Electron beam pvd coating machine evaporation source evaporation method, put the evaporation material into a water-cooled steel crucible, and directly use the electron beam to heat, so that the evaporation material is vaporized and evaporated and then condensed on the surface of the substrate to form a film, which is one of the vacuum evaporation coating technologies. An important heating method and development direction. Electron beam evaporation overcomes many shortcomings of general resistance heating evaporation, and is especially suitable for making melting point thin film materials and high-purity thin film materials. The vacuum evaporation technology that relies on electron beam bombardment evaporation can be divided into ring guns, straight guns, e-type guns and hollow cathode electron guns according to the different forms of electron beam evaporation sources.

        The ring-shaped gun emits an electron beam from a ring-shaped cathode, which is focused and deflected and hits the crucible to evaporate the metal material. Its structure is relatively simple, but its power and efficiency are not high, and it is basically only a laboratory equipment, which is no longer used in production-type devices.
        The straight gun is an axisymmetric linear acceleration gun. Electrons are emitted from the cathode of the filament and gathered into thin beams. After being accelerated by the anode, they are hit in the crucible to melt and evaporate the coating material. The power of the straight gun ranges from hundreds of watts to hundreds of kilowatts, some can be used for vacuum evaporation, and some can be used for vacuum smelting. The disadvantage of the straight gun is that the vapor-deposited material will contaminate the structure of the gun body, which will bring difficulties to the stability of operation. At the same time, the sodium ions escaping from the emitting filament will also cause contamination of the film layer. A deflecting magnetic field is set at the exit of the electron beam, and an independent air extraction system is made at the filament part to make an improved form of a straight gun, which not only completely dries the filament from contamination of the membrane, but also helps to improve the life of the gun. 
       The e-type electron gun, that is, the electron gun deflected at 270 degrees Celsius, overcomes the shortcomings of the straight gun, and is one of the more electron beam evaporation sources currently used. The e-type electron gun can generate a lot of power density, can melt metals with high melting point, and generate high energy of evaporated particles, so that the film layer and the substrate are firmly combined, and the quality of the film is better. The disadvantage is that the electron gun requires a high degree of vacuum and needs to use negative high pressure, which results in a complex structure of the equipment, poor safety, difficult maintenance, and high cost.
       The hollow cathode electron gun of electron beam vacuum coating machine uses the plasma electron beam generated by the hollow cathode discharge of low voltage and high current as the heating source. The hollow cathode electron gun uses a hollow tantalum tube as the cathode, the crucible as the anode, and an auxiliary anode is installed near the tantalum tube. When the hollow cathode electron gun is used for vapor deposition, the generated vaporized ion energy is high, and the ionization rate is also high, so the film formation quality is good. The hollow cathode electron gun has lower requirements on the vacuum degree of the vacuum chamber than the e-type electron gun, and uses low voltage to work. Relatively speaking, the equipment is simpler and safer, and the cost is also low. At present, e-type electron guns and hollow cathode electron guns have been successfully used in evaporation and ion plating equipment in our country. The power of the gun can reach tens of thousands of kilowatts, and various films have been plated for machinery, electronics and other industries.
       The advantages of the evaporation source of the electron beam pvd coating machine are:
        1) The beam density of electron beam bombardment heat source is high, which can obtain far greater energy density than that of resistance heating source. It can evaporate materials up to 3000 degrees or more, and can have a high evaporation rate;
        2) Since the material to be evaporated is placed in a water-cooled crucible, the evaporation of the container material and the reaction between the container material and the evaporation material can be avoided, which is extremely important to improve the purity of the coating;
        3) Heat can be directly added to the surface of the vapor deposition material, so the thermal efficiency is high, and the loss of heat conduction and heat radiation is small.