US3754940A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Electroless plating solutions containing sulfamic acid and salts thereof
Assignee: Crown City Plating Co
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Filing: 1972-09-06
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Granted: 1973-08-28
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Expires: 1992-09-06
Abstract
Abstract Sulfamic acid and its salts are used to stabilize alkaline electroless copper plating solutions against decomposition. When employed in the second bath of a two-bath electroless plating system, the presence of sulfamic acid and its salts permits rapid deposition, over a broad range of concentrations, of copper onto an initial copper or nickel plate, while preventing deposition of copper onto a noble metal catalyzed surface. The stabilizers also serve to supplement single-bath electroless copper plating systems.
Inventors
- 👤 L Kadison
- 👤 E Maguire
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-05 13:30
CPC Classifications
C; C23; C23C; C23C18/00; C23C18/16; C23C18/31; C23C18/38; C23C18/40
Claims Analysis
Total Claims: 4
Claim 1
Independent Claim
134 words
In an aqueous alkaline electroless copper plating solution comprising at least one water soluble cupric salt, at least one complexing agent for cupric ions, at least one reducing agent for cupric ions and a pH adjustor to maintain the solution at a pH of about 11 to 14, the improvement comprising a sulfamic acid compound selected from the group consisting of sulfamic acid, salts of sulfamic acid and mixtures thereof said sulfamic acid compound being present in an amount from about 0.02 to about 4.5 moles per liter of solution and sufficient to prevent deposition of copper on an article having a catalytic noble metal surface but in sufficient to prevent deposition of copper onto an article having a thin coating of a deposited metal receptive to the deposition of copper from said solution.
Claim 2
Dependent Claim
31 words
An aqueous alkaline electroless copper plating solution as claimed in claim 2 in which the sulfamic acid compound concentration is from about 0.3 to about 4.5 mols per liter of solution.
Claim 3
Dependent Claim
138 words
An aqueous alkaline electroless copper plating solution which will prevent copper deposition onto a noble metal catalyzed surface but will not prevent copper deposition onto a metal plate receptive to the deposition of copper from said solution, the solution comprising from about 0.2 to about 0.15 mols per liter of a water soluble ionic cupric salt; from a 0.03 to about 0.75 mols per liter of a complexing agent for cupric ions; from about 0.025 to 0.5 mols per liter of a reducing agent for cupric ions; an amount of an alkali metal hydroxide to maintain the solution at a pH of from about 11 to about 14.0 and from about 0.02 to about 4.5 mols per liter of a sulfamic acid compound selected from the group consisting of sulfamic acid, salts of sulfamic acid and mixtures thereof.
Claim 4
Dependent Claim
30 words
An aqueous alkaline electroless plating solution as claimed in claim 4 in which the sulfamic acid compound concentration is from about 0.3 to about 4.5 mols per liter of solution.
References Cited (Backward Citations)
No citation records indexed.
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1976-08-27 | 1977-02-26 | 1977-08-28 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1980-08-27 | 1981-02-26 | 1981-08-28 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1984-08-27 | 1985-02-26 | 1985-08-28 | $7700.00 | Window Closed / Lapsed |