The effect of double scans and elliptical beam during sintering of silver nanoparticle structures via a modulated laser beam

Abstract

Sintering of silver (Ag) nanoparticle (NP) structures was carried out via a modulated laser beam. High scanning speeds were adopted during the scanning laser sintering process in a minimum time duration. With a laser exposure time of 67.7 ms, very low electrical resistivities of the Ag NP structures were achieved. Our numerical model predicted the enhanced electrical performance of the Ag NPs via a to-and-fro (double scanning) process. The experimental results confirmed the predictions, and lower resistivities were obtained with double scans as compared to single scans. For a more efficient continuous wave laser sintering, our temperature calculations predicted an approximately 37% energy efficiency when using an elliptical laser beam as compared to a circular laser beam. The efficiency of the elliptical beam was confirmed by the experimental results, and lower electrical resistivity by half was obtained as compared to oven sintering results.