New Inks for the Direct Drop-on-Demand Fabrication of Polymer Lenses
The advent of cell phone cameras extensively pushed market needs for micro lenses and supported developments like the Wafer-Level-Camera Technology . Different optical applications and patterning methods for micro lenses require different sets of materials. Micro ink-jet printing (micro IJP) is an alternative and innovative direct patterning method for the manufacture of micro optical systems. We demonstrate the development of two material compositions – an epoxy resin and a sol–gel based material – which are used as inks with physical parameters adapted to the patterning technique so that stable and reproducible drops in both continuous and drop-on-demand (DoD) mode can be generated. The manufacturing of micro lenses, the lens characterization, their geometry and their optical properties are presented.