Parameters optimization of high stability bath for electroless copper plating

The stability of bath, the speed and the brightness of coating were taken as indexes to optimize the bath of electroless copper plating through the single factor experiment method. Electrochemical test of plating solution was done to study the influence of additives on polarization performance of bath. The stability of solution decreases with the concentration of Cu SO4·5H2O and HCHO increasing. The addition of appropriate complexing agent and stabilizers can effectively increase the stability of the plating solution. The copper deposition rate reaches to 4.93 μm/h for plating 30 min.The stable time of plating bath is more than two hours in 80 ℃ water bath. Copper layer appears shiny pale pink, and copper particles are close together. The magnitude of copper layer resistivity is 3.67×10–8 ?·m. The adhesion strength between copper layer and substrate is up to 10 N/mm2.