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

Abstract

A multi-axis magnetic field sensor and a multi-axis magnetic field sensor chip. The multi-axis magnetic field sensor comprises: a first magnetizer (2z1), which is arranged on a first substrate (1a); a second magnetizer (2z3), which is arranged on a passivation layer (1c) or a second substrate (1b); a first air gap, which is formed on the basis of the first magnetizer (2z1) and the second magnetizer (2z3); a third magnetizer (2x1), which has a second air gap and is arranged on the substrate (1a or 1b) or the passivation layer (1c); a fourth magnetizer (2y1), which has a third air gap and is arranged on the substrate (1a or 1b) or the passivation layer (1c); and at least three magnetic induction units (at least one of 2x2a and 2x2c, at least one of 2y2a and 2y2b, and at least one of 2z2a, 2z2b, 2x2c and 2z2d), which are respectively located in corresponding air gap regions, wherein the magnetic induction units in the passivation layer (1c) have the same magnetic induction sensitivity direction. Magnetic induction units in the same passivation layer of the multi-axis magnetic field sensor have the same magnetic induction sensitivity direction, such that the single-chip manufacturing of the multi-axis magnetic field sensor can be realized, and the manufactured multi-axis magnetic field sensor achieves better stability and higher precision.

Description

Multi-axis magnetic field sensor and multi-axis magnetic field sensor chip 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] A magnetic sensor is a device that converts changes in the magnetic properties of a sensitive element caused by external factors such as magnetic field, current, stress and strain, temperature, and light into electrical signals, and detects the corresponding physical quantities in this way. It is 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 multi-chip packaging, for example, combining a horizontal (XY axis) magnetic field sensor with a vertical (Z axis) magnetic field sensor. Existing three-axis magnetic field sensors have poor accuracy, are difficult to manufacture on a single chip, and have poor vertical magnetic field focusing.

[0004] Summary of the Invention

[0005] 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 of the existing three-axis magnetic field sensor having poor accuracy and difficulty in single-chip integrated manufacturing.

[0006] 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;

[0007] At least one second magnetic conductor in the third direction is provided 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 overlap or the overlapping area is less than half of the magnetic conductive area of ​​the magnetic conductor; wherein the substrate is the first substrate or the second substrate, and the magnetic conductive area of ​​the magnetic conductor is the magnetic conductive area of ​​the first magnetic conductor or the magnetic conductive area of ​​the second magnetic conductor;

[0008] a first air gap formed based on the first magnetic conductor and the second magnetic conductor;

[0009] 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;

[0010] A fourth magnetic conductor disposed in a first direction 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;

[0011] At least three magnetic induction units, each of which is located in a corresponding air gap area; wherein the air gap area includes the air gap area of ​​the first air gap, the second air gap, and the third air gap; the sensor forms a magnetic signal output circuit for measuring different magnetic induction intensity directions based on the magnetic induction units; wherein the passivation layer is a passivation protective layer around the magnetic induction units, and the magnetic induction units within the same passivation layer have the same magnetic induction sensitivity direction.

[0012] In the above-mentioned 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 having a second air gap, a fourth magnetic conductor having a third air gap, and at least three magnetic induction units. A magnetic signal output circuit for measuring different magnetic induction intensity directions 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, a single-chip preparation of the multi-axis magnetic field sensor can be achieved, and the prepared multi-axis magnetic field sensor has better stability and higher accuracy. The use of 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 achieve single-chip integrated manufacturing."

[0013] In addition, the present application adopts a double-layer spaced-spaced soft magnetic array vertical detection structure (i.e., a vertical magnetic field measurement area formed by a first magnetic conductor and a 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. It 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.

[0014] Optionally, in an embodiment of the present application, 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.

[0015] 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 the magnetic field component to be measured in the first direction, and then the 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.

[0016] 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.

[0017] 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 magnetic field to be measured 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 opposite directions, thereby more sensitively reflecting the changes in the magnetic field to be measured 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.

[0018] Optionally, in an embodiment of the present application, 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.

[0019] 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 the magnetic field component to be measured in the second direction, and then the 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.

[0020] 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.

[0021] 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 magnetic field to be measured enters 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. The resistance values ​​of the third conversion magnetic induction unit and the fourth conversion magnetic induction unit will change in opposite directions, thereby more sensitively reflecting the changes in the magnetic field to be measured 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.

[0022] 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 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 magnetically shielded magnetic induction unit.

[0023] In the above implementation, because the projection of the first magnetic shielding induction unit on the substrate is located within the magnetic conductive region of the third magnetic conductor, the magnetic field signal detected by the first magnetic shielding induction unit is weakened by the third magnetic conductor. Therefore, compared to the change in resistance of the first magnetic induction unit, the resistance of the first magnetic shielding induction unit remains substantially unchanged. The second magnetic signal output circuit formed by the first magnetic induction unit and the first magnetic shielding magnetic induction unit, which is used to detect the magnetic induction intensity in the second direction, has a low sensitivity and can have a larger magnetic field intensity detection range, thereby achieving low-sensitivity measurement of the magnetic induction intensity in the second direction over a wide range.

[0024] 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 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 magnetically shielded magnetic induction unit.

[0025] In the above implementation, because the projection of the second magnetic shielding induction unit on the substrate is located within the magnetic conductive region of the fourth magnetic conductor, the magnetic field signal detected by the second magnetic shielding induction unit is weakened by the fourth magnetic conductor. Therefore, compared to the change in resistance of the second magnetic induction unit, the resistance of the second magnetic shielding induction unit remains substantially 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 low sensitivity, thus having a larger magnetic field intensity detection range, thereby enabling low-sensitivity measurement of the magnetic induction intensity in the first direction over a wide range.

[0026] Optionally, in an embodiment of the present application, 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 different magnetic induction intensity directions based on the magnetic induction unit and the external magnetic field magnetic induction unit.

[0027] In the above implementation process, because the distance between the external magnetic field magnetic induction unit and the first, second, third, and fourth magnetic conductors is relatively far (greater than a predetermined distance), the external magnetic field magnetic induction unit is directly affected by the external magnetic field (the external magnetic field refers to the external magnetic field to be measured, as compared to the magnetic field within the first, second, third, and fourth magnetic conductors). 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, thereby achieving a wide range of low-sensitivity measurement of magnetic induction intensity in different directions.

[0028] 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, the grooves are polished using a CMP chemical mechanical polishing process.

[0029] In the above implementation process, the reverse DRIE deep reactive ion etching process is used to form grooves, which can enhance the magnetic concentration effect and improve the sensitivity, and solve the technical problems in the existing technology that the magnetic flux concentration structure has low magnetic field conversion efficiency in the measurement direction, sensitivity loss, and high noise.

[0030] 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 magnetic induction intensity directions based on the magnetic induction unit and the resistor.

[0031] In the above implementation, a magnetic signal output circuit for measuring magnetic induction intensities in different directions can be formed using resistors and corresponding magnetic induction units. This simplifies the structure and reduces the difficulty of actual process packaging. Furthermore, the magnetic signal output circuit formed by the resistors and corresponding magnetic induction units has low sensitivity, allowing for a wider magnetic field strength detection range, enabling low-sensitivity measurement of magnetic induction intensities in different directions over a wide range.

[0032] Optionally, in an embodiment of the present application, 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 linearly corrects 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 linearly corrects 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 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.

[0033] 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.

[0034] 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.

[0035] A multi-axis magnetic field sensor provided by the present application is used to form a magnetic signal output circuit for measuring different magnetic induction intensity directions by means of magnetic induction units arranged in corresponding air gap areas. 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, solving 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

[0036] In order to more clearly illustrate the technical solutions of the embodiments of the present application, the following is a brief introduction to the drawings required for use in the embodiments of the present application. It should be understood that the following drawings only show certain embodiments of the present application and therefore should not be regarded as limiting the scope. For ordinary technicians in this field, other relevant drawings can be obtained based on these drawings without creative work.

[0037] FIG1 is a schematic structural diagram of a first multi-axis magnetic field sensor provided in an embodiment of the present application;

[0038] FIG2 is a schematic structural diagram of a second multi-axis magnetic field sensor provided in an embodiment of the present application;

[0039] FIG3 is a schematic diagram of a first magnetic flux path simulation provided by an embodiment of the present application;

[0040] FIG4 is a schematic diagram of a second magnetic flux path simulation provided by an embodiment of the present application;

[0041] FIG5 is a schematic structural diagram of a third multi-axis magnetic field sensor provided in an embodiment of the present application;

[0042] FIG6 is a schematic structural diagram of a fourth multi-axis magnetic field sensor provided in an embodiment of the present application;

[0043] FIG7 is a schematic structural diagram of a fifth multi-axis magnetic field sensor provided in an embodiment of the present application;

[0044] FIG8 is a schematic diagram of a third magnetic flux path simulation provided in an embodiment of the present application. DETAILED DESCRIPTION

[0045] The following embodiments of the technical solution of the present application will be described in detail with reference to the accompanying drawings. The following embodiments are only used to more clearly illustrate the technical solution of the present application and are therefore only examples and are not intended to limit the scope of protection of the present application.

[0046] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by those skilled in the art 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.

[0047] In the description of the embodiments of this application, the technical terms "first" and "second" are used only to distinguish different objects and should not be understood to indicate or imply relative importance or implicitly specify the quantity, specific order, or primary and secondary relationship of the indicated technical features. In the description of the embodiments of this application, the meaning of "plurality" is two or more, unless otherwise specifically defined.

[0048] FIG1 is a schematic diagram of the structure of the first multi-axis magnetic field sensor provided by an embodiment of the present application. Specifically, the upper portion of FIG1 shows 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, and the lower portion of FIG1 shows a schematic diagram of the projection structure of the multi-axis magnetic field sensor on the XZ plane (with the plane where the first substrate is located as the XY plane). FIG2 is a schematic diagram of the structure of the second multi-axis magnetic field sensor provided by an embodiment of the present application. Specifically, the upper portion of FIG2 shows a schematic diagram of the projection structure of the "components 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, the middle portion of FIG2 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, and the lower portion of FIG2 shows a schematic diagram of the projection structure of the multi-axis magnetic field sensor on the XZ plane (with the plane where the first substrate 1a or the second substrate 1b is located as the XY plane). The multi-axis magnetic field sensor includes:

[0049] At least one first magnetic conductor 2z1 disposed in a third direction on the first substrate 1a;

[0050] At least one second magnetic conductor 2z3 in the third direction is provided 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 conductive area of ​​the magnetic conductor; wherein the substrate is the first substrate 1a or the second substrate 1b, and the magnetic conductive area of ​​the magnetic conductor is the magnetic conductive area of ​​the first magnetic conductor 2z1 or the magnetic conductive area of ​​the second magnetic conductor 2z3;

[0051] A first air gap, wherein the first air gap is formed based on the first magnetic conductor 2z1 and the second magnetic conductor 2z3;

[0052] A third magnetic conductor 2x1 (may include 2x1a and 2x1b) in the second direction provided on the substrate (the first substrate 1a or the second substrate 1b) or the passivation layer 1c, the third magnetic conductor 2x1 having a second air gap;

[0053] A fourth magnetic conductor 2y1 (which may include 2y1a and 2y1b) is provided in a first direction on the substrate (the first substrate 1a or the second substrate 1b) or the 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;

[0054] At least three magnetic sensing units (at least one of 2x2a and 2x2c, at least one of 2y2a and 2y2b, and at least one of 2z2a, 2z2b, 2x2c, and 2z2d), each located within a corresponding air gap region; wherein the air gap regions include the air gap regions of the first air gap, the second air gap, and the third air gap; the sensor forms magnetic signal output circuits for measuring different magnetic induction intensity directions based on the magnetic sensing units; wherein the passivation layer 1c is a passivation protective layer surrounding the magnetic sensing units, and the magnetic sensing units within the same passivation layer have the same magnetic induction sensitivity direction. The "magnetic induction sensitivity direction of the magnetic sensing unit within 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 sensing unit within 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 sensing unit within 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.

[0055] Among them, the direction of the magnetic conductors (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 materials. The number of first air gaps can be one or more, and the number of second air gaps can also be one or more. This 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 conductor 2z1 and the second magnetic conductor 2z3. If the number of first magnetic conductors 2z1 is 1 and the number of second magnetic conductors 2z3 is 2, or if 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 conductor 2z1 and the second magnetic conductor 2z3. The magnetic induction unit can be a magnetoresistive film (MR), specifically, a giant magnetoresistance (GMR), a tunnel magnetoresistance (TMR), or anisotropic magnetoresistance (AMR). 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.

[0056] A first magnetic signal output circuit for detecting the magnetic induction intensity in a first direction can be formed based on the second magnetic induction unit (2y2a or 2y2b) and a resistor; the first magnetic signal output circuit can also be formed based on the second magnetic induction unit (2y2a or 2y2b) and an external magnetic field magnetic induction unit 2A, or 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 a second direction can be formed based on the first magnetic induction unit (2x2a or 2x2c) and a resistor; the second magnetic signal output circuit can also be formed based on the first magnetic induction unit (2x2a or 2x2c) and an external magnetic field magnetic induction unit 2A, or 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 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. The third direction refers to a direction perpendicular to the plane of the substrate (first substrate 1a or second substrate 1b). 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. The third magnetic signal output circuit can also be formed based on third magnetic induction units "2z2a and 2z2b," "2z2a and 2z2d," "2z2b and 2z2c," or "2z2c and 2z2d." The first, second, and third magnetic signal output circuits can be differential half-bridge or differential full-bridge output circuits.

[0057] Taking the first substrate 1a shown in Figure 1 as the XY plane, with the first direction being the Y-axis, the second direction being the X-axis, and the third direction being the Z-axis as an example, the left side is the X-axis magnetic field measurement area 2x, the middle is the Y-axis magnetic field measurement area 2y, and the right side is the Z-axis magnetic field measurement area 2z. The magnetic field measurement area 2z includes a first magnetic conductor 2z1 and a second magnetic conductor 2z3 made of a high-permeability metallic soft magnetic material. As shown in Figure 1, in this embodiment, the multi-axis magnetic field sensor includes three elongated strips of metallic soft magnetic material (first magnetic conductors 2z1) formed on the first substrate 1a by deposition and semiconductor micromachining for detecting magnetic induction intensity in the Z-axis direction. The multiple first magnetic conductors 2z1 are spaced apart in the X-axis direction. After the surfaces of the first magnetic conductors 2z1 are polished using a CMP chemical mechanical polishing process and a passivation layer is deposited, an MR magnetoresistive film is deposited on the passivation layer and semiconductor patterning micromachining is used to form the third magnetic sensing units (2z2a, 2z2b, 2z2c, and 2z2d). After a passivation layer is deposited again above the third magnetic sensing units (2z2a, 2z2b, 2z2c, and 2z2d) to protect the magnetoresistive film, two elongated strips of metal soft magnetic material (second magnetic conductors 2z3) are formed above the passivation layer through deposition and semiconductor micromachining to detect the magnetic induction intensity in the Z-axis direction. The multiple second magnetic conductors 2z3 are spaced apart in the X-axis direction. The MR magnetoresistive film used in the third magnetic sensing units can be a giant magnetoresistance (GMR). Figure 1 shows a case where 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 sensing units 2z2a, 2z2b, 2z2c, and 2z2d in the Z-axis direction (i.e., the projections of the third magnetic sensing units 2z2a, 2z2b, 2z2c, and 2z2d on the first substrate 1a) are located in the spaced-apart region between the metal soft magnetic materials of the first magnetic conductor 2z1 and the second magnetic conductor 2z3.

[0058] Specifically, let's take the example of a case where the direction of the external magnetic field is the positive Z-axis direction, and the magnetic induction sensitivity of the third magnetic sensing units 2z2a, 2z2b, 2z2c, and 2z2d is all in the positive X-axis direction. In this case, the direction of the converted X-axis magnetic field component at the locations of the third magnetic sensing units 2z2a and 2z2c is in the positive X-axis direction, and the direction at the locations of the third magnetic sensing units 2z2b and 2z2d is in the negative X-axis direction. Because the magnetic induction sensitivity of the third magnetic sensing units 2z2a, 2z2b, 2z2c, and 2z2d is all in the positive X-axis direction, the resistance values ​​of the third magnetic sensing units 2z2a and 2z2c decrease, while the resistance values ​​of the third magnetic sensing units 2z2b and 2z2d increase. Therefore, a push-pull full-bridge structure or a differential full-bridge structure with additional resistors can be used 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 conditioning signal) of the third magnetic signal output circuit for detecting the third direction (i.e., the Z-axis direction).

[0059] FIG3 is a schematic diagram of a first magnetic flux path simulation provided by an embodiment of the present application. Specifically, FIG3 is a magnetic flux path simulation diagram after applying a magnetic field to be measured in the positive direction of the Z axis in the magnetic field measurement area 2z in the Z-axis direction of the embodiment provided in FIG1. ​​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 spaced apart, 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 spaced distribution soft magnetic array vertical detection structure (i.e., magnetic field measurement area 2z) adopted in the present application solves the problem of uneven magnetic field distribution in the measurement direction of the long strip soft magnetic sheet arranged in a single-layer array, severe sensitivity loss, low precision, and high noise, enhances the magnetic field concentration effect and magnetic field uniformity, and has higher magnetic field conversion efficiency, improved sensitivity, improved the overall accuracy, sensitivity, and stability of the three-axis sensor, and reduced noise.

[0060] In some optional embodiments, the sensor further 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 forms a second magnetic signal output circuit for detecting the magnetic induction intensity in the second direction 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).

[0061] If the external magnetic field is directed in the positive direction of the X-axis, the magnetic field to be measured is concentrated and amplified by the metallic soft magnetic material structure (third magnetic conductor 2x1) to form a magnetic circuit. The first magnetic sensing unit (2x2a or 2x2c) detects the magnetic field along the positive direction of the X-axis, which is concentrated and amplified at the second air gap of the metallic soft magnetic material structure (third magnetic conductor 2x1). The first magnetic shielding magnetic sensing unit (2x2b or 2x2d) detects the magnetic field that has been shielded and weakened by the metallic soft magnetic material structure (third magnetic conductor 2x1). As a result, the resistance of the first magnetic sensing unit (2x2a or 2x2c) decreases, while the resistance of the first magnetic shielding magnetic sensing unit (2x2b or 2x2d) remains approximately unchanged. A differential full-bridge or differential half-bridge structure can be used to sense the magnetic field in the X-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 a 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. After the generated differential voltage signal is amplified by the closed-loop signal conditioning circuit, a feedback magnetic field is generated by the magnetic field feedback coil to achieve dynamic magnetic field balance. 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).

[0062] In some optional embodiments, the fourth magnetic conductor 2y1 (2y1a and 2y1b, Figure 2 takes only 2y1b as an example to show the various parts included in the fourth magnetic conductor 2y1b) 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; 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.

[0063] 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.

[0064] 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 circuits 2yc1 and fourth conversion magnetic circuits 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 areas of the third conversion air gap and the fourth conversion air gap.

[0065] The magnetic field measurement area 2y includes a fourth magnetic conductor 2y1 made of a high-permeability metallic soft magnetic material. As shown in Figure 1, in this embodiment, the Y-axis magnetic field measurement area 2y of the multi-axis magnetic field sensor comprises a fourth magnetic field input area 2ya located at both ends of the fourth magnetic conductor 2y1, oriented in the first direction, and a fourth magnetic field conversion area 2yb located between the ends of the fourth magnetic conductor 2y1. The fourth magnetic field conversion area 2yb includes a fourth magnetic field conversion circuit 2yc located in the second direction; the fourth magnetic field conversion circuit 2yc has the third air gap. The fourth magnetic conductor 2y1 can concentrate the magnetic flux of the input magnetic field in the detection direction and then distort the magnetic circuit at the corners, generating a magnetic field component perpendicular to the input magnetic field.

[0066] The following description will be made using an example where the direction of the external magnetic field is the positive direction of the Y axis, and the magnetic induction sensitivity directions of the second magnetic induction units (2y2a, 2y2b) are both in the positive direction of the X axis. At this point, the magnetic circuit conversion zone located at the negative Y axis end of the metal soft magnetic material structure 2y1 concentrates the magnetic flux of the magnetic field to be measured in the positive Y axis direction, then distorts the magnetic circuit at the corner, and generates a magnetic field in the positive X axis direction at the fourth conversion air gap of the fourth conversion magnetic circuit 2yc2. Thereafter, 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 X axis direction to the negative X axis direction, and generates a magnetic field in the negative X axis direction at the third conversion air gap of the third conversion magnetic circuit 2yc1. Finally, the magnetic circuit is distorted back to the positive Y axis direction by the magnetic circuit conversion zone containing an L-shaped corner at the positive Y axis end of the metal soft magnetic material structure 2y1, thereby achieving symmetry in the measurement of magnetic fields in the positive and negative Y axis directions. 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 using the same magnetoresistive thin film deposition process.

[0067] FIG4 is a schematic diagram of a second magnetic flux path simulation provided in an embodiment of the present application. Specifically, FIG4 is a magnetic flux path simulation diagram after the magnetic field measurement area 2y in the Y-axis direction in the embodiment provided in FIG1 is applied with the Y-axis positive direction magnetic field to be measured. 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 Y-axis positive direction magnetic field to be measured, and generates obvious components opposite to the X-axis direction 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, amplify, temperature compensate, and linearize the generated differential voltage signal to form an output signal (first conditioned signal) of a first magnetic signal output circuit for detecting a 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. After the generated differential voltage signal is amplified by the closed-loop signal conditioning circuit, a feedback magnetic field is generated by the magnetic field feedback coil to achieve dynamic magnetic field equilibrium. 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 a first direction (i.e., the Y-axis direction). The magnetic field feedback coil is a coil that is wound along the XY plane on the second substrate 1b.

[0068] In the specific embodiment of the multi-axis magnetic field sensor corresponding to Figure 1, 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.

[0069] 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, solving the "technical problem that the existing three-axis magnetic field sensor has poor accuracy and is difficult to achieve single-chip integrated manufacturing."

[0070] As shown in Figure 2, this multi-axis magnetic field sensor is implemented based on a dual-substrate, trenchless structure. In this embodiment, the X-axis magnetic field measurement area 2x utilizes metallic soft magnetic material structures 2x1a and 2x1b, which are symmetrically distributed about the XY plane on the first substrate 1a and the second substrate 1b. The Y-axis magnetic field measurement area 2y utilizes metallic soft magnetic material structures 2y1a and 2y1b, which are symmetrically distributed about the XY plane on the first substrate 1a and the second substrate 1b. This multi-axis magnetic field sensor includes three elongated strips of metallic soft magnetic material (first magnetic conductors 2z1) formed on the first substrate 1a through deposition and semiconductor micromachining for detecting magnetic induction intensity in the Z-axis direction. These first magnetic conductors 2z1 are spaced apart in the X-axis direction. After the surfaces of the first magnetic conductors 2z1 are polished using a CMP chemical mechanical polishing process and a passivation layer is deposited, an MR magnetoresistive film is deposited on the passivation layer and semiconductor patterning micromachining is used to form the third magnetic sensing units (2z2a, 2z2b, 2x2c, and 2z2d). After a passivation layer is deposited again above the third magnetic sensing units (2z2a, 2z2b, 2x2c, and 2z2d) to protect the magnetoresistive film, two elongated strips of metal soft magnetic material (second magnetizers 2z3) are formed above the passivation layer through deposition and semiconductor micromachining to detect the magnetic induction intensity in the Z-axis direction. Multiple second magnetizers 2z3 are spaced apart in the X-axis direction. The MR magnetoresistive film used in the third magnetic sensing unit can be a tunnel magnetoresistive (TMR) film. Using a single chip packaging process, WLP wafer-level advanced packaging and TSV through-silicon via (TSV) technology are used to attach lead pads, circuitry, and a mechanical support housing. The first substrate 1a and the second substrate 1b are packaged with the tunnel magnetoresistive (TMR) surfaces facing each other. Figure 2 shows a situation where the projections of the first magnetizer 2z1 and the second magnetizer 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 spaced distribution areas of the metallic soft magnetic materials of the first magnetic conductor 2z1 and the second magnetic conductor 2z3.

[0071] 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.

[0072] Figure 5 is a schematic diagram of the structure of the third multi-axis magnetic field sensor provided in an embodiment of the present application. Specifically, the upper portion of Figure 5 shows a schematic diagram of the projection structure of the "components between the passivation layer 1c2 and the second substrate 1b" of the multi-axis magnetic field sensor on the plane (XY plane) where the second substrate 1b lies. The middle portion of Figure 5 shows a schematic diagram of the projection structure of the "components between the passivation layer 1c1 and the first substrate 1a" of the multi-axis magnetic field sensor on the plane (XY plane) where the first substrate 1a lies. The lower portion of Figure 5 shows a schematic diagram of the projection structure of the multi-axis magnetic field sensor on the XZ plane (with the plane where the first substrate 1a or the second substrate 1b lies as the XY plane).

[0073] This embodiment uses two substrates, namely a first substrate 1a and a second substrate 1b located in the XY plane. The magnetic field measurement area 2z in the Z-axis direction senses the magnetic field to be measured in the Z-axis direction, 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. As shown in Figure 5, the first magnetic conductor 2z1 is disposed on the first substrate 1a; the second magnetic conductor 2z3 is disposed on the second substrate 1b; the third magnetic conductor 2x1 includes 2x1a and 2x1b, where 2x1a is disposed on the first substrate 1a and 2x1b is disposed on the second substrate 1b; and the fourth magnetic conductor 2y1 is disposed on the second substrate 1b.

[0074] For the magnetic field measurement region 2z in the Z-axis direction, as shown in the XZ cross-section in Figure 5, MR magnetoresistive films employing tunnel magnetoresistance (TMR) are deposited on the surfaces of the first substrate 1a and the second substrate 1b. Semiconductor patterning and micromachining are then used to form the third magnetic sensing units 2z2a and 2z2b, respectively. A passivation layer is then deposited to protect the magnetoresistive films. A reverse-surface deep reactive ion etching (DRIE) process is used to form trenches on the sides of the first and second substrates 1a and 1b facing away from the MR magnetoresistive films. A soft magnetic metal material is deposited within the trenches and polished using chemical mechanical polishing (CMP). This forms the first magnetic conductor 2z1 in the first substrate 1a, and the second magnetic conductor 2z3 in the second substrate 1b. A single chip packaging process is adopted, and lead pads, circuits, and mechanical support housings are added through the 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 magnetoresistors TMR are located facing each other, so that the sensitivity directions of the packaged third magnetic induction units 2z2a and 2z2b are opposite, namely the positive direction of the X-axis and the negative direction of the X-axis, respectively. As shown in FIG5 , the metal soft magnetic materials in the first magnetic conductor 2z1 and the second magnetic conductor 2z3 are distributed at intervals 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 area where the metal soft magnetic materials of the first magnetic conductor 2z1 and the second magnetic conductor 2z3 are distributed at intervals. It should be noted that, because the sensitivity of the third magnetic sensing units 2z2a and 2z2b is in opposite directions after packaging, in this embodiment, only a single groove is etched in each of the first substrate 1a and the second substrate 1b. That is, the first magnetic conductor 2z1 and the second magnetic conductor 2z3 each utilize a single strip of soft magnetic metal material. In practical applications, more than one spaced groove can be etched as needed. Since the reverse DRIE process is primarily used to enhance magnetic concentration and improve sensitivity, its measurement principle is essentially the same as in the previous embodiment and will not be explained in detail here.

[0075] Specifically, let's take the example of a magnetic field to be measured in the positive Z-axis direction, with the sensitivity of third magnetic sensing unit 2z2a in the positive X-axis direction and that of magnetic sensing unit 2z2b in the negative X-axis direction. In this case, the converted X-axis magnetic field components at the locations of third magnetic sensing units 2z2a and 2z2b are both in the positive X-axis direction, resulting in a decrease in the resistance of third magnetic sensing unit 2z2a and an increase in the resistance of third magnetic sensing unit 2z2b. 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, amplify, temperature compensate, and perform linearity correction on the generated differential voltage signal to form an output signal (first conditioned signal) of a third magnetic signal output circuit for detecting a 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. After the generated differential voltage signal is amplified by the closed-loop signal conditioning circuit, a feedback magnetic field is generated by the magnetic field feedback coil to achieve dynamic magnetic field equilibrium. 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 is wound along the XY plane on the second substrate 1b.

[0076] For the X-axis magnetic field measurement region 2x, MR magnetoresistive thin films are deposited on the surfaces of the first substrate 1a and the second substrate 1b, respectively, and semiconductor patterning and micromachining are used to form the first magnetic sensing units 2x2a and 2x2c. A passivation layer is then deposited to protect the magnetoresistive films. As shown in Figure 5, alternately spaced trenches are etched on the first substrate 1a and the second substrate 1b, respectively. High-permeability metallic soft magnetic material is deposited in the trenches to form alternately spaced elongated strips of metallic soft magnetic material structures 2x1a and 2x1b. After packaging, the metallic soft magnetic material structures 2x1a and 2x1b are symmetrically distributed within the first substrate 1a and the second substrate 1b about the XY plane. The first magnetic sensing unit 2x2a and the third magnetic sensing unit 2z2a are located on the same layer and utilize the same magnetoresistive film deposition process, with both units exhibiting sensitivity in the positive X-axis direction. The first magnetic sensing unit 2x2c and the third magnetic sensing unit 2z2b are located on the same layer and utilize the same magnetoresistive film deposition process, with both units exhibiting sensitivity in the negative X-axis direction. The projections of the first magnetic sensing units 2x2a and 2x2c along the Z-axis lie within the air gaps between the metallic soft magnetic material distribution areas. For example, if the magnetic field to be measured is in the positive X-axis direction, the magnetic fields at both first magnetic sensing units 2x2a and 2x2c are in the positive X-axis direction. The resistance of the first magnetic sensing unit 2x2a decreases, while the resistance of the first magnetic sensing unit 2x2c increases. A push-pull full-bridge or push-pull half-bridge structure can be used to sense the magnetic field in the X-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 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 "first magnetic induction units 2x2a and 2x2c" 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 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 second magnetic signal output circuit for detecting the second direction.

[0077] For the Y-axis magnetic field measurement area 2y, the same magnetoresistive film deposition process as the third magnetic sensing unit 2z2b is used on the surface of the second substrate 1b to form the second magnetic sensing units 2y2a and 2y2b on the same layer. A passivation layer is then deposited to protect the magnetoresistive film. After packaging, the sensitivity of the second magnetic sensing units 2y2a and 2y2b is directed in the negative direction of the X-axis. As shown in Figure 5, a metal soft magnetic material structure 2y1 is formed by etching grooves in the second substrate 1b and depositing a high-permeability metallic soft magnetic material in the grooves. The shape of the metal soft magnetic material structure 2y1 in this embodiment is identical to the metal soft magnetic material structure 2y1 in the "Y-axis magnetic field measurement area 2y" in the embodiment corresponding to Figure 1. The main difference is that the metal soft magnetic material in the embodiment corresponding to Figure 1 is deposited above the second substrate 1b, while in this embodiment, the metal soft magnetic material is deposited within the grooves within the second substrate 1b. The projections of the second magnetic sensing units 2y2a and 2y2b along the Z-axis are located within the air gap of the metal soft magnetic material structure 2y1. For example, let's take the magnetic field to be measured in the positive direction of the Y-axis as an example. In this case, the resistance of second magnetic sensing unit 2y2a decreases, while the resistance of second magnetic sensing unit 2y2b increases. Therefore, a differential full-bridge structure can be formed by connecting second magnetic sensing units 2y2a and 2y2b in series and parallel with a reference resistor 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 the closed-loop signal conditioning circuit, and a feedback magnetic field is generated by the 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.

[0078] In summary, the multi-axis magnetic field sensor in the embodiment provided in FIG5 adopts a single chip packaging process on two substrates (the first substrate 1a and the second substrate 1b). 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 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, thereby improving 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 uses a reverse DRIE deep reactive ion etching process to form grooves, which can enhance the magnetic field concentration effect and improve sensitivity, solving the problems of low magnetic field conversion efficiency, sensitivity loss, and high noise in the measurement direction of the magnetic flux concentration structure in the prior art.

[0079] FIG6 is a schematic diagram of the structure of the fourth multi-axis magnetic field sensor provided in an embodiment of the present application. Specifically, the upper portion of FIG6 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. The middle portion of FIG6 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. The lower portion of FIG6 shows a schematic diagram of the projection structure of the multi-axis magnetic field sensor on the XZ plane (with the plane where the first substrate 1a or the second substrate 1b is located as the XY plane).

[0080] In some optional embodiments, 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 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 second air gap area and the second magnetically shielded magnetic induction unit.

[0081] This embodiment utilizes two substrates: a first substrate 1a and a second substrate 1b located in the XY plane. A magnetic field measurement area 2z, oriented in the Z-axis direction, senses the magnetic field to be measured in the Z-axis direction. A magnetic field measurement area 2x, oriented in the X-axis direction, senses the magnetic field to be measured in the X-axis direction. A magnetic field measurement area 2y, oriented in the Y-axis direction, senses the magnetic field to be measured in the Y-axis direction. As shown in Figure 6, a first magnetic conductor 2z1 is disposed on the first substrate 1a, while a second magnetic conductor 2z3, a third magnetic conductor 2x1, and a fourth magnetic conductor 2y1 are disposed on the passivation layer.

[0082] For the magnetic field measurement region 2z in the Z-axis direction, as shown in the XZ cross-section in Figure 6 , trenches spaced apart in the X-axis direction are etched on the first substrate 1a. High-permeability soft magnetic material is deposited in the trenches to form long, spaced-apart strips of soft magnetic material. These strips are then polished using a chemical mechanical polishing (CMP) process to form the first magnetic conductor 2z1. A magnetoresistive (MR) film employing tunnel magnetoresistance (TMR) is deposited above the first magnetic conductor 2z1. Semiconductor patterning and micromachining are then used to form the third magnetic sensing units 2z2a, 2z2b, 2z2c, and 2z2d. A passivation layer is then deposited to protect the magnetoresistive film. A further layer of soft magnetic material is deposited above the passivation layer, and semiconductor micromachining is used to form another layer of spaced-apart strips of soft magnetic material spaced apart from the first magnetic conductor 2z1 in the X-axis direction, forming the second magnetic conductor 2z3. As shown in Figure 6, 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 (that is, 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 conductive area of ​​the magnetic conductor (the magnetic conductive area of ​​the first magnetic conductor 2z1 or the second magnetic conductor 2z3).

[0083] Specifically, the sensitivity direction of the third magnetic sensing units 2z2a, 2z2b, 2z2c, and 2z2d is in the positive X-axis direction. For example, the magnetic field to be measured is in the positive Z-axis direction. In this case, the converted X-axis magnetic field components are both in the positive X-axis direction at the locations of the third magnetic sensing units 2z2a and 2z2c, and in the negative X-axis direction at the locations of the third magnetic sensing units 2z2b and 2z2d. The resistance values ​​of the third magnetic sensing units 2z2a and 2z2c decrease, while the resistance values ​​of the third magnetic sensing 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 and generate a differential voltage signal. Furthermore, an open-loop signal conditioning circuit can be used to condition, amplify, temperature compensate, and perform linearity correction on the generated differential voltage signal to form the output signal (first conditioned signal) of the second magnetic signal output circuit for detecting the second direction (i.e., the X-axis direction).

[0084] For the magnetic field measurement region 2x in the X-axis direction, a magnetoresistive (MR) film is deposited on the surface of the first substrate 1a and semiconductor patterning and micromachining is used to form the first magnetic sensing units (2x2a, 2x2c) and the first magnetic shielding magnetic sensing units (2x2b, 2x2d). A passivation layer is then deposited to protect the magnetoresistive film. The first magnetic sensing unit, the first magnetic shielding magnetic sensing unit, and the third magnetic sensing units (2z2a, 2z2b, 2z2c, 2z2d) are located on the same layer and utilize the same magnetoresistive film deposition process. Their sensitivity is all directed in the positive X-axis direction. As shown in Figure 6, the third magnetic conductor 2x1 and the second magnetic conductor 2z3 are located on the same layer and utilize the same deposition process. Deposition and semiconductor micromachining form spaced-apart strips above the magnetoresistive thin film passivation layer. The projections of the first magnetic sensing units 2x2a and 2x2c along the Z-axis lie within the air gaps between the spaced-apart metal soft magnetic material regions, while the projections of the first magnetic shielding magnetic sensing units 2x2b and 2x2d along the Z-axis lie within the projection coverage of the metal soft magnetic material. For example, when the magnetic field to be measured lies in the positive X-axis direction, the resistance of the first magnetic sensing units 2x2a and 2x2c decreases, while the resistance of the first magnetic shielding magnetic sensing units 2x2b and 2x2d remains approximately unchanged. This allows a differential full-bridge structure to sense the magnetic field in the X-axis direction and generate a differential voltage signal.

[0085] For the Y-axis magnetic field measurement area 2y, the second magnetic induction units (2y2a, 2y2b), the second magnetic shielding magnetic induction units (2y2c, 2y2d), and the fourth magnetic conductor 2y1 are formed using the same process. 2y2 represents the magnetic induction units in the Y-axis magnetic field measurement area 2y (in this embodiment, including the second magnetic induction units 2y2a, 2y2b and the second magnetic shielding magnetic induction units 2y2c, 2y2d). It should be noted that when a single chip packaging process is used, using WLP wafer-level advanced packaging and TSV through-silicon via technology to attach lead pads, circuits, and a mechanical support housing, the first substrate 1a and the second substrate 1b are packaged with the tunnel magnetoresistors (TMR) facing each other. The magnetic induction sensitivity of the packaged second magnetic induction units must be perpendicular to that of the first or third magnetic induction units. In this embodiment, as shown in FIG6 , the magnetic induction sensitivity of the second magnetic induction units is in the negative Y-axis direction, while the magnetic induction sensitivity of the first or third magnetic induction units is in the positive X-axis direction.

[0086] In summary, the multi-axis magnetic field sensor provided in this embodiment adopts a single chip packaging process on two substrates 1. 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.

[0087] FIG7 is a schematic diagram of the structure of the fifth multi-axis magnetic field sensor provided in an embodiment of the present application. Specifically, the upper portion of FIG7 shows a schematic diagram of the projection structure of the "first magnetic sensing unit, the first magnetic shielding magnetic sensing unit, and the fourth magnetic conductor" of the multi-axis magnetic field sensor on the plane (XY plane) where the first substrate 1a is located. The middle portion of FIG7 shows a schematic diagram of the projection structure of the "second magnetic sensing unit, the second magnetic shielding magnetic sensing unit, the third magnetic sensing unit, the first magnetic conductor, the second magnetic conductor, and the third magnetic conductor" of the multi-axis magnetic field sensor on the plane (XY plane) where the second substrate 1b is located. The lower portion of FIG7 shows a schematic diagram of the projection structure of the multi-axis magnetic field sensor on the XZ plane (with the plane where the first substrate 1a or the second substrate 1b is located as the XY plane). Reference numeral 2y2 represents the magnetic sensing units (in this embodiment, including second magnetic sensing units 2y2a and 2y2b) in the magnetic field measurement area 2y in the Y-axis direction.

[0088] In some optional embodiments, the third magnetic conductor 2x1 includes: a third magnetic field input region in the second direction located at both ends of the third magnetic conductor 2x1 and a third magnetic field conversion region located between the two ends of the third magnetic conductor; the third magnetic field conversion region 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.

[0089] 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.

[0090] This embodiment utilizes two substrates: a first substrate 1a and a second substrate 1b located in the XY plane. A magnetic field measurement area 2z, oriented in the Z-axis direction, senses the magnetic field to be measured in the Z-axis direction. A magnetic field measurement area 2x, oriented in the X-axis direction, senses the magnetic field to be measured in the X-axis direction. A magnetic field measurement area 2y, oriented in the Y-axis direction, senses the magnetic field to be measured in the Y-axis direction. As shown in Figure 7, a first magnetic conductor 2z1 is disposed on the first substrate 1a, while a second magnetic conductor 2z3, a third magnetic conductor 2x1, and a fourth magnetic conductor 2y1 are disposed on the passivation layer.

[0091] For the magnetic field measurement region 2x in the X-axis direction, a magnetoresistive (MR) thin film employing anisotropic magnetoresistance (AMR) is deposited on the surface of the first substrate 1a and processed through semiconductor micromachining to form the first magnetic sensing units (2x2a, 2x2c). In this embodiment, the magnetic sensitivity of the first magnetic sensing units (2x2a, 2x2c) located on the first substrate 1a is directed in the negative Y-axis direction. A passivation layer is then deposited to protect the magnetoresistive film. A metal soft magnetic material is further deposited above the passivation layer, and semiconductor micromachining is used to form the third magnetic conductor 2x1. In this embodiment, the third magnetic conductor 2x1 comprises a magnetic circuit conversion region of metal soft magnetic material with a corner. Its shape is similar to the combination of the shapes of the fourth magnetic conductor 2y1 in the embodiment corresponding to FIG2 . Specifically, as shown in the XY cross-section in FIG7 , the metal soft magnetic material structure 2x1 comprises two metal soft magnetic material structures parallel to the XY plane and symmetrical about the X-axis, thereby forming two symmetrical magnetic flux paths in parallel. For the metallic soft magnetic material structure 2x1 in the positive Y-axis direction, using the example of a magnetic field to be measured in the positive X-axis direction, the magnetic circuit conversion region containing an L-shaped corner at the negative X-axis end of the metallic soft magnetic material structure 2x1 concentrates the magnetic flux of the magnetic field to be measured in the positive X-axis direction and then distorts the magnetic circuit at the corner, generating a magnetic field in the positive Y-axis direction that passes through the air gap where the Z-axis projection of the first magnetic sensing unit 2x2a is located. The metallic soft magnetic material structure 2x1 then uses the magnetic circuit conversion region containing a U-shaped corner to distort the magnetic circuit in the positive Y-axis direction to the negative Y-axis direction, passing through the air gap where the Z-axis projection of the second magnetic sensing unit 2x2c is located. Finally, the magnetic circuit conversion region containing an L-shaped corner at the positive X-axis end of the metallic soft magnetic material structure 2x1 distorts the magnetic circuit back to the positive X-axis direction, achieving symmetry in the measurement of magnetic fields in the positive and negative X-axis directions. Therefore, the metallic soft magnetic material structures in the positive Y-axis direction of the metallic soft magnetic material structure 2x1 are connected in series to the same magnetic circuit. The metal soft magnetic material structure of the negative half of the Y-axis in the metal soft magnetic material structure 2x1 and the metal soft magnetic material structure of the positive half of the Y-axis are symmetrical about the X-axis. That is, after the magnetic field to be measured in the positive X-axis direction is distorted by the magnetic circuit conversion zone, the magnetic circuit is oriented in the positive Y-axis direction at the air gap where the Z-axis projection of the first magnetic induction unit 2x2a is located, and the magnetic circuit is oriented in the negative Y-axis direction 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 the positive half of the Y-axis in the metal soft magnetic material structure 2x1 is connected in series to the same magnetic circuit. Therefore, in this embodiment, the two magnetic circuits formed by the metal soft magnetic material of the positive half and negative half of the Y-axis in the metal soft magnetic material structure 2x1 are connected in parallel.

[0092] FIG8 is a schematic diagram of a third magnetic flux path simulation provided in an embodiment of the present application. Specifically, FIG8 is a magnetic flux path simulation diagram after the magnetic field to be measured in the positive direction of the X-axis is applied to the magnetic field measurement area 2x in the X-axis direction in the embodiment provided in FIG7 . 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.

[0093] The Y-axis magnetic field measurement area 2y utilizes a similar measurement principle to the X-axis magnetic field measurement area 2x, and shares some metallic soft magnetic material with the Z-axis magnetic field measurement area 2z. Specifically, for the Y-axis magnetic field measurement area 2y, an MR magnetoresistive film is deposited on the surface of the second substrate 1b and processed through semiconductor patterning micromachining, as shown in the XY cross-section in Figure 7. This forms a second magnetic sensing unit (2y2a, 2y2b) with a sensitivity direction in the positive X-axis direction. A passivation layer is then deposited to protect the magnetoresistive film. A metallic soft magnetic material is further deposited above the passivation layer, and semiconductor micromachining is used to form a fourth magnetic conductor 2y1. The second magnetic sensing units (2y2a, 2y2b) form a push-pull full-bridge structure to sense the magnetic field in the Y-axis direction, generating a differential voltage signal.

[0094] For the magnetic field measurement area 2z in the Z-axis direction, the third magnetic sensing units (2z2a, 2z2b) and the second magnetic sensing units (2y2a, 2y2b) are located on the same layer and utilize the same magnetoresistive film deposition process. As shown in FIG7 , magnetic sensing units 2z2a and 2z2b are formed, each with its sensitivity oriented in the positive X-axis direction. A passivation layer is then 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 metallic soft magnetic material. Specifically, the metallic soft magnetic material located at the positive X-axis end of the metallic soft magnetic material structure 2y1 in FIG7 also serves as the metallic soft magnetic material located at the negative X-axis end of the second magnetic conductor 2z3. Therefore, for the magnetic field measurement region 2z of this embodiment, after forming the third magnetic sensing units 2z2a and 2z2b protected by the passivation layer, as shown in Figure 7, a groove is etched on the second substrate 1b at a location spaced apart in the positive direction of the X-axis, sharing the metal soft magnetic material with the aforementioned components. High-permeability metal soft magnetic material is deposited in the groove to form a long strip of metal soft magnetic material, which constitutes the first magnetic conductor 2z1. The second magnetic conductor 2z3 is located on the same layer as the metal soft magnetic material structure 2y1 and uses the same deposition and semiconductor micromachining processes. In addition to containing the metal soft magnetic material shared by the aforementioned components, it also includes another long strip of metal soft magnetic material, spaced apart from the first magnetic conductor 2z1 in the positive direction of the X-axis, located above the magnetoresistive film passivation layer. 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 aforementioned part; the projection of the third magnetic induction unit 2z2b in the Z-axis direction is located at the gap between another long strip of metal soft magnetic material between the first magnetic conductor 2z1 and the second magnetic conductor 2z3.

[0095] Specifically, the sensitivity direction of the third magnetic sensing units 2z2a and 2z2b is in the positive X-axis direction. For example, the magnetic field to be measured is in the positive Z-axis direction. In this case, the converted X-axis magnetic field component is in the positive X-axis direction at the location of the third magnetic sensing unit 2z2a, and in the negative X-axis direction at the location of the third magnetic sensing unit 2z2b. Therefore, a push-pull half-bridge structure can be used to sense the magnetic field in the Z-axis direction and generate a differential voltage signal. It is important to note that in this embodiment, when a single chip packaging process is used, using WLP wafer-level advanced packaging and TSV through-silicon via (TSV) technology to attach lead pads, circuits, and a mechanical support housing to package the first substrate 1a and the second substrate 1b with the MR magnetoresistive film surfaces facing each other, the magnetic sensitivity directions of the packaged first magnetic sensing unit and the "second or third magnetic sensing unit" must be perpendicular to each other. In this embodiment, as shown in FIG7 , the magnetic sensitivity direction of the first magnetic sensing unit is in the negative Y-axis direction, while the magnetic sensitivity direction of the second or third magnetic sensing unit is in the positive X-axis direction.

[0096] In summary, the multi-axis magnetic field sensor provided in this embodiment utilizes a single chip packaging process on two substrates 1, similar to the embodiment corresponding to FIG6 . Its characteristic is that, during packaging, the sensitivity directions of the magnetic sensing units on the first substrate 1a and the second substrate 1b are perpendicular, 90 degrees apart in the XY plane. However, the metal soft magnetic material structures 2x1 and 2y1 in this embodiment each utilize two magnetic circuits parallel to the XY plane and symmetrical about the X or Y axis, forming a push-pull full-bridge structure. This advantage is that only a single magnetic sensing unit with the same sensitivity direction is prepared on each substrate, enabling push-pull bridge measurement on all three axes, X, Y, and Z. Compared to a conventional differential full-bridge structure in which some resistance varies with the magnetic field and some resistance remains approximately constant, this embodiment exhibits higher sensitivity, better consistency, and higher accuracy. Furthermore, different detection modules in this embodiment directly share some of the metal soft magnetic material, which helps save costs and reduce size.

[0097] 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 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 2A.

[0098] 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.

[0099] 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 magnetic induction intensity directions based on the magnetic induction unit and the resistor.

[0100] 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 technology.

[0101] It should be understood that the multi-axis magnetic field sensor chip corresponds to the embodiment of the multi-axis magnetic field sensor described above. The specific functional implementation of the multi-axis magnetic field sensor chip can be found in the specific description of the multi-axis magnetic field sensor above. To avoid repetition, the detailed description is appropriately omitted here.

[0102] The functional modules in each embodiment of the present application can be integrated together to form an independent part, or each module can exist independently, or two or more modules can be integrated to form an independent part.

[0103] The above description is only an optional implementation method of the embodiment of the present application, but the protection scope of the embodiment of the present application is not limited to this. Any technician familiar with this technical field can easily think of changes or replacements within the technical scope disclosed in the embodiment of the present application, and they should all be covered by the protection scope of the embodiment 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 1, 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 is formed based on the third conversion magnetic induction unit and the fourth conversion magnetic induction unit to detect the first direction A first magnetic signal output circuit of a magnetic induction intensity of a first magnetic signal; wherein the third conversion magnetic induction unit and the fourth conversion magnetic induction unit are respectively located in the air gap area 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 1, 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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