The high-frequency induction evaporation coating machine is also a type of evaporation vacuum coating machine. The crucible evaporation source used is different from the resistance evaporation coating machine and the electron beam evaporation coating. The high-frequency induction evaporation coating machine uses an induction coil to heat the film material, so it is named as the high-frequency induction evaporation coating machine. What are the differences and advantages between it and other evaporation coating machines?

The evaporation source used by the high-frequency induction evaporation coating machine is to place the graphite or ceramic crucible containing the evaporation material in the center of the water-cooled high-frequency helical coil, so that the evaporation material can generate strong eddy current loss and Hysteresis loss (for ferromagnets), which causes the evaporating material to heat up until it evaporates. The smaller the volume of the membrane, the higher the frequency of induction. In large-scale equipment for continuous vacuum aluminum deposition on steel strips, the high-frequency induction heating evaporation process has achieved satisfactory results.

Features of high frequency induction evaporation source:
       1) The evaporation rate is large, which can be about 10 times larger than that of the resistance evaporation source;
       2) The temperature of the evaporation source is uniform and stable, and it is not easy to produce splash phenomenon;
       3) When the evaporation material is metal, the evaporation material can generate heat;
       4) The evaporation source is charged at one time, no feeding mechanism is required, the temperature control is relatively easy, and the operation is relatively simple.
 
The disadvantages of high frequency induction evaporation vacuum coating machine are:
       1) Boron nitride crucibles with good thermal shock resistance and stable high temperature chemical properties must be used;
       2) The evaporation device must be shielded, and a more complicated and expensive high-frequency generator is required;
       3) The pressure near the coil has a fixed value. If it exceeds this fixed value, the high-frequency field will ionize the residual gas and increase the power consumption.