Semiconductor packages having a dam structure

A semiconductor package comprising:

• a substrate having bonding pads at an upper surface thereof;
• a lower semiconductor chip disposed on the substrate and at least one upper semiconductor chip disposed on the lower semiconductor chip;
• an underfill filled between the substrate and the lower semiconductor chip, the underfill including a non-extension portion disposed between the lower semiconductor chip and the bonding pads, and an extension portion having a greater width than the non-extension portion;
• and
• a dam structure disposed on the substrate and having a closed loop shape surrounding the underfill.

A semiconductor package comprising:

• a substrate having bonding pads at an upper surface thereof;
• a lower semiconductor chip mounted on the substrate by flip-chip bonding and an upper semiconductor chip mounted on the lower semiconductor chip by wire bonding;
• an external connection terminal disposed below the substrate;
• a dam structure disposed on the substrate and having a closed loop shape surrounding the lower semiconductor chip, the dam structure including narrow and wide dams, the narrow dam being disposed between the lower semiconductor chip and the bonding pads, and the wide dam having a greater inner width than the narrow dam;
• an underfill disposed inside the dam structure and being filled between the substrate and the lower semiconductor chip;
• and
• an encapsulant covering the substrate, the lower semiconductor chip, and the upper semiconductor chip.