Modeling of dynamic response of desktop computer’s motherboard due to drop impact

Abstract

Electronic products fit into the customer and variable market segments around the world. Reliability of products such as computers, laptop computers, digital cameras, calculators, mobile phones, and other electronic products have become a major concern recently. In this research, detailed drop test simulations are performed using ABAQUS 6.8 finite element software to investigate transient dynamic response of the motherboard based on specifications obtained from the JEDEC Standard. The aim is to evaluate the deformation of the portion motherboard and distribution of stresses in the solder balls interconnection. These connections are the weakest link in the system so realibility of the entire system depends on them. The effects of drop orientations and position of package on board. are also studied. The accuracy of finite element simulation results usually depends on element size control. Therefore, mesh sensitivity analysis was conducted on the finite element model. The simulation results show that at specific time, the model impact to the rigid floor and the stress begins to develop at the lower corner of the board. The board experiences small bending because the lower corner is suddenly impact brought to rest while the other part on the board is still travelling downwards with maximum velocity. At the end of the simulation, the model up, bounce away from the floor under a free vibration condition. Package located at lower corner of the board experince the greatest stress wave transmision than the those at the centre and upper part in 450 drop orientation. For vertical drop direction, package at the upper edge undergoes the largest stress compared to the others. Varying the drop orientation angle from 450 to 900 will produce great stress wave transmission into the solder joints through the board.