Effects of Oxygen Inhibition and Post-Processing on Exposure Controlled Projection Lithography Process Accuracy

摘要

Exposure Controlled Projection Lithography (ECPL) is a mask-projection stereolithography process which can be used to create micro lenses on flat or curved substrates. In the ECPL process, the ultraviolet light patterned by the dynamic mask passes through a transparent substrate to cure the photopolymer resin to a certain shape. The dimensions of the part can be controlled by the exposure time and functional pixels in the dynamic mask. In this paper, a modified process planning method is presented with the considerations of postprocessing and oxygen inhibition, which can vary part dimensions significantly. The effects of post-processing and oxygen inhibition are studied and characterized. The accuracy of the lateral and vertical dimensions of the cured part are improved by the revised method. Experimental validation is obtained by fabricating samples using the ECPL system.