Z-axis magnetic field sensor and processing method therefor

Abstract

The present application relates to the technical field of magnetic field measurement, and provides a Z-axis magnetic field sensor and a processing method therefor. The sensor comprises a substrate, a magnetic flux conversion module, a magnetic induction module, and an output module; a metal soft magnetic material having a high magnetic conductivity that forms the magnetic flux conversion module is located in a groove formed by etching in the substrate or located above the substrate, and the magnetic flux conversion module comprises a first magnetic flux conversion unit and a second magnetic flux conversion unit; the first magnetic flux conversion unit and the second magnetic flux conversion unit comprise metal the soft magnetic materials spaced apart from each other, which concentrate and amplify a magnetic field to be measured in a Z-axis direction and then convert the magnetic field direction, thus generating an X-axis magnetic field component; the magnetic induction module induces the magnetic field of the magnetic flux conversion module and generates a differential voltage signal, and by means of the output module, an output signal of the magnetic field to be measured is formed. The Z-axis magnetic field sensor and processing method provided in the present application have the characteristics of high magnetic field conversion efficiency, a uniform magnetic field distribution, high sensitivity, good stability, low noise, and available single-chip and small-size manufacturing.

Description

Z-axis magnetic field sensor and its processing and preparation method Technical Field

[0001] The present invention relates to the field of magnetic field measurement technology, and in particular to a Z-axis magnetic field sensor and a processing and manufacturing method thereof. Background Art

[0002] Magnetic sensors are widely used in modern industry and electronic products. They can measure physical parameters such as current, position, motion, and direction by sensing changes in magnetic field strength. This process usually involves measuring the Z-axis magnetic field, that is, measuring the magnetic field in the normal direction of the plane where the magnetic sensor is located.

[0003] Currently, Z-axis magnetic field measurement is primarily achieved through detection coils, Hall elements, or magnetoresistive elements. Detection coils have low spatial resolution, limited sensitivity, and limited frequency characteristics; Hall elements have low sensitivity, high power consumption, and poor temperature characteristics; and magnetoresistive elements are generally sensitive in-plane, limiting their application in applications such as perpendicular magnetic fields and three-axis vector magnetic field detection.

[0004] Summary of the Invention

[0005] In order to achieve better vertical magnetic field detection, the present invention provides a Z-axis magnetic field sensor and a processing method thereof to solve the problems of low sensitivity, poor accuracy, and high noise of existing Z-axis magnetic field sensors.

[0006] In a first aspect, the present application provides a Z-axis magnetic field sensor, comprising: a substrate, a magnetic flux conversion module, a magnetic induction module, and an output module. The magnetic flux conversion module is disposed within a groove of the substrate or above the substrate; the magnetic flux conversion module is configured to modulate the magnetic field to be measured, generating a magnetic field component in the X-axis direction to form a target magnetic flux path; wherein the direction of the magnetic field to be measured is the Z-axis direction. The magnetic induction module includes at least two magnetic induction units, each of which is disposed between the magnetic flux conversion modules along the Z-axis direction. The magnetic induction units are configured to generate a differential voltage signal under the action of the target magnetic flux path; wherein the magnetic induction units are composed of at least one magnetoresistive sensitive element, and the sensitivity directions of the magnetic induction units are the same; the magnetic induction module uses at least one structure selected from the group consisting of a differential full-bridge, a differential half-bridge, a push-pull full-bridge, and a push-pull half-bridge to sense the magnetic field of the magnetic flux conversion module, generate a differential voltage signal, and form an output signal of the magnetic field to be measured through the output module. wherein the plane in which the substrate is located is the plane formed by the X-axis and the Y-axis, the magnetic flux conversion module is disposed along the X-axis direction, and the plane perpendicular to the plane in which the substrate is located is the plane in which the Z-axis is located.

[0007] Optionally, the magnetic flux conversion module includes at least one first magnetic flux conversion unit and at least one second magnetic flux conversion unit; the first magnetic flux conversion unit and the second magnetic flux conversion unit are arranged on both sides of the magnetic induction unit along the Z-axis direction; the first magnetic flux conversion unit and the second magnetic flux conversion unit are used to concentrate and amplify the magnetic field to be measured to form a target magnetic flux path, and generate a magnetic field component in the X-axis direction at the interval position between the first magnetic flux conversion unit and the second magnetic flux conversion unit; wherein the projections of the first magnetic flux conversion unit and the second magnetic flux conversion unit on the X-axis do not overlap or the overlapping part is less than the overlapping threshold; the overlapping threshold is related to the measurement range of the magnetic field sensor.

[0008] Optionally, the substrate includes a first substrate and a second substrate. The metallic soft magnetic materials of the first magnetic flux conversion unit and the second magnetic flux conversion unit are respectively located inside the grooves of the first substrate and the second substrate; and the magnetic induction unit is located between the first substrate and the second substrate.

[0009] Furthermore, when the magnetic induction unit is located in a plane formed by different X-axis and Y-axis in the Z-axis direction, the first plane includes at least one magnetic induction unit and the second plane includes at least one magnetic induction unit; the first plane magnetic induction unit is integrated on the first substrate and the second plane magnetic induction unit is integrated on the second substrate; the sensitivity directions of the first plane magnetic induction unit and the second plane magnetic induction unit are the same or different.

[0010] Optionally, the magnetic flux conversion module further includes a magnetic flux connection unit constructed of a metallic soft magnetic material with high magnetic permeability. The magnetic flux connection unit is located between the plane formed by the X-axis and Y-axis of the first magnetic flux conversion unit and the plane formed by the X-axis and Y-axis of the second magnetic flux conversion unit. The metallic soft magnetic material of the magnetic flux connection unit is distributed along the X-axis, connecting the magnetic flux paths of the first and second magnetic flux conversion units and guiding them parallel to the X-axis. The magnetic induction unit is located within the metallic soft magnetic material of the magnetic flux connection unit or in the gap between it and the metallic soft magnetic material of the magnetic flux conversion module.

[0011] Optionally, the magnetic flux conversion module includes, in addition to the first and second magnetic flux conversion units, an enhanced magnetic flux conversion unit made of a high-permeability metallic soft magnetic material. The enhanced magnetic flux conversion unit is superimposed on the first and / or second magnetic flux conversion units in the Z-axis direction to further focus and amplify the magnetic field to be measured.

[0012] Optionally, the magnetic induction unit is composed of one or more magnetoresistance sensitive elements connected in series and parallel. The magnetoresistance sensitive element is any one of anisotropic magnetoresistance (AMR), giant magnetoresistance (GMR), and tunnel magnetoresistance (TMR). Optionally, the output module includes an open-loop signal conditioning circuit, or a closed-loop signal conditioning circuit and a magnetic field feedback coil. The open-loop signal conditioning circuit conditions, amplifies, temperature compensates, and corrects the linearity of the differential voltage signal to form the output signal of the Z-axis magnetic field sensor. The closed-loop signal conditioning circuit, the magnetic field feedback coil, and the magnetic induction unit constitute a closed-loop magnetic field feedback structure. After the 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 the output signal of the Z-axis magnetic field sensor.

[0013] Optionally, the Z-axis magnetic field sensor further includes a lead pad and a mechanical support housing; the Z-axis magnetic field sensor is manufactured using a single-chip integration process.

[0014] According to a second aspect of the present application, there is provided a Z-axis magnetic field sensor processing method, which is used to process a Z-axis magnetic field sensor including a substrate, a magnetic flux conversion module and a magnetic induction module; the magnetic induction module includes at least two magnetic induction units; the magnetic flux conversion module includes at least one first magnetic flux conversion unit and at least one second magnetic flux conversion unit; the Z-axis magnetic field sensor processing method comprises: depositing an MR magnetoresistive film on the surface of the substrate and processing to form the magnetic induction unit; depositing a passivation layer on the surface of the substrate on which the magnetic induction unit is deposited; wherein the passivation layer is used to protect the magnetic induction unit; forming one or more grooves spaced apart along the X-axis direction on the substrate, and depositing a high magnetic permeability metal soft magnetic material in the groove to form the first magnetic flux conversion unit in the magnetic flux conversion module; depositing a passivation layer on the substrate passivation layer; and semiconductor micromachining to form one or more spaced-apart metal soft magnetic materials, constituting the second magnetic flux conversion unit in the magnetic flux conversion module; the first magnetic flux conversion unit and the second magnetic flux conversion unit are evenly arranged on both sides of the magnetic induction unit; wherein the projections of the first magnetic flux conversion unit and the second magnetic flux conversion unit on the X-axis do not overlap or the overlapping part is less than the overlapping threshold; the overlapping threshold is related to the measurement range of the magnetic field sensor; wherein the magnetic flux conversion module is used to modulate the magnetic field to be measured and generate a magnetic field component in the X-axis direction to form a target magnetic flux path; the magnetic induction unit is used to generate a differential voltage signal under the action of the target magnetic flux path; the plane where the substrate is located is the plane formed by the X-axis and the Y-axis, the magnetic flux conversion module is arranged along the X-axis direction, and the plane perpendicular to the plane where the substrate is located is the plane where the Z-axis is located.

[0015] Optionally, a reverse DRIE deep reactive ion etching process is used to form a groove on the substrate, with the groove opening located on the side of the substrate away from the MR magnetoresistive film; after depositing the metal soft magnetic material, a CMP chemical mechanical polishing process is used for polishing.

[0016] Optionally, one or more metal soft magnetic materials are deposited on the surface where the MR magnetoresistive film is located and / or on the surface of the substrate adjacent to the MR magnetoresistive film and are spaced apart along the X-axis direction to form a magnetic flux connection unit.

[0017] Optionally, an enhanced magnetic flux conversion unit is stacked along the Z-axis direction on the second magnetic flux conversion unit formed by depositing a metal soft magnetic material on the surface of the substrate away from the MR magnetoresistive film and / or on the surface of the substrate where the MR magnetoresistive film is located.

[0018] Optionally, the MR magnetoresistive film includes anisotropic magnetoresistance (AMR), giant magnetoresistance (GMR), or tunnel magnetoresistance (TMR).

[0019] Optionally, the Z-axis magnetic field sensor is packaged in a single chip by using WLP wafer-level packaging and TSV through-silicon via technology, with lead pads and circuits attached, to be packaged into a single chip.

[0020] A third aspect of the present application provides a Z-axis magnetic field sensor processing method, the processing method being used to process a Z-axis magnetic field sensor comprising a substrate, a magnetic flux conversion module, and a magnetic induction module; the magnetic induction module comprising at least two magnetic induction units; the magnetic flux conversion module comprising at least one first magnetic flux conversion unit and at least one second magnetic flux conversion unit; the Z-axis magnetic field sensor processing method comprising: forming one or more spaced-apart metal soft magnetic materials on the substrate by deposition and semiconductor micromachining to form the first magnetic flux conversion unit, polishing the metal soft magnetic materials using a CMP chemical mechanical polishing process and depositing a passivation layer; depositing an MR magnetoresistive film on the surface of the passivation layer, and forming the magnetic induction units in the magnetic induction module by semiconductor patterning micromachining; depositing a passivation layer again on the magnetic induction units, and then forming one or more spaced-apart metal soft magnetic materials on the passivation layer by deposition and semiconductor micromachining to form the second magnetic flux conversion units in the magnetic flux conversion module. The first magnetic flux conversion unit and the second magnetic flux conversion unit are evenly arranged on both sides of the magnetic induction unit; wherein the projections of the first magnetic flux conversion unit and the second magnetic flux conversion unit on the X-axis do not overlap or the overlapping part is less than the overlap threshold; the overlap threshold is related to the measurement range of the magnetic field sensor; wherein the magnetic flux conversion module is used to modulate the magnetic field to be measured to generate a magnetic field component in the X-axis direction to form a target magnetic flux path; the magnetic induction unit is used to generate a differential voltage signal under the action of the target magnetic flux path; the plane where the substrate is located is the plane formed by the X-axis and the Y-axis, the magnetic flux conversion module is arranged along the X-axis direction, and the plane perpendicular to the plane where the substrate is located is the plane where the Z-axis is located.

[0021] Optionally, a reverse DRIE deep reactive ion etching process is used to form a groove on the substrate, with the groove opening located on the side of the substrate away from the MR magnetoresistive film; after depositing the metal soft magnetic material, a CMP chemical mechanical polishing process is used for polishing.

[0022] Optionally, one or more metal soft magnetic materials are deposited on the surface where the MR magnetoresistive film is located and / or on the surface of the substrate adjacent to the MR magnetoresistive film and are spaced apart along the X-axis direction to form a magnetic flux connection unit.

[0023] Optionally, an enhanced magnetic flux conversion unit is stacked along the Z-axis direction on the second magnetic flux conversion unit formed by depositing a metal soft magnetic material on the surface of the substrate away from the MR magnetoresistive film and / or on the surface of the substrate where the MR magnetoresistive film is located.

[0024] Optionally, the MR magnetoresistive film includes anisotropic magnetoresistance (AMR), giant magnetoresistance (GMR), or tunnel magnetoresistance (TMR). Optionally, the Z-axis magnetic field sensor is packaged in a single chip using a WLP wafer-level packaging (WLP) and TSV (Through Silicon Via) process, with lead pads and circuitry attached to form a single chip.

[0025] The fourth aspect of the present application provides a Z-axis magnetic field sensor processing method, which is used to process a Z-axis magnetic field sensor including a substrate, a magnetic flux conversion module, and a magnetic induction module; the magnetic induction module includes at least two magnetic induction units; the magnetic flux conversion module includes at least one first magnetic flux conversion unit and at least one second magnetic flux conversion unit; the substrate includes a first substrate and a second substrate; the Z-axis magnetic field sensor processing method includes: depositing an MR magnetoresistive film on the surface of the first substrate, forming the magnetic induction unit in the magnetic induction module through semiconductor patterning micromachining, and then depositing a non-conductive passivation layer on the substrate to protect the magnetic induction unit. Using a reverse-side DRIE deep reactive ion etching process on the first substrate, one or more spaced grooves are formed on the side of the first substrate away from the MR magnetoresistive film; depositing a metal soft magnetic material in the groove and polishing it using a CMP chemical mechanical polishing process to form the first magnetic flux conversion unit in the magnetic flux conversion module. The second substrate adopts the same process flow as the first substrate to form the magnetic induction unit and the second magnetic flux conversion unit, or does not deposit the MR magnetoresistive film. The subsequent process flow is similar to that of the first substrate. A reverse DRIE process is used to form one or more spaced grooves. After depositing the metal soft magnetic material, a CMP process is used to form the second magnetic flux conversion unit.

[0026] Using the WLP wafer-level packaging process, the first and second substrates are positioned relative to each other along the Z-axis, with the first and second magnetic flux conversion units evenly positioned on either side of the magnetic sensing unit. The projections of the first and second magnetic flux conversion units on the X-axis do not overlap, or the overlap is less than an overlap threshold; the overlap threshold is related to the measurement range of the magnetic field sensor. The MR magnetoresistive film is positioned along the X-axis at the interval between the metallic soft magnetic materials of adjacent first and second magnetic flux conversion units. The MR magnetoresistive films on the same substrate have the same sensitivity direction. If the second substrate contains a magnetic sensing unit, after the first and second substrates are positioned relative to each other along the Z-axis and packaged, the sensitivity directions of the magnetic sensing units of the first and second substrates are both parallel to the plane formed by the X and Y axes.

[0027] Optionally, one or more metal soft magnetic materials are deposited on the surface where the MR magnetoresistive film is located and / or on the surface of the substrate adjacent to the MR magnetoresistive film and are spaced apart along the X-axis direction to form a magnetic flux connection unit.

[0028] Optionally, an enhanced magnetic flux conversion unit comprising a high permeability metallic soft magnetic material is further stacked along the Z-axis direction on the second magnetic flux conversion unit formed by depositing a metallic soft magnetic material on the surface of the substrate away from the MR magnetoresistive film and / or on the surface of the substrate where the MR magnetoresistive film is located.

[0029] Optionally, the MR magnetoresistive film includes anisotropic magnetoresistive AMR, giant magnetoresistive GMR, and tunnel magnetoresistive TMR.

[0030] Optionally, the Z-axis magnetic field sensor is packaged in a single chip, and is packaged into a single chip by adding lead pads and circuits through WLP wafer-level packaging and TSV through-silicon via technology.

[0031] The Z-axis magnetic field sensor provided in the embodiment of the present application is achieved by placing the first magnetic induction unit between the magnetic flux conversion modules along the Z-axis direction; wherein, the magnetic field to be measured is distorted in the X-axis direction under the action of the magnetic flux conversion module, and an X-axis magnetic field component is generated at the position of the first magnetic induction unit to form a target magnetic flux path; the first magnetic induction unit generates a differential voltage signal under the action of the target magnetic flux path; further, the size of the Z-axis magnetic field can be measured based on the differential voltage signal. It can be seen that the Z-axis magnetic field sensor provided in the embodiment of the present application realizes the guidance of the Z-axis direction magnetic circuit in the X-axis direction, enhances the magnetic field concentration effect and magnetic field uniformity, has higher magnetic field conversion efficiency, improves sensitivity, and solves the problems of low sensitivity, poor accuracy, and high noise of the existing Z-axis magnetic field sensor. BRIEF DESCRIPTION OF THE DRAWINGS

[0032] FIG1 is a schematic diagram of a Z-axis magnetic field sensor and a processing method thereof provided in an embodiment of the present application;

[0033] FIG2 is a simulation diagram of a magnetic flux path of a Z-axis magnetic field sensor provided in an embodiment of the present application;

[0034] FIG3 is a simulation result of the magnetic field component in the X-axis direction of the prior art;

[0035] FIG4 is a simulation result of the magnetic field component in the X-axis direction provided by the present application;

[0036] FIG5 is a schematic diagram of another Z-axis magnetic field sensor and a processing method thereof provided in an embodiment of the present application;

[0037] FIG6 is a schematic diagram of a Z-axis magnetic field sensor superimposed with an enhanced magnetic flux conversion unit according to an embodiment of the present application;

[0038] FIG7 is a schematic diagram of another Z-axis magnetic field sensor and a processing method thereof provided in an embodiment of the present application;

[0039] FIG8 is a schematic diagram of another Z-axis magnetic field sensor and a processing method thereof provided in an embodiment of the present application;

[0040] FIG9 is a schematic diagram of another Z-axis magnetic field sensor and a processing method thereof provided by an embodiment of the present invention. DETAILED DESCRIPTION

[0041] The technical solutions in the embodiments of the present application will be described below in conjunction with the accompanying drawings in the embodiments of the present application. For example, the flowcharts and block diagrams in the accompanying drawings illustrate the possible architectures, functions, and operations of the systems, methods, and computer program products according to various embodiments of the present invention. In this regard, each box in the flowchart or block diagram may represent a module, program segment, or portion of code, which contains one or more executable instructions for implementing the specified logical functions. It should also be noted that in some alternative implementations, the functions marked in the boxes may also occur in an order different from that marked in the drawings. For example, two consecutive boxes may actually be executed substantially in parallel, or they may sometimes be executed in the opposite order, depending on the functions involved. It should also be noted that each box in the block diagram and / or flowchart, as well as the combination of boxes in the block diagram and / or flowchart, may be implemented using a dedicated hardware-based system that performs the specified functions or actions, or may be implemented using a combination of dedicated hardware and computer instructions. In addition, the functional modules in the various embodiments of the present invention may be integrated together to form a separate part, or each module may exist separately, or two or more modules may be integrated to form a separate part.

[0042] Magnetic sensors can measure physical parameters such as current, position, motion, and direction by sensing changes in magnetic field strength. For example, in current measurement, a magnetic sensor can be used to measure the current flowing through a wire. By passing the wire through the magnetic sensor, when current flows through the wire, a change in the magnetic field is generated nearby. The magnetic sensor can detect this change and convert it into an electrical signal. In position and motion measurement, magnetic sensors can be used to detect the position and motion of an object. By placing a magnetic sensor between the object and a reference magnet, changes in the magnetic field can be measured and the object's position and motion state can be determined. Magnetic sensors can also be used to determine direction. For example, an electronic compass uses a magnetic sensor to detect the Earth's magnetic field and determines the direction of the navigation device based on the direction of the magnetic field.

[0043] During the research process, the applicant found that the measurement of the Z-axis magnetic field is usually involved in this process, that is, measuring the magnetic field in the normal direction of the plane where the magnetic sensor is located. At present, the measurement of the Z-axis magnetic field is mainly achieved by means of detection coils, Hall elements or magnetoresistive elements. The detection coil has low spatial resolution, limited sensitivity and limited frequency characteristics; the Hall element has low sensitivity, high power consumption and poor temperature characteristics; unlike the Hall sensor, the sensitive direction of the common magnetoresistive sensors, including anisotropic magnetoresistive (AMR), giant magnetoresistive (GMR), and tunnel magnetoresistive (TMR) sensors, is in the in-plane direction, which limits the application of magnetoresistive sensors in situations such as vertical magnetic fields and three-axis vector magnetic field detection. In the application of electronic compasses and miniature three-axis magnetometers, due to the in-plane sensing characteristics of the magnetoresistive sensor, the chip with the in-plane X / Y axis sensitive direction needs to be installed vertically to sense the vertical magnetic field, which significantly increases the volume of the packaged electronic compass, affecting the miniaturization and comprehensive performance of the chip.

[0044] In order to adapt to the application of vertical magnetic field detection, the current magnetoresistive sensors mainly have the following methods:

[0045] (1) Although vertically mounting the magnetic field sensor with in-plane sensitive direction can realize the detection of vertical magnetic field, it usually increases the volume, brings inconvenience in application, and affects the performance.

[0046] (2) TMR sensors with a vertical sensitive direction. However, the magnetoresistance change rate in the vertical sensitive direction is relatively low, typically only reaching 20-40%, far lower than the 250% level at room temperature in the in-plane sensitive direction. At the same time, the saturation magnetic field of the vertical sensitive sensor is relatively high, typically around 1000 Oe. Due to these limitations, the sensitivity of the manufactured vertical sensitive sensors can only be around 0.1 mV / V / Oe. As a result, the signal-to-noise ratio of existing vertical sensitive sensors deteriorates, and the performance advantages of magnetoresistive sensors cannot be fully utilized.

[0047] (3) The magnetic field in the perpendicular Z-axis direction can be bent and converted into a magnetic field in the X-axis and Y-axis directions in the plane by using a soft magnetic sheet for measurement. However, the magnetic flux gathering structure currently used is usually a layer of long strips of soft magnetic alloy arrays, which are deposited on the substrate. This results in an uneven distribution of the magnetic field in the measurement direction, making it difficult to achieve high precision. In addition, the low conversion efficiency also leads to sensitivity loss and high noise levels. Taking the TMR magnetoresistive sensor as an example, the sensitivity of the chip after conversion is about 0.1mV / V / Oe, and the corresponding background noise is two orders of magnitude higher than the TMR in the in-plane sensing direction.

[0048] Based on this, the present application provides a Z-axis magnetic field sensor, a preparation method and an electronic device; wherein, the Z-axis magnetic field sensor realizes the guidance of the Z-axis magnetic circuit in the X-axis direction by setting a special structure of a magnetic flux conversion module and a magnetic induction unit, thereby enhancing the magnetic concentration effect and magnetic field uniformity, and achieving higher magnetic field conversion efficiency and improved sensitivity, thereby solving the problems of low sensitivity, poor accuracy and high noise of existing Z-axis magnetic field sensors.

[0049] Example 1

[0050] Figure 1 is a schematic diagram of a Z-axis magnetic field sensor and its processing method provided in an embodiment of the present application; as shown in Figure 1, the Z-axis magnetic field sensor provided in this embodiment includes: a substrate 1, a magnetic flux conversion module 2, a magnetic induction module 3, and an output module.

[0051] The cross section shown in FIG1 is located in the XZ plane. The magnetic flux conversion module 2 includes a first magnetic flux conversion unit 21 and a second magnetic flux conversion unit 22 made of a high magnetic permeability metallic soft magnetic material. The magnetic induction unit 31 in the magnetic induction module 3 adopts a tunnel magnetoresistance TMR deposited on the substrate 1.

[0052] The first magnetic flux conversion unit 21 is located in the groove of the substrate 1, and the second magnetic flux conversion unit 22 is located above the substrate 1; as shown in Figure 1, the metal soft magnetic materials of the first magnetic flux conversion unit 21 and the second magnetic flux conversion unit 22 are distributed at intervals in the X-axis direction and their projections in the Z-axis direction do not overlap, and the magnetic induction units 31 are distributed at intervals and their sensitivity directions are all in the positive direction of the X-axis.

[0053] In the embodiment of the present application, the projections of the first magnetic flux conversion unit and the second magnetic flux conversion unit on the X-axis do not overlap or the overlapping portion is smaller than an overlapping threshold, and the overlapping threshold is related to the measurement range of the magnetic field sensor.

[0054] Please refer to Figure 2 based on Figure 1. Figure 2 is a simulation diagram of the magnetic flux path of a Z-axis magnetic field sensor provided in an embodiment of the present application. When performing Z-axis magnetic field detection, the magnetic flux conversion module 2 selects different numbers of soft magnetic alloy structures of the first magnetic flux conversion unit 21 and the second magnetic flux conversion unit 22 according to the actual application situation. By way of example, the magnetic flux conversion module includes three first magnetic flux conversion units 21 and two second magnetic flux conversion units 22. The magnetic field to be measured is gathered and amplified by the metal soft magnetic materials of the first magnetic flux conversion unit 21 and the second magnetic flux conversion unit 22 to form a magnetic circuit. Since the metal soft magnetic materials are distributed at intervals, the magnetic circuit will be distorted in the X-axis direction as shown in Figure 2 when it is converted between the first magnetic flux conversion unit 21 and the second magnetic flux conversion unit 22, generating an X-axis magnetic field component at the location of the magnetic induction unit 31.

[0055] FIG3 shows the simulation results of the X-axis magnetic field component of the prior art. As shown in FIG3 , the prior art adopts a single-layer array of elongated soft magnetic alloy structures, which is equivalent to containing only the first magnetic flux conversion unit or the second magnetic flux conversion unit of the present invention. The single-layer array of elongated soft magnetic alloy structures of the prior art is located in the plane where the first magnetic flux conversion unit 21 is located for simulation. FIG3 shows the X-axis magnetic field component results at the horizontal line where the magnetic induction unit 31 is located after the single-layer array of elongated soft magnetic alloy structures of the prior art are simulated with a 0.1mT Z-axis magnetic field. As can be seen from FIG3 , although the prior art can convert the Z-axis magnetic field into an X-axis magnetic field component that can be differentially measured, its magnetic field distribution is not uniform, which easily produces zero-point drift and makes it difficult to achieve high precision. In addition, the deposition method of the prior art is limited by the thickness of the metal soft magnetic material. The X-axis magnetic field component generated by the Z-axis magnetic field after aggregation and conversion is small, resulting in serious sensitivity loss and high device noise.

[0056] Please refer to Figure 4, which is a simulation result of the X-axis direction magnetic field component provided by the present application; the present application adopts a staggered arrangement of the first magnetic flux conversion unit 21 and the second magnetic flux conversion unit 22 for magnetic flux conversion, and can combine the reverse DRIE deep reactive ion etching process or the superposition enhancement magnetic flux conversion unit to increase the thickness of the metal soft magnetic material to enhance the magnetic concentration effect. Figure 4 shows the X-axis direction magnetic field component result of the horizontal line where the magnetic induction unit 31 is located after simulating a two-layer spaced-apart metal soft magnetic material structure (containing the first magnetic flux conversion unit 21 and the second magnetic flux conversion unit 22) of the present invention with a Z-axis magnetic field of 0.1mT. It can be seen from Figure 4 that due to the magnetic circuit guiding effect of the magnetic flux conversion module 2 structure in the embodiment of the present application, the curve shown in Figure 4 is smoother than Figure 3, the peak value is more uniform, and the sensitivity is higher and the noise is smaller.

[0057] Continuing with FIG. 1 , for the embodiment shown in FIG. 1 , the magnetic induction module 3 includes four magnetic induction units 31 , namely, magnetic induction units 31 a, 31 b, 31 c, and 31 d, located in the Z-axis direction between the plane formed by the X-axis and Y-axis of the first magnetic flux conversion unit 21 and the plane formed by the X-axis and Y-axis of the second magnetic flux conversion unit 22. Furthermore, the four magnetic induction units 31 are located in the X-axis direction at intervals between the metallic soft magnetic materials of adjacent first magnetic flux conversion units 21 and second magnetic flux conversion units 22. All magnetic induction units 31 are located in the same plane formed by the X-axis and Y-axis in the Z-axis direction and have the same sensitivity direction, which is the positive direction of the X-axis. When the magnetic field to be measured is in the positive direction of the Z axis, the converted X-axis magnetic field component in Figure 1 is to the right (positive X direction) at the position of magnetic induction units 31a and 31c, and to the left (negative X direction) at the position of magnetic induction units 31b and 31d; since the sensitivity direction of magnetic induction unit 31 is the positive X direction, the resistance values ​​of magnetic induction units 31a and 31c decrease, while the resistance values ​​of magnetic induction units 31b and 31d increase.

[0058] Therefore, the magnetic induction module 3 can use a push-pull full-bridge structure to sense the magnetic field of the magnetic flux conversion module 2 and generate a differential voltage signal. The output module in this embodiment uses an open-loop signal conditioning circuit to condition, amplify, temperature-compensate, and linearize the differential voltage signal to form the output signal of the Z-axis magnetic field sensor. Because the magnetic induction unit 31 in this embodiment has the same sensitivity direction, it can be combined with lead pads and a mechanical support housing using a single-chip integrated manufacturing process.

[0059] The following is a processing method corresponding to the Z-axis magnetic field sensor provided in this embodiment. As shown in Figure 1, a substrate 1 is provided. A TMR magnetoresistive film is deposited on the surface of the substrate 1 and semiconductor patterning micromachining is used to form magnetic sensing units 31a, 31b, 31c, and 31d, which are connected to form a push-pull full-bridge structure. A non-conductive passivation layer is then deposited on the substrate 1 to protect the magnetic sensing unit 31. Interspaced grooves are etched on the substrate 1, and high-permeability metal soft magnetic material is deposited in the grooves to form the first magnetic flux conversion unit 21. Metal soft magnetic material is further deposited above the passivation layer of the substrate 1, and semiconductor micromachining is used to form another layer of metal soft magnetic structure that is spaced apart from the metal soft magnetic material of the first magnetic flux conversion unit 21, forming the second magnetic flux conversion unit 22. The metal soft magnetic material of the second magnetic flux conversion unit 22 has an area spaced apart from the metal soft magnetic material of the first magnetic flux conversion unit 21 in the X-axis direction, and the projections of the metal soft magnetic materials of adjacent first magnetic flux conversion units 21 and second magnetic flux conversion units 22 in the Z-axis direction do not overlap in this spaced apart area. The TMR magnetoresistive film is located in the X-axis direction at the interval between the metal soft magnetic materials of the adjacent first magnetic flux conversion unit 21 and the second magnetic flux conversion unit 22. This embodiment can be combined with the lead pad and the mechanical support housing to form a single chip.

[0060] It can be seen that the Z-axis magnetic field sensor and its processing method provided in this embodiment deposits metal soft magnetic materials on both the surface of the substrate 1 and the inside of the groove, forming a metal soft magnetic material structure in which the first magnetic flux conversion unit 21 and the second magnetic flux conversion unit 22 are spaced apart and the projections in the Z-axis direction do not overlap, thereby achieving the guidance of the Z-axis direction magnetic circuit in the X-axis direction, enhancing the magnetic concentration effect and magnetic field uniformity, and improving the magnetic field conversion efficiency; improving the sensitivity, and solving the problems of low sensitivity, poor accuracy, and high noise of the existing Z-axis magnetic field sensor. At the same time, since the present application can simultaneously generate magnetic field components in the positive and negative directions of the X-axis, the magnetic induction unit can realize push-pull full-bridge measurement by using only the same sensitivity direction; compared with the existing technology using multiple sensitivity direction magnetic induction units, the preparation steps are simplified, the sensitivity consistency is better, the temperature drift is smaller, the stability is good, and a single-chip preparation process can be realized.

[0061] Example 2

[0062] Please refer to Figure 5, which is a schematic diagram of another Z-axis magnetic field sensor and its processing method provided in an embodiment of the present application; the Z-axis magnetic field sensor provided in this embodiment includes: a substrate 1, a magnetic flux conversion module 2, a magnetic induction module 3, and an output module.

[0063] As shown in Figure 5, the cross-section of the Z-axis magnetic field sensor is located in the XZ plane, and the magnetic flux conversion module 2 includes a first magnetic flux conversion unit 21 and a second magnetic flux conversion unit 22 made of high-permeability metallic soft magnetic material. The magnetic induction unit 31 in the magnetic induction module 3 uses a giant magnetoresistance (GMR) deposited on the substrate 1. The first magnetic flux conversion unit 21 is located in the groove of the substrate 1, and the second magnetic flux conversion unit 22 is located above the substrate 1. As shown in Figure 5, the groove opening of the substrate 1 is located on the side of the substrate 1 away from the magnetoresistive film of the magnetic induction unit 31, and is processed using a DRIE deep reactive ion etching process, so that the thickness of the metal soft magnetic material deposited in the groove can be significantly greater than the thickness of the process directly deposited on the surface of the substrate 1. The metal soft magnetic materials of the first magnetic flux conversion unit 21 and the second magnetic flux conversion unit 22 are spaced apart in the X-axis direction, and their projections in the Z-axis direction do not overlap. The magnetic induction module 3 includes four magnetic induction units 31 located between the plane formed by the X-axis and Y-axis of the first magnetic flux conversion unit 21 and the plane formed by the X-axis and Y-axis of the second magnetic flux conversion unit 22 in the Z-axis direction, and located at the intervals between the metal soft magnetic materials of the adjacent first magnetic flux conversion units 21 and the second magnetic flux conversion units 22 in the X-axis direction. The sensitivity directions of the magnetic induction units 31a, 31b, 31c, and 31d are all in the positive direction of the X-axis.

[0064] Similarly, taking the magnetic field to be measured as the positive direction of the Z axis as an example, the metallic soft magnetic material of the first magnetic flux conversion unit 21 and the second magnetic flux conversion unit 22 concentrates and amplifies the magnetic field to be measured. The magnetic circuit is distorted in the X-axis direction when converting between the first magnetic flux conversion unit 21 and the second magnetic flux conversion unit 22. The converted X-axis magnetic field component is rightward at the positions of magnetic induction units 31a and 31c, and leftward at the positions of magnetic induction units 31b and 31d. The resistance values ​​of magnetic induction units 31a and 31c decrease, while the resistance values ​​of magnetic induction units 31b and 31d increase. Therefore, by connecting magnetic induction units 31a, 31b, 31c, and 31d in series and parallel with a reference resistor, magnetic induction module 3 can use a differential full-bridge structure to sense the magnetic field of magnetic flux conversion module 2 and generate a differential voltage signal. The output module in this embodiment uses an open-loop signal conditioning circuit to condition, amplify, temperature compensate, and perform linearity correction on the differential voltage signal to form the output signal of the Z-axis magnetic field sensor.

[0065] The following is a processing method corresponding to the Z-axis magnetic field sensor provided in this embodiment. As shown in FIG5 , a substrate 1 is provided. A GMR magnetoresistive film is deposited on the surface of the substrate 1, and magnetic sensing units 31a, 31b, 31c, 31d and a reference resistor are formed through semiconductor patterning micromachining, and are connected to form a differential full-bridge structure. A non-conductive passivation layer is deposited on the substrate 1 to protect the magnetic sensing units 31. A reverse-side deep reactive ion etching (DRIE) process is used to form spaced grooves on the side of the substrate 1 away from the GMR magnetoresistive film. A metal soft magnetic material is deposited in the grooves through electroplating, chemical plating, or other processes, and polished using a CMP chemical mechanical polishing process to form the first magnetic flux conversion unit 21 in the magnetic flux conversion module 2. A metal soft magnetic material is further deposited above the passivation layer on the surface of the substrate 1 where the GMR magnetoresistive film is located. Semiconductor micromachining is used to form another layer of metal soft magnetic structure spaced apart from the metal soft magnetic material of the first magnetic flux conversion unit 21, forming the second magnetic flux conversion unit 22. The metallic soft magnetic material of the second magnetic flux conversion unit 22 is spaced apart from the metallic soft magnetic material of the first magnetic flux conversion unit 21 in the X-axis direction, and the projections of the metallic soft magnetic materials of adjacent first magnetic flux conversion units 21 and second magnetic flux conversion units 22 in this spaced apart region in the Z-axis direction do not overlap. The GMR magnetoresistive film is located in the X-axis direction at a position spaced apart from the metallic soft magnetic materials of adjacent first magnetic flux conversion units 21 and second magnetic flux conversion units 22.

[0066] It can be seen from this that this embodiment introduces the reverse DRIE deep reactive ion etching process, increases the groove depth, and achieves a significant increase in the thickness of the metal soft magnetic material of the first magnetic flux conversion unit 21. Therefore, on the basis of Example 1, the magnetic flux concentration effect and conversion are further enhanced, the sensitivity is further improved, and it is beneficial to reduce sensor noise.

[0067] In addition, in order to further enhance the magnetic concentration effect and improve the sensitivity, the present application also proposes an enhanced magnetic flux conversion unit 23. The enhanced magnetic flux conversion unit 23 contains a high magnetic permeability metal soft magnetic material, which can be superimposed on the upper surface or lower surface of the existing Z-axis magnetic field sensor along the Z-axis direction on the basis of Example 1 and Example 2, so as to further amplify the magnetic field to be measured. Its processing method is to deposit a metal soft magnetic material on the surface of the substrate 1 away from the MR magnetoresistive film or on the surface of the substrate MR magnetoresistive film to form a second magnetic flux conversion unit, and superimpose an enhanced magnetic flux conversion unit containing a high magnetic permeability metal soft magnetic material along the Z-axis direction. For example, please refer to Figure 6, which is a schematic diagram of the Z-axis magnetic field sensor provided by the embodiment of the present application superimposed with an enhanced magnetic flux conversion unit; the upper surface of the embodiment shown in Figure 5 can be superimposed as shown in Figure 6, and the enhanced magnetic flux conversion unit 23 is superimposed on the second magnetic flux conversion unit 22 formed by depositing the metal soft magnetic material. The enhanced magnetic flux conversion unit 23 can be connected to the Z-axis magnetic field sensor by external adhesion or other means, which mainly enhances the magnetic field concentration effect; it can also further regulate the magnetic field distribution to solve the thickness limitation problem of metal soft magnetic materials due to process limitations, enhance the converted X-magnetic field component, and make the magnetic field distribution in the Z-axis direction more uniform.

[0068] Example 3

[0069] Please refer to Figure 7, which is a schematic diagram of another Z-axis magnetic field sensor and its processing method provided in an embodiment of the present application; the Z-axis magnetic field sensor provided in this embodiment includes: a substrate 1, a magnetic flux conversion module 2, a magnetic induction module 3, and an output module.

[0070] As shown in Figure 7, the cross-section of the Z-axis magnetic field sensor lies in the XZ plane. The magnetic flux conversion module 2 includes a first magnetic flux conversion unit 21 and a second magnetic flux conversion unit 22, both made of high-permeability metallic soft magnetic material. The first magnetic flux conversion unit 21 is located above the substrate 1. The magnetic induction unit 31 within the magnetic induction module 3 utilizes anisotropic magnetoresistance (AMR) deposited above the first magnetic flux conversion unit 21. The second magnetic flux conversion unit 22 is located above the magnetic induction unit 31. As shown in Figure 7, the metallic soft magnetic materials of the first and second magnetic flux conversion units 21, 22 are located on the same side of the substrate 1 and are spaced apart in the X-axis direction. The projections of the metallic soft magnetic materials at the edges of the gap between the first and second magnetic flux conversion units 21, 22 in the Z-axis direction partially overlap. The magnetic induction module 3 includes four magnetic induction units 31 located between the plane formed by the X-axis and Y-axis of the first magnetic flux conversion unit 21 and the plane formed by the X-axis and Y-axis of the second magnetic flux conversion unit 22 in the Z-axis direction, and located at the intervals between the metal soft magnetic materials of the adjacent first magnetic flux conversion units 21 and the second magnetic flux conversion units 22 in the X-axis direction. The sensitivity directions of the magnetic induction units 31a, 31b, 31c, and 31d are all in the positive direction of the X-axis.

[0071] Again, taking the measured magnetic field as the positive Z-axis direction as an example, the converted X-axis magnetic field component is rightward at the locations of magnetic sensing units 31a and 31c, and leftward at the locations of magnetic sensing units 31b and 31d. The resistance values ​​of magnetic sensing units 31a and 31c decrease, while the resistance values ​​of magnetic sensing units 31b and 31d increase. Therefore, a portion of magnetic sensing units 31 and a reference resistor can be selected to form a differential half-bridge structure to sense the magnetic field of magnetic flux conversion module 2 and generate a differential voltage signal.

[0072] The output module in this embodiment utilizes a closed-loop signal conditioning circuit and a magnetic field feedback coil. The closed-loop signal conditioning circuit, magnetic field feedback coil, and magnetic induction unit 31 form a closed-loop magnetic field feedback structure. After the differential voltage signal is amplified by the closed-loop signal conditioning circuit, it is passed through the magnetic field feedback coil to generate a feedback magnetic field, achieving dynamic magnetic field equilibrium. The feedback current from the magnetic field feedback coil is sampled to form the output signal of the Z-axis magnetic field sensor. The position of the magnetic field feedback coil can vary depending on the actual situation. It can be a coil arranged along the plane defined by the X- and Y-axes on the upper or lower surface of the substrate 1, or a coil arranged along the Z-axis on all four sides of the substrate 1. Furthermore, the coil arranged along the plane defined by the X- and Y-axes can also be positioned on any of the upper and lower surfaces of the first magnetic flux conversion unit 21, the magnetic induction unit 31, or the second magnetic flux conversion unit 22. Since magnetic field feedback coils are an existing foundational technology, they will not be described in detail. In this embodiment, the magnetic field feedback coil is positioned on the upper surface of the magnetic induction unit 31 (the lower surface of the second magnetic flux conversion unit 22).

[0073] The following is a processing method corresponding to the Z-axis magnetic field sensor provided in this embodiment. Please refer to Figure 7, which is a schematic diagram of another Z-axis magnetic field sensor and its processing method provided in an embodiment of the present application. The processing method includes: providing a substrate 1, and forming a metal soft magnetic material distributed at intervals above the substrate 1 by deposition and semiconductor micromachining to form a first magnetic flux conversion unit 21. The surface of the first magnetic flux conversion unit 21 is polished using a CMP chemical mechanical polishing process and a passivation layer is deposited. An AMR magnetoresistive film is deposited on the surface of the passivation layer and semiconductor patterned micromachining is used to form magnetic sensing units 31a, 31b, 31c, 31d and a reference resistor, which are connected to form a differential half-bridge structure. A passivation layer is deposited again above the magnetic sensing unit 31 to protect the magnetoresistive film, and a magnetic field feedback coil is prepared. Then, another layer of metal soft magnetic structure distributed at intervals from the metal soft magnetic material of the first magnetic flux conversion unit 21 is formed by deposition and semiconductor micromachining to form a second magnetic flux conversion unit 22. The metallic soft magnetic material of the second magnetic flux conversion unit 22 is spaced apart from the metallic soft magnetic material of the first magnetic flux conversion unit 21 in the X-axis direction. Within this spaced apart area, the projections of the metallic soft magnetic materials of adjacent first magnetic flux conversion units 21 and second magnetic flux conversion units 22 in the Z-axis direction partially overlap, with the overlapping length being less than 1 / 2 of the length of the metallic soft magnetic materials of adjacent first magnetic flux conversion units 21 and second magnetic flux conversion units 22. The AMR magnetoresistive film is located in the X-axis direction at the position separating the metallic soft magnetic materials of adjacent first magnetic flux conversion units 21 and second magnetic flux conversion units 22.

[0074] In summary, this embodiment deposits two layers of metallic soft magnetic material directly on the same surface of substrate 1, rather than using a trench process. This results in a metallic soft magnetic material structure with first and second magnetic flux conversion units 21 and 22 spaced apart and partially overlapping in their Z-axis projections. Compared to other embodiments that require etching on substrate 1, this reduces the complexity of the process steps and facilitates production. Furthermore, this embodiment utilizes closed-loop negative feedback, resulting in high precision and good linearity.

[0075] Example 4

[0076] Please refer to Figure 8, which is a schematic diagram of another Z-axis magnetic field sensor and its processing method provided in an embodiment of the present invention; the Z-axis magnetic field sensor provided in this embodiment includes: a substrate 1, a magnetic flux conversion module 2, a magnetic induction module 3, and an output module.

[0077] As shown in Figure 8, the cross-section of the Z-axis magnetic field sensor lies in the XZ plane. The substrate 1 of this embodiment comprises a first substrate 1a and a second substrate 1b. The magnetic flux conversion module 2 includes a first magnetic flux conversion unit 21 and a second magnetic flux conversion unit 22 made of high-permeability metallic soft magnetic material. The magnetic induction unit 31 within the magnetic induction module 3 utilizes tunnel magnetoresistors (TMRs) deposited on the first and second substrates 1a, 1b. The first magnetic flux conversion unit 21 is located within a groove in the first substrate 1a, and the second magnetic flux conversion unit 22 is located within a groove in the second substrate 1b. As shown in Figure 8, the groove openings of the first and second substrates 1a, 1b are located on the side of the first and second substrates 1a, 1b away from their respective magnetoresistive films. Deep reactive ion etching (DRIE) is used to increase the groove depth and the thickness of the metallic soft magnetic material deposited within the grooves. The metallic soft magnetic materials of the first and second magnetic flux conversion units 21, 22 are spaced apart in the X-axis direction, and their projections in the Z-axis direction do not overlap. The magnetic induction units 31a and 31b are located on the first substrate 1a, and the magnetic induction units 31c and 31d are located on the second substrate 1b.

[0078] Using a single chip packaging process, WLP wafer-level advanced packaging and TSV (Through Silicon Via) technology to attach lead pads and circuits, the first substrate 1a and second substrate 1b are packaged with their tunnel magnetoresistors (TMRs) facing each other, forming a single chip. The magnetic sensing units 31a, 31b, 31c, and 31d are all located between the metal soft magnetic material. After packaging, the magnetic sensing units 31a, 31b, 31c, and 31d are located in the Z-axis direction between the plane formed by the X-axis and Y-axis of the first magnetic flux conversion unit 21 and the plane formed by the X-axis and Y-axis of the second magnetic flux conversion unit 22, and are also located between the first substrate 1a and the second substrate 1b. According to the different directions selected within the plane formed by the X-axis and the Y-axis when the first substrate 1a and the second substrate 1b are relatively arranged and packaged along the Z-axis, the sensitivity directions of the magnetic induction units 31a, 31b and the magnetic induction units 31c, 31d after packaging are correspondingly different. In this embodiment, the sensitivity direction of the first-plane magnetic induction units 31a, 31b after packaging is the positive X direction, and the sensitivity direction of the second-plane magnetic induction units 31c, 31d is the negative X direction; the magnetic induction units 31a, 31d are located at the same interval, and the magnetic induction units 31b, 31c are located at the same interval.

[0079] Taking the magnetic field to be measured in the positive Z-axis direction as an example, the metallic soft magnetic material of the first magnetic flux conversion unit 21 and the second magnetic flux conversion unit 22 concentrates and amplifies the magnetic field to be measured. The magnetic circuit is distorted in the X-axis direction when converting between the first magnetic flux conversion unit 21 and the second magnetic flux conversion unit 22. The converted X-axis magnetic field component is rightward at the locations of magnetic induction units 31a and 31d, and leftward at the locations of magnetic induction units 31b and 31c. Since the sensitivity of the packaged first planar magnetic induction units 31a and 31b is rightward (positive X-direction), and the sensitivity of the second planar magnetic induction units 31c and 31d is leftward (negative X-direction), the resistance of magnetic induction units 31a and 31c decreases, while the resistance of magnetic induction units 31b and 31d increases. Therefore, magnetic induction units 31a and 31d or magnetic induction units 31b and 31c at the same spacing can be selected to form a push-pull half-bridge structure to sense the magnetic field of magnetic flux conversion module 2 and generate a differential voltage signal. The output module in this embodiment uses an open-loop signal conditioning circuit to condition, amplify, temperature compensate, and perform linearity correction on the differential voltage signal to form the output signal of the Z-axis magnetic field sensor.

[0080] The following is a processing method corresponding to the Z-axis magnetic field sensor provided in this embodiment. Referring to FIG. 8 , a first substrate 1a and a second substrate 1b are provided. TMR magnetoresistive films are deposited on the surfaces of the first substrate 1a and the second substrate 1b, respectively, and magnetic sensing units 31a, 31b, 31c, and 31d are formed through semiconductor patterning micromachining. Magnetic sensing units 31a and 31b are located on the first substrate 1a, while magnetic sensing units 31c and 31d are located on the second substrate 1b. A non-conductive passivation layer is deposited on the first substrate 1a and the second substrate 1b to protect the magnetic sensing unit 31. A reverse-surface deep reactive ion etching (DRIE) process is used to form trenches on the sides of the first substrate 1a and the second substrate 1b away from the TMR magnetoresistive film. A metal soft magnetic material is deposited in the trenches and polished using a CMP chemical mechanical polishing process, respectively forming the first magnetic flux conversion unit 21 and the second magnetic flux conversion unit 22 in the magnetic flux conversion module 2. A single chip packaging process is used, using WLP wafer-level advanced packaging and TSV through-silicon via (TSV) technology, to package the first substrate 1a and second substrate 1b with the TMR magnetoresistive film facing each other. Copper wires 4 are used to connect the circuits through the through-silicon vias to form a push-pull half-bridge structure. Lead pads and circuits are then added to form a single chip. The metal soft magnetic material of the second magnetic flux conversion unit 22, after packaging, is spaced apart from the metal soft magnetic material of the first magnetic flux conversion unit 21 in the X-axis direction. Within this spaced-apart area, the projections of the metal soft magnetic materials of adjacent first and second magnetic flux conversion units 21 and 22 in the Z-axis direction do not overlap. The packaged TMR magnetoresistive film is located in the X-axis direction at the interval between the metal soft magnetic materials of adjacent first and second magnetic flux conversion units 21 and 22.

[0081] In summary, this embodiment arranges two substrates containing magnetic sensing units relative to each other, so that the sensitivity directions of the magnetic sensing units located on the first plane and the second plane are opposite, and adopts a single chip package combined with the reverse DRIE deep reactive ion etching process to achieve a significant increase in sensitivity amplification factor based on a small volume, with the advantages of stable structure, high precision and low noise.

[0082] Example 5

[0083] Please refer to Figure 9, which is a schematic diagram of another Z-axis magnetic field sensor and its processing method provided by an embodiment of the present invention. The Z-axis magnetic field sensor provided by this embodiment includes: a substrate 1, a magnetic flux conversion module 2, a magnetic induction module 3, and an output module.

[0084] As shown in Figure 9, the cross-section of this Z-axis magnetic field sensor lies in the XZ plane. The substrate 1 of this embodiment comprises a first substrate 1a and a second substrate 1b. The magnetic flux conversion module 2 includes a first magnetic flux conversion unit 21, a second magnetic flux conversion unit 22, and a magnetic flux connection unit 24, all made of high-permeability metallic soft magnetic material. The magnetic induction unit 31 within the magnetic induction module 3 utilizes a tunnel magnetoresistance (TMR) deposited on the first substrate 1a. The first magnetic flux conversion unit 21 is located within a trench in the first substrate 1a, while the second magnetic flux conversion unit 22 is located within a trench in the second substrate 1b. As shown in Figure 9, the trench opening of the first substrate 1a is located on the side away from the magnetoresistive film. Deep reactive ion etching (DRIE) is used on the first and second substrates 1a, 1b to increase the thickness of the metallic soft magnetic material deposited within the trench. The metallic soft magnetic materials of the first and second magnetic flux conversion units 21 and 22 are spaced apart in the X-axis direction, and their projections in the Z-axis direction do not overlap. The magnetic induction units 31a and 31b are located on the first substrate 1a, and their sensitivity directions are both oriented in the X-axis direction.

[0085] In addition, in this embodiment, a magnetic flux connection unit 24 is deposited on the plane above the magnetic induction unit 31. The magnetic flux connection unit 24 uses a metal soft magnetic material with high magnetic permeability, and is distributed at intervals in the X-axis direction. The projections of the magnetic induction units 31a and 31b in the Z-axis direction are located inside the metal soft magnetic material of the magnetic flux connection unit 24 (at the interval).

[0086] A single chip packaging process is used, using WLP wafer-level advanced packaging and TSV (Through Silicon Via) technology, to position the tunnel magnetoresistance (TMR) surface of the first substrate 1a opposite the non-groove opening surface of the second substrate 1b for packaging. The projections of the magnetic sensing units 31a and 31b in the Z-axis direction are located between the metal soft magnetic materials of the first magnetic flux conversion unit 21 and the second magnetic flux conversion unit 22. As shown in FIG9 , after packaging, the magnetic sensing units 31a and 31b of this embodiment are located in the Z-axis direction between the plane formed by the X-axis and Y-axis of the first magnetic flux conversion unit 21 and the plane formed by the X-axis and Y-axis of the second magnetic flux conversion unit 22, and are also located between the first substrate 1a and the second substrate 1b. Furthermore, their projections in the Z-axis direction are located not only within (at the gap between) the metal soft magnetic material of the magnetic flux connection unit 24, but also in the gap between the magnetic flux connection unit 24 and the metal soft magnetic materials of the first magnetic flux conversion unit 21 and the second magnetic flux conversion unit 22.

[0087] It should be noted that the magnetic flux connection unit 24 can be deposited on the first substrate 1a or on the second substrate 1b, and the plane where the magnetic flux connection unit 24 is located is located between the plane formed by the X-axis and Y-axis of the first magnetic flux conversion unit 21 and the plane formed by the X-axis and Y-axis of the second magnetic flux conversion unit 22; and the projection of the metal soft magnetic material of the magnetic flux connection unit 24 in the Z-axis direction may partially overlap or not overlap with the metal soft magnetic material of the first magnetic flux conversion unit 21 and the second magnetic flux conversion unit 22. As shown in Figure 9, this embodiment adopts a partially overlapping structure. Taking the magnetic field to be measured as the positive direction of the Z-axis as an example, the metal soft magnetic material of the first magnetic flux conversion unit 21 and the second magnetic flux conversion unit 22 concentrates and amplifies the magnetic field to be measured; when the magnetic circuit is twisted to generate the X-axis magnetic field component, the magnetic flux connection unit 24 distributed along the X-axis direction connects the magnetic flux paths of the first magnetic flux conversion unit 21 and the second magnetic flux conversion unit 22 and concentrates and guides the magnetic field in a direction parallel to the X-axis, making the magnetic field distribution more uniform and controllable, and the output result more stable. When the first magnetic flux conversion unit 21 and the second magnetic flux conversion unit 22 are spaced relatively far apart, the magnetic flux connection unit 24 can be constructed of a metallic soft magnetic material that does not overlap with the first magnetic flux conversion unit 21 and the second magnetic flux conversion unit 22, thereby similarly achieving the goal of guiding the magnetic field and improving accuracy. The converted X-axis magnetic field component is directed to the right at the location of magnetic induction unit 31a and to the left at the location of magnetic induction unit 31b. The resistance of magnetic induction unit 31a decreases, while the resistance of magnetic induction unit 31b increases. Therefore, magnetic induction units 31a and 31b can form a push-pull half-bridge structure to sense the magnetic field of magnetic flux conversion module 2 and generate a differential voltage signal.

[0088] The output module in this embodiment utilizes a closed-loop signal conditioning circuit and a magnetic field feedback coil. The closed-loop signal conditioning circuit, magnetic field feedback coil, and magnetic induction unit 31 form a closed-loop magnetic field feedback structure. After the differential voltage signal is amplified by the closed-loop signal conditioning circuit, it is passed through the magnetic field feedback coil to generate a feedback magnetic field, achieving dynamic magnetic field equilibrium. The feedback current from the magnetic field feedback coil is sampled to form the output signal of the Z-axis magnetic field sensor. The position of the magnetic field feedback coil can vary depending on the actual situation. It can be located within the plane defined by the upper and lower surfaces of the first substrate 1a, the first magnetic flux conversion unit 21, the magnetic induction unit 31, the magnetic flux connection unit 24, the second magnetic flux conversion unit 22, or the second substrate 1b, along the X-axis and Y-axis. Alternatively, it can be located on all four sides of the first and second substrates 1a and 1b in the Z-axis direction. Since magnetic field feedback coils are a basic technology, they will not be described in detail. In this embodiment, the magnetic field feedback coil is located on all four sides of the first and second substrates 1a and 1b in the Z-axis direction.

[0089] The following is the processing method of this embodiment. As shown in Figure 9, a first substrate 1a and a second substrate 1b are provided. A TMR magnetoresistive film is deposited on the surface of the first substrate 1a, and magnetic induction units 31a and 31b are formed by semiconductor patterning micromachining. A non-conductive passivation layer is deposited on the first substrate 1a to protect the magnetic induction unit 31. Then, a metal soft magnetic material is deposited above the passivation layer of the magnetic induction unit 31. Semiconductor micromachining is used to form metal soft magnetic materials spaced along the X-axis to form a magnetic flux connection unit 24. A reverse DRIE deep reactive ion etching process is used to form grooves on the second substrate 1b and the side of the first substrate 1a away from the TMR magnetoresistive film. A metal soft magnetic material is deposited in the grooves and polished using a CMP chemical mechanical polishing process, respectively forming the first magnetic flux conversion unit 21 and the second magnetic flux conversion unit 22 in the magnetic flux conversion module 2. A single chip packaging process is used, using the WLP wafer-level advanced packaging process and the TSV through-silicon via (TSV) process, to position the tunnel magnetoresistance (TMR) surface of the first substrate 1a opposite the non-trench opening surface of the second substrate 1b for packaging. Copper wires 4 are used to pass through the TSVs for circuit connection, forming a push-pull half-bridge structure. Lead pads and circuits are then added to form a single chip. After packaging, the metal soft magnetic material of the second magnetic flux conversion unit 22 is spaced apart from the metal soft magnetic material of the first magnetic flux conversion unit 21 in the X-axis direction, and the projections of the metal soft magnetic materials of adjacent first and second magnetic flux conversion units 21 and 22 in the Z-axis direction do not overlap within this spaced-out region. The projections of the metal soft magnetic material of the magnetic flux connection unit 24 in the Z-axis direction partially overlap with the metal soft magnetic materials of the first and second magnetic flux conversion units 21 and 22. The packaged TMR magnetoresistive film is located in the Z-axis direction between the plane formed by the X-axis and Y-axis of the first magnetic flux conversion unit 21 and the plane formed by the X-axis and Y-axis of the second magnetic flux conversion unit 22, and is also located between the first substrate 1a and the second substrate 1b. The projection in the Z-axis direction is not only located inside the metal soft magnetic material of the magnetic flux connection unit 24 (at the gap), but also located in the gap between the magnetic flux connection unit 24 and the metal soft magnetic material of the first magnetic flux conversion unit 21 and the second magnetic flux conversion unit 22.

[0090] As can be seen, this embodiment utilizes a single chip package with two opposing substrates and a DRIE deep reactive ion etching process, and introduces a magnetic flux connection unit 24. Building on the enhanced magnetic field concentration and sensitivity of the original first and second magnetic flux conversion units 21 and 22, this achieves magnetic field concentration and guidance along the X-axis of the magnetic circuit, resulting in a more uniform and controllable magnetic field distribution, greater magnetic field gain, and more stable output results, further improving accuracy and sensitivity while reducing noise.

[0091] In addition, for the bridge structure of the present invention, in addition to using the magnetic induction unit 31 located at the interval position of the metal soft magnetic material and the reference resistor with a constant resistance value mentioned in the existing embodiment, it is also possible to combine the magnetic induction unit 32 (not shown in the figure) located in the coverage range of the metal soft magnetic material or away from the magnetic flux conversion module 2 along the Z-axis direction to form a differential bridge. Such situations are basic existing technologies and will not be described in detail.

Claims

1. A Z-axis magnetic field sensor, characterized in that: The Z-axis magnetic field sensor comprises: a substrate, a magnetic flux conversion module, a magnetic induction module and an output module; The magnetic flux conversion module is arranged inside the groove of the substrate or above the substrate; the magnetic flux conversion module is used to modulate the magnetic field to be measured to generate a magnetic field component in the X-axis direction to form a target magnetic flux path; wherein the direction of the magnetic field to be measured is the Z-axis direction; The magnetic induction module includes at least two magnetic induction units; the magnetic induction units are arranged between the magnetic flux conversion modules along the Z-axis direction, and the magnetic induction units are used to generate differential voltage signals under the action of the target magnetic flux path; wherein the magnetic induction units are composed of at least one magnetoresistive sensitive element, and the sensitivity directions of the magnetic induction units are the same; The magnetic induction module uses at least one structure of a differential full bridge, a differential half bridge, a push-pull full bridge, and a push-pull half bridge to sense the magnetic field of the magnetic flux conversion module, generates a differential voltage signal, and forms an output signal of the magnetic field to be measured through the output module; The plane where the base is located is a plane formed by the X-axis and the Y-axis, the magnetic flux conversion module is arranged along the X-axis direction, and the plane perpendicular to the plane where the base is located is a plane where the Z-axis is located.

2. The Z-axis magnetic field sensor according to claim 1, characterized in that: The magnetic flux conversion module includes at least one first magnetic flux conversion unit and at least one second magnetic flux conversion unit; The first magnetic flux conversion unit and the second magnetic flux conversion unit are arranged on both sides of the magnetic induction unit along the Z-axis direction; the first magnetic flux conversion unit and the second magnetic flux conversion unit are used to concentrate and amplify the magnetic field to be measured to form the target magnetic flux path, and generate a magnetic field component in the X-axis direction at the interval position between the first magnetic flux conversion unit and the second magnetic flux conversion unit; The projections of the first magnetic flux conversion unit and the second magnetic flux conversion unit on the X-axis do not overlap or the overlapping portion is smaller than an overlapping threshold.

3. The Z-axis magnetic field sensor according to claim 2, characterized in that: The substrate comprises a first substrate and a second substrate; The first magnetic flux conversion unit is disposed in the groove of the first substrate, and the second magnetic flux conversion unit is disposed in the groove of the second substrate.

4. The Z-axis magnetic field sensor according to claim 3, characterized in that: The magnetic induction unit includes at least one first magnetic induction unit and at least one second magnetic induction unit; The first magnetic induction unit and the second magnetic induction unit are arranged along the Z-axis direction, so that the first magnetic induction unit and the second magnetic induction unit are respectively located in planes formed by two different X-axis and Y-axis; The first magnetic induction unit is integrated on the first substrate, and the second magnetic induction unit is integrated on the second substrate; the sensitivity directions of the first magnetic induction unit and the second magnetic induction unit are the same or different.

5. The Z-axis magnetic field sensor according to claim 2, characterized in that: The magnetic flux conversion module also includes a magnetic flux connection unit; The magnetic flux connection unit is arranged between the first magnetic flux conversion unit and the second magnetic flux conversion unit; wherein the material of the magnetic flux connection unit is a metallic soft magnetic material; The metal soft magnetic material of the magnetic flux connection unit is distributed along the X-axis direction, connecting the magnetic flux paths of the first magnetic flux conversion unit and the second magnetic flux conversion unit and guiding them along the direction parallel to the X-axis; The magnetic induction unit is arranged inside the metal soft magnetic material of the magnetic flux connection unit or in the gap between the metal soft magnetic materials of the magnetic flux conversion module.

6. A Z-axis magnetic field sensor according to claim 2, characterized in that: The magnetic flux conversion module also includes an enhanced magnetic flux conversion unit; The enhanced magnetic flux conversion unit is superimposed on the first magnetic flux conversion unit and / or the second magnetic flux conversion unit in the Z-axis direction to further focus and amplify the magnetic field to be measured.

7. The Z-axis magnetic field sensor according to claim 1, characterized in that: The magnetic induction units are respectively composed of at least one magnetoresistance sensitive element connected in series and in parallel; wherein the magnetoresistance sensitive element is any one of anisotropic magnetoresistance AMR, giant magnetoresistance GMR, and tunnel magnetoresistance TMR.

8. The Z-axis magnetic field sensor according to claim 1, characterized in that: The output module includes an open-loop signal conditioning circuit, or a closed-loop signal conditioning circuit and a magnetic field feedback coil; The open-loop signal conditioning circuit performs conditioning, amplification, temperature compensation and linearity correction on the differential voltage signal to form an output signal of the Z-axis magnetic field sensor; The closed-loop signal conditioning circuit, the magnetic field feedback coil and the magnetic induction unit constitute a closed-loop magnetic field feedback structure; after the differential voltage signal is amplified by the closed-loop signal conditioning circuit, a feedback magnetic field is generated through the magnetic field feedback coil to achieve a dynamic balance of the magnetic field; the feedback current of the magnetic field feedback coil is sampled to form the output signal of the Z-axis magnetic field sensor.

9. The Z-axis magnetic field sensor according to claim 1, characterized in that: The Z-axis magnetic field sensor also includes a lead pad and a mechanical support housing; the manufacturing process adopted by the Z-axis magnetic field sensor is single-chip integration.

10. A method for processing a Z-axis magnetic field sensor, characterized in that: The processing method is used to process a Z-axis magnetic field sensor including a substrate, a magnetic flux conversion module and a magnetic induction module; the magnetic induction module includes at least two magnetic induction units; the magnetic flux conversion module includes at least one first magnetic flux conversion unit and at least one second magnetic flux conversion unit; the processing method includes: Depositing a MR magnetoresistive film on the surface of the substrate and processing it to form the magnetic sensing unit; Depositing a passivation layer on the surface of the substrate on which the magnetic sensing unit is deposited; wherein the passivation layer is used to protect the magnetic sensing unit; One or more grooves are formed on the substrate along the X-axis direction and spaced apart from each other, and a high magnetic permeability metal soft magnetic material is deposited in the groove to form a first magnetic flux conversion unit in the magnetic flux conversion module; Forming one or more spaced-distributed metal soft magnetic materials on the substrate passivation layer by deposition and semiconductor micromachining to form a second magnetic flux conversion unit in the magnetic flux conversion module; The first magnetic flux conversion unit and the second magnetic flux conversion unit are evenly arranged on both sides of the magnetic induction unit; wherein the projections of the first magnetic flux conversion unit and the second magnetic flux conversion unit on the X-axis do not overlap or the overlapping part is smaller than the overlapping threshold; Among them, the magnetic flux conversion module is used to modulate the magnetic field to be measured in the Z-axis direction, and generate a magnetic field component in the X-axis direction to form a target magnetic flux path; the magnetic induction unit is used to generate a differential voltage signal under the action of the target magnetic flux path; the plane where the substrate is located is the plane formed by the X-axis and the Y-axis, and the magnetic flux conversion module is arranged along the X-axis direction, and the plane perpendicular to the plane where the substrate is located is the plane where the Z-axis is located.

11. The processing method according to claim 10, characterized in that: The groove is formed on the substrate by using a reverse DRIE deep reactive ion etching process, wherein the groove opening is located on a side of the substrate away from the MR magnetoresistive film; After the metal soft magnetic material is deposited, it is polished using a CMP chemical mechanical polishing process.

12. The processing method according to any one of claims 10-11, characterized in that: On the surface where the MR magnetoresistive film is located and / or on the surface of the substrate adjacent to the MR magnetoresistive film, one or more metal soft magnetic materials are deposited and distributed at intervals along the X-axis direction to form a magnetic flux connection unit.

13. The processing method according to any one of claims 10-11, characterized in that: On the second magnetic flux conversion unit formed by depositing a metal soft magnetic material on the surface of the substrate away from the MR magnetoresistive film and / or on the surface of the substrate where the MR magnetoresistive film is located, an enhanced magnetic flux conversion unit is stacked along the Z-axis direction.

14. The processing method according to any one of claims 10-11, characterized in that: The MR magnetoresistive film includes anisotropic magnetoresistance AMR, giant magnetoresistance GMR or tunnel magnetoresistance TMR.

15. The processing method according to any one of claims 10-11, characterized in that: The Z-axis magnetic field sensor is packaged in a single chip by using WLP wafer-level packaging and TSV through-silicon via technology, with lead pads and circuits attached to form a single chip.

16. A Z-axis magnetic field sensor processing method, characterized in that: The processing method is used to process a Z-axis magnetic field sensor including a substrate, a magnetic flux conversion module and a magnetic induction module; the magnetic induction module includes at least two magnetic induction units; the magnetic flux conversion module includes at least one first magnetic flux conversion unit and at least one second magnetic flux conversion unit; the Z-axis magnetic field sensor processing method includes: Forming one or more spaced-apart metal soft magnetic materials on the substrate by deposition and semiconductor micromachining to form the first magnetic flux conversion unit, polishing by CMP chemical mechanical polishing process and depositing a passivation layer; Depositing an MR magnetoresistive film on the surface of the passivation layer to form the magnetic sensing unit through processing; After depositing a passivation layer again on the magnetic induction unit, one or more spaced-apart metal soft magnetic materials are formed by deposition and semiconductor micromachining to form the second magnetic flux conversion unit; The first magnetic flux conversion unit and the second magnetic flux conversion unit are evenly arranged on both sides of the magnetic induction unit; wherein the projections of the first magnetic flux conversion unit and the second magnetic flux conversion unit on the X-axis do not overlap or the overlapping part is smaller than the overlapping threshold; Among them, the magnetic flux conversion module is used to modulate the magnetic field to be measured to generate a magnetic field component in the X-axis direction to form a target magnetic flux path; the magnetic induction unit is used to generate a differential voltage signal under the action of the target magnetic flux path; the plane where the substrate is located is the plane formed by the X-axis and the Y-axis, the magnetic flux conversion module is arranged along the X-axis direction, and the plane perpendicular to the plane where the substrate is located is the plane where the Z-axis is located.

17. The processing method according to claim 16, characterized in that: On the surface where the MR magnetoresistive film is located and / or on the surface of the substrate adjacent to the MR magnetoresistive film, one or more metal soft magnetic materials are deposited and distributed at intervals along the X-axis direction to form a magnetic flux connection unit.

18. The processing method according to claim 16, characterized in that: On the second magnetic flux conversion unit formed by depositing a metal soft magnetic material on the surface of the substrate away from the MR magnetoresistive film and / or on the surface of the substrate where the MR magnetoresistive film is located, an enhanced magnetic flux conversion unit is stacked along the Z-axis direction.

19. The processing method according to claim 16, characterized in that: The MR magnetoresistive film includes anisotropic magnetoresistance AMR, giant magnetoresistance GMR or tunnel magnetoresistance TMR.

20. The processing method according to claim 16, characterized in that: The Z-axis magnetic field sensor is packaged in a single chip by using WLP wafer-level packaging and TSV through-silicon via technology, with lead pads and circuits attached to form a single chip.

21. A Z-axis magnetic field sensor processing method, characterized in that: The processing method is used to process a Z-axis magnetic field sensor including a substrate, a magnetic flux conversion module and a magnetic induction module; the magnetic induction module includes at least two magnetic induction units; the magnetic flux conversion module includes at least one first magnetic flux conversion unit and at least one second magnetic flux conversion unit; the substrate includes a first substrate and a second substrate; the Z-axis magnetic field sensor processing method includes: Depositing an MR magnetoresistive film on the surface of the first substrate, processing to form the magnetic sensing unit, and depositing a passivation layer on the first substrate surface on which the magnetic sensing unit is deposited; Using a reverse DRIE deep reactive ion etching process on the first substrate, one or more grooves distributed at intervals are formed on a side of the first substrate away from the MR magnetoresistive film; Depositing a metal soft magnetic material in the groove and polishing it by using a CMP chemical mechanical polishing process to form a first magnetic flux conversion unit in the magnetic flux conversion module; The second substrate adopts the same process flow as the first substrate to form the magnetic induction unit and the second magnetic flux conversion unit, or does not deposit the MR magnetoresistive film, and the subsequent process flow is consistent with the first substrate, using a reverse DRIE process to form one or more spaced grooves, and depositing a metal soft magnetic material and then using a CMP process to form the second magnetic flux conversion unit; The WLP wafer-level packaging process is adopted, the first substrate and the second substrate are arranged opposite to each other along the Z-axis direction, and the first magnetic flux conversion unit and the second magnetic flux conversion unit are evenly arranged on both sides of the magnetic induction unit; wherein the projections of the first magnetic flux conversion unit and the second magnetic flux conversion unit on the X-axis do not overlap or the overlapping part is less than the overlapping threshold; The MR magnetoresistive film is located at an interval position between the first magnetic flux conversion unit and the second magnetic flux conversion unit in the X-axis direction; wherein the sensitivity direction of the MR magnetoresistive film located on the first substrate is the same, and the sensitivity direction of the MR magnetoresistive film located on the second substrate is the same; In the case where the second substrate includes a magnetic induction unit, after the first substrate and the second substrate are relatively packaged along the Z-axis direction, the sensitivity directions of the first magnetic induction unit and the second magnetic induction unit are parallel to the plane formed by the X-axis and the Y-axis.

22. The processing method according to claim 21, characterized in that: On the surface where the MR magnetoresistive film is located and / or on the surface of the substrate adjacent to the MR magnetoresistive film, one or more metal soft magnetic materials are deposited and distributed at intervals along the X-axis direction to form a magnetic flux connection unit.

23. The processing method according to claim 21, characterized in that: On the second magnetic flux conversion unit formed by depositing a metal soft magnetic material on the surface of the substrate away from the MR magnetoresistive film and / or on the surface of the substrate where the MR magnetoresistive film is located, an enhanced magnetic flux conversion unit is stacked along the Z-axis direction.

24. The processing method according to claim 21, characterized in that: The MR magnetoresistive film includes anisotropic magnetoresistance AMR, giant magnetoresistance GMR or tunnel magnetoresistance TMR.

25. The processing method according to claim 21, characterized in that: The Z-axis magnetic field sensor is packaged in a single chip by using WLP wafer-level packaging and TSV through-silicon via technology, with lead pads and circuits attached to form a single chip.

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