Fatigue life estimations of solid-state drives with dummy solder balls under vibration

• Effect of dummy solder ball on fatigue life of solid-state drives was studied.
• Global–local FEA was conducted to calculate accurate stress in solder balls.
• S–N curve of SAC 305 in a real product was obtained.
• Applying dummy solder balls increased the fatigue life of SSDs significantly.

An investigation of the effect of dummy solder balls on the fatigue life of a solid-state drive (SSD) under vibration was studied. Finite element analysis and forced vibration experiments of an SSD were conducted to evaluate the fatigue life of an SSD. Global–local analysis techniques were adopted in the finite element analysis to calculate the stress of the solder balls in the SSD. In the vibration experiments, the SSD with dummy solder balls was excited via a sinusoidal sweep vibration around the first resonant frequency until the SSD failed. Using the stress results from global–local analysis and the cycle to failure results from the experiment, an S–N curve was derived for the SSD. This study showed that the solder joints at the corners of the controller package were the most vulnerable components, and that applying the dummy solder balls to those areas decreased the stress of the solder balls and increased the fatigue life of the SSD.