Electronic and electrical materials

Various industries make efforts to introduce static control to workplace, products and packaging. As many as 10% of the failures of electronic equipment are related to static electricity. To control static electricity in the work place, many products should be conductive (coatings, mats, bench tops, etc.). Packaging has been developed using conductive fillers. This creates new opportunities for manufacturers of products and fillers. 

Z-axis adhesives are a unique class of new products. These adhesives contain conductive particles, which due to their orientation, conduct electricity across their thickness but are non-conductive along their length and width. Several circuit lines can be connected through the same strip of Z-axis adhesive with no current flow between circuit lines. 

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Drobny JG (2012) Polymers for electricity and electronics- materials, properties, and applications. Wiley-VCH, Hoboken. ISBN ISBN-10 0-470-45553-5... 

Advanced Electrical and Electronics Materials Process and Applications... 

Sulfur hexafluoride [2551-62-4] 6 molecular weight 146.07, is a colorless, odorless, tasteless gas. It is not flammable and not particularly reactive. Its high chemical stabiUty and excellent electrical characteristics have led to widespread use in various kinds of electrical and electronic equipment such as circuit breakers, capacitors, transformers, microwave components, etc (see Electronic materials). Other properties of the gas have led to limited usage in a variety of unique appHcations ranging from medical appHcations to space research. 

Electrical and Electronic Applications. Silver neodecanoate [62804-19-7] has been used in the preparation of a capacitor-end termination composition (110), lead and stannous neodecanoate have been used in circuit-board fabrication (111), and stannous neodecanoate has been used to form patterned semiconductive tin oxide films (112). The silver salt has also been used in the preparation of ceramic superconductors (113). Neodecanoate salts of barium, copper, yttrium, and europium have been used to prepare superconducting films and patterned thin-fHm superconductors. To prepare these materials, the metal salts are deposited on a substrate, then decomposed by heat to give the thin film (114—116) or by a focused beam (electron, ion, or laser) to give the patterned thin film (117,118). The resulting films exhibit superconductivity above Hquid nitrogen temperatures. 

In the broad range of ceramic materials that are used for electrical and electronic apphcations, each category of material exhibits unique property characteristics which directiy reflect composition, processing, and microstmcture. Detailed treatment is given primarily to those property characteristics relating to insulation behavior and electrical conduction processes. Further details concerning the more specialized electrical behavior in ceramic materials, eg, polarization, dielectric, ferroelectric, piezoelectric, electrooptic, and magnetic phenomena, are covered in References 1—9. 

Whilst plastics materials have been associated with electrical and electronic applications since the early days of the electrical industry, developments over the... 

A number of areas in which plastics are used in electrical and electronic design have been covered there are many more. Examples include fiber optics, computer hardware and software, radomes for radar transmitters, sound transmitters, and appliances. Reviewed were the basic use and behavior for plastics as an insulator or as a dielectric material and applying design parameters. The effect of field intensity, frequency, environmental effects, temperature, and time were reviewed as part of the design process. Several special applications for plastics based on intrinsic properties of plastics materials were also reviewed. 

Synthetic polymers are best known for their insulating dielectric properties which have been exploited for numerous applications in both the electrical and electronic industries. It was found recently that some polymers can also be rendered conductive by an appropriate treatment, thus opening the way to a new field of applications of these materials (2, 3). Usually, electrical conductivity is obtained by doping a neutral polymer, rich in unsaturation, with donor or acceptor molecules. These polymers are rather difficult to synthesize, which makes them very expensive besides they are often sensitive to environmental agents, like oxygen or humidity, thus restricting their practical use to oxygen-free systems. 

By a strict definition, these electrical and electronic wastes are hazardous. Fluorescent lamps contain mercury, and almost all fluorescents fail the U.S. Environmental Protection Agency (U.S. EPA) toxicity test for hazardous wastes. Fluorescent lamp ballasts manufactured in the mid-1980s contain polychorinated biphenyls (PCBs), a carcinogen most of these ballasts are still in service. Batteries can contain any of a number of hazardous materials, including cadmium (nickel-cadmium... 

All electrical and electronic wastes may be found to harbor components containing particularly hazardous substances. It is essential that these be removed (stripping of hazardous materials). Below are some examples of such components. Batteries and accumulators notably include the following ... 

For this purpose, the WEEE Directive has been complemented with an additional directive that limits the use of certain pollutants in these products. The EC Directive 2002/95/EC on the Restriction of the use of certain Hazardous Substances in electrical and electronic equipment (RoHS Directive) ([7], recast 2011 [9]) restricts the use of the six harmful substances/substance families lead, mercury, hexavalent chromium, polybrominated biphenyls (PBB), and polybrominated diphenyl ethers (PBDE) to 0.1% and cadmium to 0.01% w/w per homogenous material in equipment and components, but with several exemptions for a wide range of applications (Annex III and IV). 

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