Research on shear creep properties of SAC305 solder bumps in ball grid array

In this work, shear creep tests for the ball grid array specimens with the diameter of 0.6 mm Sn-3Ag-0.5Cu (SAC305) solder bumps have been conducted at various temperatures (60 °C, 80 °C and 100 °C) and stress levels (7 Mpa, 12 Mpa and 14 MPa) to determine its creep properties. The effects of stress level and temperature on creep strain rate were investigated. Creep constitutive equation of the steady-state creep, together with its stress exponent n, creep activation energy Q and structure constant A were determined by employing the power law creep. The analysis result of the ANSYSTM finite-element analysis software was accordant with the expectation. Compared with specimen with 760 mm, a fairly good agreement in creep behavior could be found.