US4606493A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Method and apparatus for soldering plate-shaped circuit carriers inside an inert gas soldering means
Assignee: Siemens AG
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Filing: 1984-03-14
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Granted: 1986-08-19
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Expires: 2004-03-14
Abstract
Abstract The invention concerns preventing oxidation of printed circuit board metal surfaces as a result of heat produced in a solder bath arrangement and reducing thermal stress defects from occurring in the circuit carrier being soldered. An enclosed reaction chamber is provided with the solder bath and supplied with a pressurized atmosphere of inert gas which gas seals the reaction chamber from ambient air. The inert gas is discharged from jets against the solder side (the connector post side) of the printed circuit boards at a point upstream of the solder bath and the inert gas is at a temperature substantially higher than the solder bath temperature.
Inventors
- 👤 Heinz Christoph
- 👤 Jurgen Gamalski
- 👤 Eduard Lenz
- 👤 Ulrich Neumann
- 👤 Reinhard von der Schmidt
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-29 15:30
CPC Classifications
B; B23; B23K; B23K1/00; B23K1/008; B23K1/08; B23K1/085; H; H05; H05K; H05K3/00; H05K3/30; H05K3/32; H05K3/34; H05K3/3465; H05K3/3468; H05K2203/00; H05K2203/08; H05K2203/086; H05K2203/11; H05K2203/111
Claims Analysis
Total Claims: 9
Claim 1
Independent Claim
167 words
A method for inert gas soldering printed circuit boards in an enclosed reaction chamber sealed from ambient, said reaction chamber defining a longitudinal channel having opposed inlet and exit open ends, means for transporting circuit boards longitudinally from the inlet end to the outlet end from through said chamber channel, a solder bath means in said channel, and flow means for feeding inert gas under pressure into said channel, said method comprising: disposing said flow means in the form of at least one jet having an opening facing upwardly and perpendicular to the transport path of said circuit boards at a place in front of said solder bath, transporting said circuit boards over said at least one jet such that inert gas flow is directed only against the solder sides of said circuit boards, and heating said inert gas in said flow means to a temperature higher than a desired temperature for the solder side of the circuit board upon its arrival at the solder bath means.
Claim 2
Independent Claim
167 words
A method for inert gas soldering printed circuit boards in an enclosed reaction chamber sealed from ambient, said reaction chamber defining a longitudinal channel having opposed inlet and exit open ends, means for transporting circuit boards longitudinally from the inlet end to the outlet end from through said chamber channel, a solder bath means in said channel, and flow means for feeding inert gas under pressure into said channel, said method comprising: disposing said flow means in the form of at least one jet having an opening facing upwardly and perpendicular to the transport path of said circuit boards at a place in front of said solder bath, transporting said circuit boards over said at least one jet such that inert gas flow is directed only against the solder sides of said circuit boards, and heating said inert gas in said flow means to a temperature higher than a desired temperature for the solder side of the circuit board upon its arrival at the solder bath means.
Claim 3
Dependent Claim
52 words
The method of claim 1, further comprising: conducting said circuit boards over said at least one jet opening such that inert gas only briefly impinges on the solder sides of said circuit boards and heating said inert gas in said flow means to a temperature more than double the solder bath temperature.
Claim 4
Dependent Claim
35 words
The method of claim 1, further comprising: providing a lateral row of a plurality of individual said jets to form said flow means and individually controlling the flow of inert gas from each said jet.
Claim 5
Dependent Claim
173 words
Apparatus for inert gas soldering printed circuit boards in an enclosed reaction chamber sealed from ambient, said reaction chamber defining a longitudinal channel having opposed inlet and exit open ends, a solder bath means in said channel, a flow means for feeding inert gas under pressure into said channel, and means for transporting circuit boards longitudinally from the inlet end to the outlet end through said channel, the improvement comprising wherein said flow means comprises at least one jet having an opening facing upward and perpendicular to the transport path of said circuit boards at a place in front of said solder bath along the transport path, said means for transporting passing said circuit boards over said at least one jet opening such that inert gas flow is directed only against the solder sides of said circuit boards, and means for heating said inert gas in said flow means to a temperature higher than a desired temperature for the solder side of the circuit board upon its arrival at the solder bath means.
Claim 6
Dependent Claim
173 words
Apparatus for inert gas soldering printed circuit boards in an enclosed reaction chamber sealed from ambient, said reaction chamber defining a longitudinal channel having opposed inlet and exit open ends, a solder bath means in said channel, a flow means for feeding inert gas under pressure into said channel, and means for transporting circuit boards longitudinally from the inlet end to the outlet end through said channel, the improvement comprising wherein said flow means comprises at least one jet having an opening facing upward and perpendicular to the transport path of said circuit boards at a place in front of said solder bath along the transport path, said means for transporting passing said circuit boards over said at least one jet opening such that inert gas flow is directed only against the solder sides of said circuit boards, and means for heating said inert gas in said flow means to a temperature higher than a desired temperature for the solder side of the circuit board upon its arrival at the solder bath means.
Claim 7
Dependent Claim
45 words
The apparatus of claim 4, wherein said flow means comprises a lateral row of a plurality of individual said jets and the openings of said jets permit a plurality of flows of said inert gas to impinge against the solder side of each circuit board.
Claim 8
Dependent Claim
30 words
The apparatus of claim 5, wherein the flow of inert gas from each said jet is individually controllable by means of respective control valve means associated with each said jet.
Claim 9
Dependent Claim
54 words
The apparatus of claim 4, wherein said means for transporting conducts said circuit boards over said at least one jet opening such that inert gas only briefly impinges on the solder sides of said circuit boards and said heating means heats said inert gas to a temperature more than double the solder bath temperature.
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) | 1989-08-18 | 1990-02-17 | 1990-08-19 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1993-08-18 | 1994-02-17 | 1994-08-19 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1997-08-18 | 1998-02-17 | 1998-08-19 | $7700.00 | Window Closed / Lapsed |