One way for pressure control of sputtering coating system

With the analysis on the performance of the common sputter ing coating system and the problems in the coating procedure,We obtained that:during sputtering coating,because the working pressure is at the constant dischargement area(jet overload area on first stage)of diffusion pump.when diffusion pump works in the enviroment,the backflow is very serious,and instability of jet cause the pressure uncontrolled.We raise an improved design project which used the diffusion pump series as the sputter coating pumping system,The theory anlysis shows if this project is adopted and the pressure of the inlet of the diffusion pump is maintained in the constant pumping speed area,the backflow will decrease and the working pressure of the coating room will be easily stabilized.