| 摘要 |
PURPOSE:To enhance water resistance in etching without using chromic acid anhydride, by reacting maleic anhydride with a photo-crosslinked polyvinyl alcohol (PVA) film in 2 steps with heating in order to harden it. CONSTITUTION:A resist film prepared by photo-crosslinking a water soluble resist film of a combination of a PVA resin and a photosensitive agent is immersed in 50% maleic anhydride solution (a solution of a solvent, such as acetone or acetic ester not dissolving the resist film) at >=50 deg.C for several minutes-several tens minutes to form a half maleate. Subsequent heating at 150-250 deg.C for about 5- 30min cross-links and hardens the resist film, which is not swollen or flaked by an aqueous etching solution in the next etching step, thus permitting precise etching processing of a metal layer under the resist layer to be effected. |
