Cu/SnAgCu/Cu TLP with different thicknesses for 3D IC

This paper aims to investigate Cu/SnAgCu/Cu transient liquid phase (TLP) bonding with different thicknesses for three-dimensional (3D) integrated circuit (IC).

This paper includes experiments and finite element simulation.

The growth rate of the intermetallic compound layer during TLP soldering was calculated to be 0.6 μm/s, and the small scallop-type morphology Cu₆Sn₅ grains can be observed. With the decrease in thickness in solder joint, the thickness of intermetallic compounds represents the same size and morphology, but the size of eutectic particles (Ag₃Sn, Cu₆Sn₅) in the matrix microstructure decrease obviously. It is found that with the increase in thickness, the tensile strength drops obviously. Based on finite element simulation, the smaller value of von Mises demonstrated that the more reliability of lead-free solder joints in 3D IC.

The Cu/SnAgCu/CuTLPbondingwithdifferentthicknessesfor3D IC was investigated.