preparation of the multi-axis magnetic field sensor can be realized, and the prepared multi-axis magnetic field sensor has better stability and higher accuracy. The multi-axis magnetic field sensor provided by the present application can solve the "technical problem that the existing three-axis magnetic field sensor has poor accuracy and is difficult to realize single-chip integrated manufacturing".

[0012] In addition, the present application adopts a double-layer spaced-spaced soft magnetic array vertical detection structure (i.e., the magnetic field measurement area in the vertical direction formed by the first magnetic conductor and the second magnetic conductor) to solve the problems of uneven magnetic field distribution in the measurement direction, serious sensitivity loss, low precision and high noise in the long soft magnetic sheets arranged in a single-layer array, enhances the magnetic field concentration effect and magnetic field uniformity in the vertical direction, has higher magnetic field conversion efficiency, improves sensitivity, improves the overall accuracy, sensitivity and stability of the three-axis sensor, and reduces noise.

[0013] Optionally, in an embodiment of the present application, the third magnetic conductor includes: a third magnetic field input zone in the second direction located at both ends of the third magnetic conductor and a third magnetic field conversion zone located between the two ends of the third magnetic conductor; the third magnetic field conversion zone includes a third magnetic field conversion magnetic circuit in the first direction; wherein the third magnetic field conversion magnetic circuit has the second air gap.

[0014] In the above implementation process, the magnetic field to be measured in the second direction input by the third magnetic field input area is converted based on the third magnetic field conversion area, and the third magnetic field conversion magnetic circuit in the first direction forms a magnetic field component to be measured in the first direction, and then a first magnetic signal output circuit for measuring the magnetic induction intensity in the first direction is formed through the second magnetic induction unit located in the second air gap area.

[0015] Optionally, in an embodiment of the present application, the second air gap includes a first conversion air gap and a second conversion air gap; the third magnetic field conversion magnetic circuit includes adjacent first conversion magnetic circuit and second conversion magnetic circuit; the first conversion magnetic circuit has the first conversion air gap, and the second conversion magnetic circuit has the second conversion air gap; the sensor forms a second magnetic signal output circuit for detecting the magnetic induction intensity in the second direction based on the first conversion magnetic induction unit and the second conversion magnetic induction unit; wherein the first conversion magnetic induction unit and the second conversion magnetic induction unit are respectively located in the air gap areas of the first conversion air gap and the second conversion air gap.

[0016] In the above implementation process, since the first conversion magnetic circuit and the second conversion magnetic circuit are adjacent conversion magnetic circuits in the first direction, after the measured magnetic field enters from the "third magnetic field input area in the second direction", magnetic field components with opposite directions will be formed at the first conversion air gap and the second conversion air gap, and the resistance values ​​of the first conversion magnetic induction unit and the second conversion magnetic induction unit will change in the opposite direction, thereby more sensitively reflecting the changes in the measured magnetic field in the second direction, thereby improving the detection sensitivity of the multi-axis magnetic field sensor to the magnetic induction intensity in the second direction.

[0017] Optionally, in an embodiment of the present application, the fourth magnetic conductor includes: a fourth magnetic field input zone in the first direction located at both ends of the fourth magnetic conductor and a fourth magnetic field conversion zone located between the two ends of the fourth magnetic conductor; the fourth magnetic field conversion zone includes a fourth magnetic field conversion magnetic circuit in the second direction; wherein the fourth magnetic field conversion magnetic circuit has the third air gap.

[0018] In the above implementation process, the magnetic field to be measured in the first direction input by the fourth magnetic field input area is converted based on the fourth magnetic field conversion area, and the fourth magnetic field conversion magnetic circuit in the second direction forms a magnetic field component to be measured in the second direction, and then a second magnetic signal output circuit for measuring the magnetic induction intensity in the second direction is formed through the third magnetic induction unit located in the third air gap area.

[0019] Optionally, in an embodiment of the present application, the third air gap includes a third conversion air gap and a fourth conversion air gap; the fourth magnetic field conversion magnetic circuit includes adjacent third conversion magnetic circuit and fourth conversion magnetic circuit; the third conversion magnetic circuit has the third conversion air gap, and the fourth conversion magnetic circuit has the fourth conversion air gap; the sensor forms a first magnetic signal output circuit for detecting the magnetic induction intensity in the first direction based on the third conversion magnetic induction unit and the fourth conversion magnetic induction unit; wherein the third conversion magnetic induction unit and the fourth conversion magnetic induction unit are respectively located in the air gap areas of the third conversion air gap and the fourth conversion air gap.

[0020] In the above implementation process, since the third conversion magnetic circuit and the fourth conversion magnetic circuit are adjacent conversion magnetic circuits in the second direction, after the measured magnetic field enters from the "third magnetic field input area in the first direction", magnetic field components with opposite directions will be formed at the third conversion air gap and the fourth conversion air gap, and the resistance values ​​of the third conversion magnetic induction unit and the fourth conversion magnetic induction unit will change in the opposite direction, thereby more sensitively reflecting the changes in the measured magnetic field in the first direction, thereby improving the detection sensitivity of the multi-axis magnetic field sensor to the magnetic induction intensity in the first direction.

[0021] Optionally, in an embodiment of the present application, the sensor further includes: a first magnetically shielded magnetic induction unit; the projection of the first magnetically shielded magnetic induction unit on the substrate is located within the magnetic conductive region of the third magnetic conductive body; the sensor forms a second magnetic signal output circuit for detecting the magnetic induction intensity in the second direction based on the first magnetic induction unit located in the second air gap region and the first magnetically shielded magnetic induction unit.

[0022] In the above implementation process, since the projection of the first magnetic shielding induction unit on the substrate is located in the magnetic conductive area of ​​the third magnetic conductive body, the magnetic field signal detected by the first magnetic shielding induction unit is weakened by the third magnetic conductive body. Therefore, compared with the resistance change of the first magnetic induction unit, the resistance of the first magnetic shielding induction unit is almost unchanged. The second magnetic signal output circuit for detecting the magnetic induction intensity in the second direction formed by the first magnetic induction unit and the first magnetic shielding magnetic induction unit has a low sensitivity and can have a larger magnetic field intensity detection range, thereby realizing a large-range low-sensitivity measurement of the magnetic induction intensity in the second direction.

[0023] Optionally, in an embodiment of the present application, the sensor further includes: a second magnetically shielded magnetic induction unit; the projection of the second magnetically shielded magnetic induction unit on the substrate is located within the magnetic conductive area of ​​the fourth magnetic conductive body; the sensor is based on the second magnetic induction unit located in the third air gap area and the second magnetically shielded magnetic induction unit to form a first magnetic signal output circuit for detecting the magnetic induction intensity in the first direction.

[0024] In the above implementation process, since the projection of the second magnetic shielding induction unit on the substrate is located in the magnetic conductive area of ​​the fourth magnetic conductive body, the magnetic field signal detected by the second magnetic shielding induction unit is weakened by the fourth magnetic conductive body. Therefore, compared with the resistance change of the second magnetic induction unit, the resistance of the second magnetic shielding induction unit is almost unchanged. The first magnetic signal output circuit for detecting the magnetic induction intensity in the first direction formed by the second magnetic induction unit and the second magnetic shielding magnetic induction unit has a low sensitivity and can have a larger magnetic field intensity detection range, thereby realizing a large-range low-sensitivity measurement of the magnetic induction intensity in the first direction.

[0025] Optionally, in an embodiment of the present application, the sensor also includes: an external magnetic field magnetic induction unit; the distances between the external magnetic field magnetic induction unit and the first magnetic conductor, the second magnetic conductor, the third magnetic conductor and the fourth magnetic conductor are all greater than a preset distance; the sensor forms a magnetic signal output circuit for measuring different magnetic induction intensity directions based on the magnetic induction unit and the external magnetic field magnetic induction unit.

[0026] In the above implementation process, since the distance between the external magnetic field magnetic induction unit and the first magnetic conductor, the second magnetic conductor, the third magnetic conductor and the fourth magnetic conductor is relatively far (greater than the preset distance), the external magnetic field magnetic induction unit will be directly affected by the external magnetic field (compared with the magnetic field inside the first magnetic conductor, the second magnetic conductor, the third magnetic conductor and the fourth magnetic conductor, the external magnetic field refers to the external magnetic field to be measured). Therefore, the sensitivity of the magnetic signal output circuit for measuring different magnetic induction intensity directions formed by the external magnetic field magnetic induction unit and the corresponding magnetic induction unit is low, and a larger magnetic field intensity detection range can be provided, so as to realize a large range of low-sensitivity measurement of magnetic induction intensity in different directions.

[0027] Optionally, in an embodiment of the present application, the grooves in the substrate are etched using a reverse DRIE deep reactive ion etching process, and after a metal soft magnetic material is deposited in the grooves, polishing is performed using a CMP chemical mechanical polishing process.

[0028] In the above implementation process, the reverse DRIE deep reactive ion etching process is used to form grooves, which can enhance the magnetic field gathering effect and improve the sensitivity, and solve the technical problems in the prior art that the magnetic flux gathering structure has low magnetic field conversion efficiency in the measurement direction, sensitivity loss, and high noise.

[0029] Optionally, in an embodiment of the present application, the sensor further includes: a resistor (preferably a fixed-value resistor); the sensor forms a magnetic signal output circuit for measuring different directions of magnetic induction intensities based on the magnetic induction unit and the resistor.

[0030] In the above implementation process, a magnetic signal output circuit for measuring magnetic induction intensities in different directions can be formed by resistors and corresponding magnetic induction units, and the structure is simpler, which can reduce the difficulty of actual process packaging. In addition, the magnetic signal output circuit formed by resistors and corresponding magnetic induction units has low sensitivity, and can have a larger magnetic field strength detection range, realizing a large range of low-sensitivity measurement of magnetic induction intensities in different directions.

[0031] Optionally, in an embodiment of the present application, the sensor further includes: the sensor further includes: an open-loop signal conditioning circuit; the open-loop signal conditioning circuit is electrically connected to the magnetic signal output circuit; the sensor conditions and amplifies, temperature compensates and / or linearizes the electrical signal output by the magnetic signal output circuit based on the open-loop signal conditioning circuit to obtain a first conditioned signal; and outputs the first conditioned signal; or, the sensor further includes: a closed-loop signal conditioning circuit and a magnetic field feedback coil; the sensor forms a closed-loop magnetic field feedback structure based on the closed-loop signal conditioning circuit, the magnetic field feedback coil and the magnetic induction unit; the sensor conditions and amplifies, temperature compensates and / or linearizes the electrical signal output by the magnetic signal output circuit based on the closed-loop magnetic field feedback structure, and generates a feedback magnetic field to achieve a dynamic balance of the magnetic field, to obtain a second conditioned signal; and outputs the second conditioned signal; wherein, the second conditioned signal represents the feedback current of the magnetic field feedback coil when the magnetic field dynamic balance state is reached.

[0032] In the above-mentioned implementation process, after the electrical signal output by the magnetic signal output circuit is conditioned, amplified, temperature compensated and / or linearly corrected by the signal conditioning circuit (open-loop signal conditioning circuit / closed-loop signal conditioning circuit and magnetic field feedback coil), a conditioned standard signal (first conditioned signal / second conditioned signal) can be obtained to ensure that the conditioned standard signal can be more accurately recognized by the corresponding magnetic detection system, thereby improving the accuracy of the magnetic field detection results obtained based on the multi-axis magnetic field sensor.

[0033] In a second aspect, an embodiment of the present application provides a multi-axis magnetic field sensor chip, which is packaged by any of the multi-axis magnetic field sensors described in the first aspect through WLP wafer-level packaging and TSV through silicon via technology.

[0034] A multi-axis magnetic field sensor provided by the present application is adopted, and a magnetic signal output circuit for measuring different magnetic induction intensity directions is formed by a magnetic induction unit arranged in the corresponding air gap area. Since the magnetic induction units in the same passivation layer have the same magnetic induction sensitivity direction, the multi-axis magnetic field sensor provided by the present application can be prepared on a single chip, and the prepared multi-axis magnetic field sensor has better stability and higher accuracy, which solves the "technical problem that the existing three-axis magnetic field sensor has poor accuracy and is difficult to achieve single-chip integrated manufacturing". BRIEF DESCRIPTION OF THE DRAWINGS

[0035] In order to more clearly illustrate the technical solutions of the embodiments of the present application, the drawings required for use in the embodiments of the present application will be briefly introduced below. 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 related drawings can be obtained based on these drawings without paying creative work.

[0036] Figure 1 A schematic diagram of the structure of a first multi-axis magnetic field sensor provided in an embodiment of the present application;

[0037] Figure 2 A schematic diagram of the structure of a second multi-axis magnetic field sensor provided in an embodiment of the present application;

[0038] Figure 3 A first magnetic flux path simulation schematic diagram provided in an embodiment of the present application;

[0039] Figure 4 A second magnetic flux path simulation schematic diagram provided in an embodiment of the present application;

[0040] Figure 5 A schematic diagram of the structure of a third multi-axis magnetic field sensor provided in an embodiment of the present application;

[0041] Figure 6 A schematic diagram of the structure of a fourth multi-axis magnetic field sensor provided in an embodiment of the present application;

[0042] Figure 7 A schematic diagram of the structure of a fifth multi-axis magnetic field sensor provided in an embodiment of the present application;

[0043] Figure 8 A third magnetic flux path simulation schematic diagram provided in an embodiment of the present application. DETAILED DESCRIPTION

[0044] The following embodiments of the technical solution of the present application will be described in detail in conjunction with the accompanying drawings. The following embodiments are only used to more clearly illustrate the technical solution of the present application, and are therefore only used as examples, and cannot be used to limit the scope of protection of the present application.

[0045] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by technicians in the technical field to which this application belongs; the terms used herein are only for the purpose of describing specific embodiments and are not intended to limit this application.

[0046] In the description of the embodiments of the present application, the technical terms "first", "second", etc. are only used to distinguish different objects, and cannot be understood as indicating or implying relative importance or implicitly indicating the number, specific order or primary and secondary relationship of the indicated technical features. In the description of the embodiments of the present application, the meaning of "multiple" is two or more, unless otherwise clearly and specifically defined.

[0047] Please refer to Figure 1 , Figure 1 This is a schematic diagram of the structure of the first multi-axis magnetic field sensor provided in the embodiment of the present application. Specifically, Figure 1 The upper part of FIG. 1 is a schematic diagram of the projection structure of the multi-axis magnetic field sensor on the plane (XY plane) where the first substrate 1a is located. Figure 1 The lower part of the figure shows a schematic diagram of the projection structure of the multi-axis magnetic field sensor on the XZ plane (the plane where the first substrate is located is the XY plane). Figure 2 , Figure 2 This is a schematic diagram of the structure of the second multi-axis magnetic field sensor provided in the embodiment of the present application. Specifically, Figure 2 The upper part of the figure shows a schematic diagram of the projection structure of "the component between the passivation layer 1c and the second substrate 1b" in the multi-axis magnetic field sensor on the plane (XY plane) where the second substrate 1b is located. Figure 2 The middle part of the figure shows a schematic diagram of the projection structure of "the passivation layer 1c and the components between the passivation layer 1c and the first substrate 1a" in the multi-axis magnetic field sensor on the plane (XY plane) where the first substrate 1a is located. Figure 2 The lower part of the figure shows a schematic diagram of the projection structure of the multi-axis magnetic field sensor on the XZ plane (the plane where the first substrate 1a or the second substrate 1b is located is the XY plane). The multi-axis magnetic field sensor includes:

[0048] At least one first magnetic conductor 2z1 disposed in a third direction on the first substrate 1a;

[0049] At least one second magnetic conductor 2z3 in the third direction is arranged on the passivation layer 1c or the second substrate 1b; the difference in number between the first magnetic conductor 2z1 and the second magnetic conductor 2z3 is less than 2, and the projections of the first magnetic conductor 2z1 and the second magnetic conductor 2z3 on the substrate do not have an overlapping area or the overlapping area is less than half of the magnetic area of ​​the magnetic conductor; wherein the substrate is the first substrate 1a or the second substrate 1b, and the magnetic area of ​​the magnetic conductor is the magnetic area of ​​the first magnetic conductor 2z1 or the magnetic area of ​​the second magnetic conductor 2z3;

[0050] A first air gap, wherein the first air gap is formed based on the first magnetic conductor 2z1 and the second magnetic conductor 2z3;

[0051] A third magnetic conductor 2x1 (may include 2x1a and 2x1b) in a second direction disposed on the substrate (the first substrate 1a or the second substrate 1b) or the passivation layer 1c, wherein the third magnetic conductor 2x1 has a second air gap;

[0052] A fourth magnetic conductor 2y1 (which may include 2y1a and 2y1b) in a first direction is disposed on a substrate (a first substrate 1a or a second substrate 1b) or a passivation layer 1c, and the fourth magnetic conductor 2y1 has a third air gap; wherein the first direction, the second direction and the third direction are perpendicular to each other;

[0053] At least three magnetic induction units (at least one of 2x2a, 2x2c, at least one of 2y2a and 2y2b, and at least one of 2z2a, 2z2b, 2x2c, and 2z2d), the magnetic induction units are respectively located in corresponding air gap regions; wherein the air gap regions include the air gap regions of the first air gap, the second air gap, and the third air gap, and the sensor forms a magnetic signal output circuit for measuring different directions of magnetic induction intensity based on the magnetic induction units; wherein the passivation layer 1c is a passivation protection layer around the magnetic induction unit, and the magnetic induction units in the same passivation layer have the same magnetic induction sensitivity direction. The "magnetic induction sensitivity direction of the magnetic induction unit" located in the air gap region of the first air gap is consistent with the main magnetic field direction of the air gap region of the first air gap. The "magnetic induction sensitivity direction of the magnetic induction unit" located in the air gap region of the second air gap is consistent with the main magnetic field direction of the air gap region of the second air gap. The "magnetic induction sensitivity direction of the magnetic induction unit" located in the air gap region of the third air gap is consistent with the main magnetic field direction of the air gap region of the third air gap.

[0054] Among them, the direction of the magnetic conductor (the first magnetic conductor, the second magnetic conductor, the third magnetic conductor, and the fourth magnetic conductor) is consistent with the direction of the magnetic induction intensity measured by the "magnetic signal output circuit implemented based on the magnetic conductor". The above-mentioned substrate (the first substrate 1a or the second substrate 1b) refers to the wafer substrate. The first magnetic conductor 2z1, the second magnetic conductor 2z3, the third magnetic conductor 2x1 and the fourth magnetic conductor 2y1 can be magnetic conductive areas formed on the substrate by soft magnetic materials, such as silicon steel sheets, low carbon steel or iron-silicon alloys. The first air gap, the second air gap and the third air gap refer to the gaps between soft magnetic materials; the first air gap, the second air gap and the third air gap can be gaps formed by air or other non-magnetic conductive materials. The number of the first air gaps can be one or more, and the number of the second air gaps can also be one or more, and the present application does not make specific restrictions on this. Specifically, if the number of first magnetic conductors 2z1 is 1 and the number of second magnetic conductors 2z3 is 1, a first air gap can be formed based on the first magnetic conductors 2z1 and the second magnetic conductors 2z3; if the number of first magnetic conductors 2z1 is 1 and the number of second magnetic conductors 2z3 is 2, or the number of first magnetic conductors 2z1 is 2 and the number of second magnetic conductors 2z3 is 1, two first air gaps can be formed based on the first magnetic conductors 2z1 and the second magnetic conductors 2z3. The magnetic induction unit can be a magnetoresistive film (MR), specifically, a giant magnetoresistance (GMR), a tunnel magnetoresistance (TMR), an anisotropic magnetoresistance (AMR), etc. The first magnetic conductor 2z1 can be specifically arranged in the groove of the first substrate 1a, or on the surface of the first substrate 1a; the second magnetic conductor 2z3 can be arranged on the surface of the passivation layer, or on the surface of the second substrate 1b or in the groove of the second substrate 1b; the third magnetic conductor 2x1 can be arranged on the surface or in the groove of the first substrate 1a, or on the surface or in the groove of the second substrate 1b, or on the surface of the passivation layer; the fourth magnetic conductor 2y1 can be arranged on the surface or in the groove of the first substrate 1a, or on the surface or in the groove of the second substrate 1b, or on the surface of the passivation layer.

[0055] Among them, a first magnetic signal output circuit for detecting the magnetic induction intensity in the first direction can be formed based on the second magnetic induction unit (2y2a or 2y2b) and the resistor; the first magnetic signal output circuit can also be formed based on the second magnetic induction unit (2y2a or 2y2b) and the external magnetic field magnetic induction unit 2A, and the first magnetic signal output circuit can also be formed based on the second magnetic induction units 2y2a and 2y2b. A second magnetic signal output circuit for detecting the magnetic induction intensity in the second direction can be formed based on the first magnetic induction unit (2x2a or 2x2c) and the resistor; the second magnetic signal output circuit can also be formed based on the first magnetic induction unit (2x2a or 2x2c) and the external magnetic field magnetic induction unit 2A, and the first magnetic signal output circuit can also be formed based on the first magnetic induction units 2x2a and 2x2c. A third magnetic signal output circuit for detecting the magnetic induction intensity in a third direction can be formed based on a third magnetic induction unit (any one of 2z2a, 2z2b, 2x2c or 2z2d) and a resistor, wherein the third direction refers to a direction perpendicular to the plane where the substrate (the first substrate 1a or the second substrate 1b) is located; the third magnetic signal output circuit can also be formed based on a third magnetic induction unit (any one of 2z2a, 2z2b, 2x2c or 2z2d) and an external magnetic field magnetic induction unit 2A, and the third magnetic signal output circuit can also be formed based on the third magnetic induction unit "2z2a and 2z2b", "2z2a and 2z2d", "2z2b and 2z2c" or "2z2c and 2z2d". The first magnetic signal output circuit, the second magnetic signal output circuit and the third magnetic signal output circuit can be differential half-bridge or differential full-bridge output circuits.

[0056] by Figure 1 The plane where the first substrate 1a is located is the XY plane, the first direction is the Y axis direction, the second direction is the X axis direction, and the third direction is the Z axis. For example, the left side is the magnetic field measurement area 2x in the X axis direction, the middle is the magnetic field measurement area 2y in the Y axis direction, and the right side is the magnetic field measurement area 2z in the Z axis direction. The magnetic field measurement area 2z includes a first magnetic conductor 2z1 and a second magnetic conductor 2z3 made of a high magnetic permeability metal soft magnetic material. Figure 1As shown, in this embodiment, the multi-axis magnetic field sensor includes three strips of metal soft magnetic materials (first magnetic conductors 2z1) for detecting the magnetic induction intensity in the Z-axis direction formed on the first substrate 1a by deposition and semiconductor micromachining, and multiple first magnetic conductors 2z1 are spaced apart in the X-axis direction. After the surface of the first magnetic conductor 2z1 is polished by CMP chemical mechanical polishing process and a passivation layer is deposited, an MR magnetoresistive film is deposited on the surface of the passivation layer and a third magnetic induction unit (2z2a, 2z2b, 2x2c and 2z2d) is formed by semiconductor graphic micromachining. After the passivation layer is deposited again on the third magnetic induction unit (2z2a, 2z2b, 2x2c and 2z2d) to protect the magnetoresistive film, two strips of metal soft magnetic materials (second magnetic conductors 2z3) for detecting the magnetic induction intensity in the Z-axis direction are formed on the passivation layer by deposition and semiconductor micromachining, and multiple second magnetic conductors 2z3 are spaced apart in the X-axis direction. The MR magnetoresistive film used by the third magnetic sensing unit may be a giant magnetoresistance GMR. Figure 1 The figure shows that the projections of the first magnetic conductor 2z1 and the second magnetic conductor 2z3 on the first substrate do not overlap. The vertical projections of the third magnetic induction units 2z2a, 2z2b, 2z2c, and 2z2d in the Z-axis direction (i.e., the projections of the third magnetic induction units 2z2a, 2z2b, 2z2c, and 2z2d on the first substrate 1a) are located in the interval distribution area of ​​the metal soft magnetic materials of the first magnetic conductor 2z1 and the second magnetic conductor 2z3.

[0057] Specifically, the direction of the external magnetic field is the positive direction of the Z axis, and the directions of the magnetic induction sensitivity of the third magnetic induction units 2z2a, 2z2b, 2z2c, and 2z2d are all in the positive direction of the X axis. At this time, the direction of the converted X-axis magnetic field component at the position of the third magnetic induction units 2z2a and 2z2c is the positive direction of the X axis, and the direction at the position of the third magnetic induction units 2z2b and 2z2d is the negative direction of the X axis. Since the directions of the magnetic induction sensitivity of the third magnetic induction units 2z2a, 2z2b, 2z2c, and 2z2d are all in the positive direction of the X axis, the resistance values ​​of the third magnetic induction units 2z2a and 2z2c decrease, and the resistance values ​​of the third magnetic induction units 2z2b and 2z2d increase. Therefore, a push-pull full-bridge structure can be adopted, or a differential full-bridge structure can be formed based on additional resistance to sense the magnetic field to be measured in the Z axis direction and generate a differential voltage signal. In addition, an open-loop signal conditioning circuit can be used to condition, amplify, temperature compensate and linearly correct the generated differential voltage signal to form an output signal (first conditioned signal) of the third magnetic signal output circuit for detecting the third direction (i.e., the Z-axis direction).

[0058] Please refer to Figure 3 , Figure 3 The first magnetic flux path simulation schematic diagram provided in the embodiment of the present application. Specifically, Figure 3 For Figure 1 The magnetic flux path simulation diagram after the magnetic field to be measured in the positive direction of the Z axis is applied to the magnetic field measurement area 2z in the Z axis direction in the provided embodiment. 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 because the metal soft magnetic material is distributed at intervals, the magnetic circuit will be distorted in the X axis direction when it is converted between the first magnetic conductor 2z1 and the second magnetic conductor 2z3, and an X axis magnetic field component is generated at the location of the third magnetic induction unit (2z2a, 2z2b, 2z2c, 2z2d). This double-layer interval distribution soft magnetic array vertical detection structure (i.e., magnetic field measurement area 2z) adopted in the present application solves the problems of uneven magnetic field distribution, serious sensitivity loss, low precision, and high noise in the measurement direction of the long strip soft magnetic sheet arranged in a single-layer array, and enhances the magnetic field concentration effect and magnetic field uniformity, and the magnetic field conversion efficiency is higher, the sensitivity is improved, and the overall accuracy, sensitivity, and stability of the three-axis sensor are improved, and the noise is reduced.

[0059] In some optional embodiments, the sensor also includes: a first magnetically shielded magnetic induction unit (2x2b, 2x2d); the projection of the first magnetically shielded magnetic induction unit (2x2b, 2x2d) on the first substrate 1a is located within the magnetic conductive area of ​​the third magnetic conductive body 2x1; the sensor is based on the first magnetic induction unit (2x2a or 2x2c) located in the second air gap area and the first magnetically shielded magnetic induction unit (2x2b or 2x2d) to form a second magnetic signal output circuit for detecting the magnetic induction intensity in the second direction.

[0060] If the direction of the external magnetic field is the positive direction of the X-axis, the magnetic field to be measured is gathered and amplified by the metal soft magnetic material structure (the third magnetic conductor 2x1) to form a magnetic circuit, and the first magnetic induction unit (2x2a or 2x2c) detects the magnetic field along the positive direction of the X-axis after being gathered and amplified at the second air gap of the metal soft magnetic material structure (the third magnetic conductor 2x1), and the first magnetic shielding magnetic induction unit (2x2b or 2x2d) detects the magnetic field that is shielded and weakened by the metal soft magnetic material structure (the third magnetic conductor 2x1). Therefore, the resistance value of the first magnetic induction unit (2x2a or 2x2c) decreases, and the resistance value of the first magnetic shielding magnetic induction unit (2x2b or 2x2d) remains approximately unchanged, and a differential full-bridge structure or a differential half-bridge structure can be used to sense the magnetic field in the X-axis direction to generate a differential voltage signal. In addition, an open-loop signal conditioning circuit can be used to condition, amplify, temperature compensate and linearly correct the generated differential voltage signal to form an output signal (first conditioned signal) of the second magnetic signal output circuit for detecting the second direction (i.e., the X-axis direction); or a closed-loop signal conditioning circuit, a magnetic field feedback coil and a "first magnetic induction unit (2x2a or 2x2c) and a first magnetically shielded magnetic induction unit (2x2b or 2x2d)" can be used to form a closed-loop magnetic field feedback structure, and the generated differential voltage signal is amplified by a closed-loop signal conditioning circuit, and a feedback magnetic field is generated by a magnetic field feedback coil to achieve a dynamic balance of the magnetic field, and the feedback current of the magnetic field feedback coil is sampled to form an output signal (second conditioned signal) of the second magnetic signal output circuit for detecting the second direction (i.e., the X-axis direction).

[0061] In some optional embodiments, the fourth magnetic conductor 2y1 (2y1a and 2y1b, Figure 2 Only 2y1b is taken as an example, and the various parts included in the fourth magnetic conductor 2y1b are shown, including: a fourth magnetic field input area 2ya in the first direction located at both ends of the fourth magnetic conductor 2y1 and a fourth magnetic field conversion area 2yb located between the two ends of the fourth magnetic conductor 2y1; the fourth magnetic field conversion area 2yb includes a fourth magnetic field conversion magnetic circuit 2yc in the second direction; wherein the fourth magnetic field conversion magnetic circuit 2yc has the third air gap.

[0062] Among them, the direction of the fourth magnetic field input area refers to the direction of the magnetic induction intensity entering the fourth magnetic field input area 2ya, and the fourth magnetic field conversion magnetic circuit in the second direction is used to convert the "magnetic induction intensity to be measured in the first direction entering the fourth magnetic field input area 2ya" into the magnetic induction intensity in the second direction, and then based on the magnetic induction unit with "the magnetic induction sensitivity direction as the second direction", the measurement of the magnetic induction intensity in the first direction is realized.

[0063] In some optional embodiments, the third air gap includes a third conversion air gap and a fourth conversion air gap; the fourth magnetic field conversion magnetic circuit 2yc includes adjacent third conversion magnetic circuit 2yc1 and fourth conversion magnetic circuit 2yc2; the third conversion magnetic circuit 2yc1 has the third conversion air gap, and the fourth conversion magnetic circuit 2yc2 has the fourth conversion air gap; the sensor forms a first magnetic signal output circuit for detecting the magnetic induction intensity in the first direction based on the third conversion magnetic induction unit 2y2a and the fourth conversion magnetic induction unit 2y2b; wherein the third conversion magnetic induction unit 2y2a and the fourth conversion magnetic induction unit 2y2b are respectively located in the air gap area of ​​the third conversion air gap and the fourth conversion air gap.

[0064] The magnetic field measurement area 2y includes a fourth magnetic conductor 2y1 made of a high magnetic permeability metallic soft magnetic material. Figure 1 As shown, in this embodiment, the magnetic field measurement area 2y in the Y-axis direction of the multi-axis magnetic field sensor includes a fourth magnetic field input area 2ya in the first direction located at both ends of the fourth magnetic conductor 2y1 and a fourth magnetic field conversion area 2yb located between the two ends of the fourth magnetic conductor 2y1, and the fourth magnetic field conversion area 2yb includes a fourth magnetic field conversion magnetic circuit 2yc in the second direction; wherein the fourth magnetic field conversion magnetic circuit 2yc has the third air gap. The fourth magnetic conductor 2y1 can gather the magnetic flux of the input magnetic field in the detection direction and then twist the magnetic circuit at the corner to generate a magnetic field component perpendicular to the input magnetic field.

[0065] The example of the external magnetic field direction being the positive direction of the Y axis and the magnetic induction sensitivity direction of the second magnetic induction unit (2y2a, 2y2b) being the positive direction of the X axis is used for explanation. At this time, the magnetic circuit conversion zone located at the negative direction of the Y axis of the metal soft magnetic material structure 2y1 gathers the magnetic flux of the magnetic field to be measured in the positive direction of the Y axis and then distorts the magnetic circuit at the corner, and generates a magnetic field in the positive direction of the X axis at the fourth conversion air gap of the fourth conversion magnetic circuit 2yc2; then the metal soft magnetic material structure 2y1 uses the magnetic circuit conversion zone containing a U-shaped corner to distort the magnetic circuit in the positive direction of the X axis to the negative direction of the X axis and generates a magnetic field in the negative direction of the X axis at the third conversion air gap of the third conversion magnetic circuit 2yc1, and finally, the magnetic circuit is distorted back to the positive direction of the Y axis through the magnetic circuit conversion zone containing an L-shaped corner at the positive direction of the Y axis of the metal soft magnetic material structure 2y1 to achieve symmetry of the magnetic field measurement in the positive and negative directions of the Y axis. The second magnetic induction unit (2y2a, 2y2b) and the third magnetic induction unit (2z2a, 2z2b, 2z2c, 2z2d) are located in the same passivation layer and can be prepared by the same magnetoresistive thin film deposition process.

[0066] Please refer to Figure 4 , Figure 4 The second magnetic flux path simulation schematic diagram provided in the embodiment of the present application. Specifically, Figure 3 for Figure 1The magnetic flux path simulation diagram after the magnetic field measurement area 2y in the Y-axis direction in the provided embodiment is applied with the magnetic field to be measured in the positive direction of the Y-axis. It can be seen that the metal soft magnetic material structure (the fourth magnetic conductor 2y1) performs obvious magnetic flux aggregation and magnetic circuit distortion on the magnetic field to be measured in the positive direction of the Y-axis, and generates obvious components in the opposite direction of the X-axis at the location of the second magnetic induction units 2y2a and 2y2b. Therefore, the second magnetic induction units 2y2a and 2y2b, whose sensitivity directions are both in the positive direction of the X-axis, can form a push-pull half-bridge structure or a differential half-bridge structure based on additional resistance to sense the magnetic field in the Y-axis direction and generate a differential voltage signal. In addition, an open-loop signal conditioning circuit can be used to condition and amplify the generated differential voltage signal, perform temperature compensation and linearity correction on the generated differential voltage signal to form an output signal (first conditioned signal) of the first magnetic signal output circuit for detecting the first direction (i.e., the Y-axis direction); or a closed-loop signal conditioning circuit, a magnetic field feedback coil and a second magnetic induction unit (2y2a, 2y2b) can be used to form a closed-loop magnetic field feedback structure, and the generated differential voltage signal is amplified by the closed-loop signal conditioning circuit, and a feedback magnetic field is generated by the magnetic field feedback coil to achieve a dynamic balance of the magnetic field, and the feedback current of the magnetic field feedback coil is sampled to form an output signal (second conditioned signal) of the first magnetic signal output circuit for detecting the first direction (i.e., the Y-axis direction). The magnetic field feedback coil is a coil that surrounds the second substrate 1b along the XY plane.

[0067] exist Figure 1 In the specific implementation of the corresponding multi-axis magnetic field sensor, the measurement of the magnetic field to be measured in the three directions of X-axis, Y-axis and Z-axis can be realized based on the same substrate (first substrate 1a), and single-chip integrated manufacturing can be realized, with a small volume and good stability. In addition, the embodiment of the present application only uses a magnetic induction unit with the same sensitivity direction to realize the measurement of all three axes of X, Y and Z, so that the magnetoresistive film can be prepared on the same layer at one time, reducing the complexity of the operation steps, facilitating production, and having the advantages of good consistency, small temperature drift, high precision, good stability, and single-chip preparation. The Z-axis double-layer spaced distribution soft magnetic array detection structure (magnetic field measurement structure in the Z-axis direction) adopted in the present application has the characteristics of high sensitivity and low noise compared with the prior art.

[0068] It can be seen that the multi-axis magnetic field sensor provided by the present application forms a magnetic signal output circuit for measuring different magnetic induction intensity directions by means of magnetic induction units arranged in the corresponding air gap area. Since the magnetic induction units in the same passivation layer have the same magnetic induction sensitivity direction, the multi-axis magnetic field sensor provided by the present application can be prepared on a single chip, and the prepared multi-axis magnetic field sensor has better stability and higher accuracy, which solves the "technical problem that the existing three-axis magnetic field sensors have poor accuracy and are difficult to achieve single-chip integrated manufacturing".

[0069] like Figure 2 As shown, the multi-axis magnetic field sensor is implemented based on a double-substrate grooveless structure. In this embodiment, the metal soft magnetic material structures 2x1a and 2x1b used in the magnetic field measurement area 2x in the X-axis direction are symmetrically distributed on the first substrate 1a and the second substrate 1b about the XY plane; the metal soft magnetic material structures 2y1a and 2y1b used in the magnetic field measurement area 2y in the Y-axis direction are symmetrically distributed on the first substrate 1a and the second substrate 1b about the XY plane. The multi-axis magnetic field sensor includes: three long strips of metal soft magnetic materials (first magnetic conductors 2z1) for detecting the magnetic induction intensity in the Z-axis direction formed on the first substrate 1a by deposition and semiconductor micromachining, and multiple first magnetic conductors 2z1 are distributed at intervals in the X-axis direction. After the surface of the first magnetic conductor 2z1 is polished by CMP chemical mechanical polishing process and a passivation layer is deposited, an MR magnetoresistive film is deposited on the surface of the passivation layer and a third magnetic induction unit (2z2a, 2z2b, 2x2c and 2z2d) is formed by semiconductor graphic micromachining. After a passivation layer is deposited again on the third magnetic induction unit (2z2a, 2z2b, 2x2c and 2z2d) to protect the magnetoresistive film, two long strips of metal soft magnetic materials (second magnetic conductors 2z3) for detecting the magnetic induction intensity in the Z-axis direction are formed on the passivation layer through deposition and semiconductor micromachining. Multiple second magnetic conductors 2z3 are spaced apart in the X-axis direction. The MR magnetoresistive film used in the third magnetic induction unit can be a tunnel magnetoresistor TMR. Using a single chip packaging process, the lead pads, circuits, and mechanical support shells are added through the WLP wafer-level advanced packaging and TSV silicon through-hole process, and the first substrate 1a and the second substrate 1b are packaged with the surfaces where the tunnel magnetoresistor TMR is located facing each other. Figure 2 The figure shows that the projections of the first magnetic conductor 2z1 and the second magnetic conductor 2z3 on the first substrate do not overlap. The vertical projections of the magnetic induction units 2z2a, 2z2b, 2z2c, and 2z2d in the Z-axis direction (i.e., the projections of the magnetic induction units 2z2a, 2z2b, 2z2c, and 2z2d on the first substrate 1a) are located in the interval distribution area of ​​the metal soft magnetic materials of the first magnetic conductor 2z1 and the second magnetic conductor 2z3.

[0070] It should be noted that the structures of the magnetic field measurement area 2x in the X-axis direction and the magnetic field measurement area 2y in the Y-axis direction in the present application can be interchangeable. For example, after the XY plane where the first substrate 1a of this embodiment is located is rotated 90 degrees around the Z-axis, the original magnetic field measurement area 2x in the X-axis direction can be directly used as the magnetic field measurement area 2y in the Y-axis direction, and the original magnetic field measurement area 2y in the Y-axis direction can be directly used as the magnetic field measurement area 2x in the X-axis direction, and the magnetic field measurement area 2z in the Z-axis direction is not affected.

[0071] Please refer to Figure 5 , Figure 5This is a schematic diagram of the structure of the third multi-axis magnetic field sensor provided in the embodiment of the present application. Specifically, Figure 5 The upper part of the figure shows a schematic diagram of the projection structure of "the component between the passivation layer 1c2 and the second substrate 1b" in the multi-axis magnetic field sensor on the plane (XY plane) where the second substrate 1b is located. Figure 5 The middle part of the figure shows a schematic diagram of the projection structure of "the components between the passivation layer 1c1 and the first substrate 1a" in the multi-axis magnetic field sensor on the plane (XY plane) where the first substrate 1a is located. Figure 5 The lower part of FIG. 1 is a schematic diagram of the projection structure of the multi-axis magnetic field sensor on the XZ plane (the plane where the first substrate 1a or the second substrate 1b is located is the XY plane).

[0072] This embodiment uses two substrates, namely the first substrate 1a and the second substrate 1b located in the XY plane. The magnetic field measurement area 2z in the Z-axis direction senses the magnetic field in the Z-axis direction to be measured, the magnetic field measurement area 2x in the X-axis direction senses the magnetic field in the X-axis direction, and the magnetic field measurement area 2y in the Y-axis direction senses the magnetic field in the Y-axis direction. Figure 5 As shown, the first magnetic conductor 2z1 is arranged on the first substrate 1a; the second magnetic conductor 2z3 is arranged on the second substrate 1b; the third magnetic conductor 2x1 includes 2x1a and 2x1b, wherein 2x1a is arranged on the first substrate 1a, and 2x1b is arranged on the second substrate 1b; the fourth magnetic conductor 2y1 is arranged on the second substrate 1b.

[0073] For the magnetic field measurement area 2z in the Z-axis direction, Figure 5 As shown in the XZ section in FIG. 1 , MR magnetoresistive films using tunnel magnetoresistance TMR are deposited on the surfaces of the first substrate 1a and the second substrate 1b, and the third magnetic sensing units 2z2a and 2z2b are formed respectively by semiconductor graphic micromachining, and then a passivation layer is deposited to protect the magnetoresistive films. A groove is formed on the first substrate 1a and the second substrate 1b away from the MR magnetoresistive film by a reverse DRIE deep reactive ion etching process, and a metal soft magnetic material is deposited in the groove and polished by a CMP chemical mechanical polishing process, forming a first magnetic conductor 2z1 in the first substrate 1a and a second magnetic conductor 2z3 in the second substrate 1b. A single chip packaging process is adopted, and lead pads, circuits, and mechanical support shells are added through WLP wafer-level advanced packaging and TSV through silicon via processes. The first substrate 1a and the second substrate 1b are packaged with the surfaces where the tunnel magnetoresistance TMR is located facing each other, so that the sensitivity directions of the packaged third magnetic induction units 2z2a and 2z2b are opposite, which are respectively the positive direction of the X-axis and the negative direction of the X-axis, and the metal soft magnetic materials in the first magnetic conductor 2z1 and the second magnetic conductor 2z3 are as follows: Figure 5As shown, they are spaced apart in the X-axis direction and their projections in the Z-axis direction do not overlap; the projections of the third magnetic induction units 2z2a and 2z2b in the Z-axis direction are located in the spaced apart distribution area of ​​the metal soft magnetic materials of the first magnetic conductor 2z1 and the second magnetic conductor 2z3. It should be noted that, since the sensitivity directions of the third magnetic induction units 2z2a and 2z2b are opposite after packaging, in this embodiment, only one groove is etched on each of the first substrate 1a and the second substrate 1b, that is, the first magnetic conductor 2z1 and the second magnetic conductor 2z3 only use one long strip of metal soft magnetic material; in actual applications, more than one spaced apart grooves can be etched as needed. Since the reverse DRIE process is mainly used to enhance the magnetic focusing effect and improve the sensitivity, its measurement principle is basically the same as that of the aforementioned embodiment and will not be described in detail here.

[0074] Specifically, the magnetic field to be measured is in the positive direction of the Z axis, and the sensitivity direction of the third magnetic induction unit 2z2a is in the positive direction of the X axis, and the sensitivity direction of the magnetic induction unit 2z2b is in the negative direction of the X axis. In this case, the converted X-axis magnetic field component is in the positive direction of the X axis at the positions of the third magnetic induction units 2z2a and 2z2b, and the resistance value of the third magnetic induction unit 2z2a decreases, and the resistance value of the third magnetic induction unit 2z2b increases. Therefore, a push-pull half-bridge structure or a differential half-bridge structure with an additional reference resistor can be used to sense the magnetic field in the Z axis direction and generate a differential voltage signal. In addition, an open-loop signal conditioning circuit can be used to condition and amplify the generated differential voltage signal, perform temperature compensation and linearity correction on the generated differential voltage signal to form an output signal (first conditioned signal) of the third magnetic signal output circuit for detecting the third direction (i.e., the Z-axis direction); or a closed-loop signal conditioning circuit, a magnetic field feedback coil and a third magnetic induction unit (2z2a, 2z2b) can be used to form a closed-loop magnetic field feedback structure, and the generated differential voltage signal is amplified by the closed-loop signal conditioning circuit, and a feedback magnetic field is generated by the magnetic field feedback coil to achieve a dynamic balance of the magnetic field, and the feedback current of the magnetic field feedback coil is sampled to form an output signal (second conditioned signal) of the third magnetic signal output circuit for detecting the third direction. The magnetic field feedback coil is a coil that surrounds the second substrate 1b along the XY plane.

[0075] For the magnetic field measurement area 2x in the X-axis direction, MR magnetoresistive films are deposited on the surfaces of the first substrate 1a and the second substrate 1b respectively and semiconductor patterning micromachining is used to form the first magnetic sensing units 2x2a and 2x2c, and then a passivation layer is deposited to protect the magnetoresistive films. Figure 5As shown, grooves distributed at intervals are etched on the first substrate 1a and the second substrate 1b, respectively, and high magnetic permeability metal soft magnetic materials are deposited in the grooves to form metal soft magnetic material structures 2x1a and metal soft magnetic material structures 2x1b distributed at intervals. After packaging, the metal soft magnetic material structures 2x1a and 2x1b are symmetrically distributed in the first substrate 1a and the second substrate 1b about the XY plane. The first magnetic induction unit 2x2a and the third magnetic induction unit 2z2a are located in the same layer and use the same magnetoresistive film deposition process, and the sensitivity direction is the positive direction of the X axis; the first magnetic induction unit 2x2c and the third magnetic induction unit 2z2b are located in the same layer and use the same magnetoresistive film deposition process, and the sensitivity direction is the negative direction of the X axis; wherein the projection position of the first magnetic induction unit 2x2a and 2x2c along the Z axis direction is located in the interval air gap of the metal soft magnetic material distribution area. Take the magnetic field to be measured as the positive direction of the X-axis as an example for explanation. In this case, the magnetic fields at the first magnetic induction unit 2x2a and 2x2c are both in the positive direction of the X-axis, the resistance value of the first magnetic induction unit 2x2a decreases, and the resistance value of the first magnetic induction unit 2x2c increases. A push-pull full-bridge structure or a push-pull half-bridge structure can be used to sense the magnetic field in the X-axis direction to generate a differential voltage signal. An open-loop signal conditioning circuit can also be used to condition, amplify, temperature compensate and correct the linearity of the generated differential voltage signal to form an output signal (first conditioning signal) of the second magnetic signal output circuit for detecting the second direction (i.e., the X-axis direction); or a closed-loop signal conditioning circuit, a magnetic field feedback coil and "the first magnetic induction unit 2x2a and 2x2c" are used to form a closed-loop magnetic field feedback structure, and the generated differential voltage signal is amplified by the closed-loop signal conditioning circuit, and a feedback magnetic field is generated by the magnetic field feedback coil to achieve a dynamic balance of the magnetic field, and the feedback current of the magnetic field feedback coil is sampled to form an output signal (second conditioning signal) of the second magnetic signal output circuit for detecting the second direction.

[0076] For the magnetic field measurement area 2y in the Y-axis direction, the second magnetic sensing units 2y2a and 2y2b are formed on the same layer using the same magnetoresistive film deposition process as the third magnetic sensing unit 2z2b on the surface of the second substrate 1b, and then a passivation layer is deposited to protect the magnetoresistive film. After packaging, the sensitivity directions of the second magnetic sensing units 2y2a and 2y2b are both in the negative direction of the X-axis. Figure 5 As shown, a groove is etched on the second substrate 1b and a high magnetic permeability metal soft magnetic material is deposited in the groove to form a metal soft magnetic material structure 2y1. The shape of the metal soft magnetic material structure 2y1 in this embodiment is similar to Figure 1 The metal soft magnetic material structure 2y1 of the "magnetic field measurement area 2y in the Y-axis direction" in the corresponding embodiment has the same shape, and the main difference is that Figure 1The metal soft magnetic material in the corresponding embodiment is deposited on the second substrate 1b, while the metal soft magnetic material in this embodiment is deposited in the internal groove of the second substrate 1b. The projection position of the second magnetic induction units 2y2a and 2y2b in the Z-axis direction of this embodiment is located in the air gap of the metal soft magnetic material structure 2y1. Take the magnetic field to be measured as the positive direction of the Y-axis as an example for explanation. In this case, the resistance value of the second magnetic induction unit 2y2a decreases, and the resistance value of the second magnetic induction unit 2y2b increases. Therefore, the second magnetic induction units 2y2a, 2y2b and the reference resistor can be connected in series and parallel to form a differential full-bridge structure to sense the magnetic field in the Y-axis direction and generate a differential voltage signal. An open-loop signal conditioning circuit can also be used to condition, amplify, temperature compensate and linearly correct the generated differential voltage signal to form an output signal (first conditioned signal) of the first magnetic signal output circuit for detecting the first direction (i.e., the Y-axis direction); or a closed-loop signal conditioning circuit, a magnetic field feedback coil and "second magnetic induction unit 2y2a and 2y2b / second magnetic induction unit 2y2a and resistor / second magnetic induction unit 2y2b and resistor" can be used to form a closed-loop magnetic field feedback structure, and the generated differential voltage signal is amplified by a closed-loop signal conditioning circuit, and a feedback magnetic field is generated by a magnetic field feedback coil to achieve dynamic balance of the magnetic field, and the feedback current of the magnetic field feedback coil is sampled to form the output signal (second conditioned signal) of the first magnetic signal output circuit for detecting the first direction.

[0077] In summary, Figure 5 The multi-axis magnetic field sensor in the provided embodiment adopts a single chip packaging process on two substrates (the first substrate 1a and the second substrate 1b), and its characteristics are that during packaging, the sensitivity directions of the magnetic induction units on the first substrate 1a and the second substrate 1b are opposite, and they differ by 180 degrees in the XY plane, so it is easy to form a push-pull and differential structure between the two substrates; and the projections of the magnetic induction units on the first substrate 1a and the second substrate 1b on the Z axis can overlap, which improves consistency and accuracy. The packaging method of this embodiment can minimize the volume of the Z axis, that is, the first magnetic conductor 2z1 and the first magnetic conductor 2z3 each use only one piece of metal soft magnetic material to form a push-pull half-bridge structure, which is conducive to reducing the volume. At the same time, this embodiment adopts the reverse DRIE deep reactive ion etching process to form grooves, which can enhance the magnetic field gathering effect and improve the sensitivity, and solve the problems of low magnetic field conversion efficiency, sensitivity loss and high noise in the measurement direction of the magnetic flux gathering structure in the prior art.

[0078] Please refer to Figure 6 , Figure 6 This is a schematic diagram of the structure of the fourth multi-axis magnetic field sensor provided in the embodiment of the present application. Specifically, Figure 6The upper part of the figure shows a schematic diagram of the projection structure of the "fourth magnetic conductor, the second magnetic induction unit and the second magnetic shielding magnetic induction unit" in the multi-axis magnetic field sensor on the plane (XY plane) where the second substrate 1b is located. Figure 6 The middle part of the figure shows a schematic diagram of the projection structure of "the first magnetic conductor, the second magnetic conductor, the third magnetic conductor, the first magnetic induction unit, the first magnetic shielding magnetic induction unit and the third magnetic induction unit" in the multi-axis magnetic field sensor on the plane (XY plane) where the first substrate 1a is located. Figure 6 The lower part of FIG. 1 is a schematic diagram of the projection structure of the multi-axis magnetic field sensor on the XZ plane (the plane where the first substrate 1a or the second substrate 1b is located is the XY plane).

[0079] In some optional embodiments, the sensor also includes: a second magnetically shielded magnetic induction unit; the projection of the second magnetically shielded magnetic induction unit on the substrate is located within the magnetic conductive area of ​​the fourth magnetic conductive body; the sensor is based on the second magnetic induction unit located in the second air gap area and the second magnetically shielded magnetic induction unit to form a first magnetic signal output circuit for detecting the magnetic induction intensity in the first direction.

[0080] This embodiment uses two substrates, namely the first substrate 1a and the second substrate 1b located in the XY plane. The magnetic field measurement area 2z based on the Z-axis direction senses the magnetic field in the Z-axis direction to be measured, the magnetic field measurement area 2x based on the X-axis direction senses the magnetic field in the X-axis direction to be measured, and the magnetic field measurement area 2y based on the Y-axis direction senses the magnetic field in the Y-axis direction to be measured. Figure 6 As shown, the first magnetic conductor 2z1 is arranged on the first substrate 1a, and the second magnetic conductor 2z3, the third magnetic conductor 2x1 and the fourth magnetic conductor 2y1 are arranged on the passivation layer.

[0081] For the magnetic field measurement area 2z in the Z-axis direction, Figure 6 As shown in the XZ cross section in, grooves spaced apart in the X-axis direction are etched on the first substrate 1a, and high magnetic permeability metal soft magnetic material is deposited in the grooves to form metal soft magnetic material in long strips spaced apart, and polished by CMP chemical mechanical polishing process to form the first magnetic conductor 2z1. An MR magnetoresistive film using tunnel magnetoresistance TMR is deposited above the first magnetic conductor 2z1, and semiconductor graphic micromachining is used to form the third magnetic induction units 2z2a, 2z2b, 2z2c, and 2z2d, respectively, and then a passivation layer is deposited to protect the magnetoresistive film. Metal soft magnetic material is further deposited above the passivation layer, and semiconductor micromachining is used to form another layer of metal soft magnetic material in long strips spaced apart in the X-axis direction from the first magnetic conductor 2z1, forming the second magnetic conductor 2z3. As shown in FIG. Figure 6As shown, the projection of the MR magnetoresistive film along the Z-axis direction is located at a position less than 1 / 2 of the metal soft magnetic material on the inner side of the groove edge; the projections of the first magnetic conductor 2z1 and the second magnetic conductor 2z3 in the Z-axis direction (i.e., the projections on the substrate) have a partial overlapping area, and the overlapping area of ​​the projections of the first magnetic conductor 2z1 and the second magnetic conductor 2z3 on the substrate is less than half of the magnetic conductor area (the magnetic conductor area of ​​the first magnetic conductor 2z1 or the second magnetic conductor 2z3).

[0082] Specifically, the sensitivity direction of the third magnetic induction units 2z2a, 2z2b, 2z2c, and 2z2d is the positive direction of the X-axis. Taking the magnetic field to be measured as the positive direction of the Z-axis as an example, in this case, the converted X-axis magnetic field components are all in the positive direction of the X-axis at the positions of the third magnetic induction units 2z2a and 2z2c, and are all in the negative direction of the X-axis at the positions of the third magnetic induction units 2z2b and 2z2d. The resistance values ​​of the third magnetic induction units 2z2a and 2z2c decrease, and the resistance values ​​of the third magnetic induction units 2z2b and 2z2d increase. Therefore, a push-pull full-bridge structure can be used to sense the magnetic field in the Z-axis direction to generate a differential voltage signal. In addition, an open-loop signal conditioning circuit can be used to condition, amplify, temperature compensate, and correct the linearity of the generated differential voltage signal to form an output signal (first conditioning signal) of the second magnetic signal output circuit for detecting the second direction (i.e., the X-axis direction).

[0083] For the magnetic field measurement area 2x in the X-axis direction, an MR magnetoresistive film is deposited on the surface of the first substrate 1a and a first magnetic induction unit (2x2a, 2x2c) and a first magnetic shielding magnetic induction unit (2x2b, 2x2d) are formed by semiconductor graphic micromachining, and then a passivation layer is deposited to protect the magnetoresistive film. The first magnetic induction unit, the first magnetic shielding magnetic induction unit and the third magnetic induction unit (2z2a, 2z2b, 2z2c, 2z2d) are located in the same layer and adopt the same magnetoresistive film deposition process, and the sensitivity direction is all in the positive direction of the X-axis. Figure 6 As shown, the third magnetic conductor 2x1 and the second magnetic conductor 2z3 are located in the same layer and adopt the same deposition process. Through deposition and semiconductor micromachining, a long strip area with interval distribution is formed above the magnetoresistive film passivation layer; the projection position of the first magnetic induction unit 2x2a, 2x2c along the Z-axis direction is located in the interval air gap of the metal soft magnetic material interval distribution area, and the projection position of the first magnetic shielding magnetic induction unit 2x2b, 2x2d along the Z-axis direction is located in the metal soft magnetic material projection coverage area. Take the magnetic field to be measured as the positive direction of the X-axis as an example for explanation. In this case, the resistance values ​​of the first magnetic induction units 2x2a, 2x2c decrease, and the resistance values ​​of the first magnetic shielding magnetic induction units 2x2b, 2x2d remain approximately unchanged. The differential full-bridge structure can be used to sense the magnetic field in the X-axis direction to generate a differential voltage signal.

[0084] For the magnetic field measurement area 2y in the Y-axis direction, the second magnetic induction unit (2y2a, 2y2b), the second magnetic shielding magnetic induction unit (2y2c, 2y2d) and the fourth magnetic conductor 2y1 are formed by exactly the same process. 2y2 represents the magnetic induction unit in the magnetic field measurement area 2y in the Y-axis direction (in this embodiment, it includes: the second magnetic induction unit 2y2a, 2y2b and the second magnetic shielding magnetic induction unit 2y2c, 2y2d). It should be noted that when a single chip packaging process is used, the first substrate 1a and the second substrate 1b are packaged relative to each other with the surfaces where the tunnel magnetoresistance TMR is located by adding lead pads, circuits, and mechanical support shells through WLP wafer-level advanced packaging and TSV silicon through-hole process, it is necessary to make the magnetic induction sensitivity direction of the packaged second magnetic induction unit perpendicular to that of the "first magnetic induction unit or the third magnetic induction unit". In this embodiment, Figure 6 As shown, the magnetic induction sensitivity direction of the second magnetic induction unit is the negative direction of the Y axis, and the magnetic induction sensitivity direction of the first magnetic induction unit or the third magnetic induction unit is the positive direction of the X axis.

[0085] In summary, the multi-axis magnetic field sensor provided in this embodiment adopts a single chip packaging process on two substrates 1, and its characteristic is that during packaging, the sensitivity directions of the magnetic induction units on the first substrate 1a and the second substrate 1b are perpendicular, and differ by 90 degrees in the XY plane. Therefore, the magnetic field measurement area 2x in the X-axis direction and the magnetic field measurement area 2z in the X-axis direction can adopt the same measurement structure, which is simple in structure and reduces cost.

[0086] Please refer to Figure 7 , Figure 7 This is a schematic diagram of the structure of the fifth multi-axis magnetic field sensor provided in the embodiment of the present application. Specifically, Figure 7 The upper part of the figure shows a schematic diagram of the projection structure of the "first magnetic induction unit, the first magnetic shielding magnetic induction unit and the fourth magnetic conductor" in the multi-axis magnetic field sensor on the plane (XY plane) where the first substrate 1a is located. Figure 7 The middle part of the figure shows a schematic diagram of the projection structure of "the second magnetic induction unit, the second magnetic shielding magnetic induction unit, the third magnetic induction unit, the first magnetic conductor, the second magnetic conductor and the third magnetic conductor" in the multi-axis magnetic field sensor on the plane (XY plane) where the second substrate 1b is located. Figure 7 The lower part of the figure shows a schematic diagram of the projection structure of the multi-axis magnetic field sensor on the XZ plane (the plane where the first substrate 1a or the second substrate 1b is located is the XY plane). 2y2 represents the magnetic induction unit in the magnetic field measurement area 2y in the Y-axis direction (including: second magnetic induction units 2y2a, 2y2b in this embodiment).

[0087] In some optional embodiments, the third magnetic conductor 2x1 includes: a third magnetic field input zone in the second direction located at both ends of the third magnetic conductor 2x1 and a third magnetic field conversion zone located between the two ends of the third magnetic conductor; the third magnetic field conversion zone includes a third magnetic field conversion magnetic circuit in the first direction; wherein the third magnetic field conversion magnetic circuit has the second air gap.

[0088] In some optional embodiments, the second air gap includes a first conversion air gap and a second conversion air gap; the third magnetic field conversion magnetic circuit includes adjacent first conversion magnetic circuit and second conversion magnetic circuit; the first conversion magnetic circuit has the first conversion air gap, and the second conversion magnetic circuit has the second conversion air gap; the sensor forms a second magnetic signal output circuit for detecting the magnetic induction intensity in the second direction based on the first conversion magnetic induction unit and the second conversion magnetic induction unit; wherein the first conversion magnetic induction unit and the second conversion magnetic induction unit are respectively located in the air gap areas of the first conversion air gap and the second conversion air gap.

[0089] This embodiment uses two substrates, namely the first substrate 1a and the second substrate 1b located in the XY plane. The magnetic field measurement area 2z based on the Z-axis direction senses the magnetic field in the Z-axis direction to be measured, the magnetic field measurement area 2x based on the X-axis direction senses the magnetic field in the X-axis direction to be measured, and the magnetic field measurement area 2y based on the Y-axis direction senses the magnetic field in the Y-axis direction to be measured. Figure 7 As shown, the first magnetic conductor 2z1 is arranged on the first substrate 1a, and the second magnetic conductor 2z3, the third magnetic conductor 2x1 and the fourth magnetic conductor 2y1 are arranged on the passivation layer.

[0090] For the magnetic field measurement area 2x in the X-axis direction, an MR magnetoresistive film using anisotropic magnetoresistance AMR is deposited on the surface of the first substrate 1a and semiconductor graphic micromachining is performed to form a first magnetic induction unit (2x2a, 2x2c). In this embodiment, the magnetic induction sensitivity direction of the first magnetic induction unit (2x2a, 2x2c) located on the first substrate 1a is the negative direction of the Y axis. After that, a passivation layer is deposited to protect the magnetoresistive film, and then a metal soft magnetic material is further deposited on the passivation layer, and a third magnetic conductor 2x1 is formed by semiconductor micromachining. Among them, the third magnetic conductor 2x1 in this embodiment includes a magnetic circuit conversion area of ​​a metal soft magnetic material with a corner, and its shape is similar to Figure 2 The corresponding embodiment is a combination of the shape of the fourth magnetic conductor 2y1. Figure 7As shown in the XY cross section in FIG. 1 , the metal soft magnetic material structure 2x1 includes two metal soft magnetic material structures parallel to the XY plane and symmetrical about the X axis, thereby being able to form two symmetrical magnetic flux paths in parallel. For the metal soft magnetic material structure 2x1 in the positive direction of the Y axis, the magnetic field to be measured in the positive direction of the X axis is taken as an example for explanation. In this case, the magnetic circuit conversion area including the L-shaped corner at the negative direction of the X axis of the metal soft magnetic material structure 2x1 gathers the magnetic flux of the magnetic field to be measured in the positive direction of the X axis and then distorts the magnetic circuit at the corner to generate a magnetic field in the positive direction of the Y axis and pass through the air gap where the Z axis projection of the first magnetic induction unit 2x2a is located; then the metal soft magnetic material structure 2x1 uses the magnetic circuit conversion area including the U-shaped corner to distort the magnetic circuit in the positive direction of the Y axis to the negative direction of the Y axis and pass through the air gap where the Z axis projection of the second magnetic induction unit 2x2c is located, and finally the magnetic circuit is distorted back to the positive direction of the X axis through the magnetic circuit conversion area including the L-shaped corner at the positive direction of the X axis of the metal soft magnetic material structure 2x1 to achieve symmetry of the magnetic field measurement in the positive and negative directions of the X axis. Therefore, the metal soft magnetic material structure 2x1 in the positive direction of the Y axis is connected in series with the same magnetic circuit. The metal soft magnetic material structure of half of the negative direction of the Y axis in the metal soft magnetic material structure 2x1 is symmetrical with the metal soft magnetic material structure of half of the positive direction of the Y axis about the X axis, that is, the magnetic circuit after the magnetic field to be measured in the positive direction of the X axis is distorted by the magnetic circuit conversion zone is in the positive direction of the Y axis at the air gap where the Z axis projection of the first magnetic induction unit 2x2a is located, and in the negative direction of the Y axis at the air gap where the Z axis projection of the first magnetic induction unit 2x2c is located. The metal soft magnetic material structure of half of the positive direction of the Y axis in the metal soft magnetic material structure 2x1 is connected in series to the same magnetic circuit. Therefore, the two magnetic circuits formed by the metal soft magnetic materials of half of the positive direction and half of the negative direction of the Y axis in the metal soft magnetic material structure 2x1 of this embodiment are connected in parallel with each other.

[0091] Please refer to Figure 8 , Figure 8 The third magnetic flux path simulation schematic diagram provided in the embodiment of the present application. Specifically, Figure 8 For Figure 7 The magnetic flux path simulation diagram after the magnetic field measurement area 2x in the X-axis direction in the provided embodiment is applied with the magnetic field to be measured in the positive direction of the X-axis. It can be seen that the metal soft magnetic material structure 2x1 performs obvious magnetic flux aggregation and magnetic circuit distortion on the magnetic field to be measured in the positive direction of the X-axis, forming two parallel magnetic flux paths symmetrical about the X-axis, and generating obvious components in the opposite direction of the Y-axis at the location of the first magnetic induction units 2x2a and 2x2c. Therefore, the magnetic induction units 2x2a and 2x2c, whose sensitivity directions are both in the negative direction of the Y-axis, can form a push-pull full-bridge structure to sense the magnetic field in the X-axis direction and generate a differential voltage signal.

[0092] For the magnetic field measurement area 2y in the Y-axis direction, the measurement principle is similar to that of the magnetic field measurement area 2x in the X-axis direction, and the magnetic field measurement area 2y and the magnetic field measurement area 2z in the Z-axis direction share some metal soft magnetic materials. Specifically, for the magnetic field measurement area 2y in the Y-axis direction, an MR magnetoresistive film is deposited on the surface of the second substrate 1b and processed by semiconductor graphic micromachining, such as Figure 7 As shown in the XY cross section in FIG, a second magnetic induction unit (2y2a, 2y2b) with a sensitivity direction in the positive direction of the X axis is formed, and then a passivation layer is deposited to protect the magnetoresistive film, and then a metal soft magnetic material is further deposited on the passivation layer, and a fourth magnetic conductor 2y1 is formed by semiconductor micromachining. The second magnetic induction unit (2y2a, 2y2b) forms a push-pull full-bridge structure to sense the magnetic field in the Y axis direction and generate a differential voltage signal.

[0093] For the magnetic field measurement area 2z in the Z-axis direction, the third magnetic sensing unit (2z2a, 2z2b) and the second magnetic sensing unit (2y2a, 2y2b) are located in the same layer and adopt the same magnetoresistive film deposition process, such as Figure 7 As shown, the magnetic induction units 2z2a and 2z2b are formed with their sensitivity directions being in the positive direction of the X axis, and then a passivation layer is deposited to protect the magnetoresistive film. It should be noted that the second magnetic conductor 2z3 and the fourth magnetic conductor 2y1 of this embodiment share some metal soft magnetic materials, that is, Figure 7 The metal soft magnetic material at one end of the metal soft magnetic material structure 2y1 in the positive direction of the X axis also serves as the metal soft magnetic material at one end of the second magnetic conductor 2z3 in the negative direction of the X axis. Therefore, for the magnetic field measurement area 2z of this embodiment, after forming the third magnetic induction units 2z2a and 2z2b protected by the passivation layer, Figure 7 As shown, a groove is etched on the second substrate 1b at a position spaced apart from the metal soft magnetic material shared with the above-mentioned part in the positive direction of the X-axis, and a high magnetic permeability metal soft magnetic material is deposited in the groove to form a long strip area of ​​metal soft magnetic material to constitute the first magnetic conductor 2z1. The second magnetic conductor 2z3 is located in the same layer as the metal soft magnetic material structure 2y1 and adopts the same deposition and semiconductor micromachining process. In addition to containing the metal soft magnetic material shared by the above-mentioned part, it also contains another long strip of metal soft magnetic material located above the magnetoresistive film passivation layer and spaced apart from the first magnetic conductor 2z1 in the positive direction of the X-axis. The projection of the third magnetic induction unit 2z2a in the Z-axis direction is located at the gap between the first magnetic conductor 2z1 and the metal soft magnetic material shared by the above-mentioned part; the projection of the third magnetic induction unit 2z2b in the Z-axis direction is located at the gap between the first magnetic conductor 2z1 and another long strip of metal soft magnetic material of the second magnetic conductor 2z3.

[0094] Specifically, the sensitivity direction of the third magnetic induction units 2z2a and 2z2b is the positive direction of the X-axis. The example of the magnetic field to be measured being the positive direction of the Z-axis is used for explanation. In this case, the converted X-axis magnetic field component is in the positive direction of the X-axis at the position of the third magnetic induction unit 2z2a, and is in the negative direction of the X-axis at the position of the third magnetic induction unit 2z2b. Therefore, a push-pull half-bridge structure can be used to sense the magnetic field in the Z-axis direction to generate a differential voltage signal. It should be noted in the present embodiment that when a single chip packaging process is used, the first substrate 1a and the second substrate 1b are packaged relative to the surface where the MR magnetoresistive film is located through the WLP wafer-level advanced packaging and the TSV silicon through-hole process with additional lead pads, circuits, and mechanical support housings, and the magnetic induction sensitivity directions of the packaged first magnetic induction unit and the "second magnetic induction unit or the third magnetic induction unit" need to be perpendicular to each other. In the present embodiment, Figure 7 As shown, the magnetic induction sensitivity direction of the first magnetic induction unit is the negative direction of the Y axis, and the magnetic induction sensitivity direction of the second magnetic induction unit or the third magnetic induction unit is the positive direction of the X axis.

[0095] In summary, the multi-axis magnetic field sensor provided in this embodiment adopts a single chip packaging process on two substrates 1. Figure 6 The corresponding embodiments are the same, and their characteristics are that the sensitivity directions of the magnetic induction units on the first substrate 1a and the second substrate 1b are perpendicular during packaging, and differ by 90 degrees in the XY plane. The difference is that the metal soft magnetic material structures 2x1 and 2y1 in this embodiment each use two magnetic circuits parallel to the XY plane and symmetrical about the X axis or the Y axis to form a push-pull full-bridge structure; its advantage is that only one magnetic induction unit with the same sensitivity direction is prepared on each substrate, so that push-pull bridge measurement can be achieved on the three axes of X, Y, and Z; compared with the ordinary differential full-bridge structure in which part of the resistance changes with the magnetic field and part of the resistance is approximately unchanged, this embodiment has higher sensitivity, better consistency, and higher precision. In addition, different detection modules in this embodiment directly share part of the metal soft magnetic material, which is conducive to saving costs and reducing volume.

[0096] In some optional embodiments, the sensor also includes: an external magnetic field magnetic induction unit 2A; the distances between the external magnetic field magnetic induction unit 2A and the first magnetic conductor 2z1, the second magnetic conductor 2z3, the third magnetic conductor 2x1 and the fourth magnetic conductor 2y1 are all greater than a preset distance; the sensor is respectively based on the magnetic induction unit and the external magnetic field magnetic induction unit 2A to form a magnetic signal output circuit for measuring different magnetic induction intensity directions.

[0097] It should be noted that when the distance between the external magnetic field magnetic induction unit 2A and the metal soft magnetic material is greater than the third preset distance, the external magnetic field magnetic induction unit 2A will be directly affected by the external magnetic field, and the third preset distance can be determined according to the actual magnetic induction range.

[0098] In some optional embodiments, the sensor further includes: a resistor (preferably, the resistor is a fixed-value resistor); the sensor forms a magnetic signal output circuit for measuring different directions of magnetic induction intensities based on the magnetic induction unit and the resistor.

[0099] An embodiment of the present application further provides a multi-axis magnetic field sensor chip, which is packaged by any of the multi-axis magnetic field sensors described in the first aspect through WLP wafer-level packaging and TSV through silicon via processes.

[0100] It should be understood that the multi-axis magnetic field sensor chip has corresponding content with the above-mentioned embodiment of the multi-axis magnetic field sensor. The specific functional implementation of the multi-axis magnetic field sensor chip can refer to the specific description of the multi-axis magnetic field sensor above. To avoid repetition, the detailed description is appropriately omitted here.

[0101] The functional modules in each embodiment of the present application may be integrated together to form an independent part, or each module may exist separately, or two or more modules may be integrated to form an independent part.

[0102] The above description is only an optional implementation manner of the embodiments of the present application, but the protection scope of the embodiments of the present application is not limited thereto. Any technician familiar with the technical field can easily think of changes or replacements within the technical scope disclosed in the embodiments of the present application, which should be covered within the protection scope of the embodiments of the present application.

Claims

1. A multi-axis magnetic field sensor, characterized in that: The sensor comprises: At least one first magnetic conductor disposed in a third direction on the first substrate; At least one second magnetic conductor in the third direction is arranged on the passivation layer or the second substrate; the difference in number between the first magnetic conductor and the second magnetic conductor is less than 2, and the projections of the first magnetic conductor and the second magnetic conductor on the substrate do not have an overlapping area or the overlapping area is less than half of the magnetic area of ​​the magnetic conductor; wherein the substrate is the first substrate or the second substrate, and the magnetic area of ​​the magnetic conductor is the magnetic area of ​​the first magnetic conductor or the magnetic area of ​​the second magnetic conductor; A first air gap, wherein the first air gap is formed based on the first magnetic conductor and the second magnetic conductor; A third magnetic conductor disposed in a second direction on the substrate or the passivation layer, wherein the third magnetic conductor has a second air gap; A fourth magnetic conductor in a first direction disposed on the substrate or the passivation layer, the fourth magnetic conductor having a third air gap; wherein the first direction, the second direction and the third direction are perpendicular to each other; At least three magnetic induction units, wherein the magnetic induction units are respectively located in corresponding air gap areas; wherein the air gap areas include the air gap areas of the first air gap, the second air gap and the third air gap, and the sensors respectively form magnetic signal output circuits for measuring different magnetic induction intensity directions based on the magnetic induction units; wherein the passivation layer is a passivation protection layer around the magnetic induction units, and the magnetic induction units in the same passivation layer have the same magnetic induction sensitivity direction.

2. The sensor according to claim 1, characterized in that in, The third magnetic conductor includes: a third magnetic field input area in the second direction located at both ends of the third magnetic conductor and a third magnetic field conversion area located between the two ends of the third magnetic conductor; the third magnetic field conversion area includes a third magnetic field conversion magnetic circuit in the first direction; wherein the third magnetic field conversion magnetic circuit has the second air gap.

3. The sensor according to claim 2, characterized in that in, The second air gap includes a first conversion air gap and a second conversion air gap; the third magnetic field conversion magnetic circuit includes adjacent first conversion magnetic circuit and second conversion magnetic circuit; the first conversion magnetic circuit has the first conversion air gap, and the second conversion magnetic circuit has the second conversion air gap; The sensor forms a second magnetic signal output circuit for detecting the magnetic induction intensity in the second direction based on a first conversion magnetic induction unit and a second conversion magnetic induction unit; wherein the first conversion magnetic induction unit and the second conversion magnetic induction unit are respectively located in the air gap areas of the first conversion air gap and the second conversion air gap.

4. The sensor according to claim 3, characterized in that in, The fourth magnetic conductor includes: a fourth magnetic field input area in the first direction located at both ends of the fourth magnetic conductor and a fourth magnetic field conversion area located between the two ends of the fourth magnetic conductor; the fourth magnetic field conversion area includes a fourth magnetic field conversion magnetic circuit in the second direction; wherein the fourth magnetic field conversion magnetic circuit has the third air gap.

5. The sensor according to claim 4, characterized in that in, The third air gap includes a third conversion air gap and a fourth conversion air gap; the fourth magnetic field conversion magnetic circuit includes adjacent third conversion magnetic circuits and fourth conversion magnetic circuits; the third conversion magnetic circuit has the third conversion air gap, and the fourth conversion magnetic circuit has the fourth conversion air gap; The sensor forms a first magnetic signal output circuit for detecting the magnetic induction intensity in the first direction based on a third conversion magnetic induction unit and a fourth conversion magnetic induction unit; wherein the third conversion magnetic induction unit and the fourth conversion magnetic induction unit are respectively located in the air gap areas of the third conversion air gap and the fourth conversion air gap.

6. The sensor according to claim 1, characterized in that The sensor further comprises: a first magnetic shielding magnetic induction unit; the projection of the first magnetic shielding magnetic induction unit on the substrate is located in the magnetic conductive area of ​​the third magnetic conductive body; The sensor forms a second magnetic signal output circuit for detecting the magnetic induction intensity in the second direction based on the first magnetic induction unit located in the second air gap area and the first magnetic shielding magnetic induction unit.

7. The sensor according to claim 6, characterized in that The sensor further comprises: a second magnetic shielding magnetic induction unit; the projection of the second magnetic shielding magnetic induction unit on the substrate is located in the magnetic conductive area of ​​the fourth magnetic conductive body; The sensor forms a first magnetic signal output circuit for detecting the magnetic induction intensity in the first direction based on the second magnetic induction unit located in the third air gap area and the second magnetic shielding magnetic induction unit.

8. The sensor according to claim 1, characterized in that The sensor further includes: an external magnetic field magnetic induction unit; the distances between the external magnetic field magnetic induction unit and the first magnetic conductor, the second magnetic conductor, the third magnetic conductor and the fourth magnetic conductor are all greater than a preset distance; The sensor forms a magnetic signal output circuit for measuring directions of different magnetic induction intensities based on the magnetic induction unit and the external magnetic field magnetic induction unit.

9. The sensor according to claim 1, characterized in that in, The grooves in the substrate are etched using a reverse DRIE deep reactive ion etching process, and after a metal soft magnetic material is deposited in the grooves, the grooves are polished using a CMP chemical mechanical polishing process.

10. The sensor according to any one of claims 1 to 9, characterized in that: The sensor further includes: an open-loop signal conditioning circuit; the open-loop signal conditioning circuit is electrically connected to the magnetic signal output circuit; the sensor performs conditioning amplification, temperature compensation and / or linearity correction on the electrical signal output by the magnetic signal output circuit based on the open-loop signal conditioning circuit to obtain a first conditioned signal; and outputs the first conditioned signal; or, The sensor also includes: a closed-loop signal conditioning circuit and a magnetic field feedback coil; the sensor forms a closed-loop magnetic field feedback structure based on the closed-loop signal conditioning circuit, the magnetic field feedback coil and the magnetic induction unit; the sensor conditions and amplifies, temperature compensates and / or linearizes the electrical signal output by the magnetic signal output circuit based on the closed-loop magnetic field feedback structure, and generates a feedback magnetic field to achieve a dynamic balance of the magnetic field, thereby obtaining a second conditioning signal; and outputs the second conditioning signal; wherein the second conditioning signal represents the feedback current of the magnetic field feedback coil when the magnetic field reaches a dynamic balance state.

11. A multi-axis magnetic field sensor chip, characterized in that: The chip is packaged by the multi-axis magnetic field sensor described in any one of claims 1 to 10 through WLP wafer-level packaging and TSV through silicon via processes.

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