Sintering of solution-based aluminum nano-particles by laser ignition

We investigated self-propagating sintering of aluminum (Al) nano-particles (NPs) induced by laser ignition on inkderived films. An organic Al-NP ink was used as the precursor. A CW IR fiber laser (1064nm, IPG YLR-50 series with the maximum power of 50W) was used as the sintering source. Electrically-conductive Al wires were successfully processed on glass and silicon substrates, respectively. The sintered Al wire shows lower resistivity (~32μΩ·cm) on the glass substrate and higher resistivity (~150μΩ·cm) on the silicon substrate. N2 ambient helps to reduce electric resistivity by reducing oxidation. In addition to the sintering procedure and recipe, the sintered wires were characterized using a two-point probe, a scanning electric microscopy and a laser scanning microscopy. The laser heating process was simulated. We also discussed the mechanism of laser ignited sintering.