Electronic circuit boards

Applications. The applications sought for these polymers include composites, stmctural plastics, electronics/circuit boards, aircraft/spacecraft coatings, seals, dental and medical prosthetics, and laser window adhesives. However, other than the early commercialization by Du Pont of the NR-150 B material, Httie development has occurred. These polymers are quite expensive ( 110 to 2200 per kg for monomers alone). 

Diallyl terephthalate [1026-92-2] is utilized less, but lenses made of copolymers with triaHyl cyanurate and methacrylates have been suggested (62). Diallyl tetrabromophthalate and tetrachlorophthalate polymers have been proposed for electronic circuit boards of low flammabiUty (63). They are uv-curable and solder-resistant. Copolymers with unsaturated polyester, vinyl acetate and DAP have been studied (64). 

Fig. 17. Schematic of a z-axis conductive PSA bonding elements in an electronic circuit board.

Uses Manufacture of fluorocarbon refrigerants, fluorocarbon plastics, and propellants solvent for natural products analytical chemistry cleansing agent soil fumigant insecticides preparation of chlorodifluoromethane, methyl fluoride, salicylaldehyde cleaning electronic circuit boards in fire extinguishers. 

F i g u re 4.1 7 An electronic circuit board being given a protective polysiloxane coating. The photograph was generously provided by the Dow Corning Corporation of Midland, MI. 

The procedural controls applicable for the preventive maintenance and repair of the hardware provide a mechanism for anticipating problems and, as a consequence, possible loss of data. Modem hardware usually requires minimum maintenance because electronic circuit boards, for example, are usually easily replaced and cleaning may be limited to dust removal. Diagnostic software is usually available from the supplier to check the performance of the computer system and to isolate defective integrated circuits. Maintenance procedures should be included in the organization s standard operating procedures. The availability of spare parts and access to qualified service personnel are important for the smooth operation of the maintenance program. 

Second behind packaging in the United States is the use of polymers in fiber and fiberfill applications that encompass the apparel, sports equipment, building and construction, electronic, furniture and furnishings, and industrial/machinery markets. In 1998, 4.8 million metric t of manufactured fiber was produced for use in traditional consumer products such as apparel, carpets, upholstered furniture, and bedding as well as in high-tech applications such as composite materials, medical devices, and electronic circuit boards (17). Key fiber types include polyester, nylon, olefin,... 

Spacecraft equipment panels supports, electronic circuit boards, optical equipment, antenna and support structures acoustic fatigue, malfunction, vibration control... 

Self-healing materials should have many applications. The U.S. Air Force, which partially funded the research at UIUC, is interested in using the materials in tanks that hold gases and liquids under pressure. The current materials used for these tanks are subject to microcracks that eventually grow, causing the tanks to leak. Self-healing materials would also be valuable in situations where repair is impossible or impractical, such as electronic circuit boards, components of deep space probes, and implanted medical devices. ... 

Tetrabromobisphenol A, a brominated analog of Bisphenol A, is an important nonflammable additive in the production of synthetic resins, polycarbonates and plastics, used in the manufacture of computer and electronic housings, laminated electronic circuit boards, carpets, upholstery and many other consumer goods . Tetrabromobisphenol A is used as a flame retardant to a much larger extent than its chlorinated analog tetrachloro-bisphenol... 

MAJOR PRODUCT APPLICATIONS paints (non-skid coatings, textured paints, flatting), chemical carrier, cleaning and polishing liquids, soaps, tooth polishing pastes and powders, cleaning electronic circuit boards... 

HCFC-225aa, HCFC-225ca and HCFC-225cb are solvents which are useful for the cleaning of electronic circuit boards and can provide a temporary replacement for CFC-113 which has been extensively used for this application. The 225 isomers are readily prepared by the addition of HCFC-21 to TFE using an AlC F catalyst... 

In the aerospace industry, resinous polymers encompass a wide variety of hardware applications for aircraft, missiles, and space structures. In aircraft, resins are used as a matrix material for primary (flight-dependent) and secondary fiber-reinforced composite (FRC) structures, adhesives for the bonding of metal and composite hardware components, electronic circuit board materials, sealants, and radomes. Missile applications include equipment sections, motor cases, nose cones, cartjon-carbon composites for engine nozzles, adhesive bonding, and electronics. As the exploration of outer space intensifies, applications will become even more exotic. FRC will be used to construct telescopes, antennas, satellites, and eventually housing and other platform structures where special properties such as weight, stiffness, and dimensional stability are important. 

The other CFC of major environmental concern was CFC-113, C2F3CI3. It was used extensively for cleaning the glue, grease and solder residues from electronic circuit boards after their fabrication, up to 2 kg m . 

The basic phenomenon agglomeration applies to all situations where at least two solid particles are joined together under the action of a binding mechanism (see Section 5.1.1). Thereby, one type of the particulate solid may be very small and the other extremely large. Such a condition exists, for example, if a single particle or, in other cases, a small, well controlled number of particles, which typically are or may be micro-or nanometer-sized, adhere(s) to a surface. The result of this manner of agglomeration is either detrimental if the particles are contaminants on, for example, electronic circuit boards or chips [B.34], or individual particle deposition is highly desirable if it is accomplished in a controlled fashion to achieve special material properties (see Section... 

Figure 5. Fuel Cell Monitoring and Control Electronics Circuit Board Mounted on Scooter Drive Unit...

Surfactants are often used for cleaning objects as well as for industrial waste water treatment. Thus, high-molecular fluorocarbon surfactants in a perfluorinated carrier liquid were used as liquid rinses for the decontamination of model electronic circuit boards [324]. A three log reduction in contamination was obtained in 1 hour, and the circuit boards were still functional... 

To create a work of art, a sculptor can either chisel away a large block of stone or cement together smaller building blocks. Similarly nanoscale materials can be made by either a top-down or a bottom-up approach. Microlithography to make electronic circuit boards is an example of top-down construction. Construction of nanoscale materials bottom up by assembly of molecules and nanoparticles is just now... 

Thermal testing Voids or disbands in both metallic and nonmetallic materials, location of hot or cold spots in thermally active assemblies Laminated structures, honeycomb, and electronic circuit boards Produces a thermal image that is easily interpreted Difficult to control surface emissivity poor discrimination... 

Incorporating fillers or reinforcing agents is another means of improving polymer properties. High particulate loadings improve the dimensional stability of electronic circuit boards so that the thermal expansion is greatly reduced. Particulate fillers (talc, mica, silica, clay, etc.) are used... 

Chem. Descrip. Silicone resin sol n. in xylene, IPA, butyl alcohol Uses Dry-tilm release coating tor molding ot plastics or rubber adherent coating tor conveyors, chutes, and handling equip, used in rubber, plastics, and adhesives mtg. release agent tor electronic circuit board mfg. particle binder... 

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