Vacuum coating-basic knowledge of vacuum coating
　 The vacuum coating is completed by a special vacuum coating machine. The working process and principle are: the substrate is transported by the manipulator of the coating machine and enters the vacuum chamber of the coating machine, and the argon ions after high-voltage ionization are in a strong electric field and a strong magnetic field. Under the action of, it produces high-speed motion, bombards the surface of the target material, and the excited metal ions adhere to the surface of the substrate to form a reflective film.
Basic knowledge of vacuum coating:
1. Vacuum: Use a vacuum pump to pump out the gas in the container to make the gas in the space below one atmospheric pressure, that is, the density of gas molecules in the space is lower than the density of gas molecules in the area at the atmospheric pressure.
2. The thinness of the residual gas in the vacuum is the degree of vacuum, that is, the degree of vacuum. Usually expressed in pressure unit (Pa)
3.1Pa is the pressure of 1N acting on the area of 1m2. 1 atmosphere pressure=1.03×105Pa
4. Pressure rise rate: the rate at which the degree of vacuum decreases per unit time. Unit: Pa/h
5. The pumping speed of the vacuum pump is referred to as the pumping speed (unit: L/S): When the pump is equipped with a standard test cover and works under the specified conditions, the gas flow through the test cover is measured at the designated position on the test cover Balance the pressure ratio.
6. Ultimate vacuum degree: (unit: Pa): work under the specified conditions, under the condition of normal work without introducing gas, the lowest pressure tends to be stable