Semiconductor packages with metal posts, memory cards including the same, and electronic systems including the same

A semiconductor package comprising:

• a flexible package substrate including a first surface and a second surface;
• a metal post penetrating the flexible package substrate from the first surface toward the second surface and including a first protrusion that protrudes from the first surface and a second protrusion that protrudes from the second surface;
• a first semiconductor chip connected to the first protrusion;
• a second semiconductor chip connected to the second protrusion;
• a first flexible molding member covering the first semiconductor chip and the first surface of the flexible package substrate;
• a second flexible molding member covering the second semiconductor chip disposed on the second surface of the flexible package substrate;
• an external connection terminal disposed on the second surface of the flexible package substrate;
• and
• a plurality of wiring patterns disposed in the flexible package substrate to connect the metal post to the external connection terminal.