Research and development of regenerating methods and equipments for acid cupric chloride etchants, have been stressed in prevention and control of pollution work in the business of printed circuit boards for clean production, ecosystem and people’s health.

Nanometer copper powders were prepared from acidic waste etching solution containing copper using hydrazine hydrate as a reductive agent.

Some new processes and technologies for electronics finishing were introduced, such as wafer plating, electrochemical mechanical polishing, microelectro-mechanical system plating, copper plating using insoluble anode, platinized niobium electrode, lead and cadmium free eleclroless nickel, recycling of alkaline etching solution and reclaiming system of copper.

A reagent for removing lead of alkaline waste etching liquid and its removing lead rate equation by quadratic orthogonal designing;