Automated Disassembly Study Of Electronic Components Of Waste Mobile Phone Printed Circuit Boards

The rapid replacement of mobile phones brings a huge amount of waste mobile phones need to be disposed of,the waste printed circuit board(WPCB)is the core components of mobile phones,has a high reuse and resource value,improper disposal will bring more serious environmental hazards.At present,most of the waste mobile phone WPCB electronic components disassembly rely on manual,workers use a hot air gun or electric heating plate on the circuit board after heating with tweezers to separate components,in the heating process will release a variety of toxic and harmful substances.Therefore,the development of an efficient automated dismantling device for WPCB of waste mobile phones can replace manual labor to improve dismantling efficiency while freeing workers engaged in the industry from the harsh working environment and reducing health risks.In this study,the electronic component desoldering process of heating and desoldering the electron components on WPCB as a whole has realized the desoldering,overall desoldering and preliminary sorting of various electronic components on various types of waste mobile phone WPCB at one time.First of all,all kinds of components on the cell phone WPCB are mounted with SMD,the diagonal length of the chip components does not exceed 22 mm,and the individual mass is below 0.71g;the dismantling force model is established to determine the size of the dismantling force,and the results show that the dismantling force required in the vertical and horizontal directions is close to each other,and the dismantling force required for all kinds of typical chip components is between 3.14 m N and 152.78 m N,the dismantling acceleration required is between 1.36 g and 8.28 g,the excitation force of this device is set to 45° oblique upward,which can provide the same dismantling force in horizontal and vertical directions,and the amplitude of this device should be set to more than 3.66 mm.This provides the basic reference data for the design and manufacture of dismantling equipment.A dismantling device for WPCB electronic components of waste mobile phones,including heating and rotating feeding device and vibrating dismantling device,was designed and manufactured.The heating and rotating feeding device can preheat the waste mobile phone WPCB and transport it to the vibrating dismantling device in batches.The vibrating heating and dismantling device further heats up the used WPCB to reach the melting point of solder,desoldering the components and separating them from the substrate under the action of vibrating force.The finite element software ANSYS simulation modeling study shows that the structure of the dismantling device is reasonably designed and the temperature distribution is uniform,and after actual measurement,the results show that the temperature difference in the core area of dismantling can be controlled within 15℃.The actual dismantling study shows that the better operating parameters are preheating for 3 minutes,heating temperature of 250℃and amplitude of 4mm,which can achieve 98.14% dismantling rate of electronic components of WPCB of waste cell phone(without bottom filling glue)and nearly 100% dismantling rate of metal shield at one time.All kinds of components disassembled by this device are free of appearance damage,which is conducive to subsequent use.The absorption efficiency of three types of absorbent solutions for toluene was studied,and it was found that the best absorption effect was 1.0% Tween-20 with 1.0% n-butylamine absorbent solution,and the absorption rate of 380 ppm simulated toluene gas reached more than98%,and the average absorption rate of 10 min reached more than 95%;the configuration of the same capacity of absorbent solution 0.3% Tween-80 absorbent solution cost 83.17% less than that of 1.0% Tween-20 absorbent solution.The 10 min average absorption rate of 0.3%Tween-80 aqueous solution for toluene gas is about 93.8% only 4.17% lower than that of 1.0%Tween-20,and Tween-80 can be used to configure the absorption solution when meeting the emission requirements;the dismantling temperature of the equipment designed in this paper is reasonable,and the maximum VOCs concentration at the inlet is 0.4ppm during dismantling,and the maximum VOCs concentration at the outlet is 3.1ppm after simple treatment.The maximum VOCs concentration is 0.4ppm at the inlet and 3.1ppm at the outlet,which can meet the emission standard after simple treatment.