US3716464A
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US
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Method for electrodepositing of alloy film of a given composition from a given solution
Assignee: International Business Machines Corp
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Filing: 1969-12-30
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Granted: 1973-02-13
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Expires: 1989-12-30
Abstract
Abstract The effect of superimposing a sinusoidal alternating current on a direct current during electrodeposition of Ni-Fe alloys is disclosed in terms of the following factors: (a) maintaining the pH at the electrode equal to that of the bulk electrolyte; (b) ionic diffusion processes; and (c) chemical processes in solution prior to electrochemical reduction. The effect of frequency, amplitude and the rate of a-c current to d-c current on the composition of electrodeposited alloy are given for acid solutions of different pH and for alkaline solutions of metallic complexes with a variable concentration of complexing agent. It is shown that by proper choice of conditions, electrodeposited Fe-Ni alloys can be prepared with a desired uniform composition throughout their thickness. In the practice of this disclosure, alternating current is superimposed on direct current to prevent the pH in the layer of solution adjacent to the electrode from increasing and thus influence the electrodeposition of iron group metals or alloys of any metals which readily form hydroxide. Formation of hydroxides is thus prevented and their inclusion into deposited film is precluded. Additionally, the a-c current beneficially affects the rate of deposition of a metal which is controlled by diffusion. There is no concentration gradient of composition across the thickness of a film of Ni-Fe deposited by practice of this disclosure. Illustratively, Ni and Fe plate out at the same rate for thickness of film approximately in the range of 300A. to 4,000A. By control of the density of the d-c current, and the amplitude and frequency of the a-c current, Ni-Fe film of any given composition approximately in the range of 6 to 60 percent Fe is electroplated from the same solution.
Inventors
- 👤 Z Kovac
- 👤 J Olsen
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-03 00:58
CPC Classifications
C; C25; C25D; C25D3/00; C25D3/02; C25D3/56; C25D3/562; C25D15/00; C25D15/02; C25D21/00; C25D21/12; C25D5/00; C25D5/18; Y; Y10; Y10S; Y10S204/00; Y10S204/09
Claims Analysis
Total Claims: 8
Claim 1
Independent Claim
370 words
Method of electrodepositing a Fe-Ni alloy film with a given composition from an electroplating solution having a given PH, a first concentration of a given metal Fe and a second concentration of a given alloying agent Ni comprising the steps of: establishing an electroplating solution wherein the concentration of a given metal Fe therein is a first given molar and the concentration of a given alloying agent Ni therein is a second given molar and the concentration of said metal and said alloying agent is a third given molar, and the pH of said solution is a given value, said first, second and third given molars and said pH being in a given relationship to said concentrations of said metal and said alloying agent in said solution; said solution is acid, said solution includes a tartrate as a complexing agent for said metal, said first given molar concentration of said Fe is approximately in the range of 10 3 to 10 2, said second given molar concentration of said Ni is approximately in the range of 10 2 to 10 1 and said third molar concentration of said Fe and said Ni is approximately in the range of 10 1 to 10 2; applying a direct current to said electroplating solution having a given cathodic value; applying an alternating current to said electroplating solution; establishing the peak value of said alternating current in a given relationship to said given cathodic value of said direct current such that the oxidation of cathodically adsorbed hydrogen is the main anodic reaction of said electroplating solution; said electroplating solution having an electrodeposition characteristic of percentage of said alloying agent deposited cathodically from said solution versus frequency of said applied alternating current exhibiting a given slope in a first portion over a given low range of frequencies, a slope greater than said given slope in a second portion over a middle range of higher frequencies, and a slope less than said greater slope in a third portion over a still higher range of frequencies; an depositing a given composition of said electrodeposited film by establishing the frequency of said applied alternating current at a value in said middle range of higher frequencies of said characteristic.
Claim 2
Dependent Claim
370 words
Method of electrodepositing a Fe-Ni alloy film with a given composition from an electroplating solution having a given PH, a first concentration of a given metal Fe and a second concentration of a given alloying agent Ni comprising the steps of: establishing an electroplating solution wherein the concentration of a given metal Fe therein is a first given molar and the concentration of a given alloying agent Ni therein is a second given molar and the concentration of said metal and said alloying agent is a third given molar, and the pH of said solution is a given value, said first, second and third given molars and said pH being in a given relationship to said concentrations of said metal and said alloying agent in said solution; said solution is acid, said solution includes a tartrate as a complexing agent for said metal, said first given molar concentration of said Fe is approximately in the range of 10 3 to 10 2, said second given molar concentration of said Ni is approximately in the range of 10 2 to 10 1 and said third molar concentration of said Fe and said Ni is approximately in the range of 10 1 to 10 2; applying a direct current to said electroplating solution having a given cathodic value; applying an alternating current to said electroplating solution; establishing the peak value of said alternating current in a given relationship to said given cathodic value of said direct current such that the oxidation of cathodically adsorbed hydrogen is the main anodic reaction of said electroplating solution; said electroplating solution having an electrodeposition characteristic of percentage of said alloying agent deposited cathodically from said solution versus frequency of said applied alternating current exhibiting a given slope in a first portion over a given low range of frequencies, a slope greater than said given slope in a second portion over a middle range of higher frequencies, and a slope less than said greater slope in a third portion over a still higher range of frequencies; an depositing a given composition of said electrodeposited film by establishing the frequency of said applied alternating current at a value in said middle range of higher frequencies of said characteristic.
Claim 3
Dependent Claim
15 words
Method as set forth in claim 1 wherein Fe-Ni film is 20-80 weight percent composition.
Claim 4
Dependent Claim
21 words
Method as set forth in claim 2 wherein said frequency is approximately in the range of 20 Hz to 100 Hz.
Claim 5
Dependent Claim
35 words
Method as set forth in claim 2 wherein said frequency is established in the range of approximately 60 Hz to 100 Hz and said temperature is established in the range of approximately 25*C to 40*C.
Claim 6
Dependent Claim
43 words
Method as set forth in claim 1 wherein said Fe-Ni alloy film has weight percent composition of Fe/Ni of 20/80 and said solution has molar concentration of said Fe to molar concentration of said Ni approximately in the range of 20/80 to 5/95.
Claim 7
Dependent Claim
67 words
Method as set forth in claim 1 wherein said solution includes NiSO4 . 6H2O 6.3 g/l, FeSO4 . 7H2O 1.7 g/l, NaK-tartrate 10.0 g/l; said pH 3.0 at approximately 25*C; said direct current Id-c 2 ma/cm2; said peak value of said alternating current Ip 13.7 ma/cm2; and said frequency of said alternating current f 25 Hz; whereby the rate of deposition of said alloy film Rate 22A/min.
Claim 8
Dependent Claim
68 words
Method as set forth in claim 1 wherein said solution includes NiSO4 . 6H2O 30.0 g/l, FeSO4 . 7H2O 1.7 g/l, NaK tartrate 10.0 g/l; said pH 3.0 at approximately 25*C; said direct current Id-c 2 ma/cm2; said peak value of said alternating current Ip 13.7 ma/cm2; and said frequency of said alternating current f 100 Hz; whereby the rate of deposition of said alloy film Rate 125A/min.
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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) | 1976-02-13 | 1976-08-14 | 1977-02-13 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1980-02-13 | 1980-08-14 | 1981-02-13 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1984-02-13 | 1984-08-14 | 1985-02-13 | $7700.00 | Window Closed / Lapsed |