Research On Complete Disassembly Process Equipment Of The Printed Circuit Boards

Waste Printed Circuit Boards (PCBs) need to be disassembled in the process of resource utilization. The centrifugal disassembly method of the PCBs has the advantages of big treatment capacity and dismantling the whole PCBs. But in the process of centrifugal disassembly of the PCBs, there are still three problems that the heating methods are not perfect; the disassembly is not complete and how to recycle the solder on the PCBs. In order to solve these problems, this thesis developed the PCBs complete disassembly device. And the centrifugal disassembly process of PCBs is studied. The main conclusions of this thesis are as follows:(1) The electronic components cannot be dismantled in the centrifugal disassembly process because the solder is still in the welding spot. The concept of Critical Separation Radius was put forward for the first time through the force analysis of the centrifugal disassembly process of the PCBs. And it sets up a complete disassembly theoretical model of the electronic components.(2) This thesis designs and manufactures the PCBs complete disassembly device of the PCBs. For the first time, the water or calcium chloride solution are put forward as the heating medium heating the PCBs. It solves the problem of how to clean the residual heating medium on the PCBs in the traditional liquid heating method.(3) Then the influence of the rotating time, temperature and rotating speed on the Critical Separation Radius are researched through experiments. The results show that the size of the Critical Separation Radius will be unchanged, when the rotating time exceeds 60 seconds; the size of the Critical Separation Radius decrease with the increasing of the temperature or the rotating speed. Then Critical Separation Radius on different operating condition is obtained. It solves the problem that the electronic components cannot be completely dismantled from the PCBs.(4) The numerical simulation method is carried out to study the flow field on the device. The results show that the device can recycle the solder in the process of disassembly. And due to the influence of the vortex in the ring gap of the device, the settling velocity of the solder will slow down with the increasing of the rotating speed.