Electrical and electronics applications

Electrical applications have long been the domain of thermosets. However, thermoplastic blends and alloys possess clear advantages  

Typically PPE/PS, PC/ABS, and PBT/PC blends are used in electrical applications such as lighting, meters, ballasts, electrical boxes, safety yokes on power lines, smoke and carbon monoxide detectors, etc. Important material properties for these applications include good tensile strength creep resistance high HDT 

Polymer blends for packaging and materials handling of electrical components would require a degree of electrical conductivity to provide for static charge dissipation. This can be achieved either by a conductive additive, such as carbon black, carbon nano-tubes or metal fibers, or via blending with a conductive polymer like polyanUine. Blending of the latter is necessary to provide flow 

Flammability ratings are required for certain electrical applications, such as the internal components of electronic devices. Flame retardancy can be imparted by blending an inherently flame retardant polymer such as PVC with one providing improved processability, such as a styrenic. Primary application areas are in business machine and appliance housings. 

Good processability may be required in fabrication operations such as injection or blow molding, extrusion and thermoforming. High mechanical performance may not always be needed in non-load bearing simations. Examples of PAB s for various electrical applications are shown in Table 13.11. 

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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. 

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

The principal use of gold is as a very thin coating about 0-05 /xm thick for electrical and electronic applications. Because of the thinness of gold electrodeposits, porosity must be very carefully controlled since seepage of corrosion products from substrate or undercoat exposed at these pores can have serious adverse effects on both appearance and electrical properties of the composite. The porosity can vary with the thickness of the deposit (Fig. 13.1), and with the type of plating bath and with its method of operation (Fig. 13.2), and the phenomenon has been extensively studied by Clarke and many other workers. 

Copper is plated on printed circuit boards to provide electrical conductors and for a variety of other electrical and electronic applications. ... 

Glass-filled, toughened polyethylene terephthalate) (PET) resins can be readily moulded into highly impact-resistant structural parts for appliances and automotive components. The PET-based compounds are also suitable for construction (e.g. as structural members), equipment housings (e.g. printer and copier parts), agricultural applications (e.g. mower and tractor engine covers), materials handling (e.g. pallets and trays), furniture (e.g. office chair bases), as well as electrical and electronic applications. 

The consumption of LCPs varies from country to country and depends on the source. Global consumption can be estimated between 20000 and 30000 tonnes. LCPs are mainly used in electrical and electronics applications and, to a lesser degree, in industry and automotive. The following markets shares are quoted ... 

Thin-walled (approximately 0.010-0.040 in., or 0.25-1.0 mm) tubing is usually selected by continuous service temperature, which may range from 90°C (194°F) for some PVC tubing up to 250°C (482°F) for tubing made from PTFE. The main use of thin shrink tubing is in electrical and electronic applications. 

TPX is a good insulating material. It is used in electric and electronic applications. 

Electrical Properties. Polysulfones offer excellent electrical insulative capabilities and other electrical properties as can be seen from the data in Table 7. The resins exhibit low dielectric constants and dissipation factors even in the GHz (microwave) frequency range. This performance is retained over a wide temperature range and has permitted applications such as printed wiring board substrates, electronic connectors, lighting sockets, business machine components, and automotive fuse housings, to name a few. The desirable electrical properties along with the inherent flame retardancy of polysulfones make these polymers prime candidates in many high temperature electrical and electronic applications. 

Most resistors for electrical and electronic applications are required to be ohmic and to have small temperature coefficients of resistance. The major requirement in electronics is for resistors in the range 103—108 Q, while materials with suitable electrical properties usually have resistivities less than 10-6 Qm. Fabrication of a 105Q resistor of length 110mm from a material with a resistivity of 10-6 Qm requires a cross-sectional area of 10-12 m2, i.e. a strip 1 /mi thick and 1 /tm wide, for example. This is not a technical impossibility, but other more economic routes to resistor manufacture have been established based on the following two principles. 

In addition to joining, adhesives in electrical applications may be required to conduct heat, conduct or isolate electricity, provide shock mounting, seal, protect substrates, etc. Thermal and chemical resistance, weathering, and structural compatibility must also be considered in diverse electrical and electronic applications. Of course, the choice of adhesive will also be governed by application methods, cure temperature, processing speed, and overall economic cost. 

Cycloaliphatic and heterocyclic epoxy have better weather resistance and less tendency to yellow and chalk than do aromatic epoxy resins. These resins possess excellent electrical properties and are often used in electrical and electronic applications. They are generally formulated into casting and filament winding compounds. 

Test Method for Impact Strength of Adhesive Bonds Test Method for Tensile Properties of Adhesive Bonds Test Methods for Pressure Sensitive Adhesive Coated Tapes Used for Electrical and Electronic Applications... 

About one half of the PTFE resin produced is used in electrical and electronic applications [10] with major use for insulation of hookup wire for military and aerospace electronic equipment. PTFE is also used as insulation for airframe and computer wires, as spaghetti tubing, and in electronic components. PTFE tape is used for wrapping coaxial cables. An example of an application of PTFE wrap tape is shown in Eigure 4.12. 

The absence of polar groups along the polymer chain results in a low dielectric constant with respect to other common engineering thermoplastics. This represents a clear advantage in electric and electronic applications, but also has useful consequences in processing operations where a low moisture adsorption leads to short drying cycles (or none). 

In recent years gold has found increased markets in electrical and electronic applications, but these account for <5% of annual consumption. 

The principal consumption of PGE is as a catalyst, especially the use of platinum, or the more favored palladium because of its superior high-temperature performance, in catalytic converters in motor vehicles. Among the diverse other chief uses are electrical and electronic applications, jewelry, fabrication of laboratory equipment, and dental repairs. 

The main representatives of this group are steatite, cordierite and forsterite ceramics. The prevailing crystalline phases in these materials are the minerals enstatite, cordierite and forsterite, which are also responsible for the main properties. All the materials find use in electrical and electronic applications where their insulating ability, as well as further specific properties are exploited. These are ... 

Fig. 7 shows the content of low molecular weight siloxanes in the silicone polymer. As shown in the figure, almost all of the low molecular weight siloxanes can be removed from the original polymer through refining process. Nowadays, refined polymers are used for RTV rubber for electrical and electronic applications. Refined silicone sealants are used as clean room sealants in the field related to semiconductor manufacturing. 

Electron transport properties of metal oxides nanoparticles are very important for electrical and electronic applications as well as for understanding the unique one-dimensional carrier transport mechanism. It has been noticed that the diameter of metal oxides nanoparticles, surface conditions, crystal structure and its quality i.e., chemical composition, crystallographic orientation along the film axis etc are important parameters that influence the electron transport mechanism. It is found that conductance of a nano-structure strongly depends on their crystalline structure. For example, in the case of perfect crystalline Si nanowires having four atoms per unit cell, generally three conductance channels are found [51], One-or two-atom defect, either by addition or removal of one or two atoms may disrupt the number of such conductance channel and may cause variation in the conductance. It has been observed that change in the surface conditions of the nanowires can cause remarkable... 

The third market fraction is the traditional SLI battery application field which is under development due to an increasing demand for electrical and electronic applications in cars, like air conditioning systems and altemo-starters. To compensate the related demand for DC power, major car manufacturers have decided to increase the voltage of the battery unit from 12 volts to 42 volts. 

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