将废弃印制电路板(Printed circuit board,PCB)上的元器件拆解之后再分类,能有效提高后续材料分选和回收的效率。PCB上的插装式元器件由于引脚弯曲等原因,所需拆解力很大,常用的方法难以做到有效拆解。为解决这一困难,提出自适应磨削拆解方法,利用弹簧的自适应调节能力,在处理挠曲不平的PCB时提供较为平稳的法向磨削力。对自适应磨削系统的力学特性进行分析,结论显示在采用合理的磨削参数时,能够快速去除引脚并且不会过多地降低基板的刚度,证明了自适应磨削拆解方法的可行性。基于此自适应磨削系统的原理研制废弃PCB插装式元器件的引脚磨削拆解原型设备,并进行验证试验研究。试验结果表明此方法能够在轻微磨削基板的条件下高效地去除引脚,磨削后元器件的自动脱落率达到90%以上,并且未脱落的元器件与基板的连接强度大幅降低。
Efficiency of separating and recycling of materials of a scrapped printed circuit board(PCB) can be raised effectively through dismounting and sorting of components on the PCB.The through-hole mounted components are hard to dismount since the bended pins require great disassembling force.To tackle this problem,a dismounting method through removing the pins using self-adaptive grinding is presented,taking advantage of the self-adaptive adjustment ability of the springs to provide a relatively stable normal grinding force when grinding a warped PCB.The mechanical feature of the self-adaptive grinding system is analyzed,showing that with appropriate grinding parameters,the pins are removed rapidly while the stiffness of the base board is not significantly reduced.Consequently,the feasibility of this dismounting method is demonstrated.A prototypical device for dismounting through-hole mounted components from scrapped PCB is developed based on the principle of the self-adaptive grinding,and then experimental research is conducted to verify the analysis.Experimental results show that the pins are removed efficiently while the base board is slightly abraded.More than 90% through-hole mounted components fall off under gravity after grinding,and the joint strength of the remaining components is reduced significantly.