A New Non-PRM Bumping Process by Electroplating on Si Die for Three Dimensional Packaging

A new bumping process on a Si die by electroplating without a photo-resist-mold (PRM) was assessed for the three dimensional (3D) stacking of Si dice. In this process, solder bumps were deposited selectively onto the surface of a Cu plugged-through silicon-via (TSV) in a Si die. Since lithography related processes to make a PRM for solder bumping were omitted, it can reduce the production time and cost for bumping. The substrate was a Si wafer, …