Cost, production, and logistics implications of C4NP solder bumping

摘要

The newest generation of bumping technology, called Controlled Collapse Chip Connection: New Process (C4NP), works with lead-free solder alloys. The new process separates the underbump metallization (UBM) deposition from the solder bump deposition, unlike the old process integrating the two. As separated, the UBM may be more easily integrated with redistribution-layer (RDL) metal, and may be done by the wafer fab. Costs are saved by working with pure solder and relatively simpler capital equipment compared to prior approaches.