scholarly journals THERMOELECTRIC SYSTEM FOR PROVIDING A HEAT REGIME FOR MODULAR ELECTRONIC EQUIPMENT

2020 ◽  
Vol 46 (4) ◽  
pp. 53-64 ◽  
Author(s):  
Sh. A. Yusufov ◽  
A. M. Ibragimova ◽  
S. A. Peredkov ◽  
T. E. Sarkarov ◽  
R. G. Mitarov
Keyword(s):  
Printed Circuit Board ◽  
Cooling System ◽  
Air Flow ◽  
Experimental Studies ◽  
Operating Conditions ◽  
Electronic Equipment ◽  
Circuit Board ◽  
Thermoelectric Cooling ◽  
Printed Circuit ◽  
Testing Stand

Objectives. The article discusses a thermoelectric cooling system (TECS) for ensuring the thermal regime of modular electronic equipment (MEE) located in a cabinet. The main task of the experimental studies is to determine the temperature dependencies of the air-cooled heat-generating elements of a printed circuit board simulator according to TEСS parameters.Method. In order to conduct experimental studies of a thermoelectric cooling system for printed circuit boards in cassette units using a thermoelectric cooling system, a prototype designed and manufactured in the laboratory was studied on a testing stand.Result. The directions of constructive solutions for using a TECS device are presented along with a description of the testing stand and procedure. The dependencies of the temperature of the printed circuit board simulator on the heat power taken away by the TECS are considered along with the temperatures of hot and cold junctions, the air flow velocity and the distance between the electronic boards.Conclusion. The operability of the developed MEE cooling system is confirmed by the experimental studies; the specified cooling method has advantages over conventional forced or natural method and can achieve the temperatures required by the technical operating conditions; when choosing a fan to provide forced circulation of the air flow in the system, it is necessary to take into account the speed of the air flow in the channel; it is necessary to reserve the power of the power supply for the TECS operation in proportion to the power of the heat sources. An important additional point for the functioning of the thermoelectric cooling device is the necessity of ensuring the effective removal of heat from the hot junctions of the thermoelectric module without which it is impossible to use the proposed system. 

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.

Experimental studies on cryogenic recycling of printed circuit board

2006 ◽  
Vol 34 (7-8) ◽  
pp. 657-666 ◽  
Author(s):  
Chris Y. Yuan ◽  
Hong C. Zhang ◽  
Gregory McKenna ◽  
Carol Korzeniewski ◽  
Jianzhi Li
Keyword(s):  
Printed Circuit Board ◽  
Experimental Studies ◽  
Circuit Board ◽  
Printed Circuit

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.

The Disassembly Process and Apparatus of Waste Printed Circuit Board Assembly for Reusing the Components

2013 ◽  
Vol 457-458 ◽  
pp. 474-485
Author(s):  
Dong Xiang ◽  
Zu Fu Pang ◽  
Dan Feng Long ◽  
Peng Mou ◽  
Ji Ping Yang ◽  
...  
Keyword(s):  
Printed Circuit Board ◽  
Heating Temperature ◽  
Temperature Curve ◽  
Electronic Equipment ◽  
Circuit Board ◽  
Printed Circuit Board Assembly ◽  
Printed Circuit ◽  
Disassembly Process ◽  
Circuit Board Assembly ◽  
Heating Mode

Printed Circuit Board Assembly (PCBA), is an important basic part of Electric and Electronic Equipment, which has lots of high-value components and toxic substances. Normally, when Electric and Electronic Equipment (EEE) is scraped, some components on waste PCBA still keep good performances. Therefore, it is feasible and economical to environment-friendly reuse the high-value components on waste PCBA. In order to guarantee the quality of the disassembled components, the components reuse-oriented disassembly process is proposed, in which the mechanical and physical characteristics of solder and the joint type of PCBA are considered comprehensively. In the process, through the analysis and measurement of the temperature distribution of PCBA, the optimized heating mode and heating temperature curve can be drawn up for the different joint type of PCBA. For getting the disassembly mode of PCBA, the disassembly force and separating displacement of components on PCBA are defined and the disassembly energy models for different kinds of components are set up. On the basis of the heating mode, heating temperature curve and disassembly energy, two kinds of disassembly apparatus and a performance testing procedure for certain kinds of old components are developed. In the end the components reuse-oriented disassembly process parameters are optimized to get a high separation ratio and reuse ration of components with orthogonal test.

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