Analysis of the replication of high aspect ratio micro-structured surfaces by injection-compression molding

Mass production of micro-structured surfaces has gain great interest for optical and micro fluidic devices. The complete and uniform replication of a large surface is still challenging using state-of-the-art micro injection molding. Injection-compression molding might be a feasible and efficient way to overcome the intrinsic limitations of conventional technologies by uniformly distributing the cavity pressure, in particular for high aspect ratio micro features. However, injection-compression molding is characterized by more complex process control. In this work, the applicability of injection-compression molding for the replication of high aspect ratio micro features distributed over a large surface is studied. In order to achieve the required replication accuracy the study and the optimization of process parameters were carried out, considering the factors that affect the quality of the replication. Moreover, the thickness of the substrate was taken in consideration, as it directly influences the growth of the pressure inside the cavity. The obtained results show how the injection-compression molding process can be effective in increasing and leveling the replicated micro features height