Comparative studies on thermal and laser sintering for highly conductive Cu films printable on plastic substrate

• Published in: Thin solid films 2012-01, Vol.520 (7), p.2878-2883
• Main Authors: Joo, Myungo, Lee, Byoungyoon, Jeong, Sooncheol, Lee, Myeongkyu
• Format: Article
• Language: English
• Subjects: Condensed matter: electronic structure, electrical, magnetic, and optical properties; Condensed matter: structure, mechanical and thermal properties; Conductive film; Cross-disciplinary physics: materials science; rheology; Cu paste; Electrical properties of specific thin films; Electronic structure and electrical properties of surfaces, interfaces, thin films and low-dimensional structures; Electronic transport phenomena in thin films and low-dimensional structures; Exact sciences and technology; Flexible substrate; Laser sintering; Materials science; Nanoscale materials and structures: fabrication and characterization; Other topics in nanoscale materials and structures; Physics; Sintering; Structure and morphology; thickness; Surfaces and interfaces; thin films and whiskers (structure and nonelectronic properties); Thin film structure and morphology
• ISSN: 0040-6090; 1879-2731
• DOI: 10.1016/j.tsf.2011.11.078

Compound-based Cu paste was synthesized to prepare electrically conductive films on plastic substrate. The Cu pastes screen-printed onto polyimide were annealed inside a furnace and also by an ultraviolet laser beam and the effects of annealing conditions on the microstructures and electrical properties were investigated. Both of thermal and laser processes were carried out under N2 gas flow, which was very effective in preventing oxidation. The minimum resistivity available with thermal sintering was 1.30×10−5Ωcm and a slightly higher resistivity was obtained by laser sintering. This value is several orders of magnitude lower than that reported for the copper nanoparticle paste thermally sintered under N2 atmosphere. The variation of microstructure and electrical property with the laser power was very similar to the temperature dependence of these factors in thermal sintering. ► Highly conductive Cu films are prepared on polyimide substrate. ► Thermal and laser sintering of printed Cu paste is conducted. ► Adherent sintered films with compact microstructure are obtained.