Plasma cleaning machine gas action

• Categories:Technical Support
• Author:plasma cleaning machine-surface treatment equipment-CRF plasma machine-Sing Fung Intelligent Manufacturing
• Origin:
• Time of issue:2020-11-20
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(Summary description)Before using the plasma cleaning machine to clean the object, the object and dirt should be analyzed first, and then select the corresponding gas. According to the action principle of plasma, the selected gases can be divided into two types, one is hydrogen, oxygen and other reactive gases, among which hydrogen is mainly used to clean oxides on the metal surface for reduction reaction. The oxygen introduced by the plasma cleaner is mainly used to clean the organic matter on the surface of the object.   The other is plasma cleaner filled with argon, helium, nitrogen and other non-reactive gases. Nitrogen plasma treatment can improve the hardness and wear resistance of the material. Argon and helium are stable, and the discharge voltage is low (the ionization energy of argon atom is 15.57eV), and metastable atoms are easy to form. On the one hand, the plasma cleaning machine USES the physical action of its high-energy particles to clean the objects that are easy to be oxidized or reduced. Ar+ bombarding dirt forms volatile dirt, which is removed by vacuum pump to avoid the reaction of surface substances. On the other hand, metastable atoms are easily formed by argon, and then charge conversion and combination occur when they collide with oxygen and hydrogen molecules, forming oxygen and hydrogen active atoms acting on the surface of the object.   Although it is effective to clean the surface oxides with pure hydrogen in the plasma cleaning machine, the stability and safety of discharge are mainly considered here, and the mixture of argon and hydrogen gas is more suitable for the plasma cleaning machine. In addition, for the material easy oxidation or easy reduction of the material plasma cleaning machine can also be used to reverse the oxygen and argon hydrogen gas cleaning order to achieve the purpose of thorough cleaning.   Application examples of gas in plasma cleaning machine:   1. Degreasing and cleaning of metal surface:   Metal surface often has grease, grease, oxide layer and other organic matter. Prior to sputtering, painting, bonding, bonding, brazing, and PVD and CVD coatings, plasma treatment is required to obtain a completely clean and oxide free surface. In this case, plasma treatment has the following effects:   Oxide removal:   Metal oxides react with the treated gases. The treatment USES hydrogen or a mixture of hydrogen and argon. Sometimes two steps are used, one is to oxidize the surface with oxygen for 5 minutes, the second is to remove the oxide layer with a mixture of hydrogen and argon, or several gases can be used simultaneously.   2. Plasma etching:   In the plasma etching process, the etched object will change into a gas phase under the action of the processing gas, the processing gas and matrix materials are pumped out, and the surface is continuously covered by the fresh processing gas. The unneeded etched parts should be covered with a material (for example, chromium is used as a covering material in the semiconductor industry).   Plasmas are also used to etch plastic surfaces into which the filling mixture can be oxidized by oxygen. Etching methods such as polyformaldehyde, polyphenylene sulfide, and polytetrafluoroethylene are pretreated in their printing and bonding, and plasma treatment can greatly increase the bonding wetting area.   3. Etching and ashing:   PTFE etching:   Teflon cannot be printed or bonded without treatment. It is well known that active alkali metals can increase adhesion, but this method is not easy to master and the solution is toxic. Using the plasma method can not only protect the environment, but also achieve better results. The plasma structure can enlarge the surface and form an active layer on the surface, so that PTFE can be better adhesive printing.   Etching of PTFE mixture:   The PTFE mixture must be etched very carefully to avoid overexposure of the filler, thereby weakening adhesion. The treated gases may be oxygen, hydrogen and argon. It can be used in polyethylene, polytetrafluoroethylene, thermoplastic elastomer, polyformaldehyde, etc.   4. Surface activation and cleaning of plastics, glass and ceramics:   Like polypropylene and polytetrafluoroethylene, plastics, glass and ceramics are not polar, so these materials should be processed before printing, bonding and painting. At the same time, the glass and ceramics surface slight metal contamination can also be cleaned with plasma. Compared with combustion treatment, plasma treatment does not damage samples. At the same time, the whole surface can be treated uniformly, without poisonous gas generation, and hollow and interstitial samples can be treated.   Commonly used plasma cleaning machine gas: compressed air, oxygen, argon, argon mixed gas, CF4 and so on.