In daily life, electron beam evaporation coating machine coating technology is most commonly used in electronic products, such as screens, mobile phone cases, lenses, glass, etc. It has high melting point, fast efficiency, good uniformity of the film layer, and can be coated with various film materials, etc. Advantages, so it is mostly used in electronic products. Below, the editor of Huicheng Vacuum will introduce the coating principle of the electron beam evaporation coating machine in detail, hoping to help you:

Putting the evaporation material into a water-cooled steel crucible and directly heating it with an electron beam, the evaporation material vaporizes and condenses on the surface of the substrate to form a film. This is an important heating method and development direction in vacuum evaporation coating technology. Electron beam evaporation overcomes many shortcomings of general resistance heating evaporation and is particularly suitable for producing melting point thin film materials and high-purity thin film materials.
Vacuum evaporation technology relies on electron beam bombardment evaporation. According to the different forms of electron beam evaporation sources, it can be divided into ring guns, straight guns, e-type guns and hollow cathode electron guns.
The ring gun emits an electron beam from a ring-shaped cathode, which is focused and deflected and then hits the crucible to evaporate the metal material. Its structure is relatively simple, but its power and efficiency are not high. It is basically only a laboratory equipment and is no longer used in production equipment.
The straight gun is an axially symmetrical linear accelerating 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 direct guns 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 evaporated material will contaminate the gun structure and bring difficulties to the stability of the operation. At the same time, the sodium ions escaping from the emitting filament will also cause contamination of the film layer. Recently, a West German company studied it in A deflection magnetic field is set up at the exit of the electron beam, and an independent air extraction system is made at the filament part to create an improved form of a straight gun. This not only completely eliminates the contamination of the film by the filament, but also helps to increase the life of the gun. .
The e-type electron gun, which is an electron gun deflected at 270 degrees Celsius, overcomes the shortcomings of a straight gun and is one of the most commonly used electron beam evaporation sources. The e-type electron gun can generate a lot of power density and can melt metals with high melting points. The evaporated particles produced have high energy, which makes the film layer and the substrate firmly bonded, and the film forming quality is good. The disadvantage is that the electron gun requires a high degree of vacuum and the use of negative high voltage, which results in a complex structure of the equipment, poor safety, difficulty in maintenance, and high cost.
The hollow cathode electron gun uses the plasma electron beam generated by the discharge of a low-voltage, high-current hollow cathode as a heating source. The hollow cathode electron gun uses a hollow tantalum tube as the cathode, the crucible as the anode, and an auxiliary anode installed near the tantalum tube. When using a hollow cathode electron gun for evaporation, the evaporated ions produced have high energy and high ionization rate, so the film formation quality is good. The hollow cathode electron gun has lower vacuum requirements for the vacuum chamber than the e-type electron gun, and it works at low voltage. Relatively speaking, the equipment is simpler and safer, and the cost is lower. At present, e-type electron guns and hollow cathode electron guns have been successfully used in evaporation and ion plating equipment in my country. The power of the gun can reach tens of thousands of kilowatts, and it has plated various thin films for the machinery, electronics and other industries.
 
Electron beam evaporation coating machine coating advantages:
1) The electron beam bombards the heat source with a high beam current density and can obtain a far greater energy density than the resistance heating source. It can evaporate materials up to 3000 degrees and has a high evaporation rate;
2) Since the evaporated material 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 for improving the purity of the coating;
3) Heat can be directly added to the surface of the evaporation material, so the thermal efficiency is high and the loss of heat conduction and heat radiation is small.