FR stands for "flame retardant", indicating that the material meets the UL94V-0 standard for flammability of plastic materials. It is not a material name, but a material grade, so there are many kinds of FR-4 grade materials used in general circuit boards, but most of them are epoxy resins with so-called four functions (Tera-Function). A composite material made of filler and glass fiber.

FR-4 epoxy glass fiber laminate, according to different uses, the industry is generally called: FR-4 Epoxy fiber Cloth, insulating board, epoxy board, epoxy resin board, brominated epoxy resin board, FR-4 , fiberglass board, fiberglass board, FR-4 reinforcement board, FPC reinforcement board, flexible circuit board reinforcement board, FR-4 epoxy resin board, flame retardant insulation board, FR-4 laminate board, epoxy board , FR-4 light board, FR-4 glass fiber board, epoxy glass cloth board, epoxy glass cloth laminate, circuit board drilling pad.

Main technical features and applications: stable electrical insulation, good flatness, smooth surface, no pits, thickness tolerance standard, suitable for products with high-performance electronic insulation requirements,

such as FPC reinforcement board, PCB drilling Backing plate, glass fiber meson, potentiometer carbon film printed glass fiber board, precision planetary gear (wafer grinding), precision test plate, electrical (electrical) equipment insulating stay spacer, insulating backing plate, transformer insulating plate, motor insulation , Grinding gears, electronic switch insulation boards, etc.