Resonance differential pressure sensor with low temperature drift characteristic based on double-resonator structure
Through the dual resonator structural design and static pressure balance, the static pressure error and temperature drift problems of resonant differential pressure sensor in a changing static pressure environment are solved, and high-precision small differential pressure measurement is achieved, which is suitable for aerospace and deep-sea exploration and other fields.
Patent Information
- Application Number
- CN202510605066.1
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2025-05-12
- Publication Date
- 2025-07-25
AI Technical Summary
Under changing static pressure environments, the existing resonant differential pressure sensors have static pressure errors and temperature drift problems, making it difficult to achieve high-precision measurement of small differential pressures.
A resonant differential pressure sensor based on a dual resonator structure is adopted, and the reverse frequency characteristics of the compressive stress resonator and tensile stress resonator are designed, combined with the static pressure balance structure, temperature compensation and static pressure elimination are achieved, and a multi-layer structure is manufactured using micro-machining technology.
It significantly reduces static pressure error and temperature drift, improves the stability and applicability of the sensor, and can achieve high-precision small differential pressure measurement in a wide temperature zone, and is suitable for rigorous scenarios such as aerospace and deep-sea exploration.
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Figure CN120369187A_ABST
Abstract
Description
Technical Field
[0001] The present invention relates to the technical field of microelectromechanical systems (MEMS), and in particular to a resonant differential pressure sensor with low temperature drift characteristics based on a dual resonator structure, which is suitable for measuring tiny differential pressures in a varying static pressure environment. Background Art
[0002] With the development of microelectromechanical systems (MEMS) technology, resonant pressure sensors have received extensive attention in the field of pressure measurement due to their high precision, high sensitivity, and stability. MEMS pressure sensors can be divided into differential pressure, absolute pressure, and gauge pressure types, among which differential pressure sensors have important applications in fields such as aerospace, petrochemical industry, and environmental monitoring. However, in a varying static pressure environment (such as in deep sea exploration or aerospace applications), the precise measurement of tiny differential pressures faces major challenges, and static pressure errors and temperature drift have become the main factors limiting measurement accuracy.
[0003] In the prior art, resonant differential pressure sensors detect pressure through changes in resonant frequency, but their static pressure errors and temperature sensitivities still make it difficult to meet the requirements of extreme environments. For example, although some research institutions and companies at home and abroad (such as Druck, YOKOGAWA, Paroscientific, etc.) have developed resonant sensors with certain improvements in accuracy, in a varying static pressure environment, the static pressure errors are still significant, and the problem of temperature drift has not been completely solved. Domestic research institutions such as the Institute of Electronics, Chinese Academy of Sciences, and Beihang University have made certain progress in the field of MEMS differential pressure sensors, but further optimization of the design is still needed to improve differential pressure sensitivity and reduce errors.
[0004] Therefore, there is an urgent need to design a differential pressure sensor that can achieve high-precision measurement of tiny differential pressures in a varying static pressure environment and effectively offset the effects of static pressure and temperature at the same time. Summary of the Invention
[0005] The purpose of the present invention is to provide a resonant differential pressure sensor with low temperature drift characteristics based on a dual resonator structure. Through the dual resonator design and static pressure balance structure, high-precision measurement of tiny differential pressures is achieved, and static pressure errors and temperature drift are significantly reduced, improving the stability and applicability of the sensor.
[0006] To achieve the above-mentioned invention purpose, the present invention provides the following technical solutions.
[0007] A resonant differential pressure sensor with low temperature drift characteristics based on a dual resonator structure, comprising a glass base, a static pressure sensitive pressure sensing layer, a dual resonator layer, a silicon island layer, and a static differential sensitive pressure sensing layer stacked from bottom to top; a static differential sensitive upper pressure sensing film exposed to the working environment is formed on the upper surface of the static differential sensitive pressure sensing layer.
[0008] The static error-sensitive upper pressure-sensing film and the static error-sensitive pressure-sensing layer are respectively located on the upper side of the silicon island layer;
[0009] The static error-sensitive pressure-sensing layer is used to sense the differential pressure change, and the static pressure-sensitive pressure-sensing layer is used to balance the static pressure. The two transfer stress through the silicon island layer;
[0010] The silicon island layer includes a static error-sensitive upper main island on the upper surface, a static error-sensitive lower main island on the lower surface, and a differential pressure-sensitive sub-island connecting the two. A movable structure groove is provided on the periphery of the differential pressure-sensitive sub-island; an electrode hole is also provided on the silicon island layer, and the electrode hole is used to connect an external circuit;
[0011] The double resonator layer includes a symmetrically arranged compressive stress resonator, a tensile stress resonator, a driving electrode, a grounding electrode, and a detection electrode. The compressive stress resonator and the tensile stress resonator are respectively connected to the differential pressure-sensitive sub-island, and the differential pressure-sensitive sub-island transfers the stress to the compressive stress resonator and the tensile stress resonator; the driving electrode and the grounding electrode form a conduction circuit, and the detection electrode is used to collect the frequency output signals of the compressive stress resonator and the tensile stress resonator and convert them into square wave signals;
[0012] A glass base ventilation hole is provided on the glass base, and the glass base is communicated with the static pressure-sensitive pressure-sensing layer through the glass base ventilation hole to balance the static pressure.
[0013] Further, the glass base, the static pressure-sensitive pressure-sensing layer, the double resonator layer, the silicon island layer, and the static error-sensitive pressure-sensing layer can be fixedly connected by a bonding technique.
[0014] Further, the static pressure-sensitive pressure-sensing layer includes a static pressure-sensitive lower pressure-sensing film and a static pressure-sensitive pressure-sensing layer movable groove. The static pressure-sensitive lower pressure-sensing film is communicated with the glass base ventilation hole and is used to sense the external static pressure; the static pressure-sensitive pressure-sensing layer movable groove provides an elastic deformation space for stress transfer.
[0015] Further, a tensile stress resonator cover plate and a compressive stress resonator cover plate are also provided on the double resonator layer. The tensile stress resonator cover plate and the compressive stress resonator cover plate are used to protect the resonator and transfer the differential pressure stress.
[0016] Further, the frequency changes of the compressive stress resonator and the tensile stress resonator are opposite at different temperatures. The frequency of the compressive stress resonator decreases with the increase of pressure, and the frequency of the tensile stress resonator increases with the increase of pressure. And the absolute values of the slopes of the frequency changes of the two are equal and opposite in magnitude, and the temperature influence is cancelled by summation.
[0017] Further, when the pressure on the side where the static error-sensitive pressure-sensing layer is located is greater than the pressure on the side where the static pressure-sensitive pressure-sensing layer is located, the static error-sensitive upper main island and the static error-sensitive lower main island move downward, and the differential pressure-sensitive sub-island deflects, transferring the stress to the compressive stress resonator and the tensile stress resonator, triggering them to enter the working mode.
[0018] Furthermore, a mass block of the double resonator layer is provided on the double resonator layer. The mass block of the double resonator layer is bonded to the static pressure sensitive pressure sensing layer to transfer the stress caused by the static pressure. When the pressure sensing film under the static pressure sensitivity deforms, the stress is transferred to the main island under the static difference sensitivity through the mass block of the double resonator layer. When the pressure sensing film on the static difference sensitivity deforms, the stress is transferred to the main island on the static difference sensitivity. When the deformation amount of the pressure sensing film on the static difference sensitivity is the same as the deformation amount of the pressure sensing film under the static pressure sensitivity due to the static pressure, static pressure balance is achieved.
[0019] Furthermore, a 5V voltage is applied to the drive electrode, which forms a circuit with the ground electrode to collect the frequency signals of the compressive stress resonator and the tensile stress resonator.
[0020] Furthermore, the pressure sensing film on the static difference sensitivity and the pressure sensing film under the static pressure sensitivity are made of highly elastic single-crystalline silicon material to improve the response speed and sensitivity to pressure changes.
[0021] The working principle of the present invention is as follows:
[0022] The pressure sensing film on the static difference sensitivity is exposed to the working condition environment, and the pressure sensing film under the static pressure sensitivity communicates with the outside through the vent hole of the glass base to balance the static pressure. When the pressure on the side where the pressure sensing film on the static difference sensitivity is located is greater than that on the side where the pressure sensing film under the static pressure sensitivity is located, the main island on the static difference sensitivity and the main island under the static difference sensitivity are simultaneously pressed down, and the differential pressure sensitive sub-island deflects, transferring the stress to the compressive stress resonator and the tensile stress resonator, triggering them to enter the working mode and generating a frequency output signal. A 5V voltage is applied to the drive electrode, which forms a circuit with the ground electrode to convert the frequency signal into a square wave signal for acquisition.
[0023] The temperature compensation mechanism of the present invention is as follows:
[0024] The frequency changes of the compressive stress resonator and the tensile stress resonator show opposite trends at different temperatures. The frequency of the compressive stress resonator decreases with the increase of pressure, and the frequency of the tensile stress resonator increases with the increase of pressure. Moreover, the absolute values of the slopes of the frequency changes of the two are equal and opposite in magnitude. By summing, the temperature influence is cancelled out to achieve temperature compensation.
[0025] The static pressure compensation mechanism of the present invention is as follows:
[0026] When the static pressures on both sides are the same, the main island on the static difference sensitivity and the main island under the static difference sensitivity are in a balanced state, and the static pressures they receive are equal in magnitude and opposite in direction. The differential pressure sensitive sub-island has no net moment acting on it and does not deflect, thus eliminating the static pressure error.
[0027] Compared with the prior art, the present invention has the following advantages:
[0028] 1. The present invention achieves intrinsic cancellation of temperature drift from the mechanical structure level through the reverse frequency characteristic design of the compressive stress resonator and the tensile stress resonator (the absolute value of the frequency change slope is equal and the sign is opposite), without relying on additional temperature sensors or complex algorithms. In the wide temperature range of -40℃ to 80℃, the temperature sensitivity is as low as 0.365Hz / ℃, which is significantly better than the solution relying on circuit compensation in the prior art, effectively canceling out temperature drift and making the sensor suitable for operation in a wide temperature range.
[0029] 2. The present invention adopts a symmetrically arranged static differential sensitive upper main island, lower main island and upper and lower pressure-sensitive membrane structure, and realizes real-time static pressure balance through the vent holes of the glass base. When the static pressure on both sides is consistent, the differential pressure sensitive secondary island maintains mechanical balance, completely eliminates the interference of static pressure on the resonator, and reduces the static pressure error. The static pressure error approaches zero within the static pressure range of 15MPa, solving the problem of significant error in the variable static pressure environment in the prior art.
[0030] 3. The sensor has high differential pressure sensitivity and can accurately measure tiny differential pressure changes. Through the elastic coupling design of the differential pressure sensitive sub-island and the dual resonator, the tiny differential pressure is converted into the frequency difference change of the resonator. The differential pressure sensitivity reaches above 26Hz / kPa, and the linearity is better than 99.9%. It can accurately capture the subtle changes of differential pressure signals in the range of 0-300kPa, meeting the needs of micro differential pressure measurement in harsh scenarios such as aerospace, deep-sea exploration, etc., and is suitable for high-precision measurement scenarios in changing static pressure environments.
[0031] 4. Micro-machining technology is used to achieve multi-layer structure bonding, making the sensor compact and cost-controlled. The core components (such as pressure-sensitive film and resonator) are prepared by high-precision photolithography and corrosion processes, with high stability, overcoming the defects of traditional resonant sensors with complex structures and high costs, and are suitable for industrial production and application. BRIEF DESCRIPTION OF THE DRAWINGS
[0032] Figure 1 Schematic diagram of the overall structure of the sensor.
[0033] Figure 2 Exploded view of the sensor hierarchy.
[0034] Figure 3 It is a front view schematic diagram of the static difference sensitive pressure sensing layer.
[0035] Figure 4 This is a schematic front view of the silicon island layer.
[0036] Figure 5 Schematic diagram of the back view of the silicon island layer.
[0037] Figure 6 Schematic diagram of the front view of the dual resonator layer.
[0038] Figure 7 Front view schematic diagram of the static pressure sensitive pressure sensing layer.
[0039] Figure 8 Back view schematic diagram of the static pressure sensitive pressure sensing layer.
[0040] Figure 9 Front view schematic diagram of the glass base.
[0041] Figure 10 Front view schematic diagram of the working mode of the double resonator layer.
[0042] Figure 11 Static pressure error curve within the range of static pressure of 15 MPa.
[0043] Figure 12 Differential pressure sensitivity curve within the range of differential pressure of 0 - 300 kPa.
[0044] Figure 13 Temperature sensitivity curve under no-load condition.
[0045] Each mark in the figure is as follows: 1 electrode hole; 2 static-differential sensitive upper pressure sensing film; 3 static-differential sensitive pressure sensing layer; 4 silicon island layer; 5 double resonator layer; 6 static pressure sensitive pressure sensing layer; 7 glass base; 8 static-differential sensitive upper main island; 9 static-differential sensitive lower main island; 10 differential pressure sensitive sub-island; 11 movable structure groove; 12 drive electrode; 13 compressive stress resonator; 14 tensile stress resonator; 15 ground electrode; 16 double resonator layer mass block; 17 tensile stress resonator cover plate; 18 compressive stress resonator cover plate; 19 detection electrode; 20 static pressure sensitive lower pressure sensing film; 21 movable groove of the static pressure sensitive pressure sensing layer; 22 air vent hole of the glass base. Specific embodiments
[0046] In order to make the objectives, technical solutions and advantages of the present invention clearer and more understandable, the following embodiments will further explain the present invention in conjunction with the accompanying drawings. It should be understood that the specific embodiments described herein are only used to explain the present invention and are not used to limit the present invention.
[0047] See Figures 1 - 9 , the sensor embodiment of the present invention includes an electrode hole (1), a static-differential sensitive upper pressure sensing film (2), a static-differential sensitive pressure sensing layer (3), a silicon island layer (4), a double resonator layer (5), a static pressure sensitive pressure sensing layer (6), a glass base (7), a static-differential sensitive upper main island (8), a static-differential sensitive lower main island (9), a differential pressure sensitive sub-island (10), a movable structure groove (11), a drive electrode (12), a compressive stress resonator (13), a tensile stress resonator (14), a ground electrode (15), a double resonator layer mass block (16), a tensile stress resonator cover plate (17), a compressive stress resonator cover plate (18), a static pressure sensitive lower pressure sensing film (20), and an air vent hole (22) of the glass base.
[0048] The sensors are hierarchically arranged from bottom to top as a glass base (7), a static pressure sensitive pressure sensing layer (6), a dual resonator layer (5), a silicon island layer (4), a static error sensitive upper pressure sensing layer (3), and a static error sensitive upper pressure sensing film (2). The static error sensitive upper pressure sensing film (2) is made of single crystal silicon with a thickness of 35 microns and is formed by microfabrication technology. One side of it is completely exposed to the working environment to sense pressure changes. The static error sensitive upper pressure sensing layer (3) communicates with the outside through the ventilation holes (22) of the glass base, and includes a static pressure sensitive lower pressure sensing film (20) with a thickness of 35 microns, which is bonded to the mass block (16) of the dual resonator layer for stress transfer. The silicon island layer (4) includes a static error sensitive upper main island (8), a static error sensitive lower main island (9), and a differential pressure sensitive sub - island (10), and is formed by wet etching technology to ensure the mechanical stability of the structure. The dual resonator layer (5) includes a compressive stress resonator (13), a tensile stress resonator (14), a drive electrode (12), a ground electrode (15), a tensile stress resonator cover plate (17), and a compressive stress resonator cover plate (18), and is processed by MEMS technology to generate a frequency output signal. The static pressure sensitive pressure sensing layer (6) includes a movable structure groove (11) to provide space for the vibration of the resonator. The glass base (7) can be bonded to the static pressure sensitive pressure sensing layer (6) by high - temperature bonding technology, and the ventilation holes (22) of the glass base ensure the pressure balance on the side where the static pressure sensitive pressure sensing layer is located.
[0049] The static error sensitive pressure sensing layer (3): It is made of single crystal silicon with a thickness of 500 microns. A static error sensitive upper pressure sensing film (2) with a thickness of 35 microns is formed on one side of it. The size and shape of this film are precisely controlled by microfabrication technology to improve the sensitivity to pressure changes.
[0050] The silicon island layer (4): It is located above the static error sensitive upper pressure sensing layer (3) and is tightly bonded to the upper pressure sensing layer by direct bonding technology. This layer includes multiple island - like structures, and each island - like structure is formed by wet etching technology to ensure the stability of the structure.
[0051] The dual resonator layer (5): It is located above the silicon island layer (4). This structure is precisely processed by micro - electro - mechanical system (MEMS) technology to achieve precise control of the resonant frequency. The compressive stress resonator (13) and the tensile stress resonator (14) of the dual resonator layer (5) are formed by microfabrication technology. They are mechanically coupled through a specific design to facilitate predictable changes in the resonant frequency when subjected to pressure changes. When the static error sensitive upper pressure sensing layer (3) senses external pressure changes, the pressure is transmitted through the static error sensitive upper pressure sensing film (2) to the silicon island layer (4), and further transmitted to the dual resonator layer (5).
[0052] Static pressure sensitive pressure sensing layer (6): Located below the double resonator layer (5), it is tightly bonded to the resonator layer through silicon-silicon bonding technology. The static pressure sensitive pressure sensing layer (6) includes a static pressure sensitive lower pressure sensing film (20), whose shape and thickness match those of the static differential sensitive upper pressure sensing film (2) to achieve balanced transmission of pressure.
[0053] The implementation method of the sensor manufacturing process is as follows. Interlayer bonding: The static differential sensitive upper pressure sensing layer (3), silicon island layer (4), double resonator layer (5) and static pressure sensitive pressure sensing layer (6) are tightly bonded through high-temperature bonding technology to ensure the integrity and stability of the sensor. Electrode hole (1) fabrication: Electrode holes are formed on the silicon island layer (4) through wet etching technology for connecting to external circuits. Electrode connection: The drive electrode (12), ground electrode (15) and detection electrode (19) of the double resonator layer (5) are connected to the external circuit through micro-welding technology to ensure accurate signal transmission.
[0054] When the sensor is in a changing static pressure environment, the static differential sensitive upper pressure sensing layer (3) and the static pressure sensitive pressure sensing layer (6) respectively sense the pressure change, and convert the pressure change into stress change through the static differential sensitive upper pressure sensing film (2) and the static pressure sensitive lower pressure sensing film (20). The stress change is balanced by the static differential sensitive upper main island (8) and the static differential sensitive lower main island (9) of the silicon island layer (4) for the stress change transmitted by the static pressure, and the differential pressure sensitive sub-island (10) transmits the differential pressure stress change to the tensile stress resonator cover plate (17) and the compressive stress resonator cover plate (18) and drives them to rotate, thereby transmitting the differential pressure stress to the compressive stress resonator (13) and the tensile stress resonator (14), and the two generate corresponding vibrations according to the stress change. The detection electrode (19) outputs corresponding electrical signals according to the vibration frequency changes of the compressive stress resonator (13) and the tensile stress resonator (14), and the signals are processed through an external circuit to finally obtain the differential pressure value.
[0055] See Figures 10 - 13 , to verify the performance of the low-error differential pressure sensor under changing static pressure based on the double resonator structure described in the present invention, multiple rounds of simulation analysis are carried out, focusing on evaluating key performance indicators such as the working mode of the double resonator, static pressure error, and differential pressure sensitivity. The following are the specific verification results:
[0056] Verification of the working mode of the double resonator:
[0057] See Figure 10, the front view of the working mode of the dual resonator layer (5) shows the vibration state of the compressive stress resonator (13) and the tensile stress resonator (14). In the experiment, a 5V voltage was applied by the driving electrode (12) to excite the compressive stress resonator (13) and the tensile stress resonator (14) into the working mode. Among them, Figure a shows the displacement size distribution of the compressive stress resonator and the tensile stress resonator at the characteristic frequency of 35063 Hz. Figure b shows the displacement size distribution of the compressive stress resonator and the tensile stress resonator at the characteristic frequency of 36294 Hz. The test results show that when the pressure on the side where the static differential sensitive upper pressure-sensitive film (2) is located is greater than the side where the static pressure sensitive lower pressure-sensitive film (20) is located, the differential pressure sensitive sub-island (10) deflects and transfers the stress to the dual resonator layer (5). The compressive stress resonator (13) is subjected to compressive stress, and its resonant frequency decreases; the tensile stress resonator (14) is subjected to tensile stress, and its resonant frequency increases. The absolute values of the slopes of the two frequency changes are equal and opposite in magnitude, verifying the effectiveness of the dual resonator design in temperature compensation. In addition, the vibration amplitude of the dual resonator under the action of differential pressure is stable, showing good mechanical coupling characteristics, ensuring high-sensitivity detection of small differential pressures.
[0058] Static pressure error verification:
[0059] See also Figure 11 , showing the static pressure error curve within the static pressure range of 15MPa. The experiment was conducted within the static pressure range of 0-15MPa to simulate the sensor performance under a variable static pressure environment. The test results show that when the static pressure on both sides is consistent, the static differential sensitive upper main island (8) and the static differential sensitive lower main island (9) are in a balanced state, the differential pressure sensitive auxiliary island (10) has no deflection, the frequency output signal of the sensor remains stable, and the static pressure error after differentiation is stable at the thousandth level (unit: Hz / kPa).
[0060] Differential pressure sensitivity verification:
[0061] See also Figure 12 , showing the differential pressure sensitivity curve in the range of 0 to 300 kPa. Under the fixed condition of static pressure of 15 MPa, the experiment applied a differential pressure of 0 to 300 kPa, and recorded the frequency changes of the compressive stress resonator (13) and the tensile stress resonator (14). The test results show that the differential pressure sensitivity of the sensor reaches more than 26 Hz / kPa, showing excellent micro-differential pressure detection capability. The frequency output signal is linearly related to the differential pressure, and the linearity is better than 99.9%.
[0062] Temperature sensitivity verification:
[0063] See also Figure 13, showing the temperature sensitivity curve under no load (differential pressure is 0 kPa). The abscissa is temperature (°C), and the ordinate is frequency and signal (Hz), showing the variation trends of the compressive stress resonator (13), the tensile stress resonator (14), and their combined frequency within the range of -40°C to 80°C. The experiment was carried out under the constant condition of a static pressure of 15 MPa. Through the temperature cycle test, the frequency drift characteristics of the compressive stress resonator (13) and the tensile stress resonator (14) under no differential pressure load were recorded to verify the cancellation effect of the dual resonator structure on temperature drift. The test results show that the temperature sensitivity under no differential pressure load is only 0.365 Hz / °C, which is significantly better than that of traditional single resonator sensors. The experiment verifies the high stability of the present invention in wide temperature range operation, providing guarantee for high-precision measurement in complex temperature and pressure environments.
[0064] Comprehensive performance analysis:
[0065] Based on the above simulation and experimental results, the differential pressure sensor of the present invention shows extremely low static pressure error and high differential pressure sensitivity in high static pressure environments. The dual resonator structure not only achieves temperature compensation but also significantly improves the measurement accuracy of micro differential pressure.
[0066] The sensor of the present invention can be manufactured by microfabrication technology, featuring miniaturization, low cost, and high stability, and is suitable for high-precision differential pressure measurement in fields such as petrochemical industry, aerospace, and environmental monitoring.
[0067] The above embodiments are only preferred embodiments of the present invention and should not be considered as limiting the scope of implementation of the present invention. All equivalent changes and improvements made in accordance with the scope of the application of the present invention should still fall within the scope covered by the patent of the present invention.
Claims
1. A resonant differential pressure sensor with a low temperature drift characteristic based on a dual resonator structure, characterized in that It includes a glass base (7), a static pressure sensitive pressure sensing layer (6), a double resonator layer (5), a silicon island layer (4), and a differential pressure sensitive pressure sensing layer (3) stacked from bottom to top; on the upper surface of the differential pressure sensitive pressure sensing layer (3), a differential pressure sensitive upper pressure sensing film (2) exposed to the working condition environment is formed; The differential pressure sensitive upper pressure sensing film (2) and the differential pressure sensitive pressure sensing layer (3) are respectively located on the upper side of the silicon island layer (4); The differential pressure sensitive pressure sensing layer (3) is used to sense the differential pressure change, and the static pressure sensitive pressure sensing layer (6) is used to balance the static pressure. The two transfer stress through the silicon island layer (4); The silicon island layer (4) includes a differential pressure sensitive upper main island (8) on the upper surface, a differential pressure sensitive lower main island (9) on the lower surface, and a differential pressure sensitive sub-island (10) connecting the two. A movable structure groove (11) is provided on the periphery of the differential pressure sensitive sub-island (10); an electrode hole (1) is also provided on the silicon island layer (4), and the electrode hole (1) is used to connect an external circuit; The double resonator layer (5) includes a compressive stress resonator (13), a tensile stress resonator (14), a driving electrode (12), a grounding electrode (15), and a detection electrode (19) symmetrically arranged. The compressive stress resonator (13) and the tensile stress resonator (14) are respectively connected to the differential pressure sensitive sub-island (10), and the differential pressure sensitive sub-island (10) transfers stress to the compressive stress resonator (13) and the tensile stress resonator (14); the driving electrode (12) and the grounding electrode (15) form a conduction circuit, and the detection electrode (19) is used to collect the frequency output signals of the compressive stress resonator (13) and the tensile stress resonator (14) and convert them into square wave signals; The glass base (7) is provided with a glass base ventilation hole (22), and the glass base (7) is communicated with the static pressure sensitive pressure sensing layer (6) through the glass base ventilation hole (22) to balance the static pressure.
2. The resonant differential pressure sensor with low temperature drift characteristic based on a dual resonator structure as claimed in claim 1, wherein The glass base (7), the static pressure sensitive pressure sensing layer (6), the double resonator layer (5), the silicon island layer (4), and the differential pressure sensitive pressure sensing layer (3) are fixedly connected by a bonding technique.
3. The resonant differential pressure sensor with low temperature drift characteristic based on a dual resonator structure as claimed in claim 1, wherein The static pressure sensitive pressure sensing layer (6) includes a static pressure sensitive lower pressure sensing film (20) and a static pressure sensitive pressure sensing layer movable groove (21). The static pressure sensitive lower pressure sensing film (20) is communicated with the glass base ventilation hole (22) and is used to sense the external static pressure; the static pressure sensitive pressure sensing layer movable groove (21) provides an elastic deformation space for stress transfer.
4. The resonant differential pressure sensor with low temperature drift characteristics based on a dual resonator structure according to claim 1, characterized in that The double resonator layer (5) is also provided with a tensile stress resonator cover plate (17) and a compressive stress resonator cover plate (18), and the tensile stress resonator cover plate (17) and the compressive stress resonator cover plate (18) are used to protect the resonator and transfer differential pressure stress.
5. The resonant differential pressure sensor with low temperature drift characteristics based on a dual resonator structure according to claim 1, characterized in that The frequency changes of the compressive stress resonator (13) and the tensile stress resonator (14) are opposite at different temperatures. The frequency of the compressive stress resonator (13) decreases with the increase of pressure, and the frequency of the tensile stress resonator (14) increases with the increase of pressure. And the absolute values of the slopes of the frequency changes of the two are equal and opposite in magnitude, and the temperature influence is offset by summation.
6. The resonant differential pressure sensor with low temperature drift characteristics based on a dual resonator structure according to claim 1, wherein When the pressure on the side where the static error sensitive pressure sensing layer (3) is located is greater than the pressure on the side where the static pressure sensitive pressure sensing layer (6) is located, the static error sensitive upper main island (8) and the static error sensitive lower main island (9) move downward, and the differential pressure sensitive sub-island (10) deflects, transmitting stress to the compressive stress resonator (13) and the tensile stress resonator (14), triggering them to enter the working mode.
7. The resonant differential pressure sensor with low temperature drift characteristics based on a dual resonator structure as claimed in claim 1, wherein A double resonator layer mass block (16) is further provided on the double resonator layer (5). The double resonator layer mass block (16) is bonded to the static pressure sensitive pressure sensing layer (6) to transmit the stress caused by the static pressure. When the static pressure sensitive lower pressure sensing film (20) deforms, the stress is transmitted to the static error sensitive lower main island (9) through the double resonator layer mass block (16). When the static error sensitive upper pressure sensing film (2) deforms, the stress is transmitted to the static error sensitive upper main island (8). When the deformation amount of the static error sensitive upper pressure sensing film (2) is the same as the deformation amount of the static pressure sensitive lower pressure sensing film (20) under the static pressure, static pressure balance is achieved.
8. The resonant differential pressure sensor with low temperature drift characteristics based on a dual resonator structure according to claim 1, wherein The driving electrode (12) applies a 5V voltage to form a circuit with the grounding electrode (15) to collect the frequency signals of the compressive stress resonator (13) and the tensile stress resonator (14).
9. The resonant differential pressure sensor with low temperature drift characteristic based on a dual resonator structure according to claim 1, wherein The static error sensitive upper pressure sensing film (2) and the static pressure sensitive lower pressure sensing film (20) are made of highly elastic single crystal silicon material to improve the response speed and sensitivity to pressure changes.