High Density Solder Bump Interconnect for MEMS Hybrid Integration

Ultra high-density hybrid integration for MEMS mirror chips with several thousand I/Os has been developed. The integration scheme involving flip-chip assembly provides electrical signal to individual mirrors, which is compatible with post processing steps of selectively removing the silicon handle and releasing the MEMS mirrors. For the first time, to our knowledge, solder deposition and flip-chip bonding of 3µm bumps on 5µm centers of a large array has been demonstrated.