US5296426A
Expired / Lapsed
US
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Low-fire X7R compositions
Assignee: EIDP Inc
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Filing: 1992-07-20
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Granted: 1994-03-22
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Expires: 2012-07-20
Abstract
Abstract A composition for forming a densified ceramic dielectric body, the composition consisting essentially of (a) about 96.0-98.0 wt. % barium titanate having an average particle size of 0.5-1.25 microns; (b) 0.3-1.2 wt. % niobium oxide or precursor thereof; (c) 0.4-1.2 wt. % zinc oxide or precursor thereof; (d) 0.1-1.2 wt. % neodymium oxide or precursor thereof; (e) 0.15-0.75 wt. % boron oxide or precursor thereof; and (f)0-0.1 wt. % manganese oxide or precursor thereof. This composition can be used to form the dielectric layers in multilayer electrical devices such as circuits and capacitors.
Inventors
- 👤 Ian Burn
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-08 16:34
CPC Classifications
H; H01; H01G; H01G4/00; H01G4/002; H01G4/018; H01G4/06; H01G4/08; H01G4/12; H01G4/1209; H01G4/1218; H01G4/1227; C; C04; C04B; C04B35/00; C04B35/01; C04B35/46; C04B35/462; C04B35/465; C04B35/468
Claims Analysis
Total Claims: 13
Claim 1
Independent Claim
153 words
A composition for forming a densified ceramic dielectric body at a temperature below 1150° which dielectric body has a dielectric constant of at least 2500, a temperature coefficient of capacitance that remains within +/-15% of the value at 25° C. over the range of -55° C. to 125° C., a dissipation factor of not more than 2.5% at 25° C. and 1 kHz with 1.0 V applied, and an insulation resistance of at least 1000 ohm.farads at 25° C. and at least 100 ohm.farads at 125° C., the composition consisting essentially of: (a) about 96.0-98.0 wt. % barium titanate having an average particle size of 0.5-1.25 microns; (b) 0.3-1.2 wt. % niobium oxide or precursor thereof; (c) 0.4-1.2 wt. % zinc oxide or precursor thereof; (d) 0.1-1.2 wt. % neodymium oxide or precursor thereof; (e) 0.15-0.75 wt. % boron oxide or precursor thereof; and (f) 0-0.1 wt. % manganese oxide or precursor thereof.
Claim 2
Dependent Claim
153 words
A composition for forming a densified ceramic dielectric body at a temperature below 1150° which dielectric body has a dielectric constant of at least 2500, a temperature coefficient of capacitance that remains within +/-15% of the value at 25° C. over the range of -55° C. to 125° C., a dissipation factor of not more than 2.5% at 25° C. and 1 kHz with 1.0 V applied, and an insulation resistance of at least 1000 ohm.farads at 25° C. and at least 100 ohm.farads at 125° C., the composition consisting essentially of: (a) about 96.0-98.0 wt. % barium titanate having an average particle size of 0.5-1.25 microns; (b) 0.3-1.2 wt. % niobium oxide or precursor thereof; (c) 0.4-1.2 wt. % zinc oxide or precursor thereof; (d) 0.1-1.2 wt. % neodymium oxide or precursor thereof; (e) 0.15-0.75 wt. % boron oxide or precursor thereof; and (f) 0-0.1 wt. % manganese oxide or precursor thereof.
Claim 3
Dependent Claim
62 words
The composition of claim 1 consisting essentially of finely divided particles of: (a) about 96.0-98.0 wt. % barium titanate having an average particle size of 0.5-1.25 microns; (b) 0.3-1.2 wt. % niobium oxide having an average particle size of 0.5-1.0 microns; (c) 0.65-3.15 wt. % zinc-neodymium-borate flux having an average particle size of 0.5-1.25 microns; and (d) 0-0.1 wt. % manganese oxide.
Claim 4
Dependent Claim
25 words
The composition of claim 1 wherein the oxides of niobium, zinc, neodymium, boron and manganese, or precursors thereof, are coated on the barium titanate particles.
Claim 5
Dependent Claim
37 words
The composition of claim 1 wherein up to 20 mole % of the neodymium oxide is replaced by an oxide of a rare earth metal selected from the group consisting of Ce, Pr, Sm and mixtures thereof.
Claim 6
Dependent Claim
28 words
The composition of claim 1 wherein up to 50 mole % of the neodymium oxide is replaced by barium oxide, an alkaline-earth oxide or mixture of alkaline-earth oxide.
Claim 7
Dependent Claim
19 words
The composition of claim 1 wherein up to 33 mole % of the boron oxide is replaced by alumina.
Claim 8
Dependent Claim
62 words
The composition of claim 6 consisting essentially of finely divided particles of: (a) about 96.0-98.0 wt. % barium titanate having an average particle size of 0.5-1.25 microns; (b) 0.3-1.2 wt. % niobium oxide having an average particle size of 0.5-1.0 microns; (c) 0.65-3.15 wt. % zinc-neodymium-aluminoborate flux having an average particle size of 0.5-1.25 microns; and (d) 0-0.1 wt. % manganese oxide.
Claim 9
Dependent Claim
30 words
The composition of claim 1 further comprising an organic medium in which components (a)-(e) are dispersed, the organic medium comprising a solution of volatile organic solvent and organic polymeric binder.
Claim 10
Dependent Claim
23 words
A dielectric sheet comprising a cast layer of the composition of claim 8 which has been heated to remove the volatile organic medium.
Claim 11
Dependent Claim
29 words
A dielectric ceramic layer comprising the dielectric sheet of claim 9 which has been fired to volatilize the organic medium therefrom and to densify the inorganic components by sintering.
Claim 12
Dependent Claim
19 words
A multilayer element comprising a plurality of the dielectric ceramic layers of claim 10 interspersed with electrically conductive layers.
Claim 13
Dependent Claim
55 words
A multilayer capacitor comprising a plurality of the dielectric sheets of claim 7 having a thick film electrode layer therebetween, the assemblage having been fired at a temperature below the melting point of the conductive metal in the electrode layer to volatilize organic medium and to sinter the inorganic materials without melting the conductive metal.
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USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1997-03-21 | 1997-09-20 | 1998-03-22 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 2001-03-21 | 2001-09-20 | 2002-03-22 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2005-03-21 | 2005-09-20 | 2006-03-22 | $7700.00 | Window Closed / Lapsed |