US4604144A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Process for cleaning a circuit board
Assignee: AT&T Inc
•
Filing: 1985-09-11
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Granted: 1986-08-05
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Expires: 2005-09-11
Abstract
Abstract In a method of cleaning a circuit board having a silicone encapsulated hybrid integrated circuit thereon, subsequent to aqueous solder flux residue removal with an ionic detergent, the board is cleaned with a low molecular weight organic acid such as formic, acetic or oxalic acid.
Inventors
- 👤 Ching-Ping Wong
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-01 07:04
CPC Classifications
H; H05; H05K; H05K3/00; H05K3/22; H05K3/26; C; C23; C23G; C23G1/00; C23G1/02; C23G1/10; C23G1/103; H05K2203/00; H05K2203/07; H05K2203/0779; H05K2203/0786; H05K2203/0789; H05K2203/12; H05K2203/122; H05K3/28; H05K3/284
Claims Analysis
Total Claims: 12
Claim 1
Independent Claim
57 words
A method of cleaning a circuit board subsequent to soldering with a water soluble flux which comprises: (1) washing the board in an aqueous detergent solution, (2) rinsing the board with water, (3) washing the board in an aqueous solution of a low molecular weight mono or dicarboxylic acid, and then (4) rinsing the board with water.
Claim 2
Independent Claim
57 words
A method of cleaning a circuit board subsequent to soldering with a water soluble flux which comprises: (1) washing the board in an aqueous detergent solution, (2) rinsing the board with water, (3) washing the board in an aqueous solution of a low molecular weight mono or dicarboxylic acid, and then (4) rinsing the board with water.
Claim 3
Dependent Claim
15 words
The method recited in claim 1, wherein the detergent solution comprises an ionic type detergent.
Claim 4
Dependent Claim
11 words
The method recited in claim 2, wherein the detergent comprises ethanolamine.
Claim 5
Dependent Claim
27 words
The method recited in claim 3, wherein the aqueous acid solution comprises at least one acid selected from the group consisting of formic, acetic and oxalic acids.
Claim 6
Dependent Claim
27 words
The method recited in claim 1, wherein the aqueous acid solution comprises at least one acid selected from the group consisting of formic, acetic and oxalic acid.
Claim 7
Dependent Claim
19 words
The method recited in claim 5, wherein the aqueous acid solution contains from 2.5 to 10 weight percent acid.
Claim 8
Independent Claim
78 words
A method of cleaning a circuit board subsequent to soldering a silicone encapulated hybrid integrated circuit thereon with a water soluble solder flux which comprises: (1) treating the board with an aqueous ionic detergent solution; (2) rinsing the board with water; (3) treating the board with an aqueous solution of a low molecular weight organic acid comprising an acid selected from the group consisting of monocarboxylic acids and dicarboxylic acids; and then (4) rinsing the board with water.
Claim 9
Independent Claim
78 words
A method of cleaning a circuit board subsequent to soldering a silicone encapulated hybrid integrated circuit thereon with a water soluble solder flux which comprises: (1) treating the board with an aqueous ionic detergent solution; (2) rinsing the board with water; (3) treating the board with an aqueous solution of a low molecular weight organic acid comprising an acid selected from the group consisting of monocarboxylic acids and dicarboxylic acids; and then (4) rinsing the board with water.
Claim 10
Dependent Claim
23 words
The method recited in claim 7, wherein the silicone is caused to swell prior to or during treatment with said aqueous acid solution.
Claim 11
Dependent Claim
35 words
The method recited in claim 8, wherein the board is caused to swell by means of exposing said board to an aqueous swellant solution comprising a member of the group consisting of alcohol and fluorochlorocarbons.
Claim 12
Dependent Claim
21 words
The method recited in claim 9 wherein said alcohol is selected from the group consisting of methanol, ethanol, propanol and isopropanol.
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USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1989-08-04 | 1990-02-03 | 1990-08-05 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1993-08-04 | 1994-02-03 | 1994-08-05 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1997-08-04 | 1998-02-03 | 1998-08-05 | $7700.00 | Window Closed / Lapsed |