Coating methods and classification

Film formation under vacuum conditions has many advantages: it can reduce the collision of atoms and molecules of the evaporated material with molecules in the process of flying to the substrate, reduce the chemical reaction (such as oxidation, etc.) between the active molecules in the gas and the evaporation source material, and Reduce the amount of gas molecules entering the film to become magazines during the film formation process, thereby improving the density, purity, deposition rate and adhesion of the film layer to the substrate. Usually, vacuum evaporation requires that the film forming chamber is equal to or lower than 10-2P. For occasions where the distance between the evaporation source and the substrate is long and the film quality is required to be high, the pressure is required to be lower.

Application Products of Evaporation Coating Equipment

Mainly divided into several categories:

Evaporative coating and sputtering coating

Evaporation coating: It evaporates a substance by heating to deposit it on a solid surface, which is called evaporation coating. This method was first proposed by M. Faraday in 1857, and it has become one of the commonly used coating techniques in modern times.

Evaporated substances such as metals, compounds, etc. are placed in the crucible or hung on the hot wire as the evaporation source, and the workpiece to be plated, such as metal, ceramic, plastic and other substrates, is placed in front of the crucible. After the system is pumped to a high vacuum, the crucible is heated to evaporate its contents. The atoms or molecules of the evaporated substance are deposited on the surface of the substrate by condensation. The film thickness can be hundreds of angstroms or microns. The film thickness is determined by the evaporation rate and time of the evaporation source, and is related to the distance between the source and the substrate. For large-area coating, a rotating substrate or multiple evaporation sources are often used to ensure the uniformity of the coating layer thickness. The distance from the evaporation source to the substrate should be less than the mean free path of the vapor molecules in the residual gas, so as to avoid chemical interactions between the molecules and the residual gas molecules due to collisions. The average kinetic energy of vapor molecules is about 0.1~0.2 electron volts.

Evaporation coating method can also be applied to many products, such as: mobile phone plastic structural parts, smart home, digital products, cosmetic packaging, handicrafts, toys, wine packaging and electronic components and other products.

The application products of sputtering coating include: electronic product hardware, high-end clocks, high-end jewelry, brand leather hardware and other products.