scholarly journals Combined Use of 3D and HSI for the Classification of Printed Circuit Board Components

2021 ◽  
Vol 11 (18) ◽  
pp. 8424
Author(s):  
Songuel Polat ◽  
Alain Tremeau ◽  
Frank Boochs

Successful recycling of electronic waste requires accurate separation of materials such as plastics, PCBs and electronic components on PCBs (capacitors, transistors, etc.). This article therefore proposes a vision approach based on a combination of 3D and HSI data, relying on the mutual support of the datasets to compensate existing weaknesses when using single 3D- and HSI-Sensors. The combined dataset serves as a basis for the extraction of geometric and spectral features. The classification is performed and evaluated based on these extracted features which are exploited through rules. The efficiency of the proposed approach is demonstrated using real electronic waste and leads to convincing results with an overall accuracy (OA) of 98.24%. To illustrate that the addition of 3D data has added value, a comparison is also performed with an SVM classification based only on hyperspectral data.

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

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.


2021 ◽  
Vol ahead-of-print (ahead-of-print) ◽  
Author(s):  
Ioan Doroftei ◽  
Daniel Chirita ◽  
Ciprian Stamate ◽  
Stelian Cazan ◽  
Carlos Pascal ◽  
...  

Purpose The mass electronics sector is one of the most critical sources of waste, in terms of volume and content with dangerous effects on the environment. The purpose of this study is to provide an automated and accurate dismantling system that can improve the outcome of recycling. Design/methodology/approach Following a short introduction, the paper details the implementation layout and highlights the advantages of using a custom architecture for the automated dismantling of printed circuit board waste. Findings Currently, the amount of electronic waste is impressive while manual dismantling is a very common and non-efficient approach. Designing an automatic procedure that can be replicated, is one of the tasks for efficient electronic waste recovery. This paper proposes an automated dismantling system for the advanced recovery of particular waste materials from computer and telecommunications equipment. The automated dismantling architecture is built using a robotic system, a custom device and an eye-to-hand configuration for a stereo vision system. Originality/value The proposed approach is innovative because of its custom device design. The custom device is built using a programmable screwdriver combined with an innovative rotary dismantling tool. The dismantling torque can be tuned empirically.


2017 ◽  
Vol 29 (3) ◽  
pp. 164-170 ◽  
Author(s):  
Hao Wu

Purpose This paper aims to inspect the defects of solder joints of printed circuit board in real-time production line, simple computing and high accuracy are primary consideration factors for feature extraction and classification algorithm. Design/methodology/approach In this study, the author presents an ensemble method for the classification of solder joint defects. The new method is based on extracting the color and geometry features after solder image acquisition and using decision trees to guarantee the algorithm’s running executive efficiency. To improve algorithm accuracy, the author proposes an ensemble method of random forest which combined several trees for the classification of solder joints. Findings The proposed method has been tested using 280 samples of solder joints, including good and various defect types, for experiments. The results show that the proposed method has a high accuracy. Originality/value The author extracted the color and geometry features and used decision trees to guarantee the algorithm's running executive efficiency. To improve the algorithm accuracy, the author proposes using an ensemble method of random forest which combined several trees for the classification of solder joints. The results show that the proposed method has a high accuracy.


2021 ◽  
Author(s):  
Jiheong Kang ◽  
Wonbeom Lee ◽  
Hyunjun Kim ◽  
Inho Kang ◽  
Hongjun Park ◽  
...  

Abstract Stretchable electronics are considered next-generation electronic devices in a broad range of emerging fields, including soft robotics1,2, biomedical devices3,4, human-machine interfaces5,6, and virtual or augmented reality devices7,8. A stretchable printed circuit board (S-PCB) is a basic conductive framework for the facile assembly of system-level stretchable electronics with various electronic components. Since an S-PCB is responsible for electrical communications between numerous electronic components, the conductive lines in S-PCB should strictly satisfy the following features: (i) metallic conductivity, (ii) constant electrical resistance during dynamic stretching, and (iii) tough interface bonding with various components9. Despite recent significant advances in intrinsically stretchable conductors10,11,12, they cannot simultaneously satisfy the above stringent requirements. Here, we present a new concept of conductive liquid network-based elastic conductors. These conductors are based on unprecedented liquid metal particles assembled network (LMPNet) and an elastomer. The unique assembled network structure and reconfigurable nature of the LMPNet conductor enabled high conductivity, high stretchability, tough adhesion, and imperceptible resistance changes under large strains, which enabled the first elastic-PCB (E-PCB) technology. We synthesized LMPNet through an acoustic field-driven cavitation event in the solid state. When an acoustic field is applied, liquid metal nanoparticles (LMPnano) are remarkably generated from original LMPs and assemble into a highly conductive particle network (LMPNet). Finally, we demonstrated a multi-layered E-PCB, in which various electronic components were integrated with tough adhesion to form a highly stretchable health monitoring system. Since our synthesis of LMPNet is universal, we could synthesize LMPNet in various polymers, including hydrogel, self-healing elastomer and photoresist and add new functions to LMPNet.


2015 ◽  
Vol 2015 (1) ◽  
pp. 000707-000712 ◽  
Author(s):  
Michael G. Béda

The “Steinberg Criterion” is a well-known method for determining the fatigue life of Printed Circuit Board (PCB) components based on the deflection of the PCB. It has been adopted as a de facto industry standard for the fatigue analysis of electronic components, and has been successfully used on many programs. However it has some limitations. Steinberg derived this equation to describe the behavior of rectangular PCBs simply supported on all sides. In this configuration the deformed shape of the first mode of a PCB under vibratory loads is assumed by Steinberg to be described by two perpendicular half sine waves. Unfortunately many PCBs have distorted mode shapes as a result of clamped or asymmetric edge constraints, stiffeners, or irregular PCB outline. Finite Element Models (FEMs) can be used to predict mode shapes for these PCBs, but there has been no clear way to use Steinberg's equation to determine the fatigue margin for components on such boards. The traditional method (when the discrepancy is addressed) is to use a value for PCB length in the equation based on an approximation of the length of an equivalent half sine wave superimposed on the predicted mode shape. This approach, while better than ignoring the problem, can lead to inconsistency in results or the overlooking of localized effects, and in the case of extremely odd mode shapes can be nearly impossible. This paper presents a method of using FEM data for curvature as well as deflection at a single location to eliminate the shape and location variables from the Steinberg criterion, allowing it to be applied confidently to PCBs and Printed Wiring Assemblies (PWAs) with any shape and boundary conditions. Test cases are described that show equivalence between this method and the existing Steinberg criterion. Lastly the methodology used to extract phase-consistent curvature and deflection results from FEM analysis is briefly discussed.


1987 ◽  
Vol 12 (3) ◽  
pp. 167-186 ◽  
Author(s):  
E. H.L.J. Dekker ◽  
C. J.M. Lasance

The thermal properties of electronic components partly determine the reliability of electronic equipment. For electrolytic capacitors, they also set the limits for the ripple current and voltage values.This article first discusses the voltage limits under various conditions of temperature, frequency and polarity. Then the connection of ripple current to these parameters and to the capacitor's resistance is treated.An extensive analysis is made of the influence of heat conduction in the capacitor and the printed-circuit board, for metal-cased as well as for epoxy-coated pearl types. The study pays particular attention to solid aluminium capacitors containing a manganese dioxide semiconductor. They have some extraordinary properties: a temperature range of at least – 80 to + 175℃, and an appreciable reverse voltage potential.These can be fully employed to improve the ripple-current specification.


2020 ◽  
pp. 0734242X2095284
Author(s):  
Amit Kumar ◽  
Maria E Holuszko ◽  
Travis Janke

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.


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