Patent ID: 8040657

Claim:
A ceramic multilayer substrate obtained by co-sintering low dielectric constant and high dielectric constant layers, the ceramic multilayer substrate comprising: a plurality of low dielectric constant layers, each comprising a ceramic component having a composition of xBaO-yTiO 2 -zZnO (“x”, “y” and “z” represent molar ratios, respectively, and satisfy the relationships: x+y+z=1; 0.09≦x≦0.20; 0.49≦y≦0.61; 0.19≦z≦0.42) and 1.0 to 5.0 weight parts of a glass component comprising boron oxide with respect to 100 weight parts of the ceramic component; a high dielectric constant layer comprising a barium titanate based dielectric material with CuO and Bi 2 O 3 added thereto; a layer of a BaO—Al 2 O 3 —SiO 2 series ceramic; and a pair of electrode layers; wherein the layer of the BaO—Al 2 O 3 —SiO 2 series ceramic is provided between and joined with the low dielectric constant layers and does not contact the high dielectric constant layer; wherein the pair of electrode layers are provided on main faces of the high dielectric constant layer, respectively, so that the pair of electrode layers provides a predetermined electrostatic capacity; and wherein the high dielectric constant layer is joined with the low dielectric constant layers at main faces thereof, respectively.