Temp.-resistant connector wire - consists of a highly conductive core and a platinum@-rich mantle into which gold@ has been diffused to allow easier connection

摘要

The electrical conductor wire has a max. dia. of 1.2 mm with a core (2) of pref. Ni or an alloy of Pt with 1-4 wt.% W, and a mantle (1) pref. up to 80 micron thickness, which is coated with a Au layer (3) of 0.05-1 micron thickness, pref. 0.2-0.5 micron. The Au content of the mantle pref. decreases in the direction of the core. The coefft. of thermal expansion (CTE) of the core pref. matches that of the mantle. A mfg. process is also claimed. Into a tube, consisting of Pt, a rod consisting of core material is placed. The workpiece is then drawn into a wire. After formation of the wire a thin Au layer is deposited, pref. 0.05-1 micron thick, pref. by electro-plating, sputtering or evaporation. The wire is then annealed until Au has diffused to the interface between mantle and core. USE/ADVANTAGE - The wire is used for the connection to a measurement resistance, especially a resistance layer. The structure allows easy connection using any of the following techniques : soft-soldering, hard soldering or laser-welding. The wire is easily wetted and does not cause solder contamination with Au, preventing joint brittleness as formed or after high temp. use.