Fabrication and performance of an ultrafine silver grid film applied to flexible touch sensor

The fabrication and performance of an ultrafine silver (Ag) grid film applied to flexible touch sensor as the transparent conductive electrode is reported. The ultrafine Ag grid film was fabricated based on the laser direct writing, electroforming, nano-imprint lithography. In the manufacturing process, firstly, the Nickel (Ni) mold used as the master mold was obtained by laser direct writing and electroforming technologies. Secondly, the micro-grooves were transferred from the Ni mold onto the surface of UV glue coated on the polyethylene terephthalate film through nano-imprinting technology. Lastly, the ultrafine Ag grid was generated through nano-imprint lithography with Ag paste filled into the micro-grooves on the UV glue. The result indicated that the ultrafine Ag grid film with size (L) 640 mm x (W) 520 mm had a uniform line width of 1.01 [inn and showed excellent optoelectronic and mechanical properties, such as optical transmittance 90.00%, Haze 1.49%, sheet resistance 5.4 Omega/square, the variation ratio of the sheet resistance within 3% after 8000 bending cycles, and the almost negligible morphology change after the adhesion cross-cut test. Furthermore, the functional test was performed on a flexible touch sensor applying the ultrafine Ag grid film.