Soldering resistance

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). 

Films have been used for insulating electric motors, in capacitors requiring a heat resistance not met by conventional polyester and polycarbonate dielectrics and as a soldering-resistant base for flexible printed circuits. 

Solder masks (solder resists) are protective polymer coatings used on printed circuit boards (PCB s) to prevent solder bridging between conductors during soldering (1-3). The selective application of the solder mask limits the amount of conductor area in contact with the molten solder, minimizing solder usage and slowing the rate of conductor metal contamination in the solder pot. 

Solder resist materials, usable in electrical and electronic field, based on po-ly(ester-imide)s made from 1,2,3,4-butanetetracarboxylic acid and p-aminobe-zoic acid or ethanolamine have been patent protected. UV sensitivity was obtained by using fumaric or p-phenylendiacrylic acid [179]. In another patent cinnamic acid [180] is used for a temperature resistant solder resist formulation. UV-curable foils made from poly(ester-imide)s containing a benzophenonetet-racarboxylic diimide are known [181]. 

Curezol . [Air Prods. Paciflc Anchor Anchor UK] Imidazoles epoxy curing agent for a esives, composites, filament winding, solder-resistant inks, potting compds., insulating powds., transfer molding powds. accelerator for dicyandiamide and anhydrides. 

Spread or slump Observe three dots dispensed (0.65 mm diameter and 0.25 mm thick) cured and uncured. Measure uncured dots after 70 minutes <10% (5.6) Average of 1.8 0.2 mm dots on FR4 epoxy with solder resist. Check after 3 minutes uncured and cured. 

A solder resistant high-temperature composition that does not suffer from this drawback has been developed. The blend is composed of poly-(arylene ether) (PAE), PPS, and GFs. The PAE has an intrinsic viscosity (IV) less than or equal to about 0.15 dlg as determined in chloroform at 25°C. The use of the low IV PAE permits improved blending, which leads to improved high-temperature properties. Homopolymers of PAE are those containing 2,6-dimethylphenylene ether units. Suitable copolymers include random copolymers containing, for example, 2,6-dimethylphenylene ether units. In combination with 2,3,6-trimethyl-l,4-phenylene ether units or alternatively, copolymers derived from the copolymerization of 2,6-dimethylphenol with 2,3,6-trimethylphenol. Partially crosslinked PPS, as well as mixtures of branched and linear PPS, may be used in the high-temperature compositions. 

The addition of 4-aminophenol to compositions used commonly for poly-(ester)s allows the production of poly(ester amide)s. For example, a mixture of 2,6-naphthalene dicarboxylic acid, TPA, BP, HBA, and 4-aminophenol is condensed in the presence of acid anhydride. Such materials exhibit good soldering resistance so that they can be utilized as an electric or electronic material such as electric connectors, sockets for integrated circuits, etc. 

Uses Epoxy tor inks, solder resists and coatings (metal, paper, wood) Features Otters high heat resist. 

Chem. Descrip. Epoxy novolac acrylate in 33% monomer blend Uses Epoxy-acrylic providing heat and solv. resist, to solder resists, marking inks, adhesion on metalized substrates, low shrinkage coatings, heat-resist. applies. 

Applications Soldering Resistance Continued Usage Stiffness Damping Properties Low CTE Chemical Resistance High Flowability low Mold Shrinkage... 

Inui, Y. Kojima, T. Green-colored resin composition for solder resist and printed circuit board using it. Jpn. Kokai Tokkyo Koho JP 2004133140, 2004 Chem. Abstr. 2064,140, 365663. 

A liquid-crystalline polyester resin composition is designed by incorporating a liquid-crystalline polyester obtained by polymerizing monomers of an aromatic hydroxycarboxylic acid in the presence of an imidazole compound. The composition also includes a mica (50-100 phr) having a volume average particle diameter of 40 pm or less and a specific surface area of 6 m /g or less. The liquid-crystalline polyester resin composition has melt fluidity sufficient to be molded into a connector having an ultra-thin wall section. The coimector, thus molded, has sufficiently suppressed warp and sufficient soldering resistance [171]. 

Blends of PAEK and PEI can offer increased Tg, good chemical resistance at the lower PEI levels and reduced cost relative to pure PAEK. In particular PEI can be used to build the heat distortion temperature (HDT) of PAEK. Such blends find uses where PAEK-like performance is required in combination with an improved HDT. There are also applications in which the PEI is used above its Tg as a melt adhesive. For example, laminates of copper foil and PEEK/ PEI blend films can be produced in which the copper adheres to the hot, amorphous blend which subsequently crystallises to produce a chemical and solder-resistant structure. Mitsubishi has produced flexible printed circuit boards based on this concept [9]. 

Mobile phone microphone spacer - film Ole Wolff Seokang Solder resistance - replaced PET... 

Micro connector - PEEK + glass VP Plast Solder resistance, micro-overmoulding with PEEK... 

Between conformal coatings and the surfaces they are protecting On, in, or under the solder resist... 

Enhancing the planarity of solder resist on the snrface of filled throngh holes and the planarity of core layer for SBU PWBs... 

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