US5250363A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Chromium-zinc anti-tarnish coating for copper foil having a dark color
Assignee: GBC Metals LLC
•
Filing: 1992-10-26
•
Granted: 1993-10-05
•
Expires: 2012-10-26
Abstract
Abstract A technique for improving the tarnish and oxidation resistance of metallic substrate is disclosed. The substrate is immersed in an aqueous solution containing sodium hydroxide, zinc ions and chromium (VI) ions. Either the temperature of the aqueous solution or the current density is selected so that at least one surface of the substrate is coated with a nontransparent layer. A chromium-zinc coating is electrolytically applied. The coating provides tarnish resistance at temperatures in excess of 230 DEG C. The coating is removable by immersion in sulfuric acid. Improved results are obtained by rinsing deionized water containing a small amount of an alkaline or alkaline earth hydroxide.
Inventors
- 👤 Szuchain F. Chen
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-02 09:01
CPC Classifications
C; C25; C25D; C25D3/00; C25D3/02; C25D3/56; H; H05; H05K; H05K3/00; H05K3/38; H05K3/382; H05K3/384; H05K2201/00; H05K2201/03; H05K2201/0332; H05K2201/0335; H05K2201/0355; H05K2203/00; H05K2203/07; H05K2203/0703; H05K2203/0723; H05K3/22; H05K3/24; H05K3/244; Y; Y10; Y10S; Y10S428/00; Y10S428/922; Y10S428/9335; Y10S428/934; Y10S428/935; Y10T; Y10T428/00; Y10T428/12; Y10T428/12431; Y10T428/12438; Y10T428/12493; Y10T428/12771; Y10T428/12785; Y10T428/12792; Y10T428/12861; Y10T428/12903
Claims Analysis
Total Claims: 24
Claim 1
Independent Claim
54 words
A composite material, comprising: a copper or copper alloy substrate having first and second sides; a first anti-tarnish layer deposited on at least said first side, said first anti-tarnish layer being a nontransparent layer of co-deposited chromium and zinc having a zinc to chromium ratio in excess of about 13 to 1, by weight.
Claim 2
Dependent Claim
54 words
A composite material, comprising: a copper or copper alloy substrate having first and second sides; a first anti-tarnish layer deposited on at least said first side, said first anti-tarnish layer being a nontransparent layer of co-deposited chromium and zinc having a zinc to chromium ratio in excess of about 13 to 1, by weight.
Claim 3
Dependent Claim
16 words
The composite material of claim 1 further including a second anti-tarnish layer adjacent said second side.
Claim 4
Dependent Claim
13 words
The composite coating of claim 2 wherein said second anti-tarnish layer is transparent.
Claim 5
Dependent Claim
24 words
The composite material of claim 3 wherein said second anti-tarnish layer has a zinc to chromium ratio of from about 5:1 to about 12:1.
Claim 6
Dependent Claim
27 words
The composite coating of claim 3 wherein said first side has a dendritic layer disposed between said copper or copper alloy substrate and said first coating layer.
Claim 7
Dependent Claim
23 words
The composite material of claim 5 wherein said first side has a zinc to chromium ratio of from about 13:1 to about 18:1.
Claim 8
Dependent Claim
117 words
An electrolytic process for applying a codeposited chromium and zinc anti-tarnish layer on at least one side of a copper or copper alloy substrate in an electrolytic cell having: first and second anodes in spaced relationship; an electrolyte containing an aqueous solution of hydroxide, zinc and chromium ions; and said copper or copper alloy substrate positioned between said first and second anodes and acting as the cathode; which process comprises impressing a first current density through said first anode and a second current density through said second anode and maintaining the temperature of said electrolyte to be effective to deposit a nontransparent anti-tarnish layer on said at least one side of said copper or copper alloy substrate.
Claim 9
Dependent Claim
117 words
An electrolytic process for applying a codeposited chromium and zinc anti-tarnish layer on at least one side of a copper or copper alloy substrate in an electrolytic cell having: first and second anodes in spaced relationship; an electrolyte containing an aqueous solution of hydroxide, zinc and chromium ions; and said copper or copper alloy substrate positioned between said first and second anodes and acting as the cathode; which process comprises impressing a first current density through said first anode and a second current density through said second anode and maintaining the temperature of said electrolyte to be effective to deposit a nontransparent anti-tarnish layer on said at least one side of said copper or copper alloy substrate.
Claim 10
Dependent Claim
18 words
The process of claim 7 wherein said electrolyte temperature is from about 50° C. to about 90° C.
Claim 11
Dependent Claim
18 words
The process of claim 8 wherein said electrolyte temperature is from about 60° C. to about 80° C.
Claim 12
Dependent Claim
113 words
An electrolytic process for applying a co-deposited chromium and zinc anti-tarnish layer on at least one side of a copper or copper alloy substrate in an electrolytic cell having: first and second anodes in spaced relationship; an electrolyte containing an aqueous solution of hydroxide, zinc and chromium ions; and said copper or copper alloy substrate positioned between said first and second anodes and acting as the cathode; which process comprises impressing a first current density through said first anode and a second current density through said second anode, said first current density being effective to deposit a nontransparent anti-tarnish layer on said at least one side of said copper or copper alloy substrate.
Claim 13
Dependent Claim
113 words
An electrolytic process for applying a co-deposited chromium and zinc anti-tarnish layer on at least one side of a copper or copper alloy substrate in an electrolytic cell having: first and second anodes in spaced relationship; an electrolyte containing an aqueous solution of hydroxide, zinc and chromium ions; and said copper or copper alloy substrate positioned between said first and second anodes and acting as the cathode; which process comprises impressing a first current density through said first anode and a second current density through said second anode, said first current density being effective to deposit a nontransparent anti-tarnish layer on said at least one side of said copper or copper alloy substrate.
Claim 14
Dependent Claim
19 words
The process of claim 10 wherein said first current density is in excess of about 15 mA/cm 2 .
Claim 15
Dependent Claim
12 words
The process of claim 11 wherein said second current density is zero.
Claim 16
Dependent Claim
21 words
The process of claim 11 wherein said second current density is sufficiently low such that said second anti-tarnish layer is transparent.
Claim 17
Dependent Claim
39 words
The process of claim 13 including the step of forming a plurality of dendrites on the surface of said metallic substrate to be most proximate to said first anode prior to imparting said metallic substrate with an anti-tarnish coating.
Claim 18
Dependent Claim
22 words
The process of claim 14 wherein said second current density is from about 3 mA/cm 2 to about 10 mA/cm 2 .
Claim 19
Dependent Claim
22 words
The process of claim 16 wherein said first current density is from about 30 mA/cm 2 to about 50 mA/cm 2 .
Claim 20
Dependent Claim
41 words
A laminate comprising: a dielectric substrate; a copper or copper alloy foil having first and second sides, said first side laminated to said dielectric; and a nontransparent chromium-zinc layer deposited between said dielectric substrate and said copper or copper alloy foil.
Claim 21
Dependent Claim
41 words
A laminate comprising: a dielectric substrate; a copper or copper alloy foil having first and second sides, said first side laminated to said dielectric; and a nontransparent chromium-zinc layer deposited between said dielectric substrate and said copper or copper alloy foil.
Claim 22
Dependent Claim
20 words
The laminate of claim 17 wherein said chromium-zinc layer has a zinc to chromium ratio in excess of about 13:1.
Claim 23
Dependent Claim
17 words
The laminate of claim 17 wherein said zinc to chromium ratio is from about 13:1 to 18:1.
Claim 24
Dependent Claim
20 words
A laminate of claim 17 wherein said copper or copper alloy foil is patterned into a plurality of circuit traces.
References Cited (Backward Citations)
SU328208A1
Cited
US2030601A
Cited
US2080891A
Cited
US2412543A
Cited
US2364993A
Cited
US2415651A
Cited
US2460896A
Cited
US2418806A
Cited
US2481854A
Cited
US2647865A
Cited
US3198672A
Cited
US3106484A
Cited
US3323881A
Cited
US3585010A
Cited
US3625844A
Cited
US4203809A
Cited
US3677828A
Cited
US3716427A
Cited
US3857681A
Cited
US3764400A
Cited
US3816142A
Cited
US3853716A
Cited
US3857683A
Cited
US4048381A
Cited
US4064320A
Cited
US4049481A
Cited
US4131517A
Cited
US4127438A
Cited
GB2030176A
Cited
US4376154A
Cited
GB2073779A
Cited
US4495008A
Cited
US4407900A
Cited
US4386139A
Cited
US4358479A
Cited
US4456508A
Cited
US4387006A
Cited
US4468293A
Cited
US4432846A
Cited
US4515671A
Cited
US4497876A
Cited
US4640747A
Cited
US4702802A
Cited
US4642161A
Cited
US4572768A
Cited
US4647315A
Cited
US4702793A
Cited
US4775444A
Cited
US4902551A
Cited
US4939316A
Cited
US4997516A
Cited
US5098796A
Cited
US5037482A
Cited
US5006200A
Cited
US5022968A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1996-10-04 | 1997-04-05 | 1997-10-05 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 2000-10-04 | 2001-04-05 | 2001-10-05 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2004-10-04 | 2005-04-05 | 2005-10-05 | $7700.00 | Window Closed / Lapsed |