During the operation of a vacuum coating machine, various factors are required, such as environmental requirements for vacuum coating and requirements for the substrate and coating. Only by meeting each requirement can the vacuum coating machine improve and ensure the yield of high-quality coated substrates. So, what specific conditions and factors are needed for the operation of a vacuum coating machine? Below, Huicheng Vacuum will provide a detailed introduction to the environment, coating, and coating process of vacuum coating machines, hoping to help everyone:
A vacuum coating machine works by using a magnetic field in a vacuum state to make electrons bombard argon gas, forming argon ions, which then bombard the target material. The target material ions deposit on the surface of the workpiece to form a coating. For headlight coating machine manufacturers, factors related to the uniformity of the coating thickness include the vacuum state, magnetic field, and argon gas. The vacuum state requires a pumping system to control it. Each pumping port should operate simultaneously with consistent force to control the uniformity of the vacuum. If the vacuum is not uniform, the pressure inside the vacuum chamber will be uneven, which affects the movement of ions.
(1) Environmental requirements for vacuum coating
Proper cleaning of the substrate (base) surface before vacuum coating is very important. Before entering the coating chamber, the substrate should undergo careful pre-coating cleaning to remove oil, dirt, and moisture.
Surface contamination comes from dust, lubricating oil, grease, polishing paste, sweat, etc., that may adhere to parts during processing, transport, or packaging; oxide films formed on the surface in humid air; and gases absorbed and adsorbed on the surface. Most of these contaminants can be removed using degreasing or chemical cleaning methods.
For cleaned surfaces, they should not be stored in an open atmosphere but in closed containers or cleaning cabinets to reduce dust contamination. Storing glass substrates in freshly oxidized aluminum containers can minimize the adsorption of hydrocarbon vapors, as these containers preferentially absorb hydrocarbons. Highly unstable surfaces sensitive to water vapor should generally be stored in a vacuum drying box.
Removing dust from the coating chamber, creating a highly clean workspace, and maintaining a high level of cleanliness are basic environmental requirements for the coating process. In areas with high humidity, in addition to carefully cleaning the substrate and all parts of the vacuum chamber before coating, baking to remove gas is also necessary. It is important to prevent oil from entering the vacuum chamber, watch out for backstreaming from diffusion pumps, and take oil-blocking measures for high-power diffusion pumps.
(2) Basic principles of coating and vacuum deposition
A. Raw materials and basic principles:
Raw materials include resins, polymers, PTFE, silicone, acrylics, silicates, etc., with different additives, formulas, and proportions. For example, the type and amount of emulsifier added affect the emulsion state—water-based, milky, or paste-like states can all be achieved. These substances, after emulsification and demulsification, partially penetrate or form a thin film.
B. Their characteristics and differences:
Coating: good penetration (depending on the particle size of raw materials), smoother surface, suitable for painted surfaces with more “capillary pores,” roughness, re-sprayed paint, or hard paint surfaces, especially for European and American car paints that require enhanced gloss.
Coating: Coating products add film-forming agents and curing agents, and vacuum coating manufacturers make them form a film instantly, which changes their properties.
The coating environment and the coating itself in a vacuum coater are really important factors. If the vacuum level isn’t high enough, the conditions for coating just aren’t there, and at the same time, the yield will be far from ideal.
Your message must be between 20-3,000 characters!
