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Synthesis and characterization of a positive‐working, aqueous‐base‐developable photosensitive polyimide precursor
Author(s) -
Hsu Steve LienChung,
Lee PoI,
King JinnShing,
Jeng JyhLong
Publication year - 2002
Publication title -
journal of applied polymer science
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.575
H-Index - 166
eISSN - 1097-4628
pISSN - 0021-8995
DOI - 10.1002/app.10969
Subject(s) - tetramethylammonium hydroxide , polyimide , pyromellitic dianhydride , polymer chemistry , materials science , polymer , glass transition , aqueous solution , polymerization , fourier transform infrared spectroscopy , inherent viscosity , monomer , intrinsic viscosity , organic chemistry , chemistry , chemical engineering , composite material , layer (electronics) , engineering , nanotechnology
A positive‐working, aqueous‐base‐developable photosensitive polyimide precursor based on poly(amic ester)‐bearing phenolic hydroxyl groups and a diazonaphthoquinone photosensitive compound was developed. The poly(amic ester) was prepared from a direct polymerization of 2,2′‐bis‐(3‐amino‐4‐hydroxyphenyl)hexafluoropropane and bis( n ‐butyl)ester of pyromellitic acid in the presence of phenylphosphonic dichloride as an activator. Subsequently, the thermal imidization of the poly(amic ester) precursor at 300°C produced the corresponding polyimide. The inherent viscosity of the precursor polymer was 0.23 dL/g. The cyclized polyimide showed a glass‐transition temperature at 356°C and a 5% weight loss at 474°C in nitrogen. The structures of the precursor polymer and the fully cyclized polymer were characterized by Fourier transform infrared spectroscopy and 1 H‐NMR. The photosensitive polyimide precursor containing 25 wt % diazonaphthoquinone photoactive compound showed a sensitivity of 150 mJ/cm 2 and a contrast of 1.65 in a 3 μm film with 1.25 wt % tetramethylammonium hydroxide developer. A pattern with a resolution of 10 μm was obtained from this composition. © 2002 Wiley Periodicals, Inc. J Appl Polym Sci 86: 352–358, 2002