C4NP - IBM manufacturing & reliability data for lead free flip chip solder bumping

C4NP (C4-New Process) is a novel solder bumping technology developed by IBM and commercialized by Suss MicroTec. C4NP addresses the limitations of existing bumping technologies by enabling low-cost, fine pitch bumping using a variety of lead-free solder alloys. C4NP is a solder transfer technology where molten solder is injected into pre-fabricated and reusable glass templates (molds). The filled mold is inspected prior to solder transfer to the wafer to ensure high final yields. The filled mold and wafer are brought into close proximity and solder bumps are transferred onto the entire 300mm (or smaller) wafer in a single process step without the complexities associated with liquid flux. ©2006 IEEE.