US4076599A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Method and composition for plating palladium
Assignee: International Business Machines Corp
•
Filing: 1976-08-24
•
Granted: 1978-02-28
•
Expires: 1996-08-24
Abstract
Abstract This invention relates to the palladium plating of electrical parts, such as frames, pins, connectors and in general various types of electrical contacts. More particularly, this invention relates to a method and composition for high speed electroplating of uniform, bright palladium deposits over a wide operating current density range using a palladosammine chloride plating bath to which sodium sulfite has been added. The method is adapted for rack plating of parts having an irregular shaped configuration as well as those having a uniform configuration.
Inventors
- 👤 Jerome Joseph Caricchio, Jr.
- 👤 Edward Robert York
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-29 17:46
CPC Classifications
C; C25; C25D; C25D3/00; C25D3/02; C25D3/50
Claims Analysis
Total Claims: 21
Claim 1
Independent Claim
147 words
A method for depositing palladium on a substrate by electrolysis comprising the steps of: subjecting an anode to an aqueous bath solution having a pH of about 8.5 to 9.6 and consisting essentially of 20-30 grams/liter of pallados-ammine chloride, 30-60 grams/liter of ammonium chloride, 30-40 grams/liter of ammonium sulfamate, 50-100 cc/liter of concentrated ammonium hydroxide, to maintain the pH of the bath at about a pH of 8.5 to 9.6, and 1-1000 parts/million of a sulfite ion concentration derived from an alkali metal sulfite or ammonium sulfite; immersing the substrate to be coated as a cathode in said solution and in spaced relation to said anode; applying a potential difference between said anode and said substrate to obtain a current density of 3-30 amps/ft 2 at the cathode; agitating both said solution and substrate; and maintaining said solution at a temperature of about 72° to 82° F.
Claim 2
Independent Claim
147 words
A method for depositing palladium on a substrate by electrolysis comprising the steps of: subjecting an anode to an aqueous bath solution having a pH of about 8.5 to 9.6 and consisting essentially of 20-30 grams/liter of pallados-ammine chloride, 30-60 grams/liter of ammonium chloride, 30-40 grams/liter of ammonium sulfamate, 50-100 cc/liter of concentrated ammonium hydroxide, to maintain the pH of the bath at about a pH of 8.5 to 9.6, and 1-1000 parts/million of a sulfite ion concentration derived from an alkali metal sulfite or ammonium sulfite; immersing the substrate to be coated as a cathode in said solution and in spaced relation to said anode; applying a potential difference between said anode and said substrate to obtain a current density of 3-30 amps/ft 2 at the cathode; agitating both said solution and substrate; and maintaining said solution at a temperature of about 72° to 82° F.
Claim 3
Dependent Claim
17 words
The method set forth in claim 1 wherein there is maintained a pH in the 9.0-9.5 region.
Claim 4
Dependent Claim
18 words
The method set forth in claim 1 wherein the bath solution contains 3-1000 parts/million of sulfite ion concentration.
Claim 5
Dependent Claim
24 words
The method set forth in claim 1 wherein the bath consists of said palladosammine chloride, ammonium chloride, ammonium sulfamate, ammonium hydroxide and sodium sulfite.
Claim 6
Dependent Claim
13 words
The method of claim 1 wherein said substrate is formed of beryllium-copper alloy.
Claim 7
Dependent Claim
16 words
The method of claim 1 wherein said substrate is nickel plated prior to being palladium plated.
Claim 8
Dependent Claim
49 words
The method of claim 1 wherein the bath consists of 21 to 27 g/l palladosammine chloride, 40-45 g/l of ammonium chloride, 31 to 33 g/l of ammonium sulfamate, sufficient concentrated ammonium hydroxide to maintain a pH of about 9.10 to 9.40 and 2 to 200 parts/million of sodium sulfite.
Claim 9
Independent Claim
149 words
A method for depositing palladium on a substrate by electrolysis comprising the steps of: subjecting an anode to an aqueous bath solution having a pH of about 9.0 to 9.4 and consisting essentially of 20-30 grams/liter of pallados-ammine chloride, 30-60 grams/liter of ammonium chloride, 30-40 grams/liter of ammonium sulfamate, 50-100 cc/liter of concentrated ammonium hydroxide, to maintain the pH of the bath at about a pH of 9.0 to 9.4, and 1-1000 parts/million of a sulfite ion concentration derived from an alkali metal sulfite or ammonium sulfite; immersing the substrate to be coated as a cathode in said solution and in spaced relation to said anode; applying a potential difference between said anode and said substrate to obtain a current density of 15-25 amps/ft 2 for 4-5.5 minutes at the cathode; agitating both said solution and substrate; and maintaining said solution at a temperature of about 72° to 82°F.
Claim 10
Independent Claim
149 words
A method for depositing palladium on a substrate by electrolysis comprising the steps of: subjecting an anode to an aqueous bath solution having a pH of about 9.0 to 9.4 and consisting essentially of 20-30 grams/liter of pallados-ammine chloride, 30-60 grams/liter of ammonium chloride, 30-40 grams/liter of ammonium sulfamate, 50-100 cc/liter of concentrated ammonium hydroxide, to maintain the pH of the bath at about a pH of 9.0 to 9.4, and 1-1000 parts/million of a sulfite ion concentration derived from an alkali metal sulfite or ammonium sulfite; immersing the substrate to be coated as a cathode in said solution and in spaced relation to said anode; applying a potential difference between said anode and said substrate to obtain a current density of 15-25 amps/ft 2 for 4-5.5 minutes at the cathode; agitating both said solution and substrate; and maintaining said solution at a temperature of about 72° to 82°F.
Claim 11
Dependent Claim
23 words
The method set forth in claim 8 wherein the bath solution contains 3-1000 parts/million of a sulfite ion concentration derived from sodium sulfite.
Claim 12
Dependent Claim
26 words
The method set forth in claim 8 wherein the bath consists of said palladosammine chloride, ammonium chloride, ammonium chloride, ammonium sulfamate, ammonium hydroxide and sodium sulfite.
Claim 13
Independent Claim
13 words
The method of clalim 8 wherein said substrate is formed of beryllium-copper alloy.
Claim 14
Independent Claim
13 words
The method of clalim 8 wherein said substrate is formed of beryllium-copper alloy.
Claim 15
Dependent Claim
16 words
The method of claim 8 wherein said substrate is nickel plated prior to being palladium plated.
Claim 16
Dependent Claim
49 words
The method of claim 8 wherein the bath consists of 21 to 27 g/l palladosammine chloride, 40-45 g/l of ammonium chloride, 31 to 33 g/l of ammonium sulfamate, sufficient concentrated ammonium hydroxide to maintain a pH of about 9.10 to 9.40 and 2 to 200 parts/million of sodium sulfite.
Claim 17
Dependent Claim
59 words
An aqueous bath solution for the electro-plating of palladium consisting essentially of: 20-30 grams/liter of palladosamine chloride; 30-60 grams/liter of ammonium chloride; 30-40 grams/liter of ammonium sulfamate; 50-100 cc/liter of concentrated ammonium hydroxide so that said bath has a pH of about 8.5 to 9.6; and 1-1000 parts/million of a sulfite ion concentration derived from an alkali metal sulfite.
Claim 18
Dependent Claim
59 words
An aqueous bath solution for the electro-plating of palladium consisting essentially of: 20-30 grams/liter of palladosamine chloride; 30-60 grams/liter of ammonium chloride; 30-40 grams/liter of ammonium sulfamate; 50-100 cc/liter of concentrated ammonium hydroxide so that said bath has a pH of about 8.5 to 9.6; and 1-1000 parts/million of a sulfite ion concentration derived from an alkali metal sulfite.
Claim 19
Dependent Claim
15 words
The bath solution as set forth in claim 14 and having a pH of 9.0-9.4.
Claim 20
Dependent Claim
17 words
The bath solution as set forth in claim 14 wherein the sulfite ion concentration is 3-1000 parts/million.
Claim 21
Dependent Claim
20 words
The bath solution of claim 14 consisting of said palladosammine chloride, ammonium chloride, ammonium sulfamate, ammonium hydroxide and sodium sulfite.
References Cited (Backward Citations)
SU254987A1
Cited
US3150065A
Cited
US3637474A
Cited
US3933602A
Cited
US3925170A
Cited
US3920526A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1981-02-27 | 1981-08-29 | 1982-02-28 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1985-02-27 | 1985-08-29 | 1986-02-28 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1989-02-27 | 1989-08-29 | 1990-02-28 | $7700.00 | Window Closed / Lapsed |