With the development of coating technology, various vacuum coating machines have gradually appeared. No matter which kind of vacuum coating machine, the uniformity of the film will be affected by some factors. Now, we use the magnetic sputtering vacuum coater to analyze the factors of uneven film formation.
Uneven air extraction from the coating machine will affect the uniformity of the coating. It is important that the substrate is clean. Before vacuum coating, the surface of the substrate must be carefully cleaned to achieve the purpose of degreasing, decontamination and dehydration of the workpiece. The surface contamination of the substrate is from various dust, grease, polishing paste, sweat stains, etc. attached to the parts during processing and transportation. In a humid environment, the surface of the substrate is easily oxidized, forming an oxide film to adsorb gas. These dirts can be cleaned by degreasing or chemical methods. The clean substrate should not be placed directly outside, it needs to be stored in a closed container to reduce contamination. Dust will accumulate in the coating room, so it is necessary to clean the coating room, bake and degas, and place the machine in a clean environment. Pay attention to the oil return of the diffusion pump. There are many raw materials for coating, such as resin, silicone, silicon hydrochloric acid, polymer, etc. The ratio of auxiliary materials and formulas is different, and the film is also different.
The above are the factors that cause uneven film formation by vacuum coating machines.