Patent US4082591A successfully refreshed from Google Patents.
US4082591A
Expired / Lapsed
US
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Surface treatment process for copper foil
Assignee: Mitsui-Anaconda Electro Copper Sheet Co Ltd
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Filing: 1976-09-28
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Granted: 1978-04-04
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Expires: 1996-09-28
Abstract
Abstract A process is disclosed for preventing oxidative coloring while maintaining good solderability of copper foil wherein a thin layer of tin or a combination of tin and zinc alloy is electro-deposited on the surface of the shiny side of copper foil and the tin or binary alloy diffuses into the surface portion of electrodeposited copper foil by heating, such as drying, baking or lamination under heat and pressure. By virtue of an extremely thin layer of the tin alloy thus formed, the bright tone of the copper surface is maintained during storage or during subsequent lamination of the foil, and the solderability thereof is also improved.
Inventors
- 👤 Shigeyoshi Morisaki
- 👤 Nobuo Kitamura
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-24 23:30
CPC Classifications
H; H05; H05K; H05K3/00; H05K3/22; H05K3/24; H05K3/244; C; C25; C25D; C25D3/00; C25D3/02; C25D3/30; C25D5/00; C25D5/48; C25D5/50; C25D5/505; H05K2201/00; H05K2201/03; H05K2201/0332; H05K2201/0335; H05K2201/0355; H05K2203/00; H05K2203/07; H05K2203/0703; H05K2203/0723
Claims Analysis
Total Claims: 6
Claim 1
Independent Claim
99 words
A process for the surface treatment of copper foil, comprising electrodepositing, in an alkaline bath containing more than 0.3 g. of Sn/l, at a current density of from about 1 to 3 A·sec/dm 2 , on a shiny metallic side of copper foil a thin layer of tin to the extent that the whitish color of the deposited tin is minimized and the reddish color of the copper surface is maintained, followed by heating the foil so produced to diffuse said tin layer into the copper layer and thereby to produce a thin layer of tin and copper alloy.
Claim 2
Dependent Claim
99 words
A process for the surface treatment of copper foil, comprising electrodepositing, in an alkaline bath containing more than 0.3 g. of Sn/l, at a current density of from about 1 to 3 A·sec/dm 2 , on a shiny metallic side of copper foil a thin layer of tin to the extent that the whitish color of the deposited tin is minimized and the reddish color of the copper surface is maintained, followed by heating the foil so produced to diffuse said tin layer into the copper layer and thereby to produce a thin layer of tin and copper alloy.
Claim 3
Dependent Claim
25 words
A process as claimed in claim 1, wherein said copper foil is applied to a substrate with adhesive and is dried by applying heat thereto.
Claim 4
Dependent Claim
24 words
A process as claimed in claim 1, wherein said copper foil is heated during lamination to a substrate under application of heat and pressure.
Claim 5
Dependent Claim
27 words
A process as claimed in claim 1, wherein the alkaline bath contains from about 30 to 300 g/l of a pyrophosphate selected from sodium and potassium pyrophosphate.
Claim 6
Dependent Claim
28 words
A process as claimed in claim 1, wherein the alkaline bath contains from about 10 to 50 g/l of an alkali hydroxide selected from sodium and potassium hydroxide.
References Cited (Backward Citations)
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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) | 1981-04-03 | 1981-10-03 | 1982-04-04 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1985-04-03 | 1985-10-03 | 1986-04-04 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1989-04-03 | 1989-10-03 | 1990-04-04 | $7700.00 | Window Closed / Lapsed |