scholarly journals The influence of novel organic gold complex on photoresist layers of printed circuit boards

10.30544/73 ◽  
2015 ◽  
Vol 21 (4) ◽  
pp. 269-276
Author(s):  
Silvana Dimitrijević ◽  
Zoran Stević ◽  
Mirjana Rajčić-Vujasinović ◽  
Vesna Grekulović ◽  
Stevan Dimitrijević ◽  
...  
Keyword(s):  
Printed Circuit Boards ◽  
Ph Value ◽  
Operating Conditions ◽  
Gold Complex ◽  
Gold Concentration ◽  
Circuit Boards ◽  
Optimal Operating ◽  
Gold Complexes ◽  
Printed Circuit ◽  
Ph Values

The goal of this paper was to study the influence of organic gold complex based on mercaptotriazole on photoresist layers used in manufacturing of printed circuit boards (PCBs). Investigations were performed by immersion the previously prepared boards in electrolytes with different pH values (pH=2, 4, 7, 9 and 12) at gold concentration of 2.5 g/dm3 and in gold complexes with different gold concentrations (1.5; 2.0; 2.5; 3.0 and 3.5 g/dm3) at pH value of pH=9. Investigations showed that photoresist layers on boards are the most resistant at optimal operating conditions, pH=9 and concentration of gold of 2.5 g/dm3.

Development of a Technique to Measure Deliquescent Relative Humidity of Particulate Contaminants and Determination of the Operating Relative Humidity of a Data Center

2019 ◽  
Author(s):  
Jimil M. Shah ◽  
Roshan Anand ◽  
Satyam Saini ◽  
Rawhan Cyriac ◽  
Dereje Agonafer ◽  
...  
Keyword(s):  
Particulate Matter ◽  
Relative Humidity ◽  
Data Center ◽  
Printed Circuit Boards ◽  
Data Centers ◽  
Operating Conditions ◽  
Test Method ◽  
Dust Particles ◽  
Circuit Boards ◽  
Printed Circuit

Abstract A remarkable amount of data center energy is consumed in eliminating the heat generated by the IT equipment to maintain and ensure safe operating conditions and optimum performance. The installation of Airside Economizers, while very energy efficient, bears the risk of particulate contamination in data centers, hence, deteriorating the reliability of IT equipment. When RH in data centers exceeds the deliquescent relative humidity (DRH) of salts or accumulated particulate matter, it absorbs moisture, becomes wet and subsequently leads to electrical short circuiting because of degraded surface insulation resistance between the closely spaced features on printed circuit boards. Another concern with this type of failure is the absence of evidence that hinders the process of evaluation and rectification. Therefore, it is imperative to develop a practical test method to determine the DRH value of the accumulated particulate matter found on PCBs (Printed Circuit Boards). This research is a first attempt to develop an experimental technique to measure the DRH of dust particles by logging the leakage current versus RH% (Relative Humidity percentage) for the particulate matter dispensed on an interdigitated comb coupon. To validate this methodology, the DRH of pure salts like MgCl2, NH4NO3 and NaCl is determined and their results are then compared with their published values. This methodology was therefore implemented to help lay a modus operandi of establishing the limiting value or an effective relative humidity envelope to be maintained at a real-world data center facility situated in Dallas industrial area for its continuous and reliable operation.

scholarly journals Selective Recovery Of Copper From Solutions After Bioleaching Electronic Waste

2015 ◽  
Vol 14 (1) ◽  
pp. 32-37 ◽  
Author(s):  
Joanna Willner ◽  
Agnieszka Fornalczyk ◽  
Mariola Saternus
Keyword(s):  
Aqueous Phase ◽  
Printed Circuit Boards ◽  
Ph Value ◽  
Electronic Waste ◽  
Selective Extraction ◽  
Circuit Boards ◽  
Extractant Concentration ◽  
Simultaneous Effect ◽  
Printed Circuit ◽  
Initial Ph

Abstract Research on selective extraction of copper from solution after bioleaching grounded printed circuit boards (PCBs) using LIX 860N-IC were conducted. The effect of LIX 860N-IC concentration, phase ratio and influence of initial pH value of aqueous phase on the extraction of copper and iron was examined. It was found that the extraction rate of copper increases with the LIX 860N-IC concentration. Best results of Cu extraction (98 %) were achieved with extractant concentration of 5 % and pH 1.9. Higher pH value of aqueous phase (pH=2.4) is conducive to the simultaneous effect of Fe co-extraction.

Thermal Management of Heat Generating Devices in Close Proximity on Printed Circuit Boards

2005 ◽  
Author(s):  
Jared Harvest ◽  
Amy S. Fleischer ◽  
Randy D. Weinstein
Keyword(s):  
Thermal Management ◽  
Printed Circuit Boards ◽  
Separation Distance ◽  
Circuit Board ◽  
Circuit Boards ◽  
Optimal Operating ◽  
Printed Circuit ◽  
Close Proximity ◽  
Board Material ◽  
Dynamics Models

This study uses experimentally validated computational fluid dynamics models to predict the behavior of the localized thermal interactions between adjacent components on vertically orientated circuit boards in natural convection. Using the developed models, the effects of power density, component proximity, component geometry, circuit board material, board packing density and board separation distance on the maintenance of optimal operating temperatures for all components are investigated. The device separation distance beyond which the components no longer thermally influence each other is identified and the influence of various parameters on this distance is studied. The parametric study is designed using Design of Experiments methodology to best interpret the interaction between parameters and can easily be applied to other packaging situations to allow designers to optimally place components on a circuit board in close proximity to minimize negative thermal interactions.

Recovery of Copper from Bio-Leaching Solutions of Waste Printed Circuit Boards Waste by Solvent Extraction Using RE609 and N902

2010 ◽  
Vol 113-116 ◽  
pp. 2228-2231 ◽  
Author(s):  
Cheng Long Zhang ◽  
Wang Dong Fang ◽  
Yu Chen ◽  
Jing Wei Wang ◽  
Jian Feng Bai
Keyword(s):  
Solvent Extraction ◽  
Printed Circuit Boards ◽  
Ph Value ◽  
Copper Extraction ◽  
Equilibration Time ◽  
Circuit Boards ◽  
Extractant Concentration ◽  
H2so4 Concentration ◽  
Printed Circuit ◽  
Waste Printed Circuit Boards

According to the properties of bioleaching solutions of printed circuit boards (PCBs), copper(Ⅱ) in the leaching solution were recovery by solvent extraction with N902 and RE609. The influence of equilibration time，extractant concentration，O/A ratios，pH value on copper(Ⅱ) extraction and sulphuric acid concentration on copper(Ⅱ) stripping had been studied. Extraction of copper increased with increasing extractant concentration with both the extractants. More than 97.45% of copper can be extracted from a typical bioleaching solution of PCBs after copper extraction was carried out using 10% N902 diluted in kerosene at O/A ratio of 1:1, while 97.14% of copper can be extracted using 20% RE609 diluted in kerosene at O/A ratio of 1:1. The stripping of copper loaded N902 and RE609 increased with increasing H2SO4 concentration, but stripping of the latter was lower than the former.More than 93.57% and 90.29%of copper can be stripped from the loaded N902 and RE609 stripped at 1:1 phase ratio with 1.8 M H2SO4 in a single stage.

Use Condition Characterization of Package Components

2011 ◽  
Author(s):  
Leigh Wojewoda ◽  
Dhanya Athreya ◽  
Michael J. Hill
Keyword(s):  
Printed Circuit Boards ◽  
Operating Conditions ◽  
Metal Composite ◽  
Electronic Packages ◽  
Circuit Boards ◽  
Composite Component ◽  
Electrical Parameters ◽  
Analysis And Design ◽  
Printed Circuit

Discrete components, such as capacitors and inductors, play an important role in the analysis and design of electronic packages and printed circuit boards. Although the electrical parameters of discrete components are described by manufacturers, the component performance at product operating conditions can vary drastically from the manufacturer’s specification. Accurate characterization of discrete package components at operating conditions is essential to understand product operation. This paper will introduce a method to characterize discrete capacitors and inductors while applying multiple operating conditions simultaneously. Several inductor options will be evaluated, including a newly introduced metal composite component.

Slit Effect of Common Ground Patterns in Affecting Cross-Talk Noise between Two Parallel Signal Traces on Printed Circuit Boards

2008 ◽  
Vol 128 (11) ◽  
pp. 657-662 ◽  
Author(s):  
Tsuyoshi Maeno ◽  
Yukihiko Sakurai ◽  
Takanori Unou ◽  
Kouji Ichikawa ◽  
Osamu Fujiwara
Keyword(s):  
Cross Talk ◽  
Printed Circuit Boards ◽  
Common Ground ◽  
Circuit Boards ◽  
Printed Circuit
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