Patent US4931148A successfully refreshed from Google Patents.
US4931148A
Expired / Lapsed
US
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Method for manufacture of printed circuit boards
Assignee: MacDermid Acumen Inc
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Filing: 1988-09-27
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Granted: 1990-06-05
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Expires: 2008-09-27
Abstract
Abstract Printed circuit boards containing thru-holes requiring metallization are manufactured by first applying to the board material an alkaline strippable resist in a predetermined desired pattern, thereafter applying material catalytic to subsequent metallization, thereafter treating the board with an aqueous alkaline solution to remove catalytic material from resist surfaces without adversely affecting the catalyst at non-resist areas, and then metallizing the non-resist areas. The ability to preliminarily apply the resist pattern before catalyst application, metallization, etc., yet prevent metallization of the resist, enables the manufacturing process to proceed straight through the activation, metallization, etc. steps without need for interruption for resist application.
Inventors
- 👤 Peter E. Kukanskis
- 👤 Harold Rhodenizer
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-05 18:52
CPC Classifications
C; C25; C25D; C25D5/00; C25D5/54; C25D5/56; H; H05; H05K; H05K3/00; H05K3/10; H05K3/108; H05K3/18; H05K3/181; H05K3/182; H05K3/184; H05K3/40; H05K3/42; H05K3/425; H05K3/427; H05K2203/00; H05K2203/07; H05K2203/0703; H05K2203/0706; H05K2203/072; H05K2203/0756; H05K2203/0769; H05K2203/0779; H05K2203/0786; H05K2203/0793; H05K2203/14; H05K2203/1415; H05K2203/1476; H05K3/02; H05K3/06; H05K3/061; H05K3/062; Y; Y10; Y10S; Y10S205/00; Y10S205/924; Y10S205/926
Claims Analysis
Total Claims: 10
Claim 1
Independent Claim
296 words
A method for metallizing thru-holes formed in a metal-clad printed circuit board substrate material and for providing at the same time additional metallization of selected metal-clad surfaces of said metal-clad printed circuit board substrate material, comprising the steps of: (a) providing a metal-clad printed circuit board substrate material having one or more thru-holes therein; (b) applying a resist which is strippable in aqueous alkaline medium to selected surfaces of said metal-clad printed circuit board substrate material in a predetermined pattern to define those surfaces areas, over which resist is applied, where additional metallization is not desired; (c) thereafter contacting said metal-clad printed circuit board substrate material, having said patterned resist thereon, with a conditioner; (d) thereafter contacting said conditioned metal-clad printed circuit board substrate material, having said patterned resist thereon, with a microetchant; (e) thereafter contacting said conditioned and micro-etched metal-clad printed circuit board substrate material, having said patterned resist thereon, with catalytic species which promote metallization, resulting in the provision of said catalytic species on thru-hole surfaces, resist surfaces and the surfaces of said metal-clad printed circuit board substrate material not covered by said resist; (f) thereafter contacting at least said resist surfaces of said metal-clad printed circuit board substrate material with an aqueous alkaline deactivating solution under conditions which substantially inactivate said resist surfaces to metallization without substantially removing the resist surfaces and without inactivating said thru-hole surfaces and the surfaces of said metal-clad printed circuit board substrate material not covered by said resist; and (g) thereafter immersing said metal-clad printed circuit board substrate material, having said patterned resist thereon, in a metallizing solution effective to metallize said thru-hole surfaces and the surfaces of said metal-clad printed circuit board material not covered by said result, with substantially no metallization occurring on said resist surfaces.
Claim 2
Independent Claim
296 words
A method for metallizing thru-holes formed in a metal-clad printed circuit board substrate material and for providing at the same time additional metallization of selected metal-clad surfaces of said metal-clad printed circuit board substrate material, comprising the steps of: (a) providing a metal-clad printed circuit board substrate material having one or more thru-holes therein; (b) applying a resist which is strippable in aqueous alkaline medium to selected surfaces of said metal-clad printed circuit board substrate material in a predetermined pattern to define those surfaces areas, over which resist is applied, where additional metallization is not desired; (c) thereafter contacting said metal-clad printed circuit board substrate material, having said patterned resist thereon, with a conditioner; (d) thereafter contacting said conditioned metal-clad printed circuit board substrate material, having said patterned resist thereon, with a microetchant; (e) thereafter contacting said conditioned and micro-etched metal-clad printed circuit board substrate material, having said patterned resist thereon, with catalytic species which promote metallization, resulting in the provision of said catalytic species on thru-hole surfaces, resist surfaces and the surfaces of said metal-clad printed circuit board substrate material not covered by said resist; (f) thereafter contacting at least said resist surfaces of said metal-clad printed circuit board substrate material with an aqueous alkaline deactivating solution under conditions which substantially inactivate said resist surfaces to metallization without substantially removing the resist surfaces and without inactivating said thru-hole surfaces and the surfaces of said metal-clad printed circuit board substrate material not covered by said resist; and (g) thereafter immersing said metal-clad printed circuit board substrate material, having said patterned resist thereon, in a metallizing solution effective to metallize said thru-hole surfaces and the surfaces of said metal-clad printed circuit board material not covered by said result, with substantially no metallization occurring on said resist surfaces.
Claim 3
Dependent Claim
19 words
The method according to claim 1 wherein said metallizing solution of step (g) is an electroless metal depositing solution.
Claim 4
Dependent Claim
58 words
The method according to claim 2 further comprising, subsequent to step (g), building up additional metal coating on the surfaces metallized in step (g) by immersing said metal-clad printed circuit board substrate material, having said pattern resist thereon, in a metal electroplating solution effective to deposit additional metal over said metallized areas but not on said resist surfaces.
Claim 5
Dependent Claim
18 words
The method according to claim 1 wherein said metallization solution of step (g) is a metal electroplating solution.
Claim 6
Dependent Claim
25 words
The method according to claim 1 wherein said aqueous alkaline deactivating solution has a pH in the range of from about 8.0 to about 11.5.
Claim 7
Dependent Claim
32 words
The method according to claim 5 wherein said aqueous alkaline deactivating solution is an aqueous solution of an alkaline material selected from the group consisting of hydroxides, carbonates, borates, and mixtures thereof.
Claim 8
Dependent Claim
36 words
The method according to claim 1 wherein said metal-clad printed circuit board substrate material is a multi-layer printed circuit board substrate material comprised of one or more metal innerlayer planes separated by planes of insulating material.
Claim 9
Dependent Claim
16 words
The method according to claim 1 wherein said metal-clad printed circuit board substrate material is copper-clad.
Claim 10
Dependent Claim
35 words
The method according to claim 8 wherein said metallizing solution is effective to deposit copper metal on said thru-hole surfaces and the surfaces of said metal-clad printed circuit board substrate material not covered by resist.
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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) | 1993-06-04 | 1993-12-04 | 1994-06-05 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1997-06-04 | 1997-12-04 | 1998-06-05 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2001-06-04 | 2001-12-04 | 2002-06-05 | $7700.00 | Window Closed / Lapsed |