“…Both “adhesive first” or “metal first” methods have to involve a curing procedure in the bonding process, not only raising various problems but also increasing the bonding period. Many attempts have been made to cure the adhesive completely before hybrid bonding [ 9 , 10 ], as shown in Figure 1 c. A high-quality dielectric passivation layer was achieved because the solvent and volatile substances of the adhesive can be removed completely. Among them, polyimide is a promising adhesive due to its advances in flexibility, chemical inertness, mechanical toughness, and thermal stability at high temperatures [ 11 , 12 ], which makes it withstand manufacturing processes such as metal deposition, photolithography, and wet etching processes.…”