Systems and methods for encapsulating a stack of semiconductor dice are described. A stack of semiconductor dice may be formed, for example by attaching die to flexible printed circuit supports attached to frames and stacking the supports, and then encapsulated by flowing a liquid encapsulant around the stack of dice and solidifying the liquid encapsulant. The die supports may contain encapsulant flow openings, such as rectangular slits, that allow the liquid encapsulant to flow around the stack of dice.