REDUCTION OF METALLIC SURFACE OXIDES VIA AN ELECTROCHEMICALLY-GENERATED REDOX SPECIES

A new method is described for removing oxides from metallic surfaces v ia electroless reduction by the reducing member of a redox couple that is electrochemically regenerated in a closed loop. On tin-lead coatin gs, which are widely used to enhance the solderability retention of el ectronic components and circuit boards, naturally-formed oxides are re duced to the metallic state within ten seconds by either vanadous or c hromous ions in acidic sulfate solution. Wetting balance data for wire specimens show that this reduction treatment is an effective means of restoring and ensuring solderability.