Vacuum coating equipment mainly refers to a kind of coating that needs to be carried out under high vacuum, including many kinds, including vacuum ion evaporation, magnetron sputtering, MBE molecular beam epitaxy, PLD laser sputtering deposition and so on. The main idea is divided into evaporation and sputtering.

What needs to be coated is called substrate, and the plated material is called target. The substrate and the target are in the same vacuum cavity.
Evaporation coating is generally to heat the target material to make the surface components evaporate in the form of atomic clusters or ions, and settle on the surface of the substrate to form a film through the film-forming process (scatter island structure vagal structure layer growth). For sputtered coating, it can be simply understood as bombarding the target with electrons or high-energy laser, making the surface components sputtered out in the form of atomic clusters or ions, and finally deposited on the surface of the substrate, experiencing the film-forming process, and finally forming a film.
Maintenance and maintenance
1. The vacuum coating equipment should clean the working room once every 200 coating procedures. The method is as follows: repeatedly scrub the vacuum chamber wall with NaOH saturated solution (pay attention to that the human skin can not directly contact the NaOH solution to avoid burning). The purpose is to make the aluminum (AL) plated on the film react with NaOH, and the film will fall off after the reaction and release hydrogen. Then clean the vacuum chamber with clean water and clean the dirt in the fine extraction valve with cloth stained with gasoline
2. When the roughing pump (slide valve pump, rotary vane pump) works continuously for one month (half in rainy season), it needs to be replaced with new oil. The method is: screw the open oil bolt, drain the old oil, and then start the pump for a few seconds, so that the old oil in the pump is completely discharged. Screw the oil bolt and add new oil to the oil level (oil sight glass observation). If it has been used continuously for more than half a year, open the oil cover when changing the oil and clean the dirt in the box with a cloth.
3. If the diffusion pump has been used continuously for more than 6 months, the pumping speed obviously slows down, or the operation is improper. Fill it into the atmosphere, remove the connecting pipe, remove the electric stove plate, screw out the primary nozzle, clean the pump chamber and pump tank with gasoline, then wash it with washing powder mixed with water, and then clean it thoroughly with clean water. After the water evaporates, install the pump tank and add new diffusion pump oil, And install the machine body, connect the water pipe, install the electric stove plate, and then restart the machine. Pay attention to leak detection before restart. The method is: start the maintenance pump, close the door, after a few minutes, observe whether the vacuum degree of the diffusion pump reaches 6x10pa, otherwise it is necessary to carry out leakage detection. Check whether the joint is equipped with sealing rubber ring, or the sealing ring is crushed. Remove the hidden danger of air leakage before heating, otherwise the diffusion pump oil will burn ring, unable to enter the working state.