Patent US4049481A successfully refreshed from Google Patents.
US4049481A
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Surface treatment method of copperfoil
Assignee: Mitsui Kinzoku Co Ltd
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Filing: 1976-06-16
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Granted: 1977-09-20
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Expires: 1996-06-16
Abstract
Abstract The present invention relates to a method of treatment on the surface of copperfoil mainly used for printed circuits. More particularly, it relates to a method of electrodeposition of a binary alloy consisting of zinc and tin as a barrier layer against copper migration into an adhesive substrate during subsequent heat press lamination, while a binary alloy on copperfoil is converted to ternary alloy defusing into copper by heat press lamination resulting in a layer of Cu-Zn-Sn, ternary alloy. This layer prevents spottings on the etched surfaces and provides high resistance to hydrochloric acid, and better adhesion than hitherto used alloys.
Inventors
- 👤 Shigeyoshi Morisaki
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-24 10:31
CPC Classifications
H; H05; H05K; H05K3/00; H05K3/38; H05K3/382; H05K3/384; C; C25; C25D; C25D3/00; C25D3/02; C25D3/56; C25D3/565; H05K2201/00; H05K2201/03; H05K2201/0332; H05K2201/0335; H05K2201/0355; H05K2203/00; H05K2203/03; H05K2203/0307; H05K2203/07; H05K2203/0703; H05K2203/0723; H05K2203/11; H05K2203/1105; Y; Y10; Y10S; Y10S428/00; Y10S428/901; Y10T; Y10T428/00; Y10T428/12; Y10T428/12493; Y10T428/12708; Y10T428/12715; Y10T428/12771; Y10T428/12785; Y10T428/12792; Y10T428/24; Y10T428/24802; Y10T428/24917
Claims Analysis
Total Claims: 6
Claim 1
Independent Claim
98 words
A method for surface treatment of copper foil used for printed circuit boards comprising the steps of subjecting a nodularized surface of copper foil to electrodeposition thereon of a thin layer of zinc and tin alloy in which the tin content is from about 5 to 20%, and at a thickness of from 0.03μ to 0.15μ, and adhering the alloy-covered surface of the nodularized copper foil thus obtained to a resinous laminate by heat and pressure until a layer of a ternary alloy of zinc, tin and copper is formed between said copper foil and said resinous laminate.
Claim 2
Independent Claim
98 words
A method for surface treatment of copper foil used for printed circuit boards comprising the steps of subjecting a nodularized surface of copper foil to electrodeposition thereon of a thin layer of zinc and tin alloy in which the tin content is from about 5 to 20%, and at a thickness of from 0.03μ to 0.15μ, and adhering the alloy-covered surface of the nodularized copper foil thus obtained to a resinous laminate by heat and pressure until a layer of a ternary alloy of zinc, tin and copper is formed between said copper foil and said resinous laminate.
Claim 3
Dependent Claim
22 words
A method as claimed in claim 1, wherein the thickness of the layer of zinc and tin alloy is about 0.08μ .
Claim 4
Dependent Claim
24 words
A method as claimed in claim 1, wherein tin content of the thin layer of zinc and tin alloy is from 5 to 15%.
Claim 5
Dependent Claim
54 words
A method as claimed in claim 1, wherein the zinc and tin alloy surface deposited on the nodularized copper foil is adhered to the resinous laminate by maintaining the same for about 1 hour at a temperature of from 150° C. to 170° C. and pressure of from 15 to 20 kg/cm 2 .
Claim 6
Dependent Claim
26 words
A method as claimed in claim 1 wherein a solution for electrodeposition of said zinc and tin alloy comprises potassium pyrophosphate, zinc pyrophosphate and tin pyrophosphate.
References Cited (Backward Citations)
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1980-09-19 | 1981-03-21 | 1981-09-20 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1984-09-19 | 1985-03-21 | 1985-09-20 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1988-09-19 | 1989-03-21 | 1989-09-20 | $7700.00 | Window Closed / Lapsed |