Dry Film Resist Stripping
Dry film photoresists have become the most widely used
plating and etching resists for photochemical machining operations.
They are classified into solvent, semi-aqueous and full
aqueous resists, based on the type of chemistry required to
ploce s the resist. Solvent resists use chlorinated solvents for both
developing and stripping. Semi-aqueous resists are developed in
a solution of weak alkali and water miscible solvent. Full aqueous
resists are usually developed with weak alkali alone. They can be
stripped in hot alkali, but performance of alkali-only strippers is
barely adequate for many production operations. Demands for
higher strip rates and loading force many users of aqueous resist
to use a semi-aqueous stripper: either a homebrew solution of a
glycol ether and caustic or a proprietary blend of chemicals.
Peter R. Rose and Thomas R. Meeker, Inland Specialty Chemicals