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

摘要

Method of modifying a polycarbonate surface to improve adhesion of a metal layer thereon and to the articles produced therefrom. The surface is first rendered hydrophilic by an exposure to actinic light such as ultraviolet light. The surface is then impregnated with a diffuser such as hydrochloric acid. The surface after impregnation is etched with a base such as potassium hydroxide and cleaned by oxidizing it with a solution of an oxidizing agent such as potassium permanganate. The cleaned surface is then neutralized by contacting it with a mild reducing agent. The chemically and physically 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, a printed circuit board and a reflector for a light emitting device having metal layers as an EMI shield, a conductive metal trace pattern and a reflective surface respectively.