Ceramic multilayer chip capacitor and method for making

A method for preparing a ceramic multilayer chip capacitor, comprising the steps of:

• alternately stacking a dielectric material and an electrode-forming nickel or nickel alloy material to form a stack of dielectric layers and internal electrodes, said dielectric material containing 0.005 to 2% by weight, calculated as MnO, of a manganese compound and/or 0.005 to 5% by weight, calculated as P.sub.2 O.sub.5, of a phosphorus compound based on the weight of the dielectric material,
• firing the stack under an oxygen partial pressure of up to 10.sup.-8 atm., and
• then heat treating the stack at a temperature of 900.degree. to 200.degree. C. under an oxygen partial pressure of at least 10.sup.-8 atm., thereby re-oxidizing the dielectric layers to form an oxide layer having a different composition from the dielectric layers in close proximity to the internal electrodes.

A ceramic multilayer chip capacitor comprising

• internal electrodes of nickel or a nickel alloy, and
• dielectric layers stacked alternately with the internal electrodes,
• wherein the dielectric layers consist essentially of grains and a grain boundary phase, the percent area of the grain boundary phase being up to 2% of the area of a cross section of the dielectric layer.

A method for preparing a ceramic multilayer chip capacitor, comprising the steps of:

• alternately stacking a dielectric material and an electrode-forming nickel or nickel alloy material to form a stack of dielectric layers and internal electrodes,
• firing the stack under an oxygen partial pressure of up to 3.times.10.sup.-9 atm., and
• then heat treating the stack at a temperature of 900.degree. to 1200.degree. C. under an oxygen partial pressure of at least 10.sup.-8 atm., thereby re-oxidizing the dielectric layers such that the dielectric layers consist essentially of grains and a grain boundary phase, the percent area of the grain boundary phase being up to 2% of the area of a cross section of the dielectric layer.