We often hear professionals say that when purchasing vacuum coating machine equipment, we must choose a machine with multiple gas outlets, but we don't know what multi-channel gas means, and what the gas has in the process of coating The role of the gas, the following is a small series to introduce in detail the role of the gas when the real start-up coating machine is running.

Any solid material will dissolve and adsorb some gases in the atmospheric environment, and when the material is placed in a vacuum state, it will release gas due to desorption and desorption. The rate of outgassing is proportional to the gas content in the material. Different materials decompose the gas composition and desorption temperature and time are different.
Different pumps have different pumping rates for gases with different compositions. When vacuuming, the atmosphere in the container is first pumped out (this part of the gas is quickly pumped away, and the gas in the furnace is basically exhausted at 10-1Pa), and then the gas desorbed from the surface of the material and the inside of the material diffuse out to the surface. Therefore, after the goods enter the furnace, heat preservation and degassing must be carried out, because the goods will absorb some impurity gases before entering the furnace, and we need to heat them properly to make these The gas resolves the surface of the desorbed goods. Taking stainless steel as an example, in addition to the gas adsorbed on its surface, some gases will be precipitated inside the steel during the continuous heating and heat preservation process. Adhesion is also greatly affected.
        Therefore, when the vacuum coating machine coats the film, the quality of the film layer and the gas play a key role, which is an indispensable step in the coating process.