US4761224A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Silver-glass paste with poly-modal flake size distribution and quick dry vehicle
Assignee: Henkel Loctite Corp
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Filing: 1987-01-08
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Granted: 1988-08-02
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Expires: 2007-01-08
Abstract
Abstract A silver glass paste consists of 60-75% silver flake having a tap density greater than 2.8 gm/cc and less than 5.0 gm/cc. The silver flake has a poly-modal flake size distribution. The paste further consists of 12-20% glass frit, 0.5-2% of a suitable organic resin and 8-20% of a suitable organic solvent. The resin may be acrylic and the organic solvent may be an ester alcohol or an ester alcohol mixed with a glycol ether or glycol ether ester.
Inventors
- 👤 Frank D. Husson, Jr.
- 👤 Kathleen E. Walter
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-04 14:22
CPC Classifications
C; C03; C03C; C03C8/00; C03C8/14; C03C8/18
Claims Analysis
Total Claims: 22
Claim 1
Independent Claim
98 words
A paste for attaching a silicon die to a ceramic substrate, the paste consisting of: approximately 60 to 75% silver flake having a tap density between approximately 2.8 and 5.0 g/cc, the silver flake having a poly-modal flake size distribution with a larger flake size and a smaller flake size, the ratio of the larger flake to the smaller flake being approximately ten to one or less by weight: approximately 12 to 20% glass frit having a softening point of less that 400 degrees C.; approximately 0.5 to 2% organic resin; and approximately 8 to 20% organic solvent.
Claim 2
Dependent Claim
98 words
A paste for attaching a silicon die to a ceramic substrate, the paste consisting of: approximately 60 to 75% silver flake having a tap density between approximately 2.8 and 5.0 g/cc, the silver flake having a poly-modal flake size distribution with a larger flake size and a smaller flake size, the ratio of the larger flake to the smaller flake being approximately ten to one or less by weight: approximately 12 to 20% glass frit having a softening point of less that 400 degrees C.; approximately 0.5 to 2% organic resin; and approximately 8 to 20% organic solvent.
Claim 3
Dependent Claim
12 words
A paste according to claim 1 wherein the organic resin is acrylic.
Claim 4
Dependent Claim
14 words
A paste according to claim 2 wherein the solvent consists of an ester alcohol.
Claim 5
Dependent Claim
21 words
A paste according to claim 1 wherein the solvent consists of a mixture of an ester alcohol and a glycol ether.
Claim 6
Dependent Claim
20 words
A paste according to claim 1 wherein the solvent consists of a mixture of ester alcohol and glycol ether ester.
Claim 7
Dependent Claim
16 words
A paste according to claim 5 wherein the glycol ether ester is dipropyleneglycol monomethyl ether acetate.
Claim 8
Dependent Claim
15 words
A paste according to claim 1 wherein the resin consists of a methyl methacrylate polymer.
Claim 9
Dependent Claim
14 words
A paste according to claim 1 wherein the glass is a lead borate glass.
Claim 10
Dependent Claim
22 words
A paste according to claim 1 wherein the glass frit has a surface area of approximately 0.8 to 1.2 m 2 /g.
Claim 11
Dependent Claim
18 words
A paste according to claim 1 wherein the resin consists of two different molecular weight methyl methacrylate polymers.
Claim 12
Dependent Claim
26 words
A paste according to claim 1 wherein the ratio of the larger to smaller silver flake sizes is approximately six and one-half to one by weight.
Claim 13
Dependent Claim
91 words
A paste for attaching a silicon die to a ceramic substrate, the paste consisting of: approximately 60-75% silver flake having a tap density between approximately 2.8 and 5.0 g/cc; approximately 12 to 20% glass frit having a softening temperature of less than 400 degrees C.; approximately 0.5 to 2% acrylic resin; and approximately 8 to 20% of an organic solvent selected from the group consisting of an ester alcohol, a mixture of an ester alcohol and a glycol ether and a mixture of an ester alcohol and a glycol ether ester.
Claim 14
Dependent Claim
91 words
A paste for attaching a silicon die to a ceramic substrate, the paste consisting of: approximately 60-75% silver flake having a tap density between approximately 2.8 and 5.0 g/cc; approximately 12 to 20% glass frit having a softening temperature of less than 400 degrees C.; approximately 0.5 to 2% acrylic resin; and approximately 8 to 20% of an organic solvent selected from the group consisting of an ester alcohol, a mixture of an ester alcohol and a glycol ether and a mixture of an ester alcohol and a glycol ether ester.
Claim 15
Dependent Claim
16 words
A paste according to claim 12 wherein the silver flake has a poly-modal flake size distribution.
Claim 16
Dependent Claim
41 words
A paste according to claim 13 wherein the silver flake has at least two types of flake including a larger size and a smaller size, the ratio of the larger size flakes, by weight, being approximately ten to one or less.
Claim 17
Dependent Claim
14 words
A paste according to claim 12 wherein the glass is a lead borate glass.
Claim 18
Dependent Claim
22 words
A paste according to claim 12 wherein the glass frit has a surface area of approximately 0.8 to 1.2 m 2 /g.
Claim 19
Dependent Claim
16 words
A paste according to claim 12 wherein the glycol ether ester is dipropyleneglycol monomethyl ether acetate.
Claim 20
Dependent Claim
25 words
A paste according to claim 14 wherein the ratio of the larger to smaller flake sizes is approximately six and one-half to one by weight.
Claim 21
Dependent Claim
142 words
A paste for attaching a silicon die to a ceramic substrate, the paste consisting of: approximately 60 to 75% silver flake having a tap density between approximately 2.8 and 5.0 g/cc, the silver flake having a poly-modal flake size distribution with a larger flake size and a smaller flake size, the ratio of the larger flake to the smaller flake being approximately ten to one or less by weight; approximately 12 to 20% lead borate glass frit having surface area of approximately 0.8 to 1.2 m 2 /g and a softening point below 400 degrees C.; approximately 0.5 to 2% methyl methacrylate resin; and approximately 8 to 20% of an organic solvent selected from the group consisting of ester alcohol, a mixture of an ester alcohol and a glycol ether and a mixture of an ester alcohol and a glycol ether ester.
Claim 22
Dependent Claim
142 words
A paste for attaching a silicon die to a ceramic substrate, the paste consisting of: approximately 60 to 75% silver flake having a tap density between approximately 2.8 and 5.0 g/cc, the silver flake having a poly-modal flake size distribution with a larger flake size and a smaller flake size, the ratio of the larger flake to the smaller flake being approximately ten to one or less by weight; approximately 12 to 20% lead borate glass frit having surface area of approximately 0.8 to 1.2 m 2 /g and a softening point below 400 degrees C.; approximately 0.5 to 2% methyl methacrylate resin; and approximately 8 to 20% of an organic solvent selected from the group consisting of ester alcohol, a mixture of an ester alcohol and a glycol ether and a mixture of an ester alcohol and a glycol ether ester.
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) | 1991-08-02 | 1992-02-01 | 1992-08-02 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1995-08-02 | 1996-02-01 | 1996-08-02 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1999-08-02 | 2000-02-01 | 2000-08-02 | $7700.00 | Window Closed / Lapsed |