The methods hereof were developed to fill a need for inspecting electrical contact material in the form of a wire-like strip comprising a substrate or base of nickel, copper, or nickel or copper alloys, and an overlay on one side of such base of a noble metal or a noble metal alloy. The shape of this contact material is designed so the strip can be welded to a spring base oriented such that the noble metal material will make contact to another such contact on another spring. The noble metal material must, therefore, be precisely located on the wire-like strip of contact material. Due to the extremely high gloss of the metal surfaces and the very small size of the wire-like strip, the location of the noble metal on the base often cannot be seen even aided by a microscope. A method was needed whereby one or both of the base and the overlay could be altered so one could be identified from the other and the precise location of the noble metal material on its base be quickly and easily determined.
USPTO Backgrounds
USPTO Backgrounds