Molecular dynamics and discrete element modeling studies of underfill

It is well known that capillary action drives the standard underfill phenonmenon. However, the underlying principles which govern the flow properties and specific formulation tradeoffs are in need of basic understanding. For instance, flow speed, filler settling, filler striation, and voiding are all properties that require a mechanistic understanding; and although binder and filler effects are expected from a combination of surface energy and particle dynamics drivers, the simple identification of the problem does not instruct how to control these effects. For the formulator or the end-use engineer, such understanding must be reduced to controllable variables. In order to address these issues, both molecular modeling and discrete element modeling have been engaged to understand the formulation constituent effects. Both models similarly engage basic Newtonian dynamics to derive multi-body system simulations.