FR-4 is a flame retardant material grade code, representing a composite material based on epoxy resin and glass fiber cloth, which is widely used in PCB manufacturing and electronic insulation.
FR-4 is a key
material widely used in the electronics industry. Its core characteristics and
applications are as follows:
1. Definition and
essence
• Material grade
rather than specific name: FR-4 is a flame retardant grade code established by
NEMA (National Electrical Manufacturers Association), indicating that the resin
is epoxy resin, the reinforcement material is glass fiber cloth, and the flame
retardant grade reaches UL94 V-0 standard.
• Composition: It is mainly composed of four-functional epoxy resin, filler (Filler) and electronic grade glass fiber cloth, and is made by high temperature and high pressure lamination process.
2. Key features
• Flame
retardancy: Meets UL94 V-0 standard and can self-extinguish when burning.
• Electrical
performance: Stable dielectric constant (Dk) (e.g. 4.5), excellent insulation,
suitable for high-frequency circuits.
• Mechanical
strength: High rigidity, heat resistance and moisture resistance, can be
precisely processed.
• Thermal management: Low coefficient of thermal expansion (CTE), suitable for high temperature environments.
3. Application
areas
• PCB
manufacturing: As the mainstream substrate, it is used for multi-layer circuit
boards (such as four-layer LED driver boards) to provide electromagnetic
compatibility and current carrying capacity.
• Insulation
components: including transformer insulation boards, motor insulation parts,
FPC reinforcement boards, etc.
• Industrial
equipment: such as grinding gears, testing boards, etc., which require high
mechanical strength.