| 학회 | 한국고분자학회 |
| 학술대회 | 2005년 가을 (10/13 ~ 10/14, 제주 ICC) |
| 권호 | 30권 2호 |
| 발표분야 | 고분자 합성 |
| 제목 | A High-Performance Positive Working Photosensitive Polyimide: Effects of Reactive End Groups on the Physical Properties of the Films |
| 초록 | Photosensitive polyimides (PSPIs) have attracted much attention in recent year, because their use in microelectronics fabrication can reduce the number of processing steps required for obtaining the desired photolithographic pattern.1 The widest application of PSPIs is as the stress buffer layer of semiconductor applied after chip passivation. For such application, the PSPIs have to exhibit good mechanical and thermal properties to protect bare-chip from the stress that is induced by fillers in molding compound and thermal mismatch between passivation layer and molding compound. To improve the mechanical and thermal properties of positive working photosensitive polyimide (PSPI) films, we incorporated various reactive end-cappers into the ends of the polyimide (PI) precursor chains having low molecular weight.2 In this study, poly(amic acid)s (PAAs) as a base polymer of the positive working PSPIs were synthesized via ring-opening polymerization of 4,4’-oxydiphthalic anhydride and 4,4’-oxydianiline with four different reactive end-cappers (maleic anhydride (MA), citraconic anhydride (CA), 2,3-dimethylmaleic anhydride (DMA), and 5-norbornene-2,3-dicarboxylic anhydride (NDA)) to investigate the effects of reactive end-cappers on the performance of PI precursors and the resulting PI films. The PI films imidized from these end-capped PAAs induced the chain extension and cross-linking reactions of end-group, resulting in the improvement of the mechanical and thermal properties in spite of the low molecular weight of the precursors. However, the UV transmittance at ~365nm, which is an important property of PSPIs for thick-film applications such as stress buffer layer, was strongly influenced by the types of end-cappers used. MA and CA end-capped PAAs were found to increase the absorbance of PAA at 365nm due to the p-conjugation of their ring-opened structures. However, DMA and NDA end-capped PAAs have an appropriate transparent in this region for the applications. These behaviors were understood by the optimized geometries and the simulated UV-Visible spectra of modeled end-groups by density functional theory (DFT) calculations. Thus, the introduction of DMA and NDA end cappers are very effective in the improvement of performance of the positive working PSPIs. References 1. K. Horie, T. Yamashita, Photosensitive polyimides, fundamentals and applications; Technomic: Lancaster, 1995. 2. M. S. Jung, S. K. Jung, Y. Y. Park, B. S. Moon, B. K. Kim, US Patent 6,600,006. |
| 저자 | 정명섭, 박용영 |
| 소속 | 삼성종합기술원 |
| 키워드 | photosensitive polyimide; positive working; photolithography |
