Cyanogen-free preplated 
copper solution belongs to the technical field of surface treatment 
electroplating. The solution adopts a nontoxic organic 
phosphine compound to replace 
cyanide as a complexing agent for the preplated 
copper, and is particularly suitable for preplated 
copper used to electroplate steel, aluminum, 
magnesium, 
zinc, 
titanium and 
titanium alloy. The 
cyanogen-free preplated copper solution has the following main technical characteristic that the solution consists of (a) one sort of copper sulphate, 
basic cupric carbonate or 
copper nitrate with the 
volume concentration of between 30 and 60 g / L; (b) one sort or two sorts of compounds selected from 
methylene diphosphonic acid, 1-hydroxyethylidene 1.1 diphosphonic acid and 1-hydroxybutyleneidene 1.1 diphosphonic acid with the 
volume concentration of between 120 and 160 g / L; (c) one sort or two sorts of compounds selected from methylamino dimethylene diphosphonic acid, hexamethylene 
diamine tetramethylene phosphonic acid and 
ethylenediamine tetramethylene phosphonic acid with the 
volume concentration of between 2 and 5 g / L; (d) one sort of 
potassium citrate, amine citrate or 
seignette salt with the volume concentration of between 6 and 12 g / L, and (e) polyethyleneimine 
alkyl slat or 
aliphatic amine ethoxy sulfonated substance (AESS) with the volume concentration of between 0.02 and 0.05 g / L. The 
cyanogen-free preplated copper solution has the characteristics of stable service performance, simple solution compositions, convenient maintenance, high safety, 
environmental protection, reliable plating coat binding and the like.