US4465564A
Expired / Lapsed
US
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Gold plating bath containing tartrate and carbonate salts
Assignee: AMERICAN CHEMICAL & REFINING COMPANY Inc 36 SHEFFIELD ST WATERBURY CT 06720 A CORP OF CT
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Filing: 1983-06-27
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Granted: 1984-08-14
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Expires: 2003-06-27
Abstract
Abstract A bath for electrodepositing gold utilizes, as the essential ingredients of its electrolyte, salts providing the tartrate radical and the carbonate radical. The bath will have a pH value ranging from approximately neutral to highly alkaline, and adjustments to lower the pH will most advantageously be made utilizing tartaric acid. The bath operates with relatively low gold concentrations, and is capable of producing highly pure deposits and highly desirable alloy deposits; it is especially well suited for semi-conductor industry applications.
Inventors
- 👤 Augustus Fletcher
- 👤 David N. Cockayne
- 👤 William L. Moriarty
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-30 06:26
CPC Classifications
C; C25; C25D; C25D3/00; C25D3/02; C25D3/56; C25D3/62; C25D3/48; C25D5/00; C25D5/18; C25D5/60; C25D5/623; C25D5/627; Y; Y10; Y10S; Y10S204/00; Y10S204/09
Claims Analysis
Total Claims: 19
Claim 1
Independent Claim
61 words
An aqueous gold plating bath comprising, on a per liter basis: about 0.005 to 0.2 gram mole of gold in solution; a tartrate salt providing about 0.1 to 0.4 gram mole of tartrate radical; and a carbonate salt or acid salt providing about 0.2 to 1.5 gram moles of carbonate radical, said bath having a pH of about 7.5 to 13.0.
Claim 2
Dependent Claim
61 words
An aqueous gold plating bath comprising, on a per liter basis: about 0.005 to 0.2 gram mole of gold in solution; a tartrate salt providing about 0.1 to 0.4 gram mole of tartrate radical; and a carbonate salt or acid salt providing about 0.2 to 1.5 gram moles of carbonate radical, said bath having a pH of about 7.5 to 13.0.
Claim 3
Dependent Claim
62 words
The bath of claim 1 wherein the concentration of gold in solution is about 0.02 to 0.06 gram mole, the concentration of the tartrate salt provides about 0.2 to 0.3 gram mole of the tartrate radical, the concentration of the carbonate salt provides about 0.2 to 0.7 gram mole of the carbonate radical, and said pH value is about 8.0 to 11.0.
Claim 4
Dependent Claim
62 words
The bath of claim 1 wherein the concentration of gold in solution is about 0.02 to 0.06 gram mole, the concentration of the tartrate salt provides about 0.2 to 0.3 gram mole of the tartrate radical, the concentration of the carbonate salt provides about 1.0 to 1.5 gram mole of the carbonate radical, and said pH value is about 8.0 to 11.0.
Claim 5
Dependent Claim
29 words
The bath of claim 1 additionally comprising a minor amount of a metallic additive selected from the group consisting of thallium, arsenic, copper, cadmium, zinc, palladium, and mixtures thereof.
Claim 6
Dependent Claim
23 words
The bath of claim 4 additionally including an additive selected from the group consisting of polyethyleneimine, potassium cyanide, sodium borate, and mixtures thereof.
Claim 7
Dependent Claim
23 words
The bath of claim 1 additionally including an additive selected from the group consisting of polyethyleneimine, potassium cyanide, sodium borate, and mixtures thereof.
Claim 8
Independent Claim
117 words
A method for electroplating gold comprising the steps of: A. immersing a workpiece in a bath comprising, on a per liter basis, about 0.005 to 0.2 gram mole of gold in solution, a tartrate salt providing about 0.1 to 0.4 gram mole of tartrate radical, a carbonate salt providing about 0.2 to 1.5 gram mole of carbonate radical, said bath having a pH value of about 7.5 to 13.0 and a temperature of about 35° to 85° C.; and B. applying an electrical potential across the workpiece and an anode to provide a current density of about 1.0 to 750 amperes per square foot at said workpiece, to thereby effect the desired thickness of electrodeposited metal thereon.
Claim 9
Independent Claim
117 words
A method for electroplating gold comprising the steps of: A. immersing a workpiece in a bath comprising, on a per liter basis, about 0.005 to 0.2 gram mole of gold in solution, a tartrate salt providing about 0.1 to 0.4 gram mole of tartrate radical, a carbonate salt providing about 0.2 to 1.5 gram mole of carbonate radical, said bath having a pH value of about 7.5 to 13.0 and a temperature of about 35° to 85° C.; and B. applying an electrical potential across the workpiece and an anode to provide a current density of about 1.0 to 750 amperes per square foot at said workpiece, to thereby effect the desired thickness of electrodeposited metal thereon.
Claim 10
Dependent Claim
14 words
The method of claim 7 wherein said potential is applied by continuous direct current.
Claim 11
Dependent Claim
14 words
The method of claim 7 wherein said potential is applied by pulsed direct current.
Claim 12
Dependent Claim
25 words
The method of claim 7 including the additional step of adjusting the pH to said value by the introduction of tartaric acid into said bath.
Claim 13
Dependent Claim
82 words
As a gold electroplating bath, a solution consisting essentially of about 30 to 60 grams of potassium tartrate, about 30 to 60 grams of potassium carbonate, about 1.5 grams of tartaric acid, about 8 to 12 grams of gold metal, zero to 30 grams of potassium cyanide, zero or an effective amount of an additive selected from the group consisting of thallium, arsenic, copper, cadmium, zinc, palladium, sodium borate, polyethyleneimine, and mixtures thereof, and sufficient water to form one liter of solution.
Claim 14
Dependent Claim
82 words
As a gold electroplating bath, a solution consisting essentially of about 30 to 60 grams of potassium tartrate, about 30 to 60 grams of potassium carbonate, about 1.5 grams of tartaric acid, about 8 to 12 grams of gold metal, zero to 30 grams of potassium cyanide, zero or an effective amount of an additive selected from the group consisting of thallium, arsenic, copper, cadmium, zinc, palladium, sodium borate, polyethyleneimine, and mixtures thereof, and sufficient water to form one liter of solution.
Claim 15
Dependent Claim
27 words
The bath of claim 11 from which potassium cyanide is omitted, and in which the amounts of potassium tartrate and potassium carbonate included are both 60 grams.
Claim 16
Dependent Claim
16 words
The bath of claim 11 in which said additive comprises copper, cadmium, and polyethyleneimine, in combination.
Claim 17
Dependent Claim
15 words
The bath of claim 11 in which said additive comprises copper and palladium, in combination.
Claim 18
Dependent Claim
37 words
As a gold electroplating bath, a solution consisting essentially of about 60 grams of potassium tartrate, about 120 grams of potassium carbonate, about 8 grams of gold metal, and sufficient water to form one liter of solution.
Claim 19
Dependent Claim
37 words
As a gold electroplating bath, a solution consisting essentially of about 60 grams of potassium tartrate, about 120 grams of potassium carbonate, about 8 grams of gold metal, and sufficient water to form one liter of solution.
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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) | 1987-08-14 | 1988-02-13 | 1988-08-14 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1991-08-14 | 1992-02-13 | 1992-08-14 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1995-08-14 | 1996-02-13 | 1996-08-14 | $7700.00 | Window Closed / Lapsed |