What is FR4 Sheet
FR4 Sheet, also known as epoxy fiberglass sheet or flame retardant insulation board, is fabricated by impregnating fiberglass woven cloth with flame-retardant epoxy resin and hot-pressed under high temperature and pressure. It is widely utilized in high-end precision equipment that demands high safety and reliability standards.

Core Functions
As high-performance insulating structural components for motors, electrical appliances, electronics and other equipment, FR4 Sheet mainly serves to separate live parts, avoid electric breakdown, and ensure safe and stable operation of equipment. It boasts outstanding flame retardancy, moisture resistance, heat resistance and dimensional stability, and can maintain stable performance in humid environments as well as transformer oil.
Typical Applications
Support components for distribution boxes, bus bar clamps for switch cabinets Precision planetary wheels, insulating gaskets for railway tracks Lithium battery separators, insulating partition plates for circuit breakers Cover plates for welding jigs, precision mold fixtures Heat insulation plates for plastic molds, insulating support components.
Performance Characteristics
Optional V0 flame retardant rating, self-extinguishes within 10 seconds after flame removal, compliant with international safety standards
Excellent electrical insulation performance featuring high dielectric strength and stable properties
High mechanical strength with great impact resistance and superior dimensional stability
Heat resistant, capable of long-term service under 130℃ constant temperature
Corrosion and moisture resistant, minimally affected by harsh working environments
Excellent flatness with smooth pit-free surface and precise thickness tolerance control
Superior machinability, allowing drilling, sawing, milling and precision forming processing
YILONG specializes in manufacturing Grade A and Grade B FR4 Sheet (EPGC202). We provide whole sheet wholesale, custom cutting, precision machining services, support non-standard customization and drawing-based processing solutions.
For any inquiries and cooperation needs, please feel free to contact YILONG.
Email: yilong@yilonginsulation.com
Website: www.yilonginsulation.com
Mob/Whatsapp: +8615866869385