Patent US5213840A successfully refreshed from Google Patents.
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 14:13
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.
References Cited (Backward Citations)
GB1479556A
Cited
US4287253A
Cited
JPS5388960A
Cited
US4209331A
Cited
US4279948A
Cited
JPS559459A
Cited
US4576689A
Cited
US4374868A
Cited
US4863758A
Cited
US4425380A
Cited
US4597988A
Cited
US4756930A
Cited
US4515829A
Cited
WO1985005755A1
Cited
US4592852A
Cited
US4629636A
Cited
US4820548A
Cited
US4668532A
Cited
US4873122A
Cited
US4751106A
Cited
EP0267452A2
Cited
US4832799A
Cited
US4725504A
Cited
US4842946A
Cited
US4800461A
Cited
US4895739A
Cited
US4874635A
Cited
WO1989010431A1
Cited
US4873136A
Cited
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 |