US4101952A
Expired / Lapsed
US
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Monolithic base-metal glass-ceramic capacitor
Assignee: MRA Laboratories Inc
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Filing: 1976-08-17
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Granted: 1978-07-18
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Expires: 1996-08-17
Abstract
Abstract A monolithic ceramic capacitor has base-metal electrodes buried in a high dielectric constant reduction resistant glass-ceramic body. The glass component is an alkaline earth aluminoborate glass. The ceramic component is a barium titanate. The capacitor body is sintered at from 950° C to 1080° C in a low partial oxygen atmosphere. The buried electrode may be elementary copper.
Inventors
- 👤 Ian Burn
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-29 08:55
CPC Classifications
H; H01; H01G; H01G4/00; H01G4/002; H01G4/018; H01G4/06; H01G4/08; H01G4/12; C; C04; C04B; C04B35/00; C04B35/01; C04B35/46; C04B35/462; C04B35/465; C04B35/468; C04B35/4682; H01G4/005; H01G4/008; H01G4/0085
Claims Analysis
Total Claims: 25
Claim 1
Independent Claim
148 words
A monolithic ceramic capacitor comprising: a reduction resistant glass-ceramic body having at room temperature a dielectric constant greater than 1000 and having a characteristic sintering and full densification temperature of from 1080° C to 950° C, said body consisting of from 5 to 15% by weight of a non-crystalline glass phase and from 85 to 95 percent by weight of a crystalline ceramic phase having a characteristic sintering and densification temperature greater than about 1200° C, said glass phase consisting essentially of an alkaline earth aluminoborate glass wherein said alkaline earth is selected from barium, strontium and calcium, said crystalline phase being an alkaline earth metal titanate wherein at least 50 mole percent of said alkaline earth metal is barium; a base metal electrode being buried within said reduction resistant glass-ceramic body; and another metal electrode contacting said body and being in capacitive relationship with said buried electrode.
Claim 2
Dependent Claim
148 words
A monolithic ceramic capacitor comprising: a reduction resistant glass-ceramic body having at room temperature a dielectric constant greater than 1000 and having a characteristic sintering and full densification temperature of from 1080° C to 950° C, said body consisting of from 5 to 15% by weight of a non-crystalline glass phase and from 85 to 95 percent by weight of a crystalline ceramic phase having a characteristic sintering and densification temperature greater than about 1200° C, said glass phase consisting essentially of an alkaline earth aluminoborate glass wherein said alkaline earth is selected from barium, strontium and calcium, said crystalline phase being an alkaline earth metal titanate wherein at least 50 mole percent of said alkaline earth metal is barium; a base metal electrode being buried within said reduction resistant glass-ceramic body; and another metal electrode contacting said body and being in capacitive relationship with said buried electrode.
Claim 3
Dependent Claim
19 words
The monolithic capacitor of claim 1 wherein said base metal is selected from copper, nickel, cobalt and alloys thereof.
Claim 4
Dependent Claim
14 words
The monolithic capacitor of claim 2 wherein said base metal consists essentially of copper.
Claim 5
Dependent Claim
18 words
The monolithic capacitor of claim 1 wherein said alkaline earth of said glass is partially replaced by magnesium.
Claim 6
Dependent Claim
24 words
The monolithic capacitor of claim 1 wherein an alkali-metal is substituted for up to 50 mole percent of said alkaline earth of said glass.
Claim 7
Dependent Claim
22 words
The monolithic capacitor of claim 1 wherein zirconium is substituted for up to 20 mole percent of the titanium of said titanate.
Claim 8
Dependent Claim
30 words
The monolithic capacitor of claim 1 wherein said titanate phase consists essentially of from 50 to 75 mole percent barium titanate and from 25 to 50 mole percent strontium titanate.
Claim 9
Dependent Claim
24 words
The monolithic capacitor of claim 1 wherein the said alkaline earth metal of said titanate is replaced by up to 8 mole percent calcium.
Claim 10
Dependent Claim
31 words
The monolithic capacitor of claim 1 wherein said alkaline earth metal titanate consists essentially of 60 mole percent barium titanate, 32.2 mole percent strontium titanate and 7.8 mole percent calcium titanate.
Claim 11
Dependent Claim
19 words
The monolithic capacitor of claim 1 wherein said glass phase includes no more than about 1 mole percent silica.
Claim 12
Independent Claim
139 words
A method for making a monolithic ceramic capacitor having a reduction resistant glass-ceramic body exhibiting a dielectric constant at room temperature greater than 1000 and having a buried base metal electrode comprising: (a) preparing a slip consisting of a glass powder, a precursor powder of a crystalline ceramic material and a binder medium, said glass consisting essentially of an alkaline earth aluminoborate glass wherein said alkaline earth is selected from barium, strontium and calcium, said at least one ceramic material having a characteristic sintering and densification temperature greater than 1200° C, said ceramic material being a titanate of alkaline earth metal wherein at least 50 mole percent of said alkaline earth metal is barium, said glass powder being from 5-15% by weight of said glass and said ceramic powders combined; (b) forming a plurality of layers of said slip;
Claim 13
Independent Claim
139 words
A method for making a monolithic ceramic capacitor having a reduction resistant glass-ceramic body exhibiting a dielectric constant at room temperature greater than 1000 and having a buried base metal electrode comprising: (a) preparing a slip consisting of a glass powder, a precursor powder of a crystalline ceramic material and a binder medium, said glass consisting essentially of an alkaline earth aluminoborate glass wherein said alkaline earth is selected from barium, strontium and calcium, said at least one ceramic material having a characteristic sintering and densification temperature greater than 1200° C, said ceramic material being a titanate of alkaline earth metal wherein at least 50 mole percent of said alkaline earth metal is barium, said glass powder being from 5-15% by weight of said glass and said ceramic powders combined; (b) forming a plurality of layers of said slip;
Claim 14
Dependent Claim
142 words
(c) preparing an electroding base metal paste comprised of base metal particles and a binder medium and applying a coating of said paste to a surface of at least one of said layers; (d) stacking at least two of said layers so as to bury within said stack said electroding base metal coating of said at least one layer; (e) heating said stack with said buried base metal coating at a temperature of from 1080° C to 950° C in an atmosphere of partial oxygen pressure less than 3×10 -6 atmospheres to sinter and fully densify said glass-ceramic stack, and to fire said buried coating to form a buried base metal electrode within said sintered capacitor body; and (f) applying to said stack another metal coating in spaced relationship to said buried electrode to serve as a second electrode of said capacitor.
Claim 15
Dependent Claim
142 words
(c) preparing an electroding base metal paste comprised of base metal particles and a binder medium and applying a coating of said paste to a surface of at least one of said layers; (d) stacking at least two of said layers so as to bury within said stack said electroding base metal coating of said at least one layer; (e) heating said stack with said buried base metal coating at a temperature of from 1080° C to 950° C in an atmosphere of partial oxygen pressure less than 3×10 -6 atmospheres to sinter and fully densify said glass-ceramic stack, and to fire said buried coating to form a buried base metal electrode within said sintered capacitor body; and (f) applying to said stack another metal coating in spaced relationship to said buried electrode to serve as a second electrode of said capacitor.
Claim 16
Dependent Claim
28 words
The method of claim 11 wherein, at the particular temperature of said heating, said partial oxygen pressure is less than that required for metal to metal-oxide thermodynamic equilibrium.
Claim 17
Dependent Claim
47 words
The method of claim 11 additionally comprising applying a film of said base metal paste to a face of said stack and in contact with an edge of said at least one electroding coating prior to said heating to provide an electrical termination to said buried electrode.
Claim 18
Dependent Claim
18 words
The method of claim 11 wherein said base metal is selected from copper, nickel, cobalt and alloys thereof.
Claim 19
Dependent Claim
13 words
The method of claim 11 wherein said base metal consists essentially of copper.
Claim 20
Dependent Claim
27 words
The method of claim 15 wherein said temperature of said heating is about 1050° C and said partial oxygen pressure is about 3×10 -6 atmospheres of oxygen.
Claim 21
Dependent Claim
17 words
The method of claim 11 wherein said alkaline earth of said glass is partially replaced by magnesium.
Claim 22
Dependent Claim
24 words
The method of claim 11 wherein an alkali metal is substituted for up to 50 mole percent of said alkaline earth of said glass.
Claim 23
Dependent Claim
21 words
The method of claim 11 wherein zirconium is substituted for up to 20 mole percent of the titanium of said titanate.
Claim 24
Dependent Claim
28 words
The method of claim 11 wherein said titanate consists essentially of from 50 to 75 mole percent barium titanate and from 25 to 50 mole percent strontium titanate.
Claim 25
Dependent Claim
30 words
The method of claim 11 wherein said alkaline earth metal titanate consists essentially of 60 mole percent barium titanate, 32.2 mole percent strontium titanate and 7.8 mole percent calcium titanate.
References Cited (Backward Citations)
US3763409A
Cited
US3902102A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1981-07-17 | 1982-01-16 | 1982-07-18 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1985-07-17 | 1986-01-16 | 1986-07-18 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1989-07-17 | 1990-01-16 | 1990-07-18 | $7700.00 | Window Closed / Lapsed |