Micro magnetic sensor combined with electromagnetic induction and lorentz force and preparation method thereof

Abstract

The application discloses a micro magnetic sensor combined with electromagnetic induction and Lorentz force and a preparation method thereof. The sensor comprises a high-frequency resonance component, a low-frequency resonance component and a coupling beam between the two components. The high-frequency resonance component comprises a driving electrode, a high-frequency resonance structure, a first insulating layer on the side of the high-frequency resonance structure, a Lorentz force driving coil, a second insulating layer on the side of the high-frequency resonance structure, a metal shielding layer, a third insulating layer on the side of the high-frequency resonance structure and an electromagnetic induction coil. The low-frequency resonance component comprises an induction electrode, a low-frequency resonance structure, an insulating layer on the side of the low-frequency resonance structure and a metal coil. The application establishes a composite magnetic sensitive architecture of electrostatic driving-electromagnetic induction and Lorentz force driving-electrostatic sensitivity on the internal resonance coupling structure, so as to improve the magnetic sensing performance through the superposition of two types of magnetic sensitive output signals. Meanwhile, the low-frequency resonance amplitude amplification effect of internal resonance is utilized to realize that the low-frequency resonance structure plate capacitor serves as a magnetic sensing signal output, so as to reduce the power consumption of the Lorentz force type magnetic sensitive element.

Description

TECHNICAL FIELD

[0001] The present application relates to a micromechanical magnetic field sensor and a preparation method, in particular to a micro magnetic sensor and a preparation method of a composite of electromagnetic induction and Lorentz force. BACKGROUND

[0002] Magnetic field sensors are widely used in biomedical, aerospace, civil engineering, consumer electronics and other fields. It is a kind of device that converts external magnetic field into electrical signal through sensitive material or structure and processes it. The application scene of magnetic field sensor is very wide, so various sensors are generated, including but not limited to magnetic flux gate sensor, Hall effect sensor, superconducting quantum interference device, giant magnetoresistance sensor, anisotropic magnetoresistance sensor, etc. Since the 1990s of last century, with the development of micromachining technology, magnetic field sensors based on microelectromechanical systems (MEMS) technology have also emerged.

[0003] In recent years, researchers have proposed MEMS magnetic sensor technology based on Lorentz force principle and MEMS magnetic sensor technology based on electromagnetic induction principle. Lorentz force MEMS magnetic sensor is a coil made on a resonant structure. When the device works, the coil is powered with alternating current with the same frequency as the resonant frequency of the resonant structure. When the external magnetic field exists, the powered coil will be subjected to Lorentz force, thereby driving the resonant structure into resonance state, and the magnetic field sensing and measurement are realized by detecting the amplitude of the resonant structure. The sensitive technology based on electromagnetic induction principle is also based on a resonant structure with a coil. When the resonant structure is forced to vibrate, the coil on it will cut the magnetic force line of the external magnetic field, thereby generating an induced electromotive force proportional to the strength of the external magnetic field. Thus, the strength of the external magnetic field is measured by measuring the induced electromotive force. These two technologies have the advantages of simple material and fast response speed, and are widely used in the design and manufacture of various magnetic field sensors.

[0004] At present, there are many magnetic sensors based on the above technologies in the industry, such as electrostatic driving-electromagnetic induction MEMS magnetic sensor and Lorentz force driving-electrostatic sensitive MEMS magnetic sensor, etc. However, the research on micromechanical magnetic sensors of different principles is completely separated and lacks linkage, which restricts the potential of improving the performance of MEMS magnetic sensors. On the other hand, traditional Lorentz force magnetic sensors need to increase the excitation current to improve the Lorentz force and increase the amplitude of the microstructure, which leads to the increase of the device power consumption and the level of Joule heat effect in the square relationship of the current. SUMMARY

[0005] The micro magnetic sensor of the electromagnetic induction type and the Lorentz force type is prepared by establishing the MEMS composite magnetic sensitive architecture of the electrostatic drive-electromagnetic induction and the Lorentz force drive-static electric sensitive on the basis of the internal resonance coupling structure, the magnetic sensing performance is improved by the composite superposition of the two types of magnetic sensitive output signals, the amplitude of the low-frequency resonance structure is amplified by the mechanism of the internal resonance high-frequency resonance structure driving the low-frequency resonance structure coupling, the voltage signal converted by the charge variation of the inductive electrode is summed after the signal processing of the induced electromotive force output signal generated by the electromagnetic induction coil cutting the magnetic induction line and the direct current signal to reflect the external magnetic field intensity.

[0006] Another object of the present application is to provide a preparation method of the micro magnetic sensor of the electromagnetic induction type and the Lorentz force type.

[0007] The object of the present application is achieved by the following technical solutions.

[0008] The micro magnetic sensor of the electromagnetic induction type and the Lorentz force type comprises a high-frequency resonance assembly, a low-frequency resonance assembly and a coupling beam coupled between the high-frequency resonance assembly and the low-frequency resonance assembly.

[0009] The high-frequency resonance assembly comprises a driving electrode, a high-frequency resonance structure and a high-frequency resonance structure side first insulating layer, a driving coil, a high-frequency resonance structure side second insulating layer, a metal shielding layer, a high-frequency resonance structure side third insulating layer and an electromagnetic induction coil arranged on the high-frequency resonance structure in sequence; the metal shielding layer is grounded through an external circuit to reduce the signal interference generated by the driving coil to the induction coil.

[0010] The low-frequency resonance assembly comprises an inductive electrode and a low-frequency resonance structure; the low-frequency resonance structure is connected with the high-frequency resonance structure through the coupling beam; the resonance frequency of the high-frequency resonance structure and the resonance frequency of the low-frequency resonance structure have an integer ratio relationship and the frequency ratio is greater than or equal to 2:1.

[0011] In the working state, the inductive magnetic field mode of the high-frequency resonance structure is excited to the critical nonlinear state by the electrostatic drive, at this time, the electrostatic drive signal frequency is equal to the inductive magnetic field mode resonance frequency of the high-frequency resonance structure, the alternating current with the same frequency and phase as the electrostatic drive is input into the driving coil, the Lorentz force is generated under the action of the external magnetic field, the high-frequency resonance structure is forced to enter the nonlinear state and the energy is transferred to the low-frequency resonance structure; finally, the sum of the direct current signals obtained after the signal processing of the induced electromotive force output signal generated by the electromagnetic induction coil cutting the magnetic induction line and the voltage signal converted by the charge variation of the inductive electrode is calculated to reflect the external magnetic field intensity.

[0012] Further, the electromagnetic induction coil, the Lorentz force driving coil and the metal coil can be single-layer, multi-layer, single-turn or multi-turn.

[0013] In one preferred embodiment of the present application, the resonant modes of the high-frequency resonant structure and the low-frequency resonant structure correspond to the same vibration mode, and are either torsional resonant modes or in-plane translational modes.

[0014] If the resonant modes are torsional modes, the driving electrode and the sensing electrode are arranged between the high-frequency resonant structure and the substrate sheet and between the low-frequency resonant structure and the substrate sheet, respectively.

[0015] If the resonant modes are in-plane translational modes, the driving electrode and the sensing electrode are arranged at any position around the high-frequency resonant structure and the low-frequency resonant structure suitable for driving and detecting the translational modes.

[0016] In one preferred embodiment of the present application, the driving electrode is single or multiple, and the driving mode of the driving electrode includes electrostatic differential driving, electrostatic single-side driving and other electrostatic driving modes.

[0017] In one preferred embodiment of the present application, the sensing electrode is single or multiple, and the driving mode of the sensing electrode includes electrostatic differential sensing, electrostatic single-side sensing and other electrostatic sensing modes.

[0018] In one preferred embodiment of the present application, the high-frequency resonant assembly and the low-frequency resonant assembly each further include an anchor point and a support beam.

[0019] The anchor point is arranged on the substrate.

[0020] One end of the support beam is fixedly connected to the anchor point, and the other end of the support beam is fixedly connected to the high-frequency resonant structure or the low-frequency resonant structure.

[0021] Further, the two ends of the coupling beam are respectively connected to the support beam corresponding to the high-frequency resonant assembly and the support beam corresponding to the low-frequency resonant assembly.

[0022] In one preferred embodiment of the present application, the low-frequency resonant assembly further includes an insulating layer and a metal coil, the low-frequency resonant structure side insulating layer is arranged on the low-frequency resonant structure, the metal coil is arranged on the low-frequency resonant structure side insulating layer, and the low-frequency insulating layer includes a low-frequency resonant structure side first insulating layer, a low-frequency resonant structure side second insulating layer and a low-frequency resonant structure side third insulating layer.

[0023] The metal coil includes a first layer of metal coil, a second layer of metal coil and a third layer of metal coil.

[0024] The low-frequency resonant structure side first insulating layer, the first layer of metal coil, the low-frequency resonant structure side second insulating layer, the second layer of metal coil, the low-frequency resonant structure side third insulating layer and the third layer of metal coil are sequentially arranged on the low-frequency resonant structure.

[0025] In one preferred scheme of the present application, in the working state, a DC voltage is applied to the high-frequency resonant structure and the low-frequency resonant structure; an AC voltage with the same frequency as the resonant frequency of the induced magnetic field mode of the high-frequency resonant structure is applied to the driving electrode, the high-frequency resonant structure vibrates under the action of electrostatic force and enters the critical nonlinear state; an AC current with the same frequency and phase as the driving electrode is applied to the driving coil; under the action of the external magnetic field, the high-frequency resonant structure is driven into the nonlinear state by the Lorentz force, and the electromagnetic induction coil cuts the magnetic induction lines of the external magnetic field to generate an induced electromotive force V1, which is output to the external circuit as part of the composite sensitive output signal.

[0026] After the high-frequency resonant structure enters the nonlinear state, part of the energy is transmitted to the low-frequency resonant structure through the coupling beam, so that the low-frequency resonant structure starts to vibrate and resonates according to the induced magnetic field mode; an AC current with the same frequency as the resonant frequency of the low-frequency resonant structure is applied to the metal coil on the low-frequency resonant structure; under the action of the external magnetic field, the low-frequency resonant structure is driven by the Lorentz force to increase the amplitude.

[0027] The inductive electrode and the low-frequency resonant structure form a capacitor, and the vibration of the low-frequency resonant structure causes the charge of the inductive electrode to change; the charge change of the inductive electrode is converted into a voltage signal V2 through a C-V conversion circuit, and V2 is output to the external circuit as part of the composite sensitive output signal; the electrical signals V1 and V2 are processed and converted into a DC signal and then summed, thereby reflecting the strength of the external magnetic field.

[0028] In one preferred scheme of the present application, in the working state, a DC voltage is applied to the high-frequency resonant structure and the low-frequency resonant structure; an AC voltage with the same frequency as the resonant frequency of the induced magnetic field mode of the high-frequency resonant structure is applied to the driving electrode, the high-frequency resonant structure vibrates under the action of electrostatic force and enters the critical nonlinear state; an AC current with the same frequency and phase as the driving electrode is applied to the driving coil; under the action of the external magnetic field, the high-frequency resonant structure is driven into the nonlinear state by the Lorentz force, and the electromagnetic induction coil cuts the magnetic induction lines of the external magnetic field to generate an induced electromotive force V1, which is output to the external circuit as part of the composite sensitive output signal.

[0029] After the high-frequency resonant structure enters the nonlinear state, part of the energy is transmitted to the low-frequency resonant structure through the coupling beam, so that the low-frequency resonant structure starts to vibrate and resonates according to the induced magnetic field mode;

[0030] The inductive electrode and the low-frequency resonance structure form a capacitor, vibration of the low-frequency resonance structure causes the charge amount of the inductive electrode to change; the C-V conversion circuit converts the charge amount change of the inductive electrode into a voltage signal V2, and outputs V2 as part of the composite sensitive output signal to the external circuit; meanwhile, the metal coil on the low-frequency resonance structure cuts the magnetic induction lines of the external magnetic field to generate an induced electromotive force V3, and outputs V3 as part of the composite sensitive output signal to the external circuit; the electrical signals V1, V2 and V3 are processed and converted into direct current signals and then summed, thereby reflecting the strength of the external magnetic field.

[0031] A preparation method of an electromagnetic induction type and Lorentz force type composite micro magnetic sensor, comprising the following steps:

[0032] (1) providing a substrate sheet, depositing a metal layer on one side of the substrate through a deposition process; defining a metal layer pattern through photolithography and etching the metal layer to form a drive electrode and an inductive electrode on the substrate;

[0033] (2) providing a structure sheet, defining a cavity pattern on the structure sheet through photolithography and etching a V-shaped cavity;

[0034] (3) aligning the substrate sheet with the structure sheet and performing wafer bonding; the drive electrode and the inductive electrode are located in the cavity of the structure sheet;

[0035] (4) thinning the structure sheet to a certain thickness through a wafer thinning process;

[0036] (5) depositing an insulating layer on the structure sheet, defining an insulating layer pattern through photolithography, and etching the insulating layer to form a high-frequency resonance structure side first insulating layer;

[0037] (6) depositing a metal layer on the surface of the above structure, defining a metal layer pattern through photolithography, and etching the metal layer to form a drive coil; the drive coil is located above the high-frequency resonance structure side first insulating layer;

[0038] (7) depositing an insulating layer on the surface of the above structure, defining an insulating layer pattern through photolithography, and etching the insulating layer to form a high-frequency resonance structure side second high-frequency insulating layer; the high-frequency resonance structure side second high-frequency insulating layer is located above the drive coil;

[0039] (8) depositing a metal layer on the surface of the above structure, defining a metal layer pattern through photolithography, and etching the metal layer to form a metal shielding layer; the metal shielding layer is located above the high-frequency resonance structure side second high-frequency insulating layer;

[0040] (9) depositing an insulating layer on the structure surface, defining the insulating layer pattern by photolithography, and etching the insulating layer to form a third high-frequency insulating layer on the side of the high-frequency resonant structure; the third high-frequency insulating layer is located above the metal shielding layer;

[0041] (10) depositing a metal layer on the structure surface, defining the metal layer pattern by photolithography, and etching the metal layer to form an electromagnetic induction coil; the electromagnetic induction coil is located above the third high-frequency insulating layer on the side of the high-frequency resonant structure;

[0042] (11) defining the etching pattern of the structure piece by photolithography, and etching the structure piece to release the movable structure, forming the high-frequency resonant structure and the low-frequency resonant structure connected by the coupling beam.

[0043] A preparation method of a micro magnetic sensor combined with electromagnetic induction and Lorentz force, comprising the following steps:

[0044] (1) providing a substrate piece, depositing a metal layer on one side of the substrate by a deposition process; defining the metal layer pattern by photolithography and etching the metal layer to form a driving electrode and a sensing electrode on the substrate;

[0045] (2) providing a structure piece, defining the cavity pattern by photolithography and etching a V-shaped cavity on the structure piece;

[0046] (3) aligning the substrate piece with the structure piece and performing wafer bonding; the driving electrode and the sensing electrode are located in the cavity of the structure piece;

[0047] (4) thinning the structure piece to a certain thickness by wafer thinning process;

[0048] (5) depositing an insulating layer on the structure piece, defining the insulating layer pattern by photolithography, and etching the insulating layer to form a first insulating layer on the side of the high-frequency resonant structure and a first insulating layer on the side of the low-frequency resonant structure;

[0049] (6) depositing a metal layer on the structure surface, defining the metal layer pattern by photolithography, and etching the metal layer to form a driving coil and a first layer metal coil; the driving coil is located above the first insulating layer on the side of the high-frequency resonant structure; the first layer metal coil is located above the first insulating layer on the side of the low-frequency resonant structure;

[0050] (7) depositing an insulating layer on the structure surface, defining the insulating layer pattern by photolithography, and etching the insulating layer to form a second high-frequency insulating layer on the side of the high-frequency resonant structure and a second insulating layer on the side of the low-frequency resonant structure; the second high-frequency insulating layer is located above the driving coil; the second insulating layer on the side of the low-frequency resonant structure is located above the first layer metal coil;

[0051] (8) depositing a metal layer on the surface of the structure, and defining a metal layer pattern by photolithography, and etching the metal layer to form a metal shielding layer and a second layer of metal coil; the metal shielding layer is above the second high-frequency insulating layer on the side of the high-frequency resonant structure; the second layer of metal coil is above the second insulating layer on the side of the low-frequency resonant structure;

[0052] (9) depositing an insulating layer on the surface of the structure, and defining an insulating layer pattern by photolithography, and etching the insulating layer to form a third high-frequency insulating layer on the side of the high-frequency resonant structure and a third insulating layer on the side of the low-frequency resonant structure; the third high-frequency insulating layer on the side of the high-frequency resonant structure is above the metal shielding layer; the third insulating layer on the side of the low-frequency resonant structure is above the second layer of metal coil;

[0053] (10) depositing a metal layer on the surface of the structure, and defining a metal layer pattern by photolithography, and etching the metal layer to form an electromagnetic induction coil and a third layer of metal coil; the electromagnetic induction coil is above the third high-frequency insulating layer on the side of the high-frequency resonant structure; the third layer of metal coil is above the third insulating layer on the side of the low-frequency resonant structure;

[0054] (11) defining an etching pattern by photolithography on the structure piece, and etching the structure piece to release the movable structure, and forming the high-frequency resonant structure and the low-frequency resonant structure connected by the coupling beam.

[0055] Compared with the prior art, the present application has the following beneficial effects:

[0056] 1. The present application reduces the current applied to the drive coil and reduces energy consumption by combining electrostatic driving and Lorentz force driving.

[0057] 2. Based on the internal resonance principle, after the high-frequency resonant structure enters the nonlinear state, the excess energy is transmitted to the low-frequency resonant structure, and the low-frequency resonant structure generates a larger amplitude, thereby improving the performance of the device or reducing energy consumption.

[0058] 3. A metal shielding layer connected to the ground through an external circuit is deposited between the drive coil and the induction coil, effectively reducing the signal interference generated by the drive coil on the induction coil. BRIEF DESCRIPTION OF DRAWINGS

[0059] Figure 1 The working principle diagram of the electromagnetic induction and Lorentz force combined sensitive micro-mechanical magnetic field sensor of the present application is shown.

[0060] Figure 2 The top view structural schematic diagram of the first embodiment of the electromagnetic induction and Lorentz force combined micro magnetic sensor of the present application is shown.

[0061] Figure 3Fig. 1 is a schematic diagram showing the working principle of the first embodiment of the micro magnetic sensor of the electromagnetic induction type and the Lorentz force type according to the present application.

[0062] Figure 4 Fig. 2 is a sectional view of the first embodiment of the micro magnetic sensor of the electromagnetic induction type and the Lorentz force type according to the present application.

[0063] Figure 5 Fig. 3 is a schematic diagram showing the working principle of the second embodiment of the micro magnetic sensor of the electromagnetic induction type and the Lorentz force type according to the present application.

[0064] Figure 6 Fig. 4 is a sectional view of the second embodiment of the micro magnetic sensor of the electromagnetic induction type and the Lorentz force type according to the present application.

[0065] Figure 7 Fig. 5 is a schematic diagram showing the working principle of the third embodiment of the micro magnetic sensor of the electromagnetic induction type and the Lorentz force type according to the present application.

[0066] Figure 8 Fig. 6 is a sectional view of the third embodiment of the micro magnetic sensor of the electromagnetic induction type and the Lorentz force type according to the present application.

[0067] Figures 9-19 Fig. 7 is a schematic diagram showing the working principle of the fourth embodiment of the micro magnetic sensor of the electromagnetic induction type and the Lorentz force type according to the present application.

[0068] Element number explanation:

[0069] 1311, driving electrode 1

[0070] 1312, driving electrode 2

[0071] 1321, sensing electrode 1

[0072] 1322, sensing electrode 2

[0073] 14, substrate piece

[0074] 210, structure piece

[0075] 2111, high-frequency resonance structure

[0076] 2112, support beam 1

[0077] 2113, anchor point 1

[0078] 2121, low-frequency resonance structure

[0079] 2122, support beam 2

[0080] 2123, anchor point 2

[0081] 213, coupling beam

[0082] 2211, first insulating layer on high-frequency resonance structure side

[0083] 2212, second high-frequency insulating layer on high-frequency resonance structure side

[0084] 2213, third high-frequency insulating layer on high-frequency resonance structure side

[0085] 2221, first insulating layer on low-frequency resonance structure side

[0086] 2222, second insulating layer on low-frequency resonance structure side

[0087] 2223, third insulating layer on low-frequency resonance structure side

[0088] 2311, drive coil

[0089] 2312, metal shielding layer

[0090] 2313, electromagnetic induction coil

[0091] 2314, pad 1

[0092] 2321, first layer metal coil

[0093] 2322, second layer metal coil

[0094] 2323, third layer metal coil

[0095] 2324, pad 2

[0096] 240, cavity DETAILED DESCRIPTION

[0097] In order for those skilled in the art to have a better understanding of the technical solutions of the present application, the present application will be further described below in conjunction with the embodiments and drawings, but the embodiments of the present application are not limited thereto.

[0098] Example 1

[0099] Reference Figures 2-4The micro magnetic sensor combined with electromagnetic induction and Lorentz force in the embodiment comprises a high-frequency resonance component, a low-frequency resonance component, and a coupling beam 213 coupled between the high-frequency resonance component and the low-frequency resonance component; the high-frequency resonance component comprises two drive electrodes (1311 and 1312), a high-frequency resonance structure 2111, and a high-frequency resonance structure side first insulating layer 2211, a drive coil 2311, a high-frequency resonance structure side second high-frequency insulating layer 2212, a metal shielding layer 2312, a high-frequency resonance structure side third high-frequency insulating layer 2213, and an electromagnetic induction coil 2313 arranged on the high-frequency resonance structure 2111 in sequence; the drive electrodes (1311 and 1312) are arranged between the high-frequency resonance structure 2111 and a substrate; specifically, the drive mode of the drive electrodes (1311 and 1312) comprises electrostatic differential driving, electrostatic single-side driving, and other electrostatic driving modes.

[0100] Referring to Figures 2-4 The low-frequency resonance component comprises two sensing electrodes (1321 and 1322) and a low-frequency resonance structure 2121; the sensing electrodes (1321 and 1322) are arranged between the low-frequency resonance structure 2121 and the substrate; the resonance frequency of the high-frequency resonance structure 2111 and the resonance frequency of the low-frequency resonance structure 2121 have an integer ratio relationship; specifically, the drive mode of the sensing electrodes (1321 and 1322) comprises electrostatic differential sensing, electrostatic single-side sensing, and other electrostatic sensing modes. Specifically, the high-frequency resonance structure 2111 is a high-frequency torsion plate, and the low-frequency resonance structure 2121 is a low-frequency torsion plate.

[0101] Specifically, the number of turns of the electromagnetic induction coil 2313 is at least one, and the number of layers of the electromagnetic induction coil 2313 is at least one. Further, the electromagnetic induction coil 2313 is a multi-layer structure, the number of turns of each layer of the electromagnetic induction coil 2313 is multiple, and the winding direction is counterclockwise from outside to inside or clockwise from outside to inside.

[0102] Specifically, the number of turns of the drive coil 2311 is at least one, and the number of layers of the drive coil 2311 is at least one. Further, the drive coil 2311 is a multi-layer structure, the number of turns of each layer of the drive coil 2311 is multiple, and the winding direction is counterclockwise from outside to inside or clockwise from outside to inside.

[0103] Referring to Figures 1-4 The working principle of the micro magnetic sensor combined with electromagnetic induction and Lorentz force in the embodiment is as follows:

[0104] First, a DC voltage is applied to the high-frequency torsion plate (high-frequency resonant structure 2111) and the low-frequency torsion plate (low-frequency resonant structure 2121), and then an AC driving voltage of opposite phases is applied to the two driving electrode plates 1311 and 1312, and the frequency of the AC voltage is the same as the resonant frequency of the high-frequency torsion plate. The high-frequency torsion plate vibrates under the action of electrostatic force and enters a critical nonlinear state. Then an AC current of the same frequency and phase as the driving electrode plate 1311 is applied to the high-frequency resonant structure Lorentz force driving coil, and in the presence of an external magnetic field, the high-frequency torsion plate will be subjected to the action of Lorentz force and enter a nonlinear state, at which time the high-frequency torsion plate amplitude saturates. Then the high-frequency resonant structure electromagnetic induction coil 2313 cuts the magnetic induction lines of the external magnetic field to generate an induced electromotive force V1, which is related to the amplitude of the high-frequency torsion plate and reflects the strength of the external magnetic field. V1 is output as part of the composite sensitive output signal to the external circuit. After the high-frequency torsion plate enters the nonlinear state, it will trigger internal resonance phenomenon and cause energy to be transmitted through the coupling beam 213, and the low-frequency torsion plate 2121 starts to vibrate after receiving the transmitted energy. The induction electrodes 1321 and 1322 form a capacitor with the low-frequency torsion plate 2121, so that the vibration of the low-frequency torsion plate 2121 will cause the charge quantity of the induction electrode to change, and the change quantity is related to the amplitude of the low-frequency torsion plate 2121 and reflects the strength of the external magnetic field. The change in the charge quantity of the induction electrode plate 1321 can be converted into a voltage signal V21 through a C-V conversion circuit, and the change in the charge quantity of the induction electrode plate 1322 can be converted into a voltage signal V22 through the same method. The voltage signals V21 and V22 are subjected to differential operation to obtain a voltage signal V2, and V2 is output as part of the composite sensitive output signal to the external circuit. The electrical signals V1 and V2 are processed and added to reflect the strength of the external magnetic field.

[0105] Example 2

[0106] Reference Figures 5-6 Unlike Example 1, the low-frequency resonant assembly of the present embodiment further comprises a low-frequency resonant structure side insulating layer and a metal coil; the low-frequency resonant structure side insulating layer is arranged on the low-frequency resonant structure 2121; the metal coil is arranged on the low-frequency resonant structure side insulating layer; the low-frequency resonant structure side insulating layer comprises a low-frequency resonant structure side first insulating layer 2221, a low-frequency resonant structure side second insulating layer 2222 and a low-frequency resonant structure side third insulating layer 2223; the metal coil comprises a first layer metal coil 2321, a second layer metal coil 2322 and a third layer metal coil 2323; the low-frequency resonant structure side first insulating layer 2221, the first layer metal coil 2321, the low-frequency resonant structure side second insulating layer 2222, the second layer metal coil 2322, the low-frequency resonant structure side third insulating layer 2223 and the third layer metal coil 2323 are arranged on the low-frequency resonant structure 2121 in sequence.

[0107] Referring to Figures 5-6 The high-frequency resonant assembly and the low-frequency resonant assembly each further include an anchor point (2113 and 2123) and a support beam (2112 and 2122); the anchor point (2113 and 2123) is arranged on the substrate 14; one end of the support beam (2112 and 2122) is fixedly connected with the anchor point (2113 and 2123), and the other end of the support beam (2112 and 2122) is fixedly connected with the high-frequency resonant structure 2111 or the low-frequency resonant structure 2121.

[0108] Further, two ends of the coupling beam 213 are respectively connected on the support beam 2112 corresponding to the high-frequency resonant assembly and the support beam 2122 corresponding to the low-frequency resonant assembly.

[0109] Referring to Figures 5-6 The high-frequency resonant assembly and the low-frequency resonant assembly each further include two pads (2314 and 2324); the pads (2314 and 2324) are arranged on the anchor point (2113 and 2123).

[0110] Referring to Figures 5-6In the working state, firstly, a DC voltage is applied to the high-frequency torsion plate (high-frequency resonant structure 2111) and the low-frequency torsion plate (low-frequency resonant structure 2121), and then the two driving electrode plates 1311 and 1312 are applied with AC driving voltages which are opposite to each other, and the frequency of the AC voltage is the same as the resonant frequency of the high-frequency torsion plate. The high-frequency torsion plate vibrates under the action of electrostatic force and enters the critical nonlinear state. Then an AC current with the same frequency and phase as the electrode plate 1311 is applied to the high-frequency resonant structure Lorentz force driving coil, and in the presence of an external magnetic field, the high-frequency torsion plate will be driven by the Lorentz force to enter the nonlinear state, at which time the high-frequency torsion plate amplitude saturates. Then the high-frequency resonant structure electromagnetic induction coil 2313 cuts the magnetic induction lines of the external magnetic field to generate an induced electromotive force VI, which is related to the amplitude of the high-frequency torsion plate and reflects the strength of the external magnetic field. VI is output as part of the composite sensitive output signal to the external circuit. After the high-frequency torsion plate enters the nonlinear state, it will trigger internal resonance phenomenon and cause energy to be transmitted through the coupling beam 213, and the low-frequency torsion plate starts to vibrate after receiving the transmitted energy. At this time, an AC current Ia2 with the same frequency as the resonant frequency of the low-frequency torsion plate is applied to the coil on the low-frequency torsion plate. In the presence of an external magnetic field, the low-frequency torsion plate will be driven by the Lorentz force to cause the amplitude to increase. The induction electrodes 1321 and 1322 form a capacitor with the low-frequency torsion plate, so that the vibration of the low-frequency torsion plate will cause the charge quantity of the induction electrode to change, and the change quantity is related to the amplitude of the low-frequency torsion plate and reflects the strength of the external magnetic field. The charge quantity change of the induction electrode plate 1321 can be converted into a voltage signal V21 through a C-V conversion circuit, and the charge quantity change of the induction electrode plate 1322 can be converted into a voltage signal V22 through the same method. The voltage signals V21 and V22 are differentially operated to obtain a voltage signal V2, and V2 is output as part of the composite sensitive output signal to the external circuit. The electrical signals VI and V2 are processed and added to reflect the strength of the external magnetic field.

[0111] Example 3

[0112] Reference Figure 1 and Figures 7-8Unlike the embodiment 1, in the working state, a DC voltage is first applied to the high frequency torsional plate (high frequency resonant structure 2111) and the low frequency torsional plate (low frequency resonant structure 2121), and then the two driving electrode plates 1311 and 1312 are applied with alternating driving voltage with opposite phases, and the frequency of the alternating voltage is the same as the resonant frequency of the high frequency torsional plate. The high frequency torsional plate vibrates under the action of electrostatic force and enters the critical nonlinear state. Then an alternating current with the same frequency and phase as the electrode plate 1311 is applied to the high frequency resonant structure Lorentz force driving coil, and in the presence of an external magnetic field, the high frequency torsional plate will be subjected to the action of Lorentz force and enter the nonlinear state, at which time the high frequency torsional plate amplitude saturates. Then the high frequency resonant structure electromagnetic induction coil 2313 cuts the magnetic induction lines of the external magnetic field to generate an induced electromotive force VI, which is related to the amplitude of the high frequency torsional plate and reflects the strength of the external magnetic field. VI is output as part of the composite sensitive output signal to the external circuit. After the high frequency torsional plate enters the nonlinear state, it will trigger the internal resonance phenomenon and cause energy to be transmitted through the coupling beam 213, and the low frequency torsional plate starts to vibrate after receiving the transmitted energy. The inductive electrodes 1321 and 1322 form a capacitor with the low frequency torsional plate, so that the vibration of the low frequency torsional plate will cause the charge quantity of the inductive electrodes to change, and the change quantity is related to the amplitude of the low frequency torsional plate and reflects the strength of the external magnetic field. The charge quantity change of the inductive electrode plate 1321 can be converted into a voltage signal V21 through a C-V conversion circuit, and the charge quantity change of the inductive electrode plate 1322 can be converted into a voltage signal V22 through the same method. The voltage signals V21 and V22 are subjected to differential operation to obtain a voltage signal V2, and V2 is output as part of the composite sensitive output signal to the external circuit. At the same time, the coil on the low frequency torsional plate cuts the magnetic induction lines of the external magnetic field to generate an induced electromotive force V3, and V3 is output as part of the composite sensitive output signal to the external circuit. The electrical signals VI, V2 and V3 are processed and added to reflect the strength of the external magnetic field.

[0113] Embodiment 4

[0114] Referring to Figures 9-19 The preparation method of the electromagnetic induction type and Lorentz force type composite micro magnetic sensor of the embodiment includes the following steps:

[0115] (1) A substrate sheet 14 (such as glass) is provided, and a metal layer (such as aluminum) is deposited on one side of the substrate through a metal sputtering process. Then the metal layer pattern is defined by photolithography, and the metal layer is etched by wet etching method to form driving electrodes 1311 and 1312 and inductive electrodes 1321 and 1322 on the surface of the substrate. The side of the substrate sheet 14 with the metal structure is defined as the first surface, and the other side is the second surface, such as Figure 9 .

[0116] (2) Provide a structure piece 210 (such as a (100) surface silicon wafer), define a cavity pattern on one side of the structure silicon wafer by lithography, and etch a V-shaped cavity 240 on one side of the structure piece 210 by a wet etching process using an etchant (such as KOH), define the side of the structure piece 210 with the cavity 240 as the first surface, and the other side as the second surface, such as Figure 10 .

[0117] (3) Align the substrate piece 14 with the structure piece 210 and then bond by an anodic bonding technique, wherein the surfaces to be bonded with each other are the first surface of the substrate piece and the first surface of the structure piece, so that after bonding, the drive electrodes 1311 and 1312 and the sense electrodes 1321 and 1322 are placed in the cavity 240 of the structure piece, such as Figure 11 .

[0118] (4) Etch the second surface of the structure piece 210 using an etchant (such as KOH) to perform a thinning operation on the structure piece 210, such as Figure 12 .

[0119] (5) Deposit an insulating layer (such as silicon oxide) on the second surface of the structure piece 210 by chemical vapor deposition, define the insulating layer pattern by lithography, and etch the insulating layer to form the first insulating layer 2211 on the high-frequency resonance structure side and the first insulating layer 2221 on the low-frequency resonance structure side by reactive ion etching, such as Figure 12 .

[0120] (6) Deposit a metal layer (such as aluminum) on the above structure surface by metal sputtering process, define the metal layer pattern by lithography, and perform wet etching on the metal layer to form the drive coil 2311 and the first layer of metal coil 2321, such as Figure 14 .

[0121] (7) Deposit an insulating layer (such as silicon oxide) on the above structure surface by chemical vapor deposition, define the insulating layer pattern by lithography, and etch the insulating layer to form the second high-frequency insulating layer 2212 on the high-frequency resonance structure side and the second insulating layer 2222 on the low-frequency resonance structure side by reactive ion etching, such as Figure 15 .

[0122] (8) Deposit a metal layer (such as aluminum) on the above structure surface by metal sputtering process, define the metal layer pattern by lithography, and perform wet etching on the metal layer to form the metal shielding layer 2312 and the second layer of metal coil 2322, such as Figure 16 .

[0123] (9) Deposit an insulating layer (such as silicon oxide) on the above structure surface by chemical vapor deposition, define the insulating layer pattern by lithography, and etch the insulating layer to form the third high-frequency insulating layer 2213 on the high-frequency resonance structure side and the third insulating layer 2223 on the low-frequency resonance structure side by reactive ion etching, such asFigure 17 .

[0124] (10) In the above-mentioned structure surface, a metal layer (such as aluminum) is deposited by a metal sputtering process, a photoetching is used to define the pattern of the insulating layer, and a wet etching is used to form the electromagnetic induction coil 2313 and the third layer metal coil 2323, as shown in Fig. 23C. Figure 18 .

[0125] (11) A photoetching is used to define the etching pattern of the structure piece 210, and then a deep reactive ion etching technology is used to etch the structure piece 210 to release the movable structure, i.e. to form the high-frequency resonant structure 2111 and the low-frequency resonant structure 2121 connected by the coupling beam, as shown in Fig. 24C. Figure 19 .

[0126] The above is the preferred embodiment of the present application, but the embodiments of the present application are not limited by the above, and any changes, modifications, substitutions, combinations, simplifications made without departing from the spirit and principles of the present application shall be equivalent replacement methods and shall be included in the protection scope of the present application.

Claims

1. A micro magnetic sensor combining electromagnetic induction and Lorentz force, characterized in that: It includes a high-frequency resonant component, a low-frequency resonant component, and a coupling beam coupled between the high-frequency resonant component and the low-frequency resonant component; The high-frequency resonance component includes a driving electrode, a high-frequency resonance structure, and a first insulating layer on the high-frequency resonance structure side, a driving coil, a second insulating layer on the high-frequency resonance structure side, a metal shielding layer, a third insulating layer on the high-frequency resonance structure side, and an electromagnetic induction coil. The metal shielding layer is grounded through an external circuit to reduce signal interference generated by the driving coil on the induction coil. The low-frequency resonance component includes an induction electrode and a low-frequency resonance structure; The low-frequency resonant structure and the high-frequency resonant structure are connected via the coupling beam; the resonant frequency of the high-frequency resonant structure and the resonant frequency of the low-frequency resonant structure are in an integer ratio relationship, and the frequency ratio is greater than or equal to 2:1; In the working state, electrostatic drive is used to excite the induced magnetic field mode of the high-frequency resonant structure to a critical nonlinear state. At this time, the frequency of the electrostatic drive signal is equal to the resonant frequency of the induced magnetic field mode of the high-frequency resonant structure. Then, an alternating current with the same frequency and phase as the electrostatic drive is passed through the drive coil, so that it generates a Lorentz force under the action of the external magnetic field, forcing the high-frequency resonant structure to enter a nonlinear state and transfer energy to the low-frequency resonant structure; finally, the induced electromotive force output signal generated by cutting the magnetic flux lines of the electromagnetic induction coil and the voltage signal obtained by converting the charge change of the induction electrode are processed into DC signals and then summed to reflect the external magnetic field strength.

2. The electromagnetic induction and Lorentz force composite micro magnetic sensor according to claim 1, characterized in that: The low-frequency resonance component further includes a low-frequency resonance structure side insulation layer and a metal coil, wherein the low-frequency resonance structure side insulation layer is arranged on the low-frequency resonance structure; the metal coil is arranged on the low-frequency resonance structure side insulation layer; In the working state, a DC voltage is applied to the high-frequency resonant structure and the low-frequency resonant structure; An AC voltage having the same frequency as the modal resonant frequency of the induced magnetic field of the high-frequency resonant structure is applied to the driving electrode. The high-frequency resonant structure vibrates under the action of the electrostatic force and enters a critical nonlinear state. An AC current having the same frequency and phase as the driving electrode is applied to the driving coil. Under the action of the external magnetic field, the high-frequency resonant structure enters a nonlinear state due to the Lorentz force. The electromagnetic induction coil cuts the magnetic flux lines of the external magnetic field to generate an induced electromotive force V1, which is output to the external circuit as part of the composite sensitive output signal. After the high-frequency resonant structure enters the nonlinear state, part of the energy is transferred to the low-frequency resonant structure through the coupling beam, causing the low-frequency resonant structure to start vibrating and resonant motion according to the induced magnetic field mode; An alternating current having the same resonant frequency as the low-frequency resonant structure is applied to the metal coil on the low-frequency resonant structure; under the action of the external magnetic field, the low-frequency resonant structure is driven by the Lorentz force and the amplitude increases; The sensing electrode and the low-frequency resonant structure form a capacitor. The vibration of the low-frequency resonant structure causes the charge of the sensing electrode to change. The charge change of the sensing electrode is converted into a voltage signal V2 through a CV conversion circuit, and V2 is output to the external circuit as part of the composite sensitive output signal. V1 and V2 are processed and converted into DC signals, and then summed to reflect the strength of the external magnetic field.

3. The electromagnetic induction and Lorentz force composite micro magnetic sensor according to claim 1, characterized in that: The low-frequency resonance component further includes a low-frequency resonance structure side insulation layer and a metal coil, wherein the low-frequency resonance structure side insulation layer is arranged on the low-frequency resonance structure; the metal coil is arranged on the low-frequency resonance structure side insulation layer; In the working state, a DC voltage is applied to the high-frequency resonant structure and the low-frequency resonant structure; An AC voltage having the same frequency as the modal resonant frequency of the induced magnetic field of the high-frequency resonant structure is applied to the driving electrode. The high-frequency resonant structure vibrates under the action of the electrostatic force and enters a critical nonlinear state. An AC current having the same frequency and phase as the driving electrode is applied to the driving coil. Under the action of the external magnetic field, the high-frequency resonant structure enters a nonlinear state due to the Lorentz force. The electromagnetic induction coil cuts the magnetic flux lines of the external magnetic field to generate an induced electromotive force V1, which is output to the external circuit as part of the composite sensitive output signal. After the high-frequency resonant structure enters the nonlinear state, part of the energy is transferred to the low-frequency resonant structure through the coupling beam, causing the low-frequency resonant structure to start vibrating and resonant motion according to the induced magnetic field mode; The sensing electrode and the low-frequency resonant structure form a capacitor. The vibration of the low-frequency resonant structure causes the charge of the sensing electrode to change. The CV conversion circuit converts the charge change of the sensing electrode into a voltage signal V2, which is output to the external circuit as part of the composite sensitive output signal. At the same time, the metal coil on the low-frequency resonant structure cuts the magnetic flux lines of the external magnetic field to generate an induced electromotive force V3, which is output to the external circuit as part of the composite sensitive output signal. Signals V1, V2, and V3 are processed and converted into DC signals, which are then summed to reflect the strength of the external magnetic field.

4. The electromagnetic induction and Lorentz force composite micro magnetic sensor according to any one of claims 1 to 3, characterized in that: The vibration modes corresponding to the resonant modes of the high-frequency resonant structure and the low-frequency resonant structure are the same, and are both torsional resonant modes or both in-plane translational modes; If it is a torsional mode, the driving electrode and the sensing electrode should be respectively arranged between the high-frequency resonant structure and the substrate, and between the low-frequency resonant structure and the substrate; If it is an in-plane translational mode, the driving electrodes and the sensing electrodes are arranged at any position suitable for driving and detecting the structural translational mode around the high-frequency resonant structure and the low-frequency resonant structure.

5. The electromagnetic induction type and Lorentz force type composite micro magnetic sensor according to claim 2 or 3, characterized in that: The low-frequency resonance structure side insulation layer includes a low-frequency resonance structure side first insulation layer, a low-frequency resonance structure side second insulation layer and a low-frequency resonance structure side third insulation layer; The metal coil includes a first layer of metal coils, a second layer of metal coils and a third layer of metal coils; The first insulating layer on the low-frequency resonance structure side, the first metal coil, the second insulating layer on the low-frequency resonance structure side, the second metal coil, the third insulating layer on the low-frequency resonance structure side and the third metal coil are sequentially arranged on the low-frequency resonance structure.

6. The electromagnetic induction and Lorentz force composite micro magnetic sensor according to any one of claims 1 to 3, characterized in that: The high-frequency resonance component and the low-frequency resonance component each further include an anchor point and a support beam; The anchor point is provided on the substrate; One end of the support beam is fixedly connected to the anchor point, and the other end of the support beam is fixedly connected to the high-frequency resonance structure or the low-frequency resonance structure.

7. The electromagnetic induction and Lorentz force composite micro magnetic sensor according to claim 6, characterized in that: Two ends of the coupling beam are respectively connected to a support beam corresponding to the high-frequency resonance component and a support beam corresponding to the low-frequency resonance component.

8. A method for preparing a micro magnetic sensor of electromagnetic induction type and Lorentz force type composite as claimed in claim 1, characterized in that: The following steps are involved: (1) providing a substrate sheet, and depositing a metal layer on one side of the substrate by a deposition process; Defining a metal layer pattern by photolithography and etching the metal layer to form driving electrodes and sensing electrodes on the substrate; (2) providing a structural sheet, photolithographically defining a cavity pattern on the structural sheet and etching a V-shaped cavity; (3) Aligning the substrate sheet and the structure sheet and performing wafer bonding; The driving electrodes and the sensing electrodes are located in the cavity of the structural sheet; (4) Thinning the structural sheet to the required thickness through wafer thinning process; (5) depositing an insulating layer on the structural sheet, defining the insulating layer pattern by photolithography, and then etching the insulating layer to form a first insulating layer on the high-frequency resonant structure side; (6) depositing a metal layer on the surface of the structure, defining the metal layer pattern by photolithography, and then etching the metal layer to form a drive coil; the drive coil is located above the first insulating layer on the high-frequency resonant structure side; (7) depositing an insulating layer on the surface of the above structure, defining the insulating layer pattern by photolithography, and then etching the insulating layer to form a second high-frequency insulating layer on the high-frequency resonant structure side; The second high-frequency insulation layer on the high-frequency resonance structure side is located above the driving coil; (8) depositing a metal layer on the surface of the structure, defining the metal layer pattern by photolithography, and then etching the metal layer to form a metal shielding layer; the metal shielding layer is located above the second high-frequency insulating layer on the high-frequency resonant structure side; (9) depositing an insulating layer on the surface of the structure, defining the insulating layer pattern by photolithography, and then etching the insulating layer to form a third high-frequency insulating layer on the high-frequency resonant structure side; the third high-frequency insulating layer on the high-frequency resonant structure side is located above the metal shielding layer; (10) depositing a metal layer on the surface of the structure, defining the metal layer pattern by photolithography, and then etching the metal layer to form an electromagnetic induction coil; the electromagnetic induction coil is located above the third high-frequency insulating layer on the high-frequency resonant structure side; (11) The structural sheet is photolithographically defined to form an etching pattern, and the structural sheet is etched to release the movable structure, thereby forming a high-frequency resonant structure and a low-frequency resonant structure connected by a coupling beam.

9. A method for preparing a micro magnetic sensor of a composite electromagnetic induction and Lorentz force type as claimed in any one of claims 2 to 3, characterized in that: The following steps are involved: (1) providing a substrate sheet, and depositing a metal layer on one side of the substrate by a deposition process; Defining a metal layer pattern by photolithography and etching the metal layer to form driving electrodes and sensing electrodes on the substrate; (2) providing a structural sheet, photolithographically defining a cavity pattern on the structural sheet and etching a V-shaped cavity; (3) Aligning the substrate sheet and the structure sheet and performing wafer bonding; The driving electrodes and the sensing electrodes are located in the cavity of the structural sheet; (4) Thinning the structural sheet to the required thickness through wafer thinning process; (5) depositing an insulating layer on the structural sheet, defining the insulating layer pattern by photolithography, and then etching the insulating layer to form a first insulating layer on the high-frequency resonant structure side and a first insulating layer on the low-frequency resonant structure side; (6) depositing a metal layer on the surface of the structure, defining the metal layer pattern by photolithography, and then etching the metal layer to form a drive coil and a first layer of metal coil; the drive coil is located above the first insulating layer on the high-frequency resonant structure side; the first layer of metal coil is located above the first insulating layer on the low-frequency resonant structure side; (7) depositing an insulating layer on the surface of the structure, defining the insulating layer pattern by photolithography, and then etching the insulating layer to form a second high-frequency insulating layer on the high-frequency resonance structure side and a second insulating layer on the low-frequency resonance structure side; the second high-frequency insulating layer on the high-frequency resonance structure side is located above the driving coil; the second insulating layer on the low-frequency resonance structure side is located above the first metal coil; (8) depositing a metal layer on the surface of the structure, defining the metal layer pattern by photolithography, and then etching the metal layer to form a metal shielding layer and a second metal coil; the metal shielding layer is located above the second high-frequency insulating layer on the high-frequency resonant structure side; the second metal coil is located above the second insulating layer on the low-frequency resonant structure side; (9) depositing an insulating layer on the surface of the structure, defining the insulating layer pattern by photolithography, and then etching the insulating layer to form a third high-frequency insulating layer on the high-frequency resonance structure side and a third insulating layer on the low-frequency resonance structure side; the third high-frequency insulating layer on the high-frequency resonance structure side is located above the metal shielding layer; the third insulating layer on the low-frequency resonance structure side is located above the second metal coil; (10) depositing a metal layer on the surface of the structure, defining the metal layer pattern by photolithography, and then etching the metal layer to form an electromagnetic induction coil and a third metal coil; the electromagnetic induction coil is located above the third high-frequency insulating layer on the high-frequency resonant structure side; the third metal coil is located above the third insulating layer on the low-frequency resonant structure side; (11) The structural sheet is photolithographically defined to form an etching pattern, and the structural sheet is etched to release the movable structure, thereby forming a high-frequency resonant structure and a low-frequency resonant structure connected by a coupling beam.

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