关键词: 有限元分析, 异构集成, 可靠性, 热循环

Abstract: Against the backdrop of continuous evolution in electronic packaging technologies, advanced 3D‑IC heterogeneous integration technologies such as 3D Fabric‑SoIC, InFO, X‑Cube, Chiplet, EMIB, and Foveros have enabled wafer‑level packaging (WLP) and chip‑level integration schemes including WtW (wafer‑to‑wafer), WtD (wafer‑to‑die), and SoC (system‑on‑chip). This study focuses on the new requirements for solder joint performance imposed by 2.5D/3D packaging technologies. Using Ansys finite element analysis software and following the MIL‑STD‑883 standard, a thermal cycling load (-55 ℃ to 125  ℃) was established, and the solder joint arrays of three package models were solved. The effects of thermal cycling on the solder joint reliability of three different integration schemes were investigated, and the stress evolution during the heating and cooling cycles was analyzed. The results indicate that in the through silicon via (TSV) structure, the maximum stress occurs at the corner in contact with the Cu pillar, with the bottom‑layer solder joints being the potential risk area. In the WOB (wire on bump) structure, the double‑chip layer enhances stiffness, significantly reducing the stress of the bottom‑layer solder joints compared to TSV; however, the inner solder joints at the corners of the second layer become stress concentration points due to the full‑contact solder paste mode. In the RDL (redistribution layer) structure, the stress distribution is significantly affected by thermal deformation of the redistribution layer, with the maximum stress first increasing and then decreasing, and the stress concentration locations deviating from the conventional corner rule and shifting toward the center. This study provides a reference for the optimization of solder joint materials and reliability improvement in electronic packaging, and proposes structural design suggestions to avoid solder joint failure.

Key words: finite element analysis, heterogeneous integration, reliability, thermal cycling