Dynamic study and structure enhancement of small outline dual-in-line memory module

The purpose of this research is to enhance the structure of the 204-pin small outline dual in-line memory module (SODIMM) against the drop impact. According to the JEDEC regulations, the enhancement of PCB clips should be attempted to increase the resistance against drop impact. From high speed camera observation, the SODIMM module is pushed away from the PCB clips during drop impact. Therefore, the board pushing experiment was performed to measure the resistant force against PCB clips. Thereafter, two stages of finite element analysis (FEA) were executed to improve the resistance force of PCB clips. In the first stage, the finite element model of the SODIMM module was built to calculate the total resistance force against the constraint of PCB clips using FEA software ANSYSreg. The simulation results were validated well with the board pushing experiment. The total resistance force is about 5.39 N in the original design. The second stage of the analysis is to proceed with the structural enhancement of PCB clips. Several parametric studies including discussions on the angle between clip and PCB, the length of the PCB clip, and the material properties of clip, were performed to improve the strength of clips. After the structural optimization, the total resistant force against the constraint of clip increased from 5.39 N to 8 N.