Manufacturing process for the micro fluidic device can include such sequential steps as master fabrication, electroforming, and injection molding. The laser ablation using masks has been applied to the fabrication of channels in micro fluidic devices. In this study, manufacturing of polymer master and mold insert for micro injection molding was investigated. Ablation of PET (polyethylene terephthalate) by the excimer laser radiation could be used successfully to make three dimensional master for nickel mold insert. The mechanism for ablative decomposition of PET with KrF excimer laser (λ: 248 ㎚, pulse duration: 5 ㎱) was explained by photochemical process, while ablation mechanism of PMMA (polymethyl methacrylate) is dominated by photothermal process, the reaction between PC (polycarbonate) and KrF excimer laser beam generate too much surface debris. Thus, PET was adopted in polymer master for nickel mold insert. Nickel electro forming using laser ablated PET master was preferable for replication method. Finally, it was shown that excimer laser ablation can substitute for X-ray lithography of LIGA process in micro structuring.
