Optimizing force and geometry parameters in design of reduced-insertion force connectors

The need to design connectors with large numbers of I/Os is hindered by the associated rise in connector insertion force. It is possible to lower an undesirably high insertion force by reducing the normal force of the contacts, but this raises the question of whether reduced-normal force connectors are sufficiently reliable for telecommunications applications. The authors examined nine test connector designs fabricated with 150-, 75- and 35-g nominal contact normal force, and with 150-, 70-, and 35-mil radii at the point of contact with the pin. The connectors were exposed to conditions of thermal stress (thermal aging and thermal cycling), atmospheric corrosion, and extreme dust contamination coupled with thermal/humidity exposure. Precision resistance measurements were made at various times before, during, and after exposures. All nine designs performed reliably under the test conditions used in this study. The results suggest that connectors which are designed with contact geometries that provide higher local pressures are more effective in overcoming the interference of the dust contamination