The influence of vacuum coating environment on products is very important, and the surface cleaning treatment of vacuum coating products is very important. Before the products enter the coating room, they should be cleaned carefully to achieve the purpose of degreasing, decontamination and dehydration. The surface pollution of substrate comes from various kinds of dust, lubricating oil, engine oil, polishing paste, grease, perspiration, etc; Oxide film formed on the surface of parts in humid air; Gas absorbed and adsorbed on the surface of parts. These contaminants can basically be removed by degreasing or chemical cleaning.
For the cleaned surface after cleaning treatment, it should not be stored in the atmospheric environment, but should be stored in closed containers or cleaning cabinets to reduce the contamination of dust. The adsorption of hydrocarbon vapor can be minimized by storing the glass substrate in a newly oxidized aluminum container. Because these containers preferentially absorb hydrocarbons. For highly unstable and water vapor sensitive surface, it should be stored in vacuum drying oven. Cleaning the dust in the coating room, setting up a clean workshop and keeping the room clean are the basic requirements of the coating process for the environment. In areas with high air humidity, in addition to cleaning the substrate and parts in the vacuum chamber carefully before plating, baking and degassing should also be carried out. To prevent the oil from entering the vacuum chamber, pay attention to the oil return from the oil diffusion pump, and take oil blocking measures for the diffusion pump with high heating power.