3D IC Package Stacking with Inner Outer Lead Fingers

The patent transitions from planar two-dimensional packaging to three-dimensional stacking architecture, where multiple semiconductor devices are vertically stacked and interconnected through through-silicon vias (TSVs). This dimensional change enables higher functional integration while controlling package thickness by utilizing the vertical dimension for interconnect pathways rather than expanding the horizontal footprint.

The patent implements nested packaging structures where smaller semiconductor devices are stacked within and upon larger package substrates. Multiple device layers are nested vertically, with each layer containing functional circuits and interconnect structures that are integrated into the overall package hierarchy, thereby achieving high functional integration without proportional increases in package thickness.

The patent utilizes three-dimensional stacking to move interconnect functions from the horizontal plane to the vertical dimension. Through-silicon vias (TSVs) provide vertical interconnect pathways that pass through multiple device layers, enabling signal and power distribution without requiring additional horizontal footprint area. This dimensional transition allows high functional integration within a compact footprint.

The patent employs periodic repetition of interconnect structures at different vertical levels within the stacked package. Multiple layers of pad structures, TSVs, and interconnect traces are periodically arranged across device layers, allowing dense functional integration through vertical periodicity rather than horizontal expansion, thereby reducing footprint area while maintaining high integration.

The patent replaces traditional leadframe-based horizontal lead structures with vertical through-silicon via (TSV) interconnects that pass through multiple device layers. This dimensional change transforms the I/O architecture from planar leadframes to three-dimensional vertical interconnects, enabling high circuit density by providing numerous interconnect pathways through the vertical dimension rather than being constrained by horizontal lead capacity.

The patent segments the interconnect function across multiple vertical layers and distributes I/O pathways through numerous TSVs throughout the stacked structure. Instead of relying on a limited number of leadframe leads, the package utilizes many small-diameter TSVs distributed across multiple device layers, segmenting the interconnect function to achieve high total I/O capacity that supports high circuit density.