First the tooling fixtures are placed into Carousels that are then moved into the vacuum chamber. A predetermined vacuum level is reached and current is sent to the evaporation source.
The source is a tungsten filament loaded with alloy (most commonly aluminum). The current heats the filament until the alloy evaporates, which forms a vapor cloud that bonds to the parts.
Thermal evaporation of alloys is a line-of-sight process so the tooling fixtures rotate in front of the evaporation sources to achieve a uniform coating. Upon completion of the metalizing process the chamber is returned to atmosphere and the tooling fixtures are unloaded.
Our proprietary EMI/RFI shielding process allows us to evaporate over 25 microns of aluminum, while the typical thickness of evaporated aluminum for light reflectors and chrome decorative coatings is approximately 1000 angstroms. In chamber pretreat and post treat processes aid in the adhesion of the coating.
We have seven automated vacuum chambers both thermal evaporation and magnetron sputtering which include four different sized chambers for a variety of applications and part sizes.