TSV-Free Interposer Manufacturing for Semiconductor Packaging

The patent extracts and eliminates the through silicon via formation process from the interposer manufacturing workflow. Instead of creating vertical vias through the interposer substrate, the invention uses surface-mounted conductive bumps and traces to achieve electrical interconnections, thereby removing the complex drilling, plating, and filling steps associated with TSV fabrication while maintaining reliable electrical connectivity.

The patent inverts the traditional interconnection approach by transitioning from vertical through-substrate vias to horizontal surface-level conductive paths. Rather than drilling holes through the interposer and filling them with conductive material, the method forms conductive traces on the surface and uses bumps for vertical connections only where necessary, effectively reversing the conventional TSV methodology.

The patent replaces expensive, specialized TSV formation equipment with standard, widely-available semiconductor fabrication tools. The method uses conventional photolithography, sputtering, and electroplating equipment that are already present in most semiconductor manufacturing facilities, eliminating the need for costly dedicated TSV drilling and filling machinery while achieving sufficient precision for the application.

The patent makes existing semiconductor fabrication equipment perform multiple functions. Standard photolithography tools that are used for pattern formation are also used for defining conductive trace patterns, and conventional electroplating equipment used for bump formation is also used for via filling when needed. This multi-functional use of equipment eliminates the need for specialized TSV formation equipment.

The patent performs preliminary formation of conductive traces and bumps on the interposer substrate before mounting the semiconductor devices. This allows the interposer to be pre-prepared with all necessary interconnection structures, so that when devices are mounted, electrical connections are established immediately without requiring subsequent via formation or additional processing steps, thereby accelerating production.

The patent merges the formation of conductive traces, bumps, and interconnection structures into a single integrated fabrication sequence. Rather than separately forming vias, then traces, then bumps, the method combines these steps into a unified process flow where photolithography patterns define both traces and via locations, and electroplating simultaneously forms bumps and via fills, reducing total process time.