Shearing Speed Stress Comparison between Sn-3.9Ag-0.6Cu and Sn-3.5Ag-0.7Cu Solder Ball

The reliability of the solder joints of Ball Grid Array is severely tested during the exposure of thermal operation due to coefficient of thermal expansion (CTE). Different thermal expansion due to this mismatch causes shearing effects to the solder joints. This paper compares the shearing speed on stress and strain between Sn-3.9Ag-0.6Cu and Sn-3.5Ag-0.7Cu solder ball. A full factorial design of experiment was used to compute the interactions between the factors on each response using a finite element analysis software, Ansys. It is found out that Sn-3.5Ag-0.7Cu solder ball contributes higher stress. On the other hand, Von-Mises stress and equivalent plastic strain increases in parallel with the increasing of the shear speed.