Comparative Study on the Performance of HEDP Copper Plating and Cyanide Copper Plating Processes

Abstract

In order to assess the potential for implementing the 1-hydroxyethylidene-1，1-diphosphonic acid (HEDP) copper plating process in engineering applications， copper coatings were prepared on the surfaces of A3 steel substrates using HEDP plating method and cyanide plating method.The macroscopic and microscopic morphologies， deposition rates， dispersion abilities， and deep plating capabilities of the copper coatings produced by the two processes were compared.Additionally， the coating adhesion and hydrogen embrittlement performance of the HEDP copper plating layer were characterized.Results showed that the HEDP copper plating layer exhibited fine crystallization with a dense distribution of grain grooves and undulations.The cyanide copper plating layer， on the other hand， displayed a granular structure with grains of varying sizes.At a current density of 1.0 A/dm2， the deposition rate of the HEDP copper coating reached 0.19 μm/min， which was 35.7%higher than the 0.14 μm/min deposition rate observed in the cyanide copper plating process.The dispersion and deep plating capabilities of both the HEDP and cyanide copper plating processes were found to be comparable.Additionally， the HEDP copper plating layer demonstrated good adhesion to the steel substrate and qualified hydrogen embrittlement performance.

Keywords

• copper electroplating； 1-hydroxyethylidene-1，1-diphosphonic acid； coating properties； porosity； passivation coating