Shear Response and Local Structural Evolution of Through‐Glass Vias (TGVs) in Borosilicate Glasses: A Molecular Dynamics Study

ABSTRACT

Through‐glass vias (TGVs) are critical to high‐density three‐dimensional interconnects for advanced glass packaging; however, the local structural response of vias to mechanical loading remains poorly understood. Here, we employ molecular dynamics simulations to investigate the shear behavior and structural evolution of two commercial borosilicate glasses, SCHOTT Borofloat 33 and N‐BK7, comparing bulk and TGV configurations. The introduction of TGVs markedly reduces the shear strength of both glasses, narrows the modulus gap between them, and reverses their shear‐modulus ranking, while simultaneously amplifying the spatial heterogeneity of local deformation. Structural analysis indicates that shear loading does not globally reconstruct the glass network; rather, it enhances short‐range structural fluctuations and induces limited medium‐range topological rearrangements. At the TGV scale, the nonbridging oxygen content increases and the Si‐Q ⁴ fraction decreases, reflecting reduced network connectivity, whereas changes in B ⁴ species point to selective rearrangement of the local BO ₄ environment. Decomposition of Si‐Q ⁿ and B‐Q ⁿ species, combined with ring‐structure analysis, reveals that the B–O network is preferentially sensitive to both via introduction and shear perturbation relative to the Si–O network. This behavior highlights a selective role of B–O units in accommodating medium‐range structural rearrangements in borosilicate glasses. Collectively, these findings provide atomic‐scale insight into the shear reliability of borosilicate TGVs and their local structural accommodation mechanisms.