MEMS gyroscope

Abstract

The invention provides an MEMS gyroscope, the MEMS gyroscope comprises a substrate, a device layer, a driving structure, a driving electrode structure, a detection structure, a detection beam and a detection electrode unit, the device layer is fixed on the substrate and comprises a plurality of structure units which are mutually connected and arranged in an array; the driving structure is located in the structure unit and comprises a mass body, a driving frame, an elastic beam, a first folding beam, a first combination beam, a second combination beam and a third combination beam. The driving electrode structure is located in the structural unit and comprises a first capacitor, a second capacitor and a third capacitor; the detection structure is located in the structural unit and comprises a detection frame and a movable electrode frame; the detection beam is located in the structural unit and connected with the movable electrode frame, and the cross endpoint is connected with the mass body; the plurality of detection electrode units are located in the internal area of the detection frame and comprise a fourth capacitor, a fifth capacitor, a sixth capacitor and a seventh capacitor which are arranged in an array. According to the MEMS gyroscope disclosed by the invention, the mechanical sensitivity is improved.

Description

Technical Field

[0001] The invention relates to the technical field of micro-electromechanical systems and micro-inertial measurement, and in particular to a MEMS gyroscope. Background Art

[0002] A microelectromechanical system (MEMS) gyroscope is an inertial sensor that measures the angular rate of rotation. It is implemented using MEMS processing technology and has the advantages of small size, low cost, light weight, and easy mass production. It is widely used.

[0003] Sensitivity is one of the important indicators of MEMS gyroscopes. In order to achieve high sensitivity of MEMS gyroscopes, under the premise of ensuring high quality factor (Q value) and low frequency cracking, the traditional linear vibration MEMS gyroscope research has designed a lever amplification structure to amplify the MEMS gyroscope drive and detect structural displacement, while the mechanical sensitivity of multi-ring resonant and disk-type 2D rotational axisymmetric MEMS gyroscopes is related to the structural angular gain, effective mass, Q value and resonant angular frequency, and the angular gain of the rotational axisymmetric MEMS gyroscope will not change with structural changes. Therefore, the main method to improve the sensitivity of planar rotational axisymmetric MEMS gyroscopes is to increase the effective inertial mass or increase the detection capacitor area. Micro-hemispherical MEMS gyroscopes generally use the outer electrode of the spherical shell for sensitive capacitance detection. Due to the large distance between the micro-hemispherical shell and the outer electrode, the method of increasing the effective inertial mass at the edge of the hemispherical shell is usually used to improve the mechanical sensitivity.

[0004] The current methods to increase the mechanical sensitivity of MEMS gyroscopes are generally to increase the movable inertial mass or detect capacitance, but both have certain limitations in increasing sensitivity. Since the spacing between the capacitor comb teeth is in the micrometer range and the displacement change is in the nanometer range, the signal change is very weak.

[0005] In view of this, there is an urgent need for a MEMS gyroscope that can enhance the detection signal and thus improve the mechanical sensitivity. Summary of the invention

[0006] In view of the above-mentioned shortcomings of the prior art, an object of the present invention is to provide a MEMS gyroscope for solving the problems of weak detection signal and low mechanical sensitivity of the MEMS gyroscope in the prior art.

[0007] To achieve the above object and other related objects, the present invention provides a MEMS gyroscope, comprising:

[0008] substrate;

[0009] A device layer, fixed on the substrate, wherein the device layer includes a plurality of structural units that are interconnected and arranged in an array;

[0010] A driving structure, located in the structural unit and comprising a mass body, a driving frame, an elastic beam, a first folding beam, a first combined beam, a second combined beam and a third combined beam, wherein a plurality of elastic beams are provided on both sides of the mass body along the Y-axis direction, the mass body is connected to the driving frame through the elastic beams, the first combined beam is located on a side of the mass body away from the X-axis direction and is connected to the driving frame, and the first combined beam is connected to a balance bar through the first folding beam, the second combined beam is located on a side of the mass body along the X-axis direction, the third combined beam is located in the mass body, and the X-axis and the Y-axis are perpendicular to each other;

[0011] a driving electrode structure, located in the structural unit and comprising a first capacitor and a second capacitor located on both sides of the first folded beam along the Y-axis direction and respectively connected to the driving frame, and a third capacitor located on one side of the second combined beam along the X-axis direction;

[0012] A detection structure, located in the structural unit and comprising a detection frame connected to the balance bar and a movable electrode frame connected to the detection frame via a second folding beam;

[0013] A detection beam, located in the structural unit and connected to one side of the movable electrode frame along the X-axis direction, wherein the cross end point of the detection beam is connected to the mass body through a single beam and a third combined beam;

[0014] A plurality of detection electrode units are located in the inner area of ​​the detection frame and connected to the movable electrode frame. The detection electrode units include a fourth capacitor, a fifth capacitor, a sixth capacitor and a seventh capacitor arranged in an array.

[0015] Optionally, the device layer includes four structural units that are interconnected and arranged in a rectangular shape, two of the structural units arranged along the X-axis direction are symmetrically distributed about the center line of the substrate along the Y-axis direction, and two of the structural units arranged along the Y-axis direction are symmetrically distributed about the center line of the substrate along the X-axis direction.

[0016] Optionally, two adjacent structural units arranged along the X-axis direction are connected via a common third folding beam; and two adjacent structural units arranged along the Y-axis direction are connected via a common balance bar.

[0017] Optionally, the detection beams in two of the structural units arranged along the Y-axis direction are connected via a fourth folding beam connected to the detection beams.

[0018] Optionally, the shape of the detection beam includes a V shape.

[0019] Optionally, the angle between the first beam arm and the second beam arm of the detection beam ranges from 20 degrees to 40 degrees.

[0020] Optionally, the first beam arm is composed of a plurality of single straight beams; and the second beam arm is composed of a plurality of single straight beams.

[0021] Optionally, the first capacitor is composed of a first movable electrode and a first fixed electrode connected to each other; the second capacitor is composed of a second movable electrode and a second fixed electrode connected to each other; and the third capacitor is composed of a third movable electrode and a third fixed electrode connected to each other.

[0022] Optionally, the fourth capacitor is composed of a fourth fixed electrode and a fourth movable electrode surrounding the fourth fixed electrode; the fifth capacitor is composed of a fifth fixed electrode and a fifth movable electrode surrounding the fifth fixed electrode; the sixth capacitor is composed of a sixth fixed electrode and a sixth movable electrode surrounding the sixth fixed electrode; and the seventh capacitor is composed of a seventh fixed electrode and a frequency tuning electrode surrounding the seventh fixed electrode.

[0023] Optionally, the first composite beam is connected to the mass body via a first fixed anchor point; and the second composite beam is connected to the mass body via a second fixed anchor point.

[0024] Optionally, the balance bar is provided with a connected T-beam and a third fixed anchor point, and the third fixed anchor point is fixed to the balance bar through the T-beam.

[0025] As described above, the MEMS gyroscope of the present invention has the following beneficial effects: by arranging the detection beam in the MEMS gyroscope, the displacement in the detection direction of the MEMS gyroscope is effectively increased, and by changing the angle between the first beam arm and the second beam arm, a displacement magnification factor of 373% or more is achieved, thereby improving the mechanical sensitivity of the MEMS gyroscope; by arranging four interconnected and rectangularly arranged structural units in the device layer of the MEMS gyroscope, and two of the structural units arranged along the X-axis direction are symmetrically distributed about the center line of the substrate along the Y-axis direction, and two of the structural units arranged along the Y-axis direction are symmetrically distributed about the center line of the substrate along the X-axis direction, a four-mass double tuning fork differential detection system is formed, and when the MEMS is in the detection mode At the same time, the design of four-mass fully differential symmetrical output can eliminate the influence of acceleration along the detection direction, and can effectively eliminate the acceleration interference introduced from the outside, thereby improving the environmental adaptability of the MEMS gyroscope and improving the anti-vibration effect of the MEMS gyroscope; by setting the first combined beam, the second combined beam, the third combined beam, the first folding beam, the second folding beam, the third folding beam, the detection beam and the elastic beam connecting the mass block, the driving frame and the detection frame as decoupling beams, full decoupling of the driving direction and the detection direction is achieved, and the coupling error signal caused by the Coriolis force motion coupling is eliminated. The decoupling beam is used to couple the four inertia-sensitive mass bodies, thereby avoiding the situation where the intrinsic frequency of the MEMS gyroscope does not match due to processing errors. BRIEF DESCRIPTION OF THE DRAWINGS

[0026] Figure 1 Shown is a schematic structural diagram of the MEMS gyroscope of the present invention.

[0027] Figure 2 Shown is a schematic structural diagram of a structural unit of a MEMS gyroscope of the present invention.

[0028] Figure 3 Shown is a partial structural schematic diagram of the MEMS gyroscope of the present invention.

[0029] Figure 4 It is a schematic structural diagram of a first composite beam of the MEMS gyroscope of the present invention.

[0030] Figure 5 Shown is another partial structural schematic diagram of the MEMS gyroscope of the present invention.

[0031] Figure 6 Shown is a third partial structural schematic diagram of the MEMS gyroscope of the present invention.

[0032] Figure 7It is a schematic diagram showing the driving modes of the structural unit of the MEMS gyroscope of the present invention.

[0033] Figure 8 A partial schematic diagram showing the driving mode of the structural unit of the MEMS gyroscope of the present invention is shown.

[0034] Fig. 9 Another partial schematic diagram showing the driving mode of the structural unit of the MEMS gyroscope of the present invention.

[0035] Fig.10 Shown is a schematic diagram of the detection mode of the structural unit of the MEMS gyroscope of the present invention.

[0036] Fig.11 A partial schematic diagram showing the detection mode of the structural unit of the MEMS gyroscope of the present invention is shown.

[0037] Fig.12 Another partial schematic diagram showing the detection mode of the structural unit of the MEMS gyroscope of the present invention is shown.

[0038] Fig.13 A third partial schematic diagram showing the detection mode of the structural unit of the MEMS gyroscope of the present invention is shown.

[0039] Fig.14 A fourth partial schematic diagram showing the detection mode of the structural unit of the MEMS gyroscope of the present invention.

[0040] Component number description

[0041] 1 Device layer

[0042] 11 Structural unit

[0043] 2. Drive structure

[0044] 21 Mass

[0045] 22 Driver Framework

[0046] 23 Elastic beam

[0047] 24 First folding beam

[0048] 25 First composite beam

[0049] 26 Second composite beam

[0050] 27 The third composite beam

[0051] 3 Driving electrode structure

[0052] 31 First Capacitor

[0053] 311 First movable electrode

[0054] 312 first fixed electrode

[0055] 32 Second capacitor

[0056] 321 Second movable electrode

[0057] 322 second fixed electrode

[0058] 33 Third capacitor

[0059] 331 Third movable electrode

[0060] 332 third fixed electrode

[0061] 4 Detection structure

[0062] 41 Detection Framework

[0063] 42 Movable electrode frame

[0064] 43 Second folding beam

[0065] 5. Detection beam

[0066] 51 First beam arm

[0067] 52 Second beam arm

[0068] 6 Detection electrode unit

[0069] 61 Fourth Capacitor

[0070] 611 Fourth fixed electrode

[0071] 612 fourth movable electrode

[0072] 62 Fifth Capacitor

[0073] 621 Fifth fixed electrode

[0074] 622 Fifth movable electrode

[0075] 63 Sixth Capacitor

[0076] 631 Sixth fixed electrode

[0077] 632 Sixth movable electrode

[0078] 64 Seventh Capacitor

[0079] 641 Seventh Fixed Electrode

[0080] 642 Seventh Frequency Tuning Electrode

[0081] 7. Balance bar

[0082] 71 T-beam

[0083] 8 Single beam

[0084] 9 Third folding beam

[0085] 10 Fourth folding beam

[0086] 1a First fixed anchor point

[0087] 2a Second fixed anchor point

[0088] 3a Third fixed anchor point

[0089] 4a Fourth fixed anchor point

[0090] 5a Fifth fixed anchor point

[0091] 6a Sixth fixed anchor point

[0092] 7a Seventh fixed anchor point DETAILED DESCRIPTION

[0093] The following is a description of the implementation of the present invention by means of specific embodiments. Those skilled in the art can easily understand other advantages and effects of the present invention from the contents disclosed in this specification.

[0094] See also Figures 1 to 14 . It should be noted that the structures, proportions, sizes, etc. illustrated in the drawings in this specification are only used to match the contents disclosed in the specification for people familiar with this technology to understand and read, and are not used to limit the limiting conditions for the implementation of the present invention, so they have no substantial technical significance. Any modification of the structure, change in the proportional relationship, or adjustment of the size should still fall within the scope of the technical content disclosed by the present invention without affecting the effects and purposes that can be achieved by the present invention. At the same time, the terms such as "upper", "lower", "left", "right", "middle" and "one" quoted in this specification are only for the convenience of description, and are not used to limit the scope of the implementation of the present invention. Changes or adjustments in their relative relationships should also be regarded as the scope of the implementation of the present invention without substantially changing the technical content.

[0095] Embodiment 1

[0096] This embodiment provides a MEMS gyroscope, such as Figure 1 to Figure 2As shown, it is a structural schematic diagram of the MEMS gyroscope and a structural schematic diagram of the structural unit 11, the MEMS gyroscope includes: a substrate (not shown), a device layer 1, a driving structure 2, a driving electrode structure 3, a detection structure 4, a detection beam 5 and a plurality of detection electrode units 6, wherein the device layer 1 is fixed on the substrate, and the device layer 1 includes a plurality of structural units 11 that are interconnected and arranged in an array; the driving structure 2 is located in the structural unit 11 and includes a mass body 21, a driving frame 22, an elastic beam 23, a first folding beam 24, a first combined beam 25, a second combined beam 26 and a third combined beam 27, the mass body 21 is provided with a plurality of elastic beams 23 on both sides along the Y-axis direction, the mass body 21 is connected to the driving frame 22 through the elastic beams 23, the first combined beam 25 is located on the side of the mass body away from the X-axis direction and is connected to the driving frame 22, and the first combined beam 25 is connected to the balance bar 7 through the first folding beam 24, and the second combined beam 26 is located on the mass body 21 along the X-axis direction. on one side, the mass body 21 surrounds the third combined beam 27, and the X-axis and the Y-axis are perpendicular to each other; the driving electrode structure 3 is located in the structural unit 11 and includes a first capacitor 31 and a second capacitor 32 located on both sides of the first folding beam 24 along the Y-axis direction and connected to the driving frame respectively, and a third capacitor 33 located on one side of the second combined beam 26 along the X-axis direction; the detection structure 4 is located in the structural unit 11 and includes a detection frame 41 connected to the balance bar 7 and a movable electrode frame 42 connected to the detection frame 41 through a second folding beam 43; the detection beam 5 is located in the structural unit 11 and is connected to one side of the movable electrode frame 42 along the X-axis direction, and the cross end point of the detection beam 5 is connected to the mass body 21 through a single beam 8 and a third combined beam 27; a plurality of the detection electrode units 6 are located in the internal area of ​​the detection frame 41 and are connected to the movable electrode frame 42, and the detection electrode unit 6 includes a fourth capacitor 61, a fifth capacitor 62, a sixth capacitor 63 and a seventh capacitor 64 arranged in an array.

[0097] Specifically, the material of the substrate includes silicon or other suitable materials.

[0098] Specifically, under the condition that the performance of the MEMS gyroscope is met, the shape and size of the substrate can be selected according to actual conditions and are not limited here.

[0099] As an example, the device layer 1 includes four structural units 11 that are interconnected and arranged in a rectangular shape, two of the structural units 11 arranged along the X-axis direction are symmetrically distributed about the center line of the substrate along the Y-axis direction, and two of the structural units 11 arranged along the Y-axis direction are symmetrically distributed about the center line of the substrate along the X-axis direction.

[0100] As an example, two adjacent structural units 11 arranged along the X-axis direction are connected via a common third folding beam 9 ; and two adjacent structural units 11 arranged along the Y-axis direction are connected via a common balance bar 7 .

[0101] Specifically, the third folding beam 9 is formed by four single straight beams connected in a U shape.

[0102] Specifically, under the condition that the performance of the MEMS gyroscope is met, the size and material of the third folding beam 9 can be selected according to actual conditions and are not limited here.

[0103] Specifically, the common balance rod 7 in the two structural units 11 arranged along the Y-axis direction is fixed by the fourth fixed anchor point 4a and the fifth fixed anchor point 5a, so that the MEMS gyroscope maintains balance and stability during operation.

[0104] Specifically, while meeting the performance of the MEMS gyroscope, the shape, size and material of the fourth fixed anchor point 4a can be selected according to actual conditions and are not limited here; the shape, size and material of the fifth fixed anchor point 5a can be selected according to actual conditions and are not limited here.

[0105] Specifically, under the condition that the performance of the MEMS gyroscope is met, the shape, size and material of the driving frame 22 can be selected according to actual conditions and are not limited here.

[0106] Specifically, under the condition that the performance of the MEMS gyroscope is met, the shape, size and material of the mass body 21 can be selected according to actual conditions and are not limited here.

[0107] Specifically, under the condition that the performance of the MEMS gyroscope is met, the number, shape, size and material of the elastic beams 23 can be selected according to actual conditions, and are not limited here. In this embodiment, a total of four elastic beams 23 are provided on both sides of the mass body 21 along the Y-axis direction, wherein two elastic beams 23 are provided on one side of the mass body 23 along the Y-axis direction, and two elastic beams 23 are provided on the side of the mass body 21 away from the Y-axis direction.

[0108] As an example, Figure 3 , which is a schematic diagram of a first partial structure of the MEMS gyroscope, the first combined beam 25 is connected to the mass body 21 through a first fixed anchor point 1a; the second combined beam 26 is connected to the mass body 21 through a second fixed anchor point 2a.

[0109] Specifically, while meeting the performance of the MEMS gyroscope, the shape, size and material of the first fixed anchor point 1a can be selected according to actual conditions and are not limited here; the shape, size and material of the second fixed anchor point 2a can be selected according to actual conditions and are not limited here.

[0110] Specifically, under the condition that the performance of the MEMS gyroscope is met, the shape, size and material of the first combined beam 25 can be selected according to actual conditions and are not limited here.

[0111] Specifically, Figure 4 , which is a schematic structural diagram of the first combined beam 25 , wherein the first combined beam 25 comprises a first portion 251 and a second portion 252 connected to a base 253 , wherein the first portion 251 and the second portion 252 are fixed to the first base 253 .

[0112] Specifically, the first part 251 is formed by connecting and combining six single straight beams; the second part 252 is formed by connecting and combining six single straight beams.

[0113] Specifically, under the condition that the performance of the MEMS gyroscope is met, the shape, size and material of the second combined beam 26 can be selected according to actual conditions and are not limited here.

[0114] Specifically, the second combined beam 26 includes a third portion 261 and a fourth portion 262 connected to a second base 263 , and the third portion 261 and the fourth portion 262 are fixed on the second base 263 .

[0115] Specifically, the third portion 261 is formed by connecting and combining six single straight beams; and the fourth portion 262 is formed by connecting and combining six single straight beams.

[0116] As an example, the balance pole 7 is provided with a T-beam 71 and third and fourth fixing anchor points 3 a connected to each other, and the third fixing anchor point 3 a is fixed to the balance pole 7 through the T-beam 71 .

[0117] Specifically, while meeting the performance of the MEMS gyroscope, the shape, size and material of the balance bar 7 can be selected according to actual conditions, and are not limited here; the shape, size and material of the T-beam 71 can be selected according to actual conditions, and are not limited here; the shape, size and material of the third fixed anchor point 3a can be selected according to actual conditions, and are not limited here.

[0118] Specifically, the third composite beam 27 is formed by connecting two outer longer single straight beams and two inner shorter single straight beams.

[0119] Specifically, under the condition that the performance of the MEMS gyroscope is met, the shape, size and material of the third combined beam 27 can be selected according to actual conditions and are not limited here.

[0120] Specifically, under the condition that the performance of the MEMS gyroscope is met, the shape, size and material of the first folding beam 24 can be selected according to actual conditions and are not limited here.

[0121] As an example, the first capacitor 31 is composed of a first movable electrode 311 and a first fixed electrode 312 connected to each other; the second capacitor 32 is composed of a second movable electrode 321 and a second fixed electrode 322 connected to each other; and the third capacitor 33 is composed of a third movable electrode 331 and a third fixed electrode 332 connected to each other.

[0122] Specifically, while meeting the performance of the MEMS gyroscope, the shape, size and material of the first movable electrode 311 can be selected according to actual conditions, without any limitation here; the shape, size and material of the second movable electrode 321 can be selected according to actual conditions, without any limitation here; the shape, size and material of the third movable electrode 331 can be selected according to actual conditions, without any limitation here.

[0123] Specifically, while meeting the performance of the MEMS gyroscope, the shape, size and material of the first fixed electrode 312 can be selected according to actual conditions, without limitation here; the shape, size and material of the second fixed electrode 322 can be selected according to actual conditions, without limitation here; the shape, size and material of the third fixed electrode 332 can be selected according to actual conditions, without limitation here.

[0124] Specifically, under the condition that the performance of the MEMS gyroscope is met, the size and material of the detection frame 41 can be selected according to actual conditions and are not limited here.

[0125] Specifically, under the condition that the performance of the MEMS gyroscope is met, the size and material of the movable electrode frame 42 can be selected according to actual conditions, and are not limited here.

[0126] Specifically, the second folding beam 43 is composed of two single beams.

[0127] Specifically, the shape of the second folding beam 43 includes a U-shape or other suitable shapes.

[0128] Specifically, under the condition that the performance of the MEMS gyroscope is met, the material of the second folding beam 43 can be selected according to actual conditions and is not limited here.

[0129] As an example, the shape of the detection beam 5 includes a V-shape or other suitable shapes.

[0130] As an example, the angle between the first beam arm 51 and the second beam arm 52 of the detection beam 5 ranges from 20 degrees to 40 degrees. In this embodiment, the angle between the first beam arm 51 and the second beam arm 52 of the detection beam is 30 degrees.

[0131] Specifically, the vertices of one end of the first beam arm 51 and the second beam arm 52 of the detection beam 5 cross each other to form a V-shaped detection beam, that is, the detection beam 5 is designed to be cross-movable.

[0132] As an example, the first beam arm 51 is composed of a plurality of single straight beams; the second beam arm 52 is composed of a plurality of single straight beams. In this embodiment, the first beam arm 51 is composed of three single straight beams, including three single straight beams with widths of 8μm, 15μm, and 8μm, and lengths of 160μm, 225μm, and 160μm, respectively; the second beam arm 52 is composed of three single straight beams, including three single straight beams with widths of 8μm, 15μm, and 8μm, and lengths of 160μm, 225μm, and 160μm, respectively.

[0133] Specifically, three single straight beams are used to form the first beam arm 51 , and three single straight beams are used to form the second beam arm 52 , so as to facilitate the adjustment of the stiffness of the first beam arm 51 and the second beam arm 52 of the detection beam 5 .

[0134] Specifically, under the condition that the performance of the MEMS gyroscope is met, the material of the single straight beam can be selected according to actual conditions, and is not limited here.

[0135] Specifically, by setting the detection beam, the displacement in the detection direction of the MEMS gyroscope is effectively increased, and by changing the angle between the first beam arm 51 and the second beam arm 52, a displacement amplification factor of 373% or more can be achieved, thereby improving the mechanical sensitivity of the MEMS gyroscope.

[0136] As an example, the detection beams 5 in the two structural units 11 arranged along the Y-axis direction are connected by a fourth folding beam 10 connected to the detection beams 5 .

[0137] Specifically, the fourth folding beam 10 connects the movable electrode frames 42 located on both sides of the detection beam 5 along the X-axis direction.

[0138] Specifically, the fourth folding beam 10 is formed by two single straight beams connected in a U shape.

[0139] Specifically, the inner area of ​​the detection frame 41 includes two detection electrode units 6 , and the two detection electrode units 6 are respectively located on both sides of the detection beam 5 and are symmetrically distributed about the center line of the detection beam 5 along the Y-axis direction.

[0140] Specifically, the fourth capacitor 61, the fifth capacitor 62, the sixth capacitor 63 and the seventh capacitor 64 in the detection electrode unit 6 are arranged and distributed in a matrix, that is, in this embodiment, the four capacitors in the detection electrode unit 6 are distributed in 2 rows and 2 columns.

[0141] As an example, Figures 5 and 6 As shown, they are another partial structural schematic diagram of the MEMS gyroscope and a third partial structural schematic diagram of the MEMS gyroscope, respectively, the fourth capacitor 61 is composed of a fourth fixed electrode 611 and a fourth movable electrode 612 surrounding the fourth fixed electrode 611; the fifth capacitor 62 is composed of a fifth fixed electrode 621 and a fifth movable electrode 622 surrounding the fifth fixed electrode 621; the sixth capacitor 63 is composed of a sixth fixed electrode 631 and a sixth movable electrode 632 surrounding the sixth fixed electrode 631; the seventh capacitor 64 is composed of a seventh fixed electrode 641 and a frequency tuning electrode 642 surrounding the seventh fixed electrode 641.

[0142] Specifically, while satisfying the performance of the MEMS gyroscope, the shape, size and material of the fourth movable electrode 612 can be selected according to actual conditions, without limitation here; the shape, size and material of the fifth movable electrode 622 can be selected according to actual conditions, without limitation here; the shape, size and material of the sixth movable electrode 632 can be selected according to actual conditions, without limitation here; the shape, size and material of the frequency coordination electrode 642 can be selected according to actual conditions, without limitation here.

[0143] Specifically, while meeting the performance of the MEMS gyroscope, the shape, size and material of the fourth fixed electrode 611 can be selected according to actual conditions, without any restriction; the shape, size and material of the fifth fixed electrode 621 can be selected according to actual conditions, without any restriction; the shape, size and material of the sixth fixed electrode 631 can be selected according to actual conditions, without any restriction; the shape, size and material of the seventh fixed electrode 641 can be selected according to actual conditions, without any restriction.

[0144] Specifically, the MEMS gyroscope is further provided with the sixth fixed anchor point 6 a and the seventh fixed anchor point 7 a , and the sixth fixed anchor point 6 a and the seventh fixed anchor point 7 a are located between the four structural units 11 .

[0145] Specifically, Figures 7 to 9 As shown, they are respectively a schematic diagram of the driving mode of the structural unit of the MEMS gyroscope, a partial schematic diagram of the driving mode of the structural unit of the MEMS gyroscope, and another partial schematic diagram of the driving mode of the structural unit of the MEMS gyroscope. When the MEMS gyroscope is driven to work, the first capacitors 31 in the two structural units 11 arranged along the X-axis direction and located in the upper half of the Y-axis are respectively applied with in-phase AC voltages, and then a DC bias voltage is respectively applied to the two mass blocks 21, so that a driving electrostatic force can be generated, and the first combined beams 25, the second combined beams 26, the third combined beams 27 and the third folding beam 9 in the two structural units 11 perform opening and closing movements in the driving frame 22, and the movement states of the beams in the two structural units 11 are opposite, and then The two mass blocks 21 in the two structural units 11 located in the upper half of the Y-axis are made to oscillate in opposite directions; the first capacitors 31 in the two structural units 11 located in the lower half of the Y-axis and arranged along the X-axis direction are respectively applied with the same-phase AC voltage, and then a DC bias voltage is applied to the two mass blocks 21, so as to generate a driving electrostatic force, and the movement state of the first combined beam 25, the second combined beam 26, the third combined beam 27 and the third folding beam 9 in the two structural units 11 located in the lower half of the Y-axis in the driving frame 22 is opposite to that in the two structural units 11 located in the upper half of the Y-axis, thereby making the two mass blocks 21 in the two structural units 11 located in the lower half of the Y-axis oscillate in opposite directions.

[0146] Specifically, when the MEMS gyroscope vibrates, the third capacitor 33 in the MEMS gyroscope symmetrically distributed about the X-axis changes in opposite directions, and the differential analysis of the driving mode of the MEMS gyroscope can be achieved by subtracting the capacitance values ​​of the two third capacitors 33 in the two structural units 11 symmetrically distributed about the X-axis. In this embodiment, the driving mode resonant frequency of the MEMS gyroscope is 13863 Hz.

[0147] Specifically, Figure 10-14As shown, they are respectively a schematic diagram of the detection mode of the structural unit of the MEMS gyroscope, a partial schematic diagram of the detection mode of the structural unit of the MEMS gyroscope, another partial schematic diagram of the detection mode of the structural unit of the MEMS gyroscope, a third partial schematic diagram of the detection mode of the structural unit of the MEMS gyroscope, and a fourth partial schematic diagram of the detection mode of the structural unit of the MEMS gyroscope. When the MEMS gyroscope is in the driving mode, an angular velocity along the Z-axis direction is applied by the outside world. At this time, the two mass blocks 21 in the two structural units 11 arranged along the X-axis direction and located in the upper half of the Y-axis will be subjected to Coriolis forces in opposite directions along the Y-axis direction, and the directions of the Coriolis forces on the mass blocks 21 in the two structural units 11 located in the lower half of the Y-axis are opposite to the directions of the Coriolis forces on the mass blocks 21 in the corresponding two structural units 11 located in the upper half of the Y-axis. The Coriolis force exerted on the mass block 21 is transmitted to the detection frame 41 through the detection beam 5, so that the movable electrode frame 42 inside the detection frame 41 produces opposite oscillating motion; when the MEMS gyroscope is in detection mode motion, the fourth capacitors 61 in the two structural units 11 located on the same side of the center line of the detection beam 5 along the Y-axis direction change in the same direction, and the two fourth capacitors 61 in the structural unit 11 symmetrical about the center line of the detection beam 5 along the Y-axis direction will form a differential detection output, which suppresses the error caused by the acceleration of the detection direction. Applying a reverse voltage to the fifth capacitor 62 and the sixth capacitor 63 can generate an electrostatic force, and the electrostatic force is opposite to the Coriolis force, which can suppress the motion of the detection mode of the MEMS gyroscope, thereby realizing the closed-loop control of the MEMS gyroscope. In this embodiment, the detection mode resonant frequency of the MEMS gyroscope is 13919Hz.

[0148] Specifically, by providing four interconnected and rectangularly arranged structural units 11 in the device layer of the MEMS gyroscope, and two of the structural units 11 arranged along the X-axis direction are symmetrically distributed about the center line of the substrate along the Y-axis direction, and two of the structural units 11 arranged along the Y-axis direction are symmetrically distributed about the center line of the substrate along the X-axis direction, a four-mass double tuning fork differential detection system is formed. When the MEMS is in the detection mode, the design of the four-mass fully differential symmetrical output can eliminate the influence of acceleration along the detection direction, and can effectively eliminate the acceleration interference introduced from the outside, thereby improving the environmental adaptability of the MEMS gyroscope and improving the anti-vibration effect of the MEMS gyroscope.

[0149] Specifically, Figure 10-12As shown, when the upper and lower ends of the detection beam 5 are subjected to the force in the Y-axis direction, the detection beam 5 will generate displacement in the Y-axis direction. Due to the V-shaped and movable design of the detection beam 5, the other end of the detection beam 5 will generate displacement in the X-axis direction, and it is greater than the displacement in the Y-axis direction. If the displacement in the Y-axis direction is set to v, and the displacement in the X-axis direction is set to u, it can be obtained that u = αv, α = 1 / tanθ, where θ is half of the angle between the first beam arm 51 and the second beam arm 52 in the detection beam 5, and α is the magnification of the mechanical sensitivity. In this embodiment, the angle is 30 degrees, and the magnification α = 3.73. The magnification of the mechanical sensitivity can be changed by adjusting the angle between the first beam arm 51 and the second beam arm 52.

[0150] Specifically, the first combined beam 25, the second combined beam 26, the third combined beam 27, the first folding beam 24, the second folding beam 43, the third folding beam 9, the elastic beam 23, and the detection beam 5 used to connect the mass block 21, the driving frame 22, and the detection frame 41 are all decoupling beams. The decoupling beams are used for connection to achieve full decoupling of the driving direction and the detection direction, eliminate the coupling error signal caused by the Coriolis force motion coupling, and use the decoupling beams to couple the four inertia-sensitive mass bodies 21 to avoid the situation where the intrinsic frequency of the MEMS gyroscope does not match due to processing errors.

[0151] The MEMS gyroscope of this embodiment effectively increases the displacement in the detection direction of the MEMS gyroscope by setting the detection beam 5, and achieves a displacement magnification of 373% or more by changing the angle between the first beam arm 51 and the second beam arm 52, thereby improving the mechanical sensitivity of the MEMS gyroscope; by setting four interconnected and rectangularly arranged structural units 11 in the device layer 1 of the MEMS gyroscope, and two of the structural units 11 arranged along the X-axis direction are symmetrically distributed about the center line of the substrate along the Y-axis direction, and two of the structural units 11 arranged along the Y-axis direction are symmetrically distributed about the center line of the substrate along the X-axis direction, a four-mass double tuning fork differential detection system is formed, and when the MEMS is in the detection mode, the design of the four-mass fully differential symmetrical output can be In order to eliminate the influence of acceleration along the detection direction, the acceleration interference introduced from the outside can be effectively eliminated, the environmental adaptability of the MEMS gyroscope is improved, and the anti-vibration effect of the MEMS gyroscope is improved; by setting the first combined beam 25, the second combined beam 26, the third combined beam 27, the first folding beam 24, the second folding beam 43, the third folding beam 9, the detection beam 5 and the elastic beam 23 connecting the mass block 21, the driving frame 22, and the detection frame 41 as decoupling beams, full decoupling of the driving direction and the detection direction is achieved, the coupling error signal caused by the Coriolis force motion coupling is eliminated, and the four inertia-sensitive mass bodies 21 are coupled by using decoupling beams, avoiding the situation where the intrinsic frequency of the MEMS gyroscope does not match due to processing errors.

[0152] In summary, the present invention effectively increases the displacement in the detection direction of the MEMS gyroscope by arranging the detection beam in the MEMS gyroscope, and realizes a displacement magnification of 373% or more by changing the angle between the first beam arm and the second beam arm, thereby improving the mechanical sensitivity of the MEMS gyroscope; by arranging four interconnected and rectangularly arranged structural units in the device layer of the MEMS gyroscope, and the two structural units arranged along the X-axis direction are symmetrically distributed about the center line of the substrate along the Y-axis direction, and the two structural units arranged along the Y-axis direction are symmetrically distributed about the center line of the substrate along the X-axis direction, a four-mass double tuning fork differential detection system is formed, and when the MEMS is in the detection mode, the four masses are fully The design of differential symmetrical output can eliminate the influence of acceleration along the detection direction, effectively eliminate the acceleration interference introduced from the outside, improve the environmental adaptability of the MEMS gyroscope, and improve the anti-vibration effect of the MEMS gyroscope; by setting the first composite beam, the second composite beam, the third composite beam, the first folding beam, the second folding beam, the third folding beam, the detection beam and the elastic beam that connect the mass block, the driving frame and the detection frame as decoupling beams, the full decoupling of the driving direction and the detection direction is achieved, the coupling error signal caused by the Coriolis force motion coupling is eliminated, and the decoupling beam is used to couple the four inertia-sensitive mass bodies, avoiding the situation where the intrinsic frequency of the MEMS gyroscope does not match due to processing errors. Therefore, the present invention effectively overcomes various shortcomings in the prior art and has a high industrial utilization value.

[0153] The above embodiments are merely illustrative of the principles and effects of the present invention, and are not intended to limit the present invention. Anyone familiar with the art may modify or alter the above embodiments without departing from the spirit and scope of the present invention. Therefore, all equivalent modifications or alterations made by a person of ordinary skill in the art without departing from the spirit and technical concept disclosed by the present invention shall still be covered by the claims of the present invention.

Claims

1. A MEMS gyroscope, characterized in that: include: substrate; A device layer, fixed on the substrate, wherein the device layer includes a plurality of structural units that are interconnected and arranged in an array; A driving structure, located in the structural unit and comprising a mass body, a driving frame, an elastic beam, a first folding beam, a first combined beam, a second combined beam and a third combined beam, wherein a plurality of elastic beams are provided on both sides of the mass body along the Y-axis direction, the mass body is connected to the driving frame through the elastic beams, the first combined beam is located on a side of the mass body away from the X-axis direction and is connected to the driving frame, and the first combined beam is connected to a balancing rod through the first folding beam, the second combined beam is located on one side of the mass body along the X-axis direction, the mass body surrounds the third combined beam, and the X-axis and the Y-axis are perpendicular to each other; a driving electrode structure, located in the structural unit and comprising a first capacitor and a second capacitor located on both sides of the first folded beam along the Y-axis direction and respectively connected to the driving frame, and a third capacitor located on one side of the second combined beam along the X-axis direction; A detection structure, located in the structural unit and comprising a detection frame connected to the balance bar and a movable electrode frame connected to the detection frame via a second folding beam; A detection beam, located in the structural unit and connected to one side of the movable electrode frame along the X-axis direction, wherein the cross end point of the detection beam is connected to the mass body through a single beam and a third combined beam; A plurality of detection electrode units are located in the inner area of ​​the detection frame and connected to the movable electrode frame. The detection electrode units include a fourth capacitor, a fifth capacitor, a sixth capacitor and a seventh capacitor arranged in an array.

2. The MEMS gyroscope according to claim 1, characterized in that: The device layer includes four structural units that are interconnected and arranged in a rectangular shape, two of the structural units arranged along the X-axis direction are symmetrically distributed about the center line of the substrate along the Y-axis direction, and two of the structural units arranged along the Y-axis direction are symmetrically distributed about the center line of the substrate along the X-axis direction.

3. The MEMS gyroscope according to claim 2, characterized in that: Two adjacent structural units arranged along the X-axis direction are connected via a common third folding beam; and two adjacent structural units arranged along the Y-axis direction are connected via a common balance bar.

4. The MEMS gyroscope according to claim 2, characterized in that: The detection beams in the two structural units arranged along the Y-axis direction are connected via a fourth folding beam connected to the detection beams.

5. The MEMS gyroscope according to claim 1, characterized in that: The shape of the detection beam includes a V shape.

6. The MEMS gyroscope according to claim 5, characterized in that: The angle between the first beam arm and the second beam arm of the detection beam ranges from 20 degrees to 40 degrees.

7. The MEMS gyroscope according to claim 6, characterized in that: The first beam arm is composed of a plurality of single straight beams; and the second beam arm is composed of a plurality of single straight beams.

8. The MEMS gyroscope according to claim 1, characterized in that: The first capacitor is composed of a first movable electrode and a first fixed electrode connected to each other; the second capacitor is composed of a second movable electrode and a second fixed electrode connected to each other; The third capacitor is composed of a third movable electrode and a third fixed electrode connected to each other.

9. The MEMS gyroscope according to claim 1, characterized in that: The fourth capacitor is composed of a fourth fixed electrode and a fourth movable electrode surrounding the fourth fixed electrode; the fifth capacitor is composed of a fifth fixed electrode and a fifth movable electrode surrounding the fifth fixed electrode; the sixth capacitor is composed of a sixth fixed electrode and a sixth movable electrode surrounding the sixth fixed electrode; the seventh capacitor is composed of a seventh fixed electrode and a frequency tuning electrode surrounding the seventh fixed electrode.

10. The MEMS gyroscope according to claim 1, characterized in that: The first composite beam is connected to the mass body via a first fixed anchor point; the second composite beam is connected to the mass body via a second fixed anchor point.

11. The MEMS gyroscope according to claim 1, characterized in that: The balance bar is provided with a connected T-shaped beam and a third fixed anchor point, and the third fixed anchor point is fixed to the balance bar through the T-shaped beam.

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