Method of preparing polymer surfaces for subsequent plating thereon and improved metal-plated plastic articles made therefrom

Abstract

Method of modifying an aromatic polymer surface to improve adhesion of a metal layer thereon and to the articles produced therefrom. The surface of the aromatic polymer such as polycarbonate, is nitrated by a contact with a nitrating solution such as a mixture of nitric and sulfuric acid and then hydroxylated by a contact with a hydroxylating solution such as ammonium hydroxide. The hydroxlyated surface is thus chemically modified to become hydrophilic. The chemically modified surface is electrolessly plated with a primary metal layer. A secondary metal layer is then electrolessly or electrolytically applied on top of the primary metal layer until a metal layer of a desired thickness is attained. The present invention further discloses articles such as an EMI shielded enclosure or a printed circuit board having metal layers as an EMI shield or a conductive metal trace pattern respectively.

Dependencies are inferred from the claim text.