Performance of Ni-alloy MEMS-probes coated with PdCo films in semiconductor wafer test

A novel electroplating system and approach for selectively coating of probe tips for wafer and package testing are presented. A Ni-alloy probe tip with an overcoat layer of 3.5um thick PdCo provided less tip wear and better electrical contact resistance performance in wafer testing. Microstructures of films resulting from different conditions of electroplating process were analyzed, most uniform films were obtained at 5 mA of plating current conditions. The probe tip wear throughout probe life testing was monitored which indicates PdCo film with Au underlayer establishes good electrical contacts.