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 o C 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.

Visible-Light Sensitive Reworkable Resins: A Rheological Study

“…On the other hand, the G'max/G'min value of MBDMA was not obtained. After decomposition, the cured and irradiated DHDMA and MOBH generated low-molecularweight fragments, such as 2,5-dimethyl-2,4hexadiene [8] and limonene [16] (Schemes 1 and 3). On the other hand, the cured and irradiated MBDMA may form poly(methacrylic acid) and poly(3-methyl-3-butenyl methacrylate) (Scheme 2), and no low-molecular-weight fragments may be generated.…”

“…On the other hand, the crosslinked poly(MOBH) may form networks after UV irradiation in the presence of the photoacid generator (Scheme 3). After subsequent heating, poly(methacrylic acid), polyepoxide from poly(MOBH), and limonene [16] may be formed (Scheme 3). The effect of the chemical structures or the reaction conditions on the rheological properties of the cured or photo-degraded resins is also discussed.…”