US5340013A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Rework process for printed circuit cards and solder fountain having gas blanket for carrying out the process
Assignee: International Business Machines Corp
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Filing: 1993-12-10
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Granted: 1994-08-23
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Expires: 2013-12-10
Abstract
Abstract Disclosed is a solder tool for reworking a pin-in-hole printed circuit board. The solder tool has means for providing a gas blanket. Also disclosed is a method of reworking a pin-in-hole printed circuit board using the solder tool.
Inventors
- 👤 Joseph D. Poole
- 👤 Frank P. Zickefoose
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-31 15:43
CPC Classifications
B; B23; B23K; B23K3/00; B23K3/06; B23K3/0646; B23K3/0653; H; H05; H05K; H05K13/00; H05K13/04; H05K13/0486; H05K3/00; H05K3/30; H05K3/32; H05K3/34; H05K3/3447; H05K2203/00; H05K2203/07; H05K2203/0736; H05K2203/0746; H05K2203/08; H05K2203/086; H05K3/3465; H05K3/3468
Claims Analysis
Total Claims: 12
Claim 1
Independent Claim
160 words
A solder tool for reworking a pin-in-hole printed circuit board, said solder tool comprising: a. a solder pot for containing molten solder, said solder pot having a top surface with an opening in a top surface thereof for the upward flow of solder; b. a solder pump for pumping the molten solder upward from the solder pot through the opening in the top surface of the solder pot to the pin-in-hole printed circuit board; c. a solder nozzle extending upwardly from the solder pump through the opening in the top surface of the solder pot for carrying the molten solder into proximity with the pin-in-hole printed circuit board; and d. a circumferential conduit surrounding the solder nozzle and the opening in the top surface of the solder pot, said conduit having outlets for providing a blanket gas blanket in proximity to the solder nozzle, the opening in the top surface of the solder pot, and the pin-in-hole printed circuit board.
Claim 2
Dependent Claim
160 words
A solder tool for reworking a pin-in-hole printed circuit board, said solder tool comprising: a. a solder pot for containing molten solder, said solder pot having a top surface with an opening in a top surface thereof for the upward flow of solder; b. a solder pump for pumping the molten solder upward from the solder pot through the opening in the top surface of the solder pot to the pin-in-hole printed circuit board; c. a solder nozzle extending upwardly from the solder pump through the opening in the top surface of the solder pot for carrying the molten solder into proximity with the pin-in-hole printed circuit board; and d. a circumferential conduit surrounding the solder nozzle and the opening in the top surface of the solder pot, said conduit having outlets for providing a blanket gas blanket in proximity to the solder nozzle, the opening in the top surface of the solder pot, and the pin-in-hole printed circuit board.
Claim 3
Dependent Claim
37 words
The solder tool of claim 1 wherein the circumferential conduit surrounding the solder nozzle and the opening in the top surface of the solder pot is a sintered powder conduit having pores for discharging the blanket gas.
Claim 4
Dependent Claim
35 words
The solder tool of claim 1 wherein the circumferential conduit surrounding the solder nozzle and the opening in the top surface of the solder pot is a tube having openings for discharging the blanket gas.
Claim 5
Independent Claim
224 words
A method of reworking a pin-in-hole printed circuit board comprising the steps of: a. desoldering solder bonds connecting an integrated circuit chip to the printed circuit board; b. placing the printed circuit board in proximity to a solder tool having (a). a solder pot for containing molten solder, said solder pot having a top surface with an opening in a top surface thereof for the upward flow of solder; (b). a solder pump for pumping the molten solder upward from the solder pot through the opening in the top surface of the solder pot to the pin-in-hole printed circuit board; (c). a solder nozzle extending upwardly from the solder pump through the opening in the top surface of the solder pot for carrying the molten solder into proximity with the pin-in-hole printed circuit board; and (d). a circumferential conduit surrounding the solder nozzle and the opening in the top surface of the solder pot, said conduit having outlets for providing a blanket gas blanket in proximity to the solder nozzle, the opening in the top surface of the solder pot, and the pin-in-hole printed circuit board; c. providing a non-reactive gas blanket in proximity to the printed circuit board from the circumferential conduit; and d. providing a fountain of molten solder to the pin-in-hole printed circuit board to resolder the integrated circuit chip thereto.
Claim 6
Independent Claim
224 words
A method of reworking a pin-in-hole printed circuit board comprising the steps of: a. desoldering solder bonds connecting an integrated circuit chip to the printed circuit board; b. placing the printed circuit board in proximity to a solder tool having (a). a solder pot for containing molten solder, said solder pot having a top surface with an opening in a top surface thereof for the upward flow of solder; (b). a solder pump for pumping the molten solder upward from the solder pot through the opening in the top surface of the solder pot to the pin-in-hole printed circuit board; (c). a solder nozzle extending upwardly from the solder pump through the opening in the top surface of the solder pot for carrying the molten solder into proximity with the pin-in-hole printed circuit board; and (d). a circumferential conduit surrounding the solder nozzle and the opening in the top surface of the solder pot, said conduit having outlets for providing a blanket gas blanket in proximity to the solder nozzle, the opening in the top surface of the solder pot, and the pin-in-hole printed circuit board; c. providing a non-reactive gas blanket in proximity to the printed circuit board from the circumferential conduit; and d. providing a fountain of molten solder to the pin-in-hole printed circuit board to resolder the integrated circuit chip thereto.
Claim 7
Dependent Claim
21 words
The method of claim 4 comprising providing a no-clean flux on surfaces of the pin-in-hole printed circuit board to be resoldered.
Claim 8
Dependent Claim
22 words
The method of claim 5 wherein the no-clean flux comprises a substantially non-corrosive, substantially electrically non-conducting organic acid in an alcohol solvent.
Claim 9
Dependent Claim
31 words
The method of claim 6 wherein the no-clean flux is chosen from the group consisting of: a. abietic acid and an activator in alcohol; and b. adipic acid in an alcohol.
Claim 10
Dependent Claim
30 words
The method of claim 5 wherein the gas blanket consists essentially of a gas chosen from the group consisting of helium, argon, nitrogen, carbon dioxide, water, hydrogen, and mixtures thereof.
Claim 11
Dependent Claim
11 words
The method of claim 5 wherein the gas blanket comprises nitrogen.
Claim 12
Dependent Claim
22 words
The method of claim 8 wherein the gas blanket consists essential of nitrogen with less then 5 volume percent oxygen contained therein.
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) | 1997-08-22 | 1998-02-21 | 1998-08-23 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 2001-08-22 | 2002-02-21 | 2002-08-23 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2005-08-22 | 2006-02-21 | 2006-08-23 | $7700.00 | Window Closed / Lapsed |