InFO Through-Via Packaging Without Laser Drilling

The patent transitions from planar packaging to three-dimensional stacked packaging architecture. Multiple semiconductor dies are vertically stacked and interconnected through through-silicon vias (TSVs), enabling high-density I/O connections in the vertical dimension rather than spreading pads across a large horizontal area. This dimensional change allows high I/O density while maintaining compact packaging complexity.

The patent implements nested packaging structures where multiple dies are stacked within a single package footprint. Each die contains functional circuits and I/O pads, and they are nested vertically with interconnect structures. This nesting approach achieves high I/O pad density by packing multiple functional units into a compact volume without proportionally increasing packaging complexity.

The patent merges multiple manufacturing operations into integrated process steps. For example, TSV formation combines drilling, plating, and filling operations; die stacking combines bonding, alignment, and interconnection in a single assembly process. This merging reduces the total number of discrete manufacturing steps, lowering production cost and complexity while achieving high I/O pad density.

The patent performs preliminary actions during die fabrication before packaging. TSVs are formed and filled with conductive material during die manufacturing, and test structures are built-in beforehand. This preliminary preparation simplifies subsequent packaging operations, reducing overall production cost and complexity while enabling high I/O density interconnections.

The patent replaces the laser drilling mechanical system with a mechanical drilling and electroplating system. Standard drilling equipment creates via holes with sufficient precision, followed by electroplating to form conductive walls and fill the vias. This substitution eliminates complex laser systems while achieving the required via hole precision through a simpler, more cost-effective manufacturing process.

The patent changes the formation parameters of through vias from laser-based thermal ablation to mechanical drilling with controlled dimensions. Via hole diameter, depth, and positioning are controlled through mechanical drilling parameters and subsequent electroplating thickness control. This parameter change enables precise via formation using conventional, less complex manufacturing equipment and processes.