Dielectric ceramic composition, dielectric ceramic and laminated ceramic part including the same

A material composition for dielectric ceramics represented by general formula (1):

• aZnAl2O4-bZn2SiO4-cTiO2-dZn2TiO4, in which the molar fractions of respective components a, b, c, and d satisfy 5.0≦a≦80.0 mol %, 5.0≦b≦70.0 mol %, 5.0≦c≦27.5 mol %, 0≦d≦30.0 mol % (a+b+c+d=100 mol %).

A dielectric ceramic composition containing a Li compound as a subcomponent in an amount of 2 to 30 parts by weight in terms of Li2O and a glass component in an amount of 5 to 150 parts by weight, based on 100 parts by weight of a main component comprising a calcined body obtained by calcining a material composition represented by general formula (2):

• aZnO-bAl2O3-cSiO2-d(xCaO-(1-x)TiO2), in which the molar fractions of respective components a, b, c, and d satisfy 7.5≦a≦55.0 mol %, 5.0≦b≦65.0 mol %, 5.0≦c≦0.70.0 mol %, 7.5≦d≦27.5 mol % (a+b+c+d=100 mol %) and x satisfies 0≦x≦0.75.

A material composition for dielectric ceramics represented by general formula (2):

• aZnO-bAl2O3-cSiO2-d(xCaO-(1-x)TiO2), in which the molar fractions of respective components a, b, c, and d satisfy 7.5≦a≦55.0 mol %, 5.0≦b≦65.0 mol %, 5.0≦c≦0.70.0 mol %, 7.5≦d≦27.5 mol % (a+b+c+d=100 mol %) and x satisfies 0≦x≦0.75.

A method of producing a dielectric ceramic composition, comprising the steps of:

• calcining a material composition represented by general formula (2):
• aZnO-bAl2O3-cSiO2-d(xCaO-(1-x)TiO2), in which the molar fractions of respective components a, b, c, and d satisfy 7.5≦a≦55.0 mol %, 5.0≦b≦65.0 mol %, 5.0≦c≦0.70.0 mol %, 7.5≦d≦27.5 mol % (a+b+c+d=100 mol %) and x satisfies 0≦x≦0.75, at from 900 to 1200° C. to obtain a calcined body, and
• mixing the calcined body with a Li compound as a subcomponent in an amount of 2 to 30 parts by weight in terms of Li2O and a glass component in an amount of 5 to 150 parts by weight, based on 100 parts by weight of a main component comprising the calcined body.

A dielectric ceramic composition containing a Li compound as a subcomponent in an amount of 2 to 30 parts by weight in terms of Li2O and a glass component in an amount of 5 to 150 parts by weight, based on 100 parts by weight of a main component represented by general formula (3):

• aZnAl2O4-bZn2SiO4-cSiO2-dSrTiO3, in which the molar fractions of respective components a, b, c, and d satisfy 2.5≦a≦77.5 mol %, 2.5≦b≦77.5 mol %, 2.5≦c≦37.5 mol %, 10.0≦d≦17.5 mol % (a+b+c+d=100 mol %).

A material composition for dielectric ceramics represented by general formula (3):

• aZnAl2O4-bZn2SiO4-cSiO2-dSrTiO3, in which the molar fractions of respective components a, b, c, and d satisfy 2.5≦a≦77.5 mol %, 2.5≦b≦77.5 mol %, 2.5≦c≦37.5 mol %, 10.0≦d≦17.5 mol % (a+b+c+d=100 mol %).

A dielectric ceramic composition containing a Li compound as a subcomponent in an amount of 1 to 15 parts by weight in terms of Li2O and a glass component in an amount of 5 to 150 parts by weight, based on 100 parts by weight of a main component represented by general formula (4):

• aMg2SiO4-bZnAl2O4-cSiO2-dCaTiO3-eZn2SiO4, in which the molar fractions of respective components a, b, c, d, and e satisfy 0.10≦a≦0.72, 0.08≦b≦0.62, 0.02≦c≦0.22, 0.12≦d≦0.22, 0≦e≦0.08 (a+b+c+d+e=1).

A material composition for dielectric ceramics represented by general formula (4):

• aMg2SiO4-bZnAl2O4-cSiO2-dCaTiO3-eZn2SiO4, in which the molar fractions of respective components a, b, c, d, and e satisfy 0.10≦a≦0.72, 0.08≦b≦0.62, 0.02≦c≦0.22, 0.12≦d≦0.22, 0≦e≦0.08 (a+b+c+d+e 1.