US3977887A
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High dielectric constant ceramics which can be sintered at low temperatures
Assignee: International Business Machines Corp
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Filing: 1974-03-08
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Granted: 1976-08-31
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Expires: 1994-03-08
Abstract
Abstract The present invention relates to high dielectric constant ceramics which can be sintered to maximum density at low temperatures. The ceramic structures consist primarily of a skeleton which constitutes the refractory phase and an interstitial glass which serves simultaneously as a bonding agent and a fluxing agent which enables the ceramic structure to densify in the low temperature range. Among the preferred materials used to form the skeleton are polycrystalline materials which have a high dielectric constant, for example, barium titanate, complex dielectric materials such as lead bismuth niobate and the like. The interstitial glasses required are lead silicate based glasses.
Inventors
- 👤 Charles M. McIntosh
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-28 14:35
CPC Classifications
C; C04; C04B; C04B35/00; C04B35/622; C04B35/626; C04B35/63; C04B35/632; C04B35/634; C04B35/63404; C04B35/6342; C04B35/01; C04B35/46; C04B35/462; C04B35/465; C04B35/468; C04B35/4682; C04B35/63424; H; H01; H01B; H01B3/00; H01B3/02; H01B3/025; H01G; H01G4/00; H01G4/002; H01G4/018; H01G4/06; H01G4/08; H01G4/12; H01G4/129
Claims Analysis
Total Claims: 17
Claim 1
Independent Claim
100 words
A high dielectric constant ceramic body which is non-porous by the Zyglo dye test and 0% porous by the water absorption test, which has been sintered at a temperature of from about 850°C to about 950°C to densify said body, which consists essentially of a major portion of a polycrystalline ceramic refractory material and a lead silicate based interstitial glass selected from the glasses from the binary system PbO-SiO 2 the ternary system PbO-Al 2 O 3 -SiO 2 and the ternary system PbO-ZrO 2 -SiO 2 and which has a dielectric constant of from about 230 to about 550.
Claim 2
Dependent Claim
100 words
A high dielectric constant ceramic body which is non-porous by the Zyglo dye test and 0% porous by the water absorption test, which has been sintered at a temperature of from about 850°C to about 950°C to densify said body, which consists essentially of a major portion of a polycrystalline ceramic refractory material and a lead silicate based interstitial glass selected from the glasses from the binary system PbO-SiO 2 the ternary system PbO-Al 2 O 3 -SiO 2 and the ternary system PbO-ZrO 2 -SiO 2 and which has a dielectric constant of from about 230 to about 550.
Claim 3
Dependent Claim
25 words
The sintered high dielectric constant ceramic body of claim 1 wherein said glass comprises less than about 1/3 of the weight of said refractory material.
Claim 4
Dependent Claim
29 words
The sintered high dielectric constant ceramic body of claim 1 wherein said glass comprises from about 20 to about 30 wt. % of said glass plus said refractory material.
Claim 5
Dependent Claim
25 words
The sintered high dielectric constant ceramic body of claim 1 wherein said refractory material has a dielectric constant of from about 1100 to about 1500.
Claim 6
Dependent Claim
20 words
The sintered high dielectric constant ceramic body of claim 1 wherein said refractory material coprises a titanate or a zirconate.
Claim 7
Dependent Claim
38 words
The sintered high dielectric constant ceramic body of claim 1 wherein said refractory material is selected from the group consisting of barium titanate, lead zirconium titanate, lead bismuth niobate-barium titanate, bismuth zirconate, bismuth titanate or a blend thereof.
Claim 8
Dependent Claim
41 words
The sintered high dielectric constant ceramic body of claim 1 wherein said lead silicate based glass is selected from the group consisting of tribasic lead silicate, lead monosilicate, lead alumina bisilicate, eutectic lead bisilicate, lead zirconium silicate or a blend thereof.
Claim 9
Dependent Claim
19 words
The sintered high dielectric constant ceramic body of claim 1 wherein a single polycrystalline ceramic refractory material is present.
Claim 10
Dependent Claim
20 words
The sintered high dielectric constant ceramic body of claim 8 wherein said single polycrystalline ceramic refractory material is barim titanate.
Claim 11
Dependent Claim
21 words
The sintered high dielectric constant ceramic body of claim 8 wherein said single polycrystalline ceramic refractory material is lead zirconium titanate.
Claim 12
Dependent Claim
22 words
The sintered high dielectric constant ceramic body of claim 8 wherein said single polycrystalline ceramic refractory material is lead bismuth niobate-barium titanate.
Claim 13
Dependent Claim
20 words
The sintered high dielectric constant ceramic body of claim 8 wherein said single polycrystalline ceramic refractory material is bismuth zirconate.
Claim 14
Dependent Claim
20 words
The sintered high dielectric constant ceramic body of claim 8 wherein said single polycrystalline ceramic refractory material is bismuth titanate.
Claim 15
Dependent Claim
21 words
The sintered high dielectric constant ceramic body of claim 1 which consists of said polycrystalline ceramic refractory material and said glass.
Claim 16
Dependent Claim
21 words
The sintered high dielectric constant ceramic body of claim 8 which consists of said polycrystalline ceramic refractory material and said glass.
Claim 17
Dependent Claim
22 words
The sintered high dielectric constant ceramic body of claim 1 which contains at least 11.79 % by weight lead, expressed as PbO.
References Cited (Backward Citations)
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1979-08-31 | 1980-03-01 | 1980-08-31 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1983-08-31 | 1984-03-01 | 1984-08-31 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1987-08-31 | 1988-03-01 | 1988-08-31 | $7700.00 | Window Closed / Lapsed |