关键词: TGV, 跌落冲击, Input-G方法, 有限元仿真, 可靠性, Johnson-Cook本构模型

Abstract: Through-glass via (TGV) technology has become an important development direction of 3D electronic packaging because of its excellent electrical properties and low cost advantages. However, due to the brittleness of its materials, the structure faces reliability challenges when it is subjected to drop impact. Based on the Input-G method, the finite element model of TGV structure is established, and its mechanical response and failure mechanism under dynamic load are systematically studied. The brittle fracture characteristics of glass substrate and the Johnson-Cook constitutive relation of lead-free solder joint at high strain rate are comprehensively considered in the model. The simulation results show that obvious maximum principal stress concentration occurs at the corner of the glass via wall under a 1 500g, 0.5 ms half-sine impact load, with a peak value of 32.9 MPa, indicating that this region is a potential risk area in the TGV structure. The peak maximum principal stress at the neck of the peripheral solder joint reaches 45 MPa and gradually decreases along the diagonal direction. The maximum equivalent stress at the end of copper column is 33.1 MPa, which is lower than the reference value of pure copper yield strength, indicating that the possibility of yield failure of copper column body is low. The future research direction is put forward, with the aim of providing a theoretical basis for the design optimization of highly reliable TGV packages.

Key words: TGV, drop impact, Input-G method, finite element simulation, reliability, Johnson-Cook constitutive model