Secondary Patternable UV-Imprinted Reworkable Resin by Additional Photoirradiation

Abstract

The fabrication of secondary patterns on UV-imprinted resins was successfully achieved using a reworkable monomer. A methacrylate monomer, which has both an epoxy moiety and a thermally-cleavable tertiary ester moiety in a molecule, was employed as the reworkable monomer. UV imprinting of the reworkable monomer was carried out in the presence of a photoradical initiator by irradiation at 365 nm to fabricate micrometer-order patterns. Secondary patterning was carried out using the patterned resin containing a photoacid generator by irradiation at 254 nm through a photomask followed by baking at 110 ℃ for 1 min without development. The pattern formation is due to the acid-catalyzed decomposition of the tertiary ester linkages in the cured reworkable monomer measured by in-situ FT-IR and mass measurements.