Patent ID: 7501371

Claim:
A dielectric ceramic characterized by having a composition comprising a primary component represented by a general formula ABO 3 , in which A is Ba or Ba and Ca and B is Ti optionally in combination with at least one of Zr and Hf, and additional components comprising a rare-earth element and Cu and having a structure comprising crystal grains containing the ABO 3 primary component and grain boundaries between the crystal grains, wherein when a cross section of the dielectric ceramic is observed, the condition that the rare-earth element is present in 90% or more of the region of each crystal grain in 55% to 85% by number of the crystal grains, and the rare-earth element is present in less than 10% of the region of each crystal grain in 15% to 45% by number of the crystal grains, and the ratio of the average molar concentration of the rare-earth element in the grain boundaries to the average molar concentration of the rare-earth element in the regions in which the rare-earth element is present in the inside of the crystal grains is less than 2, and wherein the ABO 3 is represented by (Ba 1-x Ca x ) m TiO 3 , in which 0≦x≦0.03 and 1.001≦m≦1.012 and wherein the additional components comprise a rare-earth element, Mg, Mn, Cu and Si, and relative to 100 parts by mole of the ABO 3 : the rare-earth element is 0.1 part by mole or more and 1 part by mole or less; Mg is 0.1 part by mole or more and 2 parts by mole or less; Mn is 0.05 part by mole or more and 0.5 part by mole or less; Cu is 0.1 part by mole or more and 3 parts by mole or less; and Si is 0.2 part by mole or more and 2 parts by mole or less.