US5953203A
Expired / Lapsed
US
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Multilayer ceramic circuit boards including embedded capacitors
Assignee: Sharp Corp
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Filing: 1997-03-06
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Granted: 1999-09-14
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Expires: 2017-03-06
Abstract
Abstract Embedded capacitors are formed in multilayer ceramic circuit boards by screen printing a capacitor ink sandwiched between conductor ink layers onto a green tape stack and covering the ink layer with one or two green tapes, and aligning the green tape layers, and firing. The green tapes are made of a mixture of a crystallizing glass, a non-crystallizing glass and an oxide filler which do not shrink in the x and y dimensions during firing. Thus the capacitors can be made to close tolerances.
Inventors
- 👤 Ellen Schwartz Tormey
- 👤 Ashok Narayan Prabhu
- 👤 Attiganal Narayanaswamy Sreeram
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-09 21:55
CPC Classifications
H; H10; H10W; H10W44/00; H01; H01C; H01C13/00; H01C13/02; H01C17/00; H01C17/30; H01C7/00; H01C7/003; H05; H05K; H05K1/00; H05K1/16; H05K1/162; H05K1/167; H05K1/02; H05K1/03; H05K1/0306; H05K1/09; H05K1/092; H05K3/00; H05K3/46; H05K3/4611; H05K3/4626; H05K3/4629; H05K3/4688; Y; Y10; Y10T; Y10T29/00; Y10T29/49; Y10T29/49002; Y10T29/49117; Y10T29/49124; Y10T29/49128
Claims Analysis
Total Claims: 23
Claim 1
Independent Claim
54 words
A supported ceramic circuit board having buried capacitors comprising a laminated green tape stack on a kovar support, a buried screen printed capacitor made from a dielectric selected from the group consisting of barium titanate and lead-magnesium niobate, a silver conductor layer printed below and above the capacitor, and an overlying green tape layer.
Claim 2
Dependent Claim
54 words
A supported ceramic circuit board having buried capacitors comprising a laminated green tape stack on a kovar support, a buried screen printed capacitor made from a dielectric selected from the group consisting of barium titanate and lead-magnesium niobate, a silver conductor layer printed below and above the capacitor, and an overlying green tape layer.
Claim 3
Dependent Claim
17 words
A supported ceramic circuit board according to claim 1 wherein said capacitor is made from barium titanate.
Claim 4
Dependent Claim
16 words
A fired ceramic circuit board of claim 2 wherein said capacitor is made from barium titanate.
Claim 5
Dependent Claim
17 words
A supported ceramic circuit board according to claim 1 wherein said capacitor is made from lead-magnesium niobate.
Claim 6
Dependent Claim
37 words
A supported ceramic circuit board according to claim 4 wherein said capacitors are sandwiched between two barium titanate barrier layers of sufficient thickness so as to prevent diffusion of glasses of the green tape into the capacitors.
Claim 7
Dependent Claim
35 words
A fired circuit board of claim 4 wherein said capacitors are sandwiched between two barium titanate barrier layers of a thickness so as to prevent diffusion of glasses of the green tape into the capacitors.
Claim 8
Dependent Claim
33 words
A capacitor ink comprising a dielectric, selected from the group consisting of barium titanate and lead-magnesium-niobate, a low firing temperature glass that includes less than 2% of barium oxides; and an organic vehicle.
Claim 9
Dependent Claim
33 words
A capacitor ink comprising a dielectric, selected from the group consisting of barium titanate and lead-magnesium-niobate, a low firing temperature glass that includes less than 2% of barium oxides; and an organic vehicle.
Claim 10
Dependent Claim
41 words
A capacitor ink according to claim 1 wherein the dielectric is barium titanate which is mixed with a low temperature firing glass that does not include barium oxide so that the firing temperature of the mixture is below about 900° C.
Claim 11
Dependent Claim
42 words
A capacitor ink according to claim 7 wherein the dielectric is lead-magnesium-niobate which is mixed with a low firing temperature glass that includes less than 2% of barium oxide so that the firing temperature of the mixture is below about 900° C.
Claim 12
Dependent Claim
104 words
A multilayer ceramic tape stack comprising a plurality of low firing temperature green tapes that do not shrink in the x and y dimensions during firing having circuit patterns screen printed thereon and mounted on a metal support substrate, capacitors screen printed from a capacitor ink comprising a dielectric, selected from the group consisting of barium titanate and lead-magnesium-niobate; a low firing temperature glass that includes less than 2% of barium oxide; and an organic vehicle on a green tape layer, conductor layers screen printed above and below the capacitors and one or two green tape layers above the conductor layers above the capacitors.
Claim 13
Dependent Claim
104 words
A multilayer ceramic tape stack comprising a plurality of low firing temperature green tapes that do not shrink in the x and y dimensions during firing having circuit patterns screen printed thereon and mounted on a metal support substrate, capacitors screen printed from a capacitor ink comprising a dielectric, selected from the group consisting of barium titanate and lead-magnesium-niobate; a low firing temperature glass that includes less than 2% of barium oxide; and an organic vehicle on a green tape layer, conductor layers screen printed above and below the capacitors and one or two green tape layers above the conductor layers above the capacitors.
Claim 14
Dependent Claim
22 words
A green tape stack according to claim 10 wherein said capacitors are of barium titanate and said conductor layers are of silver.
Claim 15
Dependent Claim
24 words
A green tape stack according to claim 11 wherein said silver conductor layers are made from a mixture of silver powder and silver flake.
Claim 16
Dependent Claim
15 words
A green tape stack according to claim 10 wherein said capacitors are of lead-magnesium niobate.
Claim 17
Dependent Claim
38 words
A green tape stack according to claim 13 wherein said capacitors are sandwiched between two barium titanate barrier layers, each having a thickness that prevents diffusion of the glasses of the green tape into the capacitors during firing.
Claim 18
Dependent Claim
16 words
A green tape stack according to claim 14 wherein said thickness is at least 16 microns.
Claim 19
Dependent Claim
23 words
A green tape stack according to claim 13 wherein said conductor layer is made from a mixture of silver powder and silver flake.
Claim 20
Dependent Claim
115 words
A multilayer ceramic tape stack comprising a plurality of low firing temperature green tapes that do not shrink in the x and y dimensions during firing having circuit patterns screen printed thereon and mounted on a metal support substrate, capacitors screen printed from a capacitor ink comprising a dielectric, selected from the group consisting of barium titanate and lead-magnesium-niobate; a low firing temperature glass that includes less than 2% of barium oxide; and an organic vehicle on a green tape layer, conductor layers screen printed above and below the capacitors and one or two green tape layers above the conductor layers above the capacitors, wherein said metal support substrate is made of a ferro/nickel/cobalt/manganese alloy.
Claim 21
Dependent Claim
115 words
A multilayer ceramic tape stack comprising a plurality of low firing temperature green tapes that do not shrink in the x and y dimensions during firing having circuit patterns screen printed thereon and mounted on a metal support substrate, capacitors screen printed from a capacitor ink comprising a dielectric, selected from the group consisting of barium titanate and lead-magnesium-niobate; a low firing temperature glass that includes less than 2% of barium oxide; and an organic vehicle on a green tape layer, conductor layers screen printed above and below the capacitors and one or two green tape layers above the conductor layers above the capacitors, wherein said metal support substrate is made of a ferro/nickel/cobalt/manganese alloy.
Claim 22
Dependent Claim
54 words
A fired ceramic circuit board having buried capacitors comprising a laminated green tape stack on a kovar support, a buried screen printed capacitor made from a dielectric selected from the group consisting of barium titanate and lead-magnesium niobate, a silver conductor layer printed below and above the capacitor, and an overlying green tape layer.
Claim 23
Dependent Claim
54 words
A fired ceramic circuit board having buried capacitors comprising a laminated green tape stack on a kovar support, a buried screen printed capacitor made from a dielectric selected from the group consisting of barium titanate and lead-magnesium niobate, a silver conductor layer printed below and above the capacitor, and an overlying green tape layer.
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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) | 2002-09-13 | 2003-03-15 | 2003-09-14 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 2006-09-13 | 2007-03-15 | 2007-09-14 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2010-09-13 | 2011-03-15 | 2011-09-14 | $7700.00 | Window Closed / Lapsed |