Advanced packaging materials for optical applications: bridging the gap between nm-size structures and large-area panel processing

During the last two decades, nano-materials have been intensively investigated due to their wide range of properties, resulting in a variety of applications. In order to serve as advanced packaging material, from an industrial point of view emphasis has also to be on cost reduction either for the materials, the processes, or for both. Materials are searched for which enable processing and integration from a nm up to a cm scale. A particular class of low-cost nanoscale materials fulfilling this requirement are inorganic-organic hybrid polymers (ORMOCER®)1 which are synthesized by catalytically controlled hydrolysis/polycondensation reactions, resulting in storage-stable resins. Due to the variety of chemical and physical parameters, the material and processing properties which directly influence the resulting structure and thus the physical properties, can be varied over wide ranges. Upon synthesis, functional organic groups are introduced into the material which allows one to photochemically pattern the resins. The materials are capable to be patterned on a nm up to a cm scale, employing a variety of different micro- and nanopatterning methods such as, UV lithography, UV replication/lithography, laser-direct writing, or two-photon polymerization, in order to generate micro- and nano-optical components. While for most of the techniques the patterning has to be repeated several times in order to achieve multi-functional layers, the latter method allows one to directly write arbitrary 3D structures into the hybrid polymer material. The combination of chemically designed low-cost materials with tunable material parameters such as low optical absorption, tunable refractive index, good processibility, and high chemical, thermal and mechanical stability, is very attractive for (integrated) optical applications. Examples for application of the materials for microoptics as well as for optical back-planes generated by large-area processing will be given.