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The role of plasma cleaning technology on the surface of the cathode panel

The role of plasma cleaning technology on the surface of the cathode panel

The role of plasma cleaning technology on the surface of the cathode panel: 　　Vacuum optoelectronic devices represented by low-light image intensifiers have a wide range of applications in national defense, scientific research and other industries, and have received widespread attention in China. The low-light image intensifier is mainly composed of cathode input window, multi-alkali photocathode, microchannel plate, phosphor screen, anode output window and other parts. Plasma cleaning technology Its working principle: Under low illumination at night, the scene image that cannot be directly seen by the human eye is converted into the corresponding photoelectron image through the multi-alkali photocathode on the cathode input window. The photoelectron image is amplified and enhanced by the microchannel plate electron multiplier , And then accelerated by the anode high voltage, converted by the fluorescent screen into an optical image with sufficient brightness, and output through the anode output window for human eyes to watch. 　　Multi-alkali photocathode is made by vacuum evaporation process. During production, four evaporation sources of Sb, K, Na and Cs are alternately evaporated to form a multi-alkali photocathode with Na2KSb (Cs) film. One of the main indicators of the low-light image intensifier is the sensitivity of the multi-alkali photocathode. Its level mainly depends on the growth quality of the Na2KSb(Cs) film, and the growth quality of the Na2KSb(Cs) film is in turn with the surface activity of the cathode panel. Cleanliness and so on are closely related. 　　 At the same time, if the surface of the cathode is not smooth or pure, it will also cause vacuum breakdown caused by field emission and damage the multi-alkali photocathode film. The main factors that cause vacuum discharge are: unevenness and microscopic bumps, free particles on the surface of the cathode panel, dielectric film, semiconductor film, additives on the cathode panel, and adsorbed gas. 　　 It is generally believed that the glass surface is divided into two layers: 　　 subsurface layer (Subsurface), that is, 0-100 nm below the surface, this layer has a large number of hydroxyl groups, and it has a strong affinity for water, so the glass surface adsorbs a large amount of water molecules (including a small amount of CO2). This part of the gas is not firmly bonded to the surface, which belongs to physical adsorption and weak chemical adsorption. Generally, when heated to about 150~200C in a vacuum, most of it can be desorbed from the glass within a few minutes. 　　Nearsurface, also known as weathered surface layer, the more alkaline oxide glass (such as soda glass, lead glass) has poor chemical stability of alkaline oxide and is susceptible to water vapor corrosion, so it is easier to weather. 　　The thickness of the weathered surface layer is generally a few microns. There is a large amount of gas, especially water, in the weathered surface layer. The weathered surface layer can be removed by soaking in a tartaric acid solution, or by plasma bombardment. 　　 tartaric acid solution soaking is to clean the organic cleaning solvent that is not easy to wash off, and also to clean the surface of the cathode panel. In this traditional process, in addition to using a large amount of tartaric acid solution, deionized water and alcohol, it also requires a longer processing time. Long-term use of this cleaning method is not only inefficient and wastes resources, but also has an impact on the environment and is not conducive to environmental protection. The working principle of plasma cleaning is to use a vacuum pump to evacuate the working chamber to a vacuum degree of 30~50Pa, and then ionize the gas under the action of the alternating electric field of the high-frequency generator to form a plasma state. Its remarkable feature is high uniformity Sexual glow discharge emits colored visible light from blue to deep purple according to different gases, and the material processing temperature is close to room temperature. 　　The active plasma performs the dual effects of physical bombardment and chemical reaction on the cleaned object, so that the surface material of the cleaned object becomes particles and gaseous substances, which are exhausted by vacuum to achieve the purpose of cleaning. 　　Plasma cleaning is a "dry" surface cleaning technology, applicable to various types of materials, such as metals, semiconductors, oxides and most polymer materials. At the same time, the geometry of the object to be cleaned is not limited, and the cleaning cost is much lower than that of wet cleaning. Only a few bottles of gas can replace thousands of kilograms of cleaning fluid. Plasma cleaning technology is used to treat the surface of the cathode panel, which can not only clean the surface of the cathode panel, but also increase the surface activity of the cathode panel, meet the production requirements of the multi-alkali photocathode, and make the growt

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Analysis of the discoloration of the semiconductor copper support in the vacuum plasma treatment system

Analysis of the discoloration of the semiconductor copper support in the vacuum plasma treatment system

Analysis of the discoloration of the semiconductor copper bracket in the vacuum plasma treatment system:         The semiconductor packaging industry, including the packaging of integrated circuits, discrete devices, sensors and optoelectronic devices, usually uses copper lead frames. In order to improve the reliability of welding and encapsulation, copper brackets are generally processed by a vacuum plasma processing system to remove the surface The organic substances and contaminants of this kind increase the solderability and adhesion of the surface. Vacuum plasma processing system         Sometimes we will find that the copper bracket is not handled properly in the vacuum environment of the vacuum plasma processing system, and the surface is prone to discoloration and blackening, and in severe cases, burning and other phenomena may occur. Is this because the air in the air chamber is not sucked up enough? After the oxygen molecules in the remaining air are excited, they chemically react with the copper surface to form oxygen plasma. The result is copper oxide? Is the reason really that simple? Combining many years of practical experience in plasma cleaning of copper brackets, Chengfeng Intelligent Manufacturing engineers will analyze it with you.         1. The vacuum degree of the plasma affects the cleaning effect and color change of the copper bracket:         The vacuum factor of the plasma cleaner related to the vacuum degree includes the leakage rate of the vacuum chamber, the background vacuum, the speed of the vacuum pump, and the air inlet flow rate. The faster the vacuum pumping speed, the lower the background vacuum value, the less air is left, and the less chances of the copper stent reacting with the oxygen plasma; when the process gas enters, the formed plasma can fully react with the copper stent. The non-excited process gas can easily take away the reactants, and the copper support has a good cleaning effect and is not easy to fade.         2. The influence of the power of the vacuum plasma treatment system on the cleaning effect and discoloration of the copper bracket:         The related factors of vacuum plasma processing system power include energy power and unit power density. The greater the power, the higher the plasma energy, and the greater the bombardment force on the surface of the copper stent; when the power is the same, the fewer copper stents are processed, the greater the unit power density, the better the cleaning effect, but there is also excess energy. The risk of discoloration or burning of the board surface.         3. The influence of the electrode of the vacuum plasma treatment system on the discoloration of the copper bracket:         The plasma distribution of the vacuum plasma processing system is related to factors such as the electrode structure, the direction of the air flow, and the placement of the copper bracket. Due to different processing materials, process requirements and capacity requirements, the electrode structure design is also different; therefore, the gas field formed by the gas flow in the electrode affects the plasma movement, reaction, and uniformity; the placement of the copper bracket affects the electric field And the characteristics of the gas field, leading to unbalanced energy distribution, local plasma density is too high, burning sintering.         Experimental results show that the processing time, power frequency, and equipment type of the vacuum plasma processing system will affect the processing effect and color of the copper bracket.

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What is a plasma cleaning machine? Is it a plasma cleaning tool? Company News

What is a plasma cleaning machine? Is it a plasma cleaning tool? Company News

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What are the benefits of the plasma cleaning dispenser

What are the benefits of the plasma cleaning dispenser

Plasma cleaning dispenser is a kind of equipment that combines plasma cleaning machine and dispensing process. With the development in recent years, the process has become more and more mature, so is the plasma cleaning dispenser good? What characteristics will it have? Next, the editor of Chengfengzhi's 20-year plasma manufacturer will introduce to you. Plasma cleaning dispenser         The utility model combines a plasma cleaning machine and an automatic glue dispensing machine, and integrates plasma surface treatment and glue dispensing technology, so that the plasma cleaning glue dispensing machine has been applied in more and more practical applications, especially for some future applications. After processing the products with poor performance and poor performance, dispensing immediately after plasma cleaning can achieve a better dispensing effect. That is just one of the advantages of plasma cleaning dispensers, so what are the specific functional characteristics?         The plasma cleaning machine installed on the plasma cleaning dispenser can effectively remove dirt that is difficult to see with the naked eye, mainly including organic matter, oil, dust, etc. In addition to surface cleaning, it can also improve the wettability of the surface of the processed material , Increase the surface roughness of the material, increase the contact area between the glue and the material surface, remove the organic matter, oil and even dirt that the material can’t see with the naked eye, improve the wettability of the material surface, increase the surface roughness, and make the glue and the material The bond between is stronger.         For some materials with poor surface energy, such as PP polypropylene, PE polyester, ETFE ethylene-tetrafluoroethylene copolymer, PMMA acrylic, EPDM EPDM, etc., plasma cleaning dispensing can also improve the surface glue of the material Reliability, durability and peel resistance of bonding.         After the automatic integrated processing of the plasma cleaning dispenser, the consistency of the material dispensing is good, and the phenomenon of wire drawing, glue overflow, and glue breaking is not easy to occur, which can effectively reduce the delamination caused by air bubbles.         If you want to know more, please feel free to call us, and we will answer your questions about the plasma cleaning dispenser for free.

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Plasma cleaning machine plasma cleaning connector aviation application

Plasma cleaning machine plasma cleaning connector aviation application

At present, many related products will use plasma cleaning machine for surface treatment. Aerospace connector is one of them. Chengfeng Zhizao has accumulated rich experience in this area.         High-precision fields such as aviation and aerospace generally have higher product requirements, and plasma cleaners are required to perform surface treatment on connectors and some metal parts. Next, take the connector as an example to introduce the related processing technology of plasma cleaning connector in aviation and other fields. Plasma cleaning connector         Generally, the connectors used in aviation and other fields are relatively small, mainly including fluorosilicone rubber FVMQ connectors, thermoplastic polyester PBT connectors, polyphenylene sulfide plastic PPS connectors, polyetheramide PEI connectors, etc., for bonding and printing The requirement of plasma cleaning machine is high. The original wiping and special glue bonding are replaced by plasma cleaning machine pretreatment, which can not only meet the environmental protection requirements, but also improve the reliability and consistency of the treatment.         Using a plasma cleaner to clean the connector base can remove silicone oil or release agent from the surface of the connector, improve the surface cleanliness of the product, and also improve the surface energy of the base, and improve the adhesion and reliability of the silk-screened characters. It can improve the printing and bonding effect of the connector. The change in the angle of the water droplets before and after the connector product base was processed by the plasma cleaner. The angle of the connector base was changed from 121 degrees to 50.8 degrees, and the aviation connector base was changed from 103.99 degrees to 53.6 degrees.         For the plasma surface treatment of aerospace products, there are two points worth noting:         1. The hydrophilic groups produced during the activation process of the plasma cleaner are easy to disappear with time. Therefore, after the plasma cleaner is processed, the subsequent treatment shall be carried out as soon as possible;         2. The process parameters used in plasma cleaning machine processing will be selected according to the different materials. In terms of parameter control, it is also an inspection of the equipment manufacturer's ability.         If you want to know more, please feel free to inquire at any time, and we will answer your questions about handling connector processing for free.

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Low-temperature plasma treatment makes difficult-to-stick plastics no longer difficult, and Chengfeng Zhizhi is the trusted choice

Low-temperature plasma treatment makes difficult-to-stick plastics no longer difficult, and Chengfeng Zhizhi is the trusted choice

Plasma is composed of electrons, positive ions and neutral particles (including all uncharged particles, such as atoms, molecules and atomic groups, etc.), an ionized gas that is neutral to the outside world. Plasma is called the fourth state in which matter exists in addition to solid, liquid and gaseous states. There are four main forms of low-temperature plasma treatment. Low-temperature plasma treatment of plastics        1. Surface etching        Under the action of plasma, some chemical bonds on the surface of the material are broken, forming small molecular products or being oxidized to CO, CO2, etc. These products are pumped away by the pumping process, making the surface of the material uneven and increasing the roughness.        2. Surface activation        Under the action of low-temperature plasma treatment, some active atoms, free radicals and unsaturated bonds appear on the surface of hard-to-stick plastics. These active groups will react with active particles in the plasma to generate new active groups. However, materials with active groups will be affected by the action of oxygen or the movement of molecular chains, which will cause the surface active groups to disappear. Therefore, the surface activity of plasma-treated materials has a certain time effect.        3. Surface grafting        In the surface modification of materials by plasma, due to the effect of active particles on the surface molecules in the plasma, the surface molecular chains are broken to generate new free radicals, double bonds and other active groups, and surface cross-linking, grafting, etc. occur. reaction.        4. Surface polymerization        When using organic fluorine, organic silicon or organic metal as plasma active gas, low-temperature plasma treatment will polymerize and produce a deposition layer on the surface of the material. The existence of the deposition layer is beneficial to improve the bonding ability of the material surface.        Non-stick plastics mainly refer to polyolefins such as polyethylene (PE) and polypropylene (PP) and fluorine-containing plastics such as polytetrafluoroethylene (PTFE) and perfluoroethylene propylene (FEP). This type of plastic usually has advantages that other polymer materials do not have. Polyolefin plastics such as PE are low in cost, excellent in performance, and easy to process into various profiles, so they are widely used in daily life; and PTFE, commonly known as the plastic king, is a plastic with very good comprehensive properties and has excellent heat resistance. , Cold resistance and chemical resistance, it is widely used in the electronics industry and some cutting-edge fields.        Why is hard-to-stick plastic so hard to stick?        1.1 Low surface energy and poor wetting ability        The basic condition for forming a bonding state between the surface of any material and the adhesive is that a thermodynamic bonding state must be formed. It depends on the degree of wetting (contact angle) between the surface of the material and the adhesive, the surface tension of the adhered material, the surface tension of the adhesive, and the surface tension between the adhered material and the adhesive. The surface energy of hard-to-stick plastics is relatively low, so its wetting ability is poor.        1.2 High crystallinity        The molecular chains of difficult-to-stick plastics have regular structure, high crystallinity, and good chemical stability. Their swelling and dissolution are more difficult than non-crystalline polymers. When bonded with solvent-based adhesives, it is difficult to diffuse polymer molecular chains. And entangled with each other and cannot form a strong adhesion force.        1.3 The molecular chain is non-polar        PE molecular chain does not have any polar groups and is a non-polar polymer; PP molecular structure unit has -CH3, but -CHs is a very weak polar group, so PP is basically a non-polar polymer; PTFE Fluoroplastics are also non-polar polymers due to their highly symmetrical structure. Adhesives adsorbed on the surface of these difficult-to-stick plastics can only form a weak dispersion force, but lack the orientation and induction force, so the adhesion performance is poor.        1.4 There is a weak boundary layer        In addition to structural reasons that difficult-to-stick plastics are difficult to stick, they also lie in the presence of a weak boundary layer on the surface of the material. This weak boundary layer comes from the low-molecular components of the polymer itself, various additives added during the polymerization process, as well as human impurities during processing, storage and transportation.        Such small molecular substances are very easy to precipitate and collect on the surface of the plastic, forming a weak interface layer with very low strength. The existence of this weak boundary layer greatly reduces the bonding strength of the plastic.       Low-temperature plasma treatment surfac

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