Modeling of solder joint failure due to PCB bending during drop impact

Reliability of IC packages during drop impact is critical for portable electronic products. These packages are susceptible to solder joint failure when induced by mechanical shock and printed circuit board (PCB) bending during impact. Normally, portable products are designed to withstand a few accidental drops without resulting in major mechanical failure. In this study, we use the ABAQUS/EXPLICIT finite element software to perform the dynamic drop impact simulation. We will use the equivalent layer model for the array of solder columns to simplify the modeling problem. From the analysis, we are able to examine the effects of PCB bending arising from the different number of screws used and the effect of chip location. It is found that PCB bending curvature determines the stress states induced in the solder columns of the IC packages mounted at different locations in the PCB. In addition, the PCB bending curvature can also be used to predict the critical locations where the solder columns will fail first.