Cost-effective PVD coatings in batch systems

The high investment and operating costs for PVD coating systems hamper the broader application of this high technology, especially in smaller and medi um sized enterprises. The reduction of these costs to an amount where high quality coatings are economically attractive by their continuous as well as in a two or even a one shift production can only be achieved by the optimi zed working together of all components of a coating system. The enlargement of the volume of the vacuum chamber is limited by the avail ability of huge vacuum pumps at reasonable prices but, nevertheless, the nu mber of charges per day can be increased by suitable techniques. Cryopumps, for example, can be applied very successfully, especially with a view to t heir high pumping speed for water. By optimizing the pumping speed in the c hamber for different gases, the consumption of sputter or reactive gases an d therefore the amount of pumped gas can also be lowered leading to longer times between regenerations and, eventually to a minimum down time. By combining different coating techniques, also in modified forms, the adva ntages of them can be used in one process in order to achieve cost effectiv e high quality coatings. For such hybrid processes, the precise tuning of t he components working together and the control of the whole process with th e needed reliability is absolutely necessary and to achieve with a PLC and appropriate bus systems. Finally, the coating technology used is very important. The production of l ayer systems for special coating tasks consisting of many layers requires n ot only high reliability of the working together of all components but also a suitable management of the techniques for the control. This article summarizes the most important problems of cost effective PVD c oatings in batch systems and shows possible solutions. (C) 1999 Elsevier Sc ience S.A. All rights reserved.