US3717482A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Stabilized electroless plating solutions
Assignee: Shipley Co Inc
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Filing: 1971-11-16
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Granted: 1973-02-20
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Expires: 1991-11-16
Abstract
Abstract An electroless nickel or cobalt plating solution is characterized by the addition of a small but effective amount of a source of mercury ions for increased bath stability. It is known in the art that solutions for electroless plating are unstable and tend to decompose with use. It is also known that decomposition can be retarded and the useful life of a plating solution increased by the addition of various additives, frequently catalytic poisons, in very small concentrations. In accordance with the present invention, it has been found that the stability of an electroless nickel or cobalt plating solution can be substantially increased by the addition of a source of mercury ions alone as a primary stabilizer, or preferably, by the addition of the mercury ions as a secondary stabilizer in combination with a prior art stabilizer as primary stabilizer. The combination of stabilizers provides a synergism with stability substantially improved over that obtainable with either component of the combination alone. One characteristic of the present invention is the co-deposition of mercury in minute amounts with the plating metal.
Inventors
- 👤 M Gulla
- 👤 O Dutkewych
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-05 18:18
CPC Classifications
C; C23; C23C; C23C18/00; C23C18/16; C23C18/31; C23C18/32; C23C18/34; C23C18/36; C23C18/48; C23C18/50; Y; Y10; Y10T; Y10T428/00; Y10T428/31504; Y10T428/31678
Claims Analysis
Total Claims: 18
Claim 1
Independent Claim
49 words
In an aqueous electroless metal plating solution of nickel, cobalt or mixtures thereof including a source of the metal ions and hypophosphite as a reducing agent therefor and a complexing agent, the improvement comprising mercury ions in solution in a small but effective amount to provide increased bath stability.
Claim 2
Dependent Claim
49 words
In an aqueous electroless metal plating solution of nickel, cobalt or mixtures thereof including a source of the metal ions and hypophosphite as a reducing agent therefor and a complexing agent, the improvement comprising mercury ions in solution in a small but effective amount to provide increased bath stability.
Claim 3
Dependent Claim
15 words
The composition of claim 1 where the mercury ions are derived from a mercury salt.
Claim 4
Dependent Claim
21 words
The composition of claim 1 where the mercury ions are in solution in an amount varying from a trace to saturation.
Claim 5
Dependent Claim
26 words
The composition of claim 1 where the mercury ions are in solution in an amount varying from 1 to 100 parts per million parts of solution.
Claim 6
Dependent Claim
17 words
The composition of claim 1 in combination with a second stabilizing agent for the electroless metal solution.
Claim 7
Dependent Claim
35 words
The composition of claim 5 where the second stabilizing agent is selected from the group consisting of a divalent sulphur compound, a cyanide compound including nitriles and dinitriles, lead ions, iodate compounds and acetylinic compounds.
Claim 8
Dependent Claim
49 words
The composition of claim 6 where the acetylinic compounds corresponds to one of the following general formulas: R - C * CH or R'' - C * C - R'''' where each of R,R'', and R'''' are radicals selected from the class of monovalent hydroxyalkyl, cyclohydroxyalkyl, and hydroxyalkyl ether.
Claim 9
Dependent Claim
37 words
The composItion of claim 1 comprising a source of nickel ions, hypophosphite as a reducing agent therefore, a pH adjuster and mercury ions in solution in a small but effective amount capable of providing increased bath stability.
Claim 10
Dependent Claim
15 words
The composition of claim 8 in combination with a second stabilizer for electroless nickel solution.
Claim 11
Dependent Claim
26 words
The composition of claim 9 where the second stabilizer is selected from the group consisting of divalent sulphur compounds, lead ion, iodate compounds, and acetylinic compounds.
Claim 12
Dependent Claim
47 words
The composition of claim 10 where the acetylinic compound corresponds to one of the following formulas: R - C * CH or R'' - C * C - R'''' where R, R'' and R'''' are radicals selected from the group of monovalent hydroxyalkyl, cyclohydroxyalkyl, and hydroxyalkyl ether.
Claim 13
Dependent Claim
12 words
The composition of claim 10 where the second stabilizer is lead ions.
Claim 14
Dependent Claim
14 words
The composition of claim 10 where the second stabilizer is a divalent sulfur compound.
Claim 15
Dependent Claim
13 words
The composition of claim 10 where the second stabilizer is an iodate compound.
Claim 16
Independent Claim
57 words
A method for increasing the stability of an electroless nickel, cobalt or nickel-cobalt alloy-hypophosphite plating solution and retarding the time in which the electroless plating solution spontaneously decomposes comprising the step of adding a mercury compound to said electroless plating solution in a concentration capable of providing a small but effective amount of mercury ions in solution.
Claim 17
Independent Claim
57 words
A method for increasing the stability of an electroless nickel, cobalt or nickel-cobalt alloy-hypophosphite plating solution and retarding the time in which the electroless plating solution spontaneously decomposes comprising the step of adding a mercury compound to said electroless plating solution in a concentration capable of providing a small but effective amount of mercury ions in solution.
Claim 18
Dependent Claim
26 words
An article of manufacture comprising a substrate coated with electroless metal-phosphorus alloy deposited from the solution of claim 1 and characterized by the co-deposition of mercury.
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) | 1976-02-20 | 1976-08-21 | 1977-02-20 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1980-02-20 | 1980-08-21 | 1981-02-20 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1984-02-20 | 1984-08-21 | 1985-02-20 | $7700.00 | Window Closed / Lapsed |