Characterisation of electroplated NiMn films for wafer probing

Reliability in wafer test is critical for sort yield and the probe life is key to sort the floor performance. Probes made of Ni-alloys are becoming common as increasing parallelism and fine pitch requirements in test transform probe cards into microelectromechanical system products. NiMn probes, with a composition of 0.25 wt% Mn and good spring properties, were developed for high-cycle wafer probe applications. Mechanical properties of electroplated layers were investigated as a function of annealing conditions. A film release process was developed without the use of a sacrificial layer. Microstructural evolution on the film release interface was examined for two different substrates.