Abstract A method for attaching adherent metal components, particularly a copper film, on at least one surface of a polyimide substrate is provided. The method comprises the steps of: exposing at least one surface of the polyimide substrate to a reactive gas plasma that provides a level of ion bombardment of the polyimide surface sufficient to disrupt at least a portion of the imide groups on the surface and to form reactive carboxylate groups, carbonyl groups and other carbon-oxygen functional groups on the surface; and then depositing a metal film onto the chemically-modified surface without intervening exposure to air. The present invention also provides a copper-coated polyimide product comprising a polyimide substrate having a substantially smooth and chemically-modified surface and a copper film directly attached to the surface, i.e., the product is free of a polymeric adhesive layer or tie coat between the surface of the polyimide substrate and the copper film.
A copper-coated polyimide product comprising; a polyimide substrate having a substantially smooth surface; and a copper film attached to the substrate surface; wherein a portion of the copper atoms in the copper film are chemically bonded to functional groups of the polyimide at the surface; said copper being attached to the polyimide surface by the steps of: (a) exposing at least one surface of the polyimide substrate to a reactive gas plasma that provides a level of ion bombardment of at least 5×10 17 eV/liter-atm, wherein the level of ion bombardment is represented by the expression: (q)×(n + )×(φ f )/p; where q=the unit electronic charge (equal to 1 for units of eV/liter-atm); n + =the number density of positive ions in the plasma (liter −1 ); (φ f )=the potential difference between the plasma and the polyimide surface (volts); and p=pressure in atmospheres; and (b) then depositing a copper film onto the ion-bombarded surface without intervening exposure to air.
Claim 2
Dependent Claim
160 words
A copper-coated polyimide product comprising; a polyimide substrate having a substantially smooth surface; and a copper film attached to the substrate surface; wherein a portion of the copper atoms in the copper film are chemically bonded to functional groups of the polyimide at the surface; said copper being attached to the polyimide surface by the steps of: (a) exposing at least one surface of the polyimide substrate to a reactive gas plasma that provides a level of ion bombardment of at least 5×10 17 eV/liter-atm, wherein the level of ion bombardment is represented by the expression: (q)×(n + )×(φ f )/p; where q=the unit electronic charge (equal to 1 for units of eV/liter-atm); n + =the number density of positive ions in the plasma (liter −1 ); (φ f )=the potential difference between the plasma and the polyimide surface (volts); and p=pressure in atmospheres; and (b) then depositing a copper film onto the ion-bombarded surface without intervening exposure to air.
Claim 3
Dependent Claim
87 words
A copper-coated polyimide product comprising; a polyimide substrate having a substantially smooth surface; and a copper film attached to the substrate surface; wherein a portion of the copper atoms in the copper film are chemically-bonded to functional groups of the polyimide at the surface; said copper being attached to the polyimide surface by the steps of: (a) exposing the polyimide substrate to a reactive gas plasma comprising oxygen ions or nitrogen ions; and (b) then depositing a copper film onto the surface without intervening exposure to air.
Claim 4
Dependent Claim
87 words
A copper-coated polyimide product comprising; a polyimide substrate having a substantially smooth surface; and a copper film attached to the substrate surface; wherein a portion of the copper atoms in the copper film are chemically-bonded to functional groups of the polyimide at the surface; said copper being attached to the polyimide surface by the steps of: (a) exposing the polyimide substrate to a reactive gas plasma comprising oxygen ions or nitrogen ions; and (b) then depositing a copper film onto the surface without intervening exposure to air.