A New Type of Electroless Copper Plating with Iminodiacetic Acid as Complexing Agent

The effects of electrolyte composition on copper deposition rate and solution stability were investigated in acid electroless copper plating system with iminodiacetic acid as complexing agent and sodium hypophosphite as reducting agent.The results indicated that the deposition rate was enhanced with the increase in reaction temperature and concentrations of copper sulfide and sodium hypophosphite,while the deposition rate was decreased with the increase in iminodiacetic acid concentration and pH value.With the decrease in pH value,the cathodic reduction peak potential shifted positively,and the peak current density increased.Meanwhile the reduction of copper complex ions was accelerated,and the deposition rate of copper was improved.The morphology of the deposits was examined by scanning electron microscopy and atomic force microscopy.