Failure analysis of solder interconnects under the electro-thermal-mechanical coupling tests

In this paper, solder interconnects reliability for board-level packaging is studied under the coupling tests. A set of temperature and vibration (T-V) tests are designed to study the effect of temperature on solder interconnects life and failure modes. The electro-temperature-vibration (E-T-V) coupling tests are conducted to analyze the influence of electric current on solder interconnects reliability. Results show that the life of solder interconnects subjected to vibration loading is improved with temperature rise from 25°C to 100°C. Temperature dominates the solder joint failure mode. The crack is shifted from the interface between the IMC and copper pad to the bulk solder. Compared to the T-V coupling test, the life under the E-T-V coupling test is increased with the increase of electric current density from 0.8*10⁴A/cm² to 1*10⁴/cm². The Cu pad at the cathode is consumed dramatically, the thickness of interface IMC at the anode is significantly increased. The obvious electro-migration phenomenon takes place.