US3707762A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Methods of using fluxes in joining metal surfaces
Assignee: Boeing North American Inc
•
Filing: 1970-10-29
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Granted: 1973-01-02
•
Expires: 1990-10-29
Abstract
Abstract A method for joining metal surfaces such as by soft soldering, brazing or solder reflowing is provided wherein a gaseous hydrazine flux is used to remove tarnish films from the metal surfaces to permit the metal surfaces to form a good metallurgical bond.
Inventors
- 👤 J Bochinski
- 👤 K Christe
- 👤 R Wilson
- 👤 F Gunderloy
- 👤 D Pilipovich
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-01 17:52
CPC Classifications
B; B23; B23K; B23K35/00; B23K35/22; B23K35/36; B23K35/3612; B23K35/3615; B23K35/38; H; H05; H05K; H05K3/00; H05K3/30; H05K3/32; H05K3/34; H05K3/3489
Claims Analysis
Total Claims: 15
Claim 1
Independent Claim
18 words
The method of claim 1 in which R1, R2 and R3 are each hydrogen, alkyl, cycloparaffin or phenyl.
Claim 2
Dependent Claim
22 words
The method of claim 1 in which R1, R2 and R3 are each hydrogen or alkyl of one to five C atoms.
Claim 3
Dependent Claim
14 words
The method of claim 1 in which R1, R2 and R3 are each hydrogen.
Claim 4
Dependent Claim
20 words
The method of claim 1 in which the soldering is conducted at a temperature between about 350* and 525* F.
Claim 5
Dependent Claim
17 words
The method of claim 1 in which the metal surfaces are each gold, copper, nickel or silver.
Claim 6
Dependent Claim
14 words
The method of claim 1 in which the solder alloy is a soft solder.
Claim 7
Dependent Claim
16 words
The method of claim 1 in which the solder alloy is composed of tin and lead.
Claim 8
Dependent Claim
67 words
In the method of remelting a solder alloy deposit on a metal surface to reflow the solder alloy and metallurgically bond the solder alloy to the metal surface, the improvement comprising conducting said remelting and reflowing of said solder alloy in the presence of a flux which consists of gaseous hydrazine of the formula R1R2NNHR3 wherein R1, R2 and R3 are each hydrogen, aliphatic, cycloaliphatic or aromatic.
Claim 9
Dependent Claim
14 words
The method of claim 1 in which R1, R2 and R3 are each hydrogen.
Claim 10
Dependent Claim
58 words
In a method of joining metal surfaces in which a flux is employed to remove tarnish films from the metal surfaces to permit the metal surfaces to form a good metallurgical bond, the improvement in which the flux consists of gaseous hydrazine of the formula R1R2NNHR3 wherein R1, R2 and R3 are each hydrogen, aliphatic, cycloaliphatic or aromatic.
Claim 11
Dependent Claim
14 words
The method of claim 11 in which R1, R2 and R3 are each hydrogen.
Claim 12
Dependent Claim
17 words
The method of claim 11 in which the metal surfaces are joined by solid state diffusion bonding.
Claim 13
Dependent Claim
18 words
The method of claim 11 in which the gaseous hydrazine flux is in admixture with an inert gas.
Claim 14
Dependent Claim
26 words
The method of claim 14 in which the hydrazine concentration in the hydrazine flux - inert gas mixture is about 1 to 10 percent by volume.
Claim 15
Dependent Claim
12 words
The method of claim 14 in which the inert gas is nitrogen.
References Cited (Backward Citations)
CA560737A
Cited
US2612459A
Cited
US3071852A
Cited
US3174220A
Cited
US3344001A
Cited
US3357093A
Cited
US3469304A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1976-01-02 | 1976-07-03 | 1977-01-02 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1980-01-02 | 1980-07-03 | 1981-01-02 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1984-01-02 | 1984-07-03 | 1985-01-02 | $7700.00 | Window Closed / Lapsed |