US4360392A
Expired / Lapsed
US
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Solder flux composition
Assignee: STC PLC
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Filing: 1981-01-23
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Granted: 1982-11-23
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Expires: 2001-01-23
Abstract
Abstract A solder flux composition comprises a mixture of sarcosine and tartronic or tartaric acid dissolved in water and an aliphatic alcohol. Typically the acid-sarcosine weight ratio lies within the range 90:10 to 30:70 and the solution may contain between 5 and 20 weight percent of solids. The flux is employed for tin/lead soldering of a range of metals and alloys including copper, nickel and nickel-iron. Bidegradation of the flux is inhibited by the inclusion of lead carbonate, phenol or salicylic acid in the composition.
Inventors
- 👤 Daniel F. T. Roberts
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-03 19:56
CPC Classifications
B; B23; B23K; B23K35/00; B23K35/22; B23K35/36; B23K35/3612; B23K35/3618
Claims Analysis
Total Claims: 15
Claim 1
Independent Claim
82 words
A solder flux composition, including an amount of tartronic acid or tartaric acid and an amount of sarcosine dissolved in a solvent comprising water or a miscible mixture of water and one or more aliphatic alcohols, wherein the weight ratio of said amount of acid to said amount of sarcosine is from 90:10 to 30:70 and said amount of sarcosine is sufficient to suppress the de-wetting effects of the decomposition products of said acid produced by heating said flux to soldering temperatures.
Claim 2
Dependent Claim
82 words
A solder flux composition, including an amount of tartronic acid or tartaric acid and an amount of sarcosine dissolved in a solvent comprising water or a miscible mixture of water and one or more aliphatic alcohols, wherein the weight ratio of said amount of acid to said amount of sarcosine is from 90:10 to 30:70 and said amount of sarcosine is sufficient to suppress the de-wetting effects of the decomposition products of said acid produced by heating said flux to soldering temperatures.
Claim 3
Dependent Claim
27 words
A solder flux composition as claimed in claim 1 further including a biologically effective proportion of an antibiodegradation agent comprising phenol or salicylic acid or mixtures thereof.
Claim 4
Dependent Claim
29 words
A solder flux composition as claimed in claim 2, wherein the antibiodegradation agent comprises 0.002 to 0.005 weight percent, based on the weight of the flux, of lead carbonate.
Claim 5
Dependent Claim
27 words
A solder flux composition as claimed in claim 2, wherein the antibiodegradation agent comprises 0.001 to 1.0 weight percent of phenol or salicylic acid or mixtures thereof.
Claim 6
Dependent Claim
23 words
A flux composition as claimed in claim 1 and wherein the solvent comprises a mixture of equal volumes of water and isopropyl alcohol.
Claim 7
Dependent Claim
26 words
The solder flux composition as claimed in claim 1 wherein the acid is tartronic acid and the solvent is a 40:60 volume mixture of isopropyl alcohol:water.
Claim 8
Dependent Claim
31 words
The solder flux composition as claimed in claim 1 wherein the acid is tartaric acid and the solvent is a mixture of isopropyl alcohol:water in a ratio by volume under 30:70.
Claim 9
Dependent Claim
23 words
A flux composition as claimed in claim 1 and in which the solution concentration is between 5 and 20 weight percent of solids.
Claim 10
Dependent Claim
31 words
A flux composition as claimed in any one of claims 1, 2, 3, 4, 5, 6, 7 or 8 and wherein the weight concentrations of sarcosine and acid are substantially equal.
Claim 11
Dependent Claim
23 words
A flux composition as claimed in claim 9 and in which the solution concentration is between 10 and 20 weight percent of solids.
Claim 12
Dependent Claim
20 words
A flux composition as claimed in claim 9 and in which the solution concentration is 5 weight percent of solids.
Claim 13
Dependent Claim
20 words
A flux composition as claimed in claim 10 and in which the solution concentration is 15 weight percent of solids.
Claim 14
Dependent Claim
21 words
A flux composition as claimed in claim 9 and which includes from 0.005 to 0.1 weight percent of a wetting agent.
Claim 15
Dependent Claim
22 words
A flux composition as claimed in claim 13 and in which the weight percent of wetting agent is between 0.005 and 0.02.
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) | 1985-11-22 | 1986-05-24 | 1986-11-23 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1989-11-22 | 1990-05-24 | 1990-11-23 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1993-11-22 | 1994-05-24 | 1994-11-23 | $7700.00 | Window Closed / Lapsed |