US4904415A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Oxide glasses having low glass transformation temperatures
Assignee: WR Grace and Co Conn
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Filing: 1988-08-22
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Granted: 1990-02-27
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Expires: 2008-08-22
Abstract
Abstract PbO-B 2 O 3 -Ag 2 O glasses having a preferred weight ratio range of 76-88:10-15:2-10 have glass transition temperatures of less than 300° C. and are especially useful for adhering together ceramic substrates such as for attaching integrated circuits to ceramic substrates. The glasses can be formulated with Ag particulates and organics and applied as pastes to provide conductive adhesives.
Inventors
- 👤 John W. Lau
- 👤 Anastasia M. Conlon
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-03 21:01
CPC Classifications
C; C03; C03C; C03C3/00; C03C3/12; C03C3/14; C03C3/142; C03C8/00; C03C8/14; C03C8/18; C03C8/24; C03C8/245; C04; C04B; C04B37/00; C04B37/003; C04B37/005; C22; C22C; C22C32/00; C22C32/0089; C04B2237/00; C04B2237/02; C04B2237/10; C04B2237/30; C04B2237/32; C04B2237/34; C04B2237/341; C04B2237/343; C04B2237/36; C04B2237/365; C04B2237/368
Claims Analysis
Total Claims: 17
Claim 1
Independent Claim
53 words
A homogeneous composition suitable for use in forming a conductive adhesive comprising a powdered glass composition having a glass transformation temperature below about 300° C., comprising PbO, B 2 O 3 , and Ag 2 O in a respective weight ratio of 76-88:10-15:2-10 and conductive particulates present in an electrically conductive effective amount.
Claim 2
Dependent Claim
53 words
A homogeneous composition suitable for use in forming a conductive adhesive comprising a powdered glass composition having a glass transformation temperature below about 300° C., comprising PbO, B 2 O 3 , and Ag 2 O in a respective weight ratio of 76-88:10-15:2-10 and conductive particulates present in an electrically conductive effective amount.
Claim 3
Dependent Claim
42 words
A homogeneous composition according to claim 1 comprising said powdered glass having a particle size which passes through a 200 U.S. mesh screen, but being not less than about 2 microns and Ag particulates, in a glass:Ag weight ratio of about 1:2.3-7.3.
Claim 4
Dependent Claim
13 words
A homogeneous composition according to claim 2, wherein the ratio is about 1:3-5.7.
Claim 5
Dependent Claim
104 words
A homogeneous composition according to claim 1 comprising said powdered glass and Ag particles, in a glass:Ag weight ratio of 1:3-5.7; said Ag particles consisting essentially of a mixture of components A and B; component A being Ag particles having an average size of about 9 microns, with about 90 weight % less than 15 microns and about 10% less than 4 microns; component B being Ag particles having an average size of about 3.5 microns, with about 90 weight % less than 11 microns and about 10 weight % less than 0.7 micron; and the weight ratio of components A:B is about 3-6:1.
Claim 6
Dependent Claim
24 words
A conductive adhesive composition according to claim 4, wherein the glass:Ag weight ratio is 1:4; and the ratio of components A:B is about 4:1.
Claim 7
Dependent Claim
21 words
A composition comprising the composition of claim 1 and further comprising an organic binder so as to form a paste composition.
Claim 8
Dependent Claim
21 words
A composition comprising the composition of claim 2 and further comprising an organic binder so as to form a paste composition.
Claim 9
Dependent Claim
21 words
A composition comprising the composition of claim 3 and further comprising an organic binder so as to form a paste composition.
Claim 10
Dependent Claim
21 words
A composition comprising the composition of claim 4 and further comprising an organic binder so as to form a paste composition.
Claim 11
Dependent Claim
21 words
A composition comprising the composition of claim 5 and further comprising an organic binder so as to form a paste composition.
Claim 12
Dependent Claim
46 words
An electrically conductive paste composition comprising (A) 11-23 weight % powdered glass, said glass comprising PbO, B 2 O 3 , and Ag 2 O in a respective weight ratio of 76-88:10-15:2-10; (B) 56-77 weight % conductive metal particulates; (C) 10-25 weight % organic, including solvent.
Claim 13
Dependent Claim
46 words
An electrically conductive paste composition comprising (A) 11-23 weight % powdered glass, said glass comprising PbO, B 2 O 3 , and Ag 2 O in a respective weight ratio of 76-88:10-15:2-10; (B) 56-77 weight % conductive metal particulates; (C) 10-25 weight % organic, including solvent.
Claim 14
Dependent Claim
24 words
A paste composition according to claim 11, wherein: (A) is 15-19 weight %; (B) is 65-70 weight %; and (C) is 13-17 weight %.
Claim 15
Dependent Claim
83 words
A paste composition according to claim 12, wherein (B) is Ag consisting of a homogeneous blend of (I) Ag particles having an average size of about 9 microns, with about 90 weight % less than 15 microns and then about 10% less than 4 microns, and (II) Ag particles having an average size of about 3.5 microns, with about 90 weight % less than 11 microns and about 10 weight % less than 0.7 microns; the weight ratio of I:II being about 3-6:1.
Claim 16
Dependent Claim
12 words
A paste composition according to claim 13, wherein I:II is about 4:1.
Claim 17
Dependent Claim
56 words
A homogeneous composition according to claim 4, where said glass consisting essentially of, in weight %, PbO 83.71%; B 2 O 3 11.45%; Al 2 O 3 0.29%; ZnO 1.88%; and Ag 2 O 2.67% and having a particle size which passes through a 200 U.S. mesh screen, but being not less than about 2 microns.
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) | 1993-02-26 | 1993-08-28 | 1994-02-27 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1997-02-26 | 1997-08-28 | 1998-02-27 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2001-02-26 | 2001-08-28 | 2002-02-27 | $7700.00 | Window Closed / Lapsed |