Disclosed herein is a power module package including: a first heat dissipation plate including a first flow path, a second flow path, and a third flow path which are sequentially formed, the first flow path and the third flow path being formed to have a step therebetween; and a second heat dissipation plate formed under the first heat dissipation plate, having one face and the other face, having a semiconductor device mounting groove formed in the one face thereof, and including a fourth flow path having one end connected to the second flow path and the other end connected to the third flow path, wherein a cooling material introduced through the first flow path is distributed to the third flow path and the fourth flow path based on the second flow path.