By EV Group
One hybrid die-to-wafer bonding method that has already been implemented in limited volume production for the past few years for applications such as silicon photonics is collective die-to-wafer (Co-D2W) bonding. In Co-D2W bonding, multiple dies are transferred to the final wafer in a single process step. The manufacturing flow for the Co-D2W bonding process is shown in the figure below and consists of four major segments: carrier preparation, carrier population, wafer bonding (temporary and permanent) and carrier separation. Transfer Method: Collective Die Transfer by Reconstituted Carrier Pros: - Proven technology - Die Activation and cleaning equivalent to W2W hybrid bonding - Oxide management - Rework on carrier feasible Cons: - Error propagation of D2W + W2W alignment - Cost of carrier prep, utilization and clean - Die thickness needs to be in narrow range
