Multilayered ceramic capacitor
US8059388B2 · kind B2 · utility
Assignee
Inventors
Key dates
| Filing date | Nov 29, 2007 |
| Grant date | Nov 15, 2011 |
| Priority date | — |
| Expiry date | Jul 2, 2028 |
Classification
- Technology area (CPC C)Chemistry; Metallurgy
- CPC primaryC04B2235/85
- WIPO fieldElectrical machinery, apparatus, energy
- WIPO sectorElectrical engineering
Abstract
The invention relates to a multilayer ceramic capacitor having dielectric layers and internal electrode layers disposed alternately. The dielectric layers include a dielectric ceramic containing barium titanate as a main component, and also calcium, magnesium, vanadium, manganese, and a rare-earth element. Crystals constituting the dielectric ceramic are constituted by grains containing barium titanate as their main component and containing calcium in a concentration of 0.2 atomic % or less or containing the calcium in a concentration of 0.4 atomic % or more. The crystals grains are also distinct in their relative distributions of magnesium and rare-earth elements between the center of the grain and the surface of the grain. Finally, the relative areas of the two kinds of crystals observed in the plane of a polished surface of the dielectric ceramic are described by a ratio b/(a+b), which is 0.5 to 0.8.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.