| abstract |
Provided is a die stack structure including a first die and a second die. The first die and the second die are bonded together through a hybrid bonding structure. At least one of a first test pad of the first die or a second test pad of the second die has a protrusion of the at least one of the first test pad or the second test pad, and a bonding insulating layer of the hybrid bonding structure covers and contacts with the protrusion, so that the first test pad and the second test pad are electrically isolated from each other. |