Double-sided electrode and pattern process thereof

A patterning process for forming a double-sided electrode structure includes: providing a substrate having two opposite surfaces, wherein a first photo-sensitive layer and a second photo-sensitive layer are respectively formed on the opposite surfaces; forming a first metal nanowire layer on the first photo-sensitive layer and a second metal nanowire layer on the second photo-sensitive layer; and performing a double-sided lithography process. The lithography process includes: performing an exposure process to define a removing area and a remaining area on both of the first and the second photo-sensitive layers; and removing the first and second photo-sensitive layers and the first and second metal nanowire layers in the defined removing areas by a developer solution, thereby patterning the first and second metal nanowire layers.