US4969979A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Direct electroplating of through holes
Assignee: International Business Machines Corp
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Filing: 1989-05-08
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Granted: 1990-11-13
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Expires: 2009-05-08
Abstract
Abstract Substantially nonconductive or semiconductive surfaces of through holes can be electroplated directly, without an intervening non-electrolytic metallization, by a stepwise process which includes the application to the through holes of a polyelectrolyte surfactant in solution in combination with the application of a conductive metal containing material.
Inventors
- 👤 Bernd K. Appelt
- 👤 Perminder Bindra
- 👤 Robert D. Edwards
- 👤 James R. Loomis
- 👤 Jae M. Park
- 👤 Jonathan D. Reid
- 👤 Lisa J. Smith
- 👤 James R. White
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-06 18:08
CPC Classifications
C; C25; C25D; C25D5/00; C25D5/54; C25D5/56; H; H05; H05K; H05K3/00; H05K3/40; H05K3/42; H05K3/423; H05K3/424; H05K2203/00; H05K2203/07; H05K2203/0703; H05K2203/0716; H05K2203/12; H05K2203/122; H05K3/425; H05K3/427
Claims Analysis
Total Claims: 20
Claim 1
Independent Claim
148 words
A method for the direct electroplating of the walls within a through hole in a metal clad dielectric laminate, without an electroless plating step, the method comprising the steps of: providing at least one through hole in the metal clad laminate; cleaning away any drill smear; applying a solution of surfactant to the walls of the through hole; rinsing away any surfactant in excess of an amount useful to attract and promote adhesion of a metal-containing material to the wall of the through hole; applying a solution comprising metal containing material to the wall of the through hole; rinsing away any excess conductive metal-containing material from the hole so as to leave a quantity of the material in the walls sufficient to permit electroplating; and electroplating metal to a predetermined thickness on the wall of the through hole which has been rendered conductive by the metal containing material.
Claim 2
Independent Claim
148 words
A method for the direct electroplating of the walls within a through hole in a metal clad dielectric laminate, without an electroless plating step, the method comprising the steps of: providing at least one through hole in the metal clad laminate; cleaning away any drill smear; applying a solution of surfactant to the walls of the through hole; rinsing away any surfactant in excess of an amount useful to attract and promote adhesion of a metal-containing material to the wall of the through hole; applying a solution comprising metal containing material to the wall of the through hole; rinsing away any excess conductive metal-containing material from the hole so as to leave a quantity of the material in the walls sufficient to permit electroplating; and electroplating metal to a predetermined thickness on the wall of the through hole which has been rendered conductive by the metal containing material.
Claim 3
Dependent Claim
13 words
The method as recited in claim 1 wherein the electroplated metal comprises copper.
Claim 4
Dependent Claim
12 words
The method recited in claim 1 wherein the surfactant comprises a polyelectrolyte.
Claim 5
Dependent Claim
15 words
The method recited in claim 3 wherein the metal containing material comprises a conductive colloid.
Claim 6
Dependent Claim
13 words
The method recited in claim 3 wherein the polyelectrolyte comprises a cationic polyelectrolyte.
Claim 7
Dependent Claim
14 words
The method recited in claim 3 wherein the polyelectrolyte comprises an acrylic acid backbone.
Claim 8
Dependent Claim
13 words
The method recited in claim 3 wherein the polyelectrolyte comprises a anionic polyelectrolyte.
Claim 9
Dependent Claim
14 words
The method recited in claim 3 wherein the polyelectrolyte comprises a sulfonic acid group.
Claim 10
Dependent Claim
13 words
The method recited in claim 3 wherein the polyelectrolyte comprises an amine group.
Claim 11
Dependent Claim
42 words
The method recited in claim 3 wherein the type of metal containing material comprises ruthenium III chloride converted to ruthenium IV oxide, the method including also the steps of rinsing in solution comprising alkaline earth hydroxide and water rinsing prior to electroplating.
Claim 12
Dependent Claim
48 words
The method recited in claim 3 wherein the metal containing material comprises a soluble salt of a conductive metal in solution, the method including the additional step just prior to the electroplating step of rinsing the walls of the through holes in a solution comprising a reducing agent.
Claim 13
Dependent Claim
16 words
The method recited in claim 4 wherein the Sn/Pd colloid solution also includes carbon black particles.
Claim 14
Dependent Claim
13 words
The method recited in claim 4 wherein the conductive colloid comprises Sn/Pd colloid.
Claim 15
Dependent Claim
13 words
The method recited in claim 4 wherein the conductive colloid comprises copper colloid.
Claim 16
Dependent Claim
17 words
The method recited in claim 5 wherein the polyelectrolyte comprises a copolymer of acrylamide and beta-methacryl-oxyethyltrimethylamnonium-methyl sulfate.
Claim 17
Dependent Claim
24 words
The method recited in claim 13 comprising the additional step of applying to the walls of the through holes a microetch solution containing persulfate.
Claim 18
Dependent Claim
25 words
The method recited in claim 13 comprising the additional step of drying the sidewall of the through hole after the application of the Sn/Pd colloid
Claim 19
Dependent Claim
144 words
A printed circuit board defining at least one conductive through hole therein formed by the process comprising the steps of: providing at least one through hole within the metal clad laminate; cleaning away any drill smear; applying a solution of polyelectrolyte to the walls of the through hole; rinsing away any polyelectrolyte in excess of an amount useful to attract and promote adhesion of a metal-containing material to the wall of the through hole; applying a solution comprising metal containing material not including an electroless plating bath to the wall of the through hole; rinsing away any excess conductive metal-containing material from the hole so as to leave a quantity of the material in the walls sufficient to permit electroplating; and electroplating metal to a predetermined thickness on the wall of the through hole which has been rendered conductive by the metal containing material.
Claim 20
Dependent Claim
144 words
A printed circuit board defining at least one conductive through hole therein formed by the process comprising the steps of: providing at least one through hole within the metal clad laminate; cleaning away any drill smear; applying a solution of polyelectrolyte to the walls of the through hole; rinsing away any polyelectrolyte in excess of an amount useful to attract and promote adhesion of a metal-containing material to the wall of the through hole; applying a solution comprising metal containing material not including an electroless plating bath to the wall of the through hole; rinsing away any excess conductive metal-containing material from the hole so as to leave a quantity of the material in the walls sufficient to permit electroplating; and electroplating metal to a predetermined thickness on the wall of the through hole which has been rendered conductive by the metal containing material.
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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) | 1993-11-12 | 1994-05-14 | 1994-11-13 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1997-11-12 | 1998-05-14 | 1998-11-13 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2001-11-12 | 2002-05-14 | 2002-11-13 | $7700.00 | Window Closed / Lapsed |