New technology for ultra-smooth polymer films

Smooth surfaces with low defect densities are of great importance for many application areas, from decoratively coated vehicle bodies to substrates for high-tech industries. Particularly in latter case, subsequent finishing steps can only exhibit their full potential if the surface quality of the substrate is also at a very high level. For example, films for encapsulation of electronic components need thin permeation barrier layers made by a vacuum coating process that prevent against penetration of oxygen and moisture. The deposition of active electronic layers, for example for OLEDs or touch screens, requires ultra-smooth surfaces to ensure reliably capabilities such as light emission and conductivity over large-areas.

Scientists at Fraunhofer FEP have now developed a new method for creating ultra-smooth surfaces – dubbed the smoothing-film approach. This innovative process does not require any special processing environment and could therefore also be used under standard factory conditions. With this new approach, a wet coating is applied to a flexible substrate. Afterwards, the wet coating is covered with a second film, the smoothing film. In the end the coating is dried via electron beam. In order to reduce the costs for the smoothing films, their reusability was examined. The scientists were able to show that even after reusing the smoothing film ten times, no increase in defect density or decrease of surface quality was observed.

Kontakt: Philipp Schulze, Fraunhofer Institute for Organic Electronics, Electron Beam and Plasma Technology FEP
marketing@fep.fraunhofer.de