Inkjet printing of microlens arrays on large, lithographic structured substrates

Micro-lens array manufacturing by using an inkjet printing technology allows for the manufacturing of large area arrays on lithographically structured substrates that contain oleophobic and oleophilic surface patterns. An inkjet printing process deposits the high performance, hybrid polymer ORMOCER on the oleophilic pattern. The material forms by means of surface tension and wetting boundaries a lens shape, while the inkjet printing process itself enables for a highly parallel manufacturing of many lenses at the same time. A typical geometrical deviation <2% of the radius of curvature for lenses with diameters of <1 mm, ROC's of ca. <2 mm and sag heights of <100 microns was achieved. Also a specific lithography processing regime was derived that combines wetting patterns with optical apertures to enable advanced illumination setups like multi-aperture projection.