- Material Composition:
- Base Layer: Woven fiberglass (glass fiber reinforced epoxy laminate).
- Copper Layer: 1 oz to 6 oz (typically 1 oz = 35 µm) for conductive traces.
- Surface Finish: Options include HASL (Hot Air Solder Leveling), ENIG (Electroless Nickel Immersion Gold), and OSP (Organic Solderability Preservative).
- Electrical Properties:
- Dielectric Constant (Dk): ~4.3–4.8 (varies with frequency).
- Insulation Resistance: High (≥10⁴ MΩ).
- Thermal & Mechanical Properties:
- Glass Transition Temperature (Tg): 130–180°C (standard FR4); high-Tg FR4 (>180°C) is available for demanding environments.
- Thermal Conductivity: Low (~0.3 W/m·K), making heat dissipation a challenge vs. metal-core PCBs.
- Flexural Strength: Rigid and durable for most applications.
