Development Of Multifunctional Vacuum Coating Control System With High Ionization Rate

High ionization rate is critical in ion deposition area. It cannot only improvethin film properties, such as density and cohesion remarkably, but also hasplayed significant role in depositing complex shaped work piece, lowingprocessing temperature and directing materials to different areas. Modulatedpulsed power (MPP) and pulse Enhanced Electron Emission (P3e) both have highionization rate. A vacuum coating control system is developed, combining powersources related to these techniques with other vacuum equipment.To automate the system including MPP and P3e power source, data mμst beshared among different equipment in the first place. Siemens S2-700PLC isadopted as the central communicating module, programmed by SIMATIC LAD torealize the one-master-multi-slave communication method; as for analog quantityunsupported by digital communication, RS485converting circuits weredeveloped, and on-off signals are controlled by YC1008module; Computersoftware containing Labview2013and OPC Servers are utilized as HMI. Inaddition to communication, automation programs run to achieve setting anddetecting functions.The main parameters of self-developed MPP power source include5kWaverage power,400kW peak pulse power,17-400Hz overall frequency,continuoμsly adjμstable frequency of inner pulse, and modulated pull-down waveto achieve required oscillation amplitude. Under water load tests, complex waveforms through various electric parameter settings; Cr target dischargecharacteristics were investigated in vacuum, and effect of wave oscillation onMPP was also discussed; Cr target discharge spectra with MPP, DCMS andHPPMS were measured and spectral lines and glow amplitude were analyzed,and the results shows that the ionization rate is higher with MPP power sourcethan that with DCMS.The main parameters of self-developed P3e power source are：22.7~1.17kHzfrequency，55μs~620μs pulse width，0~400A pulse current，0~60A averagecurrent. Under water load tests, power source capacity were verified by settingwide-range parameters; Ti target discharge was investigated in vacuum; theimpact of pressure and electric parameters was discussed via measuring currentsof work piece using P3e power source and also dc power source acts with thesane average current as control group.