Roll‐to‐roll coating of flexible glass

Flexible glass is a relatively new kind of substrate with a unique combination of properties that are, in different aspects, ideal for numerous applications. The material has aroused significant interest and has prompted activities in R&D communities dedicated to topics such as flexible electronics, flexible OLED and flexible PV. As a result, device demonstrators of considerable maturity have been created, some of which were even manufactured using a roll-to-roll (R2R) process. So far, these activities have not resulted in marketable final products that are produced in an industrial context. The key prerequisite for a widespread industrial adoption of R2R processing of flexible glass substrates is the availability of suitable and proven manufacturing equipment. The tools need to be able to handle and process this delicate material, taking into account its mechanical properties, which differ significantly from the typical flexible substrates such as paper, polymer film, or metal foil. This article discusses specific equipment aspects that need to be considered in the R2R handling of flexible glass, both in general and by taking the example of a roll-to-roll lab coating system. This tool has been designed specifically for handling flexible glass and will be available to the interested community from October 2016. Furthermore, it is shown how different processes such as R2R sputtering, evaporation, and flash lamp annealing can be used for potential flexible glass applications in flexible electronics, architecture, and energy conversion devices. Beyond that, related layer stacks deposited by vacuum coating will be discussed.