Aspects of scaling to mesoscale models derived from the molecular scale for understanding epoxy interfaces

Model scaling from the atomistic level up in order to address performance issues is a topic of increasing interest. One type of scaling that is being investigated is a jump from the molecular scale (angstrom scale) to the submicron mesoscale model. Since both are particle methods, the scaling is a simple one of re-definition and re-parameterization of the particle interaction. This paper will cover aspects of the parameterization that we have found to be useful to allow scaling to the mesoscale and the subsequent mechanical response of the copper/epoxy adhesive interface, of practical interest in molding compounds. The maximum scaling achieved has been from the nanometer to submicron scales for an epoxy (increasing the formula weight in the crosslinked epoxy model by a factor of 500-1000). Obtaining larger models is possible with size limitations due to the computer resources available. Investigations in handling mesoscale models to address interface density, crosslinking effects, and roughness will be discussed.