Laser direct etching for a PDP cell using Nd:YAG laser

초록

A photoresist films on Si and commercial glass and the paste dried and hardened for forming barrier rib of PDP (Plasma Display Panel) were directly etched with Ar+ laser and Nd:YAG laser beam. Exposing the photoresist to a fourth harmonic Nd:YAG laser beam (λ=266㎚) to produce electrodes on the transparent conductive material, the etching threshold laser fluence was 25 J/㎠ and the damage of substrate was appeared over the laser fluence of 40 J/㎠. The reaction mechanism of the photoresist by the UV laser beam, compared to that by Ar+ laser (λ=514㎚), is photon-assisted ablation. A barrier rib is composed of mixtures that were made from organic gel, glass powder and ceramic powder. Using a second harmonic Nd:YAG laser (l=532 ㎚) the threshold laser fluence was 65 mJ/㎠ for the barrier rib sample softened at 120 ℃. The thickness of 130 ㎛ of the sample on the glass was clearly removed without any damage on the glass substrate by laser fluence of 19.5 J/㎠. The barrier rib samples on hot plate were etched by Nd:YAG laser (532 ㎚) with increasing a temperature of the sample. The etch rate at 200 ℃ was 4 times of that at room temperature. Indium tin oxide thin films (ITO) on lime glass were directly etched using the second and fourth harmonic Nd:YAG laser beam.