Laser Micromachining Technique of Nano-Particles Dispersed Polymer

Abstract

A new laser micromachining technique to realize high aspect ratio microstructure with free shaped wall using newly developed resist was proposed. The resist is made of ethylcellulose in which nano-particles with average diameter of 3.4 nm was dispersed. Since this resist has a strong absorption at wavelength of about 530 nm, it can be processed using focused low power output Nd: YVO4-SHG laser (CW, wavelength of 532 nm, power output of 23 mW). From the experiments, it was confirmed that the cross-sectional shape can be controlled by the Au concentration (1-50 wt%) and the laser beam power. The processed depth showed a strong dependency on Au concentration and showed maximum at 17 wt% Au concentration. From the theoretical calculation of the resist temperature rise and analysis of the processed resist surface, it was revealed that the Au aggregation at the bottom of the processed channel played an important role for the processed depth.