ألواح ألياف زجاجية FR4
FR4 fiberglass sheets are glass-epoxy laminates made by impregnating woven electrical-grade fiberglass cloth with epoxy resin and curing it under heat and pressure. The designation stands for Flame Retardant level 4, and the material meets NEMA grade FR4 (IEC 60893 type EPGC202), performing like G10 but with a UL 94 V-0 flammability rating.
The woven glass and epoxy matrix gives FR4 a strong strength-to-weight ratio, tight dimensional stability, and excellent electrical insulation. It resists moisture, chemicals, and tracking, and holds its mechanical and dielectric properties across a wide temperature band, which is why it is the default substrate for printed circuit boards and a favored structural insulator in electrical equipment.
Beyond PCB substrates, FR4 is machined into insulating spacers, busbar supports, switchgear components, test fixtures, and structural parts. The sheets cut cleanly on CNC routers, drilling machines, and waterjets, and are stocked in standard sizes with thicknesses from 0.5 mm up to 50 mm in matte or gloss surfaces.









