감광성 페이스트 및 후막리소그라피에 의한 미세패터닝 기술

Abstract

Thick film lithography applied photo-lithography in thin film process to conventional thick film process including screen-printing. This technology enables patterns to form finer resolution while compared to the conventional thick film process and a similar level of packaging density can be achieved when compared to thin film or etched thick film circuits. Because of the better edge definition than that of screen-printed patterns, thick film lithography draw a significant attention in the RF/Microwave and integrated LTCC module. In this research, low temperature cofireable ceramic so called LTCC dielectric and conductor pastes, which enabled the formation of thick film fine-via and line using photo-lithographic technology, were developed. The optimum composition for fine patterns was studied by varying the amounts of solid material powder, polymer-monomer ratio, and amount of photoinitiator. The effect of processing parameter such as UV-exposing dose on the formation of fine pattern was also tested. And formation of fine pattern was tested on LTCC green sheet after testing on soda-lime glass wafer as a substrate. The developed photoimageable pastes were printed on substrate, then dried, and exposed to UV-radiation. The formation of fine pattern was tested for multilayer with stacked layer of pastes. Fine pattern formed was a excellent, when buffer layer was coated on LTCC green sheet. As a result, it was found that the ratio of polymer to monomer, solid material loading and the amount of photo-initiator were the main factors affecting the resolution of fine pattern.