FR4 Dielektrizitätskonstante Tabelle
Frequenzabhängige Eigenschaften von Standard FR4
FR4 Dielektrizitätskonstante Tabelle
Use this reference chart to estimate how standard FR4 dielectric constant and dissipation factor shift with frequency before final impedance and material decisions.
Die Dielektrizitätskonstante (Dk, εr) und der Verlustfaktor (Df) variieren mit der Frequenz. Nutzen Sie diese Tabelle als Referenz für Standard FR4 (Tg 130-140°C).
| Frequenz | Dielektrizitätskonstante (Dk) | Verlustfaktor (Df) |
|---|---|---|
| 1 MHz | 4.7 | 0.015 |
| 10 MHz | 4.6 | 0.018 |
| 100 MHz | 4.5 | 0.020 |
| 1 GHz | 4.35 | 0.022 |
| 2.5 GHz | 4.30 | 0.023 |
| 5 GHz | 4.25 | 0.025 |
| 10 GHz | 4.20 | 0.028 |
| 20 GHz | 4.15 | 0.030 |
These values are directional engineering reference data for standard FR4 only. Actual dielectric behavior depends on laminate family, resin system, glass style, copper profile, processing, and test method. Final controlled-impedance work should use exact material data from your PCB manufacturer.
When to use this tool
Check whether your assumed dielectric constant is directionally reasonable before estimating controlled impedance and trace geometry.
Use it to understand where standard FR4 starts to become a weak fit for loss-sensitive or higher-frequency routing.
Bring this into stackup discussions when you need to compare standard FR4 assumptions with real laminate data and fabrication capability.
Practical notes
• Standard FR4 can work for many digital and general-purpose boards, but it is not automatically the right material for every impedance-critical design.
• Dk shifts affect propagation speed and impedance; Df shifts affect insertion loss and signal attenuation.
• At higher frequencies, simplified assumptions become less reliable and material selection becomes more important.
Warum ist Dk wichtig?
Warum ist Df wichtig?
Related resources & next steps
Use dielectric assumptions from this reference to estimate single-ended impedance targets.
Cross-check geometry decisions when signal and current requirements need to coexist on the same board.
Move from generic FR4 assumptions to stackup, laminate, and fabrication-ready review.
Send your target impedance, frequency range, and material questions to engineering.
Häufige Fragen
FR4 für 5G?
Nein, Df zu hoch. Nutzen Sie spezielle HF-Laminate.
Temperaturrelevanz?
Ja, Dk steigt mit Temperatur. TcDk beachten.
Need help choosing laminate assumptions for impedance-critical PCB work?
We can help review FR4 suitability, dielectric targets, frequency risk, and manufacturing stackup decisions before you lock routing or controlled impedance requirements.