Precise shape nano-replication for an antireflective imaging lens using a mould with a thermal insulation layer

Abstract A nanostructure transfer process with precise shape accuracy was investigated for application to an imaging optical lens. For a nanostructure transfer process by injection moulding, the temperature of the mould must be higher than the melting point of the polymer. Therefore, precise shape accuracy is not a sufficient specification for an imaging optical lens. Using a mould with a thermal insulation layer for the nanostructure transfer process, the temperature of the mould was evaluated to be 20 °C lower than that of a conventional mould because the heat energy was accumulated by the thermal insulation layer. Notably, the precise shape accuracy was 6 times that of a conventional mould. When using a mould for developing an antireflection structure, an optical lens with a transferred nanostructure exhibited low antireflection of less than 0.5% and precise shape accuracy of 0.5 μm at a diameter of 5 mm. These specifications are sufficient for an optical imaging lens. We suggest that the mould is suitable for application to imaging lens.