Environmental requirements of vacuum coating

With the rapid growth of coating technology, various types of vacuum coating machines have begun to appear gradually. However, in terms of film uniformity, the uniformity of films deposited by all vacuum equipment will be affected by some factors. Therefore, vacuum coating has certain requirements on the environment.

It is very important to clean the surface of substrate in vacuum coating process. Before the substrate enters the coating chamber, the substrate should be carefully cleaned before plating to achieve the purpose of degreasing, decontamination and dehydration.

The surface pollution of substrate comes from all kinds of dust, lubricating oil, oil, polishing paste, grease, sweat, etc. adhered to the parts in the process of processing, transmission and packaging; the oxide film formed on the surface of the part in humid air; and the gas absorbed and absorbed on the surface of the part. Vacuum coating manufacturers can basically use degreasing or chemical cleaning methods to remove these dirt.

Clean surface after cleaning treatment can not be stored in atmospheric environment, but should be stored in closed container or cleaning cabinet to reduce dust contamination. The adsorption of hydrocarbon vapor can be minimized by storing the glass substrate in a freshly oxidized aluminum container. Because these containers are limited in absorbing hydrocarbons. For highly unstable and water vapor sensitive surfaces, they should be stored in a vacuum drying oven.

Cleaning the dust in the coating room, setting up a high cleanliness workshop and keeping the room highly clean are the basic requirements of the coating process on the environment. In areas with high air humidity, the substrate and various parts in the vacuum chamber should be cleaned carefully before plating, and baking and degassing should also be carried out. In order to prevent oil from entering the vacuum chamber, pay attention to the oil return from the oil diffusion pump, and take oil retaining measures for the diffusion pump with high heating power.