scholarly journals Characterization of Printed Circuit Boards for Metal and Energy Recovery after Milling and Mechanical Separation

Materials ◽  
2014 ◽  
Vol 7 (6) ◽  
pp. 4555-4566 ◽  
Author(s):  
Waldir Bizzo ◽  
Renata Figueiredo ◽  
Valdelis de Andrade
Keyword(s):  
Energy Recovery ◽  
Printed Circuit Boards ◽  
Circuit Boards ◽  
Printed Circuit ◽  
Mechanical Separation

Modular Printed Circuit Boards for Broadband Characterization of Nanoelectronic Quantum Devices

2016 ◽  
Vol 65 (8) ◽  
pp. 1827-1835 ◽  
Author(s):  
Marco Lorenzo Valerio Tagliaferri ◽  
Alessandro Crippa ◽  
Simone Cocco ◽  
Marco De Michielis ◽  
Marco Fanciulli ◽  
...  
Keyword(s):  
Printed Circuit Boards ◽  
Circuit Boards ◽  
Quantum Devices ◽  
Printed Circuit

Time-Dependent Rheological Behavior of Fluids For Electronics Packaging

2005 ◽  
Vol 127 (4) ◽  
pp. 370-374 ◽  
Author(s):  
X. B. Chen
Keyword(s):  
Rheological Behavior ◽  
Printed Circuit Boards ◽  
Flow Behavior ◽  
Electronics Packaging ◽  
Time Dependent ◽  
Circuit Boards ◽  
Printed Circuit ◽  
Fluid Behavior ◽  
Surface Mounting

In electronics packaging, one of the key processes is dispensing fluid materials, such as adhesive, epoxy, encapsulant, onto substrates or printed circuit boards for the purpose of surface mounting or encapsulation. In order to precisely control the dispensing process, the understanding and characterization of the flow behavior of the fluid being dispensed is very important, as the behavior can have a significant influence on the dispensing process. However, this task has proven to be very challenging due to the fact that the fluids for electronics packaging usually exhibit the time-dependent rheological behavior, which has not been well defined in literature. In the paper a study on the characterization of the time-dependent rheological behavior of the fluids for electronics packaging is presented. In particular, a model is developed based on structural theory and then applied to the characterization of the decay and recovery of fluid behavior, which happen in the dispensing process due to the interruption of process. Experiments are carried out to verify the effectiveness of the model developed.

scholarly journals Experimental and numerical characterization of thin woven composites used in printed circuit boards for high frequency applications

2018 ◽  
Vol 193 ◽  
pp. 140-153 ◽  
Author(s):  
Gautier Girard ◽  
Mohamad Jrad ◽  
Slim Bahi ◽  
Marion Martiny ◽  
Sébastien Mercier ◽  
...  
Keyword(s):  
High Frequency ◽  
Printed Circuit Boards ◽  
Woven Composites ◽  
Circuit Boards ◽  
Printed Circuit ◽  
Numerical Characterization

Printed Circuit Boards Recycling: Characterization of Granulometric Fractions from Shredding Process

2010 ◽  
Vol 636-637 ◽  
pp. 1434-1439 ◽  
Author(s):  
Paula C. Oliveira ◽  
Marta Cabral ◽  
Carlos A. Nogueira ◽  
Fernanda Margarido
Keyword(s):  
Printed Circuit Boards ◽  
Precious Metals ◽  
Chemical Characterization ◽  
Average Diameter ◽  
Ceramic Materials ◽  
Size Reduction ◽  
Circuit Boards ◽  
Printed Circuit ◽  
Minor Elements

In electronic appliances, printed circuit boards (PCB) represent an important component, containing high grade of valuable metals, besides organic resins and some ceramic materials. Copper is the major metal in PBC’s composition (normally higher than 20% w/w) but many other secondary and minor metal elements, including precious metals, are found in PCB’s. Recycling of PCB´s involves firstly the shredding operation, which is crucial in order to liberate particles from different materials, allowing its further processing by other mechanical, physical and chemical technologies. An efficient shredding operation is difficult to achieve due to the high heterogeneity of these wastes involving materials with different mechanical properties and complex assemblies. This paper presents results from laboratorial studies of shredding of PCB’s and the evaluation of size reduction efficiency as well as the chemical characterization of the obtained shredded fractions. Results showed that an efficient size reduction (characteristic average diameter d50=1.0mm) is obtained using two shredding stages of PCB’s, the first one with a grab shredder and the second one with a cutting mill. Chemical analysis of shredded PCB’s indicated that copper is the principal metal present (28%) followed by Sn, Zn, Pb and Al (3-5%) and many other minor elements. The fine fractions were rich in plastic materials while the metals were essentially present in the intermediate fractions (0.3-1.5 mm). These results can lead to guidelines regarding further design of the physical separation steps in the recycling processes.

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