Study On Key Technology Of Cyanide-free Copper Plating

A new environmental protection copper plating bath is proposed whose property is close to cyanide copper plating bath and which can be used to iron-base replacing the pre-nickel plating process.According to the cyanide copper plating technology, the requirements of cyanide-free copper plating process, must find a suitable non-cyanide ligands and additives.With a view to their joint role, the copper complex ion with the appropriate electrodeposition cathode polarization, and the ability to spread bath and integration of the crystalline coating reaches or exceeds the quality requirements of copper cyanide. Cyanide-free copper plating technology should meet the requirements of green, friendly environmental development. The investigation into the copmplex system is carried out based on electrode position for copper plating mainly composed of glycerol (C3H8O3) .Firstly,the process formula of the bath is investigated by the cathode polarization curve , Hull cell experiments , coating combination of performance test . Secondly,effect of composition on properties of the bath is investigated and the process parameters of the bath is studied by orthogonal test . Constantly adjusting and optimizing the performance of cyanide-free copper bath until the date was good.The results show that this Glycerol cyanide-free copper plating bath in the iron-based surface can be small, uniformly, toughly,and the combination of strong coating.This bath is very environmental-friendly. Using scanning electron microscopy (SEM) and spectrometer (EDAX) analyze the surface coating composition and structure,and analyzing pH,current density,auxiliary complexing agent coating on the surface of the impact.Under the suitable conditions the coating has a good appearance,high combination and low porosity.CSPM5000 atomic force microscope was used to characterize the coating micro-structure,the coating with very small particles,smooth surface and uniform distribution,very low porosity,is a good crystalline deposition layer.It is shown that the coating from the electroplating bath have good performance from misco-structure perspective.