Copper wire with thick electroplated tin coatings - where wire is annealed below the m. pt. of tin and has good solderability

摘要

The wire is made by one or two process: (a) A Cu wire is drawn, electroplated with Sn, and annealed; or (b) A Cu wire is electroplated with tin, drawn and annealed. In either case the Cu wire has a softening temp. below the m.pt. of tin, and the wire drawn to final size is annealed at a temp. below the m.pt. of tin for 2-8 hrs. Annealing is pref. at 170-140 degrees C in a non-reducing atmos.; and the Cu wire is electroplated with nickel 2 mu m thick prior to tin plating. Tin coatings 3-7 mu m thick can be obtd. with uniform thickness, providing protection against corrosion and also good solderability in the mfr. of electric conductors and circuits.