Vacuum evaporation coating (for short, Vacuum Evaporation) refers to the 

method of heating evaporation coating material (metal alloy or metal oxide) 

at high temperature to a certain temperature under certain vacuum conditions 

to vaporize its atoms or molecules from the surface to form steam flow and 

fly sputtering to the surface of glass substrate to condense to form solid film.

Because the main physical process of vacuum steam forging method is produced 

by heating evaporation material, it is also called hot evaporation method. 

As a key component of the evaporation device, most evaporation materials 

require evaporation at high temperatures 1000-2000 ℃. 

Vacuum evaporation can be divided into resistance method, electron beam evaporation method, 

high frequency induction method and laser evaporation method.