The performance of modern insulating ceramics should meet the following requirements:
1. The dielectric constant that can meet the technical requirements;
2. The lowest possible dielectric loss;
3. High volume resistivity and electrical strength;
4. Good dielectric temperature and frequency characteristics;
5. Excellent thermal conductivity, mechanical strength, fracture toughness, chemical stability and thermal stability.
Typical properties of alumina insulating ceramics:
Density (g/cm3): 3.6~3.8 (alumina 95)
Tensile strength (MPa): 300
Thermal expansion coefficient (X10^(-6)/°C): 6.5~8.0
Thermal Conductivity (W/m.K): 17
Volume resistivity (Ω.cm): 10^14 Min.
Dielectric constant (at 1MHz): 8.6
Dielectric loss (at 1MHz):/
Insulation strength (kV/mm): 35
Typical properties of steatite insulating ceramics:
Density (g/cm3): 2.8~3.1
Tensile strength (MPa): 140~300
Thermal expansion coefficient (X10^(-6)/°C): 7~7.5
Thermal conductivity (W/m.K):/
Volume resistivity (Ω.cm): 10^12 ~10^14
Dielectric constant (at 1MHz): 6~7
Dielectric loss (at 1MHz): (3-20) X 10^(-4)
Insulation strength (kV/mm): 20~30
