US5213840A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Method for improving adhesion to polymide surfaces
Assignee: MacDermid Acumen Inc
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Filing: 1991-06-10
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Granted: 1993-05-25
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Expires: 2011-06-10
Abstract
Abstract The adhesion between surfaces of polyimide, particularly the through hole surfaces of polyimide-based multilayer laminates used in the fabrication of multilayer printed circuits, is improved by pretreatment of the surfaces with an essentially non-alkaline aqueous permanganate solution.
Inventors
- 👤 Richard C. Retallick
- 👤 Raymond A. Letize
- 👤 Peter E. Kukanskis
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-09 13:26
CPC Classifications
H; H05; H05K; H05K3/00; H05K3/38; H05K3/381; C; C23; C23C; C23C18/00; C23C18/16; C23C18/18; C23C18/20; C23C18/22; H05K3/0011; H05K3/0055; H05K2201/00; H05K2201/01; H05K2201/0137; H05K2201/0154; H05K2203/00; H05K2203/07; H05K2203/0779; H05K2203/0786; H05K2203/0796
Claims Analysis
Total Claims: 17
Claim 1
Independent Claim
127 words
In a process for preparing for electroless metallization the surfaces of through holes formed in a multilayer laminate comprised of alternating layers of conductive circuitry and insulating substrate material, and wherein said insulating substrate material is comprised of a polyimide, in which process the surfaces of said through holes are subjected to a desmearing and/or etchback treatment prior to electroless deposition, the improvement comprising contacting said through holes, after and separate from said desmearing and/or etch back treatment and prior to electroless metallization, with an aqueous permanganate solution having a pH of about 8 or less, for a time and at conditions effective to render the through holes more receptive to adherent receipt of subsequently-applied electroless metal, and thereafter neutralizing manganese residue on said through hole surfaces.
Claim 2
Dependent Claim
127 words
In a process for preparing for electroless metallization the surfaces of through holes formed in a multilayer laminate comprised of alternating layers of conductive circuitry and insulating substrate material, and wherein said insulating substrate material is comprised of a polyimide, in which process the surfaces of said through holes are subjected to a desmearing and/or etchback treatment prior to electroless deposition, the improvement comprising contacting said through holes, after and separate from said desmearing and/or etch back treatment and prior to electroless metallization, with an aqueous permanganate solution having a pH of about 8 or less, for a time and at conditions effective to render the through holes more receptive to adherent receipt of subsequently-applied electroless metal, and thereafter neutralizing manganese residue on said through hole surfaces.
Claim 3
Dependent Claim
24 words
A process according to claim 1 wherein said aqueous permanganate solution has a pH in the range of from about 4 to about 8.
Claim 4
Dependent Claim
23 words
A process according to claim 2 wherein said aqueous permanganate solution has a pH in the range of from about 6 to 8.
Claim 5
Dependent Claim
21 words
A process according to claim 1 wherein said aqueous permanganate solution contains from about 20 to about 150 g/l of permanganate.
Claim 6
Dependent Claim
28 words
A process according to claim 4 wherein said contacting with said aqueous permanganate solution is at a solution temperature of from about 100° F. to about 200° F.
Claim 7
Dependent Claim
14 words
A process according to claim 1 wherein said insulating substrate material comprises glass-reinforced polyimide.
Claim 8
Dependent Claim
15 words
A process according to claim 1 wherein said insulating substrate material comprises glass-reinforced polyimide/epoxy co-polymer.
Claim 9
Dependent Claim
15 words
A process according to claim 1 wherein said desmearing and/or etch back comprises plasma desmearing.
Claim 10
Dependent Claim
31 words
A process according to claim 1 wherein said desmearing and/or etch back comprises contact of said through hole surfaces with an aqueous permanganate solution having a pH of at least 13.
Claim 11
Dependent Claim
124 words
A process for metallizing the through hole surfaces of a multilayer printed circuit laminate comprised of alternating layers of conductive circuitry and insulating substrate material comprised of polyimide, said process comprising the steps of: (a) treating said through hole surfaces to remove resin smear from exposed edges of conductive circuitry at the through hole surfaces and/or to etch back said insulating substrate material at the through hole surfaces; (b) thereafter contacting said through hole surfaces, in a step separate from said desmearing and/or etch back treatment, with an aqueous permanganate solution having a pH of about 8 or less; (c) thereafter neutralizing manganese residues on said through hole surfaces; and (d) thereafter electrolessly metallizing said through hole surfaces using an electroless copper plating bath.
Claim 12
Dependent Claim
124 words
A process for metallizing the through hole surfaces of a multilayer printed circuit laminate comprised of alternating layers of conductive circuitry and insulating substrate material comprised of polyimide, said process comprising the steps of: (a) treating said through hole surfaces to remove resin smear from exposed edges of conductive circuitry at the through hole surfaces and/or to etch back said insulating substrate material at the through hole surfaces; (b) thereafter contacting said through hole surfaces, in a step separate from said desmearing and/or etch back treatment, with an aqueous permanganate solution having a pH of about 8 or less; (c) thereafter neutralizing manganese residues on said through hole surfaces; and (d) thereafter electrolessly metallizing said through hole surfaces using an electroless copper plating bath.
Claim 13
Dependent Claim
24 words
A process according to claim 10 wherein said treatment of step (a) comprises contact of said through hole surfaces with an aqueous caustic solution.
Claim 14
Dependent Claim
21 words
A process according to claim 10 wherein said treatment of step (a) comprises subjecting said through hole surfaces to plasma desmearing.
Claim 15
Dependent Claim
31 words
A process according to claim 10 wherein said treatment of step (a) comprises contacting said through hole surfaces with an aqueous solution of permanganate having a pH of at least 13.
Claim 16
Dependent Claim
26 words
A process according to claim 10 wherein said electroless copper plating bath comprises a hypophosphite-reduced electroless copper plating bath having a pH of 10 or less.
Claim 17
Dependent Claim
23 words
A process according to claim 10 wherein, subsequent to step (d), said through hole surfaces are provided with a layer of electroplated copper.
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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) | 1996-05-24 | 1996-11-23 | 1997-05-25 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 2000-05-24 | 2000-11-23 | 2001-05-25 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2004-05-24 | 2004-11-23 | 2005-05-25 | $7700.00 | Window Closed / Lapsed |