Laser-direct process of Cu nano-ink to coat highly conductive and adhesive metallization patterns on plastic substrate

• Published in: Optics and lasers in engineering 2016-05, Vol.80, p.12-16
• Main Authors: Min, Hyungsuk, Lee, Byoungyoon, Jeong, Sooncheol, Lee, Myeongkyu
• Format: Article
• Language: English
• Subjects: Beams (radiation); Coating; ELECTRICAL CONDUCTIVITY; Flexible substrate; Formates; INKS; Laser sintering; LASERS; Metallizing; METALLIZING (FOR PLATING); MICROSTRUCTURES; Nano-ink; Nanostructure; Patterning; POLYIMIDES; SINTERING; Substrates
• ISSN: 0143-8166; 1873-0302
• DOI: 10.1016/j.optlaseng.2015.12.007

We here present a simple, low-cost laser-direct process to fabricate conductive Cu patterns on plastic substrate. A Cu nano-ink was synthesized using Cu formate as a precursor. The Cu ink spin-coated on a polyimide substrate was selectively sintered using a pulsed ultraviolet laser beam. The unexposed regions of the coated ink could be removed by rinsing the whole film in the dispersion agent of the synthesized ink, which revealed a conductive Cu pattern. This allowed sintering and patterning to be simultaneously accomplished, with a minimum line width of ~20μm available. The fabricated pattern remained strongly adhesive to the substrate and exhibited only a slight increase in resistance even after 1000 bending cycles to a radius of curvature of 4.8mm. •A Cu complex ink is synthesized using Cu formate as a precursor.•Conductive Cu patterns are fabricated on polyimide by selective laser sintering of the ink.•The fabricated pattern exhibits strong adhesion to the substrate under cycled bending test.