Formation of a metal/epoxy resin interface

Interfaces between cross-linked polymers and metals play a significant role in fields like splicing and coating, metallization of plastics, microelectronics, micro system technology and nanotechnology. In this paper, we present investigations on the interface formation due to metallization (Au, Ag, Cu and Al) by evapouration of the highly cured epoxy resin system diglycidilether of bisphenol a (DGEBA)-diethylene triamine (DETA) with the focus on the structure formation at the interface. A combination of X-ray photoelectron spectroscopy (XPS), transmission electron microscopy (TEM), atomic force microscopy (AFM) and a radiotracer technique was used to analyze the metal/epoxy interface. While a strong metal/epoxy interaction was found for Al, the noble metals Au, Ag and Cu grow in a Volmer-Weber mode due to an interplay of surface diffusion and metal cluster growth. Nevertheless, polymer bulk diffusion of these metals is negligible.