US4402998A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Method for providing an adherent electroless metal coating on an epoxy surface
Assignee: AT&T Inc
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Filing: 1982-09-24
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Granted: 1983-09-06
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Expires: 2002-09-24
Abstract
Abstract A method of electrolessly plating a substrate having a rubber-modified epoxy surface includes the steps of preheating the substrate and while still warm, sputter etching at least 50A. from its surface. The substrate is then vacuum metalized with an adhesion promoting metal film, coated with a catalytic layer and a metal is electrolessly deposited thereover.
Inventors
- 👤 Henry Y. Kumagai
- 👤 Daniel J. Shanefield
- 👤 Fred W. Verdi
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-26 16:10
CPC Classifications
H; H05; H05K; H05K3/00; H05K3/38; H05K3/381; C; C23; C23C; C23C18/00; C23C18/16; C23C18/1601; C23C18/1603; C23C18/1605; C23C18/18; C23C18/20; C23C18/2006; C23C18/2026; C23C18/2033; C23C18/2046; C23C18/2073; C23C18/208; H05K3/02; H05K3/04; H05K3/046; H05K3/048; H05K3/388; H05K2201/00; H05K2201/03; H05K2201/0332; H05K2201/0335; H05K2201/0347; H05K2203/00; H05K2203/09; H05K2203/095; H05K3/386; H05K3/40; H05K3/4038; H05K3/4076; H05K3/42; H05K3/425; H05K3/426
Claims Analysis
Total Claims: 12
Claim 1
Independent Claim
116 words
A method of forming an adherent electrolessly deposited film on a rubber-modified epoxy resin surface or a surface comprising an epoxy resin having a high degree of unsaturation excluding aromatic unsaturation, comprises the steps of: (a) baking the substrate so as to degas the surface, and while still warm subjecting the substrate to a vacuum; (b) while evacuated, sputter etching at least 50 A. from the surface of the substrate; (c) vacuum metallizing an adherent thin metallic chromium film over the substrate; (d) depositing a second metallic layer which is catalytic to a subsequent electroless deposition over the adherent metal film; and (e) electrolessly plating a thick metallic layer over the metallized portions of the substrate.
Claim 2
Independent Claim
116 words
A method of forming an adherent electrolessly deposited film on a rubber-modified epoxy resin surface or a surface comprising an epoxy resin having a high degree of unsaturation excluding aromatic unsaturation, comprises the steps of: (a) baking the substrate so as to degas the surface, and while still warm subjecting the substrate to a vacuum; (b) while evacuated, sputter etching at least 50 A. from the surface of the substrate; (c) vacuum metallizing an adherent thin metallic chromium film over the substrate; (d) depositing a second metallic layer which is catalytic to a subsequent electroless deposition over the adherent metal film; and (e) electrolessly plating a thick metallic layer over the metallized portions of the substrate.
Claim 3
Dependent Claim
37 words
The method recited in claim 1, wherein the adherent thin metallic film is in the order of about 1 microinch thick and the catalytic metallic layer thereover is in the order of about 10 microinches in thickness.
Claim 4
Dependent Claim
23 words
The method recited in claim 1, wherein the substrate is baked at elevated temperatures in the order of about 120° C. in air.
Claim 5
Dependent Claim
17 words
The method recited in claim 1, wherein the metallic layers are sputter deposited onto the etched substrate.
Claim 6
Dependent Claim
14 words
The method recited in claim 1, wherein the catalytic metal is copper or nickel.
Claim 7
Independent Claim
158 words
A method of forming a printed circuit board on a substrate having a plurality of spaced through-holes and a substrate surface comprising a rubber-modified epoxy resin or an epoxy resin having a high degree of unsaturation excluding aromatic unsaturation comprising the steps of: (a) forming a resist pattern on the substrate conforming to the negative of the desired circuit pattern; (b) baking the substrate so as to degas the surface and while still warm subjecting the substrate to a vacuum; (c) sputter etching at least 50 A. from the surface of the patterned substrate; (d) vacuum metallizing an adherent thin metallic chromium film over the entire substrate; (e) depositing a thicker primary metallic layer which is catalytic to subsequent electroless deposition over the adherent metallic film; (f) stripping the photoresist together with its overlying metal films; and (g) electrolessly plating a thick metallic layer over the remaining metallic pattern in a thickness sufficient to give suitable electrical conductivity.
Claim 8
Independent Claim
158 words
A method of forming a printed circuit board on a substrate having a plurality of spaced through-holes and a substrate surface comprising a rubber-modified epoxy resin or an epoxy resin having a high degree of unsaturation excluding aromatic unsaturation comprising the steps of: (a) forming a resist pattern on the substrate conforming to the negative of the desired circuit pattern; (b) baking the substrate so as to degas the surface and while still warm subjecting the substrate to a vacuum; (c) sputter etching at least 50 A. from the surface of the patterned substrate; (d) vacuum metallizing an adherent thin metallic chromium film over the entire substrate; (e) depositing a thicker primary metallic layer which is catalytic to subsequent electroless deposition over the adherent metallic film; (f) stripping the photoresist together with its overlying metal films; and (g) electrolessly plating a thick metallic layer over the remaining metallic pattern in a thickness sufficient to give suitable electrical conductivity.
Claim 9
Dependent Claim
37 words
The method recited in claim 6, wherein the adherent thin metallic film is in the order of about 1 microinch thick and the primary metallic layer thereover is in the order of about 10 microinches in thickness.
Claim 10
Dependent Claim
28 words
The method recited in claim 6, wherein the primary metallic layer is electrolessly plated over the adherent thin metallic film which film is catalytic to the electroless plating.
Claim 11
Dependent Claim
17 words
The method recited in claim 6, wherein the substrate is baked in air at about 120° C.
Claim 12
Dependent Claim
38 words
The method recited in claim 6, wherein the substrate is supported on a carrier plate during vacuum etching and deposition in a manner so as to be raised from the carrier plate by between 1/4 and 3/8 inch.
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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) | 1986-09-05 | 1987-03-07 | 1987-09-06 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1990-09-05 | 1991-03-07 | 1991-09-06 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1994-09-05 | 1995-03-07 | 1995-09-06 | $7700.00 | Window Closed / Lapsed |