Dielectric ceramic, method for producing the same, laminated ceramic electronic element, and method for producing the same
US6383323B1 · kind B1 · utility
Assignee
Inventors
Key dates
| Filing date | Aug 23, 2001 |
| Grant date | May 7, 2002 |
| Priority date | — |
| Expiry date | Aug 23, 2021 |
Classification
- Technology area (CPC C)Chemistry; Metallurgy
- CPC primaryC04B35/4682
- WIPO fieldElectrical machinery, apparatus, energy
- WIPO sectorElectrical engineering
Abstract
A dielectric ceramic which exhibits small variation in dielectric constant, allows use of a base metal, can be fired in a reducing atmosphere and which is suitable for constituting a dielectric ceramic layer for, e.g., a laminated ceramic capacitor is obtained by firing barium titanate powder in which the c-axis/a-axis ratio in the perovskite structure is about 1.000 or more and less than about 1.003 and the amount of OH groups in the crystal lattice is about 2.0 wt. % or less. The barium titanate powder starting material preferably has a maximum particle size of about 0.3 &mgr;m or less and an average particle size of about 0.05-0.15 &mgr;m. Each particle of the barium titanate powder preferably comprises a low-crystallinity portion and a high-crystallinity portion, the diameter of the low-crystallinity portion being about 0.5 times or more the particle size of the powder. When sintered, the powder satisfies the ratio of (average grain size of the fired dielectric ceramic)/(average particle size of barium titanate powder starting material), R, of about 0.90-1.2, to thereby suppress considerable grain growth. A laminated ceramic electronic element including a laminate of a pluralit…
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.