Effects of shock impact repetition frequency on the reliability of component boards

Novel methods to shorten the time needed for reliability evaluation of new electronic devices are being developed by many. For example, it has recently been shown that the method of vibration testing can be employed to produce the same failure modes and mechanisms as the JESD22-B111 compliant drop testers in significantly shorter time. However, the correlation between the vibration cycles-to-failure and the shock impacts-to-failure is still unclear. Therefore the primary objective of the work being reported in this paper has been to clarify the effects of impact repetition frequency on the lifetime and failure modes and mechanisms of electronic component boards. The reliability tests were conducted with four types of packages (BGA144, BGA288, QFN72, and μSMD36) that were soldered onto the JESD22-B111 compliant printed wiring boards. Three shock impact repetition frequencies (0.01 Hz, 0.1 Hz and 1.6 Hz) were used to study the sensitivity of lifetime to time between the shock impacts. A new tester with adjustable impact repetition frequency was developed for this study. The effect of the elevated temperature (100°C) on the reliability of the component boards was also included in the scope of this study in order to study the role of creep relaxation and the restoration processes of solder interconnections on the lifetime of the component boards. The results showed that the impact repetition frequency has a significant effect on the average lifetime in three of the four studied packages despite the fact that the components have different structures and interconnection geometrics. The change of impact repetition frequency did not, however, change the failure modes and mechanisms.