The return flow in the vacuum chamber of the vacuum evaporation coating equipment is directly proportional to the conductance of the pumping pipe, the pumping time, and the oil return rate of the unit. Therefore, the oil return rate of domestically made vacuum pumps is generally higher. This is because the longer the pumping time of the low-temperature vacuum chamber, the greater its return flow.

Physical Vapor Deposition (PVD for short) is a technology that uses physical methods to deposit thin films on substrates. The main function of the cooling system of the physical vapor deposition equipment is to cool the equipment parts, such as the vacuum pump set, the oil diffusion pump, the wall of the reaction chamber, the target source, etc. In order to achieve the overall cooling effect of the equipment, the current PVD equipment generally adopts flow channel cooling. Generally, for the parts that need to be cooled, due to the consideration of the need for anti-corrosion function, such parts are usually made of stainless steel or other Materials with strong corrosion resistance. The ice water machine pumps the cooled water into the above-mentioned components that need to be cooled, and finally returns to the ice water machine through the corresponding pipeline after cooling to realize a cooling water cycle. However, in the actual production process, due to the quality of the cooling water used and other unknown reasons, the above-mentioned cooling water pipelines such as the outer wall of the reaction chamber and the outer wall of the diffusion pump, especially the target source and other components, are caused by dirt precipitation. A common situation is that the yellow suspended solids produced after corrosion are dispersed in the cooling water, and enter all the above-mentioned components that need to be cooled with the cooling water and gradually deposit in them, resulting in a decrease in the effective cooling water flow rate and affecting the cooling effect. For the above-mentioned corrosives deposited in the cooling pipe on the outer wall of the diffusion pump and the liquid storage cavity of the reaction chamber, the usual method is to disassemble the target source for major cleaning and maintenance, which will consume more labor costs and easily cause Loss of work stoppage.