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US5288519A Expired / Lapsed US ⏱️ 0.0 years remaining

Method of producing modified polyimide layer having improved adhesion to metal layer thereon

Assignee: General Electric Co
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Filing: 1992-04-27
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Granted: 1994-02-22
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Expires: 2012-04-27
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Abstract

Abstract Method of producing a modified polyimide layer to improve adhesion of a metal layer thereon. A limited quantity of water is added to a halogenated polyamic acid to form a reaction product, which is then sprayed, degreased, oxidized and cured into a modified polyimide layer. The chemically modified surface by the aforementioned method is then electrolessly plated with a primary metal layer followed by one or more electrolessly or electrolytically applied secondary metal layers until the metal layer of a desired thickness is attained. The present invention further discloses articles such as an EMI shielded enclosure and an insulated mold surface, having metal layers as an EMI shield and an insulating surface, respectively.

Inventors

  • 👤 Charles E. Baumgartner
  • 👤 Lisa R. Scott

Bibliographic Details

Application Number —
Jurisdiction US
Data Source google_patents
Last Synchronized 2026-11-03 21:54
CPC Classifications
C; C09; C09J; C09J179/00; C09J179/04; C09J179/08; C23; C23C; C23C18/00; C23C18/16; C23C18/18; C23C18/20; C23C18/2006; C23C18/2046; C23C18/2073; C23C18/208; C23C18/28; C23C18/285; C23C18/30; H; H05; H05K; H05K1/00; H05K1/02; H05K1/03; H05K1/0313; H05K1/032; H05K1/0346; H05K3/00; H05K3/10; H05K3/18; H05K3/181; H05K3/38

Claims Analysis

Total Claims: 25
Claim 1
Independent Claim 92 words
A method of improving adhesion of a metal layer on a halogenated polyimide surface comprising: reacting a halogenated polyamic acid with about 0.1 to about 14.0% by weight of added water to form a reaction product; applying a coating of said reaction product over the surface of a substrate about 5 minutes to about 8 hours after adding said water; curing said reaction product coating into a layer of said halogenated polyimide; treating said surface of said polyimide layer with a degreasing agent; and treating said degreased surface with an oxidizing agent.
Claim 2
Independent Claim 92 words
A method of improving adhesion of a metal layer on a halogenated polyimide surface comprising: reacting a halogenated polyamic acid with about 0.1 to about 14.0% by weight of added water to form a reaction product; applying a coating of said reaction product over the surface of a substrate about 5 minutes to about 8 hours after adding said water; curing said reaction product coating into a layer of said halogenated polyimide; treating said surface of said polyimide layer with a degreasing agent; and treating said degreased surface with an oxidizing agent.
Claim 3
Dependent Claim 26 words
The method according to claim 1 wherein said reaction product layer is cured at about 205° C. to 250° C. for about 2 to 8 hours.
Claim 4
Dependent Claim 30 words
The method according to claim 2 wherein said curing step further comprises post-curing said reaction product layer at about 260° C. to 357° C. for about 1 to 24 hours.
Claim 5
Dependent Claim 31 words
The method according to claim 3 wherein temperature of said reaction product layer is ramped up from said cure temperature to said post-cure temperature in about 20 to about 40 minutes.
Claim 6
Dependent Claim 37 words
The method of claim 1 further comprising contacting said surface after said oxidation step with a mild reducing agent for a time sufficient to remove most of the oxidized residue produced during said oxidation of said surface.
Claim 7
Dependent Claim 38 words
The method of claim 5 wherein said reducing agent comprises an aqueous solution of stannous chloride and hydrochloric acid, of hydrogen peroxide and sulfuric acid or ammonium hydroxide, of sodium bisulfite and sulfuric acid, or of hydroxylamine hydrochloride.
Claim 8
Dependent Claim 50 words
The method of claim 1 wherein said oxidizing agent comprises an aqueous solution of alkali metal permanganate and alkali metal hydroxide, of alkali metal dichromate and sulfuric acid, of ammonium dichromate and sulfuric acid, of cerium bisulfate and sulfuric acid, of chromium trioxide and sulfuric acid, or of hydrogen peroxide.
Claim 9
Dependent Claim 45 words
The method of claim 1 wherein said halogenated polyamic acid comprises the following structure: ##STR5## where R' is a halogenated alkyl group, A is a substituted or unsubstituted phenylene or diphenyl ether group, and R is an organic group of 5 to 50 carbon atoms.
Claim 10
Dependent Claim 31 words
The method of claim 8 wherein said organic group is selected from the group consisting of an unsubstituted aliphatic, halogen substituted aliphatic, alicyclic, aromatic, heteroaliphatic, heteroalicyclic, heteroaromatic radical and combinations thereof.
Claim 11
Dependent Claim 14 words
The method of claim 8 wherein R is a benzene or fused polynuclear ring.
Claim 12
Dependent Claim 12 words
The method of claim 8 wherein said halogenated alkyl group is fluorinated.
Claim 13
Dependent Claim 34 words
The method of claim 1 wherein said halogenated polyamic acid comprises the following structure: ##STR6## where n is an integer sufficient to provide a structure having an average molecular weight of at least 5000.
Claim 14
Dependent Claim 34 words
The method of claim 1 wherein said halogenated polyamic acid comprises the following structure: ##STR7## where n is an integer sufficient to provide a structure having an average molecular weight of at least 5000.
Claim 15
Independent Claim 130 words
A method of metallizing a halogenated polyimide surface comprising: reacting a halogenated polyamic acid with about 0.1 to about 14.0% by weight of added water to form a reaction product; applying a coating of said reaction product over the surface of a substrate about 5 minutes to about 8 hours after adding said water; curing said reaction product coating into a cured layer; post-curing said cured layer into a layer of said halogenated polyimide; treating said surface of said modified polyimide layer with a degreasing agent; treating said degreased surface with an oxidizing agent; contacting said oxidized surface with a mild reducing agent for a time sufficient to remove most of the oxidized residue produced during said oxidation of said surface; and applying a metal layer on said cleaned surface.
Claim 16
Independent Claim 130 words
A method of metallizing a halogenated polyimide surface comprising: reacting a halogenated polyamic acid with about 0.1 to about 14.0% by weight of added water to form a reaction product; applying a coating of said reaction product over the surface of a substrate about 5 minutes to about 8 hours after adding said water; curing said reaction product coating into a cured layer; post-curing said cured layer into a layer of said halogenated polyimide; treating said surface of said modified polyimide layer with a degreasing agent; treating said degreased surface with an oxidizing agent; contacting said oxidized surface with a mild reducing agent for a time sufficient to remove most of the oxidized residue produced during said oxidation of said surface; and applying a metal layer on said cleaned surface.
Claim 17
Dependent Claim 39 words
The method of claim 14 wherein said step of applying said metal layer comprises: electrolessly applying a primary metal layer on said cleaned surface; and electrolessly or electrolytically applying a secondary metal layer on top of said primary layer.
Claim 18
Dependent Claim 21 words
The method of claim 14 wherein said metal layer comprises copper, nickel, gold, silver, platinum, palladium, cobalt or a combination thereof.
Claim 19
Dependent Claim 30 words
The method of claim 14 wherein said metal layer comprises a copper layer in proximate contact with said surface followed by a nickel layer on top of said copper layer.
Claim 20
Dependent Claim 38 words
The method of claim 14 wherein said halogenated polyimide surface having said primary metal layer thereon is heat treated for about 30 minutes to about 48 hours, prior to applying said secondary metal layer on said primary layer.
Claim 21
Dependent Claim 42 words
The method of claim 14 wherein said halogenated polyimide surface is heat treated after applying said secondary metal layer on said primary layer at a temperature of about 45° C. to about 120° C. for about 15 minutes to about 20 hours.
Claim 22
Independent Claim 172 words
A method of improving adhesion of a metal layer on a fluorinated polyimide surface comprising: reacting a fluorinated polyamic acid with about 0.1 to about 14.0% by weight of added water to form a reaction product; applying a coating of said reaction product over the surface of a substrate about 5 minutes to about 8 hours after adding said water; curing said reaction product coating at about 205° C. to about 250° C. for about 2 to 8 hours to form a cured layer; post-curing at about 260° C. to about 357° C. for about 1 hour to about 48 hours said cured layer into a layer of aid fluorinated polyimide; treating said surface of said fluorinated polyimide layer with a degreasing agent; oxidizing said degreased surface with an aqueous solution containing potassium permanganate and sodium hydroxide for about 2.5 minutes; and contacting said oxidized surface with an aqueous solution of a reducing agent for a time sufficient to remove most of the oxidized residue produced during said oxidation of said surface.
Claim 23
Independent Claim 172 words
A method of improving adhesion of a metal layer on a fluorinated polyimide surface comprising: reacting a fluorinated polyamic acid with about 0.1 to about 14.0% by weight of added water to form a reaction product; applying a coating of said reaction product over the surface of a substrate about 5 minutes to about 8 hours after adding said water; curing said reaction product coating at about 205° C. to about 250° C. for about 2 to 8 hours to form a cured layer; post-curing at about 260° C. to about 357° C. for about 1 hour to about 48 hours said cured layer into a layer of aid fluorinated polyimide; treating said surface of said fluorinated polyimide layer with a degreasing agent; oxidizing said degreased surface with an aqueous solution containing potassium permanganate and sodium hydroxide for about 2.5 minutes; and contacting said oxidized surface with an aqueous solution of a reducing agent for a time sufficient to remove most of the oxidized residue produced during said oxidation of said surface.
Claim 24
Dependent Claim 12 words
The method of claim 20 wherein said reducing agent is hydroxylamine hydrochloride.
Claim 25
Dependent Claim 33 words
The method of claim 20 wherein said aqueous solution contains about 3 to about 5 grams per liter of potassium permanganate and about 5 to about 10 grams per liter of sodium hydroxide.

References Cited (Backward Citations)

US3011920A Cited
US3974324A Cited
US3841881A Cited
US4111906A Cited
US4203922A Cited
US4522880A Cited
US4515829A Cited
US4555315A Cited

USPTO Annuity & Maintenance Windows

Annuity Stage Window Opens Payment Deadline Surcharge Period Until Estimated Fee Status
3.5 Years (Year 4) 1997-02-21 1997-08-23 1998-02-22 $2000.00 Window Closed / Lapsed
7.5 Years (Year 8) 2001-02-21 2001-08-23 2002-02-22 $3760.00 Window Closed / Lapsed
11.5 Years (Year 12) 2005-02-21 2005-08-23 2006-02-22 $7700.00 Window Closed / Lapsed

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