T字型硅通孔不同位置界面裂纹扩展研究

Study on Interface Crack Propagation at Different Positions of T-Shaped Through-Silicon Vias

硅通孔(TSV)技术是实现三维封装的关键技术。随着技术发展,TSV被设计成多种不同结构。以T字型TSV为研究对象,仿真分析了两种温度载荷下T字型TSV中产生的热应力及其分布情况。以此为基础,通过计算裂纹尖端能量释放率,研究了T字型TSV中3个不同位置的界面裂纹失效扩展。结果表明,T字型TSV中钉头的存在改变了铜/硅/钉头三重连接处和硅材料顶部钉头外周边界条件,在这两处易产生应力集中现象。与完全填充TSV结构相同位置的垂直裂纹相比,T字型TSV中垂直裂纹能量释放率明显下降。另外,T字型TSV中水平向外开裂的界面裂纹扩展时裂纹尖端能量释放率最小,水平向里开裂的界面裂纹扩展时裂纹尖端能量释放率最大,更易发生失稳扩展。

Through-silicon via(TSV)technology is the key technology of 3 D packaging.With the technology development,TSVs have been designed in various structures.With the T-shaped TSV as the research object,the thermal stress and its distribution in the T-shaped TSV under two different temperature loads were simulated and analyzed.On this basis,the failure propagation of interface cracks at three different positions in the T-shaped TSV were studied by calculating the energy release rate at the crack tip.The results show that the existence of the nail head in the T-shaped TSV changes the boundary conditions of the triple connection of copper/silicon/nail head and the periphery of the nail head at the top of the silicon material,and the stress concentration phenomenon easily occurs in these two places.Compared with the vertical crack at the same position in the fully filled TSV structure,the energy release rates of vertical cracks in the T-shaped TSV obviously decrease.In addition,in the T-shaped TSV,the energy release rate at the crack tip is the lowest when the interface crack is cracked horizontally outward,while the energy release rate at the crack tip is the highest when the interface crack is cracked horizontally inward,which is more prone to unstable propagation of this crack.