  In multilevel 3D integrated packaging, three major microstructures are viable
due to the application of low volume of solders in different sizes, and/or
processing conditions. Thermodynamics and kinetics of binary compounds in
Cu/Sn/Cu low volume interconnection is taken into account. We show that current
crowding effects can induce a driving force to cause excess vacancies saturate
and ultimately cluster in the form of microvoids. A kinetic analysis is
performed for electromigration mediated intermetallic growth using
multi-phase-field approach. Faster growth of intermetallic compounds (IMCs) in
anode layer in the expense of shrinkage of cathode IMC layer in shown. This
work paves the road for computationally study the ductile failure due to
formation of microvoids in low volume solder interconnects in 3DICs.
