Laminated ceramic capacitor
US8208240B2 · kind B2 · utility
Assignee
Inventors
Key dates
| Filing date | Nov 29, 2007 |
| Grant date | Jun 26, 2012 |
| Priority date | — |
| Expiry date | Nov 3, 2028 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH01G4/30
- WIPO fieldElectrical machinery, apparatus, energy
- WIPO sectorElectrical engineering
Abstract
A crystal constituting a dielectric porcelain, comprised of a first crystal group composed of crystal grains of 0.2 atomic % or less calcium concentration and a second crystal group composed of crystal grains of 0.4 atomic % or more calcium concentration, wherein the ratio of concentration of each of magnesium and a first rare earth element contained in a center portion to that contained in a surface layer portion of crystal grains constituting the first crystal group is greater than the corresponding concentration ratio of crystal grains constituting the second crystal group, and wherein on a polished surface resulting from polishing of the surface of the dielectric porcelain, when the area of crystal grains of the first crystal group is referred to as a and the area of crystal grains of the second crystal group referred to as b, the ratio of b/(a+b) is in the range of 0.5 to 0.8.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.