US4873136A
Expired / Lapsed
US
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Method for preparing polymer surfaces for subsequent plating thereon, and improved metal-plated plastic articles made therefrom
Assignee: General Electric Co
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Filing: 1988-06-16
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Granted: 1989-10-10
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Expires: 2008-06-16
Abstract
Abstract An improved method for pretreating a polyimide surface in preparation for an adhesion promotion treatment and subsequent metallization is disclosed, wherein the pretreatment comprises mild etching of the surface, contact of the surface with a basic solution, and contact of the surface with a cationic surfactant which is capable of removing a residual film formed on the surface after the mild etching step. This invention further includes articles such as printed circuit boards, which comprise a polyimide substrate pretreated as described above and then treated with an adhesion promoter, wherein an electrolessly-applied metal layer is disposed on the substrate, and an electrolytically-applied metal layer free of chemical additives is disposed on the electrolessly-applied layer. The article may include an additional electrolytically-applied layer containing chemical additives and disposed on top of the first electrolytic layer.
Inventors
- 👤 Donald F. Foust
- 👤 Edward J. Lamby
- 👤 Bradley R. Karas
- 👤 William V. Dumas
- 👤 Elihu C. Jerabek
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-25 20:07
CPC Classifications
H; H05; H05K; H05K3/00; H05K3/38; H05K3/381; C; C23; C23C; C23C18/00; C23C18/16; C23C18/18; C23C18/20; C23C18/22; H05K3/10; H05K3/18; H05K3/181; Y; Y10; Y10S; Y10S205/00; Y10S205/924; Y10S205/926; Y10S428/00; Y10S428/901; Y10T; Y10T428/00; Y10T428/12; Y10T428/12389; Y10T428/12396; Y10T428/12493; Y10T428/12535; Y10T428/12556; Y10T428/12569; Y10T428/24; Y10T428/24802; Y10T428/24917; Y10T428/31504; Y10T428/31678; Y10T428/31681; Y10T428/31725
Claims Analysis
Total Claims: 36
Claim 1
Independent Claim
60 words
A method for pretreating a polyimide surface in preparation for an adhesion promotion treatment and subsequent metallization on the surface, comprising mild etching of the surface, contact of the surface with a basic solution, and contact of the surface with a cationic surfactant which is capable of removing a residual film formed on the surface after the mild etching step.
Claim 2
Independent Claim
60 words
A method for pretreating a polyimide surface in preparation for an adhesion promotion treatment and subsequent metallization on the surface, comprising mild etching of the surface, contact of the surface with a basic solution, and contact of the surface with a cationic surfactant which is capable of removing a residual film formed on the surface after the mild etching step.
Claim 3
Dependent Claim
32 words
The method of claim 1 wherein the mild etching step is performed by contact with a compound selected from the group consisting of sulfuric acid, N,N-dimethylformamide, N-methyl-2-pyrrolidone, pyridine, tetrahydrofuran, and methylene chloride.
Claim 4
Dependent Claim
25 words
The method of claim 2 wherein the etching compound is sulfuric acid dissolved in water at a concentration of at least about 85% by weight.
Claim 5
Dependent Claim
22 words
The method of claim 2 wherein the surface is cleaned by contact with a halocarbon material prior to the mild etching step.
Claim 6
Dependent Claim
29 words
The method of claim 1 wherein the basic solution comprises water and a compound selected from the group consisting of sodium hydroxide, potassium hydroxide, tetramethylammonium hydroxide, and mixtures thereof.
Claim 7
Dependent Claim
22 words
The method of claim 5 wherein the concentration of the basic compound in water is about 0.1 molar to about 10 molar.
Claim 8
Dependent Claim
30 words
The method of claim 6 wherein the cationic surfactant is used in the form of an aqueous solution at a concentration of from about 3×10 -4 M to about 0.3M.
Claim 9
Dependent Claim
18 words
The method of claim 7 wherein the concentration of cationic surfactant ranges from about 0.001M to about 0.1M.
Claim 10
Dependent Claim
13 words
The method of claim 7 wherein the aqueous solution also contains a defoamer.
Claim 11
Dependent Claim
22 words
The method of claim 7 wherein the aqueous solution is used at a temperature in the range of about 20° C.-60° C.
Claim 12
Dependent Claim
11 words
The method of claim 1 wherein the cationic surfactant is water-soluble.
Claim 13
Dependent Claim
12 words
The method of claim 11 wherein the cationic surfactant is stearyldimethylbenzylammonium bromide.
Claim 14
Dependent Claim
25 words
The method of claim 11 wherein the cationic surfactant is selected from the group consisting of alkylpyridinium halides, alkyltrimethylammonium halides, alkyltriphenylphosphonium halides, and tetraalkylammonium halides.
Claim 15
Dependent Claim
27 words
The method of claim 13 wherein the cationic surfactant is selected from the group consisting of cetylpyridinium bromide monohydrate, cetylpyridinium chloride monohydrate, dodecyltrimethylammonium bromide, and hexadecyltrimethylammonium bromide.
Claim 16
Dependent Claim
33 words
The method of claim 13 wherein the cationic surfactant is selected from the group consisting of dodecylpyridinium chloride, octyltrimethylammonium bromide, decyltrimethylammonium bromide, dodecyltrimethylammonium bromide, hexadecyltrimethylammonium bromide, decyltriphenylphosphonium bromide, dodecyltriphenylphosphonium bromide, and tetrabutylammonium chloride.
Claim 17
Dependent Claim
24 words
The method of claim 1 wherein contact of the surface with the basic solution and with the cationic surfactant are performed as one step.
Claim 18
Independent Claim
96 words
A method for the application of a metal layer onto a polyimide surface, comprising a pretreatment of the surface by mild etching, contact of the surface with a basic solution, and contact of the surface with a cationic surfactant which is capable of removing a residual film formed on the surface after the mild etching step, followed by treatment of the surface with an adhesion promoter selected from the group consisting of compounds characterized by the presence of an >NO-- moiety and compounds containing an organic double bond, followed by the electroless deposition of the metal.
Claim 19
Independent Claim
96 words
A method for the application of a metal layer onto a polyimide surface, comprising a pretreatment of the surface by mild etching, contact of the surface with a basic solution, and contact of the surface with a cationic surfactant which is capable of removing a residual film formed on the surface after the mild etching step, followed by treatment of the surface with an adhesion promoter selected from the group consisting of compounds characterized by the presence of an >NO-- moiety and compounds containing an organic double bond, followed by the electroless deposition of the metal.
Claim 20
Dependent Claim
45 words
The method of claim 17 wherein the adhesion promoting compound is selected from the group consisting of hydroxylamine, salts of hydroxylamine, O,N-dimethylhydroxylamine hydrochloride, acetone oxime, 2-pyridine aldoxime, N-hydroxyphthalimide, 1-hydroxybenzotriazole·H 2 O, thiosemicarbazide hydrochloride, 2,4-dithiobiuret, semicarbazide hydrochloride, acetylthiourea, thiourea, acetamide, urea, N,N-dimethylacetamide, thioacetamide, and thiocyanuric acid.
Claim 21
Dependent Claim
32 words
The method of claim 18 wherein the mild etching step is performed by contact with a compound selected from the group consisting of sulfuric acid, N,N-dimethylformamide, N-methyl-2-pyrrolidone, pyridine, tetrahydrofuran, and methylene chloride.
Claim 22
Dependent Claim
29 words
The method of claim 19 wherein the basic solution comprises water and a compound selected from the group consisting of sodium hydroxide, potassium hydroxide, tetramethylammonium hydroxide, and mixtures thereof.
Claim 23
Dependent Claim
47 words
The method of claim 20 wherein the long-chain cationic surfactant is selected from the group consisting of cetylpyridinium chloride monohydrate, dodecyltrimethylammonium bromide, and hexadecyltrimethylammonium bromide, and is used in the form of an aqueous solution at a concentration of from about 3×10 -4 M to about 0.3M.
Claim 24
Dependent Claim
25 words
The method of claim 17 wherein a layer of metal which is free of chemical additives is electrolytically deposited on top of the electrolessly-applied layer.
Claim 25
Dependent Claim
26 words
The method of claim 22 wherein a metal layer which contains effective amounts of chemical additives is electrolytically deposited on top of the first electrolytically-deposited layer.
Claim 26
Dependent Claim
14 words
The method of claim 23 wherein the chemical additives comprise leveling agents and brighteners.
Claim 27
Dependent Claim
13 words
The method of claim 23 wherein each metallization layer is formed of copper.
Claim 28
Dependent Claim
20 words
The method of claim 25 wherein the metal on the polyimide surface is patterned to form a printed circuit pathway.
Claim 29
Dependent Claim
84 words
An article comprising (A) a polyimide substrate which has been pretreated by mild etching of the surface, contact of the surface with a basic solution, and contact of the surface with a cationic surfactant which is capable of removing a residual film formed on the surface after the mild etching step, followed by treatment with an adhesion-promoting compound; (B) an electrolessly-applied metal layer disposed on the substrate; and (C) an electrolytically-applied metal layer free of chemical additives disposed on top of the electrolessly-applied layer.
Claim 30
Dependent Claim
84 words
An article comprising (A) a polyimide substrate which has been pretreated by mild etching of the surface, contact of the surface with a basic solution, and contact of the surface with a cationic surfactant which is capable of removing a residual film formed on the surface after the mild etching step, followed by treatment with an adhesion-promoting compound; (B) an electrolessly-applied metal layer disposed on the substrate; and (C) an electrolytically-applied metal layer free of chemical additives disposed on top of the electrolessly-applied layer.
Claim 31
Dependent Claim
21 words
The article of claim 27 further including a second electrolytically-applied layer disposed on the first electrolytically-applied layer and containing chemical additives.
Claim 32
Dependent Claim
13 words
The article of claim 28 wherein each metal layer is formed of copper.
Claim 33
Dependent Claim
48 words
The article of claim 28 wherein the electrolessly-applied layer has a thickness of from about 0.2 micron to about 2 microns; the first electrolytically-applied layer has a thickness of at least about 5 microns; and the second electrolytically-applied layer has a thickness of at least about 5 microns.
Claim 34
Dependent Claim
55 words
A printed circuit board comprising: (A) a polyimide substrate; (B) an electrolessly-applied metal layer disposed on the substrate; and (C) an electrolytically-applied metal layer free of chemical additives disposed on top of the electrolessly-applied layer; wherein the metal layers are a pattern of traces which provide electrical connections between components on the printed circuit board.
Claim 35
Dependent Claim
55 words
A printed circuit board comprising: (A) a polyimide substrate; (B) an electrolessly-applied metal layer disposed on the substrate; and (C) an electrolytically-applied metal layer free of chemical additives disposed on top of the electrolessly-applied layer; wherein the metal layers are a pattern of traces which provide electrical connections between components on the printed circuit board.
Claim 36
Dependent Claim
29 words
The printed circuit board of claim 31 wherein a second electrolytically-applied metal layer containing chemical additives is disposed on the first electrolytically-applied layer, and is also a patterned trace.
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) | 1992-10-09 | 1993-04-10 | 1993-10-10 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1996-10-09 | 1997-04-10 | 1997-10-10 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2000-10-09 | 2001-04-10 | 2001-10-10 | $7700.00 | Window Closed / Lapsed |