When the vacuum coating machine is running, it needs power supply to power its target and substrate. For example, the magnetron target used in the vacuum coating equipment for magnetron sputtering needs to be equipped with a magnetron power supply, which is imported and domestic. The power supply used in the multi arc ion vacuum coating machine becomes the arc power supply, which is also called the cathode power supply and bias power supply.

The arc power supply is the realization of target evaporation and ionization in the arc ion coating. It must rely on the arc power supply to provide energy. In the actual coating process, the power supply must be able to automatically detect the arc extinguishing phenomenon and automatically start the arc to ensure the continuity and uniformity of the film during the coating process; In addition, the arc stabilizing performance of the arc power supply, especially the minimum arc stabilizing current, has a great influence on the consistency, efficiency and smoothness of the film. A multi arc ion plating machine can distribute a few arc power supplies, more than a dozen, or even dozens. Stable and reliable operation is critical to the performance of the whole equipment. The arc power supply has developed from the traditional power supply to the current high-frequency inverter through the use of silicon controlled technology. Compared with the arc power produced by traditional electromagnetic and silicon controlled technology, the high-frequency inverter arc power supply has the following characteristics:
1. The size is reduced, which is only a fraction of the old power supply; The weight of the corresponding power supply is only a fraction to a tenth of that of the traditional power supply.
2. The efficiency of the power supply is obviously improved, about 20%~30% higher than that of the old power supply.
3. It is easy to operate, with high current regulation accuracy and good current stability, which is conducive to accurate control of film thickness and guarantee the repeatability of film thickness.
4. The high-frequency inverter arc power supply has smaller ripple, and its response speed is much higher than the old power supply. Under the same arc source and working conditions, the use of high-frequency inverter arc power supply is conducive to improving the stability of the arc and reducing the number of arc extinguishing.
Magnetron sputtering power supply: In terms of output waveform, with the development of magnetron sputtering technology itself, it has experienced DC, monopolar pulse, symmetric bipolar pulse (medium frequency magnetron sputtering power supply) and bipolar pulse (asymmetric medium frequency magnetron sputtering power supply). At present, the new magnetron sputtering power supply is basically made of high-frequency inverter switching power supply technology, and the medium frequency magnetron sputtering power supply has become the preferred power supply for new magnetron sputtering machine. In order to control the film thickness accurately, the magnetron sputtering power supply must work stably and have a good constant characteristic. At present, constant current mode is mainly used, but constant power mode is also used, and constant voltage mode is rarely used. In addition, a remarkable advantage of magnetron sputtering coating technology is that the film is dense and smooth. To realize this advantage, it is necessary to strictly limit the number of firing times and the energy of each firing on the target surface during the magnetron sputtering process, and minimize the number of macro target particles caused at the moment of firing. They will reduce the density and finish of the film layer, and in serious cases, the film will fall off.
Bias power supply: used in multi arc ion and magnetron sputtering coating technology. Because the ionization rate of magnetron sputtering is far lower than that of multi arc ion plating, the power required for bias power supply is smaller. At present, many devices are equipped with both magnetron sputtering targets and multi arc targets. The power of bias power supply should be selected according to the requirements of multiple working devices. In the early days, the bias voltage was mainly DC bias power supply using silicon controlled technology. Now, most of them are unipolar, DC superimposed pulse and bipolar pulse bias power supply using high-frequency inverter technology. Bias power supply is mainly used to apply bias voltage on the plated workpiece during glow cleaning, ion bombardment and film deposition in the process of multi arc ion and magnetron sputtering coating. It generates glow during glow cleaning; In ion bombardment, it is used to accelerate ions, increase the energy of ions bombarding the workpiece surface, achieve the purpose of sputtering cleaning effect and improve film adhesion. During film deposition, it is also used to increase ion energy, promote and improve film growth, and also improve film substrate adhesion. The following are several common waveform bias power supplies:
Main features of unipolar pulse bias power supply:
1. High frequency unipolar pulse bias is applied to the workpiece. Compared with DC bias, due to the existence of voltage interruption gap, it can effectively reduce the number of strikes and protect the workpiece surface.
2. During the pulse gap, the charge accumulated on the workpiece surface can be neutralized, thus reducing the spark caused by the accumulation of surface charge.
3. The quick turn off capability in the high-frequency inverter technology can effectively reduce the energy released each time of ignition, and can significantly reduce the degree of large damage to the workpiece surface even when ignition occurs.
4. The ion energy deposited on the workpiece surface during the pulse gap is very low.
5. The film forming speed and quality can be improved and controlled by adjusting the frequency and duty cycle.
The above are just a few common power supplies for vacuum coating machine. The power supply needs to be selected according to its process requirements and cost performance ratio. When purchasing different vacuum coating machine, manufacturers will choose different appropriate power supplies.