Enhanced surface coverage and conductivity of Cu complex ink-coated films by laser sintering

We here show that highly conductive copper films are obtainable from Cu complex ink by laser sintering. The synthesized Cu formate ink was spin-coated onto polyimide substrate and the coated films were scanned by an ultraviolet laser beam at 355 nm. During the sintering process, N2 gas was blown into the irradiated area to prevent oxidation. Unlike the typical thermal process, laser sintering resulted in tightly packed, dense structures. This made it possible to produce highly conducting thin films with uniform thickness. A minimum resistivity of 1.92 × 10− 5 Ω cm was obtained.