Three-component negative-type photosensitive polyimide precursor based on poly(amic acid), a crosslinker, and a photoacid generator

Abstract

A new negative-working and alkaline-developable photosensitive polyimide precursor based on poly(amic acid) (PAA), 4,4′-methylenebis[2,6-bis(hydroxymethyl)]phenol (MBHP) as a crosslinker, and a photoacid generator (5-propylsulfonyloxyimino-5H-thiophen-2-ylidene)-2-(methylphenyl)acetonitrile (PTMA) has been developed. PAA was prepared by ring-opening polymerization of pyromellitic dianhydride with 4,4′-oxydianiline. The photosensitive polyimide precursor containing PAA (65 wt %), MBHP (25 wt %), and PTMA (10 wt %) showed a clear negative image featuring 10 μm line and space patterns when it was exposed to 436 nm light at 100 mJ·cm−2, post-exposure baked at 130 °C for 3 min, followed by developing with a 2.38 wt % aqueous tetramethylammonium hydroxide solution at 25 °C. © 2004 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 43: 593–599, 2005