Patent ID: 8154851
Filing Date: 2012-04-10
Classification: C04B,H01G

Abstract:
1. A dielectric ceramic comprising: primary crystal grains comprising a composite oxide having first crystal grains comprising Ti, Ca and Ba, said first crystal grains having a Ca concentration of not more than 0.2 atomic percent, said primary crystal grains further comprise second crystal grains comprising a composite oxide comprised of Ti, Ca and Ba, and having a Ca concentration of not less than 0.4 atomic percent, and wherein the total amount of Ba and Ca is an amount A mol, and the amount of Ti is an amount B mol, the mole ratio (A/B) is not less than 1.003, wherein the primary crystal grains further comprise metal elements of Mg, Mn and a rare earth element, and at least one of the metal elements is present at a higher concentration on the surface side of the primary crystal grains than the inside thereof, a concentration ratio thereof (the surface side/the inside) being at least 1.5, wherein 0.04 to 0.2 parts by mass of Zr in terms of oxide to 100 parts by mass of the total amount of the composite oxides comprising the first crystal grains and the second crystal grains is contained, and wherein the dielectric constant of the ceramic composition is 3580 or above.