Wide-range pressure sensor and manufacturing method thereof

Abstract

The invention provides a wide-range pressure sensor and a manufacturing method thereof. The wide-range pressure sensor comprises a base, a shell, a pressure sensing film and an upper polar plate. The pressure sensing film and the upper pole plate are both located in the shell. The base is mounted at the bottom of the shell and is provided with a gas inlet, so that detected gas can enter the shell; the pressure sensing film is arranged above the base, the upper polar plate is arranged above the pressure sensing film, and a parallel plate capacitor is formed between the upper polar plate and the pressure sensing film. A plurality of electrodes with different areas or different shapes are arranged on the pressure sensing film, and grooves corresponding to the electrodes are formed in the side, facing the pressure sensing film, of the upper electrode plate. The electrodes with different areas or shapes are designed on the pressure sensing film, and a groove is formed in the upper electrode plate, so that the measurement of wide-range gas pressure can be realized. The design of different electrodes and slots enables the sensor to respond to capacitance changes in different pressure ranges, thereby providing a wider measurement range.

Description

Technical Field

[0001] The present invention relates to the field of sensor technology, and in particular to a wide-range pressure sensor and a manufacturing method thereof. Background Art

[0002] Pressure measurement sensors are widely used in semiconductor process equipment, including the measurement of vacuum degree, pressure of various single gases, pressure of mixed gases, etc., and their importance in the field of semiconductor manufacturing is becoming increasingly prominent. Their accuracy and range directly affect the performance of related semiconductor equipment and the accuracy of test results. With the advancement of electronic technology and semiconductor equipment technology, higher requirements are placed on the accuracy and efficiency of pressure measurement sensors. The pressure sensors used in the traditional semiconductor field have a single design of sensitive elements. For example, the shape, area and distance between electrodes of thin-film capacitive pressure sensors are often fixed, resulting in a narrow measurement range and unable to cover a wide range from high vacuum to atmospheric pressure, which limits their comprehensive application in instrumentation operations. Summary of the invention

[0003] The present invention provides a wide-range pressure sensor and a manufacturing method thereof, which are used to solve the defect of narrow measurement range of pressure sensors in the prior art and realize gas pressure measurement within a wide range. The technical solution proposed by the present invention is as follows: In a first aspect, the present invention provides a wide-range pressure sensor, comprising: a base, a housing, a pressure-sensitive membrane and an upper electrode plate; The pressure-sensitive film and the upper electrode plate are both located in the shell; The base is mounted on the bottom of the shell and is provided with an air inlet so that the measured gas can enter the shell; The pressure-sensitive film is arranged above the base, and the upper electrode plate is arranged above the pressure-sensitive film to form a parallel plate capacitor between the upper electrode plate and the pressure-sensitive film; A plurality of electrodes with different areas or shapes are arranged on the pressure-sensitive film, and a groove corresponding to the electrodes is arranged on a side of the upper electrode plate facing the pressure-sensitive film.

[0004] Optionally, the wide-range pressure sensor further includes an air-conducting layer, and the air-conducting layer is arranged between the pressure-sensitive film and the base.

[0005] Optionally, the depths of the plurality of grooves arranged on the upper electrode plate are different.

[0006] Optionally, the depth of the groove is 10 microns-30 microns.

[0007] Optionally, the shell is provided with a clamping structure, and the shell is pressed onto the upper plate through the clamping structure.

[0008] Optionally, the pressure-sensitive film divides the internal space of the shell into a vacuum space and a measured space; wherein the area between the pressure-sensitive film and the upper electrode plate forms the vacuum space, and the area between the air inlet and the pressure-sensitive film forms the measured space.

[0009] Optionally, the pressure-sensitive film is made of quartz, metal material, Inconel alloy, sapphire or diamond.

[0010] Optionally, the upper electrode plate, the gas conducting layer and the pressure-sensitive film are made of the same material.

[0011] In a second aspect, the present invention further provides a method for manufacturing the wide-range pressure sensor, the method comprising: Installing a shell on the base and reserving an air inlet; Arranging a plurality of electrodes with different areas or shapes on the pressure-sensitive film; forming a plurality of grooves on the upper electrode plate corresponding to the electrodes on the pressure-sensitive film; Disposing the upper electrode plate in the housing; The pressure-sensitive film is arranged in the housing and below the upper electrode plate.

[0012] Optionally, the method further comprises: An air guide layer is arranged between the pressure-sensitive film and the base.

[0013] Based on the above technical solution, the beneficial effects of the present invention compared with the prior art are as follows: The wide-range pressure sensor and its manufacturing method provided by the present invention can realize the measurement of a wide range of gas pressure by designing electrodes of different areas or shapes on the pressure-sensitive membrane and slotting the upper electrode plate. The design of different electrodes and slots enables the sensor to respond to capacitance changes within different pressure ranges, thereby providing a wider measurement range. The wide-range capability of the pressure sensor makes it suitable for a variety of different application scenarios, including laboratories, industrial process control, semiconductor manufacturing, etc. It can meet the pressure measurement needs in different environments without the need to replace different sensors.

[0014] Other features and advantages of the present invention will be described in the following description, and partly become apparent from the description, or understood by practicing the present invention. The purpose and other advantages of the present invention are realized and obtained by the structures particularly pointed out in the description, claims and drawings.

[0015] In order to make the above-mentioned objects, features and advantages of the present invention more obvious and easy to understand, preferred embodiments are given below and described in detail with reference to the accompanying drawings. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] In order to more clearly illustrate the technical solutions in the present invention or the prior art, the following briefly introduces the drawings required for use in the embodiments or the description of the prior art. Obviously, the drawings described below are some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative work.

[0017] Figure 1 It is a structural schematic diagram of the wide-range pressure sensor provided by the present invention.

[0018] Figure 2 It is a schematic structural diagram of the pressure-sensitive film provided by the present invention.

[0019] Figure 3 It is a structural schematic diagram of the upper electrode plate provided by the present invention.

[0020] Reference numerals: 1. Shell; 2. Compression structure; 3. Upper plate; 4. Pressure-sensitive membrane; 5. Gas-conducting layer; 6. Base; 7. Electrode; 8. Groove. DETAILED DESCRIPTION

[0021] In order to make the purpose, technical solution and advantages of the present invention clearer, the technical solution of the present invention will be clearly and completely described below in conjunction with the drawings of the present invention. Obviously, the described embodiments are part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0022] Combine the following Figure 1-Figure 3 A wide range pressure sensor of the present invention is described.

[0023] Reference Figure 1 As shown, the wide range pressure sensor covers a measurement range of 1×10 5 The gas vacuum pressure can reach 1 Pa. The sensor comprises the following: a housing 1, an upper plate 3, a pressure-sensitive film 4 and a base 6. These components work together to achieve accurate measurement of the pressure of the gas being measured.

[0024] The base 6 is installed at the bottom of the shell 1 and is the supporting structure of the sensor. An air inlet is provided on the base 6 so that the gas to be measured can enter the shell 1. The shell 1 is a sealed space for accommodating core components such as a pressure-sensitive membrane 4 and an upper electrode plate 3. The shell 1 protects the internal components from interference from the external environment. The pressure-sensitive membrane 4 is arranged above the base 6 and is a key component in the sensor. It can sense the pressure of the gas to be measured and convert it into a change in capacitance. The upper electrode plate 3 is arranged above the pressure-sensitive membrane 4, and a parallel plate capacitor is formed between the pressure-sensitive membrane 4 and the upper electrode plate 3.

[0025] The pressure-sensitive film 4 is provided with a plurality of electrodes 7 of different areas or shapes, and the upper plate 3 is provided with a groove 8 corresponding to the electrode 7 on the side facing the pressure-sensitive film 4. The shape of the groove 8 corresponds to the shape of the electrode 7 on the pressure-sensitive film 4 to ensure that when the pressure-sensitive film 4 is deformed, the capacitance value between the upper plate 3 and the pressure-sensitive film 4 can be affected to the maximum extent. The layout of the groove 8 is designed according to the measurement range and accuracy requirements of the sensor to ensure that the sensor can cover the required measurement range and provide accurate measurement results. The production of the groove 8 can adopt advanced micro-nano processing technology, such as photolithography, etching, etc., to ensure that the depth, shape and layout of the groove 8 can meet the design requirements. At the same time, the materials of the upper plate 3 and the pressure-sensitive film 4 also need to have good conductivity, mechanical strength and stability to ensure the long-term stable operation of the sensor. The depth of the groove 8 can be designed according to the gas pressure measurement range, and can be in the range of 10 microns to 30 microns.

[0026] In terms of shape, especially the pressure-sensitive film 4 and the upper electrode plate 3, the capacitance value is changed by using the area of ​​the electrode 7 on the pressure-sensitive film 4 and the depth of the groove 8 on the upper electrode plate 3, thereby realizing the measurement of gas pressure. The pressure-sensitive film 4 is a material that can deform with changes in external pressure. Figure 2 As shown, four electrodes 7 of different diameters are plated thereon. The areas of these electrodes 7 are different and can be designed as square, ring or circle as needed. The number and shape of the electrodes 7 determine the accuracy and range of the capacitance measurement. The number and shape of the electrodes 7 can be set according to the actual measurement needs. The number can be 2-4 and the shape can be square, ring, circle, etc. Figure 3 As shown, the upper electrode plate 3 corresponds to the pressure-sensitive film 4, and the number and shape of the grooves thereon are the same as those of the electrode 7 on the pressure-sensitive film 4. The depth of the groove 8 can be designed according to the gas pressure measurement range, and can be between 10-30 microns. Taking the setting of four electrodes 7 as an example, the diameters of the four electrodes 7 and the depths of the corresponding grooves 8 are: the diameter of the electrode 7 is 8mm, the depth of the corresponding groove 8 is 0.02mm, the diameter of the electrode 7 is 6mm, the depth of the corresponding groove 8 is 0.025mm, the diameter of the electrode 7 is 4mm, the depth of the corresponding groove 8 is 0.03mm, the diameter of the electrode 7 is 9mm, and the depth of the groove 8 is 0.015. The pressures that can be measured are 10torr, 100torr, 1000torr, and 1torr, respectively.

[0027] The wide-range pressure sensor of the present invention works based on the capacitive measurement principle, that is, when the distance between the pressure-sensitive film 4 and the upper plate 3 changes, the capacitance value of the capacitor formed between them will also change. By measuring the change in this capacitance value, the pressure acting on the pressure-sensitive film 4 can be indirectly measured. Electrodes 7 of different areas or shapes arranged on the pressure-sensitive film 4 can be regarded as different capacitor plates. The groove 8 corresponding to the electrode 7 arranged on the upper plate 3 ensures that when the pressure-sensitive film 4 is deformed, the capacitance value between the upper plate 3 and the pressure-sensitive film 4 can undergo significant and measurable changes.

[0028] By setting the area or shape of the electrode 7 to be different, the initial capacitance value of the formed capacitor will be different. When the same pressure acts on the pressure-sensitive membrane 4, the electrodes 7 of different areas or shapes will produce different deformations, thereby producing different changes in capacitance values. By measuring the changes in these capacitance values ​​and combining the area or shape information of the electrode 7, accurate measurement of different pressure magnitudes can be achieved. The present invention combines multiple electrodes 7 of different areas or shapes with multiple corresponding grooves 8 to form a complex measurement system. This system can cover a wider pressure measurement range and provide higher measurement accuracy within different pressure ranges.

[0029] When the measured gas enters the housing 1 through the air inlet on the base 6, it acts on the pressure-sensitive membrane 4. The pressure-sensitive membrane 4 will be deformed after being subjected to pressure, thereby changing the capacitance value of the parallel plate capacitor formed between it and the upper plate 3. Since a plurality of electrodes 7 of different areas or shapes are provided on the pressure-sensitive membrane 4, the pressure of the measured gas can be accurately calculated by measuring the change in capacitance value. Specifically, when the pressure-sensitive membrane 4 is subjected to pressure, it will move upward and the gap between it and the upper plate 3 will decrease, resulting in an increase in capacitance value. On the contrary, when the pressure decreases, the pressure-sensitive membrane 4 will move downward and the gap between it and the upper plate 3 will increase, resulting in a decrease in capacitance value. By measuring the change in capacitance value, accurate measurement of the pressure of the measured gas can be achieved.

[0030] The present invention can cover a wider pressure measurement range through the combined design of multiple electrodes 7 and multiple slots 8, meeting the needs of more application scenarios. The sensor can be customized according to different application requirements, such as adjusting the area, shape of the electrode 7 or the parameters of the slot 8, to adapt to different measurement environments and requirements. Moreover, by accurately designing the area, shape of the electrode 7 and the parameters of the slot 8, the sensor can have higher measurement accuracy within different pressure ranges.

[0031] Traditional pressure sensors require multiple sensors with different ranges to meet the measurement requirements of different pressure ranges. The wide-range pressure sensor provided by the present invention can achieve a larger range of measurements on one sensor. Only one pressure sensor needs to be installed to cover multiple pressure measurement points, thereby saving installation space and cost. Since the sensor has the characteristics of a wide range, it can be applied to a variety of application scenarios. Whether it is a high-pressure or low-pressure environment, the sensor can provide accurate measurement results. This greatly broadens the application range of the sensor, making it have broad application prospects in the fields of industrial automation, environmental monitoring, etc. Moreover, the internal structure of the sensor is simple and stable, and is not easily disturbed by the external environment. At the same time, due to the adoption of the capacitive measurement principle, the sensor has good anti-interference ability and stability. This enables the sensor to maintain high reliability during long-term use and ensure the accuracy and stability of the measurement results.

[0032] The groove 8 on the upper plate 3 can be made by a suitable grooving process, such as the combined use of laser and engraving machine, which can improve the efficiency and accuracy of grooving. Laser grooving is used to quickly form the basic shape of the groove 8, while the engraving machine is used to finely process the depth and surface quality of the groove 8. This combined process can ensure that the distance between the electrode 7 and the pressure-sensitive film 4 is accurately controlled, thereby improving the measurement accuracy of the capacitance value and the sensitivity of the sensor.

[0033] In an optional embodiment, the wide-range pressure sensor further includes an air-conducting layer 5 , and the air-conducting layer 5 is disposed between the pressure-sensitive film 4 and the base 6 .

[0034] The main function of the above-mentioned gas-conducting layer 5 is to guide and distribute the measured gas entering the housing 1 and buffer the impact of the gas pressure. When the measured gas is filled into the base 6, the gas-conducting layer 5 first contacts the gas, which can reduce the direct impact of the gas on the pressure-sensitive membrane 4 and reduce the stress on the pressure-sensitive membrane 4. Thereby reducing the fluctuation of the capacitance value caused by the stress change and improving the stability and accuracy of the measurement. The gas-conducting layer 5 is made of a porous material or a material with good gas permeability to ensure that the gas can be evenly and efficiently distributed to the pressure-sensitive membrane 4. When designing the gas-conducting layer 5, it is necessary to select a material with appropriate porosity and air permeability to ensure that the gas can pass smoothly. According to the size of the sensor and the pressure measurement range, the thickness and shape of the gas-conducting layer 5 are reasonably designed to optimize the distribution of the gas and the response of the pressure-sensitive membrane 4. Ensure the sealing between the gas-conducting layer 5 and the base 6 and the pressure-sensitive membrane 4 to prevent gas leakage, thereby ensuring the accuracy of the measurement.

[0035] Adding an air-conducting layer 5 between the pressure-sensitive film 4 and the base 6 can reduce the stress on the pressure-sensitive film 4 when it directly contacts the base 6. This design helps to avoid the influence of stress caused by gas impact on the pressure-sensitive film 4, thereby reducing interference with changes in capacitance value and improving measurement accuracy and stability. Specifically, when the measured gas is filled into the base 6, the impact of gas pressure can be buffered. When the measured gas is filled into the base 6, the air-conducting layer 5 first contacts the gas, which can reduce the direct impact of the gas on the pressure-sensitive film 4, reduce the stress on the pressure-sensitive film 4, and thus extend its service life. In addition, the air-conducting layer 5 can also prevent impurities in the gas from directly contacting the pressure-sensitive film 4, reducing pollution and wear. The design of the air-conducting layer 5 can adapt to the measurement requirements of different pressure ranges. By adjusting the material and structure of the air-conducting layer 5, accurate measurement of different pressure ranges can be achieved.

[0036] In an optional embodiment, to further optimize the measurement performance of the sensor, the present invention sets the plurality of grooves 8 arranged on the upper plate 3 to different depths. By adjusting the depth of the grooves 8, the sensor can have different sensitivities in different pressure ranges, thereby achieving measurement of a wide range of pressures.

[0037] according to ,in, is the dielectric constant. The area of ​​electrode 7 or the distance between electrodes 7 When the voltage changes, it will affect the capacitance value of the parallel plate capacitor formed between the upper plate 3 and the pressure-sensitive film 4. . When the measured gas acts on the pressure-sensitive membrane 4, the pressure-sensitive membrane 4 will be deformed, thereby changing the capacitance value of the parallel plate capacitor, and further affecting the range of gas pressure. Due to the different electrode 7 area and groove 8 depth designs, the capacitance value and pressure range corresponding to each electrode 7 are different. In this way, a sensor that can measure a wider range of gas pressures can be designed, thereby solving the problem of narrow measurement range of traditional pressure sensors. This design adjusts the capacitance value by changing the area of ​​the electrode 7 and the distance between the electrodes 7, thereby achieving measurement of gases in different pressure ranges. This design has the advantages of a wide measurement range and high precision, and is suitable for various occasions that require accurate measured gas pressure. By accurately designing the depth of the groove 8, the sensor can have different sensitivities in different pressure ranges, thereby achieving accurate measurement of a wide range of pressures.

[0038] The present invention can make the sensor produce a larger capacitance value change under a smaller pressure change by setting the multiple grooves 8 on the upper plate 3 to different depths, thereby widening the measurement range while maintaining high accuracy. This enables the sensor to be suitable for a wider range of application scenarios, such as gas pressure measurement under high-pressure or low-pressure environments. By accurately designing the depth of the groove 8, the sensor can have more accurate measurement accuracy within different pressure ranges. This helps to avoid the error accumulation problem that may occur in wide-range measurements, thereby improving the overall measurement accuracy. Since the depth of the groove 8 can be accurately designed, the sensor can be customized for different application requirements. For example, for application scenarios that need to measure small pressure changes, a shallower groove 8 can be designed to increase sensitivity; and for application scenarios that need to measure a larger pressure range, a deeper groove 8 can be designed to maintain measurement accuracy.

[0039] In an optional embodiment, the shell 1 is provided with a pressing structure 2 , and the shell 1 is pressed onto the upper electrode plate 3 through its pressing structure 2 .

[0040] The above-mentioned clamping structure 2 is made of elastic material (such as rubber, silicone, etc.) and has certain elasticity and compressibility. The clamping structure 2 can be annular, strip-shaped or other shapes, and the specific shape depends on the design of the shell 1 and the measurement requirements of the sensor. The clamping structure 2 is connected to the shell 1 by bolts, snaps or other fixing methods, and fits tightly to the surface of the upper plate 3. The shell 1 not only protects the internal structure, but the clamping structure 2 of the shell 1 ensures that the shell 1 is in close contact with the upper plate 3 to avoid the infiltration of air or other media. This close contact not only improves the sealing of the sensor, but also reduces the measurement errors caused by vibration or impact.

[0041] Specifically, the wide-range pressure sensor provided by the present invention is a capacitive thin film pressure sensor. When the measured gas rushes in, the pressure-sensitive film 4 and the upper electrode plate 3 will move toward the direction of the clamping structure 2 to generate compressive stress. This compressive stress will not cause the structure to generate tearing force, thereby protecting the bonding part and avoiding damage to the structure. Through such a structural design, the pressure sensor can maintain long-term stable use and is not easily damaged by mechanical stress. In addition, the measurement accuracy can be maintained because the structural design reduces the influence of non-measurement factors on the capacitance value. At the same time, because the internal structure is well protected and not easily affected by the external environment, the reliability of the sensor is improved. This design ensures the high performance and durability of the capacitive thin film pressure sensor in vacuum measurement.

[0042] The materials of the housing 1 and the pressing structure 2 need to have good mechanical strength, corrosion resistance, wear resistance and stability. At the same time, the thermal expansion coefficient of the material should match that of other materials inside the sensor to avoid measurement errors caused by temperature changes.

[0043] In an optional embodiment, the pressure-sensitive membrane 4 divides the internal space of the shell 1 into a vacuum space and a measured space; wherein the area between the pressure-sensitive membrane 4 and the upper electrode plate 3 forms a vacuum space, and the area between the air inlet and the pressure-sensitive membrane 4 forms a measured space.

[0044] The pressure-sensitive membrane 4 is made of highly elastic and highly sensitive materials, such as metals, alloys or polymer materials, to ensure that it can produce obvious deformation when subjected to pressure changes. The area between the pressure-sensitive membrane 4 and the upper plate 3 is designed as a vacuum space. This space is evacuated by a vacuum pump and other equipment during the sensor manufacturing process to ensure that its internal pressure is much lower than atmospheric pressure. The existence of the vacuum space enables the pressure-sensitive membrane 4 to produce more obvious deformation when the pressure of the measured space changes, thereby improving the sensitivity of the sensor. The area between the air inlet and the pressure-sensitive membrane 4 is designed as the measured space. This space is connected to the measured gas and is used to receive the pressure changes of the measured gas. When the pressure of the measured gas changes, this change will directly act on the pressure-sensitive membrane 4, causing the pressure-sensitive membrane 4 to deform.

[0045] Due to the existence of the vacuum space, the pressure-sensitive membrane 4 can produce more obvious deformation when the pressure of the measured space changes. This deformation will be converted into a change in capacitance, thereby achieving accurate measurement of the pressure of the measured gas and improving the sensitivity of the sensor. At the same time, the vacuum space also reduces the interference of the external environment on the measurement performance of the sensor, improving the accuracy and stability of the measurement. The design of the pressure-sensitive membrane 4 enables the sensor to cover a wider pressure measurement range. Whether it is a small pressure change or a large pressure fluctuation, the sensor can accurately measure and respond. Moreover, the close fit between the pressure-sensitive membrane 4 and the housing 1 and the existence of the vacuum space enable the sensor to maintain stable measurement performance during long-term use.

[0046] In an optional embodiment, the material of the pressure-sensitive film 4 can be quartz, metal material, Inconel alloy, sapphire or diamond.

[0047] Quartz has a piezoelectric effect, that is, when it is subjected to pressure, an electric charge will be generated on its surface. This effect enables the quartz pressure-sensitive film 4 to convert pressure changes into electrical signals for output, thereby realizing pressure measurement. Metal materials have appropriate elasticity, can deform when subjected to pressure, and return to their original state after the pressure is released. This characteristic enables the metal pressure-sensitive film 4 to more accurately reflect the pressure changes of the measured gas. Inconel alloy is a high-performance nickel-based alloy with extremely high strength and stability, and can maintain excellent mechanical properties in a high-temperature environment. This enables the Inconel alloy pressure-sensitive film 4 to maintain accurate measurement in a high-temperature environment and is not easily failed due to thermal expansion or thermal stress. Moreover, Inconel alloy has good fatigue resistance and can withstand cyclic loads for a long time without failure. This makes the Inconel alloy pressure-sensitive film 4 have unique advantages in occasions where it needs to withstand pressure changes for a long time. Diamond has a high elastic modulus, can undergo moderate deformation when subjected to pressure, and quickly return to its original state after the pressure is released. This characteristic enables the diamond pressure-sensitive film 4 to more accurately reflect the pressure changes of the measured gas. Sapphire has good elasticity and can deform when subjected to pressure and return to its original shape after the pressure is released. Due to the hardness and elasticity of sapphire, it can more accurately reflect the pressure changes of the measured gas, thereby improving the measurement accuracy of the sensor.

[0048] In an optional embodiment, the material of the upper plate 3 and the gas-conducting layer 5 needs to be consistent with the pressure-sensitive film 4 or a material with a thermal expansion coefficient similar to that of the pressure-sensitive film 4 is selected. This helps to reduce the thermal stress caused by temperature changes, thereby avoiding damage to the sensor structure or performance degradation. For example, if the pressure-sensitive film 4 is made of quartz material, the upper plate 3 and the gas-conducting layer 5 can also select quartz or other silicate materials with similar thermal expansion coefficients. If the pressure-sensitive film 4 is a metal material, the upper plate 3 and the gas-conducting layer 5 can select the same metal or other metal materials with similar thermal expansion coefficients. The material of the base 6 also needs to be similar to the thermal expansion coefficient of the gas-conducting layer 5. Thermal stress can be reduced to ensure the stability and reliability of the sensor under temperature changes. The base 6 material can be selected from stainless steel, aluminum alloy, copper alloy, etc., which usually have good mechanical properties and thermal stability.

[0049] The present invention can significantly reduce thermal stress caused by temperature changes by selecting materials with similar thermal expansion coefficients. This helps to avoid damage to the sensor structure, such as cracking, deformation, etc. The matching of thermal expansion coefficients between materials can reduce sensor performance fluctuations caused by temperature changes. This helps to improve the measurement accuracy and stability of the sensor, so that it can maintain excellent performance in various environments. Moreover, good matching between materials can ensure that the sensor has excellent response speed and sensitivity during the measurement process. This helps to quickly and accurately capture the pressure changes of the measured gas.

[0050] By optimizing the structural design and processing technology, the wide-range pressure sensor of the present invention can simultaneously measure a wide range of gas pressures, reduce stress interference, improve measurement accuracy and stability, and extend the service life of the sensor. Drift refers to the error that occurs when the sensor output changes over time. By optimizing the design and processing technology, drift caused by temperature changes, mechanical stress or other external factors can also be reduced. The pressure sensor of this design has better long-term stability and reliability, reduces drift, and the measurement results are more reliable.

[0051] The manufacturing method of the wide-range pressure sensor provided by the present invention is described below. The manufacturing method of the wide-range pressure sensor described below and the wide-range pressure sensor described above can be referred to each other.

[0052] The present invention provides a method for manufacturing a wide-range pressure sensor, comprising: The housing 1 is mounted on the base 6 to provide support and protection for the subsequent sensor assembly. An air inlet is reserved on the base 6 for introducing the pressure medium to be measured so that the sensor can sense external pressure changes.

[0053] A plurality of electrodes 7 of different areas or shapes are arranged on the pressure-sensitive film 4. These electrodes 7 are used to sense the deformation of the pressure-sensitive film 4 under the action of pressure and convert the deformation into an electrical signal for output. By arranging electrodes 7 of different areas or shapes, the sensitivity and measurement range of the sensor can be increased, so that it can more accurately reflect the changes in the pressure to be measured.

[0054] A plurality of grooves 8 corresponding to the electrodes 7 on the pressure-sensitive film 4 are formed on the upper electrode plate 3, and the grooves 8 are used to cooperate with the electrodes 7 on the pressure-sensitive film 4 to form a conductive path. The shape, size and position of the grooves 8 should match the electrodes 7 on the pressure-sensitive film 4 to ensure that the sensor can stably and reliably output electrical signals when working.

[0055] The upper electrode plate 3 is arranged in the housing 1 to keep a certain distance from the pressure-sensitive film 4. The pressure-sensitive film 4 is arranged in the housing 1 and is located below the upper electrode plate 3. When the pressure medium to be measured enters the housing 1 through the air inlet, the pressure-sensitive film 4 is deformed by the pressure.

[0056] The traditional sandblasting method may be difficult to open grooves 8 of different areas or shapes on the same plane, because it is difficult to accurately control the size and depth of the groove 8 during the sandblasting process. In order to solve this problem, the present invention uses laser and engraving machine, and these two methods can be used separately or simultaneously. Laser grooving is a high-precision processing method that can accurately control the shape, size and depth of the groove 8. Laser grooving is fast and suitable for rough processing, that is, first cutting out the approximate shape and size of the groove 8 on the material. The engraving machine is a high-precision CNC processing equipment that can be used to finely process the depth and surface smoothness of the groove 8. On the basis of laser grooving, the depth of the groove 8 can be further adjusted by using the engraving machine, and the surface of the groove 8 can be ensured to be smooth, thereby improving the distance control accuracy between the pressure-sensitive film 4 and the electrode 7 of the upper plate 3. Combining these two methods, the laser can be used for rough cutting first to quickly form the basic shape of the groove 8, and then the engraving machine can be used for fine processing to control the depth and surface quality of the groove 8. This can ensure that the distance between the electrode 7 and the pressure-sensitive film 4 is accurately controlled, thereby improving the measurement accuracy of the capacitance value and the sensitivity of the sensor. In addition, the combined use of laser and engraving machine can also improve production efficiency, because laser grooving can quickly complete most of the work, while the engraving machine can improve the quality of the processed surface while ensuring accuracy. This method is an efficient and high-precision process option in pressure sensor manufacturing.

[0057] By adopting a suitable slotting method, the distance between the pressure-sensitive film 4 and the electrode 7 of the upper plate 3 can be accurately controlled, which helps to reduce the initial error of the capacitance. The reduction of the initial error of the capacitance means that the sensor is more accurate at the beginning of the measurement, thereby improving the measurement accuracy of the entire pressure sensor.

[0058] By providing a plurality of electrodes 7 of different areas or shapes, the sensitivity of the sensor can be increased, so that it can more accurately sense the change of the pressure to be measured, and can also measure the pressure change in a larger range. At the same time, the matching relationship between the upper electrode plate 3 and the pressure-sensitive film 4 can also further reduce the measurement error and improve the measurement accuracy of the sensor.

[0059] In an optional embodiment, the method further includes: An air-conducting layer 5 is provided between the pressure-sensitive film 4 and the base 6. Adding the air-conducting layer 5 between the pressure-sensitive film 4 and the base 6 can reduce the stress on the pressure-sensitive film 4 when it directly contacts the base 6. This design helps to avoid the influence of the stress caused by gas impact on the pressure-sensitive film 4, thereby reducing the interference with the change of the capacitance value and improving the accuracy and stability of the measurement.

[0060] The diameter of the electrode 7 is designed to be within the range of 4-10 mm to adapt to different pressure ranges. The grooving process of the upper plate 3 is critical because it requires precise control of the shape, size and depth of the groove 8. First, a circle 2-4 mm larger than the diameter of the electrode 7 of the pressure-sensitive film 4 is cut out by laser, which makes it easier to plate the electrode 7 and avoids plating the electrode 7 on the part outside the groove. Then, the grooved part is finely cut using a precision engraving machine to obtain a precise depth (within the range of 10-30 microns). This method of rough cutting and then fine engraving can increase the processing speed while ensuring the spacing and smoothness of the grooved surface, thereby more accurately measuring the capacitance change value. The bonding between the base 6, the gas-conducting layer 5, the pressure-sensitive film 4, the upper plate 3 and the inner ring of the shell 1 is a key step to ensure the structural integrity and sealing of the sensor. The bonding method can be selected from glass powder sintering or laser welding, both of which can provide good mechanical strength and electrical insulation performance. By precisely controlling the shape, area and depth of the groove of the electrode 7, a stable parallel plate capacitor structure can be formed between the pressure-sensitive film 4 and the upper plate 3. This structure helps to improve the accuracy of capacitance measurement and reduce the influence of external factors on the measurement results.

[0061] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, rather than to limit it. Although the present invention has been described in detail with reference to the aforementioned embodiments, those skilled in the art should understand that they can still modify the technical solutions described in the aforementioned embodiments, or make equivalent replacements for some of the technical features therein. However, these modifications or replacements do not deviate the essence of the corresponding technical solutions from the spirit and scope of the technical solutions of the embodiments of the present invention.

Claims

1. A wide range pressure sensor, characterized in that: include: Base, shell, pressure-sensitive film and upper plate; The pressure-sensitive film and the upper electrode plate are both located in the shell; The base is mounted on the bottom of the shell and is provided with an air inlet so that the measured gas can enter the shell; The pressure-sensitive film is arranged above the base, and the upper electrode plate is arranged above the pressure-sensitive film to form a parallel plate capacitor between the upper electrode plate and the pressure-sensitive film; A plurality of electrodes with different areas or shapes are arranged on the pressure-sensitive film, and a groove corresponding to the electrodes is arranged on a side of the upper electrode plate facing the pressure-sensitive film.

2. The wide-range pressure sensor according to claim 1, characterized in that: It also includes an air guide layer, which is arranged between the pressure-sensitive film and the base.

3. The wide-range pressure sensor according to claim 1 or 2, characterized in that: The depths of the plurality of grooves arranged on the upper electrode plate are different.

4. The wide-range pressure sensor according to claim 3, characterized in that: The depth of the groove is 10 micrometers to 30 micrometers.

5. The wide-range pressure sensor according to claim 1, characterized in that: The shell is provided with a pressing structure, and the shell is pressed onto the upper plate through the pressing structure.

6. The wide-range pressure sensor according to claim 1, characterized in that: The pressure-sensitive film divides the internal space of the shell into a vacuum space and a measured space; wherein the area between the pressure-sensitive film and the upper electrode plate forms a vacuum space, and the area between the air inlet and the pressure-sensitive film forms a measured space.

7. The wide-range pressure sensor according to claim 1, characterized in that: The material of the pressure-sensitive film is quartz, metal material, Inconel alloy, sapphire or diamond.

8. The wide-range pressure sensor according to claim 2, characterized in that: The upper electrode plate, the gas-conducting layer and the pressure-sensitive film are made of the same material.

9. A method for manufacturing a wide-range pressure sensor according to any one of claims 1 to 8, characterized in that: The method comprises: Installing a shell on the base and reserving an air inlet; Arranging a plurality of electrodes with different areas or shapes on the pressure-sensitive film; forming a plurality of grooves on the upper electrode plate corresponding to the electrodes on the pressure-sensitive film; Disposing the upper electrode plate in the housing; The pressure-sensitive film is arranged in the housing and below the upper electrode plate.

10. The method for manufacturing a wide-range pressure sensor according to claim 9, characterized in that: The method further comprises: An air guide layer is arranged between the pressure-sensitive film and the base.

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