High-precision resonance ball type pressure and temperature integrated sensor

Abstract

The invention relates to a high-precision resonance ball type pressure and temperature integrated sensor, which is characterized in that a resonance ball and a resonance ball fixed support structure are integrally processed, the outer wall of the resonance ball is provided with a resonance ball surface electrode, and the inner wall of a spherical groove on a back cavity structure is provided with a back cavity structure surface electrode; the resonance ball clamped structure and the back cavity structure realize vacuum sealing through a bonding layer, an absolute pressure measurement vacuum cavity is formed between the resonance ball and the spherical groove after sealing, and surface electrodes of the resonance ball are in one-to-one correspondence with surface electrodes of the back cavity structure; a temperature measuring element is arranged on the outer wall of the resonance ball and used for sensing the temperature of the resonance ball in situ, and in-situ temperature error compensation of pressure measurement is achieved. According to the invention, real-time synchronous measurement of pressure and temperature is realized, and in-situ temperature compensation of pressure measurement is also realized, so that the measurement precision, long-term stability and temperature following performance of the pressure sensor are improved.

Description

Technical Field

[0001] This invention belongs to the field of sensor design technology and relates to a high-precision resonant spherical pressure and temperature integrated sensor. Background Technology

[0002] With the technological advancements in fields such as aviation, aerospace, oceanography, and meteorology, there are higher requirements for the accuracy and long-term stability of pressure and temperature measurements.

[0003] Currently, high-precision resonant ball pressure sensors use a resonant ball as the mechanical sensing element for pressure measurement, offering advantages such as high measurement accuracy and good long-term stability. However, because current temperature error compensation uses discrete temperature sensing elements, with the temperature sensing element and the resonant ball located in different positions, the accuracy and tracking of temperature compensation are poor, affecting measurement accuracy, long-term stability, and temperature response. Summary of the Invention

[0004] The technical problem solved by this invention is to overcome the shortcomings of the prior art and propose a high-precision resonant spherical pressure and temperature integrated sensor.

[0005] The solution of the present invention is: A high-precision resonant sphere integrated pressure and temperature sensor includes a resonant sphere, a resonant sphere fixed support structure, a resonant sphere surface electrode, a back cavity structure, a back cavity structure surface electrode, a bonding layer, and a temperature sensing element. The resonant sphere and the resonant sphere fixed support structure are integrally processed. The resonant sphere fixed support structure not only supports the resonant sphere but also forms a sealed connection structure with the resonant sphere. The outer wall of the resonant sphere is designed with a resonant sphere surface electrode, and the back cavity structure is designed with a spherical groove. The inner wall of the spherical groove is designed with a back cavity structure surface electrode. The resonant sphere fixed support structure and the back cavity structure achieve vacuum sealing through a bonding layer. After sealing, an absolute pressure measurement vacuum cavity is formed between the resonant sphere and the spherical groove. The resonant sphere surface electrode and the back cavity structure surface electrode correspond one-to-one. The resonant sphere surface electrode and the back cavity structure surface electrode are connected to the outside of the vacuum cavity for encapsulating electrical leads. Temperature sensing elements are arranged on the outer wall of the resonant sphere to sense the temperature of the resonant sphere in situ, thereby achieving in-situ temperature error compensation for pressure measurement.

[0006] Preferably, the resonant sphere, the resonant sphere fixed support structure, and the back cavity structure are made of the same material, namely glass or fused silica.

[0007] Preferably, the spherical groove of the back cavity structure is processed by wet etching process or spherical grinding and polishing process.

[0008] Preferably, the resonant sphere is blown onto the fixed support structure of the resonant sphere using a blow molding process.

[0009] Preferably, a hard mask combined with a side electrode deposition process is used on the outer wall of the resonant sphere to obtain the surface electrode and temperature sensing element of the resonant sphere.

[0010] Preferably, a hard mask combined with a side electrode deposition process is used on the inner wall of the spherical groove to obtain the surface electrode of the back cavity structure.

[0011] Preferably, the surface electrodes of the resonant sphere are an even number of evenly distributed electrodes; the surface electrodes of the resonant sphere correspond one-to-one with the surface electrodes of the back cavity structure, forming the driving electrode and the detection electrode of the resonant sphere; the driving electrode is used to drive the resonant sphere to the corresponding vibration mode, and the detection electrode is used to detect the change of the frequency of the resonant sphere under different pressures, thereby realizing the pressure measurement.

[0012] The advantages of this invention compared to the prior art are: (1) High measurement accuracy and resolution. The resonant sphere of this invention is made of materials such as glass or fused silica with a low coefficient of expansion, which has the advantages of simple structure and good consistency. Its Q value can reach hundreds of thousands to millions, which is more than an order of magnitude higher than the Q value of existing resonant pressure sensors. Moreover, since the pressure medium acts directly on the surface of the resonant sphere, no additional mechanical transmission structure is required, which can greatly reduce the hysteresis and repeatability error of the sensor. The above two advantages effectively ensure that the pressure sensor has extremely high measurement accuracy and resolution.

[0013] (2) Good long-term stability. The resonant sphere and its fixed support are made of homogeneous low expansion coefficient glass or fused silica, which can eliminate residual stress and thermal stress in the structure and effectively ensure the long-term stability of the resonant sphere pressure sensor.

[0014] (3) In-situ temperature compensation. The present invention fabricates the temperature sensing element on the surface of the resonant sphere, senses the temperature of the resonant sphere in situ, realizes in-situ temperature error compensation, avoids the problem of real-time temperature inconsistency caused by the temperature sensing element and the pressure measuring resonant sphere being in different positions, improves the accuracy and tracking of temperature compensation, and realizes integrated pressure and temperature sensing and measurement. Attached Figure Description

[0015] Figure 1 Structure diagram of a high-precision resonant sphere integrated pressure and temperature sensor; Figure 2 Resonant sphere structure and surface electrode distribution diagram; Figure 3 Diagram of back cavity structure and surface electrode distribution. Detailed Implementation

[0016] The invention will now be further described with reference to the accompanying drawings.

[0017] like Figure 1As shown, the present invention provides a high-precision resonant sphere pressure and temperature integrated sensor, comprising a resonant sphere 1, a resonant sphere fixed support structure 2, a resonant sphere surface electrode 3, a back cavity structure 4, a back cavity structure surface electrode 5, a bonding layer 6, and a temperature sensing element 7.

[0018] The resonant sphere 1 and the resonant sphere fixed support structure 2 are integrally manufactured from the same material, both fixing the resonant sphere 1 and forming a sealed connection structure to realize the pressure sensing structure. The outer wall of the resonant sphere 1 is designed with a resonant sphere surface electrode 3, and the back cavity structure 4 is designed with a spherical groove. The inner wall of the spherical groove is designed with a back cavity structure surface electrode 5, and the resonant sphere surface electrode 3 and the back cavity structure surface electrode 5 correspond one-to-one. The resonant sphere fixed support structure 2 and the back cavity structure 4 achieve vacuum sealing through filler bonding and other methods to form an absolute pressure measurement vacuum cavity, and connect the resonant sphere surface electrode 3 and the back cavity structure surface electrode 5 to the outside of the vacuum cavity for encapsulating electrical leads. Figure 3 This is a diagram showing the back cavity structure and surface electrode distribution.

[0019] The resonant sphere surface electrodes 3 are arranged in even-numbered configurations, such as 4, 6, or 8 electrodes. The back cavity structure surface electrodes 5 are also arranged in even-numbered configurations, such as 4, 6, or 8 electrodes. The resonant sphere surface electrodes and the back cavity structure surface electrodes are arranged in pairs on the structure surface, forming the driving electrode and the detection electrode of the resonant sphere. The driving electrode is used to drive the resonant sphere to the corresponding vibration mode (frequency), and the detection electrode is used to detect the change in the frequency of the resonant sphere under different pressures, thereby realizing pressure measurement.

[0020] The temperature sensing element 7 is located on the surface of the resonant sphere and is used to sense the temperature of the resonant sphere in situ. This not only achieves in-situ temperature error compensation for pressure measurement, but also enables direct temperature measurement.

[0021] The resonant sphere 1 and the resonant sphere fixed support structure 2 of the present invention are integrally formed from glass or fused silica material. The structural diagrams of the resonant sphere 1 and the resonant sphere fixed support structure 2 of the present invention are shown below. Figure 2 As shown. To meet the requirements of different pressure ranges, a blow molding process is used to blow the resonant sphere 1 onto the glass or quartz resonant sphere fixed structure 2. A hard mask combined with side electrode deposition technology is used to obtain the surface electrode pattern 3 and the temperature sensing element 7. The back cavity structure 4 uses the same material as the resonant sphere 1 and the resonant sphere fixed structure 2, with the spherical grooves processed using wet etching or spherical grinding and polishing. A vacuum filler bonding process is used to bond the resonant sphere fixed structure 2 and the back cavity structure 4, forming a rigid structural connection and a vacuum absolute pressure reference cavity, and leading the internal electrodes to the outside for easy encapsulation. One side of the resonant sphere 1 senses the zero standard pressure, and the other side senses the measured environmental pressure, thus achieving absolute pressure measurement. A hard mask combined with side electrode deposition technology is used to obtain the surface electrode pattern 5.

[0022] In this invention, the output signal of the resonant sphere is a function of pressure and temperature, and the temperature sensing element is a function of temperature, which can be expressed as: (1) f p The resonant frequencies of the resonant spheres under different pressures P and temperatures T; f T The output of the temperature sensing element at different temperatures T.

[0023] A polynomial compensation algorithm is used to achieve high-precision temperature compensation of the pressure signal, thereby improving the accuracy of the high-resonance ball pressure sensor. The core of this method lies in constructing a polynomial through fitting coefficients to accurately describe the actual pressure output relationship. A polynomial algorithm with pressure fitting order i and temperature fitting order j is used, as shown in equation (2). This method has high flexibility and accuracy, enabling the sensor to provide accurate pressure values ​​under various pressure and temperature conditions. The formula is as follows: (2) k ij The fitting coefficients are denoted as .

[0024] Under different temperature and pressure conditions, the high-precision resonant ball pressure and temperature integrated sensor was calibrated, and four sets of calibration data were obtained: standard pressure value, standard temperature value, pressure measurement unit output value, and temperature measurement unit output value. The fitting coefficient was then calculated using software.

[0025] This invention relates to a high-precision resonant spherical pressure and temperature integrated sensor, which enables real-time synchronous measurement of pressure and temperature, as well as in-situ temperature compensation for pressure measurement, thereby improving the measurement accuracy, long-term stability, and temperature tracking performance of the pressure sensor.

[0026] The contents not described in detail in this application specification are common knowledge to those skilled in the art.

Claims

1. A high-precision resonant spherical pressure and temperature integrated sensor, characterized in that: It includes a resonant sphere (1), a resonant sphere fixed structure (2), a resonant sphere surface electrode (3), a back cavity structure (4), a back cavity structure surface electrode (5), a bonding layer (6), and a temperature sensing element (7). The resonant sphere (1) and the resonant sphere fixed support structure (2) are integrally processed. The resonant sphere fixed support structure not only supports the resonant sphere (1) but also forms a sealed connection structure with the resonant sphere. The outer wall of the resonant sphere (1) is designed with a resonant sphere surface electrode (3), and the back cavity structure (4) is designed with a spherical groove. The inner wall of the spherical groove is designed with a back cavity structure surface electrode (5). The resonant sphere fixed support structure (2) and the back cavity structure (4) are vacuum sealed through a bonding layer (6). After sealing, an absolute pressure measurement vacuum cavity is formed between the resonant sphere and the spherical groove. The resonant sphere surface electrode (3) and the back cavity structure surface electrode (5) correspond one-to-one. The resonant sphere surface electrode (3) and the back cavity structure surface electrode (5) are connected to the outside of the vacuum cavity for encapsulating electrical leads. Temperature sensing elements (7) are arranged on the outer wall of the resonant sphere to sense the temperature of the resonant sphere in situ and realize in situ temperature error compensation for pressure measurement.

2. The high-precision resonant spherical pressure-temperature integrated sensor according to claim 1, characterized in that: The resonant sphere, the resonant sphere fixed structure, and the back cavity structure are all made of the same material, which is glass or fused silica.

3. The high-precision resonant spherical pressure-temperature integrated sensor according to claim 1, characterized in that: The spherical grooves of the back cavity structure are processed using wet etching or spherical grinding and polishing processes.

4. The high-precision resonant spherical pressure-temperature integrated sensor according to claim 1, characterized in that: The resonant sphere is blown onto the fixed support structure of the resonant sphere using a blow molding process.

5. A high-precision resonant spherical pressure-temperature integrated sensor according to claim 1, characterized in that: On the outer wall of the resonant sphere, a hard mask combined with a side electrode deposition process is used to obtain the surface electrodes and temperature sensing elements of the resonant sphere.

6. The high-precision resonant spherical pressure-temperature integrated sensor according to claim 1, characterized in that: On the inner wall of the spherical groove, a hard mask combined with a side electrode deposition process is used to obtain the surface electrode of the back cavity structure.

7. A high-precision resonant spherical pressure-temperature integrated sensor according to claim 1, characterized in that: The surface electrodes of the resonant sphere are an even number of evenly distributed electrodes; The surface electrodes of the resonant sphere correspond one-to-one with the surface electrodes of the back cavity structure, forming the driving electrode and the detection electrode of the resonant sphere; The driving electrode is used to drive the resonant ball to the corresponding vibration mode, and the detection electrode is used to detect the change in the frequency of the resonant ball under different pressures, thereby realizing the pressure measurement.

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