A Novel Flexible 3-D Heterogeneous Integration Scheme Using Electroless Plating on Chips With Advanced Technology Node

A novel 3-D chip-level heterogeneous integration scheme for low cost and rapid pilot demonstration is proposed in this paper. The conventional Bumping fabrication is done at wafer level. However, due to the high cost of whole wafer, opting for chips with advanced technology node is a better alternative. Therefore, with the difficulties of the bumping process at chip level, 3-D heterogeneous integration by chip stacking faces challenges. This paper presents a novel heterogeneous integration platform by using electroless plating on chips and pillar bump on wafers before stacking. This integration platform can be applied to chip-to-chip or chip-to-wafer scheme when chips are fabricated from costly advanced technology node.