Study on the plasticity enhancing mechanism of silver-based solid solution for electronic packaging

Ag-based solid solutions have gained significant attention in the electronic packaging field due to their remarkable plasticity. In this work, the generalized planar fault energy (GPFE), critical strength and stresses, and electronic properties after adding solutes with different types and size misfits were studied for Ag-based solid solutions. Furthermore, we explored the underlying mechanism behind the impact of solutes on the plasticity of Ag and confirmed it through transmission electron microscopy (TEM) and high-resolution TEM (HRTEM) analyses. Importantly, we introduced the novel concepts of size and chemical misfit factors, electronic factors, and twinning factor into the plasticity enhancement mechanism of Ag-based solution systems. The predictions based on these factors were in agreement with experimental observations using TEM and HRTEM. Remarkably, the (Ag)–Bi system exhibited the lowest critical resolved shear stress for slip and twinning, as well as the most superior plasticity, positioning it as a crucial candidate for future development. This study presents a scientific framework for designing and developing Ag-based solid solutions with excellent plasticity, encompassing size/chemical factors, electronic factors, and twinning factor.