Generation of High Aspect Ratio Metal Microstructures Exhibiting Low Surface Roughness by Drop-wise Printing of Liquid Metal

Abstract

This paper presents the results of parameter studies for the drop-wise generation of metal microstructures from liquid metal. In this context, thin walls (170μm - 180μm thickness) featuring aspect ratios of over 50 are printed from solder droplets to identify the correlation between printing parameters and resulting material properties. Droplet spacing as well as substrate temperature are varied and the resulting surface quality in terms of roughness is evaluated. Best results, for given boundary conditions, are achieved with a relative droplet spacing of 0.65 in combination with a substrate temperature of 140°C. Based on printing with droplets of 170μm diameter a printed area surface roughness of 9.35μm is achieved.