The stack package includes a substrate body layer having a top surface and a bottom surface, first circuit patterns disposed on the bottom surface of the substrate body layer, second circuit patterns disposed on the top surface of the substrate body layer, a first semiconductor chip including first bumps, and a second semiconductor chip including second bumps. The first bumps extend through the substrate body layer to be electrically coupled to the first circuit patterns, and the second bumps extend past sidewalls of the first semiconductor chip to be electrically coupled to the second circuit patterns. The second semiconductor chip is stacked on the first semiconductor chip.