Structure and formation of metal - polymer interfaces

This paper reviews how structure and formation of metal-polymer interfaces are controlled by the preparation process and the nature of the materials involved. Emphasis is placed on noble-metal deposition onto fully cured polymers with a focus on results from radiotracer measurements of metal diffusion at the interface, structural investigations by means of electron microscopy, and computer simulations. Moreover, first results from X-ray photoemission spectroscopy and other techniques on the early stages of interface formation are presented. While reactive metals always seem to form relatively sharp interfaces with polymers, metals of lower reactivity diffuse into them at elevated temperatures and tend to agglomerate. The extent of diffusion appears to be determined by the initial stage of the deposition process and increases strongly at low deposition rates, where a large fraction of isolated metal atoms is able to diffuse into the polymer before being trapped by other atoms at or near the surface. No significant diffusion is expected from a continuous metal Aim as a consequence of the high cohesive energy of the metal.