Normal-pressure plasma discharge device

Abstract

The utility model provides a normal-pressure plasma discharge device. The normal-pressure plasma discharge device comprises a device body, an air inlet, an outlet and a dielectric electrode, a columnar containing cavity is formed in the device body, a dielectric electrode is installed in the columnar containing cavity, and a plurality of cooling holes are formed in the dielectric electrode. The gas inlet is formed in one side, close to the process gas input source, of the device body, and the gas inlet is communicated with the columnar accommodating cavity; an outlet is formed in the side, close to the to-be-treated workpiece, of the device body, is formed in the axial direction of the columnar containing cavity in a slit shape and communicates with the columnar containing cavity. According to the device, the plurality of cooling holes are formed in the dielectric electrode, heat generated in the discharging process can be taken away in time, and performance reduction or damage caused by overheating of the electrode is avoided. The outlet is formed in the axial direction of the columnar containing cavity in a slit shape, wide plasma beams can be generated, a larger area can be covered in the working process of the device, and compared with a narrow-beam plasma processing mode, the processing efficiency is remarkably improved.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of atmospheric pressure plasma discharge device, in particular to an atmospheric pressure plasma discharge device. BACKGROUND

[0002] With the rapid development of science and technology, the requirements for the surface properties of materials in various industries are continuously increasing. In the electronics industry, ultra-fine processing of the surface of silicon wafers is required to remove tiny impurities and organic matter to ensure stable chip performance. In the automotive manufacturing field, the surface treatment of automotive parts directly affects the adhesion of the coating, which in turn affects the appearance quality and service life of the automobile. In the medical and health industry, the surface treatment of medical devices is related to their biocompatibility, which plays a key role in preventing infection and ensuring patient safety. Plasma cleaning technology has become an important means to meet these needs because it can effectively improve the microstructure and chemical properties of the material surface.

[0003] Currently, plasma cleaning equipment mainly includes vacuum plasma cleaning machines and atmospheric pressure plasma cleaning machines. Vacuum plasma cleaning machines generate plasma by ionizing process gas after the processing cavity is pumped to a vacuum state. However, it also has significant drawbacks. On the one hand, the process of pumping and breaking the vacuum consumes a lot of time, prolonging the production cycle. On the other hand, the number of products processed at a time is limited, which greatly limits the production capacity and results in high production costs, so it is only suitable for production scenarios that have special requirements for vacuum environments or small batches and high precision.

[0004] In summary, the existing plasma cleaning technology has many shortcomings in practical application and cannot simultaneously meet the requirements of high efficiency, high precision, and low cost. Developing a new type of atmospheric pressure plasma processing device that can generate long and strong plasma beams under atmospheric pressure to improve the uniformity, precision, and efficiency of surface treatment has become a key problem that needs to be solved in this field. CONTENT OF THE INVENTION

[0005] In view of the above problems, the present application is proposed to provide an atmospheric pressure plasma discharge device that overcomes the above problems or at least partially solves the above problems. The atmospheric pressure plasma discharge device comprises a device body, a gas inlet, an outlet, and a dielectric electrode. A cylindrical accommodating cavity is provided in the device body, and the dielectric electrode is installed in the cylindrical accommodating cavity. The dielectric electrode is provided with a plurality of cooling holes. The device body is provided with the gas inlet on the side close to the process gas input source, and the gas inlet is in communication with the cylindrical accommodating cavity. The device body is provided with the outlet on the side close to the workpiece to be processed, and the outlet is in the form of a slit and is provided along the axial direction of the cylindrical accommodating cavity and in communication with the cylindrical accommodating cavity.

[0006] Optionally, the plurality of cooling holes are arranged in a circular array, and the spacing between adjacent cooling holes is equal.

[0007] Optionally, the dielectric electrode comprises a metal tube and a dielectric film wrapped around the outer surface of the metal tube.

[0008] Optionally, the dielectric film is made of one of ceramic, glass or quartz.

[0009] Optionally, the air inlet is connected to the cylindrical accommodating cavity through a gas mixing channel.

[0010] One end of the gas mixing channel is connected to the air inlet, and the other end extends into the cylindrical accommodating cavity.

[0011] Optionally, the gas mixing channel is provided with a turbulence structure.

[0012] Optionally, the turbulence structure is a spiral protrusion arranged on the inner wall of the gas mixing channel or a staggered baffle.

[0013] Optionally, the device further comprises a grounding metal piece.

[0014] The grounding metal piece is arranged around the outer periphery of the device body, and an insulating layer is arranged between the grounding metal piece and the device body.

[0015] Optionally, the device body is made of aluminum alloy or stainless steel, and the inner wall of the device body is polished.

[0016] Optionally, the air inlet is provided with a valve.

[0017] The present application has the following advantages:

[0018] In the embodiments of the present application, in order to solve the problems that the plasma cleaning technology in the prior art has many deficiencies in practical application and it is difficult to simultaneously consider the requirements of high efficiency, high precision and low cost, the present application provides a normal pressure plasma discharge device, which specifically comprises a device body, a gas inlet, an outlet and a dielectric electrode; a columnar accommodating cavity is arranged in the device body, the dielectric electrode is arranged in the columnar accommodating cavity, and the dielectric electrode is provided with a plurality of cooling holes; the device body is provided with the gas inlet on the side close to the process gas input source, the gas inlet is communicated with the columnar accommodating cavity; the device body is provided with the outlet on the side close to the workpiece to be processed, the outlet is provided in a slit shape along the axial direction of the columnar accommodating cavity and is communicated with the columnar accommodating cavity. The above device is provided with a plurality of cooling holes in the dielectric electrode, which can timely take away the heat generated in the discharge process, so as to avoid the performance degradation or damage of the electrode due to overheating. This not only can maintain the stable work of the electrode and prolong the service life of the electrode, but also can ensure the stability and continuity of the generated plasma, thereby providing a stable plasma source for subsequent processing. The outlet is provided in a slit shape along the axial direction of the columnar accommodating cavity, which can generate a wide plasma beam, can cover a larger area during the working process of the device, and compared with the narrow beam plasma processing mode, the processing efficiency is significantly improved, which can meet the needs of large-scale batch production. BRIEF DESCRIPTION OF DRAWINGS

[0019] In order to more clearly illustrate the technical solutions of the present application, the drawings needed to be used in the description of the present application will be briefly introduced as follows. Obviously, the drawings in the following description are only some embodiments of the present application, and all other drawings obtained by those skilled in the art without creative labor are within the scope of protection of the present application.

[0020] Figure 1 The overall structure schematic diagram of the normal pressure plasma discharge device provided by the present application is shown.

[0021] The reference signs in the drawings of the specification are as follows:

[0022] 1, device body; 2, gas inlet; 3, outlet; 4, dielectric electrode; 5, columnar accommodating cavity; 6, cooling hole; 7, turbulence structure. DETAILED DESCRIPTION

[0023] In order to make the purposes, characteristics and advantages of the present application more obvious and easy to understand, the present application will be further described in detail below in combination with the drawings and specific embodiments. Obviously, the described embodiments are some embodiments of the present application, not all embodiments. Based on the embodiments in the present application, all other embodiments obtained by those skilled in the art without creative labor are within the scope of protection of the present application.

[0024] The inventors find through analyzing the prior art that the existing atmospheric plasma itself has the characteristics of short and weak plasma beam, which makes it difficult to guarantee the uniformity and precision of the treatment effect when treating the surface of the material, and the treatment efficiency is also not ideal, which cannot meet the needs of large-scale high-quality production.

[0025] Please refer to Figure 1 , which shows a structural schematic diagram of an atmospheric plasma discharge device provided by the present application.

[0026] An atmospheric plasma discharge device comprises a device body 1, an air inlet 2, an outlet 3, and a dielectric electrode 4; the device body 1 is internally provided with a columnar accommodating cavity 5, and the dielectric electrode 4 is installed in the columnar accommodating cavity 5, and the dielectric electrode 4 is provided with a plurality of cooling holes 6; the device body 1 is provided with the air inlet 2 on the side close to the process gas input source, and the air inlet 2 is in communication with the columnar accommodating cavity 5; the device body 1 is provided with the outlet 3 on the side close to the workpiece to be treated, and the outlet 3 is in the form of a slit and is opened along the axial direction of the columnar accommodating cavity 5 and is in communication with the columnar accommodating cavity 5.

[0027] It should be noted that the columnar accommodating cavity 5 is arranged in the device body 1 to provide installation space for the dielectric electrode 4. The columnar structure helps to maintain the stability of the electric field distribution during the generation of plasma, and ensures the uniform generation and transmission of plasma in the cavity.

[0028] It should be noted that the dielectric electrode 4 is provided with a plurality of cooling holes 6, which can take away the heat generated by the electrode during the discharge process through the circulation of cooling medium (such as gas or liquid), avoid the damage of the electrode due to overheating, prolong the service life of the electrode, stabilize the performance of the electrode, and ensure the stability and continuity of the generated plasma.

[0029] It should be noted that the air inlet 2 is located on the side close to the process gas input source and is in communication with the columnar accommodating cavity 5. The air inlet 2 is used to introduce process gas, and these gases interact with the dielectric electrode 4 in the cavity and are ionized to generate plasma under the action of the electric field. The position and communication mode of the air inlet 2 ensure that the process gas can smoothly enter the device to participate in the reaction.

[0030] It should be noted that the outlet 3 is in the form of a slit and is opened along the axial direction of the columnar accommodating cavity 5 and is in communication with the cavity. The slit design makes the plasma form a specific distribution pattern when it is discharged from the device, which helps to achieve more uniform treatment effect when treating the surface of the workpiece to be treated, improves the treatment precision, and at the same time, the slit shape can also enhance the strength of the plasma beam and improve the treatment efficiency.

[0031] In the embodiments of this application, addressing the numerous shortcomings of existing plasma cleaning technologies in practical applications, which struggle to simultaneously achieve high efficiency, high precision, and low cost, this application provides an atmospheric pressure plasma discharge device. Specifically, it includes a device body 1, an inlet 2, an outlet 3, and a dielectric electrode 4. The device body 1 contains a cylindrical cavity 5, within which the dielectric electrode 4 is installed. The dielectric electrode 4 has multiple cooling holes 6. The inlet 2 is located on the side of the device body 1 closest to the process gas input source and communicates with the cylindrical cavity 5. The outlet 3 is located on the side of the device body 1 closest to the workpiece to be processed. The outlet 3 is slit-shaped and opens along the axial direction of the cylindrical cavity 5, communicating with it. The device's multiple cooling holes 6 on the dielectric electrode 4 effectively remove heat generated during discharge, preventing performance degradation or damage due to overheating. This not only maintains stable electrode operation and extends its service life but also ensures the stability and continuity of plasma generation, providing a stable plasma source for subsequent processing. The outlet 3 is opened in a slit shape along the axis of the cylindrical receiving cavity 5, which can generate a wide plasma beam. It can cover a larger area during the operation of the device, significantly improving the processing efficiency compared with the narrow beam plasma processing method, and can meet the needs of large-scale mass production.

[0032] The following will further describe an atmospheric pressure plasma discharge device in this exemplary embodiment. Please refer to [link / reference needed]. Figure 1 .

[0033] In one embodiment of this application, the plurality of cooling holes 6 are arranged in a circular array, and the spacing between adjacent cooling holes 6 is equal.

[0034] It should be noted that the circular array distribution ensures that the dielectric electrode 4 is heated uniformly in the circumferential direction. Since heat may be generated at various points on the surface of the dielectric electrode 4 during plasma discharge, this distribution ensures that the cooling medium (such as cooling gas or liquid) can uniformly contact all parts of the electrode, avoiding localized overheating. For example, during high-frequency plasma discharge, the electrode surface temperature rises rapidly; the circular array of cooling holes 6 allows the cooling gas to uniformly remove heat from all directions, maintaining a consistent electrode temperature.

[0035] It should be noted that the circular layout helps maintain the uniformity of the electric field around the electrodes. During plasma generation, the electric field distribution around the dielectric electrode 4 plays a crucial role in plasma generation and transport. The circular array of cooling holes 6 minimizes interference with the electric field caused by their arrangement, ensuring a uniform electric field distribution around the electrodes, thereby improving the stability and efficiency of plasma generation.

[0036] It should be noted that the equal spacing between adjacent cooling holes 6 ensures that each cooling hole 6 has substantially the same cooling effect on the surrounding area. During the cooling process, the cooling medium flows out of each cooling hole 6, forming a cooling area on the surface of the electrode with similar range and intensity. This avoids the problem of overcooling or insufficient cooling in some areas due to inconsistent spacing between cooling holes 6, resulting in more uniform temperature distribution across the entire electrode surface.

[0037] In an embodiment of the present application, the dielectric electrode 4 comprises a metal tube and a dielectric film wrapped around the outer surface of the metal tube.

[0038] It should be noted that the dielectric film can effectively isolate the metal tube from direct contact with the plasma and process gas. Plasma and some process gases have strong corrosive properties, and long-term contact can cause the metal tube to corrode and damage. The presence of the dielectric film can protect the metal tube, extend the service life of the electrode, and reduce the maintenance cost of the device.

[0039] In a specific embodiment, an alumina dielectric film is prepared on the outer surface of the metal tube using plasma spraying technology. First, the alumina powder is heated to a molten state, and then sprayed at high speed onto the rotating surface of the metal tube through a spray gun. It should be noted that there are many types of dielectric films, and different types of dielectric films play their own unique roles in atmospheric wide plasma discharge devices, mainly including the following categories:

[0040] Ceramic dielectric film: Alumina film is a typical representative. It has high hardness, high insulation and good chemical stability. In a plasma discharge device, it can effectively isolate the metal tube from the plasma, prevent the metal tube from being corroded, and at the same time promote the concentration of the electric field on the film surface, which is beneficial for the ionization of process gas to generate plasma. Yttria-stabilized zirconia (YSZ) film is also commonly used. It not only has excellent insulation performance, but also maintains a stable structure at high temperatures, has outstanding high-temperature resistance, and can withstand the high temperature generated during the plasma discharge process to ensure stable operation of the electrode.

[0041] Polymer dielectric film: Polytetrafluoroethylene (PTFE) film is widely used. It has excellent chemical stability and is almost not reactive with any chemical substances, resistant to strong corrosive substances such as acids and bases. At the same time, PTFE film has good insulation performance and low friction coefficient, and can be easily processed into various shapes to tightly wrap around the outer surface of the metal tube. Polyimide (PI) film also has excellent performance. It has high insulation, high temperature resistance and radiation resistance, and can maintain good mechanical properties at high temperatures, effectively protecting the metal tube and extending the service life of the electrode.

[0042] Glass dielectric film: borosilicate glass film is a common glass dielectric film. It has good insulation, chemical stability and optical transparency. In the plasma discharge device, the borosilicate glass film can effectively block the contact between the metal tube and the external environment, avoiding the corrosion of the metal tube. Its optical transparency facilitates the observation of the generation and reaction of the internal plasma by the operator, and the glass film can also adjust the electric field distribution to some extent, which is helpful to the uniform generation of plasma.

[0043] In an embodiment of the present application, the gas inlet 2 is communicated with the cylindrical accommodating cavity through a gas mixing channel. One end of the gas mixing channel is connected with the gas inlet 2, and the other end extends into the cylindrical accommodating cavity. The gas inlet 2 is provided with a valve.

[0044] It should be noted that the gas inlet 2 is communicated with the cylindrical accommodating cavity 5 through the gas mixing channel, so that the process gas entering the device can be fully mixed in the gas mixing channel. When multiple process gases enter from the gas inlet 2 at the same time, the special structure of the gas mixing channel can increase the contact area and contact time between the gases, promoting the uniform mixing of the gases. For example, when performing surface modification treatment of materials, argon and oxygen may need to be introduced at the same time, and the gas mixing channel can ensure that the two gases are uniformly mixed before entering the cylindrical accommodating cavity 5, thereby ensuring the consistency of the plasma treatment effect.

[0045] In an embodiment of the present application, the gas mixing channel is provided with a turbulence structure 7.

[0046] It should be noted that the turbulence structure 7 can enhance the mixing effect between multiple process gases entering the gas mixing channel, so that different gases can be more uniformly mixed, thereby improving the quality and stability of the generated plasma. In a specific embodiment, helical protrusions can be machined on the inner wall of the gas mixing channel; or multiple baffles can be arranged in the gas mixing channel in a staggered manner, which can be flat, arc-shaped or other shapes. The number, size and spacing of the baffles can be adjusted according to actual needs.

[0047] In an embodiment of the present application, a grounding metal part is further included; the grounding metal part is arranged around the outer periphery of the device body 1, and an insulating layer is arranged between the grounding metal part and the device body 1. The device body 1 is made of aluminum alloy or stainless steel material, and the inner wall of the device body 1 is polished to reduce the flow resistance of the process gas in the cylindrical accommodating cavity 5.

[0048] It should be noted that the plasma discharge process generates certain electromagnetic radiation, which may interfere with surrounding electronic equipment. The grounding metal part can act as an electromagnetic shield to confine the electromagnetic radiation inside the device and reduce the impact on the surrounding environment.

[0049] It should be noted that if the grounding metal part is in direct contact with the device body 1, when the device body 1 is electrified, the current may form a short circuit directly through the grounding metal part, affecting the normal operation of the device and even damaging the equipment. The presence of the insulating layer can prevent the current from flowing from the device body 1 to the grounding metal part, ensuring the electrical safety of the device.

[0050] It should be noted that when the process gas flows in the columnar containing cavity 5, the roughness of the inner wall will hinder the flow of the gas. After polishing treatment, the inner wall surface becomes smooth, the friction between the gas and the inner wall is reduced, thereby reducing the flow resistance of the process gas in the columnar containing cavity 5, enabling the gas to flow more smoothly, and improving the gas conveying efficiency.

[0051] Although the preferred embodiments of the present application have been described, those skilled in the art can make further changes and modifications to the embodiments once they know the basic inventive concept. Therefore, the appended claims are intended to cover all changes and modifications falling within the scope of the embodiments of the present application.

[0052] Finally, it should also be noted that in this paper, relational terms such as first and second are used only to distinguish one entity or operation from another, and do not necessarily require or imply that there is any such actual relationship or order between these entities or operations. Moreover, the terms "include", "contain" or any other variants thereof are intended to cover non-exclusive inclusion, so that the process, method, article or terminal device including a series of elements not only includes those elements, but also includes other elements not explicitly listed or inherent to such process, method, article or terminal device. Without more limitations, the element defined by the statement "including a" does not exclude the presence of other identical elements in the process, method, article or terminal device including the element.

[0053] The above describes in detail the atmospheric pressure plasma discharge device provided by the present application, and the principles and implementation modes of the present application are described by applying specific examples. The above description of the embodiments is only used to help understand the method of the present application and its core idea; at the same time, for those skilled in the art, according to the idea of the present application, there will be changes in specific implementation modes and application scope; in view of the above, the content of the specification should not be understood as a limitation of the present application.

Claims

1. An atmospheric pressure plasma discharge device, characterized by, The device comprises a device body, an air inlet, an outlet and a dielectric electrode. The device body is provided with a columnar accommodating cavity, and the dielectric electrode is installed in the columnar accommodating cavity and provided with a plurality of cooling holes. The device body is provided with the air inlet on the side close to the process gas input source, and the air inlet is communicated with the columnar accommodating cavity. The device body is provided with the outlet on the side close to the workpiece to be processed, and the outlet is in the form of a slit and is opened along the axial direction of the columnar accommodating cavity and communicated with the columnar accommodating cavity.

2. The atmospheric plasma discharge apparatus according to claim 1, wherein The plurality of cooling holes are distributed in a circular array, and the spacing between adjacent cooling holes is equal.

3. The atmospheric plasma discharge apparatus according to claim 1, wherein The dielectric electrode comprises a metal pipe and a dielectric film wrapped around the outer circumferential surface of the metal pipe.

4. The atmospheric plasma discharge apparatus according to claim 3, wherein The material of the dielectric film is one of ceramic, glass or quartz.

5. The atmospheric plasma discharge apparatus according to claim 1, wherein The air inlet is communicated with the columnar accommodating cavity through a gas mixing channel. One end of the gas mixing channel is connected with the air inlet, and the other end extends into the columnar accommodating cavity.

6. The atmospheric plasma discharge apparatus according to claim 5, wherein The gas mixing channel is provided with a turbulence structure.

7. The atmospheric pressure plasma discharge device according to claim 6, wherein The turbulence structure is a spiral protrusion arranged on the inner wall of the gas mixing channel or a staggered baffle.

8. The atmospheric plasma discharge apparatus according to claim 1, wherein The device further comprises a grounding metal piece. The grounding metal piece is arranged around the outer circumferential surface of the device body, and an insulating layer is arranged between the grounding metal piece and the device body.

9. The atmospheric plasma discharge apparatus according to claim 1, wherein The device body is made of aluminum alloy or stainless steel, and the inner wall of the device body is polished.

10. The atmospheric plasma discharge apparatus according to claim 1, wherein The air inlet is provided with a valve.

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