Patent US4469567A successfully refreshed from Google Patents.
US4469567A
Expired / Lapsed
US
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Treatment of copper foil
Assignee: ELECTROFOILS TECHNOLOGY Ltd
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Filing: 1983-12-01
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Granted: 1984-09-04
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Expires: 2003-12-01
Abstract
Abstract A method of treating copper foil for use in the production of printed circuit boards to improve the adhesion of the foil to a base material includes the steps of depositing a nodular or dendritic layer of metal such as copper or zinc onto the foil and encapsulating said nodular or dendritic layer of metal with a layer of copper. A barrier layer is deposited over said encapsulating layer of copper, the barrier layer comprising an alloy of zinc, nickel and one or more of the metals lead, selenium, tellurium, tin or arsenic, the resultant structure then being passivated.
Inventors
- 👤 John Torday
- 👤 James McGilly
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-30 16:42
CPC Classifications
H; H05; H05K; H05K3/00; H05K3/38; H05K3/382; H05K3/384; C; C25; C25D; C25D3/00; C25D3/02; C25D3/56; C25D3/565; C25D5/00; C25D5/10; C25D5/48; C25D5/60; C25D5/605; C25D5/611; C25D5/627; H05K2201/00; H05K2201/03; H05K2201/0332; H05K2201/0335; H05K2201/0355; H05K2203/00; H05K2203/03; H05K2203/0307; H05K2203/07; H05K2203/0703; H05K2203/0723
Claims Analysis
Total Claims: 11
Claim 1
Independent Claim
68 words
A method of treating copper foil including the steps of electrodepositing onto the foil a nodular, dendritic layer of metal, encapsulating said nodular, dendritic layer of metal with a layer of copper, applying over said encapsulating layer a barrier layer comprising an alloy of zinc, nickel and at least one of the metals selected from the group lead, selenium, tellurium, tin and arsenic, and passivating the resultant structure.
Claim 2
Independent Claim
68 words
A method of treating copper foil including the steps of electrodepositing onto the foil a nodular, dendritic layer of metal, encapsulating said nodular, dendritic layer of metal with a layer of copper, applying over said encapsulating layer a barrier layer comprising an alloy of zinc, nickel and at least one of the metals selected from the group lead, selenium, tellurium, tin and arsenic, and passivating the resultant structure.
Claim 3
Dependent Claim
29 words
A method according to claim 1 in which the barrier layer contains between 0.1% and 4% of lead and between 5% and 25% of nickel, the balance being zinc.
Claim 4
Dependent Claim
33 words
A method according to claim 2 in which the barrier layer is electroplated from a bath containing nickel sulphate, zinc sulphate, ammonia, a citrate and lead in solution using a stainless steel anode.
Claim 5
Dependent Claim
32 words
A method according to claim 2 in which the barrier layer is electroplated from a bath containing nickel sulphate, zinc sulphate, ammonia, a citrate and lead in solution using a nickel anode.
Claim 6
Dependent Claim
29 words
A method according to claim 2 in which the barrier layer is electroplated from a bath containing nickel sulphate, zinc sulphate, ammonia and a citrate using a lead anode.
Claim 7
Dependent Claim
16 words
A method according to claim 1 in which passivation is achieved by means of chromate dipping.
Claim 8
Dependent Claim
20 words
A method according to claim 1 in which passivation is achieved by means of cathodic electrolysis of a chromate solution.
Claim 9
Dependent Claim
19 words
A method according to claim 1 in which the nodular, dendritic layer deposited onto the copper foil is copper.
Claim 10
Dependent Claim
19 words
A method according to claim 1 in which the nodular, dendritic layer deposited onto the copper foil is zinc.
Claim 11
Dependent Claim
20 words
A laminate comprising a dielectric substrate to which is bonded copper foil treated according to the method of claim 1.
References Cited (Backward Citations)
US3857681A
Cited
US4282073A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1987-09-04 | 1988-03-05 | 1988-09-04 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1991-09-04 | 1992-03-05 | 1992-09-04 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1995-09-04 | 1996-03-05 | 1996-09-04 | $7700.00 | Window Closed / Lapsed |