CN212410634U - Triaxial resonance capacitance type micro-electromechanical accelerometer - Google Patents

Abstract

The utility model discloses a triaxial resonance capacitance type micro-electromechanical accelerometer, which comprises an upper cover plate layer, a plane structure layer and a lower basal layer which are sequentially stacked from top to bottom; the plane structure layer comprises four groups of resonance type micro accelerometers, and the four groups of resonance type micro accelerometers are arranged in a centrosymmetric mode and jointly complete the detection of acceleration in the horizontal direction; electrode leads are buried in the upper cover plate layer and the lower basal layer and serve as fixed substrates, and the upper cover plate layer and the lower basal layer and the sensitive mass block in the planar structural layer jointly form a differential capacitive micro-accelerometer for detecting the acceleration in the vertical direction. The utility model discloses an adopt in the face resonant mode to detect X axle, Y axle, the off-plate capacitance type detects the Z axle, and the triaxial all adopts the mode that the difference detected for triaxial complete decoupling zero mutually noninterference has characteristics such as high accuracy, high stability, small, environment dependence is little.

Description

Triaxial resonance capacitance type micro-electromechanical accelerometer

Technical Field

The utility model relates to an accelerometer equipment especially relates to a resonance capacitance formula micro-electromechanical accelerometer of triaxial differential decoupling zero, belongs to little inertial sensor technical field in the MEMS system.

Background

Micro-Electro-Mechanical Systems (MEMS) accelerometer is a common sensor element in MEMS, and has been developed and evolved over nearly half a century since its introduction in the 20 th century 70 s. With the gradual expansion of the application range, the micro-electromechanical accelerometer is also gradually applied to the fields of electronic devices, medical equipment, automobile safety and the like from the earliest limited use in the fields of military and aerospace. Therefore, in order to meet the requirements of different fields on the performance of devices, the micro-electromechanical accelerometer is developed towards miniaturization, low cost and high precision. The current more common microaccelerometers on the market can be classified according to the different sensitivity principles: piezoelectric, piezoresistive, tunneling, capacitive, resonant, etc.

In the prior art, research objects in the field of micro-electromechanical accelerometers mainly focus on two types, namely a capacitive micro-electromechanical accelerometer and a resonant micro-electromechanical accelerometer, and the advantages and the disadvantages of the two types of micro-electromechanical accelerometers in application are obvious. Specifically, the capacitive micro-electromechanical accelerometer is based on an amplitude modulation detection principle, a processing circuit structure of the capacitive micro-electromechanical accelerometer is complex, and the output of the capacitive micro-electromechanical accelerometer is essentially a voltage signal and is easily influenced by parasitic capacitance of an external environment. In order to solve the problem that the capacitive micro-electromechanical Accelerometer is affected by circuit noise due to the amplitude modulation principle, researchers have proposed a frequency modulation micro-electromechanical Accelerometer based on frequency variation of a resonant structure, which is also called a Vibrating Beam Accelerometer (VBA for short). Compared with the capacitive micro-electro-mechanical accelerometer, the sensitive signal output by the VBA is loaded on the working frequency of the sensitive structure before entering a subsequent circuit, so that the influence of gain of each link of the circuit on the output signal is avoided. However, in practical applications, it has been found by those skilled in the art that such devices, which measure by detecting the resonant frequency of a sensitive structure, are highly susceptible to residual stress and environmental changes.

With the rapid improvement of the technological level in recent years, in combination with the above research situation, the requirements on the performance and the use of the micro-electromechanical accelerometer are higher and higher, and particularly, the application demand of the micro-electromechanical accelerometer for three-axis measurement is increased year by year. In the existing operation, for the processing of the three-axis accelerometer, two single-axis or multi-axis micro-electromechanical accelerometers need to be spliced and assembled in a mode that sensitive axes are orthogonally arranged, and then a new three-axis accelerometer is obtained.

In view of the above, in view of the demand of the present market for the use of the micro-electromechanical accelerometer and the common problems of some technical layers, how to design a high-integration and integrated three-axis micro-electromechanical accelerometer becomes a problem to be solved by those skilled in the art.

Disclosure of Invention

In view of the above-mentioned drawbacks of the prior art, the present invention provides a three-axis differential decoupling resonant capacitive micro-electromechanical accelerometer, as follows.

A triaxial resonance capacitance type micro-electro-mechanical accelerometer comprises an upper cover plate layer, a planar structure layer and a lower substrate layer which are sequentially stacked from top to bottom;

the planar structure layer comprises four groups of resonance type micro accelerometers, and the four groups of resonance type micro accelerometers are arranged in a centrosymmetric mode and jointly complete the detection of acceleration in the horizontal direction;

electrode leads are buried in the upper cover plate layer and the lower basal layer and serve as fixed substrates, and the upper cover plate layer and the lower basal layer and the sensitive mass block in the planar structural layer jointly form a differential capacitance type micro-accelerometer for detecting acceleration in the vertical direction.

Preferably, an insulating layer for realizing interlayer separation is arranged between the upper cover plate layer and the planar structure layer and between the planar structure layer and the lower substrate layer, and the planar structure layer is respectively connected with the upper cover plate layer and the lower substrate layer through two insulating layers arranged on the upper surface and the lower surface of the planar structure layer.

Preferably, the upper cover plate layer, the planar structure layer and the lower substrate layer are all manufactured by SOI process; both the upper cover plate layer and the lower substrate layer are made of monocrystalline silicon, and the planar structure layer is made of monocrystalline silicon or polycrystalline silicon.

Preferably, a three-dimensional space coordinate system including an X axis, a Y axis and a Z axis is established with the central point of the planar structure layer as an origin, the X axis and the Y axis are used as horizontal direction references, both of which are parallel to the end face of the planar structure layer, and the Z axis is used as a vertical direction reference and is perpendicular to the end face of the planar structure layer;

the four groups of resonant micro accelerometers are centrosymmetric about an original point, one pair of each two of the four groups of resonant micro accelerometers and two pairs of the four groups of resonant micro accelerometers are symmetrically arranged about an X axis and a Y axis respectively.

Preferably, each group of the resonant micro-accelerometers comprises a sensitive mass block, an inertial force amplification lever structure, a tuning fork resonant structure, a drive detection comb capacitor structure and an anchor point structure;

the sensitive mass block and the anchor point structure are fixedly connected through a plurality of U-shaped beams to jointly form a differential and decoupling detection structure in the X-axis and Y-axis directions.

Preferably, the anchor point structure comprises a central anchor point located at the central position of the planar structural layer and eight peripheral anchor points uniformly distributed at the peripheral positions of the planar structural layer;

the sensitive mass block is integrally in an isosceles trapezoid structure, the upper bottom of the trapezoid faces the central anchor point, one side of the upper bottom of the sensitive mass block is connected with the central anchor point through two symmetrically arranged central U-shaped beams, and one side of the lower bottom of the sensitive mass block is respectively connected with the two peripheral anchor points on the same side through two symmetrically arranged peripheral U-shaped beams.

Preferably, the opening directions of the central U-shaped beam and the peripheral U-shaped beam connected to the sensing mass blocks in the two sets of resonant micro-accelerometers symmetrically arranged along the X-axis direction are both parallel to the Y-axis direction, so that the sensing mass blocks in the two sets of resonant micro-accelerometers symmetrically arranged along the X-axis direction can move along the X-axis direction and the Y-axis direction;

the opening directions of the central U-shaped beam and the peripheral U-shaped beams which are connected with the sensitive mass blocks in the two groups of resonant micro-accelerometers symmetrically arranged along the Y-axis direction are both parallel to the X-axis direction, so that the sensitive mass blocks in the two groups of resonant micro-accelerometers symmetrically arranged along the Y-axis direction can move along the X-axis direction and the Y-axis direction.

Preferably, the inertia force amplifying lever structure, the tuning fork resonance structure and the driving detection comb capacitor structure are all arranged inside the sensitive mass block;

the sensitive mass block is internally provided with an internal central anchor point and two internal peripheral anchor points, the double ends of the tuning fork resonance structure are fixedly supported, one end of the tuning fork resonance structure faces the central anchor point and is connected with the internal central anchor point, and the other end of the tuning fork resonance structure is connected with the sensitive mass block where the tuning fork resonance structure is located through the inertia force amplification lever structure.

Preferably, in two groups of the resonant micro accelerometers symmetrically arranged along the X-axis direction, the whole tuning fork resonant structure is arranged along the X-axis direction, the whole inertia force amplification lever structure is arranged along the Y-axis direction and consists of two levers arranged along the X-axis direction, one end of each lever is connected with one internal peripheral anchor point, and the other end of each lever is connected with the sensitive mass block;

in two sets of resonance formula micro accelerometer that set up along Y axle direction symmetry, tuning fork resonance structure is whole to be set up along Y axle direction, inertia power amplifies that lever structure is whole to be set up along X axle direction just inertia power amplifies lever structure comprises two levers that set up along Y axle direction, one end and one of lever inside peripheral anchor point is connected, the other end with the proof mass piece is connected.

Preferably, the drive detection comb-tooth capacitance structure is arranged on both sides of the tuning fork resonance structure in a mirror symmetry manner, and the drive detection comb-tooth capacitance structure is composed of a drive comb-tooth capacitance and a detection comb-tooth capacitance.

Compared with the prior art, the utility model discloses an advantage mainly embodies in following several aspects:

the utility model provides a triaxial resonance capacitance type micro-electromechanical accelerometer, through adopting in-plane resonant mode to detect X axle, Y axle, the off-plane capacitance type detects the Z axle, and the triaxial all adopts the mode that the difference detected for triaxial total decoupling zero mutual noninterference has characteristics such as high accuracy, high stability, small, the environment dependence is little.

Particularly, the utility model discloses in, the mode that adopts the resonant mode to detect to the acceleration measurement of X axle, Y axle direction is accomplished, compare the capacitanc detection mode among the prior art have stability height, the range is big, measuring accuracy advantage such as high. And simultaneously, the utility model discloses a realize triaxial measuring technological effect, adopt the design of integration, compare the triaxial accelerometer that adopts the mode of concatenation combination to obtain among the prior art have the advantage of miniaturization, easily assembly. Furthermore, the utility model discloses a micro-electromechanical accelerometer all carries out and the decoupling zero of triaxial measurement each other with the mode that the difference detected when carrying out the measurement of triaxial direction to further promote measurement accuracy, reduced the holistic environment dependence of sensor and common mode error.

The utility model discloses also for other technical scheme in the same field provide the reference basis, can extend on this basis, apply to other technical scheme relevant with the micro-electromechanical accelerometer in, specific very high use and spreading value.

The following detailed description is made of specific embodiments of the present invention with reference to the accompanying drawings, so as to make the technical solution of the present invention easier to understand and master.

Drawings

Fig. 1 is a schematic sectional structure of the present invention;

FIG. 2 is a schematic plane structure diagram of the middle plane structure layer of the present invention;

FIG. 3 is a schematic view of the internal structure of the present invention;

wherein: 1. an upper cover plate layer; 2. a planar structural layer; 3. a lower base layer; 4. an insulating layer; 5. a resonant micro accelerometer; 51. a sensing mass; 511. an internal central anchor point; 512. an internal peripheral anchor point; 52. a central anchor point; 53. peripheral anchor points; 54. a central U-shaped beam; 55. a peripheral U-shaped beam; 6. a tuning fork resonant structure; 7. an inertia force amplifying lever structure; 71. a lever; 8. driving and detecting a comb capacitor structure; 81. driving a comb capacitor; 82. and detecting comb capacitance.

Detailed Description

The utility model discloses a resonance capacitance formula micro-electromechanical accelerometer of triaxial differential decoupling zero has overcome a great deal of problems that exist among the prior art effectively, and its structure is specifically as follows.

As shown in fig. 1, a three-axis resonant capacitive micro-electromechanical accelerometer includes an upper cover plate layer 1, a planar structure layer 2, and a lower substrate layer 3, which are sequentially stacked from top to bottom;

the plane structure layer 2 internally comprises four groups of resonance type micro accelerometers 5, and the four groups of resonance type micro accelerometers 5 are arranged in a centrosymmetric manner and jointly complete the detection of acceleration in the horizontal direction;

electrode leads are buried in the upper cover plate layer 1 and the lower base layer 3 to serve as fixed substrates, and the upper cover plate layer 1 and the lower base layer 3 and the sensitive mass block 51 in the planar structure layer 2 jointly form a differential capacitance type micro-accelerometer for detecting acceleration in the vertical direction.

The upper cover plate layer 1 and the planar structure layer 2 and the lower basal layer 3 are both provided with insulating layers 4 for realizing interlayer separation, and the planar structure layer 2 is respectively connected with the upper cover plate layer 1 and the lower basal layer 3 through two layers of the insulating layers arranged on the upper surface and the lower surface of the planar structure layer.

The upper cover plate layer 1, the planar structure layer 2 and the lower substrate layer 3 are all manufactured by SOI technology, and the inside of the device is in a vacuum environment in the processing processes of the upper cover plate layer, the planar structure layer and the lower substrate layer. The upper cover plate layer 1 and the lower substrate layer 3 are both made of monocrystalline silicon, and the material of the planar structure layer 2 can be selected from monocrystalline silicon or polycrystalline silicon according to actual application requirements.

Establishing a three-dimensional space coordinate system comprising an X axis, a Y axis and a Z axis by taking the central point of the plane structural layer 2 as an original point, wherein the X axis and the Y axis are used as horizontal direction references and are both parallel to the end surface of the plane structural layer 2, and the Z axis is used as a vertical direction reference and is vertical to the end surface of the plane structural layer 2;

the four groups of resonance type micro accelerometers 5 are centrosymmetric about an origin, and the four groups of resonance type micro accelerometers 5 are paired pairwise and two pairs of resonance type micro accelerometers 5 are symmetrically arranged about an X axis and a Y axis respectively.

As shown in fig. 2 and 3, each group of resonant micro accelerometers 5 in the planar structure layer 2 has the same structure, and specifically, each group of resonant micro accelerometers 5 includes a sensing mass block 51, an inertial force amplification lever structure 7, a tuning fork resonant structure 6, a drive detection comb capacitor structure 8, and an anchor point structure;

the sensing mass block 51 and the anchor point structure are fixedly connected through a plurality of U-shaped beams to jointly form a differential and decoupling detection structure in the X-axis and Y-axis directions.

The anchor point structure comprises a central anchor point 52 located at the central position of the planar structural layer 2 and eight peripheral anchor points 53 uniformly distributed at the circumferential positions of the planar structural layer 2;

the sensing mass block 51 is of an isosceles trapezoid structure as a whole, the upper bottom of the trapezoid faces the central anchor point 52, one side of the upper bottom of the sensing mass block 51 is connected with the central anchor point 52 through two symmetrically arranged central U-shaped beams 54, and one side of the lower bottom of the sensing mass block 51 is respectively connected with two peripheral anchor points 53 on the same side through two symmetrically arranged peripheral U-shaped beams 55.

It should be noted that the opening directions of the central U-shaped beam 54 and the peripheral U-shaped beam 55 connected to the proof masses 51 in the two sets of resonant micro-accelerometers 5 symmetrically arranged along the X-axis direction are both parallel to the Y-axis direction, so that the proof masses 51 in the two sets of resonant micro-accelerometers 5 symmetrically arranged along the X-axis direction can move along the X-axis direction and the Y-axis direction;

the opening directions of the central U-shaped beam 54 and the peripheral U-shaped beams 55 connected to the proof masses 51 in the two sets of resonant micro-accelerometers 5 symmetrically arranged along the Y-axis direction are both parallel to the X-axis direction, so that the proof masses 51 in the two sets of resonant micro-accelerometers 5 symmetrically arranged along the Y-axis direction can move along the X-axis and Y-axis directions.

The arrangement scheme of the U-shaped beam is that the stiffness of the U-shaped beam in the opening direction of the U-shaped beam is much greater than that of the other two orthogonal directions, so that it can be considered that two of the proof masses 51 arranged along the X-axis direction can only move along the X, Z-axis direction, and two of the proof masses 51 arranged along the Y-axis direction can only move along the Y, Z-axis direction, so as to realize three-axis differential and decoupling output.

The inertia force amplification lever structure 7, the tuning fork resonance structure 6 and the driving detection comb capacitor structure 8 are all arranged inside the sensitive mass block 51;

an internal central anchor point 511 and two internal peripheral anchor points 512 are arranged inside the sensing mass block 51, the two ends of the tuning fork resonant structure 6 are fixedly supported, one end of the tuning fork resonant structure faces the central anchor point 52 and is connected with the internal central anchor point 511, and the other end of the tuning fork resonant structure is connected with the sensing mass block 51 where the tuning fork resonant structure is located through the inertia force amplification lever structure 7.

It should also be noted that, in the two sets of resonant micro accelerometers 5 symmetrically arranged along the X-axis direction, the whole tuning fork resonant structure 6 is arranged along the X-axis direction, the whole inertia force amplification lever structure 7 is arranged along the Y-axis direction, and the inertia force amplification lever structure 7 is composed of two levers 71 arranged along the X-axis direction, one end of each lever 71 is connected with one internal peripheral anchor point 512, and the other end is connected with the sensing mass block 51;

in the two sets of resonant micro accelerometers 5 symmetrically arranged along the Y-axis direction, the tuning fork resonant structure 6 is integrally arranged along the Y-axis direction, the inertia force amplification lever structure 7 is integrally arranged along the X-axis direction, the inertia force amplification lever structure 7 is composed of two levers 71 arranged along the Y-axis direction, one end of each lever 71 is connected with one internal peripheral anchor point 512, and the other end of each lever is connected with the sensitive mass block 51.

The drive detects comb capacitance structure 8 set up in with mirror symmetry's mode in the both sides of tuning fork resonance structure 6, the drive detects comb capacitance structure 8 and comprises drive comb capacitance 81 and detection comb capacitance 82.

As shown in fig. 3, in the driving comb capacitors 81, the comb capacitors individually disposed on one side apply a positive driving voltage S +, and the two comb capacitors disposed on the other side apply a negative driving voltage S —, so as to form a resonant micro-accelerometer driving module; in the detection comb capacitors 82, the comb capacitors arranged on one side alone apply positive detection voltage D +, and the two comb capacitors arranged on the other side in pairs apply negative detection voltage S —, thereby forming a resonant micro-accelerometer detection module.

The technical solution is further explained by the specific explanation of the application principle of the present invention.

The utility model discloses a novel triaxial resonance capacitanc micro-electromechanical accelerometer, its purpose is for detecting the triaxial acceleration and realize difference, decoupling zero measurement.

Two sensitive mass blocks 51 along the X-axis direction are influenced by acceleration to displace, and generate pressure or pressure influence on the internal double-end fixed-support tuning fork through an inertia force amplification lever structure to change the resonance frequency of the tuning fork, wherein the variation is respectively

And

by differential output as

(ii) a The Y axis is the same; four sensing mass blocks 51 along the Z-axis direction are respectively formed with the upper cover plate layer 1 and the lower substrate layer 3When acceleration is input, the four sensitive mass blocks 51 move out of plane along the Z-axis direction, the distance between the four sensitive mass blocks and the upper cover plate layer 1 and the distance between the four sensitive mass blocks and the lower base layer 3 are increased and decreased, and the capacitance variation is respectively

And

by differential output as

。

When acceleration exists along the X-axis direction, the two sensitive mass blocks 51 along the X direction displace along the same direction, the internal tuning fork resonant structure 6 generates tensile force and pressure through the inertia force amplification lever structure 7 respectively, the resonant frequency of the tuning fork resonant structure is changed, one resonant frequency of the tuning fork resonant structure is increased, and the variation is

One resonance frequency becomes small by an amount of change of

The output in the X-axis direction is

(ii) a The two proof masses 51 along the Y-direction are affected by the U-shaped beam, and the stiffness along the X-axis is very large, so the displacement change is almost 0, so that the resonant frequency of the tuning fork resonant structure 6 in the tuning fork resonant structure is not changed, and the output quantity along the Y-axis is

(ii) a The four sensing masses 51 are not displaced along the Z-axis direction, and the distance between the four sensing masses and the upper and lower fixed substrates is not changed, so that the output quantity is

。

When acceleration exists in the Y direction, the output quantity along the Y axis direction is the same as that in the X axis direction

In the X and Z axial directions

，

The output is 0.

When acceleration exists in the Z direction, the four sensitive mass blocks 51 move out of plane along the Z-axis direction, the distances between the four sensitive mass blocks and the upper cover plate layer 1 and the lower substrate layer 3 are increased one by one and are reduced one by one, and the capacitance variation is respectively

And

by differential output as

(ii) a For the in-plane resonant micro accelerometer, the out-of-plane motions of the four sensing masses 51 in the same direction generate the same tensile force or pressure on the tuning fork resonant structure 6 through the inertial force amplifying lever structure, so the resonant frequency changes of the four tuning fork resonant structures 6 are the same, and the outputs of the four tuning fork resonant structures 6 in the X axis and the Y axis are both 0

，

。

From this, realize triaxial resonance capacitanc micro-electromechanical accelerometer's triaxial difference, full decoupling zero detect.

To sum up, the utility model provides a triaxial resonance capacitance type micro-electromechanical accelerometer detects X axle, Y axle through adopting the interior resonant mode of face, and the off-plate capacitance type detects the Z axle, and the triaxial all adopts the mode that the difference detected for triaxial complete decoupling zero mutual noninterference has characteristics such as high accuracy, high stability, small, that the environment dependence is little. Compared with the prior art, the advantages are as follows:

1. the utility model discloses in, the mode that adopts the resonant mode to detect to the acceleration measurement of X axle, Y axle direction is accomplished, compare in the capacitanc detection mode among the prior art have stability height, range big, measurement accuracy advantage such as high.

2. The utility model discloses a realize triaxial measuring technological effect, adopt the design of integration, compare the triaxial accelerometer that adopts the mode of concatenation combination to obtain among the prior art and have the advantage of miniaturization, easily assembly.

3. The utility model discloses a micro-electromechanical accelerometer all carries out and the decoupling zero of triaxial measurement each other with the mode that the difference detected when carrying out the measurement of triaxial direction to further promote measurement accuracy, reduced the holistic environment dependence of sensor and common mode error.

Furthermore, the utility model discloses also for other technical scheme in the same field provide the reference basis, can expand the extension on this basis, apply to in other technical scheme relevant with the micro-electromechanical accelerometer, specific very high use and spreading value.

It is obvious to a person skilled in the art that the invention is not restricted to details of the above-described exemplary embodiments, but that it can be implemented in other specific forms without departing from the spirit or essential characteristics of the invention. The present embodiments are therefore to be considered in all respects as illustrative and not restrictive, the scope of the invention being indicated by the appended claims rather than by the foregoing description, and all changes which come within the meaning and range of equivalency of the claims are therefore intended to be embraced therein, and any reference signs in the claims are not intended to be construed as limiting the claim concerned.

Finally, it should be understood that although the present description refers to embodiments, not every embodiment contains only a single technical solution, and such description is for clarity only, and those skilled in the art should integrate the description, and the technical solutions in the embodiments can be appropriately combined to form other embodiments understood by those skilled in the art.

Claims (10)

1. A triaxial resonance capacitance type micro-electromechanical accelerometer is characterized in that: the laminated composite floor comprises an upper cover plate layer (1), a planar structure layer (2) and a lower base layer (3) which are sequentially laminated from top to bottom;

the plane structure layer (2) comprises four groups of resonance type micro accelerometers (5), and the four groups of resonance type micro accelerometers (5) are arranged in a centrosymmetric mode and jointly complete the detection of acceleration in the horizontal direction;

electrode leads are buried in the upper cover plate layer (1) and the lower base layer (3) and serve as fixed substrates, and the upper cover plate layer (1) and the lower base layer (3) and the sensitive mass block (51) in the plane structure layer (2) jointly form a differential capacitance type micro-accelerometer for detecting acceleration in the vertical direction.

2. The three-axis resonant capacitive micro-electromechanical accelerometer of claim 1, wherein: the top cover plate layer (1) and the plane structure layer (2) and the lower basal layer (3) are both provided with an insulating layer (4) for realizing interlayer separation, the plane structure layer (2) is arranged on the upper surface and the lower surface of the plane structure layer through two layers of the insulating layer, the top cover plate layer (1) and the lower basal layer (3) which are connected.

3. The three-axis resonant capacitive micro-electromechanical accelerometer of claim 1, wherein: the upper cover plate layer (1), the planar structure layer (2) and the lower base layer (3) are all manufactured by an SOI (silicon on insulator) process; both the upper cover plate layer (1) and the lower substrate layer (3) are made of monocrystalline silicon, and the planar structure layer (2) is made of monocrystalline silicon or polycrystalline silicon.

4. The three-axis resonant capacitive micro-electromechanical accelerometer of claim 1, wherein: establishing a three-dimensional space coordinate system comprising an X axis, a Y axis and a Z axis by taking the central point of the plane structural layer (2) as an original point, wherein the X axis and the Y axis are used as horizontal direction references and are both parallel to the end surface of the plane structural layer (2), and the Z axis is used as a vertical direction reference and is vertical to the end surface of the plane structural layer (2);

the four groups of resonance type micro accelerometers (5) are centrosymmetric about an origin, and the four groups of resonance type micro accelerometers (5) are paired in pairs, and the two pairs of resonance type micro accelerometers (5) are symmetrically arranged about an X axis and a Y axis respectively.

5. The three-axis resonant capacitive micro-electromechanical accelerometer of claim 4, wherein: each group of resonant micro accelerometers (5) comprises a sensitive mass block (51), an inertial force amplification lever structure (7), a tuning fork resonant structure (6), a drive detection comb capacitor structure (8) and an anchor point structure;

the sensitive mass block (51) and the anchor point structure are fixedly connected through a plurality of U-shaped beams to jointly form a differential and decoupling detection structure in the X-axis and Y-axis directions.

6. The three-axis resonant capacitive micro-electromechanical accelerometer of claim 5, wherein: the anchor point structure comprises a central anchor point (52) positioned at the central position of the planar structural layer (2) and eight peripheral anchor points (53) uniformly distributed at the circumferential positions of the planar structural layer (2);

the sensing mass block (51) is of an isosceles trapezoid structure as a whole, the upper bottom of the trapezoid faces the central anchor point (52), one side of the upper bottom of the sensing mass block (51) is connected with the central anchor point (52) through two symmetrically arranged central U-shaped beams (54), and one side of the lower bottom of the sensing mass block (51) is respectively connected with two peripheral anchor points (53) on the same side through two symmetrically arranged peripheral U-shaped beams (55).

7. The three-axis resonant capacitive micro-electromechanical accelerometer of claim 6, wherein: the opening directions of the central U-shaped beam (54) and the peripheral U-shaped beam (55) which are connected with the sensitive mass blocks (51) in the two groups of resonant micro-accelerometers (5) symmetrically arranged along the X-axis direction are parallel to the Y-axis direction, so that the sensitive mass blocks (51) in the two groups of resonant micro-accelerometers (5) symmetrically arranged along the X-axis direction can move along the X-axis direction and the Y-axis direction;

the opening directions of the central U-shaped beam (54) and the peripheral U-shaped beam (55) which are connected with the sensitive mass blocks (51) in the two groups of resonant micro-accelerometers (5) symmetrically arranged along the Y-axis direction are parallel to the X-axis direction, so that the sensitive mass blocks (51) in the two groups of resonant micro-accelerometers (5) symmetrically arranged along the Y-axis direction can move along the X-axis direction and the Y-axis direction.

8. The three-axis resonant capacitive micro-electromechanical accelerometer of claim 7, wherein: the inertia force amplification lever structure (7), the tuning fork resonance structure (6) and the driving detection comb capacitor structure (8) are all arranged inside the sensitive mass block (51);

an internal central anchor point (511) and two internal peripheral anchor points (512) are arranged inside the sensitive mass block (51), the double ends of the tuning fork resonant structure (6) are fixedly supported, one end of the tuning fork resonant structure faces the central anchor point (52) and is connected with the internal central anchor point (511), and the other end of the tuning fork resonant structure is connected with the sensitive mass block (51) where the tuning fork resonant structure is located through the inertia force amplification lever structure (7).

9. The three-axis resonant capacitive micro-electromechanical accelerometer of claim 8, wherein: in the two groups of resonant micro accelerometers (5) symmetrically arranged along the X-axis direction, the whole tuning fork resonant structure (6) is arranged along the X-axis direction, the whole inertia force amplification lever structure (7) is arranged along the Y-axis direction, the inertia force amplification lever structure (7) consists of two levers (71) arranged along the X-axis direction, one end of each lever (71) is connected with one internal peripheral anchor point (512), and the other end of each lever is connected with the sensitive mass block (51);

in two sets of resonance type micro accelerometer (5) that set up along Y axle direction symmetry, tuning fork resonant structure (6) are whole to be set up along Y axle direction, inertia power amplifies that lever structure (7) are whole to be set up along X axle direction just inertia power amplifies lever structure (7) and comprises two levers (71) that set up along Y axle direction, the one end of lever (71) with one inside peripheral anchor point (512) are connected, the other end with proof mass (51) are connected.

10. The three-axis resonant capacitive micro-electromechanical accelerometer of claim 9, wherein: the drive detects broach capacitance structure (8) with mirror symmetry's mode set up in the both sides of tuning fork resonance structure (6), the drive detects broach capacitance structure (8) and comprises drive broach capacitance (81) and detection broach capacitance (82).

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