pvd coating machine has a part called cryogenic capture pump, the general professional vacuum coating personnel did not mention this part, many people almost do not know such a part, then cryogenic capture pump in the pvd coating machine in the end what role? The following Huicheng vacuum editor introduces the application principle of vacuum coating machine cryogenic trap pump, hoping to help you:

In the high vacuum environment, there is a certain residual gas. Because the molecular weight of water is smaller than the molecular weight of the main components of air such as oxygen and nitrogen, therefore, whether it is an oil diffusion pump or a molecular pump, it can not be quickly and effectively extracted, so it accumulates more and more, and finally becomes the remaining gas accounting for 65% to 95% of the residual gas;
At the same time, due to the inevitable evaporation of pump oil during the use of vacuum pump, there will be a small amount of oil vapor into the vacuum system.
Due to the existence of water vapor and oil vapor, the vacuum system can not quickly reach the vacuum required by the customer, resulting in a longer vacuum time and decreased production efficiency, the higher the required vacuum degree, the greater the environmental humidity, the more obvious the impact.
At the same time, the existence of water vapor and oil vapor will lead to a decline in the firmness of the film layer, unable to multilayer coating, and uneven color.
Water vapor will also ionize under certain conditions, produce oxygen, oxidize the target, and cause the color of the coating to change. The higher the ambient humidity, the higher the temperature, and the higher the required vacuum degree, the greater the impact. Therefore, water vapor and oil vapor are the main harmful gases in the field of pvd coating machine coating and high vacuum acquisition.