Decoupling and vibration isolation combined beam frame structure shaped like Chinese character'tian 'and high-precision four-mass double-shaft micro-accelerometer thereof

Abstract

The invention discloses a decoupling vibration isolation composite beam frame structure shaped like a Chinese character'tian 'and a high-precision four-mass double-shaft micro-accelerometer thereof. The structure comprises at least four outer ring straight beam mechanisms and at least four decoupling vibration isolation rings. The accelerometer comprises a substrate layer and a device layer, and the device layer comprises the decoupling vibration isolation composite beam frame structure shaped like the Chinese character'tian ', an X-axis dual-mass sensing unit and a Y-axis dual-mass sensing unit. The problem of inter-axis cross coupling of double-axis acceleration detection is solved, isolation and vibration reduction of the MEMS accelerometer to the surrounding environment are achieved, and the influence of temperature and environment vibration on the measurement precision of a device is effectively restrained; by adopting a mode of crosswise arranging the electrode positions, the output error of the MEMS microstructure caused by process mismatch can be effectively inhibited, so that the output precision of the device is improved; each axial direction is designed in a combination mode that double mass sensing unit modules are connected in parallel, so that the detection sensitivity of the device is improved exponentially.

Description

Technical Field

[0001] The invention relates to the technical field of MEMS accelerometers, and in particular to a field-shaped decoupling and vibration-isolating composite beam frame structure and a high-precision four-mass dual-axis micro-accelerometer thereof. Background Art

[0002] With the continuous development of MEMS accelerometer sensing technology, its application scenarios are becoming increasingly diversified. Single-axis accelerometers can no longer meet actual application needs. For example, dual-axis or even multi-axis accelerometers are needed in vehicle safety, unmanned equipment navigation, aircraft attitude control, etc.

[0003] Traditional earlier dual-axis accelerometers mostly use two single-axis accelerometers assembled together in a board-level orthogonal manner. This type of dual-axis micro accelerometer is large in size and has large cross-axis interference errors. The accuracy of dual-axis detection is greatly affected by installation interference. Of course, in the existing MEMS micro accelerometer product technology, there are also device designs that use one structure to simultaneously detect two axial accelerations. This method has the advantages of small size and light weight. However, in applications, there are still output measurement errors caused by process mismatch, low sensitivity, poor signal-to-noise ratio, and other problems. The overall detection accuracy of the micro accelerometer device is not high. Summary of the invention

[0004] The main purpose of the present invention is to address the defects of the prior art. Firstly, through the innovative design of the field-shaped sensitive mass unit basic module and the cross-arrangement of electrode positions, the output error of the MEMS microstructure caused by process mismatch can be effectively suppressed. Secondly, each axial direction adopts a combination design of dual-mass sensitive unit modules in parallel, which will exponentially improve the detection sensitivity of the device. Finally, the overall frame of the device adopts a field-shaped decoupling and vibration isolation composite beam design, so that the four-mass sensitive unit modules are symmetrical and suspended about the center of the structure, and can move independently and cooperatively in their respective sensitive axes, thereby solving the inter-axis cross-coupling problem of dual-axis acceleration detection. At the same time, the frame can realize the isolation and vibration reduction of the MEMS accelerometer from the surrounding environment, effectively suppressing the influence of temperature and environmental vibration on the measurement accuracy of the device, and finally obtaining a field-shaped decoupling and vibration isolation composite beam frame structure and its high-precision four-mass dual-axis micro accelerometer.

[0005] To achieve the above object, one of the technical solutions adopted by the present invention is: a field-shaped decoupling vibration isolation composite beam frame structure, which includes:

[0006] At least four outer ring straight beam mechanisms 1 and at least four decoupling vibration isolation rings 2 work together to isolate and reduce vibration of the surrounding environment, effectively suppressing temperature and environmental vibrations;

[0007] Every four of the outer ring straight beam mechanisms 1 are symmetrical about the center of the structure to form a field shape and are installed on the substrate layer;

[0008] Each of the decoupling vibration isolation rings 2 is installed in the corresponding outer ring straight beam mechanism 1, so that the sensitive units installed on the structure are symmetrical and suspended about the center of the structure, and the sensitive units move independently and cooperatively along their respective sensitive axes, avoiding cross-coupling between axes of dual-axis acceleration detection.

[0009] Furthermore, each of the outer ring straight beam mechanisms 1 includes eight straight beams 101 ; the eight straight beams 101 are connected in pairs to form an L shape and are located at the four corners of the outer ring straight beam mechanism 1 .

[0010] Further, two straight beams 101 located at the four corners of the substrate layer are fixedly mounted on the substrate layer via single mass fixed anchor points 102;

[0011] Four straight beams 101 located at the centers of the four sides of the substrate layer are fixedly mounted on the substrate layer through double mass anchor points 103;

[0012] Eight straight beams 101 located at the center of the substrate layer are fixedly mounted on the substrate layer via four mass fixing anchor points 104 .

[0013] Furthermore, the five sides of each of the decoupling vibration isolation rings 2 are respectively connected to the eight straight beams 101 of the corresponding outer ring straight beam mechanism 1 .

[0014] To achieve the above object, one of the technical solutions adopted by the present invention is: a high-precision four-mass dual-axis micro accelerometer, which is used to detect the acceleration of the navigation device, and the accelerometer includes:

[0015] A substrate layer 3, whose material is silicon;

[0016] The device layer 4 is located above the substrate layer 3 and is fixedly mounted on the substrate layer 3 by corresponding anchors;

[0017] The device layer 4 includes the above-mentioned field-shaped decoupling and vibration isolation composite beam frame structure, the X-axis dual-mass sensitive unit 5 and the Y-axis dual-mass sensitive unit 6;

[0018] The X-axis dual-mass sensitive unit 5 is installed in the upper half of the frame structure of the Chinese-T-shaped decoupling and vibration-isolating composite beam, and the Y-axis dual-mass sensitive unit 6 is installed in the lower half of the frame structure of the Chinese-T-shaped decoupling and vibration-isolating composite beam;

[0019] When there is an acceleration input along the X-axis from the outside, the X-axis dual-mass sensitive unit 5 will be displaced in the X-axis direction, and the capacitance of the X-axis dual-mass sensitive unit 5 will change. Through the control readout of the peripheral circuit, the detection of the X-axis acceleration is completed. Moreover, through the field-shaped decoupling vibration isolation composite beam frame structure, the capacitance of the Y-axis dual-mass sensitive unit 6 is zero, and there is no signal output in the Y-axis direction. It will not be disturbed by the X-axis input and will remain at the zero position.

[0020] When there is an external acceleration input along the Y-axis, the Y-axis dual-mass sensitive unit 6 will be displaced in the Y-axis direction, and the Y-axis dual-mass sensitive unit 6 will produce a capacitance change. Through the control readout of the peripheral circuit, the detection of the Y-axis acceleration is completed. Moreover, through the field-shaped decoupling vibration isolation composite beam frame structure, the capacitance of the X-axis dual-mass sensitive unit 5 is zero, and there is no signal output in the X-axis direction. It will not be disturbed by the Y-axis input and will remain at the zero position.

[0021] Furthermore, the X-axis dual-mass sensitive unit 5 comprises:

[0022] At least two X-axis Chinese-square-shaped single-mass comb tooth frames 501, wherein the two X-axis Chinese-square-shaped single-mass comb tooth frames 501 are respectively located in two outer ring straight beam mechanisms 1 in the upper part;

[0023] At least eight X-axis folded beams 502; each X-axis field-shaped single-mass comb frame 501 is connected to the decoupling vibration isolation ring 2 of the corresponding outer ring straight beam mechanism 1 along the X-axis through the X-axis folded beam 502;

[0024] The X-axis double-mass I-shaped connector 503 is used to connect four adjacent X-axis folding beams 502 to connect two X-axis field-shaped single-mass comb frames 501.

[0025] At least four X-axis positive detection fixed comb tooth frames 504; one end of each X-axis positive detection fixed comb tooth frame 504 is fixedly installed on the bottom layer 3 of the scale through the X-axis positive detection fixed anchor point 505, and the other end is suspended; each X-axis positive detection fixed comb tooth frame 504 is located in the X-axis field-shaped single-quality comb tooth frame 501;

[0026] A plurality of X-axis positive detection fixed comb teeth 506, each of the X-axis positive detection fixed comb teeth 506 is mounted on the X-axis positive detection fixed comb tooth frame 504;

[0027] At least four X-axis negative detection fixed comb tooth frames 507; one end of each X-axis negative detection fixed comb tooth frame 507 is fixedly installed on the bottom layer 3 of the scale through the X-axis negative detection fixed anchor point 510, and the other end is suspended; each X-axis negative detection fixed comb tooth frame 507 is located in the X-axis field-shaped single mass comb tooth frame 501;

[0028] Multiple X-axis negative detection fixed comb teeth 508, each of the X-axis negative detection fixed comb teeth 508 being mounted on the X-axis negative detection fixed comb tooth frame 507;

[0029] Multiple X-axis detection movable comb teeth 509, each of the X-axis detection movable comb teeth 509 being mounted on the X-axis cross-shaped single-mass comb tooth frame 501;

[0030] Wherein, the X-axis positive detection fixed comb teeth 506 and the X-axis detection movable comb teeth 509 are arranged to interleave with each other;

[0031] The X-axis negative detection fixed comb teeth 508 and the X-axis detection movable comb teeth 509 are arranged to interleave with each other.

[0032] Further, the external X-axis acceleration drives the X-axis folding beam 502 to move along the X-axis, driving the X-axis cross-shaped single-mass comb tooth frame 501 to move along the X-axis, and further driving the X-axis detection movable comb teeth 509 to move along the X-axis. The X-axis detection movable comb teeth 509 respectively generate differential capacitance changes with each X-axis positive detection fixed comb tooth 506 、 and the X-axis negative detection fixed comb teeth 508, and the values are read out through the control of the peripheral circuit.

[0033] Further, the Y-axis double-mass sensitive unit 6 includes:

[0034] At least two Y-axis cross-shaped single-mass comb tooth frames 601, the two Y-axis cross-shaped single-mass comb tooth frames 601 being respectively located in the two outer ring straight beam mechanisms 1 in the lower half;

[0035] At least eight Y-axis folding beams 602; each Y-axis cross-shaped single-mass comb tooth frame 601 is connected to the decoupling vibration isolation ring 2 of the corresponding outer ring straight beam mechanism 1 along the Y-axis through the Y-axis folding beam 602;

[0036] A Y-axis double-mass I-shaped connector 603 for connecting four adjacent Y-axis folding beams 602 to connect the two Y-axis cross-shaped single-mass comb tooth frames 601.

[0037] At least four Y-axis positive detection fixed comb tooth frames 604; one end of each Y-axis positive detection fixed comb tooth frame 604 is fixedly mounted on the scale bottom layer through the Y-axis positive detection fixed anchor 605, and the other end is suspended; each Y-axis positive detection fixed comb tooth frame 604 is located within the Y-axis cross-shaped single-mass comb tooth frame 601;

[0038] Multiple Y-axis positive detection fixed comb teeth 606, each of the Y-axis positive detection fixed comb teeth 606 being mounted on the Y-axis positive detection fixed comb tooth frame 604;

[0039] At least four Y-axis negative detection fixed comb tooth frames 607; one end of each Y-axis negative detection fixed comb tooth frame 607 is fixedly installed on the bottom layer of the scale through a Y-axis negative detection fixed anchor point 610, and the other end is suspended; each Y-axis negative detection fixed comb tooth frame 607 is located in a Y-axis field-shaped single-quality comb tooth frame 601;

[0040] A plurality of Y-axis negative detection fixed comb teeth 608, each of the Y-axis negative detection fixed comb teeth 608 is mounted on a Y-axis negative detection fixed comb tooth frame 607;

[0041] A plurality of Y-axis detection movable tooth combs 609, each of which is mounted on a Y-axis field-shaped single-mass comb frame 601;

[0042] Among them, the Y-axis positive detection fixed comb teeth 606 and the Y-axis detection movable comb teeth 609 are arranged interlaced with each other;

[0043] The Y-axis negative detection fixed comb teeth 608 and the Y-axis detection movable comb teeth 609 are arranged to be interlaced with each other.

[0044] Furthermore, the Y-axis folding beam 602 is driven to move along the Y-axis by an external Y-axis acceleration, driving the Y-axis field-shaped single-mass comb frame 601 to move along the Y-axis, thereby driving the Y-axis detection movable comb 609 to move along the Y-axis. The Y-axis detection movable comb 609 is respectively connected to each Y-axis positive detection fixed comb 606. 、 The Y-axis negative detection generates a differential capacitance change between the fixed comb teeth 608, and the value is read out through the control of the peripheral circuit.

[0045] Compared with the prior art, the present invention has the following beneficial effects:

[0046] 1. The present invention can solve the problem of cross-coupling between axes in dual-axis acceleration detection, and can also realize the isolation and vibration reduction of the MEMS accelerometer from the surrounding environment, effectively suppressing the influence of temperature and environmental vibration on the measurement accuracy of the device;

[0047] 2. The cross-arrangement of electrode positions can effectively suppress the output error caused by process mismatch of MEMS microstructure, thereby improving the output accuracy of the device;

[0048] 3. Each axis adopts a dual mass sensitive unit module in parallel, which will multiply the detection sensitivity of the device and further enhance the signal-to-noise ratio of the device;

[0049] 4. The device has high measurement accuracy, small size, easy processing of the overall structure, and can be mass-produced at low cost. BRIEF DESCRIPTION OF THE DRAWINGS

[0050] Figure 1 It is a structural schematic diagram of the field-shaped decoupling and vibration-isolating composite beam frame structure of the present invention;

[0051] Figure 2 It is a structural schematic diagram of a high-precision four-mass dual-axis micro-accelerometer of the present invention;

[0052] Figure 3 It is a structural schematic diagram of the X-axis field-shaped single-mass comb frame of the present invention;

[0053] Figure 4 It is a structural schematic diagram of a Y-axis field-shaped single-mass comb frame of the present invention;

[0054] Figure 5 It is a structural schematic diagram of the X-axis dual-mass sensitive unit of the present invention;

[0055] Figure 6 It is a schematic structural diagram of the Y-axis dual-mass sensitive unit of the present invention.

[0056] In the figure: 1, outer ring straight beam mechanism; 101, straight beam; 102, single mass fixed anchor point; 103, double mass fixed anchor point; 104, four mass fixed anchor point;

[0057] 2. Decoupling vibration isolation ring;

[0058] 3. Substrate layer;

[0059] 4. Device layer;

[0060] 5. X-axis dual-mass sensitive unit; 501. X-axis field-shaped single-mass comb frame; 502. X-axis folding beam; 503. X-axis dual-mass I-shaped connector; 504. X-axis positive detection fixed comb frame; 505. X-axis positive detection fixed anchor point; 506. X-axis positive detection fixed comb teeth; 507. X-axis negative detection fixed comb frame; 508. X-axis negative detection fixed comb teeth; 509. X-axis detection movable comb; 510. X-axis negative detection fixed anchor point;

[0061] 6. Y-axis dual-mass sensitive unit; 601. Y-axis field-shaped single-mass comb tooth frame; 602. Y-axis folding beam; 603. Y-axis dual-mass I-shaped connector; 604. Y-axis positive detection fixed comb tooth frame; 605. Y-axis positive detection fixed anchor point; 606. Y-axis positive detection fixed comb teeth; 607. Y-axis negative detection fixed comb tooth frame; 608. Y-axis negative detection fixed comb teeth; 609. Y-axis detection movable tooth comb; 610. Y-axis negative detection fixed anchor point. DETAILED DESCRIPTION

[0062] In order to enable those skilled in the art to better understand the technical solution of the present invention, the present invention will be further described in detail below with reference to the accompanying drawings.

[0063] Example 1

[0064] like Figure 1 As shown, the zigzag decoupling vibration isolation composite beam frame structure includes:

[0065] At least four outer ring straight beam mechanisms 1 and at least four decoupling vibration isolation rings 2 work together to isolate and reduce vibration of the surrounding environment, effectively suppressing temperature and environmental vibrations;

[0066] Every four of the outer ring straight beam mechanisms 1 are symmetrical about the center of the structure to form a field shape and are installed on the substrate layer;

[0067] Specifically, each of the outer ring straight beam mechanisms 1 includes eight straight beams 101 ; the eight straight beams 101 are connected in pairs to form an L shape and are located at the four corners of the outer ring straight beam mechanism 1 .

[0068] Specifically, two straight beams 101 located at the four corners of the substrate layer are fixedly mounted on the substrate layer through single mass fixed anchor points 102;

[0069] Four straight beams 101 located at the centers of the four sides of the substrate layer are fixedly mounted on the substrate layer through double mass anchor points 103;

[0070] Eight straight beams 101 located at the center of the substrate layer are fixedly mounted on the substrate layer via four mass fixing anchor points 104 .

[0071] Each of the decoupling vibration isolation rings 2 is installed in the corresponding outer ring straight beam mechanism 1, so that the sensitive units installed on the structure are symmetrical and suspended about the center of the structure, and the sensitive units move independently and cooperatively along their respective sensitive axes, avoiding cross-coupling between axes of dual-axis acceleration detection.

[0072] Specifically, the five sides of each of the decoupling vibration isolation rings 2 are respectively connected to the eight straight beams 101 of the corresponding outer ring straight beam mechanism 1 .

[0073] Example 2

[0074] like Figure 2-6 As shown, a high-precision four-mass dual-axis micro accelerometer is used to detect the acceleration of a navigation device. The accelerometer includes:

[0075] A substrate layer 3, whose material is silicon;

[0076] The device layer 4 is located above the substrate layer 3 and is fixedly mounted on the substrate layer 3 by corresponding anchors;

[0077] The device layer 4 includes the field-shaped decoupling and vibration isolation composite beam frame structure, the X-axis dual-mass sensitive unit 5 and the Y-axis dual-mass sensitive unit 6 described in the above embodiment 1;

[0078] The X-axis dual-mass sensitive unit 5 is installed in the upper half of the frame structure of the Chinese-T-shaped decoupling and vibration-isolating composite beam, and the Y-axis dual-mass sensitive unit 6 is installed in the lower half of the frame structure of the Chinese-T-shaped decoupling and vibration-isolating composite beam;

[0079] like Figure 5 As shown, specifically, the X-axis dual-mass sensitive unit 5 includes:

[0080] like Figure 3 As shown, at least two X-axis Chinese-square-shaped single-mass comb tooth frames 501 are respectively located in two outer ring straight beam mechanisms 1 in the upper half;

[0081] At least eight X-axis folded beams 502; each X-axis field-shaped single-mass comb frame 501 is connected to the decoupling vibration isolation ring 2 of the corresponding outer ring straight beam mechanism 1 along the X-axis through the X-axis folded beam 502;

[0082] Specifically, its four square holes are symmetrical about the center of the single-mass basic module. During design, the detection comb teeth are evenly distributed on the tooth comb inside the four square holes, and the positive and negative electrodes are cross-arranged according to the corresponding comb electrodes. This can effectively suppress the output error of the MEMS microstructure caused by process mismatch, thereby optimizing the output accuracy of the device.

[0083] The X-axis double-mass I-shaped connector 503 is used to connect four adjacent X-axis folding beams 502 to connect two X-axis field-shaped single-mass comb frames 501.

[0084] At least four X-axis positive detection fixed comb tooth frames 504; one end of each X-axis positive detection fixed comb tooth frame 504 is fixedly installed on the bottom layer 3 of the scale through the X-axis positive detection fixed anchor point 505, and the other end is suspended; each X-axis positive detection fixed comb tooth frame 504 is located in the X-axis field-shaped single-quality comb tooth frame 501;

[0085] A plurality of X-axis positive detection fixed comb teeth 506, each of the X-axis positive detection fixed comb teeth 506 is mounted on the X-axis positive detection fixed comb tooth frame 504;

[0086] At least four X-axis negative detection fixed comb tooth frames 507; one end of each X-axis negative detection fixed comb tooth frame 507 is fixedly installed on the bottom layer 3 of the scale through the X-axis negative detection fixed anchor point 510, and the other end is suspended; each X-axis negative detection fixed comb tooth frame 507 is located in the X-axis field-shaped single mass comb tooth frame 501;

[0087] A plurality of X-axis negative detection fixed comb teeth 508, each of the X-axis negative detection fixed comb teeth 508 is mounted on an X-axis negative detection fixed comb tooth frame 507;

[0088] Multiple X-axis detection movable comb teeth 509, each of the X-axis detection movable comb teeth 509 is mounted on the X-axis cross-shaped single-mass comb tooth frame 501;

[0089] Among them, the X-axis positive detection fixed comb teeth 506 and the X-axis detection movable comb teeth 509 are arranged in an interpenetrating manner;

[0090] The X-axis negative detection fixed comb teeth 508 and the X-axis detection movable comb teeth 509 are arranged in an interpenetrating manner.

[0091] Specifically, one X-axis positive detection fixed comb tooth 506 and one X-axis detection movable comb tooth 509 form a pair of positive detection capacitors, with a total of N pairs, and the X-axis positive detection electrode is composed of N pairs of positive detection capacitors; one X-axis negative detection fixed comb tooth 508 and one X-axis detection movable comb tooth 509 form a pair of negative detection capacitors, with a total of N pairs, and the X-axis negative detection electrode is composed of N pairs of positive detection capacitors; through this parallel combination design, the acceleration detection sensitivity of the device in the X-axis direction will be doubled.

[0092] Of course, there are various ways to detect acceleration using comb tooth differential capacitors, including open-loop detection, closed-loop detection, adding a separate detection feedback electrode, etc.

[0093] Such as Figure 6 As shown, specifically, the Y-axis dual-mass sensitive unit 6 includes:

[0094] Such as Figure 4 As shown, at least two Y-axis cross-shaped single-mass comb tooth frames 601, and the two Y-axis cross-shaped single-mass comb tooth frames 601 are respectively located in the two outer ring straight beam mechanisms 1 in the lower half;

[0095] At least eight Y-axis folding beams 602; each Y-axis cross-shaped single-mass comb tooth frame 601 is connected to the decoupling vibration isolation ring 2 of the corresponding outer ring straight beam mechanism 1 along the Y-axis through the Y-axis folding beam 602;

[0096] Specifically, its four square holes are centrosymmetric about the center of the single-mass base module. When designing, detection comb teeth are evenly distributed on the comb teeth inside the four square holes, and positive and negative electrode cross arrangements are made according to the corresponding comb tooth electrodes, which can effectively suppress the output error caused by process mismatch of the MEMS microstructure, thereby optimizing the output accuracy of the device.

[0097] The Y-axis dual-mass I-shaped connector 603 is used to connect four adjacent Y-axis folding beams 602 to connect the two Y-axis cross-shaped single-mass comb tooth frames 601.

[0098] At least four Y-axis positive detection fixed comb tooth frames 604; one end of each Y-axis positive detection fixed comb tooth frame 604 is fixedly installed on the bottom layer of the scale through a Y-axis positive detection fixed anchor point 605, and the other end is suspended; each Y-axis positive detection fixed comb tooth frame 604 is located in the Y-axis field-shaped single-quality comb tooth frame 601;

[0099] A plurality of Y-axis positive detection fixed comb teeth 606, each of the Y-axis positive detection fixed comb teeth 606 is mounted on a Y-axis positive detection fixed comb tooth frame 604;

[0100] At least four Y-axis negative detection fixed comb tooth frames 607; one end of each Y-axis negative detection fixed comb tooth frame 607 is fixedly installed on the bottom layer of the scale through a Y-axis negative detection fixed anchor point 610, and the other end is suspended; each Y-axis negative detection fixed comb tooth frame 607 is located in a Y-axis field-shaped single-quality comb tooth frame 601;

[0101] A plurality of Y-axis negative detection fixed comb teeth 608, each of the Y-axis negative detection fixed comb teeth 608 is mounted on a Y-axis negative detection fixed comb tooth frame 607;

[0102] A plurality of Y-axis detection movable tooth combs 609, each of which is mounted on a Y-axis field-shaped single-mass comb frame 601;

[0103] Among them, the Y-axis positive detection fixed comb teeth 606 and the Y-axis detection movable comb teeth 609 are arranged interlaced with each other;

[0104] The Y-axis negative detection fixed comb teeth 608 and the Y-axis detection movable comb teeth 609 are arranged to be interlaced with each other.

[0105] Specifically, a Y-axis positive detection fixed comb tooth 606 and a Y-axis detection movable comb tooth 609 form a pair of positive detection capacitors, with a total of N pairs, and the N pairs of positive detection capacitors form a Y-axis positive detection electrode; a Y-axis negative detection fixed comb tooth 608 and a Y-axis detection movable comb tooth 609 form a pair of negative detection capacitors, with a total of N pairs, and the N pairs of negative detection capacitors form a Y-axis negative and positive detection electrodes; through this parallel combination design, the acceleration detection sensitivity of the device in the Y-axis direction will be multiplied.

[0106] Of course, there are many ways to use comb-tooth differential capacitance to detect acceleration, including open-loop detection, closed-loop detection, adding a separate detection feedback electrode, etc.

[0107] Its working process: when there is an acceleration input along the X-axis from the outside, the X-axis dual-mass sensitive unit 5 will be displaced in the X-axis direction, and the X-axis dual-mass sensitive unit 5 will produce a capacitance change, which is read out through the control of the peripheral circuit to complete the detection of the X-axis acceleration, and through the field-shaped decoupling vibration isolation composite beam frame structure, the Y-axis dual-mass sensitive unit 6 has zero capacitance, no signal output in the Y-axis direction, and will not be disturbed by the X-axis input and remain at the zero position;

[0108] Specifically, the X-axis folding beam 502 is driven to move along the X-axis by an external X-axis acceleration, driving the X-axis field-shaped single-mass comb frame 501 to move along the X-axis, and then driving the X-axis detection movable comb 509 to move along the X-axis. The X-axis detection movable comb 509 is respectively connected to each X-axis positive detection fixed comb 506. 、 The X-axis negative detection generates a differential capacitance change between the fixed comb teeth 508, and the value is read out through the control of the peripheral circuit.

[0109] When there is an external acceleration input along the Y-axis, the Y-axis dual-mass sensitive unit 6 will be displaced in the Y-axis direction, and the Y-axis dual-mass sensitive unit 6 will produce a capacitance change. Through the control readout of the peripheral circuit, the detection of the Y-axis acceleration is completed. Moreover, through the field-shaped decoupling vibration isolation composite beam frame structure, the capacitance of the X-axis dual-mass sensitive unit 5 is zero, and there is no signal output in the X-axis direction. It will not be disturbed by the Y-axis input and will remain at the zero position.

[0110] Specifically, the Y-axis folding beam 602 is driven to move along the Y-axis by an external Y-axis acceleration, driving the Y-axis field-shaped single-mass comb frame 601 to move along the Y-axis, and then driving the Y-axis detection movable comb 609 to move along the Y-axis. The Y-axis detection movable comb 609 is respectively connected to each Y-axis positive detection fixed comb 606. 、 The Y-axis negative detection generates a differential capacitance change between the fixed comb teeth 608, and the value is read out through the control of the peripheral circuit.

[0111] The above shows and describes the basic principles, main features and advantages of the present invention. Those skilled in the art should understand that the present invention is not limited by the above embodiments. The above embodiments and descriptions are only preferred examples of the present invention and are not intended to limit the present invention. Without departing from the spirit and scope of the present invention, the present invention may have various changes and improvements, which fall within the scope of the present invention. The scope of protection of the present invention is defined by the attached claims and their equivalents.

Claims

1. The field-shaped decoupling and vibration-isolating composite beam frame structure is characterized by: The structure includes: At least four outer ring straight beam mechanisms (1) and at least four decoupling vibration isolation rings (2) work together to isolate and reduce vibration of the surrounding environment, thereby effectively suppressing temperature and environmental vibrations; Every four of the outer ring straight beam mechanisms (1) are symmetrical about the center of the structure to form a field shape and are installed on the substrate layer; Each of the decoupling vibration isolation rings (2) is installed in a corresponding outer ring straight beam mechanism (1), so that the sensitive units installed on the structure are symmetrical and suspended about the center of the structure, and the sensitive units move independently and cooperatively along their respective sensitive axes, thereby avoiding cross-coupling between axes of dual-axis acceleration detection.

2. The field-shaped decoupling and vibration-isolating composite beam frame structure according to claim 1 is characterized in that: Each of the outer ring straight beam mechanisms (1) comprises eight straight beams (101); the eight straight beams (101) are connected in pairs to form an L shape and are located at the four corners of the outer ring straight beam mechanism (1).

3. The field-shaped decoupling and vibration-isolating composite beam frame structure according to claim 2 is characterized in that: Two straight beams (101) located at the four corners of the substrate layer are fixedly mounted on the substrate layer via single mass fixed anchor points (102); Four straight beams (101) located at the centers of the four sides of the substrate layer are fixedly mounted on the substrate layer via double mass fixed anchor points (103); Eight straight beams (101) located at the center of the substrate layer are fixedly mounted on the substrate layer via four mass fixing anchor points (104).

4. The field-shaped decoupling and vibration-isolating composite beam frame structure according to claim 3 is characterized in that: The five sides of each decoupling vibration isolation ring (2) are respectively connected to the eight straight beams (101) of the corresponding outer ring straight beam mechanism (1).

5. A high-precision four-mass dual-axis micro accelerometer, which is used to detect the acceleration of a navigation device, characterized in that: The accelerometer includes: A substrate layer (3) made of silicon; A device layer (4), which is located above the substrate layer (3) and is fixedly mounted on the substrate layer (3) by corresponding anchors; The device layer (4) includes the Chinese-T-shaped decoupling and vibration-isolating composite beam frame structure, the X-axis dual-mass sensitive unit (5) and the Y-axis dual-mass sensitive unit (6) as described in claim 4; The X-axis dual-mass sensitive unit (5) is installed in the upper part of the field-shaped decoupling and vibration-isolating composite beam frame structure, and the Y-axis dual-mass sensitive unit (6) is installed in the lower part of the field-shaped decoupling and vibration-isolating composite beam frame structure.

6. The high-precision four-mass dual-axis micro-accelerometer according to claim 5, characterized in that: When there is an external acceleration input along the X-axis, the X-axis dual-mass sensitive unit (5) will be displaced in the X-axis direction, and the X-axis dual-mass sensitive unit (5) will produce a capacitance change, which is read out through the control of the peripheral circuit to complete the detection of the X-axis acceleration, and through the field-shaped decoupling vibration isolation composite beam frame structure, the capacitance of the Y-axis dual-mass sensitive unit (6) is zero, and there is no signal output in the Y-axis direction, and it will not be disturbed by the X-axis input and remain at the zero position; When there is an external acceleration input along the Y-axis, the Y-axis dual-mass sensitive unit (6) will be displaced in the Y-axis direction, and the Y-axis dual-mass sensitive unit (6) will produce a capacitance change, which is read out through the control of the peripheral circuit to complete the detection of the Y-axis acceleration, and through the field-shaped decoupling vibration isolation composite beam frame structure, the capacitance of the X-axis dual-mass sensitive unit (5) is zero, there is no signal output in the X-axis direction, and it will not be disturbed by the Y-axis input and remain at the zero position.

7. The high-precision four-mass dual-axis micro-accelerometer according to claim 6, characterized in that: The X-axis dual mass sensitive unit (5) comprises: At least two X-axis Chinese-square-shaped single-mass comb tooth frames (501), the two X-axis Chinese-square-shaped single-mass comb tooth frames (501) being respectively located in two outer ring straight beam mechanisms (1) of the upper half; At least eight X-axis folded beams (502); each X-axis field-shaped single-mass comb frame (501) is connected to a decoupling vibration isolation ring (2) of a corresponding outer ring straight beam mechanism (1) along the X-axis direction via the X-axis folded beam (502); The X-axis double-mass I-shaped connector (503) is used to connect four adjacent X-axis folding beams (502) to connect two X-axis field-shaped single-mass comb tooth frames (501). At least four X-axis positive detection fixed comb tooth frames (504); one end of each X-axis positive detection fixed comb tooth frame (504) is fixedly mounted on the bottom layer (3) of the scale through an X-axis positive detection fixed anchor point (505), and the other end is suspended in the air; each X-axis positive detection fixed comb tooth frame (504) is located in an X-axis field-shaped single-mass comb tooth frame (501); A plurality of X-axis positive detection fixed comb teeth (506), each of the X-axis positive detection fixed comb teeth (506) being mounted on an X-axis positive detection fixed comb tooth frame (504); At least four X-axis negative detection fixed comb tooth frames (507); one end of each X-axis negative detection fixed comb tooth frame (507) is fixedly mounted on the bottom layer (3) of the scale through an X-axis negative detection fixed anchor point (510), and the other end is suspended in the air; each X-axis negative detection fixed comb tooth frame (507) is located in the X-axis field-shaped single-mass comb tooth frame (501); A plurality of X-axis negative detection fixed comb teeth (508), each of the X-axis negative detection fixed comb teeth (508) being mounted on an X-axis negative detection fixed comb tooth frame (507); A plurality of X-axis detection movable tooth combs (509), each of the X-axis detection movable tooth combs (509) being mounted on an X-axis field-shaped single-mass comb tooth frame (501); Wherein, the X-axis positive detection fixed comb teeth (506) and the X-axis detection movable comb teeth (509) are arranged to intersect each other; The X-axis negative detection fixed comb teeth (508) and the X-axis detection movable comb teeth (509) are arranged to intersect each other.

8. The high-precision four-mass dual-axis micro-accelerometer according to claim 7, characterized in that: The X-axis folding beam (502) is driven to move along the X-axis by an external X-axis acceleration, thereby driving the X-axis field-shaped single-mass comb frame (501) to move along the X-axis, thereby driving the X-axis detection movable comb (509) to move along the X-axis, and the X-axis detection movable comb (509) is respectively connected to each X-axis positive detection fixed comb (506) 、 A differential capacitance change is generated between the X-axis negative detection fixed comb teeth (508), and the value is read out through the control of the peripheral circuit.

9. The high-precision four-mass dual-axis micro-accelerometer according to claim 6, characterized in that: The Y-axis dual-mass sensitive unit (6) comprises: At least two Y-axis Chinese-square-shaped single-mass comb tooth frames (601), the two Y-axis Chinese-square-shaped single-mass comb tooth frames (601) being respectively located in two outer ring straight beam mechanisms (1) in the lower half; At least eight Y-axis folding beams (602); each Y-axis field-shaped single-mass comb frame (601) is connected to a decoupling vibration isolation ring (2) of a corresponding outer ring straight beam mechanism (1) along the Y-axis through the Y-axis folding beam (602); The Y-axis double-mass I-shaped connector (603) is used to connect four adjacent Y-axis folding beams (602) to connect two Y-axis field-shaped single-mass comb frames (601). At least four Y-axis positive detection fixed comb tooth frames (604); one end of each Y-axis positive detection fixed comb tooth frame (604) is fixedly mounted on the bottom layer (3) of the scale through a Y-axis positive detection fixed anchor point (605), and the other end is suspended in the air; each Y-axis positive detection fixed comb tooth frame (604) is located in a Y-axis field-shaped single-mass comb tooth frame (601); A plurality of Y-axis positive detection fixed comb teeth (606), each of the Y-axis positive detection fixed comb teeth (606) being mounted on a Y-axis positive detection fixed comb tooth frame (604); At least four Y-axis negative detection fixed comb tooth frames (607); one end of each Y-axis negative detection fixed comb tooth frame (607) is fixedly mounted on the bottom layer (3) of the scale through a Y-axis negative detection fixed anchor point (610), and the other end is suspended in the air; each Y-axis negative detection fixed comb tooth frame (607) is located in a Y-axis field-shaped single-mass comb tooth frame (601); A plurality of Y-axis negative detection fixed comb teeth (608), each of the Y-axis negative detection fixed comb teeth (608) being mounted on a Y-axis negative detection fixed comb tooth frame (607); A plurality of Y-axis detection movable tooth combs (609), each of the Y-axis detection movable tooth combs (609) is mounted on a Y-axis field-shaped single-mass comb tooth frame (601); Wherein, the Y-axis positive detection fixed comb teeth (606) and the Y-axis detection movable comb teeth (609) are arranged to intersect each other; The Y-axis negative detection fixed comb teeth (608) and the Y-axis detection movable comb teeth (609) are arranged to intersect each other.

10. The high-precision four-mass dual-axis micro-accelerometer according to claim 9, characterized in that: The Y-axis folding beam (602) is driven to move along the Y-axis by an external Y-axis acceleration, thereby driving the Y-axis field-shaped single-mass comb frame (601) to move along the Y-axis, thereby driving the Y-axis detection movable comb (609) to move along the Y-axis, and the Y-axis detection movable comb (609) is respectively connected to each Y-axis positive detection fixed comb (606) 、 The Y-axis negative detection generates a differential capacitance change between the fixed comb teeth (608), and the value is read out through the control of the peripheral circuit.

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