No matter how it can only monitor the accuracy and control of vacuum room single point position of the film thickness is generally the middle position of the workpiece frame. If the film thickness of the vacuum plating equipment is not absolutely uniform, then the substrate away from the central position can not get a uniform thickness. Although the shielding cover can eliminate the uniformity of performance is not long, but some changes in film thickness is different from instability or membrane evaporation source caused by, so it is almost impossible to eliminate, but the proper structure and source of the vacuum chamber can make these impact minimization.
In the past few years, more and more users require coating system manufacturers to provide small and simple optical coating system, high performance at the same time, the user demand of performance is not reduced, but increased, especially in the film density and ensure the water after the spectral changes minimization etc.
Now, the average size of the system specifications have been reduced, and the application of small size equipment for optical coating production has also become a pure technical problem. Therefore, the key depends on the selection of modern optical coating system to the following factors: to seriously consider the expected performance of coating products, size and physical properties of the substrate and to ensure that all technical factors necessary to process high consistency.