Cleaning method and equipment for improving cleanliness of solid surface

Abstract

The invention discloses a cleaning method and equipment for improving the cleanliness of a solid surface. The cleaning method comprises the steps that a cleaning medium containing a cleaning liquid and a gas mixture is injected into a cleaning tank, gas exists in the cleaning medium in the form of micro-nano bubbles, the concentration of the micro-nano bubbles is 106-1012 / L, and the pressure of the gas is 0.01-2.00 MPa; ultrasonic waves with the frequency range of 1 kHz to 1 MHz are applied into the cleaning tank through a multi-frequency ultrasonic wave generating device; and the cleaning medium is adjusted to circularly flow in the cleaning tank so as to clean the surface of the solid. According to the solid surface cleaning method combining the micro-nano bubbles and the ultrasonic technology, the cleaning efficiency and effect are remarkably improved by optimizing generation, distribution and stability of the bubbles and accurately controlling interaction between ultrasonic waves and the bubbles.

Description

Technical Field

[0001] The present application relates to the field of cleaning technology, and in particular to a cleaning method and equipment for improving the cleanliness of a solid surface. Background Art

[0002] In modern industry, cleaning technology of solid surfaces plays a vital role, especially in the fields of microelectronics, optics, medical devices and other precision manufacturing. The removal of surface contaminants not only affects the appearance and function of the product, but is also directly related to the quality and performance of the product. With the continuous development of manufacturing technology, the standards for surface cleanliness are getting higher and higher, which puts higher requirements on cleaning technology. Although traditional surface cleaning methods can meet industrial needs to a certain extent, they are often difficult to cope with the growing demand for high-precision cleaning, especially when dealing with tiny particles, complex contaminants and precision surfaces. The effectiveness and efficiency of existing methods are significantly restricted. With the continuous advancement of science and technology, especially the application of nanotechnology, micro-nano bubble technology, as a new type of surface cleaning method, has gradually attracted widespread attention from academia and industry. This technology achieves surface cleaning by generating extremely small bubbles and utilizing their unique physical properties, and has great application potential.

[0003] At present, common surface cleaning technologies include manual cleaning, chemical cleaning, mechanical friction cleaning and ultrasonic cleaning. Although the manual cleaning method is easy to operate, it has poor removal effect on tiny pollutants and is easy to introduce secondary pollution during the cleaning process, which cannot meet the requirements of modern precision manufacturing. Chemical cleaning methods mainly remove pollutants by using solvents or other chemical reagents, which are suitable for removing pollutants such as grease and dust. However, chemical cleaning methods usually have potential hazards to the environment and the health of operators, and in some cases, chemical reagents may cause damage to the cleaned surface. Mechanical friction cleaning relies on physical contact to remove pollutants, but this method cannot effectively remove tiny particles and may cause scratches or other damage to the surface. Ultrasonic cleaning uses bubbles generated by high-frequency sound waves to remove surface pollutants. This method performs well in removing tiny particles and is particularly suitable for cleaning micro or complex surfaces. However, ultrasonic cleaning still has some limitations, especially in terms of the unevenness of bubble generation and distribution, the stability of bubbles, etc., and it is still difficult to meet the cleaning needs of higher precision and higher efficiency.

[0004] With the development of micro-nano bubble technology, it has gradually shown its unique advantages in the field of cleaning. Micro-nano bubbles are bubbles with a diameter ranging from tens of nanometers to several microns, with extremely high surface activity and strong kinetic effects. Compared with traditional bubbles, micro-nano bubbles have a larger specific surface area, stronger surface energy and longer residence time, which makes it show unique advantages in the cleaning and decontamination process. Micro-nano bubbles can be evenly distributed in the liquid, produce a strong physical effect, and can effectively remove the attachments on the solid surface, especially when dealing with small pollutants that are difficult to remove. It shows excellent results. In addition, micro-nano bubbles also have strong penetration ability and can penetrate into complex surface structures to remove pollutants that are difficult to reach. Therefore, micro-nano bubble technology has shown broad application prospects in the fields of surface cleaning, sewage treatment, medical device cleaning, etc. Although micro-nano bubble technology has significant advantages, it still faces some technical difficulties in practical applications. At present, the generation technology and control methods of micro-nano bubbles still have certain limitations, especially in terms of the uniformity, stability and controllability of bubbles. Summary of the invention

[0005] The main technical problem solved by the present application is to provide a cleaning method and equipment for improving the cleanliness of solid surfaces, which can improve the cleaning efficiency and effect.

[0006] In order to solve the above technical problems, a technical solution adopted in the present application is: to provide a cleaning method for improving the cleanliness of a solid surface, the cleaning method comprising: injecting a cleaning medium comprising a cleaning liquid and a gas mixture into a cleaning tank, the gas being present in the cleaning medium in the form of micro-nano bubbles, the concentration of the micro-nano bubbles being 106-1012 / L, and the pressure of the gas being 0.01-2.00 MPa; applying ultrasonic waves with a frequency range of 1 kHz to 1 MHz into the cleaning tank using a multi-frequency ultrasonic generator; and adjusting the cleaning medium to circulate in the cleaning tank to clean the solid surface.

[0007] In one embodiment, the multi-frequency ultrasonic generating device includes an ultrasonic generator and an ultrasonic vibration plate, and the acoustic Reynolds number of the cleaning medium flowing through the ultrasonic vibration plate is 50-500.

[0008] In one embodiment, the sound pressure on the surface of the ultrasonic vibration plate is 1-20 mV.

[0009] In one embodiment, the surface of the ultrasonic vibration plate is flat, spherical or corrugated, and its roughness does not exceed 1 micrometer.

[0010] In one embodiment, the flow velocity of the cleaning medium is 0.01-2.00 m / s.

[0011] In one embodiment, the angle between the flow direction of the cleaning medium in the cleaning tank and the surface of the ultrasonic vibration plate is 0-90°.

[0012] In one embodiment, the amplitude of the ultrasonic wave is in the range of 10-100 microns.

[0013] In one embodiment, the ultrasonic generator is used to adjust the operating frequency and / or power in real time according to the bubble distribution and fluid characteristics of the cleaning medium.

[0014] In one embodiment, the acoustic field formed in the cleaning tank is a dynamically adjusted uniform acoustic field.

[0015] In one embodiment, the cleaning medium further includes a surface tension regulator, which is used to reduce the surface tension of the solution. The concentration of the surface tension regulator is 0.001-1.0 wt %.

[0016] In one embodiment, the surface tension modifier comprises a surfactant.

[0017] In one embodiment, the cleaning method further comprises: controlling the temperature in the cleaning tank to be within the range of 0-100°C.

[0018] In one embodiment, the gas includes one or more of oxygen, ozone, nitrogen, carbon dioxide or an inert gas.

[0019] In one embodiment, the pressure of the gas is 1.0-1.5 Mpa; the temperature in the cleaning tank is 30-35°C; 0.05-0.08 wt% of a surfactant is added to the cleaning medium; the frequency of the ultrasonic wave is 40-80 kH; the flow rate of the cleaning medium is 0.01-1.00 m / s, and the gas is one or more of oxygen, ozone, and nitrogen.

[0020] In one embodiment, the micro-nano bubbles come from a micro-nano bubble generating device, which generates micro-nano bubbles by pressure dissolution, microporous aeration, membrane aeration, electrolysis, hydrodynamic cavitation, rotational flow, turbulent static mixing, ejector nozzle or hammer mill rotation.

[0021] In one embodiment, the cleaning method further comprises: using deionized water to rinse the solid surface after ultrasonic cleaning for a second time, and the flow rate of the deionized water is 0.5-2.0 m / s.

[0022] In one embodiment, after the cleaning process is completed, the effective components in the liquid in the cleaning tank are recovered and reused through membrane separation technology, and the effective components include one or more of acids, alkalis, functional agents, and micro-nano bubbles.

[0023] In one embodiment, the cleaning method is used to clean electronic components, optical lenses, silicon wafer surfaces, quartz surfaces, food surfaces, cultural relic surfaces, precision mechanical parts, and medical device surfaces.

[0024] In order to solve the above technical problems, a technical solution adopted in this application is: to provide a cleaning device for improving the cleanliness of solid surfaces, the cleaning device includes a cleaning tank, a multi-frequency ultrasonic generator and a reflux device. The cleaning tank is used to accommodate cleaning media and devices to be cleaned, the cleaning tank includes a medium inlet and a medium outlet, the medium inlet is used to access the cleaning medium, the cleaning medium includes a mixture of cleaning liquid and gas, the gas exists in the cleaning medium in the form of micro-nano bubbles, the concentration of micro-nano bubbles is 106-1012 / L, and the pressure of the gas is 0.01-2.00 MPa; the multi-frequency ultrasonic generator is arranged on the inner wall of the cleaning tank, and is used to apply ultrasonic waves with a frequency of 1 kHz to 1 MHz into the cleaning tank; the reflux device includes a reflux pipe, the reflux pipe is connected to the medium inlet and the medium outlet respectively, and the reflux device is used to adjust the circulation of the cleaning medium in the cleaning tank to clean the solid surface.

[0025] In one embodiment, the multi-frequency ultrasonic generating device includes an ultrasonic generator and an ultrasonic vibration plate. The surface morphology of the ultrasonic vibration plate is flat, spherical or corrugated, and its surface roughness does not exceed 1 micron; the amplitude range of the ultrasonic wave is 10-100 microns.

[0026] In one embodiment, the reflux device further comprises a fluid pump, which is a fluid pump with adjustable flow rate, and the fluid pump is used to control the flow velocity of the cleaning medium within the range of 0.01 to 2 m / s.

[0027] In one embodiment, the cleaning equipment also includes a micro-nano bubble generating device, which generates micro-nano bubbles by pressure dissolution, microporous aeration, membrane aeration, electrolysis, hydraulic cavitation, rotational flow, turbulent static mixing, ejector nozzle or hammer mill rotation.

[0028] In one embodiment, the cleaning device further comprises a temperature control system, wherein the temperature control system comprises a temperature sensor and a heating / cooling unit, and is used to control the temperature of the cleaning medium within a range of 0 to 100°C.

[0029] In one embodiment, the cleaning device also includes a control unit, which is electrically connected to the micro-nano bubble generating device, the ultrasonic generator, the reflux device and the temperature control system, and is used to monitor the micro-nano bubble concentration, the sound field distribution and the temperature parameters, and automatically adjust the equipment operating parameters based on the monitoring data.

[0030] In one embodiment, the cleaning device further comprises a deionized water system, and the deionized water system is used for secondary rinsing of the solid surface after ultrasonic cleaning, and the flow rate of the deionized water is 0.5-2.0 m / s.

[0031] In one embodiment, the cleaning equipment further comprises a membrane separation device, which is used to recycle and reuse effective components in the liquid in the cleaning tank, wherein the effective components include one or more of acids, alkalis, functional agents, and micro-nano bubbles.

[0032] In one embodiment, the cleaning device further comprises a drying device, which is used to dry the cleaned solid material, with the temperature being controlled at 60-80° C., the vacuum degree being controlled at -0.08 to -0.1 MPa, and the drying time being 6 to 12 hours.

[0033] In one embodiment, the device is used to clean electronic components, optical lenses, silicon wafer surfaces, quartz surfaces, food surfaces, cultural relic surfaces, precision mechanical parts, and medical device surfaces.

[0034] The above description is only an overview of the technical solution of the present application. In order to more clearly understand the technical means of the present application, it can be implemented in accordance with the contents of the specification. In order to make the above and other purposes, features and advantages of the present application more obvious and easy to understand, the specific implementation methods of the present application are listed below. BRIEF DESCRIPTION OF THE DRAWINGS

[0035] In order to more clearly illustrate the technical solutions in the embodiments of the present application, the drawings required for use in the description of the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present application. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying any creative work.

[0036] Figure 1 A schematic cross-sectional structure diagram of a cleaning device according to one or more embodiments of the present application; Figure 2 This is a schematic cross-sectional structure diagram of an ultrasonic generator according to one or more embodiments of the present application; Figure 3 This is a schematic diagram of an array of ultrasonic generators according to one or more embodiments of the present application; Figure 4 A schematic diagram of an ultrasonic sound field according to one or more embodiments of the present application; Figure 5 is another ultrasonic sound field schematic diagram according to one or more embodiments of the present application; Figure 6 A schematic plan view of an ultrasonic vibration plate according to one or more embodiments of the present application; Figure 7 It is a schematic diagram of the three-dimensional structure of a cleaning device according to one or more embodiments of the present application. DETAILED DESCRIPTION

[0037] In order to make the purpose, technical solution and effect of the present application clearer and more specific, the following will describe the embodiments of the technical solution of the present application in detail with reference to the accompanying drawings. The following embodiments are only used to more clearly illustrate the technical solution of the present application, and are therefore only used as examples, and cannot be used to limit the scope of protection of the present application.

[0038] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by technicians in the technical field to which this application belongs; the terms used herein are only for the purpose of describing specific embodiments and are not intended to limit this application; the terms "including" and "having" in the specification and claims of this application and the above-mentioned figure descriptions and any variations thereof are intended to cover non-exclusive inclusions.

[0039] In the description of the embodiments of the present application, the technical terms "first", "second", etc. are only used to distinguish different objects, and cannot be understood as indicating or implying relative importance or implicitly indicating the number, specific order or primary and secondary relationship of the indicated technical features. In the description of the embodiments of the present application, the term "multiple" refers to more than two (including two), similarly, "multiple groups" refers to more than two (including two groups), and "multiple pieces" refers to more than two (including two pieces), unless otherwise clearly and specifically defined.

[0040] Reference to "embodiments" herein means that a particular feature, structure, or characteristic described in conjunction with the embodiments may be included in at least one embodiment of the present application. The appearance of the phrase in various locations in the specification does not necessarily refer to the same embodiment, nor is it an independent or alternative embodiment that is mutually exclusive with other embodiments. It is explicitly and implicitly understood by those skilled in the art that the embodiments described herein may be combined with other embodiments.

[0041] In the description of the embodiments of the present application, the term "and / or" is only a description of the association relationship of the associated objects, indicating that there may be three relationships. For example, A and / or B can represent: A exists alone, A and B exist at the same time, and B exists alone. In addition, the character " / " in this article generally indicates that the associated objects before and after are in an "or" relationship.

[0042] Amounts, ratios and other numerical values ​​are presented herein in a range format. It should be understood that such a range format is for convenience and brevity and should be flexibly interpreted to include not only the values ​​explicitly specified as range limits, but also all individual values ​​or sub-ranges encompassed within the range, as if each value and sub-range were explicitly specified.

[0043] If there is no special explanation, all steps of the present application can be performed sequentially, randomly, or in parallel, preferably sequentially. For example, the method includes steps (a) and (b), indicating that the method may include steps (a) and (b) performed sequentially, or may include steps (b) and (a) performed sequentially, or may be steps (a) and (b) performed simultaneously in parallel. For example, the method may also include step (c), indicating that step (c) may be added to the method in any order, for example, the method may include steps (a), (b) and (c), or may include steps (a), (c) and (b), or may include steps (c), (a) and (b), etc.

[0044] In recent years, more and more researchers have proposed combining ultrasonic technology with micro-nano bubble technology to further improve cleaning efficiency and effectiveness. Ultrasonic technology excites microbubbles in liquids through high-frequency sound waves, generating strong local impact and shear forces. These physical effects can effectively remove pollutants from solid surfaces, thereby improving cleaning effects. The synergistic effect of ultrasonic waves and micro-nano bubbles can make the dynamic behavior of bubbles more intense and enhance their decontamination ability. However, the existing technology combining ultrasonic waves with micro-nano bubbles still has some problems. For example, the generation, distribution and stability of bubbles are difficult to accurately control, and the interaction between ultrasonic parameters such as frequency and power and bubbles has not yet been effectively regulated.

[0045] Among them, the existing micro-nano bubble generation methods usually rely on high-pressure gas dissolution, bubble generators, static mixers and other equipment to achieve bubble generation, but these methods often make it difficult to ensure the uniform distribution of bubbles in the liquid, and the size, concentration and stability of the bubbles are also difficult to accurately control. These factors limit the application effect of micro-nano bubble technology in the cleaning process, especially in applications with high requirements such as high-precision cleaning and removal of complex pollutants. The stability and repeatability of the cleaning effect are still a problem that needs to be solved urgently. This makes it difficult for the cleaning efficiency and accuracy to reach the expected level. Therefore, how to optimize the generation and movement of bubbles and accurately control the interaction between ultrasound and bubbles to achieve efficient and accurate surface cleaning is a key problem that needs to be solved in the current micro-nano bubble cleaning technology. The development of more efficient and accurate micro-nano bubble generation and control technology, as well as the further optimization of the synergistic effect of ultrasound and micro-nano bubbles, are still the key to promoting the development of this field.

[0046] This application overcomes the various deficiencies in the prior art by innovatively optimizing the generation, distribution and stability of micro-nano bubbles, and combining the precise control of ultrasonic technology, thereby providing a more efficient and accurate solution in the field of surface cleaning. Through means such as multi-frequency resonance and dynamic fluid control, this application can achieve uniform generation and precise control of bubbles, and give full play to the synergistic effect of ultrasonic waves and micro-nano bubbles to significantly improve the cleaning effect. This technology not only solves the problems of unstable bubbles and uneven cleaning effects in the prior art, but also ensures that the surface is not damaged during the cleaning process, meeting the stringent requirements of modern high-end manufacturing industries for surface cleanliness.

[0047] In one embodiment, the present application provides a cleaning method for improving the cleanliness of a solid surface, the method comprising: injecting a cleaning medium comprising a cleaning liquid and a gas mixture into a cleaning tank, the cleaning gas being present in the cleaning medium in the form of micro-nano bubbles, the concentration of the micro-nano bubbles being 106 to 1012 / L, and the pressure of the gas being 0.01 to 2.00 MPa; applying ultrasonic waves with a frequency range of 1 kHz to 1 MHz into the cleaning tank using a multi-frequency ultrasonic generator; and adjusting the cleaning medium to circulate in the cleaning tank to clean the solid surface.

[0048] Among them, the selection of cleaning liquid should be based on the material and contaminant characteristics of the solid surface to be cleaned to ensure the cleaning effect and avoid damage to the substrate, that is, select a cleaning liquid suitable for the cleaning object and contamination type, such as ultrapure water or environmentally friendly cleaning liquid, and add it to the ultrasonic cleaning tank.

[0049] The cleaning gas is mixed with the cleaning liquid in the form of micro-nano bubbles, or in other words, the cleaning gas is present in the cleaning medium in the form of micro-nano bubbles. The gas can be introduced into the cleaning liquid by a micro-nano bubble generator, and a forced mixing method is adopted to fully contact with the cleaning liquid to generate micro-nano bubbles with a particle size range of 10 to 200 nanometers. The gas can be selected from any one or more combinations of oxygen, ozone, nitrogen, carbon dioxide or inert gas to enhance cleaning performance. The micro-nano bubble generator adopts pressure dissolution, microporous aeration, membrane aeration, electrolysis, hydrodynamic cavitation, rotary flow, turbulent static mixing, ejector nozzle or hammer mill rotary method to generate the micro-nano bubbles.

[0050] In one embodiment, the concentration of the micro-nano bubbles is regulated within the range of 106 to 1012 / cm3, for example, 106 / cm3, 107 / cm8, 109 / cm3, 1010 / cm3, 1012 / cm3, etc. The injection pressure of the gas is maintained between 0.01 and 2.00 MPa, for example, 0.01 MPa, 0.05 MPa, 0.10 MPa, 0.30 MPa, 0.50 MPa, 0.80 MPa, 1.00 MPa, 1.30 MPa, 1.50 MPa, 1.80 MPa, 2.00 MPa, etc. This arrangement can make the micro-nano bubbles in the cleaning medium more stable and more evenly distributed, thereby enhancing the cleaning effect.

[0051] Furthermore, a multi-frequency ultrasonic generator is used to apply ultrasonic waves with a frequency range of 1 kHz to 1 MHz into the cleaning tank, for example, 1 kHz, 5 kHz, 10 kHz, 30 kHz, 50 kHz, 100 kHz, 300 kHz, 500 kHz, 800kHz, 1 MHz, etc., to generate high-frequency vibration and cavitation effect to achieve cleaning. At the same time, the cleaning medium is circulated in the cleaning tank through the water distribution pipe and the reflux system to form a stable flow field, so that the cleaning medium is fully in contact with the solid surface, thereby improving the cleaning efficiency.

[0052] In one embodiment, the multi-frequency ultrasonic generator includes an ultrasonic generator and an ultrasonic vibration plate. The application principle of the ultrasonic generator is that the high-frequency oscillation signal emitted by the ultrasonic generator is converted into a high-frequency mechanical oscillation by a transducer and propagated to the cleaning medium, and the ultrasonic wave radiates forward in the cleaning medium in a sparse and dense manner, causing the cleaning medium to flow and generate tens of thousands of tiny bubbles. The tiny bubbles (cavitation nuclei) in the cleaning medium vibrate under the action of the sound field. When the sound pressure reaches a certain value, the bubbles grow rapidly and then suddenly close. When the bubbles close, shock waves are generated, and thousands of atmospheric pressures are generated around them, destroying insoluble dirt and dispersing them in the cleaning liquid. When the group particles are wrapped in oil and adhere to the surface of the cleaning object, the oil is emulsified and the solid particles are separated, thereby achieving the purpose of purifying the surface of the cleaning object.

[0053] The ultrasonic generator and the ultrasonic vibration plate are arranged in a split manner and connected by a line. The ultrasonic generator is placed in the cleaning tank, and the ultrasonic vibration plate can be arranged on the bottom, side or top of the cleaning tank according to the needs of the ultrasonic radiation surface.

[0054] In one embodiment, the vibration surface of the ultrasonic vibration plate can be flat, spherical or corrugated, and its surface roughness does not exceed 1 micron to optimize the sound field distribution and make the sound field distribution more uniform.

[0055] The ultrasonic generator is used to adjust the operating frequency and / or power in real time according to the bubble distribution and fluid characteristics of the cleaning medium. The ultrasonic frequency and amplitude can be dynamically adjusted according to the material and contamination type of the cleaning object to ensure the best cleaning effect.

[0056] In one embodiment, the amplitude of the ultrasonic wave ranges from 10 to 100 microns, such as 10 microns, 30 microns, 50 microns, 80 microns, 100 microns, etc. The sound pressure on the surface of the ultrasonic vibration plate is 1-20 mV, such as 1 mV, 3 mV, 5 mV, 8 mV, 10 mV, 12 mV, 15 mV, 18 mV, 20 mV, etc. The sound field formed in the cleaning tank is a dynamically adjusted uniform sound field. This setting can reduce ultrasonic energy loss and enhance the cleaning effect.

[0057] This technology achieves uniform energy distribution by dynamically adjusting the ultrasonic sound field. The core is based on a multi-frequency phase array control and real-time feedback system, which adaptively adjusts the transducer parameters to suppress standing waves and eliminate cleaning blind spots. It combines the vortex sound field to generate a three-dimensional flow state to enhance the cavitation effect, and uses time-space energy modulation to synchronize the movement of the workpiece, significantly improving the cleaning coverage uniformity of the surface of complex structures. On the premise of maintaining the integrity of the material, it breaks through the bottleneck of traditional ultrasonic cleaning for high aspect ratios and fine structures, and achieves high-efficiency and low-cost precision cleaning.

[0058] The cleaning medium is circulated in the cleaning tank through the water distribution pipe and the reflux system to form a stable flow field. The formation of the flow field adjusts the flow rate and flow rate to make the cleaning medium fully contact with the solid surface and improve the cleaning efficiency.

[0059] In one embodiment, the flow velocity of the cleaning medium is controlled between 0.01 and 2 m / s, for example, 0.01 m / s, 0.03 m / s, 0.05 m / s, 0.08 m / s, 0.10 m / s, 0.15 m / s, 0.20 m / s, 0.50 m / s, 0.80 m / s, 1.00 m / s, 1.20 m / s, 1.50 m / s, 1.80 m / s, 2.00 m / s, etc., to ensure uniform distribution of the cleaning medium and enhance the cleaning effect.

[0060] In one embodiment, the flow direction of the cleaning medium in the cleaning tank is at an angle of 0 to 90 degrees to the surface of the ultrasonic vibration plate. This setting can achieve efficient cleaning by maintaining an optimized Reynolds number through mechanisms such as fluid dynamics optimization (0° parallel flow prolongs contact time, 90° vertical impact increases shear force by 60%), synergistic enhancement of cavitation effect (cavitation bubble density doubles when tilted at 30-60°), three-dimensional spiral flow coverage (reducing blind spots by 72%), and thermodynamic synergy (45° impact heating accelerates reaction), combined with a dynamic angle adjustment system.

[0061] In one embodiment, the acoustic Reynolds number of the cleaning medium flowing through the ultrasonic vibration plate is 50 to 500, for example, it can be 50, 80, 100, 150, 200, 230, 280, 320, 370, 410, 460, 500, etc. This setting can achieve multi-level synergy: the low Reynolds number interval uses fluid viscosity to enhance the cavitation bubble collapse energy, targeted removal of nano-scale pollutants and significantly reduce the risk of cavitation; the middle section accelerates molecular diffusion through the flow field-acoustic field resonance effect to achieve extremely high surface contact efficiency; the high section generates high-speed microjets to peel off micron-scale particles, while combining viscous dissipation to accurately control temperature and protect heat-sensitive materials; the dynamic adjustment mechanism can simultaneously remove multi-scale pollutants and significantly improve cleaning uniformity. When this technology is applied to the cleaning of precision devices, it can not only achieve high-intensity pollutant removal, but also ensure the integrity of the substrate, while significantly reducing energy consumption, providing innovative solutions for efficient cleaning of complex structures. 。

[0062] In one embodiment, the cleaning medium further includes a surface tension regulator, which is used to reduce the surface tension of the solution, and the concentration of the surface tension regulator is 0.001 to 1.0 wt%, for example, 0.001 wt%, 0.002 wt%, 0.005 wt%, 0.010 wt%, 0.030 wt%, 0.050 wt%, 0.080 wt%, 0.100 wt%, 0.300 wt%, 0.500 wt%, 0.800 wt%, 1.000 wt%, etc.; optionally, the surface tension regulator includes a surfactant. The surface tension regulator can adjust the surface tension of the cleaning medium, prevent bubbles from agglomerating, and improve the cleaning effect.

[0063] In one embodiment, the cleaning method further comprises controlling the temperature in the cleaning tank within a range of 0 to 100° C. The temperature of the medium in the cleaning tank is controlled within a range of 0 to 100° C. by a temperature control system, for example, 5° C., 10° C., 15° C., 25° C., 35° C., 50° C., 80° C., 100° C., etc. The temperature control system comprises a temperature sensor and a heating / cooling unit, which can monitor and adjust the temperature of the cleaning liquid in real time, enhance the cleaning efficiency and prevent excessive accumulation and rupture of bubbles.

[0064] In one embodiment, the cleaning method further includes real-time monitoring of micro-nano bubble concentration, flow field distribution and temperature parameters by a control unit, and automatically adjusting operating parameters such as ultrasonic frequency, amplitude and fluid flow rate based on the monitoring data to ensure the stability and efficiency of the cleaning process.

[0065] In one embodiment, the cleaning gas is oxygen, and the pressure of the gas is 1 Mpa; the temperature in the cleaning tank is 30° C.; 0.05 wt % of a surfactant is added to the cleaning medium; the frequency of the ultrasonic wave is 80 kH; and the flow rate of the cleaning medium is 0.01 m / s.

[0066] In one embodiment, the cleaning gas is oxygen, and the pressure of the gas is 1 Mpa; the temperature in the cleaning tank is 30° C.; 0.05 wt % of a surfactant is added to the cleaning medium; the frequency of the ultrasonic wave is 80 kH; and the flow rate of the cleaning medium is 1.00 m / s.

[0067] In one embodiment, the cleaning gas is ozone, and the pressure of the gas is 1 MPa; the temperature in the cleaning tank is 30° C.; 0.05 wt % of a surfactant is added to the cleaning medium; the frequency of the ultrasonic wave is 80 kH; and the flow rate of the cleaning medium is 0.01 m / s.

[0068] In one embodiment, the cleaning gas is nitrogen, and the pressure of the gas is 1 Mpa; the temperature in the cleaning tank is 30° C.; 0.05 wt % of a surfactant is added to the cleaning medium; the frequency of the ultrasonic wave is 80 kH; and the flow rate of the cleaning medium is 0.01 m / s.

[0069] In one embodiment, the cleaning method further comprises, after the ultrasonic cleaning is completed, using deionized water to perform a secondary rinse on the ultrasonic solid surface to remove residual impurities. The flow rate of the rinse liquid (deionized water) is controlled within the range of 0.5 to 2 m / s to ensure that the residues are completely removed. Subsequently, the cleaned solid material is dried in a drying device at a certain temperature and vacuum to obtain a clean product.

[0070] In one embodiment, the cleaning method also includes recovering and reusing effective ingredients in the cleaning medium through membrane separation technology, the effective ingredients including acids, alkalis, functional agents, micro-nano bubbles, etc., and reusing the recovered effective ingredients for the next round of cleaning process to improve resource utilization and reduce operating costs.

[0071] The above-mentioned solid surface cleaning method combining micro-nano bubbles and ultrasonic technology provided by the present application aims to significantly improve the cleaning efficiency and effect by optimizing the generation, distribution and stability of bubbles and accurately controlling the interaction between ultrasonic waves and bubbles. The method is particularly suitable for efficient and uniform cleaning of precision surfaces such as electronic components, optical lenses, silicon wafer surfaces, quartz surfaces, food surfaces, cultural relics surfaces, precision mechanical parts and medical devices, overcoming the problems of uneven bubble generation, poor stability and inaccurate ultrasonic control in the prior art.

[0072] See also Figure 1 , Figure 1The cross-sectional structure diagram of a cleaning device according to one or more embodiments of the present application. The present application provides a cleaning device for improving the cleanliness of a solid surface, the cleaning device comprising a cleaning tank 10, an ultrasonic generator 20 and a reflux device 30, wherein: The cleaning tank 10 is used to accommodate cleaning medium and devices to be cleaned. The cleaning tank 10 includes a medium inlet 101 and a medium outlet 102. The medium inlet 101 is used to connect the cleaning medium. The cleaning medium includes a mixture of cleaning liquid and gas. The cleaning gas exists in the cleaning medium in the form of micro-nano bubbles. The concentration of the micro-nano bubbles is 106-1012 / L, and the pressure of the gas is 0.01-2.00 MPa.

[0073] The multi-frequency ultrasonic wave generator 20 is disposed on the inner wall of the cleaning tank 10 , and is used to apply ultrasonic waves with a frequency of 1 kHz-1 MHz into the cleaning tank 10 .

[0074] The reflux device 30 includes a reflux pipe 301 , which is connected to the medium inlet 101 and the medium outlet 102 , respectively. The reflux device 30 is used to adjust the circulation of the cleaning medium in the cleaning tank 10 to clean the solid surface.

[0075] In one embodiment, the inner surface of the cleaning tank 10 is covered with an anti-corrosion coating to extend the service life of the cleaning tank 10 and maintain the stability of the cleaning process. The material of the cleaning tank 10 can be selected from high-strength titanium alloy or corrosion-resistant stainless steel to adapt to different cleaning environments and media.

[0076] In one embodiment, the multi-frequency ultrasonic generating device 20 includes an ultrasonic generator 201 and an ultrasonic vibration plate 202 .

[0077] The application principle of the multi-frequency ultrasonic generating device 20 is that the high-frequency oscillation signal emitted by the ultrasonic generator is converted into high-frequency mechanical oscillation by the transducer and propagated to the cleaning medium. The ultrasonic wave radiates forward in a sparse and dense manner in the cleaning medium, causing the liquid to flow and generate tens of thousands of tiny bubbles. The tiny bubbles (cavitation nuclei) in the liquid vibrate under the action of the sound field. When the sound pressure reaches a certain value, the bubbles grow rapidly and then suddenly close. When the bubbles close, shock waves are generated, and thousands of atmospheric pressures are generated around them, destroying insoluble dirt and dispersing them in the cleaning liquid. When the group particles are wrapped in oil and adhere to the surface of the cleaning object, the oil is emulsified and the solid particles are detached, thereby achieving the purpose of purifying the surface of the cleaning object.

[0078] The ultrasonic generator 201 and the ultrasonic vibration plate 202 may adopt a split structure, and the ultrasonic vibration plate 202 and the ultrasonic generator 201 are connected by a high-frequency line with a socket. The split structure makes use and maintenance more convenient.

[0079] The ultrasonic vibration plate 202 can be arranged on the bottom, side or top of the cleaning tank as required. The installation arrangement is flexible. The ultrasonic vibration plate 202 can be arranged inside the cleaning tank in a single point arrangement, a linear arrangement, a random arrangement, an array arrangement, a phased array arrangement, etc.

[0080] The surface of the ultrasonic vibration plate 202 is flat, spherical or corrugated, and its surface roughness does not exceed 1 micron.

[0081] See also Figure 2 and Figure 3 , Figure 2 is a schematic cross-sectional structure diagram of an ultrasonic generator according to one or more embodiments of the present application, Figure 3 Schematic diagram of an array of ultrasonic generators according to one or more embodiments of the present application.

[0082] The ultrasonic generator 201 includes a transducer, an acoustic lens, a filling medium, a housing, and an electrical interface. The transducer includes a backing material 2011 and a piezoelectric material 2012. The piezoelectric material 2012 is the core part of the transducer and is used to convert electrical energy into acoustic waves, or convert acoustic waves into electrical energy. The backing material 2011 is used to absorb the back ultrasonic waves generated by the piezoelectric material to prevent the reflected waves from interfering with the forward waves. The transducer also includes an electrode 2013, a matching layer 2014, and an acoustic coupling layer 2015. The electrode 2013 is usually a conductive layer connected to the piezoelectric material 2012 and is used to apply an electric field or receive a piezoelectric response signal. The matching layer 2014 is located between the piezoelectric material 2012 and the filling medium to reduce the mismatch of acoustic impedance and enhance the efficiency of acoustic wave transmission. The acoustic coupling layer 2015 is also called an adhesive layer, which is used to firmly combine the components such as the piezoelectric material 2012 and the matching layer 2014, while minimizing the energy loss of the acoustic waves.

[0083] The acoustic lens 2016 is usually arc-shaped and is used to focus or adjust the propagation path of ultrasonic waves.

[0084] Filling medium 2017 is a material filled between the acoustic lens and other components to optimize the propagation of sound waves.

[0085] The housing 2018 is used to protect the internal components and provide mechanical support, thereby providing protection and sealing for the entire transducer.

[0086] The electrical interface 2019 is used to connect to an external power source or a signal processing device to input an excitation signal or output a detection signal.

[0087] The ultrasonic array includes an ultrasonic unit array 201-1, a dedicated integrated circuit 201-2, a dematching layer 201-3 and an ultrasonic generator array unit 201-4. Among them, in the ultrasonic generator, the main purpose of the ultrasonic unit array 201-1 is to optimize the energy transfer efficiency of the sound wave, reduce reflection and mismatch problems, and ensure that the propagation characteristics of the sound wave in the target medium meet expectations.

[0088] In addition, phased array technology can be applied to the cleaning field by precisely adjusting the sound field. For example, by adjusting the intensity and direction of the sound field, it is possible to achieve concentrated cleaning of a specific area, improving cleaning efficiency and effectiveness. In addition, acoustic levitation technology can be used to suspend and separate tiny particles, further optimizing the cleaning process.

[0089] See also Figure 4 and Figure 5 , Figure 4 This is a schematic diagram of an ultrasonic sound field according to one or more embodiments of the present application. Figure 5 Another ultrasonic sound field schematic diagram according to one or more embodiments of the present application. The figure shows a sound field cross section parallel to the plane linear transducer array at the edge of the near field region. The near field region refers to an area near the source of sound or electromagnetic waves, in which the propagation characteristics of the wave are different from those in the far field region. Specifically: Near the acoustic wave emission source (such as an ultrasonic transducer), the wavefront (wavefront) of the acoustic wave has not yet completely formed a plane wave or a spherical wave, the energy distribution of the wave is uneven, and the interference and diffraction effects of the wave are significant. In this area, the intensity and phase distribution of the acoustic wave are complex, and the closer to the emission source, the more obvious these effects are. Near the electromagnetic wave emission source (such as an antenna), the field distribution of the electromagnetic wave is also complex, the distribution of the electric field and the magnetic field is uneven, and the interference and diffraction effects of the wave are significant. In this area, the radiation pattern of the electromagnetic wave is different from that in the far field area.

[0090] The boundary between the near-field region and the far-field region usually depends on the wavelength and the size of the emitting source. For sound waves, the length of the near-field region is approximately the square of the diameter of the emitting source divided by the wavelength. For electromagnetic waves, the length of the near-field region is similar, depending on the size of the emitting source and the wavelength.

[0091] The ultrasonic wave generating device 20 has a dynamic adjustment function, and can adjust the frequency and amplitude of the ultrasonic wave in real time according to the bubble distribution and fluid characteristics of the cleaning medium, so as to optimize the interaction between the ultrasonic wave and the bubbles, thereby enhancing the cleaning effect.

[0092] The multi-frequency ultrasonic generating device is capable of applying ultrasonic waves with a frequency range of 1 kHz to 1 MHz and an amplitude range of 10 to 100 microns.

[0093] In one embodiment, the reflux device 30 includes a reflux pipe 301 and a fluid pump (not shown), the reflux pipe 301 is connected to the cleaning tank 10, and the reflux device 30 is used to circulate the cleaning medium in the cleaning tank 10 to form a stable flow field. The fluid pump can be a fluid pump with adjustable flow rate, which is used to control the fluid flow field in the cleaning tank. Among them, the flow velocity of the cleaning medium can be controlled in the range of 0.01 to 2 m / s. The formation of the flow field ensures that the liquid medium is evenly distributed by adjusting the flow velocity and flow rate, so that the liquid medium is fully in contact with the solid surface, thereby enhancing the cleaning effect and improving the cleaning efficiency.

[0094] The reflux system uses a Grundfos UP15-42F pump with variable frequency control function to ensure the stability of the flow field and the uniform distribution of the liquid medium. The reflux device 30 is used to control the flow direction of the cleaning medium in the cleaning tank 10 and the angle with the ultrasonic vibration plate 202 to be 0 to 90 degrees. In one embodiment, the cleaning device further comprises an input device, the input device comprises a micro-nano bubble generating device, the input device introduces gas into the cleaning liquid through the micro-nano bubble generating device, adopts a forced mixing method to fully contact with the cleaning liquid, generates micro-nano bubbles with a particle size range of 10 to 200 nanometers, and inputs the mixed cleaning medium into the cleaning tank. The micro-nano bubble generating device generates the micro-nano bubbles by pressure dissolution method, microporous aeration method, membrane aeration method, electrolysis method, hydraulic cavitation method, rotational flow method, turbulent static mixing method, ejector nozzle method or hammer mill rotation method.

[0095] In one embodiment, the cleaning device further comprises a temperature control system, which comprises a temperature sensor and a heating / cooling unit, for controlling the temperature of the cleaning liquid within a range of 0 to 100°C. The system can accurately adjust the temperature to prevent excessive accumulation and rupture of bubbles and improve cleaning efficiency. The accuracy of the temperature control module is controlled within ±0.5°C to ensure temperature stability and controllability.

[0096] In one embodiment, the cleaning device further comprises a control unit, which is electrically connected to the micro-nano bubble generator, the ultrasonic generator, the circulating water pipe and the temperature control system, and is used to monitor the bubble concentration, the acoustic field distribution and the temperature parameters, and automatically adjust the equipment operation parameters based on the monitoring data. The control unit adopts an artificial intelligence-based adjustment algorithm, which can optimize the ultrasonic frequency, amplitude and fluid flow rate in real time according to the cleaning object, so as to ensure the efficiency and stability of the cleaning process.

[0097] In one embodiment, the cleaning equipment further comprises a deionized water system, which is used for secondary rinsing after cleaning to ensure the final cleanliness of the surface of the solid material. The deionized water system adopts the Arium® series ultrapure water system of Sartorius of Germany to ensure the provision of high-quality ultrapure water and meet strict water quality requirements.

[0098] In one embodiment, the cleaning device further comprises a membrane separation device, which is used to recover micro-nano bubbles from the cleaning liquid after the cleaning process is completed. The device can separate bubbles with a diameter less than 200 nanometers and return them to the micro-nano bubble generating device to achieve bubble reuse, improve resource utilization, and reduce operating costs.

[0099] In one embodiment, the cleaning device further comprises a drying device, which is used to dry the cleaned solid material, with the temperature controlled at 60 to 80° C., the vacuum degree controlled at -0.08 to -0.1 MPa, and the drying time being 6 to 12 hours. The lining material of the drying device is made of stainless steel and DuPont PTFE to ensure durability and corrosion resistance.

[0100] The cleaning method and equipment of the present application are described in detail below in conjunction with specific embodiments.

[0101] 1. Sound pressure test and analysis In order to verify the effectiveness of the cleaning method provided in this application, the following experiments were conducted: Arrange 6 sampling points on an ultrasonic vibration plate (such as Figure 6 and 7 As shown, Figure 6 is a schematic plan view of an ultrasonic vibration plate according to one or more embodiments of the present application. Figure 7 ) is a schematic diagram of the three-dimensional structure of a cleaning device according to one or more embodiments of the present application, and the sound pressure values ​​are measured under different conditions.

[0102] Experimental steps: Ultrasound pressure testing without ventilation: Without any gas in the cleaning tank, the ultrasonic generator was started and the sound pressure values ​​were measured at different positions. The results showed that the sound pressure values ​​were relatively high, such as 20 mV, 40 mV, and 35 mV.

[0103] Ultrasonic sound pressure test under air flow conditions: Air was introduced into the cleaning tank at a gas flow rate of 320 mL / min for 10 minutes, 20 minutes, and 30 minutes. The results showed that the sound pressure value was significantly reduced. For example, under the conditions of 320 mL / min and 10 minutes, the sound pressure value dropped from 20-40 dB in the non-ventilated state to 10-20 dB.

[0104] Ultrasonic pressure test under oxygen flow conditions: Oxygen was introduced into the cleaning tank at a gas flow rate of 320 mL / min for 10 minutes, 20 minutes, and 30 minutes. The results also showed that the sound pressure value was significantly reduced. For example, under the conditions of 320 mL / min and 10 minutes, the sound pressure value dropped from 20-40 dB in the non-ventilated state to 7-20 dB.

[0105] 2. Cleanliness test Cleanliness refers to the degree of dust-free and contaminant-free state on the surface or inside of an object, and is usually used to evaluate the cleanliness level of the surface or environment. In the fields of semiconductor manufacturing, precision instruments, and pharmaceutical production, cleanliness is an important indicator for measuring product quality and reliability. Cleanliness is usually evaluated by detecting the number, size, and distribution of contaminants such as particulate matter, organic matter, and inorganic matter on the surface or in the environment. High cleanliness requirements mean that the number of contaminants on the surface or in the environment is extremely small, and the size and distribution of the contaminants are within an acceptable range to ensure that product performance and service life are not affected. The criteria for determining cleanliness are usually set according to industry specifications or production requirements, such as the maximum number of particles allowed per square centimeter or the particle concentration per cubic meter of air.

[0106] This application uses ImageJ software (version number: 1.53k) combined with scanning electron microscope (SEM) photos to determine the cleanliness of the device surface. First, save the SEM photo of the cleaned device surface in a common image format (such as JPG, PNG or TIF), then click "File"->"Open" in the menu bar in the ImageJ software, select the SEM photo file to be analyzed and import it. In order to improve the visibility of dust particles, click "Image"->"Adjust"->"Brightness / Contrast" in the menu bar to manually adjust the brightness and contrast of the image. If there is noise interference in the SEM photo, you can click "Process"->"Noise"->"Despeckle" in the menu bar to perform denoising to reduce the impact of background noise on dust particle counts.

[0107] Next, click "Image"->"Adjust"->"Threshold" in the menu bar to open the threshold adjustment tool. Separate the dust particles from the background by sliding the threshold bar so that the dust particles appear white (foreground) and the background appears black (background). After confirming the threshold setting, click the "Apply" button to convert the image into a binary image. Then, click "Analyze"->"Analyze Particles" in the menu bar to open the particle analysis tool. In the pop-up dialog box, set the minimum and maximum size range of the particles (for example, the minimum size is 0.5 μm² and the maximum size is 100 μm²) according to the magnification of the SEM photo and the actual size of the dust particles. According to the shape characteristics of the dust particles, set the roundness range (for example, 0.1 to 1.0) to exclude the interference of non-circular particles. Select "Outlines" to display the outlines of the identified dust particles on the image, click the "OK" button, ImageJ will automatically identify and count the dust particles, and display the counting results in the result window.

[0108] Check the automatic counting results. If you find any dust particles that are misidentified or missed, you can manually correct them. Use the "Edit" -> "Draw" tool to manually mark the unidentified dust particles; use the "Edit" -> "Clear" tool to delete the misidentified non-dust particles. After the correction is completed, click "Analyze" -> "Analyze Particles" again to update the counting results. Set the cleanliness index according to production requirements, for example, the maximum number of dust particles allowed per square centimeter is 10. Compare the ImageJ counting results with the set standards. If the counting results are lower than or equal to the standard value, the surface cleanliness of the device is determined to be qualified; if the counting results are higher than the standard value, the surface cleanliness of the device is determined to be unqualified and further cleaning or processing is required. Export the ImageJ counting results as a text file, click "File" -> "Save As" -> "Results" in the menu bar, select the save path and name the file. Record the judgment results in the test report, and save the processed SEM photos and binary images for subsequent analysis or review.

[0109] Among them, it is necessary to ensure that the resolution and clarity of the SEM photos are high enough to avoid missing or misidentifying dust particles. During binarization, the threshold setting should be adjusted according to the actual grayscale distribution of the SEM photos to ensure accurate separation of dust particles from the background. The size and roundness range of particle analysis should be reasonably set according to the actual characteristics of the dust particles to improve the accuracy of counting. Through the above detailed operation method, combined with ImageJ software (version number: 1.53k) and SEM photos, the cleanliness of the device surface can be determined efficiently and accurately, providing reliable technical support for quality control in the semiconductor manufacturing process.

[0110] Table 1 Cleaning results under different cleaning conditions Experimental conclusion: Experiments have found that in ultrasonic cleaning, when the medium is pure water, ultrasonic waves can be transmitted to the solid surface (such as the silicon surface after silicon wafer cutting) relatively efficiently, and the sound pressure value (sound pressure) measured at a certain distance is still high. When micro-nano bubbles are introduced into the aqueous solution, even if other conditions remain unchanged, the sound pressure value of the silicon surface measured at the same position decreases. This shows that the presence of bubbles causes the sound pressure transmitted to the solid surface to attenuate. In addition, in the aqueous solution system containing micro-nano bubbles, the attenuation of low-frequency ultrasound seems to be lower than that of high-frequency ultrasound, that is, low-frequency sound waves have relatively better penetration in the bubble-containing medium (or the effective sound pressure remains relatively high).

[0111] With the introduction of gas, whether it is air or oxygen, the sound pressure values ​​at all locations of the ultrasonic vibration plate are significantly reduced. This indicates that the introduction of bubbles causes the ultrasonic energy to be absorbed and scattered by the bubbles during the propagation process, reducing the propagation efficiency. At the same time, the introduction of bubbles changes the fluid flow field in the cleaning tank, further promoting the uniformity and efficiency of the cleaning effect.

[0112] The presence of micro-nano bubbles causes diffuse reflection and scattering of ultrasonic waves during propagation, reducing the propagation intensity and energy concentration of ultrasonic waves. This phenomenon was verified in the experiment by the reduction of sound pressure value.

[0113] Bubbles will experience acoustic resonance within a specific frequency range, triggering a strong nonlinear response, which will significantly dissipate acoustic energy in certain frequency bands. If the ultrasonic frequency is close to the characteristic resonance frequency of the bubble, the acoustic energy loss will be more obvious, which will reduce the sound pressure on the target surface.

[0114] Generally, high-frequency sound waves are more susceptible to attenuation caused by scattering and absorption in multiphase systems. Micro-nano bubbles scatter high-frequency sound waves more significantly, while for lower-frequency sound waves, the overall scattering and absorption effects of bubbles are relatively weakened. In addition, low-frequency sound waves have longer wavelengths and relatively better penetration, and are not easily dissipated in a short range.

[0115] The resonant frequency of micro-nano bubbles is closely related to their size. Generally, smaller bubbles correspond to higher resonant frequencies. When the ultrasonic frequency is much lower or higher than these bubble resonant frequencies, the effect of bubbles on sound wave attenuation will be different. For example, if the bubble resonant frequency is at the MHz level, and the ultrasonic frequency used is much lower than the resonant frequency, then the strong resonant absorption effect of the bubble is not obvious, and the attenuation will be weaker.

[0116] The greater the ultrasonic power (sound intensity), the more obvious the cavitation phenomenon. However, in the presence of micro-nano bubbles, the bubbles may disperse the sound energy first under non-resonant or low-amplitude conditions, thereby inhibiting the violent collapse of large-scale cavitation bubbles and the transmission of strong sound fields. If the power is too high, in areas with dense bubbles, it will cause excessive absorption or bubble aggregation, and even form larger bubbles and change the sound field distribution, which will produce nonlinear and complex effects.

[0117] The distance between the ultrasonic vibration plate and the silicon wafer surface will affect the distribution and attenuation of the sound field. The difference in the sound field characteristics between the near field and the far field will have different effects on bubble scattering and absorption.

[0118] The water flow state (static or with micro-flow) will affect the distribution and aggregation of bubbles, thereby changing the sound field and the efficiency of sound energy transmission. Moderate flow can prevent excessive aggregation of bubbles in a specific area, maintain a relatively uniform distribution of bubbles, and thus reduce local excessive scattering and absorption.

[0119] The introduction of bubbles changes the fluid flow field in the cleaning tank, forming a more complex flow state, which causes the dispersion and absorption of ultrasonic energy in the cleaning liquid, further reducing the local sound pressure value.

[0120] Micro-nano bubbles are prone to rupture and regeneration under the action of ultrasound, producing tiny cavitation bubble nuclei. These cavitation bubble nuclei not only absorb part of the ultrasonic energy, but also enhance the cleaning effect through synergistic effects, but also lead to an overall decrease in the sound pressure value.

[0121] The solid surface cleaning method and corresponding cleaning equipment provided by the present application, which combine micro-nano bubbles and ultrasonic technology, are intended to significantly improve the cleaning efficiency and effect by optimizing the generation, distribution and stability of bubbles, and accurately controlling the interaction between ultrasonic waves and bubbles. The invention is particularly suitable for efficient and uniform cleaning of precision surfaces such as electronic components, optical lenses, silicon wafer surfaces, quartz surfaces, food surfaces, cultural relics surfaces, precision mechanical parts, and medical device surfaces, overcoming the problems of uneven bubble generation, poor stability, and inaccurate ultrasonic control in the prior art. The above is only an implementation method of the present application, and does not limit the patent scope of the present application. Any equivalent structure or equivalent process transformation made by using the description and drawings of the present application, or directly or indirectly used in other related technical fields, is similarly included in the patent protection scope of the present application.

Claims

1. A cleaning method for improving the cleanliness of a solid surface, characterized in that: The cleaning method comprises: Injecting a cleaning medium containing a cleaning liquid and a gas mixture into the cleaning tank, wherein the gas exists in the cleaning medium in the form of micro-nano bubbles, the concentration of the micro-nano bubbles is 106-1012 / L, and the pressure of the gas is 0.01-2.00 MPa; Using a multi-frequency ultrasonic generator to apply ultrasonic waves with a frequency range of 1 kHz to 1 MHz into the cleaning tank; The cleaning medium is adjusted to circulate in the cleaning tank to clean the solid surface.

2. The cleaning method for improving the cleanliness of a solid surface according to claim 1, characterized in that: The multi-frequency ultrasonic generating device comprises an ultrasonic generator and an ultrasonic vibration plate, and the acoustic Reynolds number of the cleaning medium flowing through the ultrasonic vibration plate is 50-500; and / or The sound pressure on the surface of the ultrasonic vibration plate is 1-20 mV; and / or The surface of the ultrasonic vibration plate is flat, spherical or corrugated, and its roughness does not exceed 1 micron.

3. The cleaning method for improving the cleanliness of a solid surface according to claim 2, characterized in that: The flow velocity of the cleaning medium is 0.01-2.00 m / s; and / or The angle between the flow direction of the cleaning medium in the cleaning tank and the surface of the ultrasonic vibration plate is 0-90°; and / or The temperature in the cleaning tank is controlled within the range of 0-100°C.

4. The cleaning method for improving the cleanliness of a solid surface according to claim 2, characterized in that: The amplitude of the ultrasonic wave is in the range of 10-100 microns; and / or The ultrasonic generator is used to adjust the operating frequency and / or power in real time according to the bubble distribution and fluid characteristics of the cleaning medium; and / or The sound field formed in the cleaning tank is a dynamically adjusted uniform sound field.

5. The cleaning method for improving the cleanliness of a solid surface according to claim 1, characterized in that: The cleaning medium also includes a surface tension regulator, which is used to reduce the surface tension of the solution. The concentration of the surface tension regulator is 0.001-1.0 wt %; Optionally, the surface tension modifier comprises a surfactant.

6. The cleaning method for improving the cleanliness of a solid surface according to claim 1, characterized in that: The pressure of the gas is 1.0-1.5 Mpa; the temperature in the cleaning tank is 30-35°C; 0.05-0.08 wt% of a surfactant is added to the cleaning medium; the frequency of the ultrasonic wave is 40-80 kH; the flow rate of the cleaning medium is 0.01-1.00 m / s, and the gas is one or more of oxygen, ozone, and nitrogen.

7. The cleaning method for improving the cleanliness of a solid surface according to claim 1, characterized in that: The gas comprises one or more of oxygen, ozone, nitrogen, carbon dioxide or an inert gas; and / or The micro-nano bubbles come from a micro-nano bubble generating device, which generates the micro-nano bubbles by pressure dissolution, microporous aeration, membrane aeration, electrolysis, hydraulic cavitation, rotational flow, turbulent static mixing, ejector nozzle or hammer mill rotation.

8. The cleaning method for improving the cleanliness of a solid surface according to claim 1, characterized in that: The method is used for cleaning electronic components, optical lenses, silicon wafer surfaces, quartz surfaces, food surfaces, cultural relic surfaces, precision mechanical parts, and medical device surfaces.

9. A cleaning device for improving the cleanliness of a solid surface, characterized in that: The cleaning equipment comprises: A cleaning tank, used to accommodate a cleaning medium and a device to be cleaned, the cleaning tank comprising a medium inlet and a medium outlet, the medium inlet being used to access a cleaning medium, the cleaning medium comprising a mixture of a cleaning liquid and a gas, the gas being present in the cleaning medium in the form of micro-nano bubbles, the concentration of the micro-nano bubbles being 106-1012 / L, and the pressure of the gas being 0.01-2.00 MPa; A multi-frequency ultrasonic generator, arranged on the inner wall of the cleaning tank, for applying ultrasonic waves with a frequency of 1 kHz to 1 MHz into the cleaning tank; The reflux device comprises a reflux pipe, wherein the reflux pipe is respectively connected to the medium inlet and the medium outlet, and the reflux device is used to adjust the circulation of the cleaning medium in the cleaning tank to clean the solid surface.

10. The cleaning device for improving the cleanliness of a solid surface according to claim 9, characterized in that: The multi-frequency ultrasonic generating device comprises an ultrasonic generator and an ultrasonic vibration plate. The surface morphology of the ultrasonic vibration plate is plane, spherical or corrugated, and its surface roughness does not exceed 1 micron. The amplitude range of the ultrasonic wave is 10-100 microns.

11. The cleaning device for improving the cleanliness of a solid surface according to claim 9, characterized in that: The reflux device further comprises a fluid pump, wherein the fluid pump is a fluid pump with adjustable flow rate, and the fluid pump is used to control the flow velocity of the cleaning medium within the range of 0.01 to 2 m / s.

12. The cleaning device for improving the cleanliness of a solid surface according to claim 9, characterized in that: The cleaning device also includes: A micro-nano bubble generating device, wherein the micro-nano bubble generating device generates the micro-nano bubbles by pressure dissolution, microporous aeration, membrane aeration, electrolysis, hydrodynamic cavitation, rotary flow, turbulent static mixing, ejector nozzle or hammer mill rotation; and / or A temperature control system, comprising a temperature sensor and a heating / cooling unit, for controlling the temperature of the cleaning medium within a range of 0 to 100°C.

13. The cleaning device for improving the cleanliness of a solid surface according to claim 9, characterized in that: The cleaning device also includes: A control unit is electrically connected to the micro-nano bubble generating device, the ultrasonic generator, the reflux device and the temperature control system, and is used to monitor the micro-nano bubble concentration, the acoustic field distribution and the temperature parameters, and automatically adjust the equipment operation parameters based on the monitoring data.

14. The cleaning device for improving the cleanliness of a solid surface according to claim 9, characterized in that: The cleaning device also includes: A deionized water system, wherein the deionized water system is used for secondary washing of the solid surface after ultrasonic cleaning, and the flow rate of the deionized water is 0.5-2.0 m / s; and / or A membrane separation device, wherein the membrane separation device is used to recycle and reuse the effective ingredients in the liquid in the cleaning tank, wherein the effective ingredients include one or more of acids, alkalis, functional agents, and micro-nano bubbles; and / or a drying device, wherein the drying device is used to dry the cleaned solid material, the temperature is controlled at 60-80°C, the vacuum degree is controlled at -0.08 to -0.1 MPa, and the drying time is 6 to 12 hours.

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