The new photosensitive polyamic acid ester, PSPAE(BTDA-BBPA-HEMA), was synthesized by using BTDA and BBPA as an acid dianhydride and a diamine, respectively. After dissolving PSPAE(BTDA-BBPA-HEMA) in NMP, TEGDA (crosslinker) and Irgacure 819 (photoinitiator) were added to produce a negative photosensitive PSPAE composition. The polyimide film (PI-F1) was prepared by spin coating of the PSPAE composition followed by imidization of PSPAE-F1 at 350 ℃. The TGA curves of PSPAE-F1 and PI-F1 films were recorded and the thermal behavior was investigated. The PSPAE film was photopatterned and imidized to produce the patterned PI film having a resolution of 20-100 μm and a thickness of 20 μm. In addition, the film reduction rate after imidization was about 25%, which was remarkably improved compared with that (40-50%) of the conventional PSPAE (PMDA-ODA-HEMA) products.

BTDA 산이무수물과 BBPA 디아민을 사용하여 새로운 감광성 폴리아믹산 에스테르인 PSPAE(BTDA-BBPAHEMA) 를 합성하였다. PSPAE(BTDA-BBPA-HEMA)를 NMP에 녹인 후 TEGDA(가교제), Irgacure 819(광개시제)를 첨가하여 네가티브 감광성 PSPAE 조성물을 제조하였다. PSPAE 조성물을 스핀코팅하여 제조한 PSPAE-F1 필름을 350 ℃에서 이미드화하여 폴리이미드 필름(PI-F1)을 얻었다. PSPAE-F1과 PI-F1 필름의 TGA 곡선을 기록하고 열적거동을 조사하였다. PSPAE 필름을 광패터닝 후 이미드화를 실시하여 20-100 μm의 해상도와 20 μm 두께를 갖는 패터닝된 PI 필름을 제조하였다. 또한 이미드화 후 막두께 감소율은 약 25%로 측정되었으며 이는 기존 PSPAE(PMDA-ODA-HEMA) 제품의 막두께 감소율(40-50%)과 비교하여 현저히 향상되었다.

Keywords: photosensitive poly(amic acid ester), synthesis, formulation, photopatterning, film thickness