基于纳米压痕法分析无铅焊点内Cu6Sn5金属化合物的力学性能

采用纳米压痕技术对微电子封装中无铅焊点内界面化合物(IMC) Cu6Sn5的弹性模量和硬度进行了测试.根据实际工业工艺流程和服役工况,制备接近真实服役状态下的微电子封装中无铅焊点界面化合物试样;采用扫描电镜(SEM)和能量色散X射线荧光光谱仪(EDX)确定IMC的形貌和化学成分；利用连续刚度测量(CSM)技术,采用不同的加载速率对无铅焊点(Sn3.0Ag0.5Cu、Sn0.7Cu和Sn3.5Ag)内的界面化合物Cu6Sn5进行测量,得到载荷、硬度和弹性模量-位移曲线.根据纳米压痕结果确定Cu6Sn5的蠕变应力指数.

Nanoindentation Identifications of Mechanical Properties of Cu6Sn5 Intermetallic Compounds Derived by Lead-Free Solder Joints

Magnesium (AZ91D) matrix nanocomposite reinforced with nano-sized SiC particles (n-SiCp) was prepared by mechanical stirring and high intensity ultrasonic dispersion assisted casting. The tensile properties and fracture behavior of the magnesium alloy and its nanocomposites at elevated temperature were investigated. The results show that the addition of n-SiCp to AZ91D can improve the tensile strength of the nanocomposites, especially at high temperature. Furthermore the significant improvement of the elongation of the nanocomposites at high temperature is achieved, which results in the quite good ductility at elevated temperature. The fracture analysis on the nanocomposites shows that the fracture mechanism of the nanocomposites changes gradually from the brittle fracture at room temperature to the typical tough fracture at high temperature due to the addition of n-SiCp.