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A higher number of points of contact provide higher reliability in harsher environments and usually provide lower contact resistance.
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Plating
Connectors are often plated with another metal to prevent corrosion. This corrosion happens for certain material when exposed to air - copper will oxidize and turn green very easily. Tin and Gold are often used to plate materials such as copper or brass. This plating layer is a thin layer of metal, often fractions of a micrometer (um) thick which does not corrode, oxidize, or tarnish as easily as copper.
Gold plating is the standard for high reliability connections because of its electrical resistivity and relative softness since a small layer will be scraped off each time you make a new connections, exposing a fresh, new layer of the crimp terminal.
Tin is standard as an economical alternative, though will eventually oxidize with time.
MBI - Blind Mate Interface
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