Resonant pressure sensor and method of manufacturing the same

Abstract

The application relates to the technical field of sensors, and provides a resonant pressure sensor and a manufacturing method thereof. The resonant pressure sensor comprises a cap layer, a pressure sensing layer and a resonant tuning fork assembly. The pressure sensing layer is used for sensing the change of input force, and is connected to the cap layer. A vacuum chamber is formed between the cap layer and the pressure sensing layer. The pressure sensing layer is provided with at least two bosses and at least two first grooves. The bosses and the first grooves are arranged in one-to-one correspondence. The bosses are located in the vacuum chamber. The first grooves are arranged on the side of the pressure sensing layer away from the cap layer. The bosses and the first grooves are sequentially arranged in the direction away from the input force. The resonant tuning fork assembly is arranged in the vacuum chamber. The at least two bosses are arranged on the opposite sides of the resonant tuning fork assembly. The resonant tuning fork assembly is connected to the bosses. The resonant tuning fork assembly is used for connecting a first external circuit. The resonant pressure sensor can convert the tensile and compressive deformation of the pressure sensing layer into bending deformation, thereby improving the sensitivity of the pressure sensing layer.

Description

Technical Field

[0001] This invention relates to the field of sensor technology, and in particular to a resonant pressure sensor and its manufacturing method. Background Technology

[0002] Resonant pressure sensors, such as quartz resonant pressure sensors, use a pressure-sensitive diaphragm to sense the pressure of the fluid being measured. A force-sensitive quartz resonant beam converts the strain of the diaphragm caused by the pressure into a frequency change, directly outputting a frequency proportional to the magnitude of the measured pressure. A circuit detects the frequency change of the quartz resonant beam and converts it into an electrical signal corresponding to the pressure value, thus realizing the detection of the fluid pressure. Quartz resonant pressure sensors do not have the speed increment error caused by analog-to-digital conversion, are compatible with high-speed digital circuits, have a small temperature drift coefficient, and offer advantages such as high accuracy, low cost, and small size.

[0003] In related technologies, quartz resonant pressure sensors employ a sensitive structure consisting of a tuning fork beam and a pressure-sensitive diaphragm. The tuning fork beam is positioned on the pressure-sensitive diaphragm, and tensile or compressive stress is applied to the beam through the diaphragm to change its resonant frequency. However, tensile or compressive deformation can create localized stress concentrations in the pressure-sensitive diaphragm, potentially damaging it and hindering the improvement of the sensor's sensitivity. Furthermore, the all-quartz sensitive structure uses a circular design, resulting in significant losses at the pressure-sensitive diaphragm, making it difficult to improve detection accuracy. Summary of the Invention

[0004] This invention provides a resonant pressure sensor to address the shortcomings of existing resonant pressure sensors in terms of detection accuracy and sensitivity. The resonant pressure sensor provided in this invention has a simple structure and can convert the tensile and compressive deformation of the pressure-sensitive layer into bending deformation, thereby improving the sensitivity of the pressure-sensitive layer.

[0005] A first aspect of the present invention provides a resonant pressure sensor.

[0006] Cap layer;

[0007] A pressure-sensitive layer is used to sense changes in input force. The pressure-sensitive layer is connected to the capping layer, and a vacuum chamber is formed between the capping layer and the pressure-sensitive layer. The pressure-sensitive layer is provided with at least two protrusions and at least two first grooves. The protrusions and the first grooves are arranged in a one-to-one correspondence. The protrusions are located in the vacuum chamber, and the first grooves are arranged on the side of the pressure-sensitive layer away from the capping layer. The protrusions and the first grooves are arranged sequentially along the direction away from the input force.

[0008] A resonant tuning fork assembly is disposed within the vacuum chamber, with at least two bosses disposed on opposite sides of the resonant tuning fork assembly. The resonant tuning fork assembly is connected to the bosses and is used to connect to a first external circuit.

[0009] According to one embodiment of the present invention, two bosses are provided, two first grooves are provided, the two bosses are disposed opposite to each other on both sides of the input force, and the input direction of the input force is perpendicular to the line connecting the two bosses.

[0010] According to one embodiment of the present invention, a second groove is formed on the side of the pressure-sensitive layer facing the vacuum chamber, the boss is disposed in the second groove, and the first groove and the second groove are spaced apart.

[0011] According to one embodiment of the present invention, the first sidewall of the first groove near the second groove is parallel to the second sidewall of the second groove near the first groove, and the distance between the first sidewall and the second sidewall is greater than or equal to 100 micrometers and less than or equal to 1800 micrometers.

[0012] According to one embodiment of the present invention, the depth of the first groove is the same as the height of the boss, and / or the depth of the second groove is the same as the height of the boss.

[0013] According to one embodiment of the present invention, the thickness of the pressure-sensitive layer is greater than or equal to 220 micrometers and less than or equal to 1920 micrometers, and the height of the boss is greater than or equal to 120 micrometers and less than or equal to 240 micrometers.

[0014] According to one embodiment of the present invention, the distance between the two first grooves is greater than or equal to 5000 micrometers and less than or equal to 7000 micrometers, and the length of the opening end of the first groove is greater than or equal to 1000 micrometers and less than or equal to 2000 micrometers.

[0015] According to an embodiment of the present invention, the resonant tuning fork assembly includes a tuning fork vibrating beam assembly, a first folded beam, and a second folded beam. One end of the tuning fork vibrating beam assembly is connected to the boss through the first folded beam, and the other end of the tuning fork vibrating beam assembly is connected to the boss through the second folded beam. The first folded beam, the second folded beam, and the tuning fork vibrating beam assembly are suspended in mid-air.

[0016] According to an embodiment of the present invention, the resonant tuning fork assembly further includes a boss docking component. At least one of the first folded beam and the second folded beam is connected to the boss through the boss docking component. Two bosses are provided, and two boss docking components are provided. The bosses and the boss docking components are provided in a one-to-one correspondence. The tuning fork vibrating beam assembly is disposed between the two boss docking components.

[0017] A second aspect of the present invention provides a method for manufacturing a resonant pressure sensor as described in any of the preceding embodiments, comprising:

[0018] The protrusion is formed on the pressure-sensitive layer;

[0019] The resonant tuning fork assembly is disposed on the pressure-sensitive layer, wherein the resonant tuning fork assembly is connected to the boss;

[0020] The capping layer is disposed on the pressure-sensitive layer, wherein the capping layer is connected to the pressure-sensitive layer.

[0021] The above-described one or more technical solutions in the embodiments of the present invention have at least one of the following technical effects:

[0022] (1) The resonant pressure sensor provided in this embodiment of the invention has a boss and a first groove arranged sequentially along the direction away from the input force. At least two bosses are arranged on opposite sides of the resonant tuning fork assembly, that is, a boss and a first groove are arranged on opposite sides of the resonant tuning fork assembly. When an input force is input, the boss rotates towards the first groove, causing the pressure-sensitive layer to bend and deform. Compared to the tensile and compressive deformation of the pressure-sensitive layer under tensile and compressive stress, the bending deformation of the pressure-sensitive layer allows the entire surface of the pressure-sensitive layer to participate in the pressure-sensitive deformation, thereby increasing the surface area of ​​the sensing deformation. In this embodiment, under the same input force, compared to the deformation of the pressure-sensitive layer in the length direction under tensile and compressive deformation, the bending deformation of the pressure-sensitive layer can extend in multiple directions, with a larger deformation, that is, a greater degree of deformation of the pressure-sensitive layer, which can improve the sensitivity of the pressure-sensitive layer to the input force.

[0023] (2) The pressure-sensitive layer is provided with bosses, and the resonant tuning fork assembly is connected to the bosses. The input force is used to drive the pressure-sensitive layer to strain, causing the bosses to move closer or further apart, thereby causing strain in the tuning fork beam assembly and changing the frequency of the tuning fork beam assembly. The first external circuit detects the magnitude of the input force by detecting the frequency. Compared to the resonant tuning fork assembly being connected to the planar pressure-sensitive layer, under the same input force, the bosses can form a concentrated force application point relative to the plane, optimizing the transmission of pressure. The bosses can increase the deformation of the pressure-sensitive layer and improve the strain degree of the pressure-sensitive layer, thereby making the resonant tuning fork assembly respond quickly to the input force and having high detection accuracy and sensitivity of the input force.

[0024] (3) The first folding beam and the second folding beam, together with the boss, form a lever multiplication structure, which can amplify the input force, thereby increasing the force of the input force on the tuning fork vibrating beam assembly. The tuning fork vibrating beam assembly is subjected to a large force and has a large deformation, thereby improving the detection accuracy and sensitivity of the tuning fork vibrating beam assembly. Attached Figure Description

[0025] To more clearly illustrate the technical solutions in this invention 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 some embodiments of this invention. For those skilled in the art, other drawings can be obtained from these drawings without creative effort.

[0026] Figure 1 This is a schematic diagram of the structure of the first resonant pressure sensor in the prior art;

[0027] Figure 2 This is a schematic diagram of the structure of the second type of resonant pressure sensor in the prior art;

[0028] Figure 3 This is a schematic diagram of the structure of the third type of resonant pressure sensor in the prior art;

[0029] Figure 4 This is a cross-sectional view of the first type of resonant pressure sensor provided in an embodiment of the present invention;

[0030] Figure 5 This is a cross-sectional view of the second type of resonant pressure sensor provided in this embodiment of the invention;

[0031] Figure 6 This is a top view of the resonant pressure sensor after removing the capping layer, as provided in an embodiment of the present invention;

[0032] Figure 7 This is a schematic diagram of the resonant tuning fork assembly provided in an embodiment of the present invention;

[0033] Figure 8 This is a top view of the resonant pressure sensor provided in this embodiment of the invention after removing the capping layer and the resonant tuning fork assembly;

[0034] Figure 9 This is a cross-sectional view of the first pressure-sensitive layer and gold-plated electrode layer provided in the embodiments of the present invention;

[0035] Figure 10 This is a cross-sectional view of the second pressure-sensitive layer and gold-plated electrode layer provided in the embodiments of the present invention;

[0036] Figure 11 This is a top view of the guide layer provided in an embodiment of the present invention;

[0037] Figure 12 This is a cross-sectional view of the guide layer provided in an embodiment of the present invention;

[0038] Figure 13 This is a bottom view of the capping layer provided in an embodiment of the present invention.

[0039] Figure label:

[0040] 1. Vibrating beam; 2. Pressure-sensitive diaphragm; 3. Metal counterweight; 4. Quartz vibrating beam; 5. Metal flexible head; 6. Metal Bourdon tube; 7. Vacuum chamber; 8. External input pressure; 9. Temperature-measuring tuning fork; 10. Left sensing diaphragm; 11. Left sensing tang; 12. Right sensing tang; 13. Right sensing diaphragm; 14. Cylindrical vacuum chamber; 15. Upper electrode of resonator; 16. Resonator; 17. Lower electrode of resonator; 18. End cover plate; 19. Excitation circuit; 20. Frequency measurement circuit; 21. Sensing structure;

[0041] 100. Sealing layer; 110. Vacuum chamber; 120. Getter layer; 130. Cavity;

[0042] 200, Pressure-sensitive layer; 210, Boss; 220, Second pressure-sensing vibration pad; 230, Third pressure-sensing vibration pad; 240, Second temperature-sensing vibration pad; 250, Third temperature-sensing vibration pad; 260, Electrode lead; 270, First groove; 280, Second groove; 290, Gold-plated electrode layer;

[0043] 300. Resonant tuning fork assembly; 301. First excitation electrode; 311. Tuning fork vibrating beam; 312. First tuning fork node block; 313. Second tuning fork node block; 314. First tuning fork stress isolation beam; 315. Second tuning fork stress isolation beam; 316. First folded beam node block; 317. Second folded beam node block; 321. First folded beam; 322. Second folded beam; 331. First boss mating component; 3311. First pressure-measuring excitation pad; 332. Second boss mating component; 3321. First temperature-measuring excitation pad; 333. Wire; 340. Temperature-measuring tuning fork; 341. Second excitation electrode; 350. Counterweight tuning fork;

[0044] 400, Guiding layer; 410, Pressure-sensing chamber; 420, Guiding channel; 430, First isolation groove; 440, Second isolation groove;

[0045] 510, First glass paste; 520, Second glass paste; 530, Third glass paste. Detailed Implementation

[0046] To make the objectives, technical solutions, and advantages of this invention clearer, the technical solutions of this invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some, not all, of the embodiments of this invention. All other embodiments obtained by those skilled in the art based on the embodiments of this invention without creative effort are within the scope of protection of this invention.

[0047] In the description of the embodiments of the present invention, it should be noted that the terms "center," "longitudinal," "lateral," "upper," "lower," "front," "rear," "left," "right," "vertical," "horizontal," "top," "bottom," "inner," and "outer," etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are only for the convenience of describing the embodiments of the present invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on the embodiments of the present invention. In addition, the terms "first," "second," and "third" are used for descriptive purposes only and should not be construed as indicating or implying relative importance.

[0048] In the description of the embodiments of the present invention, it should be noted that, unless otherwise explicitly specified and limited, the terms "connected" and "linked" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium. Those skilled in the art can understand the specific meaning of the above terms in the embodiments of the present invention based on the specific circumstances.

[0049] In embodiments of the present invention, unless otherwise explicitly specified and limited, "above" or "below" the second feature can mean that the first feature is in direct contact with the second feature, or that the first feature is in indirect contact with the second feature through an intermediate medium. Furthermore, "above," "on top of," and "over" the second feature can mean that the first feature is directly above or diagonally above the second feature, or simply that the first feature is at a higher horizontal level than the second feature. "Below," "below," and "under" the second feature can mean that the first feature is directly below or diagonally below the second feature, or simply that the first feature is at a lower horizontal level than the second feature.

[0050] In the description of this specification, the references to terms such as "one embodiment," "some embodiments," "example," "specific example," or "some examples," etc., refer to specific features, structures, materials, or characteristics described in connection with that embodiment or example, which are included in at least one embodiment or example of the present invention. In this specification, the illustrative expressions of the above terms do not necessarily refer to the same embodiment or example. Furthermore, the specific features, structures, materials, or characteristics described may be combined in any suitable manner in one or more embodiments or examples. Moreover, without contradiction, those skilled in the art can combine and integrate the different embodiments or examples described in this specification, as well as the features of different embodiments or examples.

[0051] Before describing the resonant pressure sensor provided in the embodiments of the present invention, the working principle of the resonant pressure sensor will be explained.

[0052] refer to Figure 1 As shown, the vibrating beam 1 is bonded to the pressure-sensitive diaphragm 2. When an external force P is applied, the force P causes strain in the pressure-sensitive diaphragm 2, which then tends to crack to both sides. Dividing the force P by its position, the pressure-sensitive diaphragm 2 to the left of the force P will move to the left, and the pressure-sensitive diaphragm 2 to the right of the force P will move to the right, thus subjecting the vibrating beam 1, which is bonded to the pressure-sensitive diaphragm 2, to tensile stress. Under this tensile stress, the resonant frequency of the vibrating beam 1 increases.

[0053] When the external force P decreases, the pressure-sensitive diaphragm 2 on the left side of the external force P will move to the right, and the pressure-sensitive diaphragm 2 on the right side of the external force P will move to the left, thus causing the vibrating beam 1, which is adhered to the pressure-sensitive diaphragm 2, to experience compressive stress. Under the action of compressive stress, the resonant frequency of the vibrating beam 1 increases.

[0054] The change in the resonant frequency of vibrating beam 1 can reflect the magnitude of the input force. Vibrating beam 1 is connected to an external circuit, so that the magnitude of the external force P can be detected by detecting the resonant frequency of vibrating beam 1 through the external circuit.

[0055] Before describing the resonant pressure sensor provided in the embodiments of the present invention, a quartz resonant pressure sensor will be used as an example to describe the resonant pressure sensor in the related art.

[0056] Quartz resonant pressure sensor sensitive structures can be divided into two types: quartz resonant beam + metal pressure-sensitive diaphragm structure and quartz resonant beam + quartz pressure-sensitive diaphragm structure. American company Panos uses the quartz resonant beam + metal pressure-sensitive diaphragm structure, while American company Quartzdyne and Japanese company EPSON use the all-quartz structure of quartz resonant beam + quartz pressure-sensitive diaphragm.

[0057] The application of quartz resonant pressure sensors has expanded from the aviation field, such as aircraft atmospheric data systems, pressure calibration systems, and engine testing, to the petrochemical field, such as industrial process monitoring. The quartz resonant pressure sensor provided in this embodiment of the invention is mainly aimed at tactical applications with large impacts and strong vibrations. Its typical mechanical environment is (1) random vibration: bandwidth 20Hz~2kHz, effective value 6.06g; (2) impact: half-sine peak value 200g, half-wave time 6ms.

[0058] Founded in 1972 by Jerome M. Paros, the American company Paros Corporation transitioned to the research and production of quartz resonant pressure sensors, drawing on his early engineering experience in developing digital force sensors. The company's pressure sensor sensor sensor head uses a combined structure of metal pressure-sensing element and quartz resonant beam.

[0059] like Figure 2As shown, the pressure sensor sensor head includes: a metal counterweight 3, a quartz vibrating beam 4, a metal flexible head 5, a metal Bourdon tube 6, a vacuum chamber 7, and a temperature-sensing tuning fork 9.

[0060] The device employs a metal Bourdon tube 6 and a metal flexible head 5 as the metal pressure-sensing element. A quartz resonant beam 4 is rigidly connected to the metal pressure-sensing element. When the external input pressure 8 changes, the metal pressure-sensing element deforms, causing a change in the axial stress of the quartz resonant beam 4 fixed at both ends. This results in a change in the output frequency of the quartz resonant beam 4, thus achieving pressure measurement. The meter also includes a self-balancing counterweight and impact protection device, enabling the sensor to operate under high overload, impact, and vibration environments. The product is used in atmospheric data systems, aero-engine testing, pressure calibration equipment, satellite micro-propulsion measurement systems, and tsunami monitoring systems, among others.

[0061] The advantage of this structure is that the use of a metal membrane structure can improve the sensitivity of the product. The disadvantage is that the metal pressure-sensitive membrane structure does not match the thermal expansion coefficient of the metal with the quartz vibrating beam 4, and thermal stress causes zero-position drift.

[0062] Quartzdyne, Inc. was founded in 1990 by Errol P. EerNisse. EerNisse initially worked at Sandia National Laboratories in the United States, conducting research on radiation resistance of piezoelectric and semiconductor devices. After 1979, he founded several companies specializing in the development and production of quartz resonant pressure sensors for measuring acceleration, pressure, and temperature. His products are used in the downhole oil and gas industry, logging and drilling, seabed exploration, process control, and energy development.

[0063] The sensitive structure of the quartz resonant pressure sensor developed by this company adopts an all-quartz design. It is a quartz resonator operating in thickness shear mode, such as... Figure 3 As shown, the sensitive meter head includes: a left sensing membrane 10, a left sensing edge 11, a right sensing edge 12, a right sensing membrane 13, a cylindrical vacuum chamber 14, an upper electrode of a resonator 15, a resonator 16, a lower electrode of a resonator 17, an end cover plate 18, an excitation circuit 19, a frequency measurement circuit 20, and a sensitive structure 21.

[0064] The quartz resonant pressure sensor consists of an AT-cut disc-shaped resonator, a thin-walled cylinder with tangled edges, and an end cover plate 18. The resonant disc separates the central part of the thin-walled cylinder, and the left and right tangled edges on the outer surface of the quartz cylinder sense the pressure, which causes the radial compressive stress of the disc-shaped quartz resonator to change, thereby changing the resonant frequency and thus realizing pressure measurement.

[0065] The advantages of this structure are that it uses an all-quartz structure and has good material matching for the sensitive structure. The disadvantages are that it uses traditional grinding processing, which is not suitable for processing ultra-thin pressure-sensitive diaphragms with low to medium ranges, and the processing efficiency of a single unit is low, making it unsuitable for mass production.

[0066] Therefore, it is evident that the existing sensitive structure of quartz resonant pressure sensors has the following shortcomings:

[0067] 1. The existing metal wave lamp tube + quartz vibrating beam structure cannot solve the problem of thermal expansion coefficient matching. Due to the use of multiple materials, the thermal expansion coefficients of the materials themselves cannot be completely matched. The use of process adhesives to bond them cannot effectively guarantee the matching of thermal expansion coefficients, resulting in a relatively large temperature drift coefficient when changing over the entire temperature range.

[0068] 2. Existing all-quartz sensitive structures use a circular structure, which results in significant losses at the base. The manufacturing process of integrated structures is difficult, and the processing of ultra-thin pressure-sensitive films is challenging.

[0069] 3. Existing sensitive structures lack effective temperature sensing elements, and using separate temperature-sensing tuning forks or temperature-sensing crystal oscillators cannot achieve effective measurement of the core temperature of the sensitive structure itself.

[0070] 4. Existing sensitive structures rely solely on the design of pressure-sensitive membranes and the stiffness of the vibrating beams to achieve limiting and stopping, thus preventing the impact of external vibrations and impacts on the sensitive structures. This makes it impossible to achieve a "soft landing" for the resonant structure, which makes the resonator extremely prone to breakage under large vibrations or impacts, leading to the failure of the entire instrument.

[0071] Below, in conjunction with Figures 4 to 13 The resonant tuning fork sensor of the first aspect of the present invention will be described.

[0072] refer to Figure 5 and Figure 6 As shown, the present invention provides a resonant pressure sensor according to a first aspect embodiment, including a capping layer 100, a pressure-sensing layer 200, and a resonant tuning fork assembly 300.

[0073] The pressure-sensing layer 200 is used to sense changes in input force. The pressure-sensing layer 200 is connected to the capping layer 100, and a vacuum chamber 110 is formed between the capping layer 100 and the pressure-sensing layer 200. The pressure-sensing layer 200 is provided with at least two protrusions 210 and at least two first grooves 270, with each protrusion 210 corresponding to the other. The protrusions 210 are located within the vacuum chamber 110, and the first grooves 270 are located on the side of the pressure-sensing layer 200 away from the capping layer 100. The protrusions 210 and first grooves 270 are sequentially arranged along the direction away from the input force. A resonant tuning fork assembly 300 is disposed within the vacuum chamber 110. At least two protrusions 210 are located on opposite sides of the resonant tuning fork assembly 300. The resonant tuning fork assembly 300 is connected to the protrusions 210 and is used to connect to a first external circuit.

[0074] In this embodiment, a boss 210 and a first groove 270 are sequentially arranged along the direction away from the input force. At least two bosses 210 are arranged on opposite sides of the resonant tuning fork assembly 300, that is, a boss 210 and a first groove 270 are provided on opposite sides of the resonant tuning fork assembly 300. When an input force is applied, the boss 210 rotates towards the first groove 270, causing the pressure-sensitive layer 200 to bend and deform.

[0075] Compared to the tensile and compressive deformation of the pressure-sensitive layer 200 under tensile and compressive stress, the bending deformation of the pressure-sensitive layer 200 allows its entire surface to participate in pressure-sensitive deformation, thereby increasing the surface area for inductive deformation. In this embodiment, under the same input force, compared to the deformation of the tensile and compressive pressure-sensitive layer 200 in the length direction, the bending deformation of the pressure-sensitive layer 200 can extend in multiple directions, resulting in a larger deformation. That is, the degree of deformation of the pressure-sensitive layer 200 is greater, which can improve the sensitivity of the pressure-sensitive layer 200 to the input force.

[0076] Preferably, combined with Figure 5 Two bosses 210 are provided, and two first grooves 270 are provided. The two bosses 210 are positioned opposite each other on both sides of the input force, and the input direction of the input force is perpendicular to the line connecting the two bosses 210.

[0077] In this embodiment, the input force is located between the two bosses 210, and the bosses 210 and the first groove 270 are sequentially arranged along the direction away from the input force. Figure 5 That is, the input force is set in the middle of the two protrusions 210, a first groove 270 is provided on the left side of the left protrusion 210, and a first groove 270 is provided on the right side of the right protrusion 210.

[0078] When an input force is applied, it applies pressure to the pressure-sensitive layer 200 from bottom to top, with the pressure applied between the two protrusions 210. At this time, the pressure-sensitive layer 200 undergoes strain, and the protrusions 210 move away from each other.

[0079] Taking the right-side boss 210 as an example, a first groove 270 is provided on the right side of the right-side boss 210. When an input force is applied, the right-side boss 210 will rotate in the direction of the first groove 270 on the right side, that is, the right-side boss 210 will rotate clockwise.

[0080] Taking the left boss 210 as an example, a first groove 270 is provided on the left side of the left boss 210. When an input force is applied, the left boss 210 will rotate in the direction of the first groove 270 on the left, that is, the left boss 210 will rotate counterclockwise.

[0081] In this embodiment, the right boss 210 rotates clockwise and the left boss 210 rotates counterclockwise, causing the sensing membrane to bend and deform. The boss 210, in conjunction with the first groove 270, can increase the deformation degree of the pressure-sensitive layer 200, thereby increasing the sensitivity of the pressure-sensitive layer 200 to the input force and thus improving the detection accuracy of the resonant pressure sensor.

[0082] Specifically, when assembly stress or thermal stress is transmitted to the external pressure-sensitive layer 200, the bending deformation of the pressure-sensitive layer 200 can disperse the stress, absorb the stress, and reduce the impact of stress on the pressure-sensitive layer 200 and the resonant tuning fork assembly 300. Simultaneously, when vibration or impact is transmitted to the pressure-sensitive layer 200, the bending deformation of the pressure-sensitive layer 200 can absorb the energy of the vibration or impact, slowing down the energy transmission speed, thereby protecting the pressure-sensitive layer 200 and the resonant tuning fork assembly 300 and preventing the resonant tuning fork assembly 300 from breaking, which would cause the resonant pressure sensor to malfunction.

[0083] It should be noted that the direction of the input force can be perpendicular to the line connecting the two bosses 210, or it can form an acute or obtuse angle with the line connecting the two bosses 210. The direction of the input force can be located between the two bosses 210, and there is no limitation here.

[0084] A second groove 280 is formed on the side of the pressure-sensitive layer 200 facing the vacuum chamber, and a boss 210 is disposed within the second groove 280. The first groove 270 and the second groove 280 are spaced apart. (Reference) Figure 5 As shown, the boss 210 is disposed within the second groove 280. The second groove 280 can reduce the thickness of the pressure-sensitive layer 200, thereby reducing the distance between the boss 210 and the first groove 270. In this embodiment, the small distance between the boss 210 and the first groove 270 means that when the boss 210 rotates towards the first groove 270, the resistance encountered during the rotation of the boss 210 is small, thereby further increasing the deformation of the pressure-sensitive layer 200 and further improving the sensitivity of the pressure-sensitive layer 200.

[0085] The first sidewall of the first groove 270 near the second groove 280 is parallel to the second sidewall of the second groove 280 near the first groove 270. (Reference) Figure 5 The first sidewall is parallel to the second sidewall, which improves the stability of the boss 210's rotation and helps reduce the tilting or offset of the boss 210 during rotation. The distance between the first sidewall and the second sidewall is greater than or equal to 100 micrometers and less than or equal to 1800 micrometers, which reduces the resistance during the rotation of the boss 210, thereby improving the smoothness of the boss 210's rotation and thus improving the stability of the bending deformation of the pressure-sensitive layer 200.

[0086] Combination Figure 5The depth of the first groove 270 and the height of the boss 210 are the same, which helps to maintain the stability of the pressure-sensitive layer 200. At the same time, the structure of the first groove 270 and the boss 210 is simple and easy to form, which can simplify the manufacturing process. Of course, in some other embodiments, the depth of the first groove 270 and the height of the boss 210 may be different.

[0087] The cross-sectional area of ​​the first groove 270 can be trapezoidal, rectangular, pentagonal, or other shapes. The cross-sectional area of ​​the boss 210 can also be trapezoidal, rectangular, pentagonal, or other shapes. The cross-sectional area of ​​the first groove 270 can be the same as or different from that of the boss 210.

[0088] Combination Figure 5 The depth of the second groove 280 is the same as the height of the boss 210, which helps to maintain the stability of the pressure-sensitive layer 200. At the same time, the structure of the first groove 270 and the boss 210 is simple and easy to form, which can simplify the manufacturing process. Of course, the height of the boss 210 can also be greater than the depth of the first groove 270, in which case the top surface of the boss 210 is higher than the top surface of the first groove 270.

[0089] Of course, the depth of the first groove 270, the depth of the second groove 280, and the height of the boss 210 can be the same, which can effectively improve the structural consistency of the pressure-sensitive layer 200, make the deformation of the pressure-sensitive layer 200 more controllable and predictable, and at the same time improve the stability and reliability of the deformation of the pressure-sensitive layer 200 when it is bent.

[0090] Preferably, the thickness of the pressure-sensitive layer 200 is greater than or equal to 220 micrometers and less than or equal to 1920 micrometers, and the height of the boss 210 is greater than or equal to 120 micrometers and less than or equal to 240 micrometers. This not only ensures that the strength of the pressure-sensitive layer 200 meets the requirements, but also ensures that the boss 210 can rotate in conjunction with the first groove 270 to achieve bending deformation of the pressure-sensitive layer 200.

[0091] Preferably, the depth of the first groove 270 is greater than or equal to 120 micrometers and less than or equal to 240 micrometers. The depth of the first groove 270 may be the same as or different from the height of the boss 210. Similarly, the depth of the second groove 280 is greater than or equal to 120 micrometers and less than or equal to 240 micrometers. The depth of the second groove 280 may be the same as or different from the height of the boss 210.

[0092] Preferably, the distance between the two first grooves 270 is greater than or equal to 5000 micrometers and less than or equal to 7000 micrometers, and the length of the open end of the first groove 270 is greater than or equal to 1000 micrometers and less than or equal to 2000 micrometers. Figure 10In the figure, e12 is the distance between the two first grooves 270, and e11 is the length of the groove opening.

[0093] It should be noted that the distance between the two first grooves 270 can be the distance between the farthest ends of the two first grooves 270, such as: [The text abruptly ends here, likely due to an incomplete sentence or a formatting error.] Figure 10 The distance between the two first grooves 270 at their farthest ends is e12 as marked in the diagram; it can also be the distance between the two central axes of the two first grooves 270; or it can be the distance between the two first grooves 270 at their closest ends, such as: combining Figure 10 It can be the distance between the right end of the first groove 270 on the left and the left end of the first groove 270 on the right.

[0094] The resonant tuning fork assembly 300 is disposed inside the vacuum chamber 110, and the boss 210 is disposed on the opposite side of the resonant tuning fork assembly 300. The resonant tuning fork assembly 300 is used to connect to the first external circuit. The resonant tuning fork assembly 300 includes a tuning fork vibrating beam assembly, a first folded beam 321 and a second folded beam 322. One end of the resonant tuning fork assembly 300 is connected to the boss 210 through the first folded beam 321, and the other end of the resonant tuning fork assembly 300 is connected to the boss 210 through the second folded beam 322. The resonant tuning fork assembly 300 is suspended.

[0095] In this embodiment, the input force is used to drive the pressure-sensitive layer 200 to strain, so that the bosses 210 move closer or further apart. The bosses 210 cause strain in the tuning fork beam assembly, and the frequency of the tuning fork beam assembly changes. The first external circuit detects the magnitude of the input force by detecting the frequency.

[0096] The resonant pressure sensor provided in this embodiment of the invention has a pressure-sensing layer 200 with a boss 210 for sensing changes in input force. A resonant tuning fork assembly 300 is connected to the boss 210 of the pressure-sensing layer 200. The resonant tuning fork assembly 300 includes a tuning fork vibrating beam assembly, a first folded beam 321, and a second folded beam 322. The tuning fork vibrating beam assembly is connected to the boss 210 via the first folded beam 321 and the second folded beam 322. In the resonant pressure sensor provided in this embodiment of the invention, the tuning fork vibrating beam assembly is connected to the first folded beam 321 and the second folded beam 322. When vibration or impact is transmitted to the first folded beam 321 and the second folded beam 322, the first folded beam 321 and the second folded beam 322 can bend or undergo elastic deformation to absorb stress. The first folded beam 321 and the second folded beam 322 can absorb energy, achieving vibration isolation and effectively preventing damage to the tuning fork vibrating beam assembly from external impacts. This helps protect the resonant pressure sensor and ensures its proper operation.

[0097] It is understandable that assembly stress will exist during the assembly process. That is, during the assembly process, incomplete matching or other factors may cause assembly stress in the pressure-sensitive layer 200, which will cause over-positioning of the pressure-sensitive layer 200, resulting in twisting and deformation of the pressure-sensitive layer 200. In this embodiment, the first folding beam 321 and the second folding beam 322 can not only reduce the impact of vibration or impact on the tuning fork vibrating beam assembly, but also effectively absorb assembly stress, reducing the impact of assembly stress on the tuning fork vibrating beam assembly.

[0098] Meanwhile, temperature changes can cause internal stress in an object. For example, when an object is affected by temperature changes, internal stress arises due to thermal expansion or contraction, which is called thermal stress. In this embodiment, the resonant tuning fork assembly 300 is a quartz resonant tuning fork assembly 300. When the resonant pressure sensor undergoes high and low temperature tests, the presence of thermal stress can cause the pressure-sensing layer 200 to twist and deform. The first folded beam 321 and the second folded beam 322 can also absorb the thermal stress, reducing its impact on the tuning fork vibrating beam assembly.

[0099] The pressure-sensitive layer 200 is provided with bosses 210, and the resonant tuning fork assembly 300 is connected to the bosses 210. Input force drives the pressure-sensitive layer 200 to strain, causing the bosses 210 to move closer or further apart, thus straining the tuning fork beam assembly and changing its frequency. The first external circuit detects the magnitude of the input force by detecting the frequency. Compared to the resonant tuning fork assembly 300 being connected to the planar pressure-sensitive layer 200, under the same input force, the bosses 210 can form a concentrated force application point relative to the plane, optimizing pressure transmission. The simple structure of the bosses 210 increases the deformation of the pressure-sensitive layer 200, improves its sensitivity, and enhances the strain response of the resonant tuning fork assembly 300, resulting in a faster response to the input force and higher detection accuracy and sensitivity.

[0100] Sensitivity can be understood as the degree of response of the pressure-sensitive layer 200 to an input force. For example, under the same input force, the greater the deformation and the greater the deformation of the pressure-sensitive layer 200, the higher its sensitivity to the input force. Conversely, the smaller the deformation and the smaller the deformation of the pressure-sensitive layer 200, the lower its sensitivity to the input force.

[0101] Combination Figure 6 Taking the example of having two bosses 210, a tuning fork beam assembly positioned between the two bosses 210, and the direction of the input force perpendicular to the line connecting the two bosses 210, the working principle of the resonant pressure sensor in this embodiment will be explained.

[0102] refer to Figure 6 As shown, a boss 210 is provided on the left side of the tuning fork resonator assembly, and a boss 210 is also provided on the right side of the tuning fork resonator assembly.

[0103] When an input force is applied, it exerts pressure on the pressure-sensitive layer 200 from bottom to top, with the pressure applied between the two protrusions 210. At this time, the pressure-sensitive layer 200 undergoes strain, and the protrusions 210 move away from each other; the left protrusion 210 moves to the left, and the right protrusion 210 moves to the right. That is, the pressure-sensitive layer 200 is pulled to the left and right, undergoing tensile stress deformation.

[0104] The left-side boss 210 moves to the left. The left-side boss 210 is connected to the first folding beam 321 and the second folding beam 322. The first folding beam 321 pulls the tuning fork resonator assembly downwards and to the left, while the second folding beam 322 pulls it upwards and to the left. The left-side boss 210 moves to the right. The right-side boss 210 is connected to the first folding beam 321 and the second folding beam 322. The first folding beam 321 pulls the tuning fork resonator assembly downwards and to the right, while the second folding beam 322 pulls it upwards and to the right. Through the combined forces of the first folding beams 321 and the second folding beams 322 on both sides, the upper side of the tuning fork resonator assembly experiences a downward force, while the lower side experiences an upward force. This causes compressive stress on the tuning fork resonator assembly, reducing the tuning fork resonant frequency.

[0105] Combination Figure 6 When the input force decreases, the pressure-sensitive layer 200 undergoes strain, and the protrusions 210 move closer to each other. The protrusion 210 on the left moves to the right, and the protrusion 210 on the right moves to the left. That is, the left and right sides of the pressure-sensitive layer 200 move towards the middle, and the pressure-sensitive layer 200 undergoes compressive stress deformation.

[0106] The left boss 210 moves to the right, causing the left first folding beam 321 to push the tuning fork resonator assembly upwards and to the right, and the left second folding beam 322 to push the tuning fork resonator assembly downwards and to the right. The right boss 210 moves to the left, causing the right first folding beam 321 to push the tuning fork resonator assembly upwards and to the left, and the right second folding beam 322 to push the tuning fork resonator assembly downwards and to the left. Through the combined forces of the left and right first folding beams 321 and second folding beams 322, the upper side of the tuning fork resonator assembly experiences an upward force, and the lower side experiences a downward force. The tuning fork resonator assembly is subjected to tensile stress, and the resonant frequency of the tuning fork increases.

[0107] In this embodiment, the first folded beam 321 and the second folded beam 322, together with the boss 210, form a lever multiplier structure. Compared to the input force acting directly on the tuning fork vibrating beam assembly through the pressure-sensitive layer 200, the lever multiplier structure in this embodiment can amplify the input force through the first folded beam 321 and the second folded beam 322, thereby increasing the force exerted by the input force on the tuning fork vibrating beam assembly. The tuning fork vibrating beam assembly experiences a large force and a large deformation, thereby improving the detection accuracy and sensitivity of the tuning fork vibrating beam assembly.

[0108] A vacuum chamber 110 is formed between the capping layer 100 and the pressure-sensing layer 200. This vacuum environment not only helps isolate the resonant tuning fork assembly 300 from external vibrations and impacts, but also prevents impurities (such as gases or liquids that could affect the resonant tuning fork assembly 300's detection) from entering the vacuum chamber 110, thereby further improving the sensitivity and accuracy of the resonant tuning fork assembly 300's detection. Of course, in some other embodiments, a vacuum chamber 110 may not be formed between the capping layer 100 and the pressure-sensing layer 200; instead, an installation space for the resonant tuning fork assembly 300 may be formed between the capping layer 100 and the pressure-sensing layer 200.

[0109] refer to Figure 4 As shown, a getter layer 120 is provided on the side of the capping layer 100 facing the vacuum chamber 110. The getter layer 120 is used to maintain the vacuum in the vacuum chamber 110. In this embodiment, the presence of the getter layer 120 helps to maintain the vacuum in the vacuum chamber 110, reduces the interference of gas on the resonant tuning fork assembly 300, and thus improves the accuracy and stability of the measurement.

[0110] It is understandable that there can be two bosses 210, with the resonant tuning fork assembly 300 positioned between the two bosses 210. There can also be three or four bosses 210, for example, when three bosses 210 are provided, two bosses 210 can be provided on one side of the resonant tuning fork assembly 300. One of the two bosses 210 is connected to one end of the tuning fork vibrating beam assembly via a first folding beam 321, and the other of the two bosses 210 is connected to the other end of the tuning fork vibrating beam assembly via a second folding beam 322. One boss 210 is provided on the other side of the tuning fork vibrating beam assembly, and this boss 210 is connected to the tuning fork vibrating beam assembly via the first folding beam 321 and the second folding beam 322. When an input force is applied, the three bosses 210 can be moved away from each other to cause strain in the resonant tuning fork vibrating beam assembly.

[0111] The number of bosses 210 can be set according to actual needs, such as 2, 3, or 4, and is not limited here. Below, we will describe the resonant tuning fork assembly 300 of this embodiment of the invention using 2 bosses 210 as an example.

[0112] refer to Figure 6 and Figure 7As shown, the resonant tuning fork assembly 300 also includes a boss mating component. At least one of the first folded beam 321 and the second folded beam 322 is connected to the boss 210 through the boss mating component. Two bosses 210 and two boss mating components are provided, with each boss 210 and its mating component corresponding to the other. The tuning fork vibrating beam assembly is positioned between the two boss mating components. In this embodiment, the one-to-one correspondence between the two bosses 210 and their mating components improves the connection strength and stability between the resonant tuning fork assembly 300 and the bosses 210, reducing the loosening of the resonant tuning fork assembly 300. Compared to connecting the first folded beam 321 and the second folded beam 322 to the boss 210, the boss mating component simplifies the manufacturing and installation process, making assembly between the resonant tuning fork assembly 300 and the bosses 210 more convenient, reducing assembly complexity, and helping to improve production efficiency.

[0113] In this configuration, at least one of the first folding beam 321 and the second folding beam 322 is connected to the boss 210 via a boss-connecting component. This connection can be either the first folding beam 321 or the second folding beam 322, or both the first folding beam 321 and the second folding beam 322 can be connected to the boss 210 via boss-connecting components, effectively improving the connection strength. Of course, the first folding beam 321 and the second folding beam 322 can be connected to the boss 210 via a boss-connecting component or directly connected to the boss 210, depending on actual requirements.

[0114] It should be noted that the first folding beam 321 and the second folding beam 322 can be at the same height as the tuning fork vibrating beam assembly, that is, the first folding beam 321, the second folding beam 322 and the tuning fork vibrating beam assembly are located on the same plane, and the pressure transmission effect of the first folding beam 321 and the second folding beam 322 is good. Of course, the tuning fork vibrating beam assembly can also be higher than the boss docking part, or the tuning fork vibrating beam assembly can be lower than the boss docking part, in which case the first folding beam 321 and the second folding beam 322 extend vertically.

[0115] Combination Figure 6 The boss mating component, the first folded beam 321, and the second folded beam 322 are symmetrically distributed around the tuning fork resonator assembly as the center line. In this embodiment, the symmetrical distribution design allows the resonant tuning fork assembly 300 to be subjected to a uniformly distributed force under pressure loading, that is, the input force exerted on the tuning fork resonator assembly is uniform, which helps to improve the deformation stability of the tuning fork resonator assembly, thereby improving the reliability of input force detection. At the same time, the symmetrical distribution allows the first folded beam 321 and the second folded beam 322 to further reduce the impact of vibration, impact, or assembly stress on the tuning fork resonator assembly, improving the stability and durability of the system.

[0116] The boss mating component, the first folded beam 321, and the second folded beam 322 are symmetrically distributed around the tuning fork vibrating beam assembly as the center line. (Reference) Figure 6 As shown, preferably, the two boss mating parts are positioned on the vertical line of the tuning fork resonator assembly, in which case the first folded beam 321 and the second folded beam 322 have the same length. Of course, the two boss mating parts can also be positioned away from the vertical line of the tuning fork resonator assembly, that is, the boss mating parts are close to one end or the other end of the tuning fork resonator assembly, in which case the first folded beam 321 and the second folded beam 322 have different lengths.

[0117] At least one of the first folding beam 321 and the second folding beam 322 has an angle between itself and the boss mating component greater than or equal to 140 degrees and less than or equal to 160 degrees. Preferably, the angle θ between the first folding beam 321 and the second folding beam 322 and the boss mating component is 150 degrees, which can improve the structural stability of the resonant tuning fork assembly 300. Figure 7 The length of the tuning fork vibrating beam assembly is greater than the length of the boss 210. The included angles between the first folding beam 321 and the second folding beam 322 and the boss docking parts are both 150 degrees. When the input force drives the boss 210 to move away from or closer to each other, it can stably apply compressive and tensile stresses to the tuning fork vibrating beam assembly through the first folding beam 321 and the second folding beam 322, thereby ensuring the stability of the pressure detection of the resonant pressure sensor.

[0118] The included angle is not limited to 150 degrees; it can be less than 150 degrees or greater than 150 degrees. The included angles between the first folding beam 321 and the second folding beam 322 and the boss docking component can be the same. In this case, the first folding beam 321, the second folding beam 322, and the boss docking component are symmetrically distributed with the tuning fork vibrating beam assembly as the center line. Of course, the included angles between the first folding beam 321 and the second folding beam 322 and the boss docking component can also be different. For example, the first folding beam 321 forms a first included angle with the boss docking component, and the second folding beam 322 forms a second included angle with the boss docking component. The first included angle can be greater than or less than the second included angle, and the size of the first and second included angles can be selected according to actual needs. The angle range of both the first and second included angles is greater than or equal to 140 degrees and less than or equal to 160 degrees.

[0119] The resonant tuning fork assembly 300 also includes a temperature-sensing tuning fork 340, which is connected to the boss mating component. The temperature-sensing tuning fork 340 is used to detect the temperature of the tuning fork vibrating beam assembly. The resonant frequency of the temperature-sensing tuning fork 340 changes with temperature. By detecting the frequency of the tuning fork's vibration, the temperature of the tuning fork vibrating beam assembly can be detected, thereby achieving temperature compensation for the tuning fork vibrating beam assembly and improving the measurement accuracy of the tuning fork vibrating beam assembly under different temperature conditions.

[0120] In this embodiment, the temperature-sensing tuning fork 340, the boss mating component, and the tuning fork vibrating beam assembly are integrally formed. Compared to a separate temperature-sensing tuning fork 340, that is, compared to the temperature-sensing tuning fork 340 being separately set from the resonant tuning fork assembly 300, the integrally formed structure can reduce thermal resistance, that is, the resistance to heat transfer. This not only increases the time required for heat to be transferred from the tuning fork vibrating beam assembly to the temperature-sensing tuning fork 340, resulting in higher temperature measurement efficiency and sensitivity for the temperature-sensing tuning fork 340, but also reduces heat loss during the transfer process. The temperature-sensing tuning fork 340 can accurately reflect the core temperature of the resonant tuning fork assembly 300 (which can also be understood as the temperature of the tuning fork vibrating beam assembly), thereby improving the detection accuracy of the temperature-sensing tuning fork 340. At the same time, the integrally formed structure can improve the strength and stability of the overall structure, making it difficult for the components to loosen or deform. This helps ensure that the structure of the resonant pressure sensor remains stable under different operating conditions, thereby improving the accuracy of temperature measurement.

[0121] In some embodiments, reference Figure 6 and Figure 7 As shown, the resonant tuning fork assembly 300 also includes a counterweight tuning fork 350, which is connected to the temperature-sensing tuning fork 340 on the opposite side of the boss mating component. Figure 5 It is understandable that the temperature-sensing tuning fork 340 and the counterweight tuning fork 350 are arranged symmetrically. The setting of the counterweight tuning fork 350 can improve the symmetry of the resonant tuning fork assembly 300, thereby helping to reduce the impact of assembly stress on the resonant tuning fork assembly 300.

[0122] Of course, preferably, when the resonant tuning fork assembly 300 also includes a counterweight tuning fork 350, the counterweight tuning fork 350, the temperature measuring tuning fork 340, the boss docking component and the tuning fork vibrating beam assembly are integrally formed.

[0123] The resonant tuning fork assembly 300 is made of one of the following materials: quartz, silicon, ceramic, or silicon carbide. Preferably, the resonant tuning fork assembly 300 is made of quartz, meaning it is a quartz resonant tuning fork assembly 300. In this case, all components of the resonant tuning fork assembly 300 have the same coefficient of thermal expansion. That is, the temperature-sensing tuning fork 340, the counterweight tuning fork 350, the first folding beam 321, the second folding beam 322, the boss mating part, and the tuning fork vibrating beam assembly are made of the same material and have the same coefficient of thermal expansion, thereby further ensuring that the temperature-sensing tuning fork 340 can accurately reflect the temperature of the tuning fork vibrating beam assembly. Of course, the resonant tuning fork assembly 300 can also be a silicon resonant tuning fork assembly 300, a ceramic resonant tuning fork assembly 300, or a silicon carbide resonant tuning fork assembly 300. The material of the resonant tuning fork assembly 300 can be set according to actual needs and is not limited here.

[0124] refer to Figure 6As shown, the tuning fork vibrating beam assembly includes multiple tuning fork vibrating beams 311 arranged side by side. One end of each tuning fork vibrating beam 311 is connected to a first tuning fork node block 312, and the other end is connected to a second tuning fork node block 313. In this embodiment, the first tuning fork node block 312 and the second tuning fork node block 313 provide connection points for the multiple tuning fork vibrating beams 311, which can improve the coordination and consistency of the operation of the multiple tuning forks. This can also be understood as improving the deformation degree of the multiple tuning forks under tensile or compressive stress, thereby ensuring the accuracy of the measurement. Furthermore, by using multiple tuning fork vibrating beams 311, if one tuning fork vibrating beam 311 fails for some reason, the other tuning fork vibrating beams 311 can still operate normally, thus ensuring the normal operation of the resonant pressure sensor.

[0125] The tuning fork vibrating beam 311 is provided with an even number of beams, such as two, four, or six beams. Preferably, the tuning fork vibrating beam 311 is provided with two beams (e.g., Figure 5 As shown, an even number of tuning fork vibrating beams 311 can suppress common-mode error and improve the detection accuracy of the tuning fork vibrating beam 311. Of course, an odd number of tuning fork vibrating beams 311 can also be set, such as three or five tuning fork vibrating beams 311.

[0126] In some other embodiments, a single tuning fork beam 311 may be provided, in which case the tuning fork node block may not be required. The number of tuning fork beams 311 can be set according to actual needs and is not limited here.

[0127] In some embodiments, the first tuning fork node block 312 is connected to the first folded beam 321, and the second tuning fork node block 313 is connected to the second folded beam 322. In this embodiment, the first folded beam 321 and the second folded beam 322 can achieve primary stress absorption and vibration isolation; when stress or vibration is transmitted to the first tuning fork node block 312 and the second tuning fork node block 313, the first tuning fork node block 312 and the second tuning fork node block 313 can absorb and isolate it again. The first folded beam 321, the second folded beam 322, the first tuning fork node block 312 and the second tuning fork node block 313 cooperate to achieve secondary isolation, effectively reducing the impact of external vibration, impact or stress on the tuning fork vibrating beam 311.

[0128] In some embodiments, reference Figure 6 As shown, the first tuning fork node block 312 is connected to the first folded beam node block 316 through the first tuning fork stress isolation beam 314, the second tuning fork node block 313 is connected to the second folded beam node block 317 through the second tuning fork stress isolation beam 315, the first folded beam node block 316 is connected to the first folded beam 321, and the second folded beam node block 317 is connected to the second folded beam 322.

[0129] In this embodiment, firstly, the first folding beam 321 and the second folding beam 322 can absorb stress and isolate vibrations at one stage. Secondly, when stress or vibration is transmitted to the first folding beam node block 316 and the second folding beam node block 317, the first folding beam node block 316 and the second folding beam node block 317 can absorb and isolate it a second time. Then, when stress or vibration is transmitted to the first tuning fork stress isolation beam 314 and the second tuning fork stress isolation beam 315, the first tuning fork stress isolation beam 314 and the second tuning fork stress isolation beam 315 can absorb and isolate it a third time. Finally, when stress or vibration is transmitted to the first tuning fork node block 312 and the second tuning fork node block 313, the first tuning fork node block 312 and the second tuning fork node block 313 can absorb and isolate it a fourth time. In this embodiment, multi-level absorption and isolation of external vibrations, impacts, or stresses can be achieved, which can significantly reduce the impact of external vibrations, impacts, or stresses on the tuning fork vibrating beam 311.

[0130] The resonant tuning fork assembly 300 provided in this embodiment includes a tuning fork vibrating beam assembly and a temperature-sensing tuning fork 340. The tuning fork vibrating beam assembly is connected to a first external circuit, which detects the frequency of the tuning fork vibrating beam assembly to detect the input force. The temperature-sensing tuning fork 340 is connected to a second external circuit, which detects the frequency of the temperature-sensing tuning fork 340 to measure the temperature of the tuning fork vibrating beam assembly, thereby improving the accuracy of temperature compensation and ultimately improving the detection accuracy of the resonant pressure sensor.

[0131] The connection between the tuning fork vibrating beam assembly and the first external circuit, and the connection between the temperature-measuring tuning fork 340 and the second external circuit are described below.

[0132] refer to Figure 6 As shown, the boss mating component includes a first boss mating component 331 and a second boss mating component 332. The first boss mating component 331 is provided with a first pressure-measuring excitation pad 3311, and the second boss mating component 332 is provided with a first temperature-measuring excitation pad 3321.

[0133] The resonant tuning fork assembly 300 has a first excitation electrode 301 on its surface. The first excitation electrode 301 is connected to a first pressure-measuring excitation pad 3311. The first pressure-measuring excitation pad 3311 is connected to a second pressure-measuring excitation pad 220 via a wire 333. The second pressure-measuring excitation pad 220 is connected to the pressure-sensitive layer 200 and is used to connect to a first external circuit. Figure 6As shown in the figure, the first boss mating component 331 is located on the right side of the tuning fork resonator assembly. Two first pressure-measuring excitation pads 3311 are provided on the first boss mating component 331. First excitation electrodes 301 are provided on the surface of the tuning fork resonator assembly and on the surfaces of the first folded beam 321 and the second folded beam 322 on the right side of the tuning fork resonator assembly, to connect the excitation electrodes on the surface of the tuning fork resonator assembly to the first pressure-measuring excitation pads 3311. The first pressure-measuring excitation pads 3311 are connected to the second pressure-measuring excitation pad 220 via wires 333. The second pressure-measuring excitation pad 220 is connected to the pressure-sensitive layer 200 and is used to connect to a first external circuit to detect the frequency of the tuning fork resonator assembly.

[0134] It should be noted that, Figure 6 The black rectangular fill line in the diagram represents the first excitation electrode 301. The fill lines of the first folded beam 321 and the second folded beam 322 on the right side of the tuning fork vibrating beam assembly are different from those on the left side. This means that the first excitation electrode 301 is provided on the right side, but not on the left. Alternatively, it can be understood that the first excitation electrode 301 is provided on the first folded beam 321 and the second folded beam 322 on the side where the first boss mating component 331 is located, to achieve the connection between the excitation electrode on the surface of the tuning fork vibrating beam assembly and the first pressure-measuring excitation pad 3311.

[0135] In some embodiments, reference Figure 4 As shown, the length of the capping layer 100 is less than the length of the pressure-sensing layer 200. The second pressure-sensing excitation pad 220 is electrically connected to the third pressure-sensing excitation pad 230. The second pressure-sensing excitation pad 220 is disposed inside the vacuum chamber 110. The third pressure-sensing excitation pad 230 is connected to the pressure-sensing layer 200. The third pressure-sensing excitation pad 230 is located outside the vacuum chamber 110. The third pressure-sensing excitation pad 230 is connected to the first external circuit.

[0136] Multiple third pressure-sensing excitation pads 230 are provided on the pressure-sensing layer 200, and the multiple third pressure-sensing excitation pads 230 are electrically connected to each other. (Reference) Figure 6 As shown, when two first voltage-measuring excitation pads 3311 are provided, two second voltage-measuring excitation pads 220 are also provided accordingly, and two third voltage-measuring excitation pads 230 are also provided accordingly. The two third voltage-measuring excitation pads 230 are connected to the first external circuit. There are four third voltage-measuring excitation pads 230, two of which are connected to the second voltage-measuring excitation pads 220, and the two third voltage-measuring excitation pads 230 are each connected to one third voltage-measuring excitation pad 230. Figure 6The uppermost and lowermost third pressure-measuring excitation pads 230 can be used to test various performance characteristics of the resonant tuning fork assembly 300. The number of third pressure-measuring excitation pads 230 can be set according to actual needs and is not limited here.

[0137] The surface of the temperature-sensing tuning fork 340 is provided with a second excitation electrode 341. The second excitation electrode 341 is connected to the first temperature-sensing excitation pad 3321. The first temperature-sensing excitation pad 3321 is connected to the second temperature-sensing excitation pad 240 through a wire 333. The second temperature-sensing excitation pad 240 is connected to the pressure-sensitive layer 200. The second temperature-sensing excitation pad 240 is used to connect to the second external circuit.

[0138] In some embodiments, combined with Figure 4 and Figure 6 The length of the capping layer 100 is less than the length of the pressure-sensing layer 200. The second temperature-sensing excitation pad 240 is connected to the third temperature-sensing excitation pad 250. The second temperature-sensing excitation pad 240 is disposed inside the vacuum chamber 110. The third temperature-sensing excitation pad 250 is connected to the pressure-sensing layer 200. The third temperature-sensing excitation pad 250 is located outside the vacuum chamber 110.

[0139] It should be noted that the settings of the first temperature-sensing vibration pad 3321, the second temperature-sensing vibration pad 240, and the third temperature-sensing vibration pad 250 are the same as those of the first pressure-sensing vibration pad 3311, the second pressure-sensing vibration pad 220, and the third pressure-sensing vibration pad 230 in the above embodiment. For details, please refer to the above content, and no limitation is made here.

[0140] In this embodiment, the first pressure-sensing excitation pad 3311 is disposed on the first boss 210 component, and the first temperature-sensing excitation pad 3321 is disposed on the second boss 210 component. The first pressure-sensing excitation pad 3311 and the first temperature-sensing excitation pad 3321 are disposed on different boss 210 components, which helps to isolate the test circuit of the temperature-sensing tuning fork 340 and the tuning fork vibrating beam assembly, and can reduce the error caused by mutual interference between the temperature-sensing tuning fork 340 and the tuning fork vibrating beam assembly, thereby improving the reliability of the resonant pressure sensor.

[0141] refer to Figure 4 As shown, the resonant pressure sensor provided in this embodiment of the invention further includes a guide layer 400. The guide layer 400 and the capping layer 100 are respectively located on both sides of the pressure-sensing layer 200, and a pressure-sensing chamber 410 is formed between the pressure-sensing layer 200 and the guide layer 400. The guide layer 400 is provided with a guide channel 420 communicating with the pressure-sensing chamber 410. The guide channel 420 is used to introduce the fluid to be measured into the pressure-sensing chamber 410, so that the fluid to be measured applies an input force to the pressure-sensing layer 200. In this embodiment, the guide layer 400 and the capping layer 100 are respectively located on both sides of the pressure-sensing layer 200, which can protect the pressure-sensing layer 200 and thus extend the service life of the pressure-sensing layer 200.

[0142] The fluid to be tested can be a gas, a liquid, or a mixture of gas and liquid.

[0143] In this embodiment, the side of the guide layer 400 away from the pressure-sensing layer 200 is used to adhere to the casing or base. When external vibration or impact is transmitted to the side of the guide layer 400 away from the pressure-sensing layer 200, the guide layer 400 can absorb some of the stress and energy generated by the vibration or impact, reducing the impact of vibration or impact on the pressure-sensing layer 200 and improving the sensitivity of detection.

[0144] When the guide layer 400 is bonded to the casing or base, assembly stress is generated. When the material of the casing or base differs from that of the guide layer 400 (i.e., their coefficients of thermal expansion are different), stress and strain can easily occur in the pressure-sensitive layer 200, leading to frequency drift in the tuning fork vibrating beam assembly (vitrifying beam frequency drift refers to the change in the resonant frequency of the tuning fork vibrating beam 311 over time or under environmental conditions; this drift can be caused by various factors, including temperature changes, stress, vibration, and impact). The guide layer 400 effectively absorbs assembly stress and thermal stress, and its good isolation effect ensures the testing performance of the tuning fork vibrating beam assembly.

[0145] refer to Figure 4 As shown, a first isolation groove 430 is provided on the side of the guide layer 400 away from the pressure-sensing layer 200. The first isolation groove 430 can provide primary protection against vibration, impact, assembly stress or thermal stress on the side away from the pressure-sensing layer 200, thereby improving the isolation effect of the guide layer 400.

[0146] refer to Figure 4 As shown, a second isolation groove 440 is provided on the side of the guide layer 400 near the pressure-sensitive layer 200. The second isolation groove 440 can provide primary protection against vibration, impact, assembly stress or thermal stress on the side near the pressure-sensitive layer 200, thereby improving the isolation effect of the guide layer 400.

[0147] Of course, in some embodiments, the guide layer 400 is provided with a first isolation groove 430 and a second isolation groove 440. The first isolation groove 430 is located on the side of the guide layer 400 away from the pressure-sensing layer 200, and the second isolation groove 440 is located on the side closer to the pressure-sensing layer 200. The first isolation groove 430 and the second isolation groove 440 cooperate to achieve a two-stage isolation and blocking effect. Taking the blocking of thermal stress as an example, the first isolation groove 430 can provide a first-level blocking of the thermal stress generated by the external shell; the second isolation groove 440 can provide a second-level blocking of the thermal stress of the external shell. Under harsh mechanical environments such as vibration and impact, the first isolation groove 430 and the second isolation groove 440 can effectively reduce the impact of vibration and impact on the pressure-sensing layer 200, and effectively reduce the impact of external vibration or impact on the pressure-sensing layer 200 and the resonant tuning fork assembly 300.

[0148] Multiple first isolation grooves 430 can be provided to improve the stress isolation effect. Similarly, multiple second isolation grooves 440 can also be provided. The first isolation grooves 430 and second isolation grooves 440 can be staggered to achieve stress isolation at different locations; alternatively, they can be coaxial, achieving stress isolation on the same axis. When multiple first isolation grooves 430 and multiple second isolation grooves 440 are provided, their positions can be either coaxial, staggered, or a portion coaxial while another portion staggered. The arrangement of the first isolation grooves 430 and second isolation grooves 440 can be determined according to actual needs and is not limited here.

[0149] Preferably, refer to Figure 11 As shown, the first isolation groove 430 is an annular groove, and the second isolation groove 440 is also an annular groove. The first isolation groove 430 and the second isolation groove 440 surround the side wall of the guide layer 400. The annular groove can effectively increase the area of ​​the first isolation groove 430 and the second isolation groove 440, thereby increasing the isolation effect.

[0150] A second aspect of the present invention provides a method for manufacturing a resonant pressure sensor, the method comprising the following steps:

[0151] S1. A protrusion 210 is formed on the pressure-sensitive layer 200; wherein, the protrusion 210 can be formed by etching the pressure-sensitive layer 200, and the etching can be wet chemical etching, dry etching, laser etching, etc.

[0152] S2. The resonant tuning fork assembly 300 is disposed on the pressure-sensitive layer 200, wherein the resonant tuning fork assembly 300 is connected to the boss 210;

[0153] In this step, the resonant tuning fork assembly 300 is placed on the pressure-sensitive layer 200, which can be achieved by connecting the first folded beam 321 and the second folded beam 322 to the boss 210.

[0154] When the resonant tuning fork assembly 300 includes a boss docking component, the boss docking component can be connected to the boss 210 through the first glass paste 510. The connection between the boss docking component and the boss 210 is achieved by sintering the first glass paste 510 at a first preset temperature for a first preset time.

[0155] When the sensing layer has a protrusion 210 but no first groove 270, the first preset temperature can be 415-465 degrees Celsius, and the first preset duration can be 10-20 minutes. Preferably, the first preset temperature is 440 degrees Celsius, and the first preset duration is 15 minutes.

[0156] When the sensing layer is provided with a protrusion 210 and a first groove 270, the first preset temperature can be 365-415 degrees Celsius, and the first preset duration can be 10-20 minutes. Preferably, the first preset temperature is 390 degrees Celsius, and the first preset duration is 15 minutes.

[0157] S3. The capping layer 100 is placed on the pressure-sensitive layer 200, wherein the capping layer 100 is connected to the pressure-sensitive layer 200.

[0158] In this step, the capping layer 100 is connected to the pressure-sensitive layer 200 through the second glass slurry 520. The connection between the capping layer 100 and the pressure-sensitive layer 200 is achieved by sintering the second glass slurry 520 at a second preset temperature for a second preset time. The second preset temperature is lower than the first preset temperature.

[0159] When the sensing layer has a protrusion 210 but no first groove 270, the second preset temperature can be 405-455 degrees Celsius, and the second preset duration can be 10-20 minutes. Preferably, the second preset temperature is 430 degrees Celsius, and the second preset duration is 15 minutes.

[0160] When the sensing layer is provided with a protrusion 210 and a first groove 270, the second preset temperature can be 355-405 degrees Celsius, and the second preset duration can be 10-20 minutes. Preferably, the second preset temperature is 380 degrees Celsius, and the second preset duration is 15 minutes.

[0161] The manufacturing method of the resonant pressure sensor provided in the second aspect embodiment of the present invention further includes: disposing the pressure-sensing layer 200 on the guide layer 400.

[0162] In this step, the pressure-sensitive layer 200 is sintered onto the guide layer 400 by the third glass paste 530, and the third glass paste 530 is sintered at a third preset temperature for a third preset time.

[0163] When the sensing layer has a protrusion 210 but no first groove 270, the third preset temperature can be 425-475 degrees Celsius, and the third preset duration can be 10-20 minutes. Preferably, the third preset temperature is 450 degrees Celsius, and the third preset duration is 15 minutes.

[0164] When the sensing layer is provided with a protrusion 210 and a first groove 270, the third preset temperature can be 375-425 degrees Celsius, and the third preset duration can be 10-20 minutes. Preferably, the third preset temperature is 400 degrees Celsius, and the third preset duration is 15 minutes.

[0165] The resonant pressure sensor and its manufacturing method provided in the embodiments of the present invention will be described below.

[0166] (1) The all-quartz sensitive structure is adopted; the pressure-sensing layer 200, the resonant tuning fork assembly 300, the guiding layer 400, the temperature-sensing tuning fork 340 and the capping layer 100 are all made of quartz crystal material, which improves the matching of the thermal expansion coefficients of the materials and solves the temperature drift problem caused by the mismatch of the thermal expansion coefficients of the materials. The pressure-sensing assembly is fabricated using QMEMS technology, which replaces the traditional processing method of processing individual parts, thereby improving the processing efficiency.

[0167] (2) A glass slurry sealing structure with getter is adopted; a glass slurry with a coefficient of thermal expansion matching that of quartz crystal is selected to achieve vacuum sealing sintering of the quartz components (sintering of the resonant tuning fork component 300 and pressure-sensing layer 200, sintering of the capping layer 100 and pressure-sensing layer 200, and sintering of pressure-sensing layer 200 and guiding layer 400), forming vacuum chamber 110 and pressure-sensing chamber 410 respectively, and effectively protecting the electrodes (first excitation electrode 301 and second excitation electrode 341). Among them, magnetron sputtering technology and shielding plate technology are used to prepare a thin film getter layer 120 at the bottom of the cavity 130 of the capping layer 100, and the getter layer 120 is activated by infrared irradiation heating technology to achieve long-term maintenance of high vacuum and ensure that the quartz resonator (i.e., the resonant tuning fork component 300) has a high quality factor.

[0168] (3) A tuning fork vibrating beam 311 scheme with a temperature-sensing tuning fork 340 and a lever multiplier structure; based on the tuning fork vibrating beam assembly, the temperature-sensing tuning fork 340 and the lever multiplier structure are integrated and integrated processing is achieved. Among them, the lever multiplier structure is used to amplify the axial force of the tuning fork vibrating beam 311, improve the force-frequency coefficient of the tuning fork vibrating beam 311, improve the sensitivity of the resonant pressure sensor as a whole, and effectively isolate the influence of external thermal stress on the tuning fork vibrating beam 311, solving the stress isolation problem under high sensitivity conditions. The integrated temperature-sensing tuning fork 340 can accurately reflect the core temperature of the resonant tuning fork assembly 300 (that is, the temperature of the tuning fork vibrating beam 311), improve the temperature compensation effect, and avoid the error caused by the temperature-sensing tuning fork 340 being set separately from the tuning fork vibrating beam assembly and the need for secondary pasting of the temperature-sensing tuning fork 340.

[0169] (4) A pressure-sensitive layer 200 structure with a first groove 270 and a boss 210 is adopted. First, the pressure-sensitive layer 200 structure with the first groove 270 and the boss 210 can transform the pressure-sensitive deformation of the pressure-sensitive layer 200 from the traditional tensile deformation to bending deformation, thereby improving the sensitivity of the pressure-sensitive layer 200. Second, during the assembly process, due to the presence of assembly stress, the over-positioned pressure-sensitive layer 200 may undergo torsional deformation, which the pressure-sensitive layer 200 can effectively absorb. Third, during high and low temperature tests, the thermal stress present in the sensitive structure can cause the pressure-sensitive layer 200 to undergo torsional deformation, which the first groove 270 and the boss 210 can effectively absorb. Fourth, the boss 210 structure can increase the deformation of the pressure-sensitive membrane, thereby improving the sensitivity.

[0170] (5) A two-stage stress isolation scheme is adopted; two-stage stress isolation grooves (i.e., the first isolation groove 430 and the second isolation groove 440) are designed on the guide layer 400. After wafer-level bonding, effective isolation of assembly stress, thermal stress and vibration impact force is achieved. When the resonant pressure sensor is bonded to the T0 tube shell or LCC ceramic tube shell base, the mismatch of the thermal expansion coefficients of the tube shell material and the quartz material (which can also be understood as different thermal expansion coefficients) will lead to the generation of assembly stress. By designing two-stage stress isolation grooves on the guide layer 400, effective isolation of assembly stress is achieved. Under high and low temperature conditions, the mismatch of the thermal expansion coefficients between the tube shell and the resonant pressure sensor can easily lead to the transmission of thermal stress to the resonant pressure sensor, causing stress strain in the pressure sensing layer 200, which in turn causes frequency drift of the tuning fork beam 311. The design of the outer isolation groove (i.e., the first isolation groove 430) provides the first level of protection against the thermal stress generated by the outer shell; the design of the inner stress isolation groove (i.e., the second isolation groove 440) at the bonding position between the guiding layer 400 and the pressure-sensing layer 200 provides the second level of protection against the thermal stress generated by the outer shell. Under harsh mechanical environments such as vibration and impact, the isolation groove can effectively reduce the impact of vibration and impact on the resonant pressure sensor, minimizing the impact of external vibration or impact on the pressure-sensing layer 200 and the resonant tuning fork assembly 300.

[0171] The manufacturing method of the resonant pressure sensor provided in this embodiment of the invention uses a full quartz resonant beam structure with temperature compensation, and the overall structure is as follows: Figure 4 As shown, the entire sensitive structure consists of four layers: a guiding layer 400, a pressure-sensing layer 200, a vibrating beam layer, and a capping layer 100.

[0172] First, the pressure-sensitive layer 200 and the guiding layer 400 are bonded at the wafer level using a glass paste (i.e., the third glass paste 530), with a sintering temperature (third preset temperature) of 425–475 degrees Celsius and a holding time (third preset duration) of 10–20 minutes. Preferably, the bonding temperature is 450 degrees Celsius and the holding time is 15 minutes.

[0173] Secondly, the resonant tuning fork assembly 300 utilizes visual alignment bonding technology, applying a glass paste (i.e., the first glass paste 510) onto two combined layers (pressure-sensitive layer 200 and guiding layer 400) to achieve component bonding and sintering on the wafer. The sintering temperature (first preset temperature) is 415–465 degrees Celsius, and the holding time (first preset duration) is 10–20 minutes. Preferably, the sintering temperature is 440 degrees Celsius, and the holding time is 15 minutes. The vibrating beam electrode and the pressure-sensitive layer 200 electrode are electrically traction-enabled via wafer-level gold wire bonding.

[0174] The visual alignment and patching technology involves using a camera and image processing software to capture images of the resonant tuning fork assembly 300 and the target position (which can be understood as the position of the boss 210). The images are then processed to determine the position, orientation, and other relevant features of the resonant tuning fork assembly 300. Based on the image processing results, the resonant tuning fork assembly 300 is precisely aligned to the target position. Once aligned, the resonant tuning fork assembly 300 is adhered to the boss 210 using a first glass paste 510.

[0175] Finally, the capping layer 100 and the three-layer composite sheet (resonant tuning fork assembly 300, pressure-sensitive layer 200, and guide layer 400) achieve wafer-level vacuum bonding activated by the getter layer 120. The bonding temperature (second preset temperature) is 405–455 degrees Celsius, and the holding time (second preset duration) is 15 minutes. Preferably, the bonding temperature is 430 degrees Celsius, and the holding time is 15 minutes.

[0176] Before sintering the capping layer 100 with the three-layer composite sheet, the getter layer 120 is activated. Activation of the getter layer 120 is achieved using infrared radiation heating technology. Preferably, the getter activation temperature is 500 degrees Celsius, and the activation time is 15 minutes. The getter layer 120 releases a large amount of gas during activation; this step must be performed before sintering the capping layer 100 with the three-layer composite sheet to prevent the gas released by the getter layer 120 from affecting the resonant tuning fork assembly 300.

[0177] The resonant tuning fork assembly 300 with the cap layer 100 removed, as shown below. Figure 6 As shown, the resonant tuning fork assembly 300 includes a tuning fork vibrating beam assembly and a temperature-sensing tuning fork 340. The two electrodes of the temperature-sensing tuning fork 340 (i.e., the second excitation electrode 341) are bonded to the pressure-sensing layer 200 via gold wires (i.e., wires 333). The electrodes of the tuning fork vibrating beam assembly (i.e., the first excitation electrode 301) are bonded to the pressure-sensing layer 200 via gold wires with a diameter of 10–25 μm.

[0178] The structure after removing the capping layer 100, the vibrating beam layer, and the gold wire bonding is as follows: Figure 8 As shown, the device includes a pressure-sensitive layer 200 with a second groove 280 (the second groove 280 is also formed when the pressure-sensitive layer 200 forms a boss 210 by etching), excitation pads on the surface of the pressure-sensitive layer 200, electrode leads 260, quartz bosses 210, and a bonding glass paste ring (this glass paste ring is the second glass paste 520). The functional pads on the surface of the pressure-sensitive layer 200 have a size of 250um*250um, the trace width of the electrode leads 260 is 50um, and the width of the bonding paste ring is 1mm.

[0179] The capping layer 100 uses a 3-inch diameter quartz wafer cut from z0. For example... Figure 13 As shown, the cavity 130 was machined using a wet etching process. A non-evaporable metal thin film getter was sputtered at the bottom of the cavity 130 using a hard shielding process and magnetron sputtering technology. The target material was primarily composed of titanium-zirconium alloy. Among these, [the text abruptly ends here]. Figure 4 and Figure 13 The specific dimensions of the capping layer 100 structure are shown in Table 1.

[0180] Table 1. Dimensional parameters of the capping layer (unit: μm)

[0181] h1 d1 h2 d2 h3 d3 e1 e2 e3 9500 9500 7500 7500 1600 8000 1500 500 1

[0182] The resonant beam layer (i.e., the resonant tuning fork assembly) uses a 3-inch diameter quartz wafer cut from Z0. For example... Figure 7 As shown, the quartz vibrating beam with a temperature-sensing tuning fork 340 and a lever multiplier structure comprises eight parts: a tuning fork vibrating beam 311, tuning fork joint blocks (first tuning fork joint block 312 and second tuning fork joint block 313), tuning fork stress isolation beams (first tuning fork stress isolation beam 314 and second tuning fork stress isolation beam 315), folding beam joint blocks (first folding beam joint block 316 and second folding beam joint block 317), folding beams (first folding beam 321 and second folding beam 322), boss docking components (first boss docking component 331 and second boss docking component 332), a temperature-sensing tuning fork 340, and a counterweight tuning fork 350.

[0183] Each pair of tuning fork vibrating beams 311 operates through horizontal differential mode resonance of two single beams. The two single beams are coupled together through tuning fork nodes. The tuning fork nodes are connected to a single tuning fork stress isolation beam to achieve stress isolation. The four folded beams and the tuning fork vibrating beams 311 form a "rhomboid" composite beam structure in the node area.

[0184] When the pressure-sensitive layer 200 senses pressure input in the normal direction, the deformation of the pressure-sensitive layer 200 causes a change in the relative position between the two bosses 210, which in turn causes a change in the relative position between the boss mating parts, thereby causing the folded beam to undergo tensile and compressive deformation.

[0185] When the relative position of the two boss mating parts increases, the axial compressive stress of the tuning fork vibrating beam 311 increases through the four folding beams, causing a decrease in the resonant frequency of the tuning fork vibrating beam 311. When the relative position of the two boss mating parts decreases, the axial tensile stress of the tuning fork vibrating beam 311 decreases through the four folding beams, causing an increase in the resonant frequency of the tuning fork. The recommended resonant frequency of the tuning fork vibrating beam 311 is 34kHz to 36kHz. When the pressure-sensitive layer 200 includes only the boss 210, the recommended quality factor Q is 8000 to 10000; when the pressure-sensitive layer 200 includes the boss 210 and the first groove 270, the recommended quality factor Q is 12000 to 19000.

[0186] The integrated temperature-sensing tuning fork 340 adopts a single-end fixed tuning fork structure. The two fork teeth use planar differential mode as the working mode, with a recommended resonant frequency of 120kHz to 130kHz. The temperature model of the temperature-sensing tuning fork 340 in planar differential mode is as follows:

[0187] Here, Δf = f - f0; ΔT = T - T0; f and f0 are the resonant frequencies of the thermometric tuning fork 340 at temperatures T and T0 (T0 = 25℃), respectively. α0, α1, α2, and α3 are the 0th to 3rd order temperature coefficients, respectively. The thermometric tuning fork 340 uses a Z0-cut quartz crystal, making α2 and α3 close to zero, with a first-order temperature coefficient α1 of 35–45 ppm / ℃. The temperature measurement range is -80℃ to 230℃, and the temperature measurement accuracy can reach 0.02℃.

[0188] To improve the symmetry of the resonant pressure sensor, a counterweight tuning fork 350 is added. The counterweight tuning fork 350 has the same structural dimensions as the temperature-sensing tuning fork 340; therefore, the vibrating beam has one temperature-sensing tuning fork 340 and one counterweight tuning fork 350. The thickness of the temperature-sensing tuning fork 340, the counterweight tuning fork 350, the folded beam, and the vibrating beam is h0. Preferably, the folded beam makes an angle θ = 60 degrees with the horizontal direction. Figure 7 The recommended structural dimensions of the resonant tuning fork assembly are shown in Table 2.

[0189] Table 2. Dimensional parameters of the quartz vibrating beam with temperature-measuring tuning fork (unit: μm)

[0190] Structural parameters L1 L2 L3 L4 L5 L6 L7 L8 L9 L10 W0 h0 Vibrating beam 2000 300 350 500 35 600 600 100 100 400 50 80 Structural parameters W1 W2 W3 W4 W5 W6 W7 W8 W9 W10 W11 W12 Vibrating beam 30 500 60 800 60 500 1000 300 500 100 55 55

[0191] The pressure-sensitive layer 200 uses a 3-inch diameter quartz wafer cut from z0. The structure is as follows: Figure 8 As shown, the sheet thickness is 220µm to 1920µm, and the key structure includes a pressure-sensitive layer 200, a quartz boss 210, and a gold-plated electrode layer 290 (including excitation pads and electrode wires 333 connecting the excitation pads). When the pressure-sensitive layer 200 includes the boss 210 and the first groove 270, the depth of the first groove 270 and the height of the boss 210 are equal due to the simultaneous wet etching on opposite sides of the pressure-sensitive film. The thickness of the pressure-sensitive layer 200 is determined by the range of the resonant pressure sensor; the designed thickness of the pressure-sensitive layer 200 is 100µm to 1800µm, and the range of the resonant pressure sensor is 100kPa to 50.1MPa. The height of the quartz boss 210 is 120µm to 240µm, preferably 120µm. The quartz boss 210 here amplifies the strain of the pressure-sensitive layer 200, thereby improving the pressure sensitivity of the pressure-sensitive layer 200. The gold-plated electrode layer 290 is a magnetron sputtered chromium base film. The chromium base film can provide a stable connection for the connection between the gold-plated electrode layer 290 and the pressure-sensitive layer 200, and then the gold-plated electrode layer is magnetron sputtered.

[0192] Combination Figure 8 and Figure 9 When the pressure-sensitive layer 200 only has the boss 210 and does not include the first groove 270, the recommended dimensions of the pressure-sensitive layer 200 are shown in Table 3. Taking the height of the quartz boss 210 as 120um as an example, the thickness of the pressure-sensitive layer 200 under different ranges and the thickness of the pressure-sensitive layer 200 at the position of the boss 210 after etching to form the boss 210 are shown in Table 4.

[0193] Table 3. Dimensional parameters of the quartz pressure-sensitive layer (unit: μm)

[0194] h7 d7 h8 d8 h9 d9 h10 d10 d11 d12 e7 e8 e9 10000 10000 7000 7000 600 1000 600 500 400 1000 400 0.5 100

[0195] Table 4. Pressure-sensitive layer and its thickness (µm) under different measurement ranges

[0196] range 100kPa 200kPa 500kPa 1.7MPa 3.6MPa 50.1MPa Pressure-sensitive layer thickness e7 220 270 370 520 620 1920 Thickness of pressure-sensitive layer at the protrusion: e9 100 150 250 400 500 1800

[0197] Combination Figure 8 and Figure 10 When the pressure-sensitive layer 200 is provided with both the boss 210 and the first groove 270, the recommended dimensions of the pressure-sensitive layer 200 are shown in Table 5. Taking the height of the quartz boss 210 as 120um as an example, the thickness of the pressure-sensitive layer 200 under different ranges and the thickness of the pressure-sensitive layer 200 at the position of the boss 210 after etching to form the boss 210 are shown in Table 6.

[0198] Table 5. Dimensional parameters of the quartz pressure-sensitive layer (unit: μm)

[0199] h7 d7 h8 d8 h9 d9 h10 d10 10000 10000 7000 7000 600 1000 600 500 d11 d12 e7 e8 e9 e10 e11 e12 400 1000 400 0.5 100 100 1000 7000

[0200] Table 6. Thickness parameters (µm) of pressure-sensitive layer and pressure-sensitive membrane under different measurement ranges.

[0201] range 100kPa 200kPa 500kPa 1.7MPa 3.6MPa 50.1MPa Pressure-sensitive layer thickness e7 220 270 370 520 620 1920 The thickness of the bottom layer is e9 100 150 250 400 500 1800 The thickness of the bottom layer is e10 100 150 250 400 500 1800 Thickness e13 100 150 250 400 500 1800

[0202] The guide layer 400 uses a 3-inch diameter quartz wafer cut from z0, with a structure as follows: Figure 12 As shown, annular stress isolation grooves are machined on the upper and lower surfaces of the guide layer 400 using wet etching, and guide channels 420 are machined using ultrasonic drilling technology. Figure 11 and Figure 12 The specific dimensions are shown in Table 7.

[0203] Table 7. Dimensional parameters of the quartz gas-conducting layer (unit: μm)

[0204] h4 d4 h5 d5 h6 d6 e4 e5 e6 10000 10000 7000 7000 1600 8000 500 500 1200

[0205] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, and not to limit them; although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some of the technical features; and these modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the spirit and scope of the technical solutions of the embodiments of the present invention.

Claims

1. A resonant pressure sensor, characterized in that, include: Cap layer; A pressure-sensitive layer is used to sense changes in input force. The pressure-sensitive layer is connected to the capping layer, and a vacuum chamber is formed between the capping layer and the pressure-sensitive layer. The pressure-sensitive layer is provided with at least two protrusions and at least two first grooves. The protrusions and the first grooves are arranged in a one-to-one correspondence. The protrusions are located in the vacuum chamber, and the first grooves are arranged on the side of the pressure-sensitive layer away from the capping layer. The protrusions and the first grooves are arranged sequentially along the direction away from the input force. A resonant tuning fork assembly is disposed within the vacuum chamber, with at least two protrusions disposed on opposite sides of the resonant tuning fork assembly. The resonant tuning fork assembly is connected to the protrusions and is used to connect to a first external circuit. Two protrusions are provided, and two first grooves are provided. The two protrusions are arranged opposite each other on both sides of the input force, and the input direction of the input force is perpendicular to the line connecting the two protrusions. The resonant tuning fork assembly includes a tuning fork vibrating beam assembly, a first folded beam, and a second folded beam. One end of the tuning fork vibrating beam assembly is connected to the boss through the first folded beam, and the other end of the tuning fork vibrating beam assembly is connected to the boss through the second folded beam. The first folded beam, the second folded beam, and the tuning fork vibrating beam assembly are suspended in mid-air. The resonant tuning fork assembly further includes a boss docking component. At least one of the first folded beam and the second folded beam is connected to the boss through the boss docking component. Two bosses are provided, and two boss docking components are provided. The bosses and boss docking components are provided in a one-to-one correspondence. The tuning fork vibrating beam assembly is disposed between the two boss docking components.

2. The resonant pressure sensor according to claim 1, characterized in that, The pressure-sensitive layer has a second groove on the side facing the vacuum chamber, and the boss is disposed in the second groove. The first groove and the second groove are spaced apart.

3. The resonant pressure sensor according to claim 2, characterized in that, The first sidewall of the first groove is parallel to the second sidewall of the second groove, which is adjacent to the first groove. The distance between the first sidewall and the second sidewall is greater than or equal to 100 micrometers and less than or equal to 1800 micrometers.

4. The resonant pressure sensor according to claim 2, characterized in that, The depth of the first groove is the same as the height of the boss, and / or the depth of the second groove is the same as the height of the boss.

5. The resonant pressure sensor according to claim 2, characterized in that, The thickness of the pressure-sensitive layer is greater than or equal to 220 micrometers and less than or equal to 1920 micrometers, and the height of the boss is greater than or equal to 120 micrometers and less than or equal to 240 micrometers.

6. The resonant pressure sensor according to claim 1, characterized in that, The distance between the two first grooves is greater than or equal to 5000 micrometers and less than or equal to 7000 micrometers, and the length of the opening end of the first groove is greater than or equal to 1000 micrometers and less than or equal to 2000 micrometers.

7. A method for manufacturing a resonant pressure sensor according to any one of claims 1 to 6, characterized in that, include: The protrusion is formed on the pressure-sensitive layer; The resonant tuning fork assembly is disposed on the pressure-sensitive layer, wherein the resonant tuning fork assembly is connected to the boss; The capping layer is disposed on the pressure-sensitive layer, wherein the capping layer is connected to the pressure-sensitive layer.

Images