Polyamic acid (PAA) was prepared from cyclobutane-1,2,3,4-tetracarboxylic dianhydride (CBDA) and 4,4′-diaminodiphenyl ether (DDE). In order to impart a photosensitivity to the PAA, diazonaphthoquinone (DNQ) derivative (DI) was added. However, the addition of the DI was not enough to inhibit the dissolution of the PAA for a aqueous alkali solution. Therefore, we had synthesized poly(amic acid ester)s by an adding 1,2-epoxy-3-phenoxypropane to the PAA. That is, an acidity of the PAA could be controlled by an esterification reaction of 1,2-epoxy-3-phenoxypropane with the PAA. Significant difference of a dissolution rate of the poly(amic acid ester) between an exposed and unexposed area was observed at an acid content of 60% and less. Resolution of the positively patterned film showed about 25 μm at the exposure dose of 200 mJ/cm2.

1,2,3,4-시클로부탄 테트라카복시산 이무수물과 4,4′-디아미노디페닐에테르(DDE)를 용액 중합 반응하여 폴리암산(PAA) 용액을 제조한 후, 1,2-에폭시-3-페녹시프로판과 반응시켜 폴리암산에스테르(PAE)를 합성하였다. 여기에 용해억제재로서 30 wt%의 디아조나프토퀴논 유도체(DI)를 첨가하였다. 365∼400 nm의 파장에서 200 mJ/cm2의 자외광을 조사한 후, 0.95 wt%의 테트라메틸암모니움히드록사이드 수용액으로 현상한 결과 25 μm 해상도의 양성형 미세 화상을 얻었다. 비노광부에 잔존하는 폴리이미드 박막은 400 nm에서 92% 이상의 우수한 광투과도를 나타내었다.

Keywords: photosensitive; polyimide; alkali developable; good transmittance; photopatterning