Exposing Metal Oxide with Intrinsic Catalytic Activity by Near-Infrared Pulsed Laser: Laser-Induced Selective Metallization on Polymer Materials

In this work, a facile strategy is presented for the fabrication of precisely metallized patterns on polymer substrate based on the copper-free laser sensitizer through laser direct structuring (LDS) technology. A series of characterization methods are carried out to investigate the surface chemistry and morphology of polymer/antimony-doped tin oxide (ATO) composites after laser activation and selective metallization. X-ray photoelectron spectroscopy results show that a small part of Sn4+ and Sb5+ in ATO is reduced to Sn2+ and Sb3+, and it does not detect any Sn-0 (elemental tin) after laser activation. This study confirms that ATO is a good copper-free laser sensitizer and an efficient catalyst for selective metallization. Furthermore, the obtained copper layer is anchoring into the substrate leading to a superior adhesion property (highest 5 B level after Scotch tape test) between the copper layer and polymer substrate. Meanwhile, the obtained copper circuit line exhibits high conductivity (1.26 x 10(7) Omega(-1) m(-1)) and excellent stability over time. This study also provides a guideline to develop copper-free laser sensitizer for LDS technology.