Abstract
Most of the photopatterning materials based on epoxy resins are utilizing photoacid generators (PAGs) which generate superacids as catalysts. They have been used for high aspect ratio photoresists in the fabrication of MEMS devices. However, there is a drawback that the acidic species from PAGs will induce metal corrosion. One of the approach to overcome this problem is the use of photobase generators (PBGs) because organic bases would induce no corrosion. Although there is a large number of investigation of PBGs in past time, only few articles have mentioned photoreactive materials relying on PBGs due to its low photosensitivity. We report here highly sensitive photopatterning materials comprising PBG and an epoxy resin bearing carboxylic acid groups. As a result, the photopatterning material showed higher photosensitivity when compared to conventional epoxy resin systems. We obtained high photosensitivity (up to 900 mJ/cm2), high resolution (10 μm line and space) patterning materials in thin films of 10 μm in thickness.
