Electromigration on void formation of Sn3Ag1.5Cu FCBGA solder joints

Failure mechanisms of solder interconnects under current stressing in advanced electronic packages

“…Fig. 13 illustrates the effect of EM on a multi-layer UBM film of Ti (0.2-0.5 lm)/Ni(V) (0.325 lm)/Cu (0.5-1.0 lm) [60]. It was found that, after experiencing a downward electron flow, the Ni and Cu constituents in the UBM began to spread into the solder, and the UBM was gradually consumed.…”

“…Elemental mapping at the UBM/IMC interface in a Sn3Ag1.5Cu solder joint after 1967 h under a current density of 1 Â 10 4 A/cm 2 at 150°C[60].…”

Effects of current density on the formation and microstructure of Sn–9Zn, Sn–8Zn–3Bi and Sn–3Ag–0.5Cu solder joints

“…5(c). It was explained that when a solder joint is subjected to a high current density, the drift of metal atoms in the interconnection occurred, which would eventually cause the formation of micro-voids along the cathode side and a pileup or "hillocks"/IMC hill, along the anode side [4,9,45]. Fig.…”

Evaluation of the thermal conductance of flip-chip bonding structure utilizing the measurement based on Fourier’s law of heat conduction at steady-state

“…Such an area-array interconnect technology is originated from the controlled collapse chip connection technique proposed by IBM in the years of 60s 1 which possesses the advantages of high input/output counts, short electrical signal propagation distance, low packaging profile and high packaging efficiency. However, the issues of thermal fatigue induced by the thermal expansion mismatch of chip and substrate, 2,3 electromigration [4][5][6][7][8][9][10][11][12] and thermomigration 4,[10][11][12][13][14][15][16][17][18][19][20][21] are the reliability concerns of flip-chip bonding devices containing solder joints as the interconnect of die and substrate. Insertion of underfill in the gap between die and substrate is a popular method to suppress the thermal fatigue degradation.…”

“…[4][5][6][7][8][9][10][11][12][13][14][15][16][17][18][19][20][21] Thermomigration is usually accompanied with electromigration due to the joule heating effect at the interconnection of the die side of devices. There is no doubt that temperature is one of the key factors affecting these failure phenomena that the increase of temperature accelerates the electromigration failure in solder joints 32 whereas the thermomigration-related studies have reported the threshold values of temperature gradient for triggering the thermomigration failure in solder joints.…”