Uneven film thickness of vacuum electroplating equipment

No matter how accurate the monitor is, it can only control the film thickness of a single point in the vacuum chamber, generally speaking, the middle position of the workpiece frame. If the film thickness of the vacuum plating equipment is not uniform at this location, the substrate far from the center will not achieve uniform thickness. Although the shielding cover can eliminate the long-term inhomogeneity, some film thickness variations are almost impossible to eliminate because of the instability of the evaporation source or the different behavior of the film material, but the proper selection of the vacuum chamber structure and evaporation source can make these effects less.

In the past few years, more and more users require coating system manufacturers to provide high-performance small specifications, simple optical coating system, at the same time, the user's performance requirements not only did not reduce, but improved, especially in the film density and ensure that the absorption of water after the spectral change of small and so on.

Now, the average size of the system is decreasing, and the production of optical coatings using small size equipment has become a purely technical issue. Therefore, the key to selecting a modern optical coating system depends on careful consideration of the expected performance of the coating product, the size and physical properties of the substrate, and all the technical factors required to ensure a highly consistent process.