Characterization of micromachining processes during KrF excimer laser ablation of TiNi shape memory alloy thin sheets and films

We investigate excimer laser ablation of TiNi shape memory alloy thin sheets and films using an image projection system as a tool for micromachining and patterning. Characteristics of material removal by KrF excimer laser induced ablation at 248 nm and the dependence of material removal rates on laser parameters such as fluence and pulse frequency are explored. Fluences at the workpiece using a 10x projection lens were up to 2.5 J cm(-2) with pulse repetition rates up to 100 Hz. Conventional chrome-on-quartz masks were used for pattern transfer. Material removal mechanisms and rates of material removal were investigated for thin film samples and thin sheet samples having thicknesses of 3 and 150 mum respectively