Simulation Study of the High-G Drop Impact Testing of Microelectronic Packaging Products

In this work, a finite element model of Ball Grid Array (BGA) package is established to predict the solder joint failure under the high-G drop impact test. To be deemed acceptable, the electronic packaging has to sustain the peak acceleration generated during the high-G drop impact test. Unlike the electronic devices intended for mass consumption, the electronic products designed specifically for military and aerospace industry must be capable of operating in very harsh environments, often involving high impact loading. Thus, the packaging encasing those electronic products must exhibit sufficient impact resistance. This has motivated the present study, comprising of finite element modeling and experimental testing. The proposed finite element model is used to simulate the stress distribution of electronic packaging during high-G impact loading. The simulation model is built using ANSYS LS-DYNA, which is also used to analyze the stress values recorded for the electronic packaging. The model not only simulates the high-G impact loading conditions, but also generates the resulting stress distribution. Its reliability is subsequently tested by comparing its output to the results of a high-G drop impact test. In the experiment, the BGA package failure primarily occurs due to the solder joint fracture, but may also involve copper trace cracking. Thus, the simulation results can be used in practice to reduce the impact loading on the solder joints and lower the probability of failure. Moreover, the thickness of the soft dielectric layer can be increased to absorb a greater amount of the impact force. Most importantly, the stress distribution generated by the proposed model can reveal any further weak points in the electronic packaging.