US4019877A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Method for coating of polyimide by electrodeposition
Assignee: Westinghouse Electric Corp
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Filing: 1975-10-21
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Granted: 1977-04-26
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Expires: 1995-10-21
Abstract
Abstract A method of coating a copper substrate comprises the steps of: anodically microsmoothing the copper substrate in an acid bath to provide a substantially smooth surface; electrocoating the microsmoothed substrate with a pin hole free nickel film having a thickness of between about 2.5 microns to about 12.5 microns; single step, non-aqueous electrocoating the microsmoothed, nickel coated substrate with a pin hole free polyamic acid polymer, and curing the polyamic acid coating to form a polyimide film free of copper ion contamination.
Inventors
- 👤 William R. Gass
- 👤 Luciano C. Scala
- 👤 David C. Phillips
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-25 17:26
CPC Classifications
C; C25; C25D; C25D13/00; C25D13/20; C09; C09D; C09D5/00; C09D5/44; C09D5/4419; C09D5/4461; H; H05; H05K; H05K3/00; H05K3/02; H05K3/022; Y; Y10; Y10T; Y10T428/00; Y10T428/12; Y10T428/12493; Y10T428/12535; Y10T428/12556; Y10T428/12569; Y10T428/12771; Y10T428/12861; Y10T428/12903; Y10T428/1291
Claims Analysis
Total Claims: 17
Claim 1
Independent Claim
133 words
A method of coating a copper substrate comprising the steps of: A. anodically microsmoothing the copper substrate surface by making the substrate surface a positive electrode in an acid bath at a current density of between 100 amp./sq. ft. to 2,000 amp./sq. ft., said acid being effectively active within the current density range to dissolve copper and to provide a substantially smooth copper surface, B. electrocoating the microsmoothed substrate with a pin hole free nickel film having a thickness of between about 2.5 microns to about 12.5 microns, said film being effective to prevent copper ion diffusion, C. single step, non-aqueous electrocoating the microsmoothed, nickel coated substrate with a pin hole free polyamic acid polymer film, and D. curing the polyamic acid coating to form a polyimide film free of copper ion deposits.
Claim 2
Independent Claim
133 words
A method of coating a copper substrate comprising the steps of: A. anodically microsmoothing the copper substrate surface by making the substrate surface a positive electrode in an acid bath at a current density of between 100 amp./sq. ft. to 2,000 amp./sq. ft., said acid being effectively active within the current density range to dissolve copper and to provide a substantially smooth copper surface, B. electrocoating the microsmoothed substrate with a pin hole free nickel film having a thickness of between about 2.5 microns to about 12.5 microns, said film being effective to prevent copper ion diffusion, C. single step, non-aqueous electrocoating the microsmoothed, nickel coated substrate with a pin hole free polyamic acid polymer film, and D. curing the polyamic acid coating to form a polyimide film free of copper ion deposits.
Claim 3
Dependent Claim
65 words
The method of claim 1 wherein the copper substrate is placed in a nickel containing bath of nickel chloride between steps (A) and (B), made a cathode, and current applied, said current being effective to reduce any oxides present to copper metal and to electrocoat the substrate with a nickel strike film, and the copper substrate is rinsed water between step (B) and step (C).
Claim 4
Dependent Claim
32 words
The method of claim 2, wherein the nickel film is electrocoated in step (B) from a nickel containing bath selected from the group consisting of nickel sulfamate solution and nickel sulfate solution.
Claim 5
Dependent Claim
43 words
The method of claim 3 wherein the nickel strike film electrocoated between step (A) and step (B) from a nickel containing bath of nickel chloride is between about 0.25 micron to about 1.25 microns thick, and the copper substrate is a wound coil.
Claim 6
Dependent Claim
36 words
The method of claim 4 wherein the current density in the nickel electrocoating steps is between about 10 amp./sq. ft. to about 100 amp./sq. ft. and the polyamic acid polymer is electrocoated from a colloidal composition.
Claim 7
Independent Claim
59 words
The method of clam 2 wherein the polyamic acid polymer is electrocoated from a composition comprising a polyamic acid polymer, a nitrogen containing base which reacts with the acid to form a salt, and a dual liquid system consisting of a liquid, organic, non-aqueous solvent for the acid and a liquid, non-aqueous, non-solvent for the salt of the acid.
Claim 8
Independent Claim
59 words
The method of clam 2 wherein the polyamic acid polymer is electrocoated from a composition comprising a polyamic acid polymer, a nitrogen containing base which reacts with the acid to form a salt, and a dual liquid system consisting of a liquid, organic, non-aqueous solvent for the acid and a liquid, non-aqueous, non-solvent for the salt of the acid.
Claim 9
Dependent Claim
35 words
The method of claim 2 wherein the acid in Step (A) is selected from the group consisting of phosphoric acid and sulfuric acid and the copper substrate is rinsed between step (A) and step (B).
Claim 10
Dependent Claim
19 words
The method of claim 1 wherein the copper substrate is cleaned and degreased at least once before step (B).
Claim 11
Independent Claim
279 words
A method of coating the surface of a copper substrate comprising the steps of: A. cleaning the substrate in a degreasing solution and rinsing with water, B. microsmoothing the copper substrate surface by making the surface a positive electrode in an acid bath selected from the group consisting of phosphoric acid and sulfuric acid, said bath having a pH of from about 0.25 to 2.0, at a current density of between 100 amp./sq. ft. to 2,000 amp./sq. ft. to dissolve copper and to provide a substantially smooth copper surface, and rinsing with water, C. placing the copper substrate in a nickel containing bath of nickel chloride, making the substrate a cathode, and applying current effective to reduce any oxides present to copper metal and to electrocoat the substrate with a nickel strike film, D. placing the nickel strike coated copper substrate in a nickel containing bath selected from the group consisting of nickel sulfamate solution and nickel sulfate solution, making the substrate a cathode, and electrocoating the substrate with a pin hole free nickel film having a thickness of between about 2.5 microns to about 12.5 microns, said film being effective to prevent copper ion diffusion, E. single step, non-aqueous electrocoating the microsmoothed, nickel coated substrate with a pin hole free polyamic acid polymer film from a composition comprising a polyamic acid polymer, a nitrogen containing base which reacts with the acid to form a salt, and a dual liquid system consisting of a liquid, organic, non-aqueous solvent for the acid and a liquid, non-aqueous, non-solvent for the salt of the acid, and F. curing the polyamic acid coating to form a polyimide film free of copper ion deposits.
Claim 12
Independent Claim
279 words
A method of coating the surface of a copper substrate comprising the steps of: A. cleaning the substrate in a degreasing solution and rinsing with water, B. microsmoothing the copper substrate surface by making the surface a positive electrode in an acid bath selected from the group consisting of phosphoric acid and sulfuric acid, said bath having a pH of from about 0.25 to 2.0, at a current density of between 100 amp./sq. ft. to 2,000 amp./sq. ft. to dissolve copper and to provide a substantially smooth copper surface, and rinsing with water, C. placing the copper substrate in a nickel containing bath of nickel chloride, making the substrate a cathode, and applying current effective to reduce any oxides present to copper metal and to electrocoat the substrate with a nickel strike film, D. placing the nickel strike coated copper substrate in a nickel containing bath selected from the group consisting of nickel sulfamate solution and nickel sulfate solution, making the substrate a cathode, and electrocoating the substrate with a pin hole free nickel film having a thickness of between about 2.5 microns to about 12.5 microns, said film being effective to prevent copper ion diffusion, E. single step, non-aqueous electrocoating the microsmoothed, nickel coated substrate with a pin hole free polyamic acid polymer film from a composition comprising a polyamic acid polymer, a nitrogen containing base which reacts with the acid to form a salt, and a dual liquid system consisting of a liquid, organic, non-aqueous solvent for the acid and a liquid, non-aqueous, non-solvent for the salt of the acid, and F. curing the polyamic acid coating to form a polyimide film free of copper ion deposits.
Claim 13
Dependent Claim
48 words
The method of claim 9 wherein the nickel film is electrocoated at a current density of between about 10 amp./sq. ft. to about 1,000 amp./sq. ft. in step (C) and at a current density of between about 10 amp./sq. ft. to about 100 amp./sq. ft. in step (D).
Claim 14
Dependent Claim
13 words
The method of claim 9 wherein the copper substrate is a wound coil.
Claim 15
Dependent Claim
12 words
The method of claim 9 wherein the copper substrate is a wire.
Claim 16
Dependent Claim
12 words
The method of claim 9 wherein the copper substrate is a foil.
Claim 17
Dependent Claim
11 words
A wound copper coil coated by the method of claim 9.
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) | 1980-04-25 | 1980-10-25 | 1981-04-26 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1984-04-25 | 1984-10-25 | 1985-04-26 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1988-04-25 | 1988-10-25 | 1989-04-26 | $7700.00 | Window Closed / Lapsed |