I am sending you offers to the question "Getting quality vacuum coating". For the formation of high-quality coatings, which are especially necessary for expensive and important product, it is advisable to take into account the following conditions:
- Surface preparation.
- Composition residual medium in a vacuum chamber.
- Nucleation and formation of the coating.
1. Preparation surface
Surface preparation is divided into two phases in atmospheric conditions and surface cleaning in the vacuum chamber of the cathode material ions and ions of process gases. With regard to cleaning in atmospheric conditions, it is known for a wide range of equipment, washing, drying in the different working environments and solutions. The most precise method is cleaning with gas ions further shift (if the material of the substrate and the cathode) the cleaning ions of the cathode material. It should be noted that the ion gas source must be controlled by an anode voltage of 100 volts and higher. In addition, the ion source must provide accompanying regime ion treatment (assisting) at pressures of 10-3 - 10-2 mm Hg., And be sustained in the event of microarcs that arise in the process of cleaning. For such environments is proposed ion source with a pulsed power supply capacity of 2-2.5 kW.
2. Composition residual protection
Residual medium in the vacuum chamber is mainly determined by three components, the flow of the process gas stream gas and vapors emissions from the cathode, tooling, vacuum chamber walls and back flow of vapors from the working fluids of vacuum pumps. Reverse flow of vapor diffusion pump enough significant due to the fact that the pump is running in a non-stationary mode (pressures pump = (5x10-4 - 5x10-5) mm Hg, and the mode of application for pressures 10-3 mm Hg) and this pressure range the greatest observed vapor delivery of working oil in the vacuum pump chamber. For the technology is important to have information on the composition of the residual medium in the vacuum chamber and the ability to control the flow of process gas for the stoichiometric composition of the coatings. For this purpose, the analysis system is proposed to use the residual medium and controlling the flow of process gas from the spectra of nitrogen, titanium, oxygen, carbon, and other gases and vapors.
3. Nucleation and growth of coatings
The quality of the coating significantly reduces the presence of a drop phase, which is a consequence of the plasma source. Droplet phase can be reduced significantly through the use of pulsed arc power supply sources and plasma separators. Besides, to stabilize the temperature conditions necessary to ensure operation of the ion source in a mode of coating deposition. Thus for a set of high-quality coatings on NNV includes:
- Apply the ion source gas with impulse power supply.
- Use arc plasma sources with separation and pulse power supply.
- Put in the vacuum system of the automatic flow control process gas from the spectrum of the plasma.