SOLUTION EQUILIBRIUM CHARACTERISTICS OF ELECTROLESS COPPER DEPOSITIONON THERMALLY-ACTIVATED PALLADIUM-CATALYZED POLYIMIDE SUBSTRATES

Solution equilibrium characteristics of two electroless copper baths c ontaining EDTA and tartrate as the complexing agents were studied as f unctions of pH. Equilibrium diagrams were constructed for both Cu-tart rate and Cu-EDTA systems. It was determined that copper is chiefly com plexed as Cu2L2 in acidic conditions and as Cu(OH)(2)L-2(-4) in alkali ne conditions in the tartrate bath, and as CuA(-2) in the EDTA bath, w here L and A are the complexing tartrate and EDTA ligands, respectivel y. Electroless copper deposition rates were studied from a tartrate ba th on thermally activated palladium-catalysed polyimide substrates as functions of copper and formaldehyde concentrations, and pH.