Method of fabricating a multilayer ceramic capacitor
US5680685A · kind A · utility
Assignee
Inventor
Key dates
| Filing date | Jun 7, 1995 |
| Grant date | Oct 28, 1997 |
| Priority date | — |
| Expiry date | Jun 7, 2015 |
Classification
- Technology area (CPC Y)Emerging Cross-Sectional Technologies
- CPC primaryY10T29/49163
- WIPO fieldElectrical machinery, apparatus, energy
- WIPO sectorElectrical engineering
Abstract
A method of fabricating a large, rectangular, multilayer ceramic capacitor formed of alternating ceramic and electrode layers. Capacitors so formed have a high dielectric constant, extremely low leakage current and an extremely low dissipation factor. Exemplary capacitors can be made with a lead magnesium niobate dielectric composition powder to which is added several organic constituents, including a surfactant and a plasticizer, plus small amounts of several dopants, such as lithium niobate, copper oxide, magnesium titanate, manganese niobate and zirconium oxide. That total mixture is ball milled to form a slip with very small grain size. The slip is cast as a thin tape on a Mylar backing, cut into a plurality of blanks, and alternating layers of the green tape ceramic and electrode layers are laminated on a polyvinyl alcohol coated foundation plate. Firing and sintering steps are followed by application of electrical terminations to complete the capacitor. The final package is annealed to further improve the dielectric constant and the dissipation factor.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.