Method of treating halogenated polyimide substrates for increasing adhesion of metal layer thereon
AssigneeGeneral Electric Company
InventorsCharles E. Baumgartner, Lisa R. Scott
Life of this patent
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Abstract
Method of producing a polyimide layer having improved adhesion to a metal layer thereon. A halogenated polyamic acid is sprayed, partially cured, degreased and oxidized to form a partially cured polyimide layer, which is then electrolessly plated with a primary metal layer and then final cured into the polyimide layer. Electrolessly or electrolytically applied secondary metal layers are then deposited on the primary layer, 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.
Claims20
A method of metallizing a halogenated polyimide layer comprising:
- applying a coating of a halogenated polyamic acid over the surface of a substrate;
- partially curing said coating at a temperature in the range of 205.degree.-250.degree. C. into a partially cured halogenated polyimide layer;
- treating the surface of said partially cured halogenated polyimide layer with a degreasing agent;
- treating said degreased surface with an oxidizing agent;
- applying a primary electroless copper or nickel layer on said oxidized surface;
- curing said partially cured halogenated polyimide layer into said halogenated polyimide layer in a final curing step after application of said electroless layer;
- and
- applying a secondary metal layer on said primary metal layer after said final curing step.
A method of metallizing a halogenated polyimide layer comprising:
- applying a coating of a halogenated polyamic acid over the surface of a substrate heated to about 207.degree. C. to 246.degree. C.;
- partially curing said coating at a temperature in the range of 205.degree.-250.degree. C. into a partially cured halogenated polyimide layer;
- treating the surface of said partially cured halogenated 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;
- applying a primary electroless copper or nickel layer on said oxidized surface;
- curing said partially cured halogenated polyimide layer into said halogenated polyimide layer in a final curing step under an inert atmosphere after application of said electroless layer;
- and
- electrolessly or electrolytically applying a secondary metal layer on top of said primary metal layer after said final curing step.
Dependencies are inferred from the claim text.