An electronic assembly is assembled by stacking two or more integrated
circuit dies on top of one another. Prior to singulation, an opening is
laser-drilled into an upper die, and subsequently filled with a
conductive member. The conductive member is located on a lower die and
interconnects integrated circuits of the upper and lower dies.
Laser-drilling allows for faster throughput when compared to, for
example, etching, especially if a small number of openings has to be
formed. The opening is laser-drilled from an upper surface of the upper
die all the way through the die, which allows for the use of alignment
marks on an upper surface of the upper die.