Vacuum coating of large areas

The major problems of today, e.g. the shortages of certain raw materials, the increase in energy costs and growing environmental pollution, have led to fresh applications of physical vapour deposition (PVD) techniques. In some cases large quantities of coated materials are needed to satisfy existing demands. Consequently, a relatively high areal throughput per unit time must be achieved in the corresponding coating plants. Such applications include the production of coated flat glass panes for the building and automotive industries and for mirrors, the coating of paper and plastic films for capacitors and for heat-reflecting, packaging and decorative products as well as the vacuum coating of strip steel to ensure adequate corrosion protection of large areas. For these applications of PVD techniques, it is vital to achieve under industrial conditions the best uniformity of film thickness and maximum coating width, transfer speed and deposition rate. We discuss the principal tasks and problems of coating processes and plant instrumentation for the three main fields of use. Finally, an assessment is given of the state of the art and of the prospective trend of developments.