2020-07-20 10:49:39 Popularity（1736）
Describe the steps in briefly as following:
Physical evaporation is to heat the substance to volatilize and then deposit its vapor on a predetermined substrate.
Because the evaporation source must be heated and volatilized and under condition of vacuum,
it is so called hot or vacuum evaporation.
It can be divided into 3 steps as below:
(1) The condensed matter is heated and volatilized into a vapor phase
(2) Steam moves in the air for a distance to the substrate
(3) Steam is cooled and condensed into film on the substrate