A MEMS capacitive sensor
By employing a differential capacitor structure and a temperature coefficient compensation layer in the MEMS capacitive sensor, the problems of temperature drift and high cross-axis sensitivity are solved, achieving higher measurement accuracy and stability.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Utility models(China)
- Current Assignee / Owner
- RAYTRON(WUXI) TECH CO LTD
- Filing Date
- 2025-07-07
- Publication Date
- 2026-06-30
AI Technical Summary
Existing MEMS capacitive vibration sensors suffer from high temperature drift coefficients and cross-axis sensitivity, which affect sensor performance.
The movable and fixed comb teeth, arranged in a mass frame and fixed structure, are staggered to form a differential capacitor. The differential output technology reduces the capacitance change caused by vibration or acceleration of non-detected axes, and a temperature coefficient compensation layer is set on the elastic beam to offset thermal stress deformation.
It effectively reduces the cross-axis sensitivity and temperature drift of the sensor, and improves the sensor's performance, especially in the accuracy and stability of low-frequency vibration signal measurement.
Smart Images
Figure CN224435638U_ABST
Abstract
Description
Technical Field
[0001] This utility model relates to the field of microelectromechanical technology, and more specifically to a MEMS capacitive sensor. Background Technology
[0002] Vibration sensors are devices that detect external vibration signals. Traditional vibration sensors typically use piezoelectric materials as the sensing material, which can relatively easily achieve a wide frequency measurement bandwidth of over 10 kHz. However, piezoelectric vibration sensors cannot measure DC signals and are also bulky and expensive.
[0003] With the continuous development of MEMS technology, MEMS capacitive vibration sensors have achieved significant improvements in measurement bandwidth and noise levels, and their key performance indicators are approaching those of piezoelectric sensors. Moreover, due to the adoption of mass-production semiconductor manufacturing technology, MEMS capacitive vibration sensors can achieve smaller size, lower cost, and higher mass production consistency, and their measurement frequency band can cover low-frequency vibration signals down to DC.
[0004] MEMS (Micro-Electro-Mechanical Systems) are miniature systems that integrate multiple functions such as micro-sensors, actuators, signal processing, and control circuits. Their feature sizes are typically on the micrometer or even nanometer scale. They are a product of the combination of microelectronics and mechanical engineering, using microfabrication techniques to integrate mechanical components and electronic circuits onto a single chip to achieve specific functions.
[0005] In addition to the usual range, sensitivity, and accuracy, key performance indicators for MEMS capacitive sensors include temperature drift coefficient and cross-axis sensitivity. The temperature coefficient of the elastic modulus of silicon is approximately -60 ppm / ℃, which directly causes temperature drift in sensor sensitivity. Cross-axis sensitivity represents the effect of vibration or acceleration signals from sources other than the measurement axis on the output. Theoretically, the closer to zero, the better; however, in practice, due to design and manufacturing deviations, conventional sensors can only achieve 1% to 3% cross-axis sensitivity.
[0006] Therefore, how to effectively reduce the temperature drift coefficient and cross-axis sensitivity, and improve the performance of the sensor, is a technical problem that needs to be solved. Utility Model Content
[0007] The core of this invention is to provide a MEMS capacitive sensor. Movable comb teeth in the mass frame and fixed comb teeth in the fixed structure are spaced apart and interleaved to form a differential capacitor, resulting in a differential output. This differentially eliminates the capacitance change caused by vibration or acceleration of non-detected axes, preventing signal output and significantly reducing the sensor's cross-axis sensitivity and minimizing the impact of vibration on non-detected axes. The specific solution is as follows:
[0008] A MEMS capacitive sensor, comprising:
[0009] Anchor points are fixed in place.
[0010] An elastic beam extends in a straight line along a first direction, with one end fixed to an anchor point;
[0011] An inner frame surrounds the anchor point and is fixedly connected to the other end of the elastic beam to form a suspended structure;
[0012] A connecting beam extends in a straight line along the second direction, with one end fixed to the inner frame;
[0013] A mass frame is fixed to the other end of the connecting beam to form a suspension. The mass frame and the inner frame are distributed side by side along the second direction. A set of movable comb teeth is provided on each of the two opposite sidewalls inside the mass frame.
[0014] A fixed structure, a fixed arrangement, wherein two fixed structures are relatively insulated and arranged within a range enclosed by the mass frame; each fixed structure is provided with a set of fixed comb teeth;
[0015] Wherein, the first direction and the second direction are perpendicular to each other; the two sets of movable comb teeth and the two sets of fixed comb teeth are interleaved and cooperated to form a differential capacitor.
[0016] Optionally, the elastic beam includes two sets, with the two sets of elastic beams located on both sides of the anchor point along the first direction.
[0017] Optionally, each set of elastic beams includes two straight beams or folded beams arranged side by side.
[0018] Optionally, a stop structure is provided between the mass frame and the fixed structure, and the stop structure is provided at both ends of the fixed structure along the first direction;
[0019] The stop structure is fixedly installed and is used to limit the extreme positions of the mass frame's movement along the first direction.
[0020] Optionally, the connecting beam is fixedly connected to both ends of the mass frame along the first direction and is located at a position away from the inner frame.
[0021] Optionally, the movable comb teeth and the fixed comb teeth are rectangular or trapezoidal in shape.
[0022] Optionally, the inner frame is symmetrically provided with the connecting beam, the mass frame, the fixed structure, the movable comb teeth, and the fixed comb teeth on both sides along the second direction.
[0023] Optionally, a temperature coefficient compensation layer is provided on the outer surface of the elastic beam, and the thermal deformation amplitude of the temperature coefficient compensation layer cancels out the thermal deformation amplitude of the elastic beam.
[0024] Optionally, the temperature coefficient compensation layer is disposed on the upper and / or lower surface of the elastic beam.
[0025] This invention provides a MEMS capacitive sensor with fixed anchor points and a fixed structure. An elastic beam and a connecting beam are perpendicular to each other. The anchor points support the inner frame via the elastic beam, making the inner frame suspended. The inner frame, in turn, supports the mass frame via the connecting beam, making the mass fixed structure frame suspended. Movable comb teeth on the mass frame and fixed comb teeth on the fixed structure are spaced and interleaved to form a differential capacitor. The movable and fixed comb teeth use differential output, which can differentially eliminate the capacitance changes caused by vibration or acceleration of non-detected axes, preventing signal output. This helps reduce the sensor's cross-axis sensitivity and improve sensor performance. Attached Figure Description
[0026] To more clearly illustrate the technical solutions in the embodiments of this utility model or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of this utility model. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.
[0027] Figure 1 This is a schematic diagram of the structure of the MEMS capacitive sensor of this utility model;
[0028] Figure 2 for Figure 1 A simplified diagram showing the four differential capacitors formed in the structure shown.
[0029] Figure 3 for Figure 1 A cross-sectional view along the AA direction, illustrating a schematic diagram of a temperature coefficient compensation layer for an elastic beam.
[0030] The image includes:
[0031] Anchor point 10, elastic beam 20, temperature coefficient compensation layer 201, inner frame 30, connecting beam 40, mass frame 50, movable comb teeth 501, fixed structure 60, fixed comb teeth 601, stop structure 70. Detailed Implementation
[0032] To enable those skilled in the art to better understand the technical solution of this utility model, the MEMS capacitive sensor of this utility model will be described in detail below with reference to the accompanying drawings and specific embodiments.
[0033] The MEMS capacitive sensor of this invention uses movable comb teeth 501 and fixed comb teeth 601 to form a differential capacitor through alternating intervals. Vibrations in the non-measurement direction (Y-axis) are canceled out by the two differential capacitors, reducing interference from the non-measurement direction to the detection in the measurement direction (X-axis). In this paper, the first direction is along the Y-axis, the second direction is along the X-axis, and the first and second directions are perpendicular to each other.
[0034] This invention provides a MEMS capacitive sensor, including an anchor point 10, an elastic beam 20, an inner frame 30, a connecting beam 40, a mass frame 50, and a fixing structure 60. The anchor point 10 is fixedly installed, and a support structure can be installed below the anchor point 10 to support it. The anchor point 10 can be rectangular or other shapes. The thickness (Z-axis) of the anchor point 10, elastic beam 20, inner frame 30, connecting beam 40, mass frame 50, and fixing structure 60 are approximately equal.
[0035] The elastic beam 20 extends in a straight line along the first direction, with one end fixed to the anchor point 10; combined with Figure 1 As shown, the elastic beam 20 extends along the Y-axis in its length direction. Figure 1 The beam extends vertically, with anchor point 10 fixing one end of the elastic beam 20 and inner frame 30 fixing the other end of the elastic beam 20.
[0036] The inner frame 30 is a ring-shaped structure, which can be a rectangular ring or other ring shapes. A hollowed-out section is provided in the middle of the inner frame 30, and the space in the middle of the inner frame 30 is larger than or completely accommodates the anchor point 10. The inner frame 30 surrounds the anchor point 10, as seen from a top view (…). Figure 1 (View from the outside), the inner frame 30 surrounds the anchor point 10 from all sides, and there is space between the inner frame 30 and the anchor point 10. When the inner frame 30 moves relative to the anchor point 10, it will not contact the anchor point 10.
[0037] The inner frame 30 is fixedly connected to one end of the elastic beam 20, forming a suspended state. That is, the anchor point 10 supports the inner frame 30 through the elastic beam 20, making the inner frame 30 suspended. The lower surface of the inner frame 30 has no supporting structure. The elastic beam 20 has greater stiffness in the Y-axis direction (first direction), and the elastic beam 20 can be considered fixed in the Y-axis direction, while the elastic beam 20 can move relative to the anchor point 10 in the X-axis direction.
[0038] The connecting beam 40 extends in a straight line along the second direction (X-axis). One end of the connecting beam 40 is fixed to the inner frame 30, and the other end of the connecting beam 40 is fixed to the mass frame 50. The inner frame 30 supports the mass frame 50 through the connecting beam 40.
[0039] Due to its relatively large mass, the mass frame 50 is primarily used to sense external vibration or acceleration signals. The mass frame 50 is fixed to the other end of the connecting beam 40, forming a suspended state. There is no supporting structure below the mass frame 50; it is supported only by the connecting beam 40. Similar to the inner frame 30, the mass frame 50 is also a centrally hollowed-out annular frame structure. A fixed structure 60 is located in the middle of the mass frame 50, with a gap between the mass frame 50 and the fixed structure 60, ensuring that the mass frame 50 does not contact the fixed structure 60 during movement.
[0040] The mass frame 50 and the inner frame 30 are arranged side by side along the second direction (X-axis), combined with Figure 1 As shown, the mass frame 50 and the inner frame 30 are distributed at left and right intervals, and there is a certain gap between the mass frame 50 and the inner frame 30.
[0041] The connecting beam 40 extends along the X-axis. The connecting beam 40 has greater stiffness in the X-axis direction. Therefore, the mass frame 50 and the inner frame 30 can be regarded as moving synchronously in the X-axis direction. The connecting beam 40 can bend and elastically deform in the Y-axis direction. Therefore, the mass frame 50 can move relative to the inner frame 30 along the Y-axis.
[0042] A set of movable comb teeth 501 is respectively provided on the two opposite sidewalls inside the mass frame 50, combined with Figure 1 As shown, several movable comb teeth 501 are arranged at intervals on the inner sidewalls of the left and right sides of the mass frame 50. The movable comb teeth 501 are fixed on the mass frame 50 and can move with the mass frame 50.
[0043] The fixed structure 60 is fixedly installed, and a supporting structure can be installed below the fixed structure 60 to support the fixed structure 60.
[0044] The mass frame 50 is a ring-shaped frame structure. Within the area enclosed by the mass frame 50, two fixed structures 60 are relatively insulated and arranged together. Figure 1 As shown, there is an insulating gap between the two fixed structures 60. Each fixed structure 60 is provided with a set of fixed comb teeth 601, which are fixedly mounted on the fixed structure 60 and remain fixed at all times.
[0045] Two sets of movable comb teeth 501 and two sets of fixed comb teeth 601 are staggered and interleaved to form a differential capacitor, combined with Figure 2As shown, the two sets of movable comb teeth 501 and the two sets of fixed comb teeth 601 on the left side cooperate to form capacitors C1 and C2, respectively, while the two sets of movable comb teeth 501 and the two sets of fixed comb teeth 601 on the right side cooperate to form capacitors C3 and C4, respectively. Capacitors C1 and C2 form a differential capacitor pair, and capacitors C3 and C4 form a differential capacitor pair. The detection signal is output differentially, and the signal output in the non-detection direction (Y-axis) is canceled out by the differential.
[0046] When vibration or acceleration in the X direction (detection axis) acts on the entire sensor structure, due to the stiffness design of the elastic beam 20 and connecting beam 40, the inner frame 30 and mass frame 50 will simultaneously displace along the X direction, causing a change in the overlap area of the movable comb teeth 501 and the fixed comb teeth 601, resulting in a change in capacitance. The fixed comb teeth 601 on the fixed structure 60 are used for differential detection with the movable comb teeth 501, which can amplify the signal under test and suppress common-mode interference signals, thus helping to improve the signal-to-noise ratio.
[0047] When vibration or acceleration in the Y direction (non-detection axis) acts on the entire sensor structure, the mass frame 50 will move a certain distance along the Y direction due to the stiffness design of the elastic beam 20 and the connecting beam 40. However, due to the differential output design of the movable comb tooth 501 and the fixed comb tooth 601, the change in capacitance can be differentially eliminated, and no signal is output.
[0048] When vibration or acceleration in the Z direction (non-detection axis) acts on the entire sensor structure, due to the stiffness design of the elastic beam 20 and the connecting beam 40, the inner frame 30 and the mass frame 50 will simultaneously move along the Z direction, and all capacitors will change by the same amount. The differential design of the capacitor output can differentiate the amount of change in capacitance and not output a signal.
[0049] This application uses mutually perpendicular elastic beams 20 and connecting beams 40 to keep the inner frame 30 and mass frame 50 suspended. The mass frame 50 can be displaced relative to the fixed structure 60. Two sets of fixed comb teeth 601 and two sets of movable comb teeth 501 cooperate to form a differential capacitor for differential output. This can differentiate the capacitance change caused by vibration or acceleration of non-detected axes, and prevent signal output, which helps to reduce the cross-axis sensitivity of the sensor.
[0050] Based on the above scheme, the elastic beam 20 of this utility model includes two sets, with the two sets of elastic beams 20 located on both sides of the anchor point 10 along the first direction. Combined with... Figure 1 As shown, two sets of elastic beams 20 are respectively set above and below the anchor point 10. The two sets of elastic beams 20 are symmetrically distributed vertically, with the axis of symmetry parallel to the X-axis and passing through the midpoint of the anchor point 10. The inner frame 30 is supported by the two sets of elastic beams 20.
[0051] Each set of elastic beams 20 includes two straight beams or folded beams arranged side by side. Figure 1 The diagram shows the elastic beam 20 as a straight beam structure. The elastic beam 20 can also be a folded beam. The elastic beam 20 extends along... Figure 1 The stiffness along the X-axis is relatively low, while the stiffness along the Y-axis is relatively high. Connecting beam 40 can be as follows: Figure 1 The straight beam shown could also be a folded beam, with connecting beam 40 along... Figure 1 The stiffness is greater in the X direction and less in the Y direction shown in the figure.
[0052] Combination Figure 1 As shown, a stop structure 70 is provided between the mass frame 50 and the fixed structure 60. The stop structure 70 is fixedly installed, and a support structure is provided below the stop structure 70. Stop structures 70 are respectively provided at both ends of the fixed structure 60 along the first direction, and at least two stop structures 70 should be provided. There is a Y-axis distance between the stop structure 70 and the mass frame 50, and a Y-axis distance between the stop structure 70 and the fixed structure 60. The stop structure 70 is used to limit the extreme position of the mass frame 50's movement along the first direction. When the mass frame 50 moves along the Y-axis and contacts the stop structure 70, it cannot continue to move. The stop structure 70 limits the maximum range of movement of the mass frame 50.
[0053] The connecting beam 40 is fixedly connected to both end faces of the mass frame 50 along the first direction, and is located at the end faces away from the inner frame 30. Figure 1 As shown, the connection points between the mass frame 50 and the connecting beam 40 are located on the upper and lower end faces of the mass frame 50, and are positioned closer to and farther from the inner frame 30, allowing the connecting beam 40 to have a longer extension length. Figure 1 The connection point between the mass frame 50 and the connecting beam 40 is located near the side of the mass frame 50 in the X-axis direction.
[0054] The length of the mass frame 50 in the Y-axis direction is slightly less than the length of the inner frame 30 in the Y-axis direction. The connection point between the connecting beam 40 and the inner frame 30 is located on the two sides of the inner frame 30 in the X-axis direction, close to the upper and lower end faces of the inner frame 30.
[0055] Specifically, the movable comb teeth 501 and the fixed comb teeth 601 involved in this utility model are rectangular or trapezoidal in shape. Figure 1 , Figure 2 In the structure shown, the movable comb tooth 501 and the fixed comb tooth 601 adopt a rectangular shape, or they can be an isosceles trapezoid. The end of the movable comb tooth 501 connected to the mass frame 50 is the fixed end, and the end of the fixed comb tooth 601 connected to the fixed structure 60 is the fixed end. The fixed ends of the movable comb tooth 501 and the fixed comb tooth 601 can be the long base or the short base of the trapezoid.
[0056] The inner frame 30 is symmetrically provided with connecting beams 40, a mass frame 50, a fixed structure 60, movable comb teeth 501, and fixed comb teeth 601 on both sides along the second direction. Figure 1 As shown, the present invention symmetrically arranges identical structures on the left and right sides of the inner frame 30, with the axis of symmetry parallel to the Y-axis and passing through the midpoint of the anchor point 10. Two connecting beams 40 are fixedly connected to the left and right sides of the inner frame 30, for a total of four connecting beams 40. Two mass frames 50 are suspended and supported on the left and right sides of the inner frame 30. Each mass frame 50 has the same internal structure, and each mass frame 50 is provided with two fixed structures 60, forming two pairs of differential capacitors (C1, C2, C3, C4).
[0057] The simplified capacitance sensing structure is as follows: Figure 2 As shown, the fixed comb teeth 601 on the fixed structure 60 are divided into two parts, which, together with the movable comb teeth 501, constitute the capacitors C1 and C2, and C3 and C4 to be tested, respectively, for differential output. Using two pairs of symmetrical differential capacitors, the output signal can be amplified by one time. The actual capacitance output is:
[0058] Cout = C1 - C2 + C3 - C4.
[0059] A temperature coefficient compensation layer 201 is provided on the outer surface of the elastic beam 20. The temperature change of the Young's modulus of the temperature compensation layer 201 cancels out the temperature change of the Young's modulus of the elastic beam 20. Figure 3 As shown, a temperature coefficient compensation layer 201 can be provided on the upper surface of the elastic beam 20. Alternatively, a temperature coefficient compensation layer 201 can be provided on the lower surface of the elastic beam 20, or both the upper and lower surfaces of the elastic beam 20 can be provided. The magnitude of the change in Young's modulus temperature of the elastic beam 20 is approximately equal to, but the direction is opposite to, the change in Young's modulus temperature of the temperature coefficient compensation layer 201.
[0060] For example, if the elastic beam 20 is made of silicon, the temperature coefficient of silicon's elastic modulus is approximately -60 ppm / ℃, which directly causes temperature drift in the sensor's sensitivity. Adding a temperature coefficient compensation material, such as silicon dioxide, to the elastic beam 20 can match the temperature drift of silicon's elastic modulus, thereby reducing the sensor's sensitivity temperature drift.
[0061] Figure 3 It is along Figure 1 The cross-sectional view along the AA direction shows that the elastic beam 20, inner frame 30, and anchor point 10 are made of common semiconductor materials, such as silicon, silicon carbide, and silicon nitride. The temperature coefficient compensation layer 201 set on the elastic beam 20 is made of temperature coefficient compensation materials such as silicon dioxide, which can match the temperature drift of the elastic modulus of silicon material.
[0062] Due to the mismatch in their coefficients of thermal expansion, silicon dioxide and silicon materials can experience thermal stress deformation, affecting the sensor's output. The design of the elastic beam 20, inner frame 30, connecting beam 40, and mass frame 50 ensures that thermal stress deformation is controlled within the inner frame 30, preventing deformation of the mass frame 50 and thus avoiding the impact of thermal stress on the sensor's output.
[0063] When thermal stress causes the inner frame 30 to deform in the X direction, due to the design of the central anchor point 10, the two mass frames 50 produce small displacements in opposite directions, such as one in the +x direction and the other in the -x direction; the capacitor output Cout=C1-C2+C3-C4 can differentiate the change in capacitance and not output a signal.
[0064] When thermal stress causes the inner frame 30 to deform in the Y direction, the connecting beam 40 can release the stress in the Y direction, greatly mitigating the impact on the mass frame 50.
[0065] When thermal stress causes the inner frame 30 to deform in the Z direction, the four capacitors C1, C2, C3, and C4 all change by the same amount. The capacitor output Cout = C1 - C2 + C3 - C4 can also differentiate the change in capacitance and not output a signal.
[0066] Therefore, the mass frame 50, movable comb teeth 501, fixed comb teeth 601 and fixed structure 60 are basically unaffected by thermal stress.
[0067] This novel MEMS capacitive sensor employs differential output between the movable comb teeth 501 and the fixed comb teeth 601. This differential output can differentiate the capacitance changes caused by vibrations or accelerations on non-detected axes, preventing signal output and thus reducing the sensor's cross-axis sensitivity. By setting a temperature coefficient compensation layer 201, such as silicon dioxide, on the elastic beam 20, the temperature drift of the elastic modulus of silicon can be matched, thereby reducing the sensor's sensitivity temperature drift. Silicon dioxide and silicon can experience thermal stress deformation due to the mismatch in their coefficients of thermal expansion. Through the design of the elastic beam, inner frame, connecting beam, and mass frame, thermal stress deformation is controlled within the inner frame, preventing deformation of the mass frame and avoiding the impact of thermal stress on the sensor output.
[0068] The above description of the disclosed embodiments enables those skilled in the art to make or use the present invention. Various modifications to these embodiments will be readily apparent to those skilled in the art, and the general principles defined herein may be implemented in other embodiments without departing from the spirit or scope of the present invention. Therefore, the present invention is not to be limited to the embodiments shown herein, but is to be accorded the widest scope consistent with the principles and novel features disclosed herein.
Claims
1. A MEMS capacitive sensor, characterized in that, include: Anchor point (10), fixed setting; An elastic beam (20) extends in a straight line along a first direction, with one end fixed to an anchor point (10). An inner frame (30) surrounds the anchor point (10) and is fixedly connected to the other end of the elastic beam (20) to form a suspended structure; A connecting beam (40) extends in a straight line along the second direction, with one end fixed to the inner frame (30). The mass frame (50) is fixed to the other end of the connecting beam (40) to form a suspension. The mass frame (50) and the inner frame (30) are arranged side by side along the second direction. A set of movable comb teeth (501) are respectively provided on the two opposite side walls inside the mass frame (50). Fixed structure (60), fixedly arranged, two fixed structures (60) are relatively insulated within the area surrounded by one of the mass frames (50); each fixed structure (60) is provided with a set of fixed comb teeth (601). The first direction and the second direction are perpendicular to each other; the two sets of movable comb teeth (501) and the two sets of fixed comb teeth (601) are interleaved to form a differential capacitor.
2. The MEMS capacitive sensor according to claim 1, characterized in that, The elastic beam (20) comprises two sets, and the two sets of elastic beams (20) are located on both sides of the anchor point (10) along the first direction.
3. The MEMS capacitive sensor according to claim 2, characterized in that, Each set of elastic beams (20) comprises two straight beams or folded beams arranged side by side.
4. The MEMS capacitive sensor according to claim 1, characterized in that, A stop structure (70) is provided between the mass frame (50) and the fixed structure (60), and the stop structure (70) is provided at both ends of the fixed structure (60) along the first direction. The stop structure (70) is fixedly arranged and is used to limit the extreme position of the mass frame (50) moving along the first direction.
5. The MEMS capacitive sensor according to claim 1, characterized in that, The connecting beam (40) is fixedly connected to both ends of the mass frame (50) along the first direction and is located at the end face away from the inner frame (30).
6. The MEMS capacitive sensor according to claim 1, characterized in that, The movable comb teeth (501) and the fixed comb teeth (601) are rectangular or trapezoidal in shape.
7. The MEMS capacitive sensor according to any one of claims 1 to 6, characterized in that, The inner frame (30) is symmetrically provided with the connecting beam (40), the mass frame (50), the fixed structure (60), the movable comb teeth (501), and the fixed comb teeth (601) on both sides along the second direction.
8. The MEMS capacitive sensor according to claim 7, characterized in that, A temperature coefficient compensation layer (201) is provided on the outer surface of the elastic beam (20), and the thermal deformation amplitude of the temperature coefficient compensation layer (201) cancels out the thermal deformation amplitude of the elastic beam (20).
9. The MEMS capacitive sensor according to claim 8, characterized in that, The temperature coefficient compensation layer (201) is disposed on the upper and / or lower surface of the elastic beam (20).