In this study, a free-fall drop tester was studied to test the impact reliability of small electronic components. The electronic component was fixed to the drop table and the table was fallen along guide rods. The impact energy was adjusted by the initial drop height, and the impact duration time was adjusted by inserted soft layers under the drop table. Table acceleration was achieved in the form of a half-sine that conforms to international standards. The developed tester was evaluated by a small printed circuit board. It was observed that the developed tester was fully utilized for the impact reliability assessment of electronic components.

The Flywheel Energy Storage System (FESS) stores the electric energy into the rotational kinetic energy of the rotor. The FESS uses housing components so that the rotor spins inside the housing where the vacuum is maintained. Thus, the housing component is exposed to the load due to this pressure difference, and designing the housing that can efficiently support this load is crucial. Meanwhile, in the situation wherein the rotor lifting force is blocked, the rotor drops and damages the system. Thus, it is necessary to equip a structure capable of supporting the corresponding impact of the rotor drop. In this study, the design of the housing components is described by considering the structural robustness of the housing components, under the atmospheric pressure and impact of the rotor drop. For the pressure load, structural analysis was conducted following the different housing lid shapes: concave, convex, and flat. For the impact of the rotor drop, the structural analysis was conducted following the different terminal velocities of the rotating rotor. As a result, the designed housing components comprise a concave housing lid and the safety suspension 1 mm beneath the rotor. Considering the results, it operates stably under the conditions stated above.