| 摘要 |
This invention relates to flexible copper-clad circuit substrates in which a copper foil is directly and firmly jointed with a polyimide film. The polyimide used is obtained conventionally by reacting diamine components including 3,3'diaminobenzophenone, 1,3-bis(3-aminophenoxy)-benzene, 4,4'-bis(3-aminophenoxy)biphenyl, 2,2-bis¢4-(3-aminophenoxy)-phenyl!propane, 2,2-bis¢4-(3-aminophenoxy)phenyl! sulfide, bis¢4-(3-aminophe-noxy)phenyl! ketone and bis¢4-(3-aminophenoxy)phenyl! sulfone, with tetracarboxylic acld dianhydride including pyromellitic dianhydride, 3,3',4,4'-benzophenone tetracarboxylic dianhydride, 3,3',4,4'-biphenyl tetracarboxylic dianhydride and bis(3,4-dicar-boxyphenyl) either dianhydride, in organic solvent, and by thermally or chemically imidizing resultant polyamic acid. The polyimide thus obtained has relatively lower melt viscosity and is flowable at high temperatures. Therefore, the copper foil and the polyimide film were assembled, pressed by heating under pressure and further cured to afford the flexible copper-clad circuit substrates having the polyimide film firmly jointed with the copper foil. |
