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US 7,706,125 B2Granted
Multilayer ceramic capacitor and production method of the same
AssigneeKYOCERA Corporation
InventorsDaisuke Fukuda, Kiyoshi Matsubara, Masahiro Nishigaki
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Abstract
The invention provides a multilayer ceramic capacitor comprising a capacitor body composed by alternately layering dielectric layers and inner electrode layers. Accordingly, the multilayer ceramic capacitor has high relative permittivity and is high the temperature property and highly accelerated life test property.
Claims8
A multilayer ceramic capacitor comprising a capacitor body composed by alternately layering dielectric layers and inner electrode layers,
- wherein each of said dielectric layers comprises the following conditions (a) and (b):
- (a) comprising a plurality of crystal particles, and grain boundary phases comprising interfacial grain boundaries and triple point grain boundaries formed among a plurality of the crystal particles adjacent to one another;
- and
- (b) Si—Ba—O compound being formed in 5% or more of the triple point grain boundaries in the entire triple point grain boundaries per unit surface area of the dielectric layer.
1 more element
A method for producing a multilayer ceramic capacitor, comprising the steps of:
- forming a green sheet by adding oxides of Mg, rare earth elements, and Mn, glass powder containing 0.1% by mass or less of alumina, barium carbonate powder, and an organic resin into dielectric powder mixing of a perovskite type barium titanate powder (BCT powder) wherein a portion of A site is replace with Ca, and a perovskite barium titanate powder (BT) containing no substituent Ca;
- forming a green body of a capacitor body composed by alternately laminating the green sheets and inner electrode patterns;
- and sintering the green body of the capacitor body;
- wherein in the case the amount of barium and Ca is defined as A, and the amount of titanium is defined as B in the BCT powder, the A/B ratio by mole satisfies A/B≧1.003;
- wherein 0.7 to 2 parts by mass of glass powder is added to 100 parts by mass of the dielectric powder;
- and
- wherein 0.01 to 1 parts by mass of the barium carbonate powder is added to 100 parts by mass of the dielectric powder.
4 more elements
Dependencies are inferred from the claim text.