Study on the Contact Performance of Electronic EON Connectors Under Axial Vibration

One of the main failure mechanisms of electronic connectors is fretting wear induced by vibration. In this paper, three connectors having different eye-of-needle (EON) pins were investigated for their mating and vibration performances with assembling of different sized and surface-treated printed circuit boards (PCB). In addition to experimental measurement, quasi-static finite-element analysis was also employed in the study of the mating between the EON pin and PCB hole. The results indicated that the retention force was higher when the EON pin was assembled with larger sized hole under lower bound specification. Therefore, higher retention force can be maintained by using appropriate-sized hole or interference. Moreover, according to analysis of variance based on the performance characteristics of retention force and electrical contact resistance, the significance of design factors, i.e., PCB hole size and surface treatment, could be evaluated. Finally, in the vibration test, the sinusoidal excitation level was normalized in accordance with the above experimental results in the retention force of each connector. It was found that under the constant EON size, hole size was the significant control factor in the retention force of mating pair. On the other hand, surface treatment was the significant control factor in the electrical contact resistance. Under vibration test, the control factor of surface treatment on the PCB panel was more significant in determining the electrical contact resistance of the connector than the interference factor.