1. Vacuum coating equipment should be cleaned each 200 times coating processes. The method is repeatedly scrubbing the vacuum chamber wall with a saturated solution of caustic soda (NaOH), (note that human skin cannot be directly contacted with caustic soda solution to avoid burns). The purpose is to making the coated materials react with NaOH to make layer falls off and releases hydrogen. Then clean the vacuum chamber with clean water and dip the dirt inside the suction valve with a cloth soaked in gasoline.
2. When the roughing pump (slide valve pump, rotary vane pump) works continuously for one month (half a month if the rainy season), new oil needs to be replaced. The method is opening the oil bolt and giving off the old oil, and then turn on the pump for several seconds to completely discharge the old oil in the pump. Then twist the oil bolt and add new oil to the rated capacity (observed by the oil sight glass). After using for more than half a year continuously, open the oil cover and clean the inside of the box with a cloth when replace the oil.
3. After continuously using for more than 6 months, the pumping speed of diffusion pump will be significantly slowed down, or come across improper operation. Please fill the pump with the atmosphere, remove the connected water pipe, remove the electric furnace plate, and twist the first-level nozzle out. Clean the pump chamber and cylinder block with gasoline, and then clean them again with washing powder, at last wash it again thoroughly with clean water. After the water has evaporated, install the cylinder block, add new diffusion pump oil, and put it back in the machine, connect the water pipe and install the electric furnace, then turn on the pump. Before restarting, pay attention to leak detection. The method is turning on the holding pump, close the door, and observe whether the partial vacuum of the diffusion pump reaches 6X10 Pa after a few minutes, otherwise perform leak detection. Check whether the seal is installed at the joint or the seal is crushed. Remove heat hazards before heating, otherwise diffusion pump oil will be burned and unable to operate.