Study On Separating Methods For Electronic Components And Solders From Waste PCBs

With the rapid development of science and technology, the electrical and electronicproducts are updating and renewing faster and faster, and the amount of electronicwastes including printed circuit boards (PCBs) is increasing at an alarming rate.Recycling waste PCBs has been the focus of recycling waste electrical and electronicproducts, the resource recovery of waste PCB boards satisfies the need of sustainabledevelopment. Based on the analysis and comparison of separating methods of electroniccomponents and solders from discarded PCBs at home and abroad, a kind of methodwhich can separate electronic components and solders from the waste PCBs is presentedthrough chemical reagents stripping and external force vibrating. A series ofexperiments are designed using orthogonal experiment method, the optimal chemicalparameters of separating electronic components and solders are obtained, and thechemical separating experiments with ultrasonic wave are also explored in the paper.The advantages and disadvantages of separating components and solders bymolten tin at home and abroad are analyzed. A series of separating experiments withmolten tin as heating medium are carried out. The limitation of this method is pointedout when separating electronic components and solders from waste PCBs polluted bydirt on the welding surface. A kind of method which separates electronic componentsand solders by molten tin with brown corundum as heating medium is proposed, and theappropriate size of the brown corundum is determined by experiments.Focused on the dismantling equipment being used by household appliancesrecycling enterprises and developed by our research group， a new crank-sliderimpacting device is designed to replace the original pneumatic impacting device.And the problem is solved that the former pneumatic impacting plate often stopsknocking. So the reliability of the dismantling equipment is improved, the disassemblyrate of the components is enhanced and the disassembly time is shortened.