Surface Modification of Tetrafluoroethylene−Perfluoroalkyl Vinyl Ether Copolymer (PFA) by Remote Hydrogen Plasma and Surface Metallization with Electroless Plating of Copper Metal

Abstract

PFA sheets were modified with remote hydrogen plasma, and effects of the modification on the adhesion between copper layer and FEP were investigated. Remote hydrogen plasma treatment for a short time of 30 s is able to make the PFA surface hydrophilic. The remote hydrogen plasma treatment causes defluorination and oxidation of PFA surface. The extent of the defluorination is 42−48%, and the oxidation reaches 9−13% of the total carbon atoms. The modification of the PFA surface by the remote hydrogen plasma is effective in the adhesion to copper metal. The peel strength for the copper metal/PFA system is improved from 0 to 101 mN/5 mm by the surface modification. The failure mode of the copper metal/PFA system is an inner layer of the plasma-treated PFA layer. The remote hydrogen plasma treatment is the preferable pretreatment of the PFA surface for adhesion with copper metal.