Ni–Fe–W alloys were obtained by electroplating using an ammoniacal citrate bath with a cation exchange membrane cell. The addition of 8 atom % iron to the Ni–W alloy (Ni78Fe8normalW14) removed surface microcracks on the deposits and increased the iron content, which was paralleled by an apparent increase in the tungsten content. To improve the microhardness, deposits were heat-treated at various temperatures. The maximum Vickers hardness value of 1350 was obtained after heat-treatment at 500°C . X-ray diffraction analysis revealed that the increasing annealing temperature induced both grain growth and precipitation of new phases, especially NiWO4 . Transmission electron microscopy and selected area diffraction observations revealed that annealing at 500°C led to a significant hardening of the deposits due to the precipitation of new phases with nanosized grains. However, as the annealing temperature was increased above 500°C , the microhardness began to fall with increasing grain size.

Copper via filling by electroplating method became a common technology for interlayer metallization in 3D SiP and then it has been extensively studied. The void free copper via can be obtained with varying the additives on the electrolytes and the current density and mode. The effects of current mode and additives on the copper via filling were investigated. The acid copper electrolytes containing additives were examined to fill 10~20m via hole without void. The different sized vias were successfully filled with copper varying current density and mode after fixing additive conditions. The effect of pulse duty cycle on via filling was also investigated.

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