Electroless Plating of Copper and Nickel on Surface-Modified Poly(tetrafluoroethylene) Films

Abstract

Chemical modification of Ar plasma-pretreated poly(tetrafluoroethylene) (PTFE) film by UV-induced graft copolymerization with glycidyl methacrylate (GMA), followed by reactive coupling of 3-aminopropyltriethoxysilane (APS), or reactive immobilization of polyaniline (PANI) chains had been carried out to improve the adhesion of the electrolessly deposited copper and nickel to PTFE film. The surface compositions and microstructures of the modified PTFE films were characterized by X-ray photoelectron spectroscopy (XPS) and atomic force microscopy (AFM), respectively. The PANI-modified PTFE surface was susceptible to the electroless deposition of copper and nickel in the absence of sensitization by The adhesion strength of the PANI-modified or silane-modified PTFE film with the electrolessly deposited metal was affected by the graft concentration of the GMA polymer, the Ar plasma post-treatment, the graft-modified PTFE surface, and the extent of thermal post-treatment after metallization. The optimum T-peel adhesion strength of the electrolessly deposited metal on the graft-copolymerized and APS-coupled PTFE film could reach about 13 N/cm. This adhesion strength represented a more than tenfold increase over that obtained when the PTFE film was modified by Ar plasma treatment alone. The mechanisms of the adhesion strength enhancement, thermal stability enhancement, and cohesive failure of the metal-PTFE interface were also investigated. © 2001 The Electrochemical Society. All rights reserved.