Development of a new self-assembled die bonder to three-dimensionally stack known good dies in batch

We developed a new self-assembled die bonder to produce three-dimensionally integrated circuit (3D IC) using a multichip-to-wafer bonding method in batch. In the self-assembled multichip bonder, large number of known good dies (KGDs) can be simultaneously transferred to an LSI wafer on which hydrophilic bonding areas with liquid droplets are prepared. The many KGD can be aligned to the bonding areas by the liquid surface tension. The average alignment accuracy was found to be approximately 400 nm and the total alignment time was less than 0.1 sec. After liquid evaporation, the many KGDs can be bonded to the bonding areas in the new self-assembled die bonder.