Patent US3689824A successfully refreshed from Google Patents.
Patent US4882305A successfully refreshed from Google Patents.
US4882305A
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US
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Dielectric ceramic composition with high dielectric constant and flat TC characteristics
Assignee: Tam Ceramics LLC
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Filing: 1987-10-09
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Granted: 1989-11-21
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Expires: 2007-10-09
Abstract
Abstract The present invention provides ceramic compositions for preparing multi-layer capacitors (MLCs) having high dielectric constants between about 3000 and 4700 and stable temperature coefficients (TC) prepared from high purity barium titanate, niobium pentoxide and cobalt oxide.
Inventors
- 👤 Mike S. H. Chu
- 👤 Charles E. Hodgkins
- 👤 Terence C. Dean
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-08 17:16
CPC Classifications
C; C04; C04B; C04B35/00; C04B35/01; C04B35/46; C04B35/462; C04B35/465; C04B35/468; C04B35/4682; C04B35/48; H; H01; H01G; H01G4/00; H01G4/002; H01G4/018; H01G4/06; H01G4/08; H01G4/12; H01G4/1209; H01G4/1218; H01G4/1227
Claims Analysis
Total Claims: 8
Claim 1
Independent Claim
122 words
A ceramic composition having a dielectric constant between about 3,000 and 4,700 at 25° C. consisting of about 97.7-98.99% wt barium titanate; about 0.85-1.69% wt of niobium pentoxide; about 0.09-1.20% of cobalt oxide; about a wt ratio of niobium pentoxide to cobalt oxide of about 3.30 to 18.00 and wherein the barium titanate has a purity of about 99.0%, a BaO/TiO 2 stoichiometric ratio of about 0.950 to 0.995; and an average particle size of about 0.90 μm to 1.30 μm; the niobium pentoxide has a purity of about 99.0% and a particle size of about 0.5 to 0.9 μm; and the cobalt oxide has a purity of about 70% to 74% and a particle size of less than about 1.0 μm.
Claim 2
Dependent Claim
122 words
A ceramic composition having a dielectric constant between about 3,000 and 4,700 at 25° C. consisting of about 97.7-98.99% wt barium titanate; about 0.85-1.69% wt of niobium pentoxide; about 0.09-1.20% of cobalt oxide; about a wt ratio of niobium pentoxide to cobalt oxide of about 3.30 to 18.00 and wherein the barium titanate has a purity of about 99.0%, a BaO/TiO 2 stoichiometric ratio of about 0.950 to 0.995; and an average particle size of about 0.90 μm to 1.30 μm; the niobium pentoxide has a purity of about 99.0% and a particle size of about 0.5 to 0.9 μm; and the cobalt oxide has a purity of about 70% to 74% and a particle size of less than about 1.0 μm.
Claim 3
Dependent Claim
40 words
The ceramic composition of claim 1 wherein: the barium titanate is about 98.82% wt; the niobium pentoxide is about 0.98% wt; the cobalt oxide is about 0.20% wt; and the niobium pentoxide to cobalt oxide weight ratio is about 4.90.
Claim 4
Dependent Claim
91 words
A ceramic composition useful for making MLCs having high dielectric constants and TC characteristics that vary no more than about ±15 percent from their reference value at 25° C. over a temperature range of -55° C. to 125° C., the composition consisting a mixture of: about 97.70 -98.99 % wt barium titanate; about 0.85 -1.69 % wt of niobium pentoxide; about 0.09 -1.20 % wt of cobalt oxide; having a weight ratio of niobium pentoxide to cobalt oxide of about 3.30 to 18.00; and the mixture dispersed in a binder composition.
Claim 5
Dependent Claim
91 words
A ceramic composition useful for making MLCs having high dielectric constants and TC characteristics that vary no more than about ±15 percent from their reference value at 25° C. over a temperature range of -55° C. to 125° C., the composition consisting a mixture of: about 97.70 -98.99 % wt barium titanate; about 0.85 -1.69 % wt of niobium pentoxide; about 0.09 -1.20 % wt of cobalt oxide; having a weight ratio of niobium pentoxide to cobalt oxide of about 3.30 to 18.00; and the mixture dispersed in a binder composition.
Claim 6
Dependent Claim
37 words
The ceramic composition of claim 3, wherein: the barium titanate has a purity greater than about 99.0%, the BaO/TiO 2 stoichiometric ratio is about 0.950 to 0.995, and an average particle size is about 0.90μm to 1.30μm.
Claim 7
Dependent Claim
47 words
The ceramic composition of claim 4 wherein: the niobium pentoxide has a purity of about 99.0% and a particle size of about 0.5 to 0.9μm; and the cobalt oxide has a purity of about 70% to 74% and a particle size of less than about 1.0 μm.
Claim 8
Dependent Claim
40 words
The ceramic composition of claim 3, wherein: the barium titanate is about 98.82% wt; the niobium pentoxide is about 0.98% wt; the cobalt oxide is about 0.20% wt; and the niobium pentoxide to cobalt oxide weight ratio is about 4.90.
References Cited (Backward Citations)
US4054531A
Cited
GB1527060A
Cited
JPS5815078A
Cited
JPS5828103A
Cited
JPS5920905A
Cited
JPS5963605A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1992-11-20 | 1993-05-22 | 1993-11-21 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1996-11-20 | 1997-05-22 | 1997-11-21 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2000-11-20 | 2001-05-22 | 2001-11-21 | $7700.00 | Window Closed / Lapsed |