Multi-layered Ag film pattern printed by spatially modulated pulsed laser beam

Ag film solution-deposited on the glass source substrate was selectively transferred onto a receiver substrate by a spatially modulated pulsed ultraviolet laser beam. After printing a line pattern, an additional layer was orthogonally printed over the first layer. It was found that the thickness of the first layer is a crucial factor affecting the mechanical stability of the overall pattern. When the first layer was thicker than 0.7 μm, the second layer was cracked at the junction edges regardless of its thickness. This is attributed to the vertical elongation of the second layer at the edge areas. As long as the first layer remains below 0.7 μm thick, however, a very thick additional layer could be printed without any cracks. The printed patterns were mechanically robust and exhibited good electrical contact between the layers. The threshold pulse energy density for printing was measured to be 10 mJ/cm2 and this threshold level made it possible to print over square centimeters by a single pulse.