US5106473A
Expired / Lapsed
US
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Process for metallizing a through-hole board
Assignee: Atotech Deutschland GmbH and Co KG
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Filing: 1991-05-03
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Granted: 1992-04-21
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Expires: 2011-05-03
Abstract
Abstract A process is provided for metallizing the hole-wall surface of a through-hole provided in a printed circuit board precursor. In an initial step, the hole-wall surface is pre-treated with an oxidizing agent which micro-roughens it. An electro-conductive polymer film is then formed on the micro-roughened surface by oxidatively polymerizing in situ an acidic solution of an organic monomer with an oxidizing agent previously adsorbed on the board. The polymer film includes dopant anions which are acquired from the monomer solution. Finally, a metal layer is electroplated on the electro-conductive polymer film.
Inventors
- 👤 Keith J. Whitlaw
- 👤 Mark Goodenough
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-29 21:25
CPC Classifications
H; H05; H05K; H05K3/00; H05K3/40; H05K3/42; H05K3/423; H05K3/424; C; C25; C25D; C25D5/00; C25D5/54; C25D5/56; H05K2201/00; H05K2201/03; H05K2201/032; H05K2201/0329; H05K2203/00; H05K2203/07; H05K2203/0779; H05K2203/0783; H05K2203/0786; H05K2203/0796; H05K2203/12; H05K2203/122; H05K3/425; H05K3/427
Claims Analysis
Total Claims: 17
Claim 1
Independent Claim
72 words
A process for metallising a through-hole board comprising the steps of: pre-treating the board with an oxidising agent to micro-roughen its surface, forming an electro-conductive polymer film on the micro-roughened surface by oxidatively polymerizing in situ an acidic solution of an organic monomer with an oxidising agent previously adsorbed on the board, the film incorporating dopant anions acquired from the monomer solution, and electroplating a metal on the electro- conductive polymer film.
Claim 2
Dependent Claim
72 words
A process for metallising a through-hole board comprising the steps of: pre-treating the board with an oxidising agent to micro-roughen its surface, forming an electro-conductive polymer film on the micro-roughened surface by oxidatively polymerizing in situ an acidic solution of an organic monomer with an oxidising agent previously adsorbed on the board, the film incorporating dopant anions acquired from the monomer solution, and electroplating a metal on the electro- conductive polymer film.
Claim 3
Dependent Claim
23 words
A process according to claim 1 wherein the board is treated with a conditioner to soften the surface prior to the oxidising step.
Claim 4
Dependent Claim
31 words
A process according to claim 2 wherein the conditioner is applied to the laminate for about 3-5 minutes and/or the oxidising agent is applied to the laminate for about 5 minutes.
Claim 5
Dependent Claim
35 words
A process according to claim 1 further comprising the steps of neutralising the board after the pre-treatment step and re-oxidising the neutralised board with an oxidising agent capable of being adsorbed by the board's surface.
Claim 6
Dependent Claim
20 words
A process according to claim 4 wherein the organic monomer is pyrrole, furane, aniline or thiophene or a derivative thereof.
Claim 7
Dependent Claim
18 words
A process according to claim 5 wherein the concentration of pyrrole in the acidic solution is 6-25 ml/l.
Claim 8
Dependent Claim
19 words
A process according to claim 1 wherein the acidic solution further comprises gelatin and/or a surfactant and/or an alcohol.
Claim 9
Dependent Claim
20 words
A process according to claim 7 wherein the acidic solution comprises up to 15% by volume of methanol or propanol.
Claim 10
Dependent Claim
22 words
A process according to claim 1 wherein the acidic solution comprises toluene sulphonic acid, methane sulphonic acid, hydrochloric acid or sulphuric acid.
Claim 11
Dependent Claim
20 words
A process according to claim 9 wherein the concentration of toluene sulphonic acid in the acidic solution is 5-25 gl/l.
Claim 12
Dependent Claim
14 words
A process according to claim 1 wherein the acidic solution further comprises a salt.
Claim 13
Dependent Claim
19 words
A process according to claim 11 wherein the salt is derived from the acidic component of the acidic solution.
Claim 14
Dependent Claim
14 words
A process according to claim 1 wherein the pH of the solution is 1.7-2.5.
Claim 15
Dependent Claim
17 words
A process according to claim 1 wherein the oxidising agent is the permanganate of an alkali metal.
Claim 16
Dependent Claim
14 words
A process according to claim 1 wherein the board is a drilled epoxy laminate.
Claim 17
Dependent Claim
30 words
A process according to claim 1 wherein the board is a double sided 4:1 aspect ratio board, a multi-layer 4:1 aspect ratio board or a high 8:1 aspect ratio board.
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) | 1995-04-21 | 1995-10-21 | 1996-04-21 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1999-04-21 | 1999-10-21 | 2000-04-21 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2003-04-21 | 2003-10-21 | 2004-04-21 | $7700.00 | Window Closed / Lapsed |