FR stands for flame retardant, and denotes that safety of flammability of FR4 is in compliance with the standard UL94V-0.
The FR4 epoxy laminate has a smooth surface, no air bubbles, no pits and wrinkles, but allows for other defects that do not affect the use, such as: scratches, indentations, stains and small spots. The edges should be cut neatly and the end faces must be free of delamination and cracks.
Characteristics: The FR4 sheet excellent mechanical properties, Plate properties: high temperature resistance. Electrical: The cured epoxy resin system is an excellent insulating material with high dielectric properties, surface leakage resistance and arc resistance.
Uses: Suitable for mechanical, electrical, electronic,new energy and other fields. Also used for the processing of insulating parts, processing into various types of insulating parts and equipment insulation structural parts. The reaction of the epoxy resin and the curing agent used is carried out by a direct addition reaction or a ring-opening polymerization reaction of an epoxy group in a resin molecule, without the release of water or other volatile by-products. They exhibit very low shrinkage (less than 2%) during curing compared
to unsaturated polyester resins and phenolic resins.
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