Although there are many types of ion sources, the purpose is nothing more than online cleaning, improving the energy distribution on the surface of the PVD vacuum coating, and modulating and increasing the energy of the reaction gas. The ion source can greatly improve the bonding strength of the membrane and the substrate, and at the same time can also improve the hardness, wear resistance and corrosion resistance of the membrane itself. If it is the wear-resistant layer of electroplating tools, the thickness is generally large, and the film thickness uniformity is not high. An ion source with a larger ion current and a higher energy level can be used, such as a Hall ion source or an anode layer ion source.
　　 The anode ion source is similar to the Hall ion source. A strong magnetic field is applied in a ring-shaped (rectangular or circular) narrow gap, and the working gas is ionized and emitted to the workpiece under the action of the anode. The anode ion source can be made very long, especially suitable for plating large workpieces, such as architectural glass. The ion current of the anode ion source is also relatively large. But the ion current diverges, and the energy level distribution is too wide. Generally suitable for large workpieces, glass, wear and decorative workpieces. However, there are not many applications in advanced optical coatings.
　　 Kaufman ion source is the ion source used earlier. Belongs to grid ion source. First, the cathode generates plasma in the ion source cavity, and then the ions are extracted from the plasma cavity through two or three anode grids. The ion source has strong directivity and concentrated ion energy bandwidth, and can be widely used in vacuum coating. The disadvantage is that the cathode (usually a tungsten wire) burns out quickly in the reaction gas, and the ion flux is limited, which may make users who need a large ion flux uncomfortable.
　　Hall ion source is a kind of anode, which performs plasma treatment on the process gas under the action of a strong axial magnetic field. This strong imbalance of the axial magnetic field separates the gas ions and forms an ion beam. Because the axial magnetic field is too strong, the ion beam of the Hall ion source needs to be supplemented with electrons to neutralize the ion current.