| abstract |
High-frequency ceramics containing SiO 2 , Al 2 O 3 , MgO, ZnO and B 2 O 3 as constituent components, said ceramics comprising: 30 to 50% by weight of a crystal phase containing ZnO and Al 2 O 3 ; 5 to 15% by weight of a crystal phase containing SiO 2 and MgO; and 40 to 60% by weight of an amorphous phase comprising substantially SiO 2 or SiO 2 and B 2 O 3 ; wherein the content of the SiO 2 crystal phase is suppressed to be not larger than 6% by weight. The ceramics has a dielectric loss at 60 GHz of not larger than 15×10 −4 , exhibiting excellent high-frequency characteristics, and is very useful as an insulating substrate for the wiring boards that deal with high-frequency signals. |