US5216207A
Expired / Lapsed
US
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Low temperature co-fired multilayer ceramic circuit boards with silver conductors
Assignee: Sumitomo Metal Mining Co Ltd
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Filing: 1991-02-27
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Granted: 1993-06-01
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Expires: 2011-02-27
Abstract
Abstract A novel ceramic green tape composition useful in the manufacture of silver conductor based, low temperature, co-fired multilayer circuit boards comprises from about 8-35% by weight of a calcium-zinc-aluminum-borosilicate devitrifying glass; from about 10-35% by weight of a low alkali borosilicate glass; from about 10-35% by weight of a lead-zinc-aluminosilicate glass; from about 10-35% by weight of a ceramic filler; up to 0.5% by weight of a coloring agent and from about 20-45% by weight of an organic binder. The co-fired multilayer circuit boards made from these green tape compositions have excellent mechanical and electrical properties and have thermal expansion characteristics matching that of silicon. The devitrifying glass comprises from about 10-30% by weight of zinc oxide; from about 10-20% by weight of calcium oxide; up to about 15% by weight of boron oxide; from about 15-20% by weight of aluminum oxide and about 25-55% by weight of silicon oxide. The lead-zinc-aluminosilicate vitreous glass comprises from about 30-40% by weight of lead oxide, from about 6-12% by weight of zinc oxide, from about 6-10% by weight of aluminum oxide and from about 40-55% by weight of silicon oxide. Conductor inks can also be made from the above glasses, and mixtures thereof together with a suitable organic vehicle and a conductive metal such as silver.
Inventors
- 👤 Ashok N. Prabhu
- 👤 Edward J. Conlon
- 👤 Barry J. Thaler
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-08 17:21
CPC Classifications
H; H05; H05K; H05K1/00; H05K1/02; H05K1/03; H05K1/0306; C; C03; C03C; C03C14/00; C03C14/004; H10; H10W; H10W70/00; H10W70/60; H10W70/67; H10W70/69; H10W70/692; C03C2214/00; C03C2214/04; C03C2214/20
Claims Analysis
Total Claims: 22
Claim 1
Independent Claim
99 words
In a low temperature co-fired multilayer ceramic circuit board comprising two or more patterned conductor layers of a conductive metal selected from the group consisting of silver, gold, copper, palladium and platinum and mixtures thereof in a glass matrix, said layers being separated by a dielectric layer having vias therein filled with conductive material to contact said conductive layers for connection to said conductive metal layers, the improvement which comprises employing as said dielectric layer a composition comprising a combination of a calcium-zinc-aluminum-borosilicate devitrifying glass, a low alkali borosilicate vitreous glass, a lead-zinc-aluminosilicate vitreous glass and a ceramic filler.
Claim 2
Dependent Claim
99 words
In a low temperature co-fired multilayer ceramic circuit board comprising two or more patterned conductor layers of a conductive metal selected from the group consisting of silver, gold, copper, palladium and platinum and mixtures thereof in a glass matrix, said layers being separated by a dielectric layer having vias therein filled with conductive material to contact said conductive layers for connection to said conductive metal layers, the improvement which comprises employing as said dielectric layer a composition comprising a combination of a calcium-zinc-aluminum-borosilicate devitrifying glass, a low alkali borosilicate vitreous glass, a lead-zinc-aluminosilicate vitreous glass and a ceramic filler.
Claim 3
Dependent Claim
56 words
A multilayer ceramic circuit board according to claim 1 wherein the devitrifying glass comprises from about 10-30% by weight of zinc oxide, from about 10-20% by weight of calcium oxide, up to about 15% by weight of boron oxide, from about 15-20% by weight of aluminum oxide and from about 25-55% by weight of silicon oxide.
Claim 4
Dependent Claim
48 words
A multilayer ceramic circuit board according to claim 1 wherein the lead-zinc-aluminosilicate vitreous glass comprises from about 30-40% by weight of lead oxide, from about 6-12% by weight of zinc oxide, from about 6-10% by weight of aluminum oxide and from about 40-55% by weight of silicon oxide.
Claim 5
Dependent Claim
15 words
A multilayer ceramic circuit board according to claim 1 wherein said conductive metal is silver.
Claim 6
Dependent Claim
25 words
A multilayer ceramic circuit board according to claim 1 wherein said ceramic filler is selected from the group consisting of alumina, zircon and zirconium oxide.
Claim 7
Dependent Claim
58 words
A conductor ink for multilayer integrated circuit boards comprising a glass composition and a conductive metal selected from the group consisting of silver, gold, copper, palladium, platinum and mixtures thereof in an organic vehicle, wherein said glass composition comprises a calcium-zinc-aluminum-borosilicate devitrifying glass composition, a low alkali borosilicate vitreous glass, a lead-zinc-aluminosilicate vitreous glass and a ceramic filler.
Claim 8
Dependent Claim
58 words
A conductor ink for multilayer integrated circuit boards comprising a glass composition and a conductive metal selected from the group consisting of silver, gold, copper, palladium, platinum and mixtures thereof in an organic vehicle, wherein said glass composition comprises a calcium-zinc-aluminum-borosilicate devitrifying glass composition, a low alkali borosilicate vitreous glass, a lead-zinc-aluminosilicate vitreous glass and a ceramic filler.
Claim 9
Dependent Claim
54 words
A conductor ink according to claim 6 wherein the devitrifying glass comprises from about 10-30% by weight of zinc oxide, from about 10-20% by weight of calcium oxide, up to about 15% by weight of boron oxide, from about 15-20% by weight of aluminum oxide and from about 25-55% by weight of silicon oxide.
Claim 10
Dependent Claim
46 words
A conductor ink according to claim 6 wherein the lead-zinc-aluminosilicate vitreous glass comprises from about 30-40% by weight of lead oxide, from about 6-12% by weight of zinc oxide, from about 6-10% by weight of aluminum oxide and from about 40-55% by weight of silicon oxide.
Claim 11
Dependent Claim
13 words
A conductor ink according to claim 6 wherein said conductive metal is silver.
Claim 12
Dependent Claim
25 words
A conductor ink according to claim 6 wherein said ceramic filler is selected from the group consisting of alumina, zircon, zirconium oxide and zinc silicate.
Claim 13
Dependent Claim
30 words
A green tape composition comprising a combination of a calcium-zinc-aluminum-borosilicate devitrifying glass, a low alkali borosilicate vitreous glass, a lead-zinc-aluminosilicate vitreous glass and a ceramic filler in an organic vehicle.
Claim 14
Dependent Claim
30 words
A green tape composition comprising a combination of a calcium-zinc-aluminum-borosilicate devitrifying glass, a low alkali borosilicate vitreous glass, a lead-zinc-aluminosilicate vitreous glass and a ceramic filler in an organic vehicle.
Claim 15
Dependent Claim
13 words
A green tape composition according to claim 11 additionally containing a coloring agent.
Claim 16
Dependent Claim
69 words
A green tape composition according to claim 11 comprising from about 8-35% by weight of a devitrifying glass, from about 10-35% by weight of a low alkali borosilicate vitreous glass, from about 10-35% by weight of a lead-zinc-aluminosilicate vitreous glass, from about 10-35% by weight of a ceramic filler, up to about 0.5% by weight of a coloring agent and from about 20-45% by weight of an organic binder.
Claim 17
Dependent Claim
55 words
A green tape composition according to claim 11 wherein the devitrifying glass comprises from about 10-30% by weight of zinc oxide, from about 10-20% by weight of calcium oxide, up to about 15% by weight of boron oxide, from about 15-20% by weight of aluminum oxide and from about 25-55% by weight of silicon oxide.
Claim 18
Dependent Claim
47 words
A green tape composition according to claim 11 wherein said lead-zinc-aluminosilicate vitreous glass comprises from about 30-40% by weight of lead oxide, from about 6-12% by weight of zinc oxide, from about 6-10% by weight of aluminum oxide and from about 40-55% by weight of silicon oxide.
Claim 19
Dependent Claim
26 words
A green tape composition according to claim 11 wherein said ceramic filler is selected from the group consisting of alumina, zircon, zirconium oxide and zinc silicate.
Claim 20
Dependent Claim
36 words
A green tape composition according to claim 11 wherein said organic vehicle is a combination of a polyvinyl butyral resin, an alkyl benzyl phthalate plasticizer, ethanol and methyl ethyl ketone solvents and a fish oil surfactant.
Claim 21
Dependent Claim
44 words
A devitrifying glass composition comprising the following oxides on a weight basis: from about 10-30% of zinc oxide, from about 10-20% of calcium oxide, up to about 15% of boron oxide, from about 15-20% of aluminum oxide and from about 25-55% of silicon oxide.
Claim 22
Dependent Claim
44 words
A devitrifying glass composition comprising the following oxides on a weight basis: from about 10-30% of zinc oxide, from about 10-20% of calcium oxide, up to about 15% of boron oxide, from about 15-20% of aluminum oxide and from about 25-55% of silicon oxide.
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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) | 1996-05-31 | 1996-11-30 | 1997-06-01 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 2000-05-31 | 2000-11-30 | 2001-06-01 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2004-05-31 | 2004-11-30 | 2005-06-01 | $7700.00 | Window Closed / Lapsed |