Laser Direct Patterning of Indium Tin Oxide Layer for Plasma Display Panel Bus Electrode

Abstract

For the reduction of the fabrication cost and processing time of AC plasma display panels (PDPs), an indium tin oxide (ITO) layer was patterned as the bus electrode by direct writing with a Nd:YVO4 laser (λ=1064 nm). In comparison with the chemically wet-etched ITO patterns, laser-ablated ITO patterns showed the formation of shoulders at the edge of the ITO lines and a ripple-like structure of the etched bottom. For the Q-switched Nd:YVO4 laser and a galvanometric scanning system, 500 mm/s with 40 kHz repetition rate was suitable for the application to PDP manufacturing. When the laser ablation was applied in the fabrication of a PDP test panel, the laser-ablated ITO patterns showed a higher minimum sustaining voltage than that of chemically wet-etched ITO patterns, which is assumed to be a result of the shoulders at the edge and the ripple-like bottoms. It is necessary to conduct more investigations and analyses on the cause of the problems in laser-ablated ITO patterns to optimize laser patterning.