Patent US4459184A successfully refreshed from Google Patents.
US4459184A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Method for continuous metal deposition from a non-autocatalytic electroless plating bath using electric potential
Assignee: MacDermid Acumen Inc
•
Filing: 1982-06-25
•
Granted: 1984-07-10
•
Expires: 2002-06-25
Abstract
Abstract A method of continuously depositing a metallic plating on the surface of a workpiece from a non-autocatalytic electroless plating bath that is normally inherently self-limiting as to the thickness of metal which can be deposited by electrolessly plating by applying an electric potential on the workpiece in the electroless bath. The method provides non-autocatalytic baths, such as hypophosphite-reduced electroless copper baths, with the ability to plate on nonconductors to a desired thickness which increases with time at a rate dependent on the amount of current applied. A more uniform thickness of deposit over the workpiece being plated and greater deposit penetration into blind holes, deep recesses and tubular portions of complex-shaped parts is obtainable by the method.
Inventors
- 👤 Peter E. Kukanskis
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-04 22:31
CPC Classifications
H; H05; H05K; H05K3/00; H05K3/22; H05K3/24; H05K3/241; C; C23; C23C; C23C18/00; C23C18/16; C23C18/52; C25; C25D; C25D3/00; C25D3/02; C25D3/38; C25D5/00; C25D5/627; C25D7/00; C25D7/12; C25D7/123; H05K3/40; H05K3/42; H05K3/423; H05K3/424; Y; Y10; Y10S; Y10S205/00; Y10S205/916
Claims Analysis
Total Claims: 11
Claim 1
Independent Claim
202 words
A method of continuously depositing a metallic copper plating on the surface of a workpiece comprising the steps of preparing the surface of the workpiece to render it more receptive to the plating, immersing the workpiece in a solution comprising, in addition to water, a soluble source of copper ions, a complexing agent to maintain the copper ions in solution, a reducing agent comprising a soluble source of hypophosphite ions effective to reduce the copper ions to form a metallic copper deposit on the surface of the workpiece when in contact with the solution, the solution being one which is non-autocatalytic and normally inherently produces a metallic deposit of self-limiting thickness, obtaining an electrolessly deposited metallic copper plating on the workpiece through the reduction of the copper ions, applying an electric current of negative potential to the workpiece to render it cathodic while immersed in the solution, completing an electrical circuit by placing an anode in effective electrical contact with the solution, obtaining an electric deposition of copper on the workpiece on the electroless metallic deposition, and depositing copper plating on the workpiece at a thickness which increases with time of immersion in the solution with a substantially constant rate of deposition.
Claim 2
Independent Claim
202 words
A method of continuously depositing a metallic copper plating on the surface of a workpiece comprising the steps of preparing the surface of the workpiece to render it more receptive to the plating, immersing the workpiece in a solution comprising, in addition to water, a soluble source of copper ions, a complexing agent to maintain the copper ions in solution, a reducing agent comprising a soluble source of hypophosphite ions effective to reduce the copper ions to form a metallic copper deposit on the surface of the workpiece when in contact with the solution, the solution being one which is non-autocatalytic and normally inherently produces a metallic deposit of self-limiting thickness, obtaining an electrolessly deposited metallic copper plating on the workpiece through the reduction of the copper ions, applying an electric current of negative potential to the workpiece to render it cathodic while immersed in the solution, completing an electrical circuit by placing an anode in effective electrical contact with the solution, obtaining an electric deposition of copper on the workpiece on the electroless metallic deposition, and depositing copper plating on the workpiece at a thickness which increases with time of immersion in the solution with a substantially constant rate of deposition.
Claim 3
Dependent Claim
44 words
A method of continuously depositing a metallic copper plating on the surface of a workpiece as claimed in claim 1 wherein the electric current applied to the workpiece has a current density ranging from 0.03 to 10 amps per square foot of processing area.
Claim 4
Dependent Claim
34 words
A method of continuously depositing a metallic copper plating on the surface of a workpiece as claimed in claim 1 wherein the workpiece has a catalyzed non-conductive surface prior to immersion in the solution.
Claim 5
Dependent Claim
39 words
A method of continuously depositing a metallic copper plating on the surface of a workpiece as claimed in claim 1 wherein the electric current is not applied until the electroless deposit on the workpiece has reached its self-limiting thickness.
Claim 6
Dependent Claim
162 words
In a method of electrolessly depositing a copper plating on the surface of a workpiece comprising the steps of preparing the surface of the workpiece to render it more receptive to the plating, immersing the workpiece in a solution comprising, in addition to water, a soluble source of cupric ions, a complexing agent to maintain the cupric ions in solution, and a soluble source of hypophosphite ions effective to reduce the cupric ions to metallic copper as a deposit on the surface of the workpiece when in contact with the solution, the improvement therein enabling continuous deposition of the copper plating on the workpiece at a thickness which increases with time of immersion of the workpiece in the solution with a substantially constant rate of deposition comprising applying a negative potential of electric current on the workpiece to render it cathodic while immersed in the solution and completing an electrical circuit by placing an anode in effective electrical contact with the solution.
Claim 7
Dependent Claim
162 words
In a method of electrolessly depositing a copper plating on the surface of a workpiece comprising the steps of preparing the surface of the workpiece to render it more receptive to the plating, immersing the workpiece in a solution comprising, in addition to water, a soluble source of cupric ions, a complexing agent to maintain the cupric ions in solution, and a soluble source of hypophosphite ions effective to reduce the cupric ions to metallic copper as a deposit on the surface of the workpiece when in contact with the solution, the improvement therein enabling continuous deposition of the copper plating on the workpiece at a thickness which increases with time of immersion of the workpiece in the solution with a substantially constant rate of deposition comprising applying a negative potential of electric current on the workpiece to render it cathodic while immersed in the solution and completing an electrical circuit by placing an anode in effective electrical contact with the solution.
Claim 8
Dependent Claim
28 words
The improved method as claimed in claim 5 wherein the electric current has a current density ranging from 0.03 to 10 amps per square foot of processing area.
Claim 9
Dependent Claim
28 words
The improved method as claimed in claim 5 wherein the electric current is not applied until the workpiece has had a metallic copper plating electrolessly deposited on it.
Claim 10
Dependent Claim
27 words
The improved method as claimed in claim 7 wherein the electric current is applied when the electrolessly deposited metallic copper plating has reached a self limiting thickness.
Claim 11
Dependent Claim
19 words
The improved method as claimed in claim 5 wherein the workpiece has a catalyzed non-conductive surface prior to immersion.
References Cited (Backward Citations)
GB1222969A
Cited
US3597266A
Cited
GB1288620A
Cited
US4099974A
Cited
US4086149A
Cited
US4209331A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1987-07-10 | 1988-01-09 | 1988-07-10 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1991-07-10 | 1992-01-09 | 1992-07-10 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1995-07-10 | 1996-01-09 | 1996-07-10 | $7700.00 | Window Closed / Lapsed |