动态力学分析法测量蛇形互连铜导线疲劳性能

Dynamic mechanics method to measure the fatigue performance of snake-shaped interconnected copper conductors

铜导线的疲劳性能是影响柔性电子设备使用寿命和可靠性的关键因素,因此提出对膜-基结构疲劳性能定量测试方法。首先采用纳米动态力学分析技术,分析柔性基底上沉积厚度为25~400 nm铜导线的粘弹性参数变化规律,确定膜-基结构的疲劳寿命。其次通过扫描电子显微镜(SEM)观察分析铜导线的微观晶粒结构,探究导线厚度影响膜-基结构疲劳性能的机理。最后对不同厚度铜导线的测试结果进行分析总结,优化柔性电子器件长度尺度工艺设计参数。结果表明,沉积100 nm以上厚度铜导线疲劳寿命在数百万次,晶粒分布均匀,平均晶粒尺寸为50 nm,晶粒的稳定分布抑制位错运动,疲劳性能可靠。因此柔性基底上沉积100 nm厚度的铜导线在提高柔性电子器件使用寿命方面极具优势。

The fatigue performance of copper conductor is a key factor affecting the service life and reliability of flexible electronic equipment. Therefore, a quantitative test method for the fatigue performance of membrane-base structures is proposed. Firstly, the variation rule of viscoelastic parameters of copper wires with deposition thickness of 25 nm to 400 nm on flexible substrate was analyzed by using nanometer dynamic mechanical analysis technology, and the fatigue life of membrane-base structure was determined. Secondly, the microstructure of copper wires was observed and analyzed by scanning electron microscope(SEM) to explore the mechanism of wire thickness affecting the fatigue performance of membrane-base structure. Finally, the test results of copper wires with different thickness are analyzed and summarized to optimize the length and scale process design parameters of flexible electronic devices. The results show that the fatigue life of copper wires with the thickness of more than 100 nm is millions of times, the grain distribution is uniform, the average grain size is 50 nm, the stable distribution of the grain inhibits dislocation movement, and the fatigue performance is reliable. Therefore, copper wires with a thickness of 100 nm deposited on the flexible substrate have great advantages in improving the service life of flexible electronic devices.