Microwave dielectric ceramic composition
US5340784A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Aug 2, 1993 |
| Grant date | Aug 23, 1994 |
| Priority date | — |
| Expiry date | Aug 2, 2013 |
Classification
- Technology area (CPC C)Chemistry; Metallurgy
- CPC primaryC04B35/465
- WIPO fieldMaterials, metallurgy
- WIPO sectorChemistry
Abstract
Disclosed herein is a microwave dielectric ceramic composition which comprises as the main ingredient, a composition represented by xMgTiO.sub.3 .multidot.(1-x)CaTiO.sub.3 (0.93.ltoreq.x .ltoreq.0.95), to which 3-9 wt % of ZnO, 2-4 wt % of Ta.sub.2 O.sub.5, 1-6 wt % of Nb.sub.2 O.sub.5, 0.1-6 wt % of MnO.sub.2, 3-12 wt % of Al.sub.2 O.sub.3 or 3-12 wt % of Co.sub.2 O.sub.3 to xMgTiO.sub.3 .multidot.(1-x)CaTiO.sub.3. And the microwave dielectric ceramic compositions have a Qu value in the range of 3000 to 4600 (at 6 GHz), a temperature coefficient of the resonance frequency (.tau.f) in the range of -10 to +10 ppm/.degree.C. and relative dielectric constant (.epsilon..sub.r) in the range of 18 to 22. The dielectric ceramic compositions are capable of reducing .tau.f approximately to zero or optionally and stably controlling .tau.f to a desired value both to positive and negative sides around zero as the center while maintaining .epsilon..sub.r and Qu within practical characteristic ranges by controlling the addition (constitution) ratio of the specified oxides. Further, even if the sintering temperature is changed within a wide range, the sintering products of high density and high q…
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.