Environmental effects on connector reliability

The author examines data gathered from a multiyear in-depth analysis of signal and power connectors used in aircraft as well as connectors used on ground-based computers, flight simulators and test equipment. The equipment was from the period 1954-1986 and included a wide range of connector technologies and connector finishes including gold, silver, rhodium, and tin. All types of connectors were evaluated including circular, rectangular, card edge, ZIF, and RF connectors of both military and commercial type. Analysis of field failures was performed using SEM (scanning electron microscope) and EDX technology. Gold over nickel plating showed the best performance of all of the finishes. It shows the capability to resist corrosion even after many years, and with a nonporous nickel underplate there is no diffusion of base metals through the gold