US5324400A
Expired / Lapsed
US
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Electrode preconditioning method for a plating bath monitoring process
Assignee: Technic Inc
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Filing: 1992-12-04
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Granted: 1994-06-28
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Expires: 2012-12-04
Abstract
Abstract A method of preconditioning an electrode for use in a plating bath monitoring process. The method involves applying at least one anodic signal to an electrode in contact with the plating bath solution in order to yield a reproducibly clean and stabilized electrode surface, and then applying a plating signal to deposit a layer of metal on the anodically treated electrode. The resultant preconditioned electrode improves the accuracy and precision of subsequent voltammetric monitoring measurements for a variety of different plating baths. The method is easily integrated with and thereby enhances the capabilities of known voltammetric plating bath monitoring processes.
Inventors
- 👤 Bruce M. Eliash
- 👤 Nguyet H. Phan
- 👤 Frank A. Ludwig
- 👤 Vilambi N. Reddy
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-08 04:58
CPC Classifications
G; G01; G01N; G01N27/00; G01N27/26; G01N27/28; G01N27/30; G01N27/38
Claims Analysis
Total Claims: 14
Claim 1
Independent Claim
129 words
A method of preconditioning a working electrode used for monitoring constituents in a plating bath solution, said method comprising the steps of: applying at least one anodic signal to said working electrode positioned within said solution, said anodic signal having a potential and applied for a period of time such that a reproducibly clean and stabilized surface is formed on said working electrode, producing an anodically treated working electrode; and applying a plating signal to said anodically treated working electrode to deposit a layer of metal onto said anodically treated working electrode; repeating said steps of applying anodic and plating signals to produce a preconditioned working electrode; wherein voltammetric measurement signals can then be applied to said preconditioned working electrode to accurately monitor particular constituents within said plating bath.
Claim 2
Independent Claim
129 words
A method of preconditioning a working electrode used for monitoring constituents in a plating bath solution, said method comprising the steps of: applying at least one anodic signal to said working electrode positioned within said solution, said anodic signal having a potential and applied for a period of time such that a reproducibly clean and stabilized surface is formed on said working electrode, producing an anodically treated working electrode; and applying a plating signal to said anodically treated working electrode to deposit a layer of metal onto said anodically treated working electrode; repeating said steps of applying anodic and plating signals to produce a preconditioned working electrode; wherein voltammetric measurement signals can then be applied to said preconditioned working electrode to accurately monitor particular constituents within said plating bath.
Claim 3
Dependent Claim
22 words
The method of claim 1 wherein said plating signal is a pulsed dc, periodic reversed dc or ac superimposed on dc signal.
Claim 4
Dependent Claim
27 words
The method of claim 1 wherein said anodic signal has a potential of about 2 to 3.5 volts and is applied for about 5 to 40 seconds.
Claim 5
Dependent Claim
23 words
The method of claim 1 wherein said working electrode is formed from a material selected from the group consisting of platinum and gold.
Claim 6
Dependent Claim
40 words
The method of claim 1 wherein said layer of metal deposited on said working electrode is selected from the group consisting of copper, iron, nickel, chromium, zinc, tin, gold, silver, lead, platinum, cadmium, palladium, rhodium, indium, cobalt and mixtures thereof.
Claim 7
Dependent Claim
36 words
The method of claim 1 wherein said plating signal is a constant dc signal, either potentiostatic or galvanostatic, having a cathodic amplitude sufficient to plate the metal and a duration of about 10 to 60 seconds.
Claim 8
Dependent Claim
23 words
The method of claim 1 wherein said plating bath is a chromium plating bath and further wherein said chromium bath contains several constituents.
Claim 9
Dependent Claim
40 words
The method of claim 7 wherein one of said constituents in said chromium plating bath is chromic acid and further wherein said anodic signal has a potential of about 2.4 volts and is applied for about 20 to 36 seconds.
Claim 10
Dependent Claim
40 words
The method of claim 7 wherein one of said constituents in said chromium plating bath is silicofluoride catalyst and further wherein said anodic signal has a potential of about 2.4 volts and is applied for about 20 to 36 seconds.
Claim 11
Dependent Claim
38 words
The method of claim 7 wherein one of said constituents in said chromium plating bath is sulfate catalyst and further wherein said anodic signal has a potential of about 2.4 volts and is applied for about 20 seconds.
Claim 12
Dependent Claim
31 words
The method of claim 8 wherein said plating signal is a dc signal having an amplitude of about -1.1 to -1.5 volts and a duration of about 40 to 60 seconds.
Claim 13
Dependent Claim
31 words
The method of claim 9 wherein said plating signal is a dc signal having an amplitude of about -1.1 to -1.5 volts and a duration of about 20 to 36 seconds.
Claim 14
Dependent Claim
27 words
The method of claim 10 wherein said plating signal is a dc signal having an amplitude of about -1.1 volts and a duration of about 40 seconds.
References Cited (Backward Citations)
No citation records indexed.
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| 3.5 Years (Year 4) | 1997-06-27 | 1997-12-27 | 1998-06-28 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 2001-06-27 | 2001-12-27 | 2002-06-28 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2005-06-27 | 2005-12-27 | 2006-06-28 | $7700.00 | Window Closed / Lapsed |