PURPOSE: A heat sink module is provided to improve heat dissipation properties by forming a heat dissipation space for guiding air flow between an inner surface of a second heat dissipation plate and a protrusion end of a heat dissipation plate. CONSTITUTION: A heat sink module(200) comprises a first heat dissipation plate(210), a second heat dissipation plate(220), and a third heat dissipation plate(230). The bottom parts of the first heat dissipation plate and the second heat dissipation plate are fixed on a substrate. The third heat dissipation plate connects the upper end parts of the first heat dissipation plate and the second heat dissipation plate into one body. A heat dissipation fin(211) effectively suppresses a temperature increase in a power source board(100). The heat dissipation fin is projected from an inner surface in order to release heat created from a semiconductor device(300). The heat dissipation fin is arranged on the inner surface of the first heat dissipation plate by being separated in a direction vertical to the surface of the power source board.
