Effect of Test Conditions on Electromigration Reliability of Sn-Ag-Cu Flip-Chip Solder Interconnects

摘要

The high-temperature operation life test (HTOL) was conducted in this paper to study electromigration phenomena of solder interconnects in a flip-chip package assembly. We examined the fatigue reliability and morphological patterns of three solder compositions: Sn-4Ag-0.5Cu, Sn-3.5Ag-1Cu, and Sn-3Ag-1.5Cu, subjected to two test conditions consisting of different average current densities and ambient temperatures (5 kA/cm~2 at 150℃ and 20 kA/cm~2 at 30℃). It is interesting to realize that as the Cu weight content of the solder composition increases, the fatigue life increases under 5 kA/cm~2 at 150℃ but decreases under 20 kA/cm~2 at 30℃. Observed electromigration morphologies along with computed current density and temperature distributions on solder interconnects from the electrothermal coupling analysis were examined, correlated, and discussed.