High-speed laser cutting of micro structures with submicron details

The demand on performance for displays and opto-electronics is ever increasing and the industry is looking for ways to produce large area microoptical films to help that cause. While conventional techniques are reaching their limits for large area structuring, earlier reports show that it is possible to structure a few m 2 polymer film with microoptical features (>20 μm) by direct laser ablation. By employing the same optics and hardware studies were carried out to find the minimal feature size possible without compromising the area that can be processed. Looking at the sub-resolution ablation behaviour of Polycarbonate enables us to modify the so-called Synchronised Image Scanning (SIS) mask design to control shape and form of 3D-features only a few times bigger than the resolution limit of the laser ablation mask projection system. Results of optical 10μm and 5μm features are shown and discussed. The findings show that it is realistic to direct laser cut well defined optical 3D-features into polymer film with an unprecedented feature-area-ratio in excess of 1:10 10 .