A part of the evaporated particles of the vacuum coating machine collides with the substrate and is reversed

A part of the evaporated particles of the vacuum coating machine collides with the substrate and is reversed

After the evaporated particles collide with the substrate, one part is reversed, and the other part is adsorbed. The surface diffusion of adatoms occurs on the surface of the substrate, and two-dimensional collisions occur between the deposited atoms to form clusters, some of which stay on the surface for a period of time and then evaporate. Clusters of atoms collide with diffusing atoms, or adsorb or release single atoms, and this process is repeated. When the number of atoms exceeds a certain criticality, it becomes a stable nucleus, and then continuously adsorbs other and compound atoms to gradually grow, and finally merges with the adjacent stable nucleus, and then becomes a continuous film.

The evaporation process of the vacuum coating machine continuously consumes the internal energy of the coating material

In order to escape from the surface of the plating material atoms or molecules in the liquid or solid phase of evaporation thermodynamics, they must obtain enough thermal energy and have a large enough thermal motion. When the kinetic energy of the velocity component of its vertical surface is sufficient to overcome the energy of mutual attraction between atoms or molecules, it is possible to escape from the surface and complete evaporation or sublimation. The higher the heating temperature, the greater the kinetic energy of the molecules and the greater the amount of particles that evaporate or sublime. The evaporation process continuously consumes the internal energy of the plating material. To maintain evaporation, the thermal energy of the plating material must be continuously supplied. Obviously, during the evaporation process, the amount of vaporization of the plating material (expressed as the vapor pressure above the plating material) is closely related to the heating (temperature rise) of the plating material. Therefore, the growth rate of the plating layer is closely related to the evaporation rate of the plating material.

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