Modeling the Microstructure of Polycrystalline Sn–Ag–Cu Solders

Sn–Ag–Cu solder joints used in electronic packaging typically consist of only a few highly anisotropic grains. The unique grain structure of each joint leads to stochastic variations in its deformation behavior. This work aims to investigate the variability of the deformation response of such solder joints under creep conditions. We will synthesize its microstructure with grains and grain boundaries using Voronoi tessellation algorithms. Each solder grain contains 96.5% tin of body centered tetragonal crystal structure, highly anisotropic in its deformation behavior. Therefore, we will apply constitutive models for anisotropic elasticity and creep. We will demonstrate creep simulations for representative volume elements with randomly selected microstructures. Results and conclusions on expected joint-to-joint variability of the creep response will be discussed.