Photocuring behaviors of epoxy resins using deep-uv leds

Abstract

We investigated the formulations of epoxy resins which were used with deep-UV LED lamps. The mixtures of epoxy monomers and photoacid generators (PAGs) were placed on a silicon wafer to form films. The films were irradiated by deep-UV lamps which emit 265, 285 or 300-nm light. The effects of the PAGs, irradiation wavelengths, and film thicknesses on the reactivity were investigated by FT-IR spectroscopy and a photo-DSC study. We found that a sulfonium salt having a thiophenyl moiety was the most effective PAG. We also found that less than 100-m thick films were effectively cured by irradiation from the deep-UV LEDs.