| 摘要 |
PROBLEM TO BE SOLVED: To obtain a microwave dielectric ceramic composition having a high Q-value is obtained by including a main component having a perovskite type crystal structure, Al2 O3 and one or more kinds of oxides of elements without Ca, Sr, Nd, Ti and Al in a specific weight proportion. SOLUTION: This microwave dielectric ceramic composition contains 100 wt.% main component having a perovskite type crystal structure of the formula (Cax , Sry , Ndz )1+a TiO3+b [(x), (y) and (z) are molar numbers; (x)+(y)+(z)=1; 0.430<=(x)<=0.650; 0.260<=(y)<=0.440; 0.090<=(z)<=0.130; 0.010<=(a)<=0.300; 0.100<=(b)<=1.000], 10-12 wt.% Al2 O3 and 1-2 wt.% one or more kinds of oxides of elements without Ca, Sr, Nd, Ti and Al, and has >=3,900 Q-value and dielectric characteristics of <=300 ppm/ deg.C absolute value of temperature coefficient τt of a resonance frequency. The oxide is selected from Nb2 O5 , Ta2 O5 , MnO2 , ZnO, Sb2 O3 , etc., and is especially and preferably 0.5-2.0 wt.% Nb2 O5 in combination with 0.05-0.3 MnO2 . |
