THERMAL FUSION MULTILAYER POLYIMIDE FILM USING CROSSLINKED WATER-SOLUBLE THERMOPLASTIC POLYAMIC ACID, AND PREPARATION METHOD THEREOF

摘要

The present invention relates to a thermal fusion multilayer polyimide film capable of being used as a double-sided flexible copper clad laminate (FCCL) interlayer insulation material; and a preparation method of the thermal fusion multilayer polyimide film in-line coated with a coating solution of crosslinked water-soluble thermoplastic polyamic acid. The preparation method of the polyimide film according to the present invention is environment-friendly and economical because the method uses, as a diluting solvent, a coating solution of crosslinked water-soluble thermoplastic polyamic acid using water, instead of an expensive toxic organic solvent, and it is possible to in-line coat safely without a risk of explosion due to organic vapors. In addition, the thermal fusion multilayer polyimide film according to the present invention has excellent dimensional stability and strong interfacial adhesive properties, and therefore can be effectively used as an interlayer thermal fusion insulating material for producing a double-sided FCCL.