Patent US4595605A successfully refreshed from Google Patents.
US4595605A
Expired / Lapsed
US
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Solderable conductive compositions that are capable of being soldered by non silver-bearing solder and that can be bonded directly to substrates and which are flexible
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 vinyl chloride/vinyl acetate copolymer. 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 good conductivity, solderability and flexibility characteristics. Additionally, these compositions are capable of being soldered by non silver-bearing solder.
Inventors
- 👤 Frank W. Martin
- 👤 Samson Shahbazi
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-29 14:59
CPC Classifications
C; C04; C04B; C04B41/00; C04B41/009; C04B41/45; C04B41/50; C04B41/51; C04B41/5116; C04B41/80; C04B41/81; C04B41/85; C04B41/88; H; H01; H01B; H01B1/00; H01B1/20; H01B1/22; H05; H05K; H05K1/00; H05K1/02; H05K1/09; H05K1/092; H05K1/095; C04B2111/00; C04B2111/00474; C04B2111/00844; Y; Y10; Y10S; Y10S428/00; Y10S428/901
Claims Analysis
Total Claims: 12
Claim 1
Independent Claim
74 words
A directly solderable conductive composition comprising after cure: (a) from about 88 to about 93% by weight silver, said silver beiing 100% in the form of flake having an average particle size of about 0.5 to about 50 microns; and (b) from about 7 to about 12% by weight vinyl chloride/-vinyl acetate copolymer, said copolymer having a number average molecular weight from about 14,000 to about 35, 000 and containing no carboxylic acid groups.
Claim 2
Dependent Claim
74 words
A directly solderable conductive composition comprising after cure: (a) from about 88 to about 93% by weight silver, said silver beiing 100% in the form of flake having an average particle size of about 0.5 to about 50 microns; and (b) from about 7 to about 12% by weight vinyl chloride/-vinyl acetate copolymer, said copolymer having a number average molecular weight from about 14,000 to about 35, 000 and containing no carboxylic acid groups.
Claim 3
Dependent Claim
22 words
The composition of claim 1 wherein the weight ratio of vinyl chloride to vinyl acetate is from about 80:20 to about 90:10.
Claim 4
Independent Claim
96 words
A method of making a conductive composition that is directly solderable and flexible comprising dissolving from about 5% to about 9% by weight vinyl chloride/-vinyl acetate copolymer in about 20% to about 25% by weight ketone solvent and mixing the resultant solution with about 68% to about 75% by weight silver; said vinyl chloride/vinyl acetate copolymer having a number average molecular weight from about 14,000 to about 35,000 and containing no carboxylic acid groups, and said silver being 100% in the form of flake having an average particle size of about 0.5 to about 50 microns.
Claim 5
Independent Claim
96 words
A method of making a conductive composition that is directly solderable and flexible comprising dissolving from about 5% to about 9% by weight vinyl chloride/-vinyl acetate copolymer in about 20% to about 25% by weight ketone solvent and mixing the resultant solution with about 68% to about 75% by weight silver; said vinyl chloride/vinyl acetate copolymer having a number average molecular weight from about 14,000 to about 35,000 and containing no carboxylic acid groups, and said silver being 100% in the form of flake having an average particle size of about 0.5 to about 50 microns.
Claim 6
Dependent Claim
28 words
The method of claim 3 additionally comprising applying the vinyl chloride/vinyl acetate copolymer, ketone solvent, silver flake mixture to a substrate and then drying and curing the mixture.
Claim 7
Dependent Claim
16 words
The method of claim 4 wherein the mixture is applied at a thickness of one mil.
Claim 8
Dependent Claim
16 words
The method of claim 4 wherein the mixture is applied to the substrate by silk screening.
Claim 9
Dependent Claim
20 words
The method of claim 3 wherein the ketone solvent selected from the group consisting of gamma butyrolactone, acetone, and cyclohexane.
Claim 10
Dependent Claim
10 words
The method of claim 4 wherein the substrate is flexible.
Claim 11
Dependent Claim
13 words
The method of claim 4 wherein the substrate is a printed circuit board.
Claim 12
Dependent Claim
31 words
The method of claim 4 wherein the mixture is dried and cured at a temperature of from about 100° C. to about 170° C. for about 15 to about 60 minutes.
References Cited (Backward Citations)
US4371459A
Cited
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 |