Reliability of corner staked surface mount packages

Due to the Restriction of Hazardous Substances by European legislation, Lead free solders such as SAC305 have replaced the use of lead in the commercial electronic industry. Lead free (LF) solder joints, having lower ductility, often are the victims of early failures due to drop events. To improve the drop impact reliability of lead free solder joint, underfill and corner staking were apply to the packages. While, numerous literatures reported that underfill can mitigate the drop reliability, limited corner staking studies have been reported in which most focused on the mitigating the drop impact with corner staking. This paper presents the reliability assessment of corner-staked packages under temperature cycling, harmonic vibration, and drop impact. The test results show that corner staking not only improves the drop impact reliability of surface mount parts but also improves the reliability of parts under vibration and temperature cycling.