| 主权项 |
1. A ceramic insulator material comprising a silicon nitride ceramic comprising β-Si3N4 or β-SiAlON grains and a barium-aluminum silicate phase surrounding the grains, wherein the ceramic insulator material has a dielectric strength of greater than 10 KV/mm, a modulus of rupture strength of at least 500 MPa, a dielectric constant of less than 8.3, a dielectric loss tangent less than 0.003 at 1 MHz, a fracture toughness of at least 5.5 MPa·m1/2, a thermal expansion coefficient of less than 4×10−6 1/° C., and a porosity level less than 0.06%. |
