Investigation of alternative to gold contact finishes for telecom connector applications

Before introducing any alternative to gold contact finishes for connector contacts, several laboratory tests have to be completed. Such a test program was carried out with Pd finishes, low-carat gold platings, and silver alloy structures, with and without additional electroplated Au layers of 0.1-0.2 mu m thicknesses. The connectors were of two types: one used in telecom PCM (pulse-code-modulation) equipment with 20 contact pairs, the other of the Eurocard connector geometry with 32 contact pairs. Combined testing by wear cycling, humidity and SO/sub 2/ treatments, and applying an ohmic load inside the climatic chambers, is reported. Contact behavior, wear characteristics, and the surface properties of the contacts are studied. Lubrication with a fluorinated composition, giving a liquid-type film on the contact surface, is also investigated.<>