US4595604A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Conductive compositions that are directly solderable and flexible and that can be bonded directly to substrates
Assignee: National Starch and Chemical Investment Holding Corp
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Filing: 1984-07-18
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Granted: 1986-06-17
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Expires: 2004-07-18
Abstract
Abstract This invention provides conductive compositions that are solderable and flexible and that can be bonded directly to substrates. These compositions are made up of a combination of silver exclusively in the form of flake and resin system, said resin system comprising of vinyl chloride/vinyl acetate copolymer, epoxy resin and epoxy hardner. Also provided is a method of making these compositions. Another embodiment of this invention is a method of applying conductive compositions directly to substrates by bonding the conductive compositions directly to the substrate. Once cured, the compositions demonstrate good adhesion directly to the substrate in addition to excellent conductivity, solderability and flexibility characteristics.
Inventors
- 👤 Frank W. Martin
- 👤 Samson Shahbazi
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-25 18:50
CPC Classifications
H; H05; H05K; H05K1/00; H05K1/02; H05K1/09; H05K1/092; H05K1/095; C; C08; C08K; C08K3/00; C08K3/02; C08K3/08; H01; H01B; H01B1/00; H01B1/20; H01B1/22; Y; Y10; Y10S; Y10S428/00; Y10S428/901
Claims Analysis
Total Claims: 17
Claim 1
Independent Claim
116 words
A directly solderable and flexible conductive composition comprising from about 88% to about 95% by weight silver and a resin system comprising, based on total weight of said composition: (a) from about 4% to about 7% by weight vinyl chloride/vinyl acetate copolymer; (b) from about 0.25% to about 2% by weight epoxy resin; and (c) from about 0.5% to about 3% by weight epoxy hardener; said silver being 100% in the form of flake having an average particle size from about 0.5 to about 50 microns, said vinyl chloride/vinyl acetate copolymer having a number average molecular weight from about 14,000 to 35,000 and containing no carboxylic acid groups, and said epoxy being non-aqueous-based and heat curable.
Claim 2
Dependent Claim
116 words
A directly solderable and flexible conductive composition comprising from about 88% to about 95% by weight silver and a resin system comprising, based on total weight of said composition: (a) from about 4% to about 7% by weight vinyl chloride/vinyl acetate copolymer; (b) from about 0.25% to about 2% by weight epoxy resin; and (c) from about 0.5% to about 3% by weight epoxy hardener; said silver being 100% in the form of flake having an average particle size from about 0.5 to about 50 microns, said vinyl chloride/vinyl acetate copolymer having a number average molecular weight from about 14,000 to 35,000 and containing no carboxylic acid groups, and said epoxy being non-aqueous-based and heat curable.
Claim 3
Dependent Claim
21 words
The composition of claim 1 wherein the ratio of vinyl chloride to vinyl acetate is from about 80:20 to about 90:10.
Claim 4
Dependent Claim
56 words
A method of making a conductive composition of claim 1 comprising dissolving said vinyl chloride/vinyl acetate copolymer in ketone solvent to form a first solution, dissolving said epoxy resin and epoxy hardener in ester solvent to form a second solution and then mixing the first and second solutions with said silver flake to form a mixture.
Claim 5
Dependent Claim
27 words
The method of claim 3 wherein the weight ratio of silver flake to vinyl chloride/vinyl acetate copolymer to epoxy resin is from about 68:4:4 to about 75:6:2.
Claim 6
Dependent Claim
22 words
The method of claim 3 wherein the weight ratio of epoxy resin to epoxy hardner is from about 40:60 to about 36:63.
Claim 7
Dependent Claim
24 words
The method of claim 3 wherein the weight ratio of vinyl chloride/vinyl acetate copolymer to ketone solvent is from about 15:85 to about 25:75.
Claim 8
Dependent Claim
25 words
The method of claim 3 wherein the weight ratio of epoxy resin and epoxy hardner to ester solvent is from about 100:1 to about 75:25.
Claim 9
Dependent Claim
24 words
The method of claim 3 wherein the weight ratio of the first solution to the second solution is from about 100:1 to about 88:12.
Claim 10
Dependent Claim
75 words
The method of claim 3 wherein the vinyl chloride/vinyl acetate copolymer is present in an amount of from about 15% to about 25%, of the first solution, by weight, the epoxy resin and epoxy hardener is present in an amount of from about 70% to about 99% of the second solution, by weight, and the silver flake is present in an amount of from about 68% to about 75% of the total mixture, by weight.
Claim 11
Dependent Claim
19 words
The method of claim 3 additionally comprising applying the mixture to a substrate, then drying and curing the mixture.
Claim 12
Dependent Claim
13 words
The method of claim 10 wherein the mixture is applied by silk screening.
Claim 13
Dependent Claim
10 words
The method of claim 10 wherein the substrate is flexible.
Claim 14
Dependent Claim
30 words
The method of claim 10 wherein the mixture is dried and cured at a temperature of from abut 100° C. to about 170° C. from about 15 to 60 minutes.
Claim 15
Dependent Claim
22 words
A method of applying a conductive composition onto a substrate comprising bonding the conductive composition of claim 1 directly to the substrate.
Claim 16
Dependent Claim
23 words
The method of claim 14 wherein the force required to remove the conductive composition from a rigid substrate is greater than 500 p.s.i.
Claim 17
Dependent Claim
10 words
The method of claim 14 wherein the substrate is flexible.
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) | 1989-06-16 | 1989-12-16 | 1990-06-17 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1993-06-16 | 1993-12-16 | 1994-06-17 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1997-06-16 | 1997-12-16 | 1998-06-17 | $7700.00 | Window Closed / Lapsed |