FR-4 is a composite of a resin epoxy reinforced with a woven fiberglass mat. It is a material from the class of epoxy resin bonded glass fabric (ERBGF)
| Property | Value |
|---|---|
| Dielectric constant (permittivity) | 4.70 Max, 4.35 @ 500 MHz, 4.34 @ 1 GHz |
| Dissipation factor (loss tangent) | 0.02 @1 MHz, 0.01 @ 1 GHz |
| Dielectric strength | 20 MV/m (500 V/mil ) |
| Surface resistivity (min) | 2x10^5 MΩ |
| Volume resistivity (min) | 8x10^7 MΩ*cm |
| Typical thickness | 1.25 mm - 2.54 mm (0.049-0.100 inches) |
| Typical stiffness (Young's modulus) | 17 GPa (2.5x10^6 PSI; for use in PCBs) |
| Tg (glass transition temperature) FR4 laminate Tg ranges from 110 to ~200 depending on manufacture and resin system | |
| Density | 1.91 kg/L |
Pro 50 Ohmu, epsilon r = 4.5 (FR4), a tloustku dielektrika 1.5mm bude sirka pasku cca 2,7mm