Last time, I introduced the principle, application, design, etc. of the pvd coating machine to you. Today, the editor of Huicheng Vacuum will introduce the chemical composition of the vacuum coating in detail to you, so that everyone can have a deeper understanding of the pvd coating machine. First of all, let's introduce the three-point uniformity of the pvd coating machine:

1. Uniformity in thickness: It can also be understood as roughness. On the scale of optical films (that is, 1/10 wavelength as a unit, about 100A), the uniformity of vacuum coating is quite good, and the roughness can be easily removed. The degree of control is within 1/10 of the wavelength of visible light, that is to say, there is no obstacle to the optical properties of the film, but if it refers to the uniformity on the atomic layer scale, that is to say to achieve 10A or even 1A. The surface is flat, and the specific control factors will be explained in detail below according to different coatings.
2. Uniformity of chemical composition: That is to say, in the film, the atomic composition of the compound will easily produce uneven characteristics due to the small scale. If the coating process of SiTiO3 film is unscientific, the composition of the actual surface will not be the same. It is not SiTiO3, but may be other ratios. The coating film is not the chemical composition of the desired film, which is also the technical content of vacuum coating. The specific factors are also given below.
       3. Uniformity of lattice order: This determines whether the film is single crystal, polycrystalline or amorphous, which is a hot issue in vacuum coating technology. The oxide coating process is very complicated, but the main influencing factors are the cohesion of the coating material, the adsorption force between the coating and the substrate, and the temperature of the substrate, and the three are interrelated and restricted.
      When the vapor stream emitted from the evaporation source is separated from the surface of the evaporation material, the temperature is very high and the energy is relatively high. During the process of rising through the evaporation area to reach the surface of the substrate, the kinetic energy decreases due to collision and energy exchange in motion, and reaches the substrate. The particles on the surface of the material quickly exchange energy with the substrate and are quickly deposited on its surface. In the coating process, ion bombardment improves the surface of the substrate, and auxiliary means such as establishing plasma gas in the evaporation area to improve the function of vaporized particles can better solve the problem of bonding firmness between the coating and the substrate. In fact, among many coating processes, the oxide coating process and procedures are very difficult, because it faces many factors, environment and materials, etc., but the oxide coating process is produced by the majority of enterprises. Favorite. Therefore, the development trend of this coating process and equipment will get better and better!
       The above is the industry knowledge related to pvd coating machine that Huicheng Xiaobian represents for you today, I hope it can help you.