CERAMIC COMPOSITION FOR HIGH-FREQUENCY, AND CERAMIC FOR HIGH-FREQUENCY AND ITS PRODUCTION

摘要

PROBLEM TO BE SOLVED: To obtain both a ceramic composition and a ceramic which can be baked at 800-1,000 deg.C, has low dielectric constant, low dielectric loss, high strength, and a coefficient of thermal expansion a appropriate to those of a chip part such as GaAs and a printed wiring board in a high-frequency range, can be mounted on the chip part and the printed wiring board in a high reliability, and are both useful for an insulating substrate of wiring board for high-frequency, and to provide a method for producing the ceramic. SOLUTION: A mixture of 50-95 wt.% of glass containing SiO2, Al2O3, MgO and CaO, capable of precipitating diopside type oxide crystal phase, 5-49.9 wt.% of the total of quartz and/or amorphous silica and 0.1-20 wt.%, calculated as MgO, of at least one selected from MgO, MgCO3, Mg(OH)2 and compound oxide of Mg and Si is molded, baked at 800-1,000 deg.C to give a ceramic having >=5.5 ppm/ deg.C coefficient of thermal expansion, <=7 dielectric constant and <=30×10-4 dielectric loss at 60-77 GHz.