A low-temperature-drift silicon resonant accelerometer structure

Abstract

The present invention discloses a low-temperature-drift silicon resonant accelerometer structure, which relates to the technical field of inertial navigation. The structure includes: an intermediate layer, an upper glass cover plate, and a lower glass cover plate; the upper glass cover plate and the lower glass cover plate are respectively covered on both sides of the outer frame of the intermediate layer and bonded thereto to vacuum-pack the intermediate layer; the support points of the resonator are designed at the geometric center of the intermediate layer of the accelerometer, and the center anchor point, the amplification lever structure and the double-ended fixed tuning fork resonator are connected through the center support beam of the resonator, and the driving detection comb teeth measure the resonant frequency affected by the inertial force, and the frequency signal is led out to the outside to characterize the acceleration magnitude; in the design of the present invention, the measurement structure of the intermediate layer is fixed to the housing with only one support point, significantly reducing the influence of thermal stress on the performance of the accelerometer. This design enables the double-ended fixed tuning fork resonator of the accelerometer to be in a nearly free thermal expansion state when the temperature changes, thereby maintaining a stable frequency response.

Description

Technical Field

[0001] The present invention relates to the technical field of inertial navigation, and in particular, to a low-temperature-drift silicon resonant accelerometer structure. Background Art

[0002] A silicon resonant accelerometer is a micromachined inertial device based on the resonance principle, which measures the change in resonance frequency to characterize acceleration. Compared with traditional capacitive accelerometers, the resonant accelerometer modulates the acceleration-sensitive signal onto the frequency of the resonator before the signal enters the circuit, ensuring that the acceleration signal is not easily affected by amplitude errors, making it easier to achieve high zero-bias stability and scale factor stability. In addition, the silicon resonant accelerometer has the advantages of small size, low cost, easy integration, and semi-digital output, and has the potential to develop towards navigation-level accuracy, with broad application prospects in the national defense and military fields.

[0003] A silicon resonant accelerometer generally consists of a sensitive mass block, a lever amplification structure, a resonator, a support mechanism, a driving mechanism, and a detection mechanism. The main principle of the resonant accelerometer is that the driving mechanism maintains the resonance of the resonator. When there is an external acceleration input, the sensitive mass block converts the acceleration into an inertial force, which is then amplified by the amplification lever and applied to the resonator. The resonator undergoes tensile or compressive changes, resulting in a change in its resonance frequency. Based on the force-frequency characteristics of the resonator, the acceleration information can be obtained by detecting the change in the resonance frequency of the resonator.

[0004] The silicon resonant accelerometer originated from the Draper experiment in the United States. The silicon resonant accelerometers currently developed in the United States are still at the world-leading level, with a zero-bias monthly stability of up to. In addition, the University of California, Berkeley in the United States designed a silicon resonant accelerometer with a two-stage amplification lever mechanism, and the scale factor can reach 160 Hz / g. Institutions such as Seoul National University in South Korea, Politecnico di Milano in Italy, and the French National Space Agency have also carried out relevant research. Universities and research institutions such as Tsinghua University, Peking University, Beijing Aerospace Control Instrument Research, and Nanjing University of Science and Technology in China have all actively carried out research on silicon resonant accelerometers and proposed various silicon resonant accelerometer structures. Although domestic and foreign silicon resonant accelerometers with various structural forms such as multi-axis, high sensitivity, and large measurement range have been developed, environmental adaptability has always been a key indicator restricting the development of silicon resonant accelerometers, and extreme temperature change conditions have further limited the practical engineering applications of silicon resonant accelerometers. The change in environmental temperature has an important impact on the performance of silicon resonant accelerometers. This is mainly due to the thermal stress generated by the thermal expansion mismatch of the support anchor points, resulting in unstable performance of the accelerometer, a decrease in the measurement accuracy of the accelerometer, performance deterioration, and limiting the engineering application of silicon resonant accelerometers to high-precision systems. Summary of the Invention

[0005] The object of the present invention is to reduce the influence of thermal stress caused by temperature changes by optimizing the structural design of the silicon resonant accelerometer, thereby improving its stability and measurement accuracy in an extreme temperature change environment.

[0006] The technical solution of the present invention is to provide a low-temperature-drift silicon resonant accelerometer structure, which includes: an intermediate layer, an upper glass cover plate, and a lower glass cover plate;

[0007] The intermediate layer includes: a mass block, a magnifying lever structure, a resonator center support beam, drive and detection comb teeth, a center anchor point, and an outer frame;

[0008] The upper glass cover plate and the lower glass cover plate are respectively covered on both sides of the outer frame of the intermediate layer and bonded thereto to vacuum-pack the intermediate layer. In addition, metal wires are arranged inside the upper glass cover plate and connected to the drive and detection comb teeth of the intermediate layer;

[0009] The center anchor point is arranged at the exact center of the intermediate layer and bonded to the upper glass cover plate. The mechanical structure of the intermediate layer is symmetrically distributed on both sides with the center anchor point as the center. One end of the drive and detection comb teeth is fixed to the center anchor point through the resonator center support beam, and the other end is bonded to the upper glass cover plate. The magnifying lever structure is connected to the other end of the resonator center support beam; when the accelerometer structure has an acceleration, the mass block applies an inertial force to the magnifying lever structure under the action of inertia. The inertial force is amplified by the magnifying lever structure, and then the resonance frequency of the drive and detection comb teeth is changed based on the force-frequency characteristic. The drive and detection comb teeth measure the resonance frequency affected by the inertial force and lead out the frequency signal to the outside through the metal wire to characterize the magnitude of the acceleration.

[0010] In any of the above technical solutions, further, the intermediate layer further includes: a doubly-clamped tuning fork resonator;

[0011] The doubly-clamped tuning fork resonator is connected to the resonator center support beam, and the thin end of the resonator center support beam is fixed on one side of the center anchor point;

[0012] Two sets of magnifying lever structures are respectively installed on both sides of the thick end of the resonator center support beam through a third beam. The second beam of the magnifying lever structure is connected to the doubly-clamped tuning fork resonator, and the first beam of the magnifying lever structure is connected to the mass block.

[0013] In any of the above technical solutions, further, the doubly-clamped tuning fork resonator includes: a first resonator cross beam, a second resonator cross beam, and two resonator side beams;

[0014] Both the first resonator cross beam and the second resonator cross beam are fixed on the resonator center support beam, and the first resonator cross beam is closer to the center anchor point; the two resonator side beams are connected to the end points of the first resonator cross beam and the second resonator cross beam to form a closed frame structure, and drive and detection comb teeth are installed at the center of the outer side of the resonator side beams.

[0015] In any of the above technical solutions, further, the part of the resonator side beam close to the first resonator cross beam has a greater stiffness, and the side close to the second resonator cross beam has a smaller stiffness.

[0016] In any of the above technical solutions, further, the drive detection comb teeth include: movable comb teeth, a first fixed comb tooth, a second fixed comb tooth, and electrodes;

[0017] The movable comb teeth are fixed on the resonator side beam, the electrodes are respectively connected to one ends of the first fixed comb tooth and the second fixed comb tooth, and both the first fixed comb tooth and the second fixed comb tooth are bonded to the upper glass cover plate through the electrodes connected thereto; the comb teeth of the movable comb teeth and the first fixed comb tooth are interlaced with each other to form a drive capacitor, and the first fixed comb tooth applies an electrostatic force on the movable comb teeth to drive them to move, thereby causing the resonator side beam to resonate; at the same time, the second fixed comb tooth and the movable comb teeth form a detection capacitor, and the change of the capacitor is detected through the second fixed comb tooth, so as to measure the resonance frequency of the resonator side beam and characterize the magnitude of the acceleration.

[0018] In any of the above technical solutions, further, the intermediate layer further includes: a mass support anchor point and a mass support beam;

[0019] The mass is connected to four mass support anchor points through four mass support beams, and the four mass support anchor points are arranged in the four frame corners of the outer frame and bonded to the upper glass cover plate.

[0020] In any of the above technical solutions, further, the mass support beam is of a U-shaped beam structure.

[0021] In any of the above technical solutions, further, the resonance frequency of the resonator side beam changes after being subjected to pressure or tension, and the resonance frequency of a single resonator side beam can be expressed as:

[0022]

[0023] In the formula, f F is the resonance frequency of the resonator side beam after being stressed, e is the Young's modulus of single crystal silicon, w is the width of the resonator side beam, L f is the length of the resonator side beam, h is the thickness of the intermediate layer, F is the tension applied to a single resonator side beam, which is negative if it is pressure, ρ is the density of single crystal silicon, and m is the mass of the movable comb teeth connected to the resonator side beam;

[0024] The above formula can be expanded by Taylor series and the high-order terms are eliminated to obtain:

[0025]

[0026] In the formula, f nis the resonant frequency of the resonator side beam when not subject to tensile or compressive stress; thus, the resonant frequency of the resonator side beam has a linear relationship with the applied force and can be used to characterize the magnitude of acceleration.

[0027] The beneficial effects of the present invention are:

[0028] In the present invention, by designing the central support beam and the central anchor point, the support points of the double-ended fixed tuning fork resonator are concentrated at the geometric center of the accelerometer, effectively reducing the influence of thermal expansion mismatch and thermal stress caused by temperature changes. This structural design enables the sensitive part (such as the resonator) to be close to the free thermal expansion state when the temperature changes, reducing the measurement error caused by temperature changes and significantly reducing the temperature drift (low temperature drift).

[0029] Due to the suppression of thermal stress by temperature changes, the present invention significantly improves the zero-bias stability and scale factor stability of the accelerometer. The accelerometer can still maintain a highly stable performance in an extreme temperature change environment and is suitable for high-precision navigation and inertial measurement systems.

[0030] By optimizing the layout of the support beam and the support anchor point, the accelerometer designed in the present invention reduces unnecessary support points, making the overall structure more concise. After the structure is simplified, the processing technology requirements are reduced, thereby reducing the common-mode error introduced by inaccurate processing and further improving the stability and performance of the accelerometer. BRIEF DESCRIPTION OF THE DRAWINGS

[0031] The above and additional advantages of the present invention will become apparent and easy to understand in conjunction with the following description of the embodiments with reference to the accompanying drawings, wherein:

[0032] Figure 1 is a schematic diagram of the intermediate layer structure of a low-temperature drift silicon resonant accelerometer structure according to an embodiment of the present invention;

[0033] Figure 2 is a schematic diagram of the lever amplification structure of a low-temperature drift silicon resonant accelerometer structure according to an embodiment of the present invention;

[0034] Figure 3 is a schematic diagram of the double-ended fixed tuning fork resonator structure of a low-temperature drift silicon resonant accelerometer structure according to an embodiment of the present invention;

[0035] Figure 4 is a schematic diagram of the resonator central beam support structure of a low-temperature drift silicon resonant accelerometer structure according to an embodiment of the present invention;

[0036] Figure 5 is a schematic diagram of the drive and detection comb structure of a low-temperature drift silicon resonant accelerometer structure according to an embodiment of the present invention;

[0037] Figure 6 Schematic diagram of the mass support beam structure of a low-temperature drift silicon resonant accelerometer structure according to an embodiment of the present invention;

[0038] Figure 7 It is a simulation result diagram of the frequency and acceleration of a silicon resonant accelerometer of a low-temperature drift silicon resonant accelerometer structure according to an embodiment of the present invention.

[0039] Wherein, 1 - mass, 2 - amplification lever structure, 3 - double-ended fixed tuning fork resonator, 4 - resonator center support beam, 5 - drive and detection comb teeth, 6 - center anchor point, 7 - mass support anchor point, 8 - mass support beam, 9 - outer frame, 10 - first beam, 11 - second beam, 12 - third beam, 13 - first resonator cross beam, 14 - second resonator cross beam, 15 - resonator side beam, 16 - thin end, 17 - thick end, 18 - movable comb teeth, 19 - first fixed comb teeth, 20 - second fixed comb teeth, 21 - electrode. Specific embodiments

[0040] In order to more clearly understand the above-mentioned objects, features and advantages of the present invention, the present invention will be further described in detail below with reference to the accompanying drawings and specific embodiments. It should be noted that, without conflict, the embodiments of the present invention and the features in the embodiments may be combined with each other.

[0041] In the following description, many specific details are set forth in order to fully understand the present invention. However, the present invention may also be implemented in other ways different from those described herein. Therefore, the protection scope of the present invention is not limited by the specific embodiments disclosed below.

[0042] As Figure 1 shown, this embodiment provides a low-temperature drift silicon resonant accelerometer structure, including: an intermediate layer, an upper glass cover plate and a lower glass cover plate.

[0043] The upper glass cover plate and the lower glass cover plate are respectively covered on both sides of the outer frame of the intermediate layer and bonded thereto to vacuum-pack the intermediate layer. In addition, metal wires are arranged inside the upper glass cover plate and connected to the electrodes of the drive and detection comb teeth 5 of the intermediate layer for leading out frequency signals to the outside.

[0044] The intermediate layer specifically includes: a mass 1, an amplification lever structure 2, a double-ended fixed tuning fork resonator 3, a resonator center support beam 4, drive and detection comb teeth 5, a center anchor point 6, a mass support anchor point 7, a mass support beam 8, and an outer frame 9.

[0045] The mass block 1 is made of single crystal silicon and fabricated by bulk silicon processing technology. The mass block 1 is connected to four mass block support anchors 7 through four mass block support beams 8. The four mass block support anchors 7 are arranged within the four frame corners of the outer frame 9 and are bonded to the upper glass cover plate.

[0046] The central anchor 6 is arranged at the exact center of the middle layer and is bonded to the upper glass cover plate. The mechanical structure of the middle layer is symmetrically distributed on both sides centered around the central anchor 6. Only the distribution on one side is described below, and the symmetry on the other side will not be elaborated further.

[0047] As Figures 2 to 4 shown, the double-ended fixed tuning fork resonator 3 is connected to the resonator central support beam 4. The thin end 16 of the resonator central support beam 4 is fixed to one side of the central anchor 6.

[0048] Two groups of amplification lever structures 2 are respectively installed on both sides of the thick end 17 of the resonator central support beam 4 through the third beam 12. The second beam 11 of the amplification lever structure 2 is connected to the double-ended fixed tuning fork resonator 3, and the first beam 10 of the amplification lever structure 2 is connected to the mass block 1.

[0049] Specifically, the double-ended fixed tuning fork resonator 3 includes a first resonator cross beam 13, a second resonator cross beam 14, and two resonator side beams 15. Both the first resonator cross beam 13 and the second resonator cross beam 14 are fixed to the resonator central support beam 4, and the first resonator cross beam 13 is closer to the central anchor 6. The two resonator side beams 15 are connected to the endpoints of the first resonator cross beam 13 and the second resonator cross beam 14 to form a closed frame structure, and the drive detection comb teeth 5 are installed at the center of the outer side of the resonator side beam 15.

[0050] Particularly, the part of the resonator side beam 15 close to the first resonator cross beam 13 has a greater stiffness to ensure the stability of the connection, and the side close to the second resonator cross beam 14 has a smaller stiffness to facilitate increasing the amplification factor when the amplification lever structure 2 transmits pressure.

[0051] As Figure 5 shown, the drive detection comb teeth 5 include: movable comb teeth 18, first fixed comb teeth 19, second fixed comb teeth 20, and electrodes 21.

[0052] The movable comb teeth 18 are fixed on the resonator side beam 15. The electrodes 21 are respectively connected to one ends of the first fixed comb teeth 19 and the second fixed comb teeth 20. Both the first fixed comb teeth 19 and the second fixed comb teeth 20 are bonded to the upper glass cover plate through the electrodes 20 connected thereto respectively; the comb teeth of the movable comb teeth 18 and the first fixed comb teeth 19 are interlaced with each other to form a driving capacitor. The first fixed comb teeth 19 apply an electrostatic force on the movable comb teeth 18 to drive them to move, thereby causing the resonator side beam 15 to resonate; at the same time, the second fixed comb teeth 19 and the movable comb teeth 18 form a detection capacitor, and the change of the capacitor is detected through the second fixed comb teeth 20, so as to measure the resonance frequency of the resonator side beam 15. The electrodes 21 lead out the frequency signal to the outside through the metal wires of the upper glass cover plate connected thereto, characterizing the magnitude of the acceleration.

[0053] As Figure 6 shown, in order to eliminate the thermal stress of the mass support anchor 7 along the X sensitive axis direction, the mass support beam 8 is designed as a U-shaped beam structure to reduce its stiffness along the X direction, and at the same time ensure its stiffness in the Y direction to avoid generating cross-coupling errors.

[0054] When the accelerometer senses the acceleration in the external X direction, the mass support beam 8 plays a role of supporting and buffering for the mass. The mass 1 applies an inertial force to the first beam 10 of the amplification lever structure 2 under the action of inertia. The inertial force is sequentially transmitted to the resonator side beam 15 through the amplification lever structure 2 and the double-ended fixed tuning fork resonator 3. The driving and detecting comb teeth 5 installed on the resonator side beam 15 detect the vibration change of the resonator side beam 15 to calculate the acceleration received by the low-temperature drift silicon resonant accelerometer structure.

[0055] Specifically, after the resonator side beam 15 is subjected to pressure or tension, the resonance frequency changes. The resonance frequency of a single resonator side beam 15 can be expressed as:

[0056]

[0057] In the formula, f F is the resonance frequency of the resonator side beam 15 after being stressed, E is the Young's modulus of single-crystal silicon, w is the width of the resonator side beam 15, L f is the length of the resonator side beam 15, h is the thickness of the intermediate layer, F is the tension received by a single resonator side beam 15, which is negative if it is pressure, ρ is the density of single-crystal silicon, and m is the mass of the movable comb teeth 18 connected to the resonator side beam 15.

[0058] The above formula can be expanded by Taylor series and the high-order terms are eliminated to obtain:

[0059]

[0060] In the formula, f nis the resonance frequency of the resonator side beam 15 when not subjected to tensile or compressive stress. Therefore, the resonance frequency of the resonator side beam 15 has a linear relationship with the applied force, and thus can be used to characterize the magnitude of acceleration. The results of the structural simulation using COMSOL software are as shown in Figure 7 shown. The input acceleration has a linear relationship with the resonance frequency of a single resonance beam. Thermal stress simulation at a high temperature of 70 °C was also carried out. The simulation results show that the thermal stress of the resonator side beam 15 is very small, with a maximum of only 0.02 MPa, and its influence on the resonance frequency of the resonator side beam 15 can be basically ignored.

[0061] In summary, the present invention proposes a low-temperature-drift silicon resonant accelerometer structure, including: an intermediate layer, an upper glass cover plate, and a lower glass cover plate.

[0062] The intermediate layer includes: a mass block 1, an amplification lever structure 2, a resonator center support beam 4, driving and detecting comb teeth 5, a center anchor 6, and an outer frame 9.

[0063] The upper glass cover plate and the lower glass cover plate are respectively covered on both sides of the outer frame of the intermediate layer and bonded thereto, so that the intermediate layer is vacuum encapsulated. In addition, metal wires are arranged inside the upper glass cover plate and connected to the driving and detecting comb teeth 5 of the intermediate layer.

[0064] The center anchor 6 is arranged at the center of the intermediate layer and bonded to the upper glass cover plate. The mechanical structure of the intermediate layer is symmetrically distributed on both sides with the center anchor 6 as the center. One end of the driving and detecting comb teeth 5 is fixed to the center anchor 6 through the resonator center support beam 4, and the other end is bonded to the upper glass cover plate. The amplification lever structure 2 is connected to the other end of the resonator center support beam 4. When the accelerometer structure has an acceleration, the mass block 1 applies an inertial force to the amplification lever structure 2 under the action of inertia. The inertial force is amplified by the amplification lever structure 2, and then based on the force-frequency characteristic, the resonance frequency of the driving and detecting comb teeth 5 is changed. The driving and detecting comb teeth 5 measure the resonance frequency affected by the inertial force and lead out the frequency signal to the outside through the metal wire to characterize the magnitude of the acceleration.

[0065] In the present invention, terms such as "mounted", "connected", "joined", "fixed", etc. should be understood in a broad sense. For example, "connected" can be a fixed connection, a detachable connection, or an integral connection; "joined" can be a direct connection or an indirect connection through an intermediate medium. For those of ordinary skill in the art, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0066] The shapes of the various components in the drawings are all schematic, and there is no exclusion of a certain difference from their actual shapes. The drawings are only used to illustrate the principle of the present invention and are not intended to limit the present invention.

[0067] Although the present invention has been disclosed in detail with reference to the accompanying drawings, it should be understood that these descriptions are merely exemplary and are not intended to limit the application of the present invention. The scope of protection of the present invention is defined by the appended claims and may include various modifications, adaptations, and equivalent schemes made to the invention without departing from the scope and spirit of the present invention.

Claims

1. A low-temperature-drift silicon resonant accelerometer structure, characterized in that The structure includes: an intermediate layer, an upper glass cover plate, and a lower glass cover plate; The intermediate layer includes: a mass block (1), a magnifying lever structure (2), a double-ended fixed tuning fork resonator (3), a resonator center support beam (4), driving and detecting comb teeth (5), a center anchor point (6), and an outer frame (9); The upper glass cover plate and the lower glass cover plate are respectively covered on both sides of the outer frame of the intermediate layer and bonded thereto, so that the intermediate layer is vacuum encapsulated. In addition, metal wires are arranged inside the upper glass cover plate and connected to the driving and detecting comb teeth (5) of the intermediate layer; The center anchor point (6) is arranged at the exact center of the intermediate layer and bonded to the upper glass cover plate. The mechanical structure of the intermediate layer is symmetrically distributed on both sides with the center anchor point (6) as the center. The driving and detecting comb teeth (5) are installed at the center of the outer side of the resonator side beam (15). One end of the driving and detecting comb teeth (5) is fixed to the center anchor point (6) through the resonator center support beam (4) connected by the resonator side beam (15), and the other end is bonded to the upper glass cover plate. The magnifying lever structure (2) is connected to the other end of the resonator center support beam (4); the double-ended fixed tuning fork resonator (3) is connected to the resonator center support beam (4). The thin end (16) of the resonator center support beam (4) is fixed to one side of the center anchor point (6). Two sets of magnifying lever structures (2) are respectively installed on both sides of the thick end (17) of the resonator center support beam (4) through the third beam (12); the double-ended fixed tuning fork resonator (3) includes: a first resonator cross beam (13), a second resonator cross beam (14), and two resonator side beams (15); Both the first resonator cross beam (13) and the second resonator cross beam (14) are fixed to the resonator center support beam (4), and the first resonator cross beam (13) is closer to the center anchor point (6); the two resonator side beams (15) are connected to the endpoints of the first resonator cross beam (13) and the second resonator cross beam (14) to form a closed frame structure; When the accelerometer structure has an acceleration, the mass block (1) applies an inertial force to the magnifying lever structure (2) under the action of inertia. The inertial force is amplified by the magnifying lever structure (2), and then based on the force-frequency characteristic, the resonance frequency of the driving and detecting comb teeth (5) is changed. The driving and detecting comb teeth (5) measure the resonance frequency affected by the inertial force and lead out a frequency signal to the outside through the metal wire, characterizing the magnitude of the acceleration.

2. The low-temperature drift silicon resonant accelerometer structure according to claim 1, wherein, The second beam (11) of the magnifying lever structure (2) is connected to the double-ended fixed tuning fork resonator (3), and the first beam (10) of the magnifying lever structure (2) is connected to the mass block (1).

3. The low-temperature drift silicon resonant accelerometer structure according to claim 1, characterized in that The part of the resonator side beam (15) close to the first resonator cross beam (13) has a greater stiffness, and the side close to the second resonator cross beam (14) has a smaller stiffness.

4. The low-temperature drift silicon resonant accelerometer structure according to claim 3, characterized in that, The driving and detecting comb teeth (5) include: movable comb teeth (18), a first fixed comb tooth (19), a second fixed comb tooth (20), and an electrode (21); The movable comb teeth (18) are fixed on the resonator side beams (15). The electrodes (21) are respectively connected to one ends of the first fixed comb teeth (19) and the second fixed comb teeth (20). Both the first fixed comb teeth (19) and the second fixed comb teeth (20) are bonded to the upper glass cover plate through the electrodes (21) connected thereto. The comb teeth of the movable comb teeth (18) and the first fixed comb teeth (19) are interlaced with each other to form a driving capacitor. The first fixed comb teeth (19) apply an electrostatic force on the movable comb teeth (18) to drive their movement, thereby causing the resonator side beams (15) to resonate. At the same time, the second fixed comb teeth (20) and the movable comb teeth (18) form a detection capacitor. The change of the capacitor is detected through the second fixed comb teeth (20), so as to measure the resonance frequency of the resonator side beams (15) and characterize the magnitude of the acceleration.

5. The low-temperature drift silicon resonant accelerometer structure according to claim 1, characterized in that The intermediate layer further includes: a mass support anchor point (7) and a mass support beam (8); The mass (1) is connected to four mass support anchor points (7) through four mass support beams (8). The four mass support anchor points (7) are arranged at the four frame corners of the outer frame (9) and are bonded to the upper glass cover plate.

6. The low-temperature drift silicon resonant accelerometer structure according to claim 5, wherein, The mass support beam (8) is of a U-shaped beam structure.

7. The low-temperature drift silicon resonant accelerometer structure according to claim 4, wherein When the resonator side beam (15) is subjected to pressure or tension, its resonance frequency changes. The resonance frequency of a single resonator side beam (15) can be expressed as: where f F is the resonant frequency of the resonator side beam (15) after being stressed, E is the Young's modulus of single crystal silicon, w is the width of the resonator side beam (15), L f is the length of the resonator side beam (15), h is the thickness of the intermediate layer, F is the tensile force applied to a single resonator side beam (15), which is negative if it is a compressive force, ρ is the density of single crystal silicon, and m is the mass of the movable comb teeth (18) connected to the resonator side beam (15); The above formula can be expanded by Taylor series and the high-order terms can be eliminated to obtain: where f n is the resonance frequency of the resonator side beam (15) when not subject to tensile or compressive stress; thus, the resonance frequency of the resonator side beam (15) has a linear relationship with the applied force and can thus be used to characterize the magnitude of acceleration.

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