Through glass via (TGV) has emerged as a critical solution for next-generation packaging platforms owing to its low dielectric loss, superior coefficient of thermal expansion (CTE) compatibility. Previous studies shows that low thermal conductivity of TGV could lead to thermo-mechanical failures. However, current research on failure behavior of TGV induced by thermal stress structures remains relatively limited. This paper investigates the effects of annealing conditions on residual stress distribution and Cu protrusion behavior in TGV. The evolution of residual stress in top surface of glass substrates under different annealing temperatures and annealing periods was analyzed by nanoindentation, and the corresponding morphological changes of Cu protrusions were characterized by atomic force microscopy (AFM). It is found that annealing helps reduce residual stress on the glass substrate, but prolonged annealing can lead to the generation of residual tensile stress, thereby causing glass cracking; Cu protrusion height increases with annealing period but shows a decreasing growth rate. A creep rate model is established, achieving a RMSE of 1.143 for TGV creep behavior. A quantitative correlation model for the liner relationship residual stress and the Cu protrusion height is proposed. These results provide theoretical guidance for TGV reliability assessment and thermal optimization design.
Wang et al. (Fri,) studied this question.