摘要 |
PURPOSE: A microwave dielectric ceramic composition of the xBaO-ySm2O3-zTiO2 system and a ceramic capacitor using the composition are provided, which has high dielectric constant, large Q value at high frequency, low temperature coefficient of resonant frequency, and low temperature sintering. CONSTITUTION: The dielectric ceramic composition comprises xBaO-ySm2O3- zTiO2(0.05<=x<=0.30, 0.05<=y<=0.20 0.65<=z<=0.75, and x=y+z=1) as main components, 0.05-8wt.% of CuO, 0.01-5wt.% of ZnO and 0.1-10wt.% of glass composition based on ZnO-SiO2 or Li2O-Al2O3-SiO2 as auxiliary components, and optionally 0.005-2.5wt.% of rare earth oxides such as Y2O3, Ho2O3, Dy2O3, Yb2O3 and Ce2O3, more than 3wt.% of PbO, and more than 3wt.% of Bi2O3 or Al2O3. The ceramic capacitors are produced by mixing components, bulk-forming, electroding and sintering at 850-1050deg.C, and the ceramic multilayer capacitors are produced by mixing components, sheet-forming, electroding, multilayering, and sintering at 850-1050deg.C. The lowered sintering temperature compared with conventional sintering temperature, 1200-1400deg.C, enables use of electrodes made of non metals(Cu, Ni, W, Mo, etc.) or carbon-based materials, which results in low-cost production.
|