Polyesters printed circuit boards

About half of epoxide resin production is used for surface coating applications, with the rest divided approximately equally between electronic applications (particularly for printed circuit boards and encapsulation), the building sector and miscellaneous uses. In tonnage terms consumption of epoxide-fibre laminates is only about one-tenth that of polyester laminates, but in terms of value it is much greater. 

Epoxide resins reinforced with carbon and Aramid fibres have been used in small boats, where it is claimed that products of equal stiffness and more useable space may be produced with a 40% saving in weight over traditional polyester/ glass fibre composites. Aramid fibre-reinforced epoxide resins have been developed in the United States to replace steel helmets for military purposes. Printed circuit board bases also provide a substantial outlet for epoxide resins. One recent survey indicates that over one-quarter of epoxide resin production in Western Europe is used for this application. The laminates also find some use in chermical engineering plant and in tooling. 

Polymeric substrate materials in use include highly filled phenolic and epoxy resins for rigid printed circuit boards, polyimides and polyesters for circuit substrates as well as for more general applications, special foamed poly(tetrafluoroethylene) polymers and copolymers, foamed composite materials of the latter, special epoxy fiberglass composites, and polyimide support layers for TAB. In addition, epoxies and silicone polymers are used increasingly in applications as encapsulants, as humidity and environmental barriers within packages, and as packaging materials themselves. 

Aromatic Polyesters Engineering thermoplastics prepared by polymerization of aromatic polyol with aromatic dicarboxylic anhydride. They are tough with somewhat low chemical resistance. Processed by injection and blow-molding, extrusion, andftiermoforming. Drying is required. Used in automotive housings and trim, electrical wire j acketing, printed circuit boards, and appliance enclosures. 

Chem. Descrip. Glycerin-1-allylether CAS 123-34-2 EINECS/ELINCS 204-6204 Uses Can be polymerized into polyesters, polyurethanes, polyacetals, and epoxy resins (hydroxyl group) or with acrylates, methacrylates, or styrene (ilyl group) for prod, of PL) rubber and foam printed circuit boards unsat. polyesters used for radiation-resist, coatings copolymers as dispersants for pigments or as corrosion inhibitors Properties Colorless to yish. vise, liq., perceptible odor sol. in water, ethanol, and many org. soivs. dens. 1.07 g/cc vapor pressure 0.004 mbar (20 C) m.p. < C b.p. 245 C (decomp.) flash pt. 135 C pH 7 (5% aq.) 9 /o assay... 

CAS 21645-51-2 EINECS/ELINCS 244-492-7 Uses Flame retardant, smoke suppressanL processing aid, water resist, aid, antistat for wire/cable, elec, insulators, printed circuit boards, potting resins, molded and extruded polyolefins, flooring compds., conveyor belting, fabric coatings, polyester and aciylic pultrusion compds., thermosetting resins (BMC, SMC), PVC, EVA, EPDM, XLPE, EEA, thermoplastic elastomers, silicone rubber, NR, SR, acrylic resins, unsat. polyesters... 

Uses Moisture-resist., protective films for outdoor use, transportation industry, pkg., building laminates, decorative applies. release film for printed circuit boards, thermosetting resins, epoxies, phenolics, polyester, rubber compds. in food-contact coatings Reguiatory FDA 21CFR 175.270 Trade Name Synonyms Tedlar Series [DuPont... 

The adhesives in Table 5 have many industrial applications. For example, EC-3535 B/A has been used to bond aluminum extrusions into auto roofs while EC-3532 B/A has been used to bond vinyl clad wire to printed circuit board. Urethane adhesives have also been us ed to bond polyester molded resin to the steel frame in Corvette auto bodies. 

Electrical Laminates. Printed wiring boards (PWB) or printed circuit boards (PCB) are used in all types of electronic equipment. In noncritical applications such as inexpensive consnmer electronics, these components are made from paper-reinforced phenolic, melamine, or polyester resins. For more critical applications such as high end consnmer electronics, computers, complex telecommunication equipment, etc, higher performance materials are required and epoxy resin based glass fiber laminates fnlfill the requirements at reasonable costs. This application constitntes the single largest volume of epoxies used in structural composites. In 2000, an estimated 200,000 MT of epoxy resins were used globally to manufacture PCB laminates. 

Sheet products made from mineral-filled LC polyesters variants or multilayer copper and LC polyester laminates have been used for thermoforming and electroplating for printed circuit board. 

Polymeric materials are used as the basis of photoresists for making metal patterns on printed circuit boards, and also on the individual integrated circuit devices themselves. The circuit boards are made of various glass-fibre filled epoxides and polyesters, and are usually coated with other polymeric materials to prevent tarnishing and to improve solderability. The devices that are mounted on the completed printed circuit boards may have been manufactured using polymeric photoresists or have plastics such as polypropylene and polyester films in capacitors or epoxide resins in integrated circuits and transistors. The completed boards containing various devices are often then coated in another protective polymer. Finally, electrical connections are made... 

It is noteworthy that the products thus prepared possess remarkable physico-chemieal properties (glass transition point mechanical, electrical, and optical characteristics), as evidenced by exeellent transpareney, good moldability, and high resistance to heat, aging, solvents, and weathering. Furthermore, they are eompatible with many polymers, ineluding polyesters, polyearbonates, polyamides, and polyolefins, and find broad application in the manufactme of optical devices, photo disks, circuit boards for crystalline liquids, printed circuit boards, special electrical and electronic devices, and so on. 

Silicone PSAs find application almost exclusively in tape form. Polyester film is widely used as backing particularly for masked printed circuit boards during plating operations, for electrical insulation and paper splicing tapes. Glass cloth-backed tapes are preferred for... 

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