Method of making ceramic dielectric for base metal electrode capacitors

Claim 1

A method of manufacturing a base metal electrode multilayer ceramic capacitor comprising the steps of: (a) preparing a tape from a ceramic powder, a binder, and a solvent; (b) forming a monolithic body of multiple layers of said tape and multiple layers of a metal electrode material, the electrode layers being interposed between each tape layer; and (c) sintering the body; characterized in that: said ceramic powder consists essentially of a major amount of BaO and TiO 2 , the amounts of BaO and TiO 2 being approximately equal, a minor amount of CaO and ZrO 2 sufficient to shift and broaden the Curie peak of the ceramic to a preselected value, and MgO, wherein the MgO is at least approximately 1 mole % of the ceramic powder and the large to small cation ratio of the ceramic powder is less than or equal to 0.98 but greater than or equal to 0.89; said metal electrode material is selected from the group comprising Ni and Co; and said body is sintered at a temperature in the range of 1200° C. to 1425° C. in an atmosphere having an oxygen partial pressure which is between a maximum which is at least reducing to the oxide of the metal electrode material and a minimum of approximately 10 -11 atmosphere.

Claim 2

A method of manufacturing a base metal electrode multilayer ceramic capacitor comprising the steps of: (a) preparing a tape from a ceramic powder, a binder, and a solvent; (b) forming a monolithic body of multiple layers of said tape and multiple layers of a metal electrode material, the electrode layers being interposed between each tape layer; and (c) sintering the body; characterized in that: said ceramic powder consists essentially of a major amount of BaO and TiO 2 , the amounts of BaO and TiO 2 being approximately equal, a minor amount of CaO and ZrO 2 sufficient to shift and broaden the Curie peak of the ceramic to a preselected value, and MgO, wherein the MgO is at least approximately 1 mole % of the ceramic powder and the large to small cation ratio of the ceramic powder is less than or equal to 0.98 but greater than or equal to 0.89; said metal electrode material is selected from the group comprising Ni and Co; and said body is sintered at a temperature in the range of 1200° C. to 1425° C. in an atmosphere having an oxygen partial pressure which is between a maximum which is at least reducing to the oxide of the metal electrode material and a minimum of approximately 10 -11 atmosphere.