The investigation of interfacial and crystallographic observation in the Ni(V)/SAC/OSP Cu solder joints with high and low silver content during thermal cycling test

Scaling effect on Ag3Sn growth behaviours in micro-joints for flip chip assemblies

“…where I is the original Ag concentration in SAC305 solders; k is the growth-rate constant of (Cu, Ni) 6 Sn 5 ; t (units of min) is the reflow time; ρ i (units of g/cm 3 ) is the density of (Cu, Ni) 6 Sn 5 ; f (units of %) is the weight fraction of Sn in (Cu, Ni) 6 Sn 5 ; h s (units of μm) is the original thickness of SAC305 solders and ρ s (units of g/cm 3 ) is the density of the SAC305 solder. As per our previous studies [25], the value of k for small joints is larger, while the value of h s is smaller during the reflow process.…”

“…Due to environmental concerns and governmental legislation concerning the use of lead in manufacturing, Pb-free solders have replaced traditional lead-based solders in a wide array of electronic devices [1,2]. Among these solders, SnAg alloys have been regarded as the most promising substitutes for Sn-Pb solders due to their good mechanical properties, adequate wetting characteristics as well as the comparable melting temperature [3][4][5]. The addition of Ag can not only eliminate the formation of voids in solder matrix but also suppress the formation of Kirkendall voids at the interface [6].…”