Molecular dynamic simulation of grain size and work temperature effect on mechanical properties of polycrystalline copper
Polycrystalline copper is considered by the industries to be the best TSV electroplating material and other interconnected structure material because of its ultra-low resistivity,high conductivity,low electro-migration rate and good compatibility with the multilayer interconnects process.Its mechanical properties are completely different from the bulk monocrystalline copper,these properties are critically vital to evaluate the thermomechanical reliability of TSV and interconnected structure in 3D packaging.To investigate the effect of the work temperature and grain size on the mechanical properties of polycrystalline Cu,The MD simulations of uniaxial tensile test are performed.The results showed that the elastic modulus gradually increases with the augment of the mean grain size,and the corresponding flow stress concurrently increases,and the flow stress is proportional to the square-root of the grain size,which satisfies the inverse-Hall-Petch relation.It also turned that the elastic modulus decreases with increasing of ambient temperatures,the flow stress is negatively correlated with the temperature.From all the tensile simulation tests,it was confirmed that the mechanism of plastic deformation for polycrystalline copper with 4.65-9.31nm grain sizes is mainly the grains rotation and grain-boundary sliding,the dislocation nucleation and migration is no longer the dominant factor of plastic deformation.
Polycrystalline copper Flow stress Grain size Work temperature Molecular dynamic
Zhiwei ZHANG Pei CHEN Fei QIN
Institute of Electronics Packaging Technology and Reliability College of Mechanical Engineering and Applied Electronics Technology Beijing University of Technology,Beijing,China
国际会议
上海
英文
228-232
2018-08-08（万方平台首次上网日期，不代表论文的发表时间）