基于有限元模拟的微铜柱互连点热失效分析

Thermal Failure Analysis of Micro-Copper Pillar Interconnect Solder Based on Finite Element Simulation

采用有限元模拟法,研究了微铜柱互连点在热冲击载荷条件下的应变和应力,并分析了微互连点的裂纹生长情况。结果表明,封装结构最外侧的微互连点为最易失效互连点(关键互连点)。累积塑性应变能密度主要集中在芯片侧铜焊盘附近,且由外向内逐渐递减,这表明裂纹形成在芯片侧,并沿着焊盘由外向内扩展,最终贯穿整个互连点。试验结果与模拟分析一致,进一步验证了模拟结果对裂纹生长的分析的合理性。

The stress and strain of micro-copper column interconnect solder under thermal shock load were studied by finite element simulation method,and the crack growth of micro-copper column interconnect solder was analyzed.The results show that the interconnect solder located at the outermost of the packaging structure is the most vulnerable interconnect solder(key interconnect solder).The cumulative plastic strain energy density is mainly concentrated near the copper pad on the chip side,and gradually decreases from the outside to the inside,indicating that the crack is formed on the chip side,and expands from the outside to the inside along the pad,and finally runs through the entire interconnection solder.The experimental results are consistent with the simulation analysis,which further verifies the rationality of the simulation results for the analysis of crack growth.