scholarly journals Estimating Recycling Return of Integrated Circuits Using Computer Vision on Printed Circuit Boards

2021 ◽  
Vol 11 (6) ◽  
pp. 2808
Author(s):  
Leandro H. de S. Silva ◽  
Agostinho A. F. Júnior ◽  
George O. A. Azevedo ◽  
Sergio C. Oliveira ◽  
Bruno J. T. Fernandes
Keyword(s):  
Integrated Circuits ◽  
Printed Circuit Boards ◽  
Printed Circuit Board ◽  
Electronic Waste ◽  
Decision Criterion ◽  
Economic Feasibility ◽  
Electronic Equipment ◽  
Circuit Board ◽  
Mechanical Recycling ◽  
Printed Circuit

The technological growth of the last decades has brought many improvements in daily life, but also concerns on how to deal with electronic waste. Electrical and electronic equipment waste is the fastest-growing rate in the industrialized world. One of the elements of electronic equipment is the printed circuit board (PCB) and almost every electronic equipment has a PCB inside it. While waste PCB (WPCB) recycling may result in the recovery of potentially precious materials and the reuse of some components, it is a challenging task because its composition diversity requires a cautious pre-processing stage to achieve optimal recycling outcomes. Our research focused on proposing a method to evaluate the economic feasibility of recycling integrated circuits (ICs) from WPCB. The proposed method can help decide whether to dismantle a separate WPCB before the physical or mechanical recycling process and consists of estimating the IC area from a WPCB, calculating the IC’s weight using surface density, and estimating how much metal can be recovered by recycling those ICs. To estimate the IC area in a WPCB, we used a state-of-the-art object detection deep learning model (YOLO) and the PCB DSLR image dataset to detect the WPCB’s ICs. Regarding IC detection, the best result was obtained with the partitioned analysis of each image through a sliding window, thus creating new images of smaller dimensions, reaching 86.77% mAP. As a final result, we estimate that the Deep PCB Dataset has a total of 1079.18 g of ICs, from which it would be possible to recover at least 909.94 g of metals and silicon elements from all WPCBs’ ICs. Since there is a high variability in the compositions of WPCBs, it is possible to calculate the gross income for each WPCB and use it as a decision criterion for the type of pre-processing.

Analysis of rejects from waste printed circuit board processing as an alternative fuel for the cement industry

2020 ◽  
pp. 0734242X2095284
Author(s):  
Amit Kumar ◽  
Maria E Holuszko ◽  
Travis Janke
Keyword(s):  
Printed Circuit Boards ◽  
Printed Circuit Board ◽  
Electronic Waste ◽  
Precious Metals ◽  
Calorific Value ◽  
Alternative Fuel ◽  
Organic Content ◽  
Cement Industry ◽  
Circuit Board ◽  
Printed Circuit

Waste Printed circuit boards (PCBs) are one of the most valuable and recycled components of electronic waste due to the presence of precious metals such as copper, silver, gold and palladium. The rejects of the PCB recycling process, named non-metal fraction (NMF) have continuously been sent to landfills. Several researchers have proposed alternative use of NMF as secondary materials such as fillers in composites or as adsorbent. This study is focused on the potential application of the PCB recycling rejects as waste-derived fuel or alternative fuel in the cement industry. Approximately 2 million metric tonnes (Mt) of this waste was produced in 2014 globally and estimated to reach 6.5 million Mt in 2050. The presence of high organic matter in the NMF renders it useful as an alternative fuel. The organic content of the NMF could also potentially be increased using gravity separation and thus increasing its net calorific value. The study showed that the NMF could provide up to 21 MJ kg-1 of heating value with low heavy metal and ash concentration. A comparison with other waste-derived fuel sources is also presented in the paper.

Comparison of Leaching Processes of Gold and Copper from Printed Circuit Boards of Waste Mobile Phone

2014 ◽  
Vol 955-959 ◽  
pp. 2743-2746 ◽  
Author(s):  
Jian Feng Yin ◽  
Si Hui Zhan ◽  
He Xu
Keyword(s):  
Mobile Phone ◽  
Inductively Coupled Plasma ◽  
Printed Circuit Boards ◽  
Printed Circuit Board ◽  
Electronic Waste ◽  
Precious Metals ◽  
Optical Emission ◽  
Optimal Choice ◽  
Circuit Board ◽  
Printed Circuit

Waste mobile phone has become the largest number of electronic waste, and recycling of metals from mobile phone would ensure resource recycling and reduce environmental degradation. Based on the contents of metals analyzed by Inductively Coupled Plasma Optical Emission Spectrometer (ICP-OES), containing copper and precious metals such as gold, the paper compared the extraction processes of gold, copper from waste mobile phone printed circuit board (PCB). In this study, two processes, nitric acid and thiourea (NT), sulfuric acid-hydrogen peroxide and iodine (SAHPI) were used to leach copper and gold, respectively. The recovery rate of copper was found to be 96.42%, and 94.3% of the gold was leached in the former process. Similar trends were obtained for the leaching of copper and gold in the latter process, but it was lower that about 95.27% of copper was recycled, while 93.4% of gold were leached. Both the two processes were nontoxic and non-cyanide system. However, thiourea is not stable and easy to decompose in alkaline solution, and the technology has disadvantage of instability. Iodine leaching on the other hand is comparatively a environmental process. Therefore, the optimal choice is the combined process of SAHPI method, while further research is required to develop cost effective and environmentally friendly processes.

Pyrolysis of Waste Printed Circuit Board Particles

2015 ◽  
Vol 4 (2) ◽  
pp. 70-75
Author(s):  
Şule Atasever ◽  
Pınar A. Bozkurt ◽  
Muammer Canel
Keyword(s):  
Printed Circuit Boards ◽  
Printed Circuit Board ◽  
Electronic Waste ◽  
Circuit Board ◽  
Electronic Apparatus ◽  
Printed Circuit ◽  
Waste Printed Circuit Boards ◽  
Waste Printed Circuit Board ◽  
Different Temperatures ◽  
Apparatus And Instruments

Electrical and electronic apparatus and instruments which are obsolete value in use or completion of the life can be defined as e-waste. E-waste is one of the fastest growing types of hazardous waste. Printed circuit boards a major component of this waste. In this study, printed circuit board particles of mobile phone (MPCB) were used as electronic waste. MPCB waste was obtained from a local electronic waste factory. The elemental analysis and ICP-MS analysis were performed on these electronic wastes and thereafter pyrolysis runs were carried out between 500 and 900°C in a horizontal furnace. The liquid yields were determined and compared at different temperatures.

scholarly journals Microorganisms and Plants in the Recovery of Metals from the Printed Circuit Boards of Computers and Cell Phones: A Mini Review

Metals ◽  
2020 ◽  
Vol 10 (9) ◽  
pp. 1120 ◽  
Author(s):  
Rosalba Argumedo-Delira ◽  
María Esther Díaz-Martínez ◽  
Mario Javier Gómez-Martínez
Keyword(s):  
Printed Circuit Boards ◽  
Printed Circuit Board ◽  
Cell Phones ◽  
Electronic Equipment ◽  
Circuit Board ◽  
Printed Circuit ◽  
High Metal Content ◽  
Industrial Level ◽  
Biological Methods ◽  
Microelectronic Components

Most electrical and electronic equipment contain a printed circuit board (PCB), which is the board on which microelectronic components are mounted. The PCBs of obsolete and discarded electrical and electronic equipment are a material of great value due to their high metal content that is of commercial importance (i.e., Au, Ag, Pd, Pt, Ir, Ti, Ge, Si, Al, Cu, Ni, Zn, Fe, Sn, As, and Pb). Hydrometallurgical and pyrometallurgical methods have been used to extract metals from PCBs; however, these methods have energy and environmental disadvantages, which is why in recent years sustainable alternatives have been sought. Among these alternatives are the biological methods that contemplate the use of microorganisms and plants to recover metals from PCBs. In this review, only studies specifying the use of bacteria, fungi, and plants in the recovery of metals from the PCBs of computers and cell phones were considered, since the metallic composition of these plates varies according to the electronic equipment. In addition, the challenges and recommendations for these biotechnological processes to be improved and implemented at the industrial level in the coming years are discussed.

scholarly journals Recovery of Metals from Printed Circuit Boards By Means of Electrostatic Separation

2020 ◽  
Vol 28 (4) ◽  
pp. 213-219
Author(s):  
Dawid Franke ◽  
Tomasz Suponik ◽  
Paweł M. Nuckowski ◽  
Klaudiusz Gołombek ◽  
Kamila Hyra
Keyword(s):  
Waste Management ◽  
Printed Circuit Boards ◽  
Printed Circuit Board ◽  
New Technologies ◽  
Negative Impact ◽  
Electronic Waste ◽  
Circuit Board ◽  
Circuit Boards ◽  
Electrostatic Separation ◽  
Printed Circuit

AbstractWithout the use of appropriate recycling technologies, the growing amount of electronic waste in the world can be a threat to the development of new technologies, and in the case of improper waste management, may have a negative impact on the environment. This is due to the fact that this waste contains large amounts of valuable metals and toxic polymers. Therefore, it should be recycled in accordance with the assumptions of the circular economy. The methods of mechanical recovery of metals from electronic waste, including printed circuits, may be widely used in the future by waste management companies as well as metal production and processing companies. That is why, a well-known and easily applicable electrostatic separation (ES) method was used to recover metals from printed circuit boards. The grain class of 0.32 - 0.10 mm, obtained after grinding the boards, was fed to a separator. Feed and separation products were analyzed by means of ICP-AES, SEM/EDS and XRD. The concentrate yield obtained after electrostatic separation amounted to 32.3% of the feed. Its density was 11.1 g/cc. Out of the 91.44% elements identified in the concentrate, over 90% were metals. XRD, SEM observations and EDS analysis confirmed the presence of non-metallic materials in the concentrate. This relatively high content of impurities indicates the need to grind printed circuit board into grain classes smaller than 0.32-0.10 mm.

scholarly journals Advanced Recovery Techniques for Waste Materials from IT and Telecommunication Equipment Printed Circuit Boards

2019 ◽  
Vol 12 (1) ◽  
pp. 74 ◽  
Author(s):  
Horațiu Vermeșan ◽  
Ancuța-Elena Tiuc ◽  
Marius Purcar
Keyword(s):  
Flame Retardants ◽  
Printed Circuit Boards ◽  
Printed Circuit Board ◽  
Raw Materials ◽  
Circuit Board ◽  
Chain Process ◽  
Mechanical Recycling ◽  
Printed Circuit ◽  
Telecommunication Equipment ◽  
Recycling Techniques

Waste from information technology (IT) and telecommunication equipment (WITTE) constitutes a significant fraction of waste from electrical and electronic equipment (WEEE). The presence of rare metals and hazardous materials (e.g., heavy metals or flame retardants) makes the necessary recycling procedures difficult and expensive. Important efforts are being made for Waste Printed Circuit Board (WPCB) recycling because, even if they only amount to 5–10% of the WITTE weight, they constitute up to 80% of the recovered value. This paper summarizes the recycling techniques applicable to WPCBs. In the first part, dismantling and mechanical recycling techniques are presented. Within the frame of electro-mechanical separation technology, the chain process of shredding, washing, and sieving, followed by one or a combination of magnetic, eddy current, corona electrostatic, triboelectrostatic, or gravity separation techniques, is presented. The chemical and electrochemical processes are of utmost importance for the fine separation of metals coming from complex equipment such as WPCBs. Thermal recycling techniques such as pyrolysis and thermal treatment are presented as complementary solutions for achieving both an extra separation stage and thermal energy. As the recycling processes of WPCBs require adequate, efficient, and ecological recycling techniques, the aim of this survey is to identify and highlight the most important ones. Due to the high economic value of the resulting raw materials relative to the WPCBs’ weight and composition, their recycling represents both a necessary environmental protection action, as well as an economic opportunity.

PROCESS IMPACTS ON RELIABILITY OF PRINTED CIRCUIT BOARDS

2018 ◽  
pp. 6-9
Author(s):  
O. A. Korotky ◽  
A. A. Korneev ◽  
A. Yu. Galkin
Keyword(s):  
Printed Circuit Boards ◽  
Printed Circuit Board ◽  
Electronic Equipment ◽  
Circuit Board ◽  
Circuit Boards ◽  
Printed Circuit ◽  
Warranty Period ◽  
Complex Technical Systems ◽  
The Military

The paper considers defects that directly affect the quality of the finished product, which includes printed circuit boards and wiring connections. Current problems lead to failures of electronic equipment, which can lead to the failure of complex technical systems with subsequent downtime. Also methods for increasing the reliability of electronic equipment products are proposed, which exclude premature failures of the equipment as a whole. Such failures include breakage of the metallization column during extreme heating of the printed circuit board, poor connection quality of components on the board, absence of a layer between the component and the board. The method of preventing such problems is presented below in the text. Elimination of the above defects can lead to trouble-free operation throughout the warranty period of operation of the equipment at various facilities, including those in the military.

Study on the Promotion Effect of Microwave-Metal Discharge on the Microwave Pyrolysis of Electronic Waste

2015 ◽  
Vol 1088 ◽  
pp. 843-847 ◽  
Author(s):  
Jing Sun ◽  
Wen Long Wang ◽  
Chun Yuan Ma ◽  
Qin Yan Yue
Keyword(s):  
Printed Circuit Boards ◽  
Printed Circuit Board ◽  
Electronic Waste ◽  
Absorption Capacity ◽  
Circuit Board ◽  
Microwave Pyrolysis ◽  
Printed Circuit ◽  
Waste Printed Circuit Boards ◽  
Metal Discharge ◽  
In The Beginning

This paper discussed the role of microwave-metal discharge on the microwave induced pyrolysis of electronic waste. Two kinds of waste printed circuit boards (WPCB) were selected as the representatives of electronic waste and their pyrolysis processes under both conventional and microwave heating schemes were studied comparatively to reveal the effect of metal discharge. The copper-clad laminated printed circuit board (PCB) is deficient in absorbing microwaves, leading to inefficient microwave pyrolysis of this kind of electronic waste. The discharge caused by introducing metalliferous materials with metal tips or corners in the electromagnetic fields can result in high local temperature and complement the deficiency in the microwave absorption. The pyrolytic process can be promoted greatly by the thermal effect of discharge in the beginning and the enhanced consequent wave-absorption capacity as a result of the generated pyrolytic coke.

scholarly journals CHOOSING RATIONAL TRACING PROCEDURE BY CONSTRUCTIVE CRITERION

2019 ◽  
pp. 5-12
Author(s):  
Oleg Yu. Sisoev ◽  
Sergey S. Sokolov ◽  
Victor A. Tupik
Keyword(s):  
Integrated Circuits ◽  
Topological Space ◽  
Printed Circuit Boards ◽  
Printed Circuit Board ◽  
Mutual Influence ◽  
Buffer Zone ◽  
Circuit Board ◽  
Circuit Boards ◽  
Printed Circuit ◽  
Fine Pitch

The analysis of autorouter efficiency in the known CAD systems under structural and technological constraints is carried out. The revealed significant constraints are related to the thermal strength of the wires and possible mutual influence through the electromagnetic field. When manually designing the designer guided by his own experience, can ignore these and other constraints. Unlike a person, the autorouter strictly fulfills all the specified constraints, which, given the topology of the printed circuit board, does not allow tracing to complete. On the other hand, giving greater freedom to the autorouter often makes it impossible to meet the production requirements on permissible parameters of the topological pat-tern, which is the width of the conductors and the gaps between them. The problem of tracing printed circuit boards, including multilayer ones, has become much more complicated with the introduction of integrated circuits in TSOP, MOFP and BGA type enclosures packages with fine-pitch pins, a number of which can reach several hundred. The article investigates the possibility of maximizing printed circuit board topological space with these and other types of enclosures. The necessity of introducing a buffer zone around the component to improve the routing efficiency is explained. It is shown, however, that the avail-ability of a buffer zone does not eliminate the appearance of vias in it, the number of which depends on the routing type. On the basis of the proposed criterion for the autorouter performance, i.e. the ratio of the total wire length to the number of vias, the efficiency of using the topological space of a printed circuit board by three autorouters is analyzed.The presented experimental results of competing routing systems TopoR and Specctra confirmed the possibility to enlarge the pattern area of the printed circuit board for its further use.

scholarly journals Direct Chip Mounting — A Challenge to the Design Engineer

1982 ◽  
Vol 10 (1) ◽  
pp. 1-6
Author(s):  
J. Lorman ◽  
J. Prochaska
Keyword(s):  
Degrees Of Freedom ◽  
Printed Circuit Boards ◽  
Printed Circuit Board ◽  
Basic Element ◽  
Electronic Equipment ◽  
Circuit Board ◽  
Circuit Boards ◽  
Printed Circuit ◽  
High Degree ◽  
Good Possibility

The extrapolation of development trends in the area of technologically complicated electronic equipment shows an ever increasing complexity in semiconductor technology. This development has so concerned the constructors of electronic equipment that progress in the technology of mounting and interconnection has taken a secondary place.This growing divergence between a fast developing microelectronic industry, and a conservative state of the macroelectronics industry, is a driving force with regard to the progress to effective connection technologies at every level of mounting. The technological solution to all systems will then become more coordinated.The mounting of components to printed circuit boards is traditionally a soldering operation. This principle lead to the development of full automation, and is a standard mounting technology. The growth of integration at the chip level has however brought new requirements that are only satisfied with difficulty.Newly developed requirements show that the use of dual-in-line packages will be unsatisfactory. New methods must be designed to connect the chips directly to the printed circuit board, going from the chip as the smallest mounted unit.Requirements for very complex electronic equipment with a high degree of integration (LSI or VLSI) are not satisfied using traditional mounting systems. These require a totally new mounting concept, from the chips to the printed circuit board.In this paper alternatives to printed circuit board technology with insulated wiring (multilayers), and the mounting of chips from film carriers, are evaluated. These principles have a good possibility of further improvement as progress in mounting technology continues.Price reductions cause an extension of application possibilities and an extension of electronic designs. It is harder to make choices for new designs when there are more degrees of freedom. However the function of chips as the basic element is unchangeable and optimum designs need to be based on this concept.

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