scholarly journals A Novel ILP Formulation for PCB Maintenance Considering Electrical Measurements and Aging Factors: A “Right to Repair” Approach

Energies ◽  
2021 ◽  
Vol 15 (1) ◽  
pp. 183
Author(s):  
Panagiotis S. Karagiannopoulos ◽  
Nikolaos M. Manousakis ◽  
Constantinos S. Psomopoulos
Keyword(s):  
Printed Circuit Boards ◽  
Health Benefit ◽  
Circuit Boards ◽  
Electrical Measurements ◽  
Limited Budget ◽  
Conductive Substrate ◽  
Different Types ◽  
The Right ◽  
The Impact ◽  
Aging Factors

The design of longer-lasting products, such as domestic electric appliances, is a key-stone approach of the circular economy to reduce the use of non-reusable materials and the number of wastes to be managed at the end of the product’s life as well as to extend it. The manufacturing of modern electric appliances includes the incorporation of printed circuit boards (PCBs). PCBs provide mechanical support and electrically connect electrical or electronic components using conductive trackpads and other features etched from one or more sheet layers of copper laminated onto and/or between sheet layers of a non-conductive substrate. This paper proposes a PCB maintenance framework, fully compliant with the “Right to Repair” concept, considering the impact of their aging failures based on measurements made on them, as well as the repair and replacement costs of their components. Herein, we present an algorithm that assesses the problem of handling the repair and replacement cost corresponding to specific failures while ensuring that the total cost of repair does not exceed a predefined value. This is achieved through an integer linear programming (ILP) formulation which maximizes the benefit to the life expectancy, Li, of an appliance, constrained by a customer’s limited budget. The proposed methodology is tested with different PCBs and considers different types of appliances. More specifically, two cases concerning PCBs of washing and dishwasher machines are studied to examine the dependency of the solutions on the aging rate of their various components. The simulation results show that considering a medium budget, after 3 years, we can achieve a health benefit of 92.4% for a washing machine’s PCB, while for a dishwasher’s PCB, the health benefit drops to 86.3%.

scholarly journals Dismantling of Waste Printed Circuit Boards with the Simultaneous Recovery of Copper: Experimental Study and Process Modeling

Materials ◽  
2021 ◽  
Vol 14 (18) ◽  
pp. 5186
Author(s):  
Szabolcs Fogarasi ◽  
Árpád Imre-Lucaci ◽  
Florica Imre-Lucaci
Keyword(s):  
Environmental Performance ◽  
Printed Circuit Boards ◽  
Electrochemical Process ◽  
Circuit Boards ◽  
Electronic Components ◽  
Printed Circuit ◽  
Waste Printed Circuit Boards ◽  
Different Types ◽  
Leaching Solution ◽  
The Impact

The study was carried out with the aim to demonstrate the applicability of a combined chemical–electrochemical process for the dismantling of waste printed circuit boards (WPCBs) created from different types of electronic equipment. The concept implies a simple and less polluting process that allows the chemical dismantling of WPCBs with the simultaneous recovery of copper from the leaching solution and the regeneration of the leaching agent. In order to assess the performance of the dismantling process, various tests were performed on different types of WPCBs using the 0.3 M FeCl3 in 0.5 M HCl leaching system. The experimental results show that, through the leaching process, the electronic components (EC) together with other fractions can be efficiently dismounted from the surface of WPCBs, with the parallel electrowinning of copper from the copper rich leaching solution. In addition, the process was scaled up for the dismantling of 100 kg/h WPCBs and modeled and simulated using process flow modelling software ChemCAD in order to assess the impact of all steps and equipment on the technical and environmental performance of the overall process. According to the results, the dismantling of 1 kg of WPCBs requires a total energy of 0.48 kWh, and the process can be performed with an overall low environmental impact based on the obtained general environmental indexes (GEIs) values.

Nanovoid Formation at Cu/Cu/Cu Interconnections of Blind Microvias: A Field Study

2019 ◽  
Vol 2019 (1) ◽  
pp. 000492-000502 ◽  
Author(s):  
T. Bernhard ◽  
L. Gregoriades ◽  
S. Branagan ◽  
L. Stamp ◽  
E. Steinhäuser ◽  
...  
Keyword(s):  
Printed Circuit Boards ◽  
Structural Integrity ◽  
Weak Link ◽  
Critical Factor ◽  
Circuit Boards ◽  
Printed Circuit ◽  
Different Types ◽  
Key Factor ◽  
Electrical Reliability ◽  
The Impact

Abstract A key factor for a high electrical reliability of multilayer High Density Interconnection Printed Circuit Boards (HDI PCBs) is the thermomechanical stability of stacked microvia interconnections. With decreasing via sizes and higher numbers of interconnected layers, the structural integrity of these interconnections becomes a critical factor and is a topic of high interest in current research. The formation of nanovoids and inhibited Cu recrystallization across the interfaces are the two main indications of a weak link from the target pad to the filled via. Based on TEM/EDX measurements on a statistically relevant number of stacked and blind microvias produced in the industrial field, different types of nanovoid phenomena are revealed at the Cu/Cu/Cu junction. The types of nanovoids were categorized relating to the time of appearance (before or after thermal treatment), the affected interfaces or layers and the impact on the Cu recrystallization. The main root causes for each void type are identified and the expected impact on the thermomechanical stability of the via junction is discussed.

Noise properties of thin-film Ni-P resistors embedded in printed circuit boards

2013 ◽  
Vol 61 (3) ◽  
pp. 731-735
Author(s):  
A.W. Stadler ◽  
Z. Zawiślak ◽  
W. Stęplewski ◽  
A. Dziedzic
Keyword(s):  
Thin Film ◽  
Printed Circuit Boards ◽  
Circuit Boards ◽  
Noise Component ◽  
Printed Circuit ◽  
Resistance Bridge ◽  
Different Types ◽  
Signal Path ◽  
Resistance Fluctuations ◽  
Made In

Abstract. Noise studies of planar thin-film Ni-P resistors made in/on Printed Circuit Boards, both covered with two different types of cladding or uncladded have been described. The resistors have been made of the resistive-conductive-material (Ohmega-Ply©) of 100 Ώ/sq. Noise of the selected pairs of samples has been measured in the DC resistance bridge with a transformer as the first stage in a signal path. 1/f noise caused by resistance fluctuations has been found to be the main noise component. Parameters describing noise properties of the resistors have been calculated and then compared with the parameters of other previously studied thin- and thick-film resistive materials.

scholarly journals Effect of Graphite on Copper Bioleaching from Waste Printed Circuit Boards

Minerals ◽  
2020 ◽  
Vol 10 (1) ◽  
pp. 79 ◽  
Author(s):  
Linlin Tong ◽  
Qianfei Zhao ◽  
Ali Kamali ◽  
Wolfgang Sand ◽  
Hongying Yang
Keyword(s):  
Printed Circuit Boards ◽  
Acid Leaching ◽  
Circuit Boards ◽  
Printed Circuit ◽  
Waste Printed Circuit Boards ◽  
Copper Leaching ◽  
Initial Ph ◽  
Efficient Extraction ◽  
Bacteria Culture ◽  
The Impact

The efficient extraction of copper as a valuable metal from waste printed circuit boards (WPCBs) is currently attracting growing interest. Here, we systematically investigated the impact of bacteria on the efficiency of copper leaching from WPCBs, and evaluated the effect of graphite on bioleaching performance. The HQ0211 bacteria culture containing Acidithiobacillus ferrooxidans, Ferroplasma acidiphilum, and Leptospirillum ferriphilum enhanced Cu-leaching performance in either ferric sulfate and sulfuric acid leaching, so a final leaching of up to 76.2% was recorded after 5 days. With the addition of graphite, the percentage of copper leaching could be increased to 80.5%. Single-factor experiments confirmed the compatibility of graphite with the HQ0211 culture, and identified the optimal pulp density of WPCBs, the initial pH, and the graphite content to be 2% (w/v), 1.6, and 2.5 g/L, respectively.

scholarly journals Automatic Solder Joint Defect Classification using the Log-Gabor Filter

2010 ◽  
Vol 97-101 ◽  
pp. 2940-2943 ◽  
Author(s):  
Nang Seng Siri Mar ◽  
Clinton Fookes ◽  
K.D.V. Yarlagadda Prasad
Keyword(s):  
Solder Joint ◽  
Manufacturing Industry ◽  
Printed Circuit Boards ◽  
Distance Measure ◽  
Gabor Filter ◽  
Circuit Boards ◽  
Printed Circuit ◽  
Different Types ◽  
Gabor Filter Bank

This paper proposes the validity of a Gabor filter bank for feature extraction of solder joint images on Printed Circuit Boards (PCBs). A distance measure based on the Mahalanobis Cosine metric is also presented for classification of five different types of solder joints. From the experimental results, this methodology achieved high accuracy and a well generalised performance. This can be an effective method to reduce cost and improve quality in the production of PCBs in the manufacturing industry.

scholarly journals Soldering Electronics to Smart Textiles by Pulsed Nd:YAG Laser

Materials ◽  
2020 ◽  
Vol 13 (11) ◽  
pp. 2429
Author(s):  
Sebastian Micus ◽  
Michael Haupt ◽  
Götz T. Gresser
Keyword(s):  
Printed Circuit Boards ◽  
High Growth ◽  
Growth Potential ◽  
Circuit Boards ◽  
Smart Textiles ◽  
Peeling Test ◽  
Different Types ◽  
Laser Soldering ◽  
Conductive Textile ◽  
High Growth Potential

Experts attest the smart textiles market will have high growth potential during the next ten years. Laser soldering is considered to be a good contacting method because it is a contactless process. For this reason, it is intended to investigate the contacting process of printed circuit boards (PCB) to isolated conductive textile strips by means of a ytterbium-doped fiber laser (1064 nm). During the investigation, the copper strands in the textile tape were stripped by the laser and soldered to the PCB without any transport of the textile. Therefore, we investigated different sets of parameters by means of a design of experiment (DoE) for different types of solder pastes. Finally, the joinings were electrically analyzed using a contact resistance test, optically with a REM examination, and mechanically using a peeling test.

scholarly journals Morphology and acoustic artefacts of copper deposits electroplated using megasonic assisted agitation

Circuit World ◽  
2016 ◽  
Vol 42 (3) ◽  
pp. 127-140 ◽  
Author(s):  
Thomas D.A. Jones ◽  
David Flynn ◽  
Marc P.Y. Desmulliez ◽  
Dennis Price ◽  
Matthew Beadel ◽  
...  
Keyword(s):  
Acoustic Waves ◽  
Printed Circuit Boards ◽  
Surface Acoustic Waves ◽  
Electrolyte Solutions ◽  
Acoustic Power ◽  
Circuit Boards ◽  
Content Type ◽  
Measuring Surface ◽  
Micro Bubble ◽  
The Impact

Purpose This study aims to understand the influence of megasonic (MS)-assisted agitation on printed circuit boards (PCBs) electroplated using copper (Cu) electrolyte solutions to improve plating efficiencies through enhanced ion transportation. Design/methodology/approach The impact of MS-assisted agitation on topographical properties of the electroplated surfaces was studied through a design of experiments by measuring surface roughness, which is characterised by values of the parameter Ra as measured by white light phase shifting interferometry and high-resolution scanning electron microscopy. Findings An increase in Ra from 400 to 760 nm after plating was recorded for an increase in acoustic power from 45 to 450 W. Roughening increased because of micro-bubble cavitation energy and was supported through direct imaging of the cavitation. Current thieving effect by the MS transducer induced low currents, leading to large Cu grain frosting and reduction in the board quality. Current thieving was negated in plating trials through specific placement of transducer. Wavy electroplated surfaces, due to surface acoustic waves, were also observed to reduce the uniformity of the deposit. Research limitations/implications The formation of unstable transient cavitation and variation of the topology of the Cu surface are unwanted phenomena. Further plating studies using MS agitation are needed, along with fundamental simulations, to determine how the effects can be reduced or prevented. Practical implications This study can help identify manufacturing settings required for high-quality MS-assisted plating and promote areas for further investigation, leading to the development of an MS plating manufacturing technique. Originality/value This study quantifies the topographical changes to a PCB surface in response to MS agitation and evidence for deposited Cu artefacts due to acoustic effects.

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