PVD coating machine  Vacuum evaporation coating (evaporation for short) is the earliest developed and widely used coating technology in PVD technology. Although sputtering and ion plating developed later are superior to evaporation in many aspects, vacuum evaporation technology still has many advantages, such as relatively simple equipment and process, which can produce very pure film and prepare Films with specific structures and properties are still very important coating technologies today. In recent years, due to the wide application of electron bombardment evaporation, high-frequency induction evaporation and laser evaporation in evaporation coating technology, this technology has become more perfect.

       The film material is placed in a vacuum coating chamber and heated by the evaporation source to evaporate. When the mean free path of the evaporating molecules is greater than the linear size of the vacuum coating chamber, the atoms and molecules of the vapor escape from the surface of the evaporation source. The impact of molecules or atoms can directly reach the surface of the substrate to be plated. Due to the low temperature of the substrate, it will condense on it to form a film. In order to improve the adhesion of the evaporated molecules to the substrate, the substrate is appropriately heated necessary. In order for the evaporation coating to proceed smoothly, the vacuum conditions in the evaporation process and the evaporation conditions in the film forming process should be available.
       Vacuum conditions in the evaporation process: When the mean free path of vapor molecules in the vacuum coating chamber is greater than the distance between the evaporation source and the substrate (called the evaporation distance), sufficient vacuum conditions will be obtained. For this reason, it is necessary to increase the mean free path of the residual gas to reduce the collision probability of vapor molecules and residual gas molecules. It is very necessary to pump the vacuum coating chamber into a high vacuum.
       In the vacuum coating process, the higher the vacuum degree is not the better, because when the vacuum degree in the vacuum coating chamber exceeds 10-6Pa, the vacuum system must be baked to degas to achieve. Because baking and degassing will cause contamination of the substrate, the film can be formed under high vacuum of 10-5 Pa without baking and degassing. The quality of the film is not necessarily better than that of the film prepared under ultra-high vacuum. The poor quality is worth noting. Therefore, in the vacuum evaporation coating machine, the vacuum degree selected for the coating chamber should generally be higher than 10-2Pa and lower than 10-5Pa.
       PVD evaporation coating machine is the most primitive PVD coating machine, the application is also the most extensive, the market share is also the highest, of course, with the continuous innovation and development of technology, new technologies continue to emerge, evaporation coating technology and equipment costs naturally account for the proportion Relatively low.