FR4 is the most commonly used base material for printed circuit boards (PCBs). It is a composite material made from woven fiberglass cloth impregnated with an epoxy resin binder. FR4 is known for its excellent mechanical strength, good electrical insulation properties, and flame retardancy, which is indicated by the "FR" (Flame Retardant) designation.
The material offers a good balance of properties suitable for a wide range of electronic applications.
FR4 is used in the vast majority of rigid PCBs, from simple single-layer boards to complex multi-layer designs found in consumer electronics, industrial controls, and telecommunications equipment.
While versatile, FR4 has limitations for very high-frequency or high-temperature applications, where specialized materials like Rogers laminates or high-Tg FR4 may be required.
