Dielectric constant of advanced ceramics
The dielectric constant, also known as the relative permittivity (εr), is a measure of a material's ability to store electrical energy in an electric field. It represents the ratio of the material's dielectric constant to the vacuum dielectric constant (ε₀). The higher the dielectric constant, the greater the ability to store charge, which is critical in capacitors, insulators, and high-frequency electronic components.
Advanced ceramic materials are widely used in high-frequency, high-power, microwave, radar and packaging applications due to their different dielectric properties. When selecting materials, companies should consider factors such as operating frequency, thermal management, mechanical structure and dimensional accuracy to evaluate the best material combination.
The importance of dielectric constant in ceramics
Ceramic materials are widely used in electronics and electrical insulation because of their:
Dielectric constant plays a critical role in RF components, substrates, capacitors, antennas and semiconductor packages. Selecting the right ceramic material with the right dielectric constant ensures optimum performance, especially in high frequency and high temperature environments.
Factors affecting the dielectric constant of ceramics
Dielectric loss and frequency stability
εr determines the charge storage capacity, while the dielectric loss (tan δ) measures the energy dissipation. materials such as PTFE or h-BN have a very low tan δ, making them well suited for high-frequency RF designs.
Another factor is frequency dependence. Some ceramics (e.g., zirconia) have high dielectric constants but exhibit greater loss and instability in the GHz range, while AlN and Si₃N₄ remain more stable.
Dielectric Constants of Common Ceramic Materials
| Ceramic materials | Dielectric constant (εr) | hallmark |
|---|---|---|
| Aluminum oxide (Al₂O₃) | 9-10 | Low loss, structurally stable, cost-effective |
| Zirconium oxide (ZrO₂) | 18-25 | High strength, high thermal expansion |
| ZTA20 (zirconia toughened alumina) | 12-15 | Combined strength and dielectric properties |
| Silicon Nitride (Si₃N₄) | 7-8 | High strength, low dielectric loss |
| Aluminum Nitride (AlN) | 8.5-9 | High thermal conductivity, low dielectric loss |
| Silicon Carbide (SiC) | 9.7-10.2 | Excellent high frequency stability |
| Beryllium oxide (BeO) | 6.5-7.5 | High thermal conductivity, low εr |
| Hexagonal boron nitride (h-BN) | ~4 | Very low εr, excellent thermal stability |
| MGC (machinable glass-ceramics) | 5.6 | CNC machinable, ideal for microwave structures |
*Data is for reference only.
Material Selection Guide: Selecting Ceramics Based on Dielectric Constant
| application direction | recommendation material | rationale |
| High Frequency/Low Loss | Aluminum Nitride, Beryllium Oxide, Hexagonal Boron Nitride | Low εr + low loss + high thermal conductivity |
| Power Packaging/Cooling | Aluminum Nitride, Aluminum Oxide | Moderate εr + excellent heat dissipation |
| Radome/radome | MGC, BeO | Good processability + low εr |
| high frequency capacitor | Zirconium oxide (ZrO₂) | High εr + good mechanical strength |
| microwave structure | Magna | Easy processing + stable dielectric properties |
Need help choosing the right ceramic?
Choosing the right high-strength ceramic material is critical to ensuring long-term reliability and optimal performance. Whether you need zirconia, silicon nitride, or alumina-based ceramics, our materials provide industry-leading strength, durability, and precision.
Our technical team is here to help - contact us today for expert customized advice on your specific needs.
Dielectric constant: ceramics and other materials
To help you understand the advantages of ceramic dielectric constants for material selection, the table below compares ceramic materials with common insulator materials, materials for the electronics industry and polymer plastics:
*Data is for reference only.
Chinese 
English