Low-visibility processing of silver nanowire transparent conductive film by pulsed laser

Silver nanowire transparent conductive film is expected as a new material of transparent electrode, because it has superior flexibility and conductivity with transparency at visible wavelength. Recently, it has been used for thin film solar cells, flat panel displays and touch panels, since these electronic devices require the flexibility. It is essential to form insulation areas when using silver nanowire transparent conductive film in electronic circuit. Removal characteristics and mechanism of silver nanowire transparent conductive film by pulsed fiber laser were experimentally investigated in a view point of compatibility on insulation and low visibility. Color difference between processed and non-processed area becomes small with increasing laser fluence. The color difference is also small on processed area by shorter pulse duration at same laser fluence condition, but too short pulse duration causes excessive removal of silver nanowire from an over coated layer of resin. Silver nanowires are removed through an over coated layer, and difference of diffused light states between processed and non-processed area becomes remarkable as visible marks due to generation of many holes. A wide range of laser fluence to keep similar haze as diffused light states on processed area and non-processed areas can be obtained by longer pulse duration in nanosecond range. Wide processing window of laser fluence to keep diffused light state similar to that of non-processed area can be achieved at pulse duration more than 50 ns.