An IC package including a plurality of BGA IC packages stacked on a printed circuit board and a method of manufacturing the same. The IC package includes a printed circuit board, a first BGA IC package, having a plurality of first solder balls, stacked on the printed circuit board, a second BGA IC package, having a plurality of second solder balls, stacked on the first BGA IC package, and an interposer having a plurality of through-holes, which are filled by the second solder balls in a molten state such that the length of the second solder balls increases while the second solder balls harden, the interposer being joined to the top of the first BGA IC package.