Contact point for printed circuit board testing - with hard plated nickel layer on piston and sleeve contact faces

摘要

A contact point, esp. for use as a probe when testing printed circuit boards, consists of a tubular container in which a spring loaded piston with a protruding contact point is slideably guided. Both the contact piston and the inside walls of the container along its contact with the piston are hard plated by a chemically applied nickel coating of over 800 HV (over 1000 HV) surface hardness. The hard nickel layer has pref. an admixture of phosphorus or boron. Tests have shown that this prevents fretting and raises the life to several million working strokes.