Excimer Laser Ablation of High Aspect Ratio Microvias Using a Novel Sensitizer-Enhanced Photopolymer

Abstract

A new drop-in sensitizer has been developed for use with COTS negative tone photoresist to facilitate the laser fabrication of high aspect ratio microstructures in a thick film of photopolymer. Microvias with diameters as small as 50 μm have been successfully laser ablated in a 160 μm thick layer of the sensitized photoresist. Ablation rates of up to 86 nm/pulse have been achieved with an excimer laser.