Effect of Shock Pulse Variation on Surface Mount Electronics under High-G Shock

Abstract

In defense and aerospace applications, the electronic components may be exposed to very high-G forces in comparison with commercial electronic applications. Commercial Electronic parts are increasingly being used in high-G fuzing applications, hence survivability of electronic components has direct impact on the system reliability. In operating environments, high-G shock pulses can vary from few milliseconds to microseconds. The damage to the electronic components directly depends on the duration of exposure to the high-G forces (i.e. Shock pulse width). Under high-G shocks, the effect of varying shock pulse widths has not been studied and defined yet. Data on the effect of shock pulse will be useful in improving the design characteristics of the board and in choosing restraint mechanisms. The advantage of using restraint mechanisms along with the effects of high-G forces with varying shock pulses for fine pitch BGAs is a new study. In this study, the effect of varying shock pulses has been taken into account, while the prior works on high-G forces have not included it. All the test assemblies are restrained with potting which has been studied, under the effects of high-G forces with varying shock pulse durations. In addition to that, high voltage, multilayer ceramic 3640 capacitors are mounted and tested passively under high-G conditions along with the packages for reliability. In this paper, with respect to the end application in Defense and Aerospace systems, a circular test board has been used. All the potted printed circuit boards are tested along with high Voltage, multilayer ceramic 3640 capacitors have been mounted on to the test vehicles along with the packages to test reliability under high-G shock levels up to 25,000g.