Self-adapting Grinding Method for Dismounting Through-hole Mounted Components from Scrapped Printed Circuit Board

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.