Image Wavelet Transform for PCB Soldering's Quality Evaluation

2006 ◽  
Vol 113 ◽  
pp. 85-90
Author(s):  
Evaras Zitkevicius ◽  
Romanas Martavicius

An integration degree of modern printed circuit boards (PCB) is continually increasing. One of the important stages in the manufacturing of electronic devices is component soldering onto PCB pads. The soldering process is affected by many factors, which may lead to the formation of undesirable soldering defects. Some kinds of defects including bridge defects are detected visually. In the current article the possibility of bridge defect detection in a multi-pin surface mount component PCB images using wavelet transform is analyzed.

2014 ◽  
Vol 2014 (1) ◽  
pp. 000444-000447 ◽  
Author(s):  
Yoshio Nishimura ◽  
Hirohisa Narahashi ◽  
Shigeo Nakamura ◽  
Tadahiko Yokota

Printed circuit boards manufactured by a semi-additive process are widely used for packaging substrates. Along with increasing demands of downsizing electronic devices with high functionality, packaging substrates installed with semiconductors in such devices are strongly required to be miniaturized with high density of circuit wirings. We report our insulation build-up materials and processes for advanced packages with fine line/space and high reliability. The insulation materials we developed show low coefficient of thermal expansion (CTE), low dielectric loss tangent and good thinner insulation reliability. They can produce fine line and space (FLS) under 10μm pitch by a semi-additive process.


2018 ◽  
Vol 10 (31) ◽  
pp. 3864-3871 ◽  
Author(s):  
B. Bookhagen ◽  
W. Obermaier ◽  
C. Opper ◽  
C. Koeberl ◽  
T. Hofmann ◽  
...  

A comprehensive method for the determination of metals in electronic devices was developed and tested on smartphones.


Minerals ◽  
2021 ◽  
Vol 11 (9) ◽  
pp. 1014
Author(s):  
Pedro Jorge Walburga Keglevich de Buzin ◽  
Weslei Monteiro Ambrós ◽  
Irineu Antônio Schadach de Brum ◽  
Rejane Maria Candiota Tubino ◽  
Carlos Hoffmann Sampaio ◽  
...  

Wastes from old electronic devices represent a significant part of the electronic scrap generated in developing countries, being commonly sold by collectors as low-value material to recycling hubs abroad. Upgrading the quality of this waste type could drive the revenue of recyclers, and thus, boost the recycling market. On this basis, this study investigated the possibility of concentrating metals from old wasted printed circuit boards through a physical separation-based route. Preparation of samples comprised fragmentation, size classification, density, and magnetic separation steps, followed by chemical and macro composition analysis. Cu, Al, Fe, and Sn constituted the major metals encountered in the scraps, including some peak concentrations of Zn, Sb, Pb, Ba, and Mn. Four distinct concentrate products could be obtained after suitable processing: (a) a light fraction composed of plastics and resins; (b) an aluminum concentrate; (c) a magnetic material concentrate, containing mainly iron; (d) a final concentrate containing more than 50% in mass of copper and enriched with nonferrous metals. Preliminary evidence showed that further processes, like the separation of copper wires through drumming, can potentially improve the effectiveness of the proposed processing circuit and should guide future works.


2021 ◽  
Vol 1 (1) ◽  
Author(s):  
Anna HOŁDA ◽  
Aldona KRAWCZYKOWSKA

Technological innovations and increased demand for electronic devices resulted in production of more and more waste with highmetal content. Worldwide, 50 million tons of WEEE (Waste from Electrical and Electronic Equipment) are generated each year. Giventhe metal content present in electrical waste (e-waste), it is considered to be an urban mine and, if properly treated, can serve as analternative secondary source of metals. Waste printed circuit boards (WPCBs) that constitute approx. 3-5% of WEEE by weight areof particular importance. They contain, on average, 30-40% of metals by weight, with higher purity than in minerals. With environmental and economic benefits in mind, increasing attention is being paid to the development of processes to recover metals and othervaluable materials from WPCBs. The research presented in the article aimed at assessing the usefulness of the biotechnological methodfor leaching of selected metals from e-waste. The results indicate that it is possible to mobilize metals from WPCBs using microorganisms such as Acidithiobacillus ferroxidans bacteria 


2021 ◽  
Vol 18 (4) ◽  
pp. 4411-4428
Author(s):  
Venkat Anil Adibhatla ◽  
◽  
Huan-Chuang Chih ◽  
Chi-Chang Hsu ◽  
Joseph Cheng ◽  
...  

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