Icing sensor

Abstract

The application relates to the technical field of sensors, in particular to an icing sensor. The utility model provides a high-precision miniaturized icing sensor. The utility model discloses a silicon substrate 15, characterized in that a groove is arranged at the middle of the upper end of the silicon substrate 15, a flat film 19 is fixed to the upper end of the silicon substrate 15, a cavity 20 is formed between the flat film 19 and the groove area of the silicon substrate 15, driving electrodes and detecting electrodes are arranged on the silicon substrate 15 in the cavity 20, the flat film 19 is a common electrode, the common electrode, the driving electrodes and the detecting electrodes form a capacitive coupling structure, and the capacitance between the detecting electrodes and the common electrode is a detection capacitance.

Description

Technical Field

[0001] This utility model belongs to the field of sensor technology, and in particular relates to an icing sensor. Background Technology

[0002] The sensors and detection methods proposed so far for quantitatively detecting the thickness of ice on the surfaces of wind turbine blades, aircraft, power transmission lines, towers, insulators and other relatively stationary objects can be divided into the following two categories.

[0003] The first category is direct measurement methods, which involve directly measuring the thickness of ice on the surface of an object by human intervention or other equipment. Several typical direct measurement methods include: (1) manual measurement, which relies on human beings to directly measure the thickness of ice on the ground using a ruler; (2) visual inspection, which relies on human eyes to observe the thickness of ice on the surface of a probe or other components; (3) infrared blocking method, which detects the thickness of ice on the probe surface by measuring the degree to which the probe blocks infrared light in the infrared light path; and (4) photographic method, which uses a camera to take a cross-sectional photo of the ice layer and uses digital image processing technology to identify the upper and lower interfaces of the ice layer in the photo to determine the thickness of the ice layer.

[0004] The second type is the indirect measurement method. This method is based on the differences in optical, electrical, and mechanical properties between ice and air and water. The thickness of ice is detected by detecting these characteristic parameters. Several typical indirect measurement methods are: (1) Fiber optic method: Based on the reflection, refraction, and scattering characteristics of ice on light, the thickness of ice is detected by detecting the degree of reflection, refraction, and scattering of incident light by the ice layer. (2) Resistance method: Based on the difference in resistivity, the resistance value between two electrodes is detected to determine whether the material between the electrodes is ice. Multiple pairs of electrodes are then arranged at equal distances, with each electrode serving as a scale for ice thickness. The total ice thickness is equal to the product of the distance between adjacent electrode pairs and the number of electrode pairs with ice as the material between them. (3) Resonance method: This includes the magnetostrictive vibrating cylinder method and the piezoelectric flat film 19 method. The principle of the magnetostrictive vibrating cylinder method is that the ice on the vibrating cylinder increases the mass of the vibrating cylinder, which reduces the resonant frequency of the vibrating cylinder. The piezoelectric flat film 19 method is based on the fact that the ice on the flat film 19 increases the stiffness of the flat film 19, which increases the resonant frequency of the flat film 19.

[0005] Among the aforementioned typical methods for measuring ice thickness, manual measurement and visual inspection cannot perform real-time online detection of ice; the infrared blocking method and the imaging method have reduced measurement accuracy when the surface of the object being measured is vibrating, and icing of the camera lens can also cause the imaging method to fail; the fiber optic and resistive methods are very sensitive to the state of ice (transparent ice or frost ice) and composition (type and proportion of impurities), and the uncertainty of the ice state and composition will cause uncertainty in the detection results; the magnetostrictive vibrating cylinder method and the piezoelectric level film method require electromagnetic coils and piezoelectric ceramic excitation sources, respectively, which are difficult to miniaturize. Utility Model Content

[0006] This invention addresses the aforementioned problems by providing a high-precision, miniaturized icing sensor.

[0007] To achieve the above objectives, the present invention adopts the following technical solution: the present invention includes a silicon substrate 15, characterized in that a groove is provided in the middle of the upper end of the silicon substrate 15, a flat film 19 is fixed on the upper end of the silicon substrate 15, a cavity 20 is formed between the flat film 19 and the groove area of ​​the silicon substrate 15, a driving electrode and a detection electrode are provided on the silicon substrate 15 inside the cavity 20, the flat film 19 is a common electrode, the common electrode forms a capacitive coupling structure with the driving electrode and the detection electrode, and the capacitance between the detection electrode and the common electrode is the detection capacitance.

[0008] As a preferred embodiment, the cavity 20 of this invention is provided with a dielectric layer 16, which covers the upper ends of the driving electrode and the detection electrode.

[0009] As another preferred embodiment, the flat film 19 of this invention is a diffused silicon layer.

[0010] As another preferred embodiment, the driving electrode, detection electrode, and common electrode of this invention are respectively connected to their respective electrode leads.

[0011] As another preferred embodiment, the driving electrode of this invention is located in the center of the silicon substrate 15 within the cavity 20, and the detection electrode surrounds the driving electrode.

[0012] As another preferred embodiment, the driving electrode of this invention is a ring electrode.

[0013] As another preferred embodiment, the detection electrode and driving electrode of this invention each include two or more ring electrodes, forming a multi-ring detection structure.

[0014] As another preferred embodiment, the detection electrode and the driving electrode of this utility model both include two ring electrodes. The inner ring electrode 5 and the outer ring electrode 6 of the detection electrode are respectively provided with a driving electrode through-hole 12 on one side. The inner ring electrode 5 and the outer ring electrode 6 of the detection electrode on both sides of the driving electrode through-hole 12 are connected by a horizontal strip detection electrode 1.

[0015] The inner annular electrode 4 and the outer annular electrode 7 of the driving electrode away from the driving electrode through-hole 12 are respectively provided with a first opening 11. The inner annular electrode 4 and the outer annular electrode 7 of the driving electrode on both sides of the first opening 11 are connected by a short horizontal strip driving electrode 8.

[0016] The driving electrode passing through the driving electrode through-hole 12 is two parallel long horizontal strip driving electrodes 2. The outer ring electrode 7 of the driving electrode away from the first opening 11 is provided with a second opening 13. The outer ring electrode 7 of the driving electrode on both sides of the second opening 13 is connected to the inner end of a long horizontal strip driving electrode 2. The outer ends of the two long horizontal strip driving electrodes 2 are connected to the driving electrode lead wire 3.

[0017] The outer annular electrode 6 of the detection electrode away from the drive electrode through-hole 12 is provided with a third opening 14. The outer annular electrode 6 of the detection electrode on both sides of the third opening 14 is connected to the inner end of a long horizontal strip detection electrode 9. The outer ends of the two long horizontal strip detection electrodes 9 are connected to the detection electrode lead wire 10.

[0018] As another preferred embodiment, both the detection electrode and the driving electrode of this invention are made of aluminum strip electrodes.

[0019] As another preferred embodiment, the widths of the annular electrode, the horizontal strip detection electrode 1, the short horizontal strip driving electrode 8, the long horizontal strip driving electrode 2, the driving electrode lead 3, the long horizontal strip detection electrode 9, the detection electrode lead 10, the distance between the two long horizontal strip driving electrodes 2, the distance between the inner and outer annular electrodes, the distance between the two short horizontal strip driving electrodes 8, and the distance between the two long horizontal strip detection electrodes 9 are all 20 micrometers.

[0020] As another preferred embodiment, the driving electrode and the detection electrode of this invention are two concentric electrodes, with the central circular one being the driving electrode and the outer circular one being the detection electrode.

[0021] As another preferred embodiment, the dielectric layer 16 of this invention is made of an insulating material with a low dielectric constant (e.g., silicon dioxide).

[0022] As another preferred embodiment, the sensor of this invention has a surface protective film 21.

[0023] As another preferred embodiment, the protective film 21 of this invention is a silicon dioxide protective film 21.

[0024] As another preferred embodiment, the thickness of the silica protective film 21 of this invention is 0.15 μm.

[0025] Secondly, a drainage groove 17 is provided on the flat membrane 19 on the outer periphery of the cavity 20 of this utility model.

[0026] In addition, the upper ends of the flat membrane 19 on both sides of the drainage groove 17 on the outer periphery of the cavity 20 of the present invention are respectively provided with a driving electrode connection part and a detection electrode connection part, and a common electrode connection part is provided in the middle of the flat membrane 19.

[0027] The beneficial effects of this utility model.

[0028] When ice forms on the flat diaphragm 19 of this invention, the ice increases the stiffness of the flat diaphragm 19, reducing its deformation. This increases the distance between the two electrodes of the detection capacitor, thus decreasing the detection capacitance. By monitoring the change in the detection capacitance, the thickness and extent of the ice on the surface of the flat diaphragm 19 can be determined. The thicker the ice, the greater the stiffness of the flat diaphragm 19, the smaller the deformation, and the greater the decrease in the detection capacitance. Combined with a preset threshold, the system can determine in real time whether an icing state has been entered and issue a corresponding warning signal. This detection mechanism based on capacitance changes not only has a fast response speed but also good repeatability and stability, maintaining high precision operation under complex climatic conditions.

[0029] The detection principle of this utility model is based on the principle that ice formation on the flat diaphragm 19 changes the stiffness of the flat diaphragm 19. Unlike the piezoelectric flat diaphragm 19, the flat diaphragm 19 of this utility model's capacitive icing sensor is statically deformed. Ice formation on the flat diaphragm 19 causes changes in the stiffness and deformation of the flat diaphragm 19.

[0030] The flat diaphragm 19 of this sensor is fixed on the silicon substrate 15, and a cavity 20 is formed between the flat diaphragm 19 and the silicon substrate 15. The driving electrode and the detection electrode are respectively disposed between the flat diaphragm 19 and the silicon substrate 15. The icing state is reflected by the capacitance change. The common electrode is disposed below the silicon substrate 15 for stable output of the reference signal.

[0031] Due to the excellent mechanical properties and temperature stability of the silicon substrate and flat film 19, the sensor can maintain good performance even in low-temperature environments. Utilizing the capacitive detection principle, the sensor can detect minute stiffness changes in the early stages of icing, achieving high-resolution, high-sensitivity measurement of icing thickness. This provides accurate icing early warning and monitoring capabilities for equipment such as aircraft and wind turbines.

[0032] This invention relates to an icing sensor constructed from a chip, achieving miniaturization of the icing sensor. Attached Figure Description

[0033] The present invention will be further described below with reference to the accompanying drawings and specific embodiments. The scope of protection of the present invention is not limited to the following description.

[0034] Figure 1 This is a schematic diagram of the structure of this utility model.

[0035] Figure 2 This is a top view of the utility model.

[0036] Figure 3 This is a graph showing the linearity of the sensor output capacitance value at -40℃ as a function of ice thickness.

[0037] Figure 4 This is a graph showing the linearity of the sensor output capacitance value at 0℃ as a function of ice thickness.

[0038] Figures 5-13 This is a process flow diagram of the sensor of this utility model.

[0039] Figure 14 This is a diagram of a MEMS icing capacitor array composed of multiple icing sensors of this invention. Detailed Implementation

[0040] like Figure 1 As shown, this utility model includes a silicon substrate 15, a groove is provided in the middle of the upper end of the silicon substrate 15, a flat film 19 is fixed at the upper end of the silicon substrate 15, a cavity 20 is formed between the flat film 19 and the groove area of ​​the silicon substrate 15, a driving electrode and a detection electrode are provided on the silicon substrate 15 inside the cavity 20, the flat film 19 is a common electrode, the common electrode forms a capacitive coupling structure with the driving electrode and the detection electrode, and the capacitance between the detection electrode and the common electrode is the detection capacitance.

[0041] A dielectric layer 16 is provided inside the cavity 20, covering the upper ends of the driving electrode and the detection electrode. The dielectric layer 16 covers the driving electrode and the detection electrode inside the cavity 20, serving to isolate and protect the surface, preventing interference from the external environment.

[0042] The flat film 19 is a diffused silicon layer.

[0043] The driving electrode, detection electrode, and common electrode are each connected to their respective electrode leads. The electrode leads connect the electrodes and are used to output detection signals.

[0044] The driving electrode is located in the center of the silicon substrate 15 within the cavity 20, and the detection electrode surrounds the driving electrode. This arrangement effectively ensures the uniformity and stability of capacitance changes. It also makes the electric field distribution in the dielectric more uniform, thus avoiding sudden changes in capacitance value caused by localized electric field concentration. In terms of material selection, dielectric materials with excellent temperature stability can be used (i.e., the dielectric layer 16 is made of silicon dioxide or silicon nitride). The coefficient of thermal expansion of such materials matches that of the electrode materials, greatly reducing the impact of temperature fluctuations on capacitance value and ensuring a constant electrode spacing, maintaining a stable relative position even under vibration or mechanical shock conditions. The combined effect of these measures ensures that capacitance changes maintain both good uniformity and excellent long-term stability.

[0045] The driving electrode is a ring electrode.

[0046] Both the detection electrode and the driving electrode include two or more ring electrodes, forming a multi-ring detection structure.

[0047] The detection electrodes employ two or more rings, arranged around the driving electrode to form a multi-ring detection structure, further enhancing the detection electrodes' ability to sense deformation of the flat film 19. Multiple ring electrodes can capture minute capacitance changes, enhancing the system's resolution and detection accuracy. Furthermore, the multi-ring structure effectively suppresses external interference, improving signal stability and repeatability, thus ensuring the sensor maintains good operating performance even in complex environments.

[0048] like Figure 2 As shown, both the detection electrode and the driving electrode include two ring electrodes. The inner ring electrode 5 and the outer ring electrode 6 of the detection electrode are respectively provided with a driving electrode through-hole 12 on one side. The inner ring electrode 5 and the outer ring electrode 6 of the detection electrode on both sides of the driving electrode through-hole 12 are connected by a horizontal strip detection electrode 1.

[0049] The inner annular electrode 4 and the outer annular electrode 7 of the driving electrode away from the driving electrode through-hole 12 are respectively provided with a first opening 11. The inner annular electrode 4 and the outer annular electrode 7 of the driving electrode on both sides of the first opening 11 are connected by a short horizontal strip driving electrode 8.

[0050] The driving electrode passing through the driving electrode through-hole 12 is two parallel long horizontal strip driving electrodes 2. The outer ring electrode 7 of the driving electrode away from the first opening 11 is provided with a second opening 13. The outer ring electrode 7 of the driving electrode on both sides of the second opening 13 is connected to the inner end of a long horizontal strip driving electrode 2. The outer ends of the two long horizontal strip driving electrodes 2 are connected to the driving electrode lead wire 3.

[0051] The outer annular electrode 6 of the detection electrode away from the drive electrode through-hole 12 is provided with a third opening 14. The outer annular electrode 6 of the detection electrode on both sides of the third opening 14 is connected to the inner end of a long horizontal strip detection electrode 9. The outer ends of the two long horizontal strip detection electrodes 9 are connected to the detection electrode lead wire 10.

[0052] By setting the first opening 11, unnecessary current paths can be avoided between the inner annular electrode 4 and the outer annular electrode 7 of the driving electrode on the side away from the driving electrode through-hole 12, thereby precisely controlling the direction and distribution of current flow. This helps improve the working efficiency of the electrodes and the accuracy of detection, enabling more accurate capture of electrical signals such as capacitance changes during the detection process. Simultaneously, the presence of the first opening 11 also reduces electromagnetic interference between the electrodes, ensuring the stability and reliability of the entire detection system. In practical applications, this design can adapt to different working environments and detection requirements, ensuring the equipment operates normally under various complex conditions, providing strong support for detection and measurement work in related fields.

[0053] A voltage is applied between the driving electrode and the common electrode, causing the flat diaphragm 19 to deform. As the flat diaphragm 19 deforms, the capacitance between the driving electrode and the common electrode changes. This change is detected by the detection electrode and transmitted to the detection circuit. The electrostatic driving method generates an electrostatic attraction by applying a voltage, causing a minute displacement of the flat diaphragm 19, thereby changing the capacitance. This structural design enables the sensor to operate with extremely low power consumption and achieve real-time monitoring of icing conditions. The concentric square arrangement of the electrodes not only improves the sensitivity to capacitance changes but also effectively reduces interference from parasitic capacitance, improving detection accuracy.

[0054] Both the detection electrode and the driving electrode are made of aluminum strip electrodes.

[0055] The widths of the annular electrode, the horizontal strip detection electrode, the short horizontal strip driving electrode, the long horizontal strip driving electrode, the driving electrode lead wire, the long horizontal strip detection electrode, the detection electrode lead wire, the distance between the two long horizontal strip driving electrodes, the distance between the inner and outer annular electrodes, the distance between the two short horizontal strip driving electrodes, and the distance between the two long horizontal strip detection electrodes are all 20 micrometers.

[0056] The driving electrode and detection electrode are two concentric electrodes, with the central circular driving electrode and the outer annular detection electrode. The circular driving electrode increases its area, thereby improving the efficiency of electrostatic driving. The more uniform electric field distribution at the edge of the circular driving electrode contributes to the uniformity of deformation of the flat film 19, avoiding the risk of localized excessive deformation or breakdown due to electric field concentration. Simultaneously, this design enhances the symmetry of the overall structure, improving the stability and reliability of the device. In practical applications, the shape of the driving electrode can be optimized according to specific requirements to achieve the best driving effect and sensitivity.

[0057] The common electrode is located in the central region of the flat film 19, forming a capacitive coupling structure with the driving electrode and the detection electrode, ensuring stable capacitance change output under electrostatic drive. This structural design allows the sensor to maintain good linear response and repeatability under different ambient temperature and humidity conditions, improving the overall system's adaptability. Simultaneously, the common electrode uses a highly conductive material (i.e., the aforementioned "flat film 19 is a diffused silicon layer"), reducing the electrode's equivalent resistance and improving signal transmission efficiency.

[0058] The system accurately determines ice thickness by real-time detection of capacitance changes. Through scientific optimization of the geometric parameters of the driving electrode, detection electrode, and common electrode, stringent requirements for measurement accuracy are met. The principle behind this method is as follows: when ice forms on the surface of the flat membrane 19, the ice layer exerts mechanical stress on it, causing a change in its physical rigidity and deformation. As the common electrode, the deformation of the flat membrane 19 alters the distance and facing area between it and the driving and detection electrodes, thus affecting the capacitance value. This capacitance change has a linear relationship with the deformation of the flat membrane 19 (i.e., ice thickness). The thicker the ice layer, the greater the pressure on the flat membrane 19, the greater the deformation, the smaller the electrode spacing, and the more significant the increase in capacitance. By real-time monitoring of capacitance changes and combining this with a subsequently calibrated mathematical model of "ice thickness - deformation - capacitance change," the system can accurately deduce the ice thickness. This principle utilizes the synergistic effect of structural mechanics and capacitive coupling to avoid the problem of traditional dielectric constant detection being easily affected by environmental humidity. It can maintain stable detection accuracy even in complex environments such as low temperature and high humidity, and is especially suitable for key components such as aero-engine blades and wind turbine blades that require dynamic monitoring of icing status.

[0059] The specific scheme for configuring the geometric parameters is as follows:

[0060] like Figure 1 As shown, the optimal electrode spacing D between the driving electrode, the detection electrode and the common electrode is set to be between 0.45 μm and 1.2 μm, which performs excellently in the ice thickness measurement range of 0 mm to 10 mm and can stably achieve high-precision measurement results.

[0061]

[0062] Table 1. Experimental data (spacing D is 1 micrometer, output of capacitance of MEMS icing sensor at different temperatures as ice thickness changes)

[0063]

[0064]

[0065] Table 2. With a spacing D of 1 micrometer, the average capacitive response sensitivity of the full-temperature sensor to a 1-millimeter ice thickness variation can reach approximately 0.10 picofarads / mm.

[0066] Experimental data tables 1 and 2 show that this spacing D configuration ensures sufficient signal sensitivity while effectively avoiding signal interference between electrodes, thus achieving ideal measurement accuracy in ice thickness detection. This optimized design provides reliable technical support for ice monitoring and meets the stringent requirements for measurement accuracy.

[0067] Tables 1 and 2 further demonstrate that, within the typical operating temperature range of -40℃ to 0℃, when the electrode spacing D is maintained at 1 micrometer, the sensor achieves an average capacitive response sensitivity of approximately 0.10 picofarads / mm for ice thickness variations of 1 millimeter. This result fully verifies the high-precision characteristics of this geometric parameter configuration scheme. To complement the high performance of the electrode system, a high-precision capacitive sensor signal conditioning chip (such as the JHM2031 chip) can be used. The JHM2031 chip possesses excellent noise suppression and signal processing capabilities, enabling precise capture of minute capacitance changes. This allows for accurate capture of minute capacitance variations, thereby precisely calculating changes in ice thickness.

[0068] pass Figure 3 It can be seen that at -40℃, the linearity of the output capacitance value of the sensor of this utility model with the change of ice thickness is very good, and the linearity R2 reaches 0.989.

[0069] pass Figure 4 It can be seen that at 0℃, the linearity of the output capacitance value of the sensor of this utility model with the change of ice thickness is very good, and R2 reaches 0.9893.

[0070] The dielectric layer 16 is made of an insulating material with a low dielectric constant (e.g., silicon dioxide).

[0071] The sensor features a surface protective film 21, which is made of silicon dioxide. To improve the sensor's environmental adaptability and long-term stability, a protective film 21 with good insulation and chemical stability is coated on the sensor surface. This protective film 21 effectively isolates the sensor's internal electrode structure from external moisture, dust, and corrosive gases, while not affecting the normal deformation of the flat film 19 or the sensitivity of capacitance changes. In extreme temperature environments, the protective film 21 also provides a certain degree of thermal isolation, mitigating the impact of sudden temperature changes on the sensor's internal structure, thus providing a solid guarantee for achieving high-precision and high-stability icing detection. Through the above structural design and material selection, the sensor not only exhibits excellent detection performance under normal temperature and humidity conditions but also demonstrates outstanding adaptability and stability under complex environmental conditions such as low temperature, high humidity, and icing.

[0072] The silica protective film 21 has a thickness of 0.15 μm. The silica protective film 21 can be deposited on the substrate surface using conventional techniques such as chemical vapor deposition (CVD), physical vapor deposition (PVD), and plasma-enhanced chemical vapor deposition (PECVD).

[0073] A drainage groove 17 is provided on the flat membrane 19 on the outer periphery of the cavity 20. The drainage groove 17 facilitates the drainage of water from melting ice and can also quickly remove water droplets condensed in a high humidity environment, preventing false triggering or signal drift caused by water accumulation.

[0074] The drainage ditch 17 can be made using precision micromachining technology or photolithography (a conventional process), and can be tightly integrated with the main structure of the sensor to ensure drainage efficiency without compromising the overall sealing performance.

[0075] The upper ends of the flat membrane 19 on both sides of the drainage ditch 17 on the outer periphery of the cavity 20 are respectively provided with a driving electrode connection part and a detection electrode connection part, and a common electrode connection part is provided in the middle of the flat membrane 19.

[0076] Multiple icing sensors (i.e., multiple tiny capacitive units) can be assembled into a MEMS icing capacitor array, or capacitor unit array, effectively avoiding the edge electric field distortion effect common in traditional capacitor units, thus significantly improving the overall performance of the sensor. This innovative array structure not only ensures the uniformity of the electric field distribution but also plays a crucial role in improving the linearity of the output signal, resulting in significant improvements in multiple performance indicators such as measurement accuracy, stability, and reliability. Especially in high-precision measurement applications, this design can effectively suppress the generation of nonlinear errors, providing an important guarantee for the stable operation of the sensor under complex working conditions. This array design ensures that the output signal of the sensor maintains a high degree of linearity under different operating conditions, thereby significantly improving the accuracy and reliability of measurement data. The unique structure of the capacitor unit array not only optimizes the sensor's sensitivity but also achieves linear compensation of the output signal through uniformly distributed capacitor units, enabling the sensor to maintain good linear response characteristics over a wide measurement range. When icing occurs, the accumulation of ice causes changes in capacitance. Because the individual capacitor units work independently yet collaboratively, they can sense the icing situation from multiple dimensions and angles. This makes the electric field distribution of each capacitor unit more uniform and reduces interference caused by edge effects.

[0077] like Figure 14As shown, the MEMS icing capacitor array can be a square array, comprising two parallel arrays. The detection electrodes of each icing sensor in each array are connected together, as are the driving electrodes and common electrodes. Each array is divided into left and right side arrays, connected in parallel. The outer contour of each side array is square, with icing sensors staggered in the center. The left side array of the upper array is smaller than the right side array, and the left side array of the lower array is larger than the right side array. The lower end of the right side array of the upper array is flush with the upper end of the left side array of the lower array. This design improves the linearity of the MEMS icing capacitor array.

[0078] The icing sensor of this utility model can be manufactured using the following process steps:

[0079] Step 1: Etch to form the Si cavity 20 structure (i.e., "the cavity 20 is formed between the flat film 19 and the groove area of ​​the silicon substrate 15"). Layer 1: After photolithography, etch Si (e.g., 5um deep) to form the Si cavity 20 structure. Then, form thermally oxidized SiO2 (300nm) through conventional thermal oxidation process.

[0080] Step 2: Form metal electrodes, Layer 2, sputter metal Al (e.g., 300nm), photolithography followed by etching of Al to form Al electrodes (i.e., driving electrode and detection electrode).

[0081] Step 3: Form a SiO2 insulating layer, Layer 3, grow SiO2 by PECVD, and form a SiO2 isolation layer and dielectric layer 16 after photolithography.

[0082] Step 4: Form heavily doped Si on the front side, bond the heavily doped Si layer SOI on the front side, and etch away the handle layer Si (substrate silicon) to form a heavily doped Si thin film (i.e., flat film 19) and a boxSiO2 layer.

[0083] Step 5: Etch SiO2 and Si, Layer 4, photolithography layer 4, etch SiO2 / Si / SiO2 layer to expose Al layer; PECVD grow SiO2 layer to protect Si sidewalls.

[0084] Step 6: Expose the lead area, Layer 5, photolithography Layer 5, etch SiO2 to expose Al leads and Si.

[0085] Step 7: Form Al leads (i.e., the aforementioned "electrode connection portion") Figure 1 (Referring to label "18"), Layer 6, sputter Al layer (e.g., 1µm), photolithography Layer 6, and etch Al.

[0086] Step 8: Form a SiO2 insulating layer (i.e., the aforementioned "protective film 21"), expose the Al leads, Layer 7, PECVD grow SiO2 (e.g., 0.15um, i.e., "the thickness of the silicon dioxide protective film 21 is 0.15um"), photolithographically etch Layer 7, and etch the SiO2 to expose the Al leads.

[0087] Step 9: Photolithography Layer 8, etching SiO2, and continuing to etch the underlying Si to form the outer drainage trench 17.

[0088] The silicon flat diaphragm 19 employs a thickness at the micrometer level (e.g., 0.5 micrometers to 50 micrometers), making it highly sensitive to the stiffness changes caused by icing. Its capacitive output responds very sensitively and rapidly to changes in diaphragm stiffness, enabling ultra-high sensitivity detection of icing. It can perform fixed-point, online, continuous monitoring of icing thickness at the micrometer and millimeter level on the surfaces of objects such as wind turbine blades, aircraft, and power transmission lines. It is suitable for multi-point deployment on critical components such as aircraft wings and wind turbine blades, achieving comprehensive perception of icing conditions over large areas.

[0089] It is understood that the above specific description of this utility model is only used to illustrate this utility model and is not limited to the technical solutions described in the embodiments of this utility model. Those skilled in the art should understand that modifications or equivalent substitutions can still be made to this utility model to achieve the same technical effect; as long as the use needs are met, they are all within the protection scope of this utility model.

Claims

1. An icing sensor, comprising a silicon substrate (15), characterized in that... A groove is provided in the middle of the upper end of the silicon substrate (15), and a flat film (19) is fixed on the upper end of the silicon substrate (15). A cavity (20) is formed between the flat film (19) and the groove area of ​​the silicon substrate (15). A driving electrode and a detection electrode are provided on the silicon substrate (15) inside the cavity (20). The flat film (19) is a common electrode. The common electrode forms a capacitive coupling structure with the driving electrode and the detection electrode. The capacitance between the detection electrode and the common electrode is the detection capacitance.

2. The icing sensor according to claim 1, characterized in that... The cavity (20) is provided with a dielectric layer (16), which covers the upper ends of the driving electrode and the detection electrode.

3. The icing sensor according to claim 1, characterized in that... The flat film (19) is a diffused silicon layer.

4. The icing sensor according to claim 1, characterized in that... The driving electrode is located in the center of the silicon substrate (15) inside the cavity (20), and the detection electrode surrounds the driving electrode.

5. The icing sensor according to claim 1, characterized in that... Both the detection electrode and the driving electrode include two or more ring electrodes, forming a multi-ring detection structure.

6. The icing sensor according to claim 1, characterized in that... Both the detection electrode and the driving electrode include two ring electrodes. The inner ring electrode (5) and the outer ring electrode (6) of the detection electrode are respectively provided with a driving electrode through-hole (12) on one side. The inner ring electrode (5) and the outer ring electrode (6) of the detection electrode on both sides of the driving electrode through-hole (12) are connected by a horizontal strip detection electrode (1). The inner annular electrode (4) of the driving electrode away from the driving electrode through-hole (12) side and the outer annular electrode (7) of the driving electrode are respectively provided with a first opening (11). The inner annular electrode (4) of the driving electrode and the outer annular electrode (7) of the driving electrode on both sides of the first opening (11) are connected by a short horizontal strip driving electrode (8). The driving electrodes passing through the driving electrode through-hole (12) are two parallel long horizontal strip driving electrodes (2). The outer ring electrode (7) of the driving electrode away from the first opening (11) is provided with a second opening (13). The outer ring electrode (7) of the driving electrode on both sides of the second opening (13) is connected to the inner end of a long horizontal strip driving electrode (2). The outer ends of the two long horizontal strip driving electrodes (2) are connected to the driving electrode lead wire (3). The outer ring electrode (6) of the detection electrode away from the drive electrode through-hole (12) is provided with a third opening (14). The outer ring electrode (6) of the detection electrode on both sides of the third opening (14) is connected to the inner end of a long horizontal strip detection electrode (9). The outer ends of the two long horizontal strip detection electrodes (9) are connected to the detection electrode lead wire (10).

7. The icing sensor according to claim 6, characterized in that... The widths of the annular electrode, the horizontal strip detection electrode (1), the short horizontal strip driving electrode (8), the long horizontal strip driving electrode (2), the driving electrode lead (3), the long horizontal strip detection electrode (9), the detection electrode lead (10), the distance between the two long horizontal strip driving electrodes (2), the distance between the inner and outer annular electrodes, the distance between the two short horizontal strip driving electrodes (8), and the distance between the two long horizontal strip detection electrodes (9) are all 20 micrometers.

8. The icing sensor according to claim 1, characterized in that... The sensor has a surface protective film (21).

9. The icing sensor according to claim 1, characterized in that... Drainage grooves (17) are provided on the flat membrane (19) on the outer periphery of the cavity (20).

10. The icing sensor according to claim 1, characterized in that... The upper sides of the flat membrane (19) on the inner side of the drainage ditch (17) on the outer periphery of the cavity (20) are respectively provided with a driving electrode connection part and a detection electrode connection part, and a common electrode connection part is provided in the middle of the flat membrane (19).

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