Compositions – Compositions containing a single chemical reactant or plural... – Organic reactant
Patent
1995-02-13
1996-04-30
Lieberman, Paul
Compositions
Compositions containing a single chemical reactant or plural...
Organic reactant
252 792, 252 793, 252 794, 252147, 252148, 252151, 252146, 252DIG8, C23D 100
Patent
active
055122019
ABSTRACT:
A metal dissolving liquid and method for stripping tin and solder coatings, including the underlying tin-copper alloy, from the copper substrate of a printed circuit board. The liquid includes an aqueous solution of nitric acid in an amount sufficient to dissolve solder and tin, a source of ferric ions in an amount sufficient to dissolve tin-copper alloy, a source of halide ions in an amount sufficient to solubilize tin, an effective amount of methylsulfonic acid as promoter for complete stripping, and a source of an organic, water soluble amine. The combination of ingredients will substantially eliminate sludge formation, reduce attack on the copper substrate and provide a bright copper finish after solder removal. A liquid further including organic triazoles including benzotriazole in amounts not more than about 5% by weight and sulfamic ions in amounts not more than about 2.5% by weight.
REFERENCES:
patent: 2829107 (1958-04-01), Ruff et al.
patent: 2975039 (1961-03-01), Elliott
patent: 3926699 (1975-12-01), Dixon
patent: 3990982 (1976-11-01), Dixon
patent: 4410396 (1983-10-01), Somers et al.
patent: 4678541 (1987-07-01), Tytgat et al.
patent: 4713144 (1987-12-01), Schiller
patent: 4728456 (1988-03-01), Yamasoe et al.
patent: 4851148 (1989-07-01), Yamasoe et al.
patent: 4886616 (1989-12-01), Yamasoe et al.
patent: 4921571 (1990-05-01), Kukanskis et al.
patent: 4957653 (1990-09-01), Cordani
patent: 4964920 (1990-10-01), Jackson et al.
patent: 5035749 (1991-07-01), Haruta et al.
patent: 5219484 (1993-06-01), Krulik
patent: 5234542 (1993-08-01), Cordani
patent: 5244539 (1993-09-01), McGrath et al.
Krulik Gerald A.
Mandich Nenad
Singh Rajwant
Applied Chemical Technologies, Inc.
Lieberman Paul
Pratt Wyatt B.
LandOfFree
Solder and tin stripper composition does not yet have a rating. At this time, there are no reviews or comments for this patent.
If you have personal experience with Solder and tin stripper composition, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Solder and tin stripper composition will most certainly appreciate the feedback.
Profile ID: LFUS-PAI-O-625991