A New D2W Bonding Alignment Scheme Using Magnetic and Capillary Assisted Self-Alignment

Conventional alignment technologies of D2W (Die to Wafer) bonding have been developed by improving an optical vision system and the precision of bonding head and stage. As an alternative scheme, we newly proposed a disruptive alignment scheme. It utilizes both magnetic and capillary forces simultaneously, which can actively control the magnetic force through magnetic align patterns in a die. The mechanism of the scheme was investigated using analytical, computational, and experimental methods. To confirm the feasibility of the scheme, we optimized the selection of magnetic material and the pattern dimension as TSV to maximize the magnetic force, and successfully fabricated die sample with TSV filling with magnetic material. Using this scheme, we confirmed that the misalignment could be about 2.6% of magnetic TSV diameter, implying that further improved alignment might be achieved using the down -scaled magnetic align pattern.