When the vacuum coating machine coats the substrate, sometimes there will be differences in film color. For processing manufacturers, this situation does not meet the standards of qualified products. Generally, products with film color differences are bad products. Therefore, manufacturers are also very concerned about the occurrence of this situation. Then, during the coating process of the vacuum coating machine, there is a difference in film color on the substrate. How to deal with it? There are generally two types of film color differences (excluding color spots) on the coated substrate. One is that the upper, middle and lower film colors of the entire mask are inconsistent, that is, the spectroscopic test curve is different; the second is that the single film color is inconsistent.

        The first type: the inconsistency of the upper, middle and lower film colors is called the uniformity of the whole umbrella (cover) is not good, also known as the umbrella difference. The main reason is that there is a problem with the uniformity correction plate (correction plate).
      The second: the deformation of the umbrella piece. It is also one of the reasons for the uneven color of the film, especially the umbrella piece that has been used for a long time. It used to be uniform, but it gradually becomes uneven, and the deformation of the umbrella piece may be the main reason.
      Third: the inconsistency of the film material condition, especially the sublimation and semi-sublimation film material being deflected, digging holes, etc. will also seriously affect the uniformity of the whole cover and single piece. Especially when there is a large number of manual pre-melting, the operation methods of each person are different, and the obtained material conditions will also be different.

The solution to the color difference of the coating film of the vacuum coating machine:
      First: Adjust the correction plate, try to consider the balance compatibility of high and low refractive index film materials, if there are two evaporation sources, if possible, use each correction plate independently to avoid interference.
      Second: if conditions permit, use planetary fixtures.
      Third: Umbrella piece shaping. For the umbrella piece shaping, you can first process an R base mold (select raw materials with higher strength), and then shape the umbrella piece on the base mold. In order to prevent the deformation of the umbrella pieces, the thickness of the umbrella pieces and the selection of raw materials should be appropriate when ordering the umbrella pieces.
      Fourth: Strengthen the management of umbrella pieces, especially the management during placement, to prevent deformation due to improper placement.
      Fifth: Improve the condition of the membrane material, especially when the electron gun is vapor-deposited for sublimation and semi-sublimation materials, the membrane material cannot be collapsed or pitted.
      Sixth: The film material that can be automatically pre-melted should be automatically pre-melted as much as possible to reduce the influence of human factors.