Computational modelling of the anisotropic conductive adhesive assembly process

Previously developed analytical models of the anisotropic adhesive assembly process have successfully predicted the time for adhesive resin flow out and whether this can be successfully achieved before resin cure. Computational Fluid Dynamics models have also provided significant insights into the effects of the component and substrate bond pad geometry on the resin flow distribution and hence on the resulting final conductive particle distribution. These computational models have however used Newtonian, i.e. non-shear thinning, flow properties for the adhesive materials. This paper will present initial results from the development of more sophisticated models, which include both the non-Newtonian and the temperature dependent flow of the adhesive. Such models can be used to allow a much more detailed investigation of the interactions of the adhesive resin flow characteristics, the component and substrate materials and geometry, and the assembly process parameters. These models, once fully developed and validated, will therefore lead to a better understanding of the assembly process and facilitate establishment of design rules for different applications.