Due to the particularity of the vacuum evaporation process, it has the following requirements for the substrate to be coated: 1. Good heat resistance, the substrate must be able to withstand the radiant heat of the evaporation source and the latent heat of condensation of the evaporation; 2. From The volatile substances generated on the film substrate should be less; for the substrate with high hygroscopicity, it should be dried before evaporation; 3. The substrate should have a certain strength; 4. Good adhesion to the evaporation layer; 5 . For non-polar materials such as PPPE, surface treatment should be carried out before evaporation to improve the adhesion fastness of the coating. Oh