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 Sn 4+ and Sb 5+ in ATO is reduced to Sn 2+ and Sb 3+ , 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 × 10 7 Ω −1 m −1 ) and excellent stability over time. This study also provides a guideline to develop copper‐free laser sensitizer for LDS technology.