Ultrasonic dust removal device and screen printing equipment

Abstract

The application discloses an ultrasonic dust removal device and a screen printing equipment, which are used for removing the impurities on the surface of a silicon wafer on a conveying belt of the screen printing equipment. The ultrasonic dust removal device comprises an ultrasonic air knife, the ultrasonic air knife comprises a first end and a second end, the first end is provided with an air outlet, the air outlet is arranged towards the conveying belt, the ultrasonic air knife is arranged obliquely, along the conveying direction of the conveying belt, the ultrasonic air knife gradually moves away from the conveying belt from the first end to the second end, and a dust collector is arranged upstream of the ultrasonic air knife along the conveying direction of the conveying belt, and the dust collector is used for adsorbing the impurities stripped by the ultrasonic air knife. The high-frequency vibration and cavitation effect of the ultrasonic air knife can improve the removal capacity of the micro-particles, avoids scratching the surface of the silicon wafer, the dust collector prevents the impurities from spreading in the working environment, the effective removal of the impurities on the surface of the silicon wafer reduces the abrasion of the printing screen caused by the impurities, reduces the probability of occurrence of the bad phenomenon, thereby prolongs the service life of the printing screen and improves the production efficiency.

Description

Technical Field

[0001] This application relates to the field of photovoltaic technology, and in particular to an ultrasonic dust removal device and a screen printing equipment. Background Technology

[0002] In the photovoltaic manufacturing industry, screen printing equipment is a typical piece of automated equipment. Before and after the PECVD (Plasma-Enhanced Chemical Vapor Deposition) process in solar silicon wafer production, it plays a crucial role in the automatic loading of silicon wafers between the graphite boat and the wafer basket. During this process, the cleanliness of the silicon wafer surface plays a decisive role in production quality, but traditional silicon wafer dust removal technologies have significant shortcomings.

[0003] Currently used air-blowing dust removal methods are ineffective at cleaning hard-to-reach areas on silicon wafer surfaces, especially for tiny particles, where the removal rate is extremely low, and they are unable to remove stubborn particles already attached to the silicon wafer surface. While brush cleaning can remove surface impurities to some extent, it easily scratches the silicon wafer during contact, leading to defects and affecting product quality. Wet cleaning methods, on the other hand, can contaminate the silicon wafers and are difficult to adapt to the requirements of photovoltaic cell manufacturing processes, severely limiting their practical application and hindering the high-quality development of the photovoltaic manufacturing industry. Utility Model Content

[0004] This application discloses an ultrasonic dust removal device and a screen printing equipment, which can reduce the wear of impurities on the printing screen, reduce the probability of defects such as screen bursting, missing prints, and broken screens, thereby extending the service life of the printing screen, reducing equipment maintenance costs, and improving production efficiency.

[0005] To achieve the above objectives, this application discloses an ultrasonic dust removal device for removing impurities from the surface of silicon wafers on the conveyor belt of a screen printing equipment, comprising:

[0006] An ultrasonic air knife, comprising a first end and a second end, wherein the first end is provided with an air outlet facing the conveyor belt, the ultrasonic air knife is inclined and gradually moves away from the conveyor belt from the first end to the second end along the conveying direction of the conveyor belt.

[0007] A vacuum cleaner is located upstream of the ultrasonic air knife along the conveyor belt's conveying direction. The vacuum cleaner is used to remove impurities stripped off by the ultrasonic air knife.

[0008] In one possible implementation, the ultrasonic air knife is positioned above the conveyor belt along a conveying direction perpendicular to the conveyor belt, with the first end of the ultrasonic air knife positioned at a distance of 8mm-12mm from the conveyor belt.

[0009] In one possible implementation, the vacuum cleaner includes a first vacuum cleaner and a second vacuum cleaner, the first vacuum cleaner being positioned above the conveyor belt and the second vacuum cleaner being positioned below the conveyor belt and opposite to the first vacuum cleaner.

[0010] In one possible implementation, the ultrasonic dust removal device further includes an electrically connected sensor and a controller, the ultrasonic air knife being electrically connected to the controller. Along the conveying direction of the conveyor belt, the sensor is located upstream of the ultrasonic air knife, the sensor is used to sense the position of the silicon wafer, and the controller is used to control the start and stop of the ultrasonic air knife based on the silicon wafer position detected by the sensor.

[0011] In one possible implementation, an ion generator is provided at the air outlet, the ion generator being used to remove static charge from the surface of the silicon wafer.

[0012] In one possible implementation, the ultrasonic air knife includes a housing with a gas channel communicating with the air outlet. The housing is provided with multiple gas connectors, each of which is connected to the air outlet through the gas channel. The multiple gas connectors are used to adjust the gas flow rate at the air outlet.

[0013] In one possible implementation, the ultrasonic air knife is a multi-band ultrasonic air knife.

[0014] This application also discloses a screen printing apparatus, including a printing machine, a conveyor belt, and an ultrasonic dust removal device, wherein the conveyor belt is used to transport silicon wafers to the printing machine, and the ultrasonic dust removal device is as described in any of the preceding claims.

[0015] In one possible implementation, the ultrasonic air knife is inclined at a 45-degree angle to the conveyor belt.

[0016] In one possible implementation, the conveyor belt includes a vacuum belt for adsorbing and conveying the silicon wafer, and the ultrasonic air knife is positioned above the vacuum belt.

[0017] Compared with the prior art, the beneficial effects of this application are as follows:

[0018] In the ultrasonic dust removal device and screen printing equipment provided in this application, the ultrasonic air knife moves away from the conveyor belt from the first end to the second end along the conveyor belt's conveying direction. This inclined layout allows the ultrasonic airflow ejected from the outlet to form a specific angle with the silicon wafer surface. On the one hand, this ensures that the airflow can fully cover the silicon wafer surface, avoiding cleaning dead zones; on the other hand, after the airflow acts on the silicon wafer surface, it has a component force along the conveying direction, causing the peeled impurities to move along the silicon wafer surface, facilitating subsequent collection by the vacuum cleaner. The high-frequency vibration characteristics of ultrasound enable the airflow to generate a strong impact force and cavitation effect, effectively breaking the adhesion between impurities and the silicon wafer surface, peeling off impurities such as tiny particles and stubborn deposits from the silicon wafer surface. Along the conveyor belt's conveying direction, the vacuum cleaner is located upstream of the ultrasonic air knife. After the ultrasonic air knife peels off impurities from the silicon wafer surface, the impurities will first be blown towards the vacuum cleaner, allowing the vacuum cleaner to capture the peeled impurities in a timely manner, preventing the impurities from re-adhering to the silicon wafer surface or scattering in the working environment.

[0019] Thus, the high-frequency vibration and cavitation effect of the ultrasonic air knife significantly improve the removal capability of fine particles. Compared with traditional air-blowing dust removal methods, the removal rate of various impurities is greatly improved, effectively solving the problems of dead corners and low removal rate of fine particles in traditional dust removal. This device uses non-contact ultrasonic airflow dust removal, avoiding scratches on the silicon wafer surface caused by contact methods such as brush cleaning, effectively reducing the defect rate of silicon wafers due to scratches, and ensuring the surface quality and electrical performance of the silicon wafers. The vacuum cleaner promptly adsorbs the removed impurities, preventing them from spreading in the working environment. This avoids impurities re-adhering to the silicon wafer surface and affecting the cleaning effect, and also reduces dust pollution in the production environment, which helps maintain a clean production environment and meets the high requirements of the photovoltaic manufacturing industry. The effective removal of impurities from the silicon wafer surface reduces wear on the printing screen, lowering the probability of defects such as screen bursting, missing prints, and broken grids, thereby extending the service life of the printing screen, reducing equipment maintenance costs, and improving production efficiency. Attached Figure Description

[0020] To more clearly illustrate the technical solutions in the embodiments of this application, the drawings used in the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of this application. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0021] Figure 1 A schematic diagram of the working state of an ultrasonic dust removal device and a conveyor belt provided in an embodiment of this utility model;

[0022] Figure 2 A schematic diagram of the structure of an ultrasonic dust removal device and a conveyor belt in cooperation with an embodiment of this utility model;

[0023] Figure 3 for Figure 2 A magnified view of a section at point A in the middle;

[0024] Figure 4 for Figure 3 A magnified view of a section at point B in the middle.

[0025] Explanation of reference numerals in the attached figures:

[0026] 10-Ultrasonic air knife; 11-First end; 111-Air outlet; 1111-Ion generator; 12-Second end; 13-Housing; 131-Gas connector;

[0027] 20 - Vacuum cleaner; 21 - First vacuum cleaner; 22 - Second vacuum cleaner;

[0028] 30-Sensor;

[0029] 40 - Conveyor belt; 41 - Vacuum belt. Detailed Implementation

[0030] The technical solutions of the embodiments of this application will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of this application, and not all embodiments. Based on the embodiments of this application, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of this application.

[0031] In this application, the terms "installation," "setup," "equipped with," "connection," and "linked" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral structure; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium, or an internal connection between two devices, components, or parts. Those skilled in the art can understand the specific meaning of the above terms in this application based on the specific circumstances.

[0032] Furthermore, the terms "first," "second," etc., are primarily used to distinguish different devices, elements, or components (which may be the same or different in specific type and construction), and are not intended to indicate or imply the relative importance or quantity of the indicated devices, elements, or components. Unless otherwise stated, "a plurality of" means two or more.

[0033] In the photovoltaic manufacturing industry, screen printing equipment is a typical piece of automated equipment. Before and after the PECVD (Plasma-Enhanced Chemical Vapor Deposition) process in solar silicon wafer production, it plays a crucial role in the automatic loading of silicon wafers between the graphite boat and the wafer basket. During this process, the cleanliness of the silicon wafer surface plays a decisive role in production quality, but traditional silicon wafer dust removal technologies have significant shortcomings.

[0034] Currently used air-blowing dust removal methods are ineffective at cleaning hard-to-reach areas on silicon wafer surfaces, especially for tiny particles, where the removal rate is extremely low, and they are unable to remove stubborn particles already attached to the silicon wafer surface. While brush cleaning can remove surface impurities to some extent, it easily scratches the silicon wafer during contact, leading to defects and affecting product quality. Wet cleaning methods, on the other hand, can contaminate the silicon wafers and are difficult to adapt to the requirements of photovoltaic cell manufacturing processes, severely limiting their practical application and hindering the high-quality development of the photovoltaic manufacturing industry.

[0035] In view of this, some embodiments of this application provide an ultrasonic dust removal device and a screen printing equipment. By combining an ultrasonic air knife and a vacuum cleaner, the wear of impurities on the printing screen can be reduced, the probability of defects such as screen bursting, missing prints, and broken screens can be reduced, thereby extending the service life of the printing screen, reducing equipment maintenance costs, and improving production efficiency.

[0036] The present application will be described in detail below through specific embodiments:

[0037] The ultrasonic dust removal device in the embodiments of this application, such as Figures 1 to 4 As shown, an ultrasonic dust removal device is used to remove impurities from the surface of silicon wafers on the conveyor belt 40 of a screen printing equipment, comprising:

[0038] The ultrasonic air knife 10 includes a first end 11 and a second end 12. The first end 11 is provided with an air outlet 111, which is positioned facing the conveyor belt 40. The ultrasonic air knife 10 is inclined and gradually moves away from the conveyor belt 40 from the first end 11 to the second end 12 along the conveying direction of the conveyor belt 40.

[0039] The vacuum cleaner 20 is located upstream of the ultrasonic air knife 10 along the conveying direction of the conveyor belt 40. The vacuum cleaner 20 is used to adsorb the impurities stripped off by the ultrasonic air knife 10.

[0040] In the ultrasonic dust removal device provided in this embodiment, the ultrasonic air knife 10 moves away from the conveyor belt 40 from the first end 11 to the second end 12 along the conveying direction of the conveyor belt 40. This inclined arrangement allows the ultrasonic airflow ejected from the outlet 111 to form a specific angle with the silicon wafer surface. On the one hand, this ensures that the airflow can fully cover the silicon wafer surface, avoiding cleaning dead zones; on the other hand, after the airflow acts on the silicon wafer surface, it has a component force along the conveying direction, causing the peeled impurities to move along the silicon wafer surface, making it easier for the subsequent vacuum cleaner 20 to collect them. The high-frequency vibration characteristics of ultrasound enable the airflow to generate a strong impact force and cavitation effect, effectively destroying the adhesion between impurities and the silicon wafer surface, peeling off impurities such as tiny particles and stubborn deposits from the silicon wafer surface. Along the conveying direction of the conveyor belt 40, the vacuum cleaner 20 is located upstream of the ultrasonic air knife 10. After the ultrasonic air knife 10 peels off the impurities from the silicon wafer surface, the impurities will first be blown towards the vacuum cleaner 20, allowing the vacuum cleaner 20 to capture the peeled impurities in time, preventing the impurities from re-attaching to the silicon wafer surface or drifting in the working environment.

[0041] Thus, the high-frequency vibration and cavitation effect of the ultrasonic air knife 10 significantly improves the removal ability of fine particles. Compared with traditional air blowing dust removal methods, the removal rate of various impurities is greatly improved, effectively solving the problems of dead corners and low removal rate of fine particles in traditional dust removal. This device adopts non-contact ultrasonic airflow dust removal, avoiding scratches on the silicon wafer surface caused by contact methods such as brush cleaning, effectively reducing the defect rate of silicon wafer scratches, and ensuring the surface quality and electrical performance of silicon wafers. The vacuum cleaner 20 promptly adsorbs the stripped impurities, preventing them from spreading in the working environment. This not only prevents impurities from re-adhering to the silicon wafer surface and affecting the cleaning effect, but also reduces dust pollution in the production environment, which is conducive to maintaining a clean production environment and meets the high requirements of the photovoltaic manufacturing industry for the production environment. The effective removal of impurities on the silicon wafer surface reduces the wear of impurities on the printing screen, reduces the probability of defects such as screen bursting, missing printing, and broken grids, thereby extending the service life of the printing screen, reducing equipment maintenance costs, and improving production efficiency.

[0042] In the diagram, the X direction is the conveying direction of conveyor belt 40, and the Y direction is the vertical direction (i.e., perpendicular to the conveying direction of conveyor belt 40).

[0043] It needs to be explained that, Figure 1 A structural diagram illustrating the working state of the ultrasonic dust removal device and the conveyor belt. Figure 1 The dashed arrows in the image indicate the direction of gas flow. Figure 1 The solid arrows in the image indicate the direction of silicon wafer transport on the conveyor belt.

[0044] In one possible implementation, such as Figures 2 to 4As shown, the ultrasonic air knife 10 is used to be positioned above the conveyor belt 40, along a conveying direction perpendicular to the conveyor belt 40. The distance H between the first end 11 of the ultrasonic air knife 10 and the conveyor belt 40 is 8mm-12mm.

[0045] Within a distance range of 8mm-12mm, the impact pressure generated by the ultrasonic air knife 10 can both break the van der Waals adsorption between particles and the silicon wafer surface through cavitation effect, and will not cause mechanical damage to the silicon wafer. The energy density uniformity error is ≤5%, ensuring the consistent cleaning effect of the silicon wafer surface at different locations, and is especially suitable for uniform cleaning of large-size silicon wafers.

[0046] When the distance is less than 8mm, excessive airflow impact pressure can cause airflow disturbances (such as localized eddies) on the silicon wafer surface, potentially leading to displacement or vibration of the thin silicon wafer. When the distance exceeds 12mm, the ultrasonic energy attenuates significantly with distance, resulting in insufficient airflow impact strength and difficulty in effectively removing attached particles. Controlling the distance within a safe range prevents excessive airflow from causing the silicon wafer to "jump" or shift, ensuring that the silicon wafer maintains a stable relative position with the conveyor belt 40 during the cleaning process, facilitating precise gripping by the subsequent robotic arm.

[0047] Specifically, the distance H between the first end 11 of the ultrasonic air knife 10 and the conveyor belt 40 can be 8mm, 10mm or 12mm, as long as it is within the range of 8mm-12mm.

[0048] In some embodiments, such as Figure 2 As shown, the vacuum cleaner 20 includes a first vacuum cleaner 21 and a second vacuum cleaner 22. The first vacuum cleaner 21 is positioned above the conveyor belt 40, and the second vacuum cleaner 22 is positioned below the conveyor belt 40 and is positioned opposite to the first vacuum cleaner 21.

[0049] The first vacuum cleaner 21 (upper suction port) is located above the conveyor belt 40, on the same side as the ultrasonic air knife 10, and the second vacuum cleaner 22 (lower suction port) is installed below the conveyor belt 40. The two are connected by a through-type suction pipe to form a bidirectional airflow channel perpendicular to the silicon wafer surface.

[0050] The first vacuum cleaner 21 targets impurity particles (such as silicon nitride debris left over from the PECVD process and dust adsorbed during transportation) on the surface of the silicon wafer, which are swept away by the ultrasonic air knife 10. The second vacuum cleaner 22 targets residual fallen particles. The combination of the two achieves multiple cleaning processes and reduces the particle residue rate. The vertical negative pressure field formed by the upper and lower vacuum cleaners 20 can quickly capture the stripped particles and prevent them from circulating and suspending inside the equipment.

[0051] In some embodiments, such as Figure 3As shown, the ultrasonic dust removal device also includes an electrically connected sensor 30 and a controller. The ultrasonic air knife 10 is electrically connected to the controller. Along the conveying direction of the conveyor belt 40, the sensor 30 is located upstream of the ultrasonic air knife 10. The sensor 30 is used to sense the position of the silicon wafer, and the controller is used to control the start and stop of the ultrasonic air knife 10 according to the silicon wafer position detected by the sensor 30.

[0052] Thus, during non-wafer transit periods, when sensor 30 does not detect a wafer, the ultrasonic air knife 10 remains in standby mode to prevent it from idling, saving electricity and resources. The vacuum cleaner 20 also remains in standby mode, further reducing energy consumption. When sensor 30 detects the arrival of a wafer, the controller activates the ultrasonic air knife 10 and vacuum cleaner 20 via a signal from sensor 30, ensuring the air knife opens upon wafer arrival. In emergencies (such as conveyor belt 40 jamming), the controller receives an emergency stop signal and cuts off the air knife power to prevent continuous airflow from causing pushing damage to the stacked wafers.

[0053] Through a closed-loop logic of "induction triggering - precise control - emergency braking", the dust removal process is made intelligent, energy-saving and safe. It can not only reduce energy consumption and maintenance costs, but also lay the foundation for optimizing the yield of subsequent printing processes by improving process precision.

[0054] The sensor 30 can be a laser pair sensor 30, an infrared diffuse reflection sensor 30, etc., and this application does not limit it.

[0055] In some embodiments, such as Figure 3 and Figure 4 As shown, an ion generator 1111 is installed at the air outlet 111. The ion generator 1111 is used to remove static charge from the surface of the silicon wafer.

[0056] During transport, the static electricity generated by friction on the silicon wafer will attract particulate contaminants ≥0.1μm from the air. The removed impurities may re-attach to the downstream area of ​​the silicon wafer due to static electricity. The positive and negative ions released by the ion generator 1111 neutralize the charge on the surface of the silicon wafer, causing the particulate contaminants to lose their electrostatic attraction. Combined with ultrasonic airflow, they are easier to remove, further cleaning the residual particles. After ion neutralization, the impurity particles are electrically neutral in the airflow, improving the capture efficiency of the vacuum cleaner 20 and improving the cleaning yield.

[0057] Static electricity on silicon wafer surfaces easily attracts dust, metal particles, and other contaminants from the air, affecting chip performance. The ion generator 1111 neutralizes this static charge by releasing positive and negative ions, reducing surface potential and particle adsorption, thereby lowering defect rates and improving yield. Static electricity buildup can trigger instantaneous discharges, breaking down the oxide layer on the silicon wafer surface or transistor structures (such as the gate oxide layer), causing permanent damage. Ion neutralization keeps the surface static voltage within a safe range, protecting precision devices.

[0058] In some embodiments, such as Figure 3 and Figure 4 As shown, the ultrasonic air knife 10 includes a housing 13, which has a gas channel that is connected to an air outlet 111. The housing 13 is provided with multiple gas connectors 131, which are all connected to the air outlet 111 through the gas channel. The multiple gas connectors 131 are used to adjust the gas flow rate of the air outlet 111.

[0059] Therefore, the cleaning mode can be quickly switched by adjusting the number and opening degree of gas connectors 131 to target different specifications of silicon wafers or surface contamination levels. For example, thin silicon wafers can be supplied with gas using a single connector or multiple connectors with a smaller volume of gas to avoid airflow impact causing fragmentation; in high-contamination scenarios (such as residual slurry after silicon wafer cutting), multiple connectors can be used to supply gas simultaneously, improving cleaning time and production capacity at the same time.

[0060] The multi-connector diversion design reduces the lateral uniformity error of the airflow at the outlet, avoiding differences in cleaning effectiveness between the silicon wafer edge and center areas. Simultaneously, by closing or reducing the air intake at some connectors, energy consumption and compressed air costs can be reduced under non-full-load conditions, saving expenses.

[0061] In some embodiments, the ultrasonic air knife 10 is a multi-band ultrasonic air knife 10.

[0062] Low-frequency (e.g., 30kHz) cleaning efficiency is greater than 99% for particles larger than 5-10μm; high-frequency (e.g., 100kHz) cleaning efficiency is improved to 95% for particles between 0.1-1μm, meeting the requirements for ultra-clean surfaces of silicon wafers. In cases where micron-sized slurry particles and nano-sized cutting fluid residues may coexist on the silicon wafer surface, low-frequency sound waves are used to first break the mechanical adhesion between the slurry particles and the silicon wafer, while high-frequency sound waves, combined with the cavitation effect of airflow, decompose the organic matter in the cutting fluid, avoiding the need for repeated cleaning at a single frequency in traditional methods.

[0063] This application also discloses a screen printing device, including a printing machine, a conveyor belt 40, and an ultrasonic dust removal device. The conveyor belt 40 is used to transport silicon wafers to the printing machine. The ultrasonic dust removal device in this screen printing device is the ultrasonic dust removal device described above. Therefore, the screen printing device in this embodiment has roughly the same technical effect as the ultrasonic dust removal device described above. Since the technical effect of the ultrasonic dust removal device has been fully explained, it will not be repeated here.

[0064] In some embodiments, such as Figures 2 to 4 As shown, the tilt angle α between the ultrasonic air knife 10 and the conveyor belt 40 is 45 degrees.

[0065] The ultrasonic air knife 10 is inclined at 45 degrees to the conveyor belt 40 in the conveying direction, with the air outlet 111 facing the conveyor belt 40, forming an airflow vector that has both impact and pushing effects. The 45-degree angle allows the ultrasonic airflow to generate horizontal shearing force and vertical impact force at the same time, and also makes the tangential and normal components of the airflow on the silicon wafer surface reach a balanced state. Along the conveying direction, the vertical distance between the first end 11 (air outlet 111) of the ultrasonic air knife 10 and the silicon wafer surface is usually controlled at 8mm-12mm to ensure that the airflow maintains good impact pressure when it reaches the silicon wafer.

[0066] Furthermore, the 45-degree inclination direction causes the stripped particles to move rapidly towards the vacuum cleaner 20 in the opposite direction of the tangential airflow, shortening the residence time of the particles on the silicon wafer surface and avoiding secondary contamination. The inclined airflow induces a rotating vortex on the workpiece surface, prolonging the contact time between the airflow and the workpiece, while the centrifugal force of the vortex further separates the tiny particles.

[0067] In some embodiments, such as Figure 2 and Figure 3 As shown, the conveyor belt 40 includes a vacuum belt 41, which is used to adsorb and transport silicon wafers, and an ultrasonic air knife 10 is disposed above the vacuum belt 41.

[0068] Because the ultrasonic air knife 10 is close to the conveyor belt 40 and the ultrasonic air force is strong, the silicon wafer is transported on the vacuum belt 41. The negative pressure adsorption of the vacuum belt 41 keeps the silicon wafer in a fixed position during the transport process. Even when there is high-speed air force or sudden stop and start of the transport, the silicon wafer will not shift. The stable transport posture provides a reliable guarantee for the subsequent printing process and reduces the problem of damage caused by silicon wafer position deviation.

[0069] The negative pressure of the vacuum belt 41 can be flexibly adjusted according to the thickness and material of the silicon wafers, adapting to the production needs of various silicon wafer specifications. Furthermore, the integrated design of the ultrasonic dust removal device and the vacuum belt 41 eliminates the need for large-scale modifications to existing screen printing equipment, allowing for rapid application to different models of printing machines, demonstrating excellent versatility and economy.

[0070] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of this utility model, and are not intended to limit it. Although the utility model has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some or all of the technical features therein. Such modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the scope of the technical solutions of the embodiments of this utility model.

Claims

1. An ultrasonic dust removal device for removing impurities from the surface of silicon wafers on the conveyor belt of a screen printing equipment, characterized in that, include: An ultrasonic air knife, comprising a first end and a second end, wherein the first end is provided with an air outlet facing the conveyor belt, the ultrasonic air knife is inclined and gradually moves away from the conveyor belt from the first end to the second end along the conveying direction of the conveyor belt. A vacuum cleaner is located upstream of the ultrasonic air knife along the conveyor belt's conveying direction. The vacuum cleaner is used to remove impurities stripped off by the ultrasonic air knife.

2. The ultrasonic dust removal device according to claim 1, characterized in that, The ultrasonic air knife is used to be positioned above the conveyor belt, along a conveying direction perpendicular to the conveyor belt, with the first end of the ultrasonic air knife positioned at a distance of 8mm-12mm from the conveyor belt.

3. The ultrasonic dust removal device according to claim 1 or 2, characterized in that, The vacuum cleaner includes a first vacuum cleaner and a second vacuum cleaner. The first vacuum cleaner is positioned above the conveyor belt, and the second vacuum cleaner is positioned below the conveyor belt and opposite to the first vacuum cleaner.

4. The ultrasonic dust removal device according to claim 1 or 2, characterized in that, The ultrasonic dust removal device also includes an electrically connected sensor and a controller. The ultrasonic air knife is electrically connected to the controller. Along the conveying direction of the conveyor belt, the sensor is located upstream of the ultrasonic air knife. The sensor is used to sense the position of the silicon wafer. The controller is used to control the start and stop of the ultrasonic air knife according to the silicon wafer position detected by the sensor.

5. The ultrasonic dust removal device according to claim 1 or 2, characterized in that, An ion generator is installed at the air outlet, and the ion generator is used to remove static charge from the surface of the silicon wafer.

6. The ultrasonic dust removal device according to claim 1 or 2, characterized in that, The ultrasonic air knife includes a housing with a gas channel inside, the gas channel being connected to the air outlet. The housing is provided with multiple gas connectors, each of which is connected to the air outlet through the gas channel. The multiple gas connectors are used to adjust the gas flow rate at the air outlet.

7. The ultrasonic dust removal device according to claim 1 or 2, characterized in that, The ultrasonic air knife is a multi-band ultrasonic air knife.

8. A screen printing device, characterized in that, The device includes a printing press, a conveyor belt, and an ultrasonic dust removal device, wherein the conveyor belt is used to transport silicon wafers to the printing press, and the ultrasonic dust removal device is as described in any one of claims 1 to 7.

9. The screen printing equipment according to claim 8, characterized in that, The ultrasonic air knife is inclined at a 45-degree angle to the conveyor belt.

10. The screen printing equipment according to claim 9, characterized in that, The conveyor belt includes a vacuum belt for adsorbing and conveying the silicon wafer, and the ultrasonic air knife is located above the vacuum belt.

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