Printable Thick Copper Conductors from Optically Modulated Multi-Dimensional Particle Mixtures

Printing techniques that enable the formation of arbitrarily-designed architectures have been implemented in various research fields owing to their characteristic advantages in processing over other techniques. In particular, low-cost, printable conductors are of paramount importance in the production of highly functioning printed electronics. Among various candidates, copper (Cu) particle-based printable fluid has been regarded as the most promising constituent material in a conjunction with the use of the flash-light-sintering (FLS) process in air. In this study, we synthesized surface-oxidation suppressed Cu nanoparticles, sub-micron particles, and flakes to regulate the optical absorption characteristics in FLS-processed, Cu-based printed conductors. Our results revealed clearly that the critical issues in FLS-processed conductors, namely, undesirable crack formation and a limitation of thickness, are resolved by adjusting the optical behaviors of particulate layers by variation of the composition of ...