Product Code: ICAL07_M404

Surface Structuring of Polyimide by Pulsed Laser Ablation
Authors:
Rui Vilar, Instituto Superior Tnico; Lisboa Portugal
Victor Oliveira, Instituto Superior T�Cnico; Lisboa PA Portugal
Presented at ICALEO 2007

Laser ablation has been extensively studied in polymers because of their considerable utility in diverse fields such as medicine, microelectronics, photonics, etc. Among the many aspects of laser ablation of polymers, several authors have reported the formation and growth of conical structures during laser processing with UV laser radiation. In the present paper, polyimide surfaces were processed with pulsed KrF laser radiation at fluences near the ablation threshold of the polymer. The morphology of the processed surfaces is studied by scanning electron microscopy. The formation of conical structures is observed for fluences lower than 0.5 J/cm². Moreover, the areal density of cones increases with increasing number of pulses and decreases with increasing laser fluence. The mechanisms of cone formation previously proposed in literature are discussed. Finally, the wettability of the laser processed surfaces is measured by the contact angle method and possible application of these features discussed.