Introduction to Vacuum Vapour Plating Process

Vacuum vapour deposition is a method of heating a metal under high vacuum conditions, causing it to melt, evaporate and then form a metal film on the surface of the plastic after cooling. The metals commonly used are low melting point metals such as aluminium.

The method of heating the metal: either by using heat generated by electrical resistance or by using an electron beam.

When vapour deposition is applied to plastics, the deposition time must be adjusted to ensure that the heat given off by the cooling of the metal does not distort the resin. In addition, metals or alloys with too high a melting or boiling point are not suitable for vapour plating.

The metal to be plated and the plated plastic products in the vacuum chamber, using certain methods to heat the material to be plated, so that the metal evaporates or sublimates, the metal vapour meets the cold plastic products surface cohesion into a metal film.

Under vacuum conditions can reduce the atoms of evaporated materials, molecules in the process of flying to the plastic products and other molecular collision, reduce the active molecules in the gas and evaporation source materials between the chemical reaction (such as oxidation, etc.), so as to provide the density of the film, purity, deposition rate and adhesion. Usually, vacuum evaporation requires a pressure equal to or lower than 10-2 Pa in the film-forming chamber, or lower ( 10-5 Pa) for applications where the evaporation source and the product to be plated and the quality of the film are very high.

Plating thickness 0.04-0.1um is too thin, low reflectivity; too thick, poor adhesion, easy to fall off. At a thickness of 0.04, the reflectivity is 90%.