Printed circuit board manufacturing technology is a very complex, highly integrated processing technology. Especially in the wet process, the need to use a lot of water, so there are a variety of heavy metals in wastewater and organic waste water discharge, complex composition, processing more difficult. Press printed circuit board copper utilization of 30% to 40% are calculated, then the copper content in the waste, wastewater is quite substantial. By ten thousand square meters double panel calculations (foil thickness of 35 microns per side), the waste, the amount of wastewater containing copper have about 4500 kg, and there are a lot of other heavy metals and precious metals. These exist in the wastewater, wastewater metal if not treated on emissions, both caused by the waste and pollute the environment. Therefore, waste water treatment and recycling of copper and other metals in the PCB manufacturing process is of great significance, is PCB production indispensable part.
As we all know, the printed circuit board production process wastewater, which is a lot of copper, a very small amount of lead, tin, gold, silver, fluorine, ammonia, organic matter and organic complexes.
As for the process to produce copper wastewater, are: Shen copper, copper plating the entire board, graphics copper plating, etching, and before various PCB treatment processes (chemical pre-treatment, brush the front plate processing, ash grinding plates before processing, etc.).
Copper waste generated by the above process, its components can be divided into complex and non-complex wastewater effluent. For the wastewater discharge standards prescribed by the state, where the maximum allowable emissions of copper and its compounds at a concentration of 1mg / l (by copper dollars), must be for different wastewater containing copper, adopt different methods of wastewater treatment.