Novel EXperimental & Theoretical Group for materials design
次世代材料設計研究群
Electronic research
Electronic packaging
Soldering is the most important interconnection technologies for various levels of electronic packaging. Sn-based Pb-free solders have been widely used for low-temperature soldering. Cu is a commonly used metallization in contact with solders. However, voids and brittle intermetallic compounds usually form at interfaces through interfacial reactions between Sn-based solders and Cu substrates. In our previous work, minor addition of Ga has been found to effectively mitigate the soldering reactions between Sn-58Bi solders and Cu substrates. In addition, the 200 °C isothermal section of the Cu-Ga-Sn ternary system was constructed using CALPHAD-assisted experimental determinations.
From: J.B. Li, L. Ji, J.K. Liang, Y. Zhang, J. Luo, C.R. Lic, G.H. Rao, Calphad-Comput. Coupling Ph. Diagrams Thermochem., 32 (2008) 447-453.
M. Li, Z.M. Du, C.P. Guo, C.R. Li, J. Alloy. Compd., 477 (2009) 104-117.
W. Gierlotka, S.W. Chen, S.K. Lin, J. Mater. Res., 22 (2007) 3158-3165.
T.J. Anderson, I. Ansara, Journal of Phase Equilibria, Vol. 13 (1992) 7.
Electronic packaging
Electromigration
With the continuing miniaturization of integrated circuits, the electric current densities experienced in metallic interconnects in electronic circuits have multiplied. This caused the gradual movement of the ions in a conductor due to the momentum transfer between conducting electrons and diffusing metal atoms. this is called electromigration.
As the device size shrinks, atomic rearrangements and diffusion of atoms in the presence of electric currents become key problems, limiting the device’s mechanical stability and the persistence in time of uniform electron transport properties.
These issues are closely related to the presence of current-generated forces acting on the nuclei.
We now doing the research of current induced force on different material, which using the software implement with non-equilibrium green’s function.
Electromigration
H. Gan and K.N. Tu, Polarity effect of electromigration on kinetics of intermetallic compound formation in Pb-free solder
V-groove samples (2005)
Ferroelectric materials
The dynamics model of domain walls in ferroelectric materials for application of nanoelectronic components is very important. We hope to present the properties of the domain wall by experiment and simulations respectively, and comparing the
measurement results and the calculated results.The results are expected to impact the development of ferroelectric ceramic materials for nano-electronic devices such as Nonvolatile memory, micro-actuators and sensors.
