The invention relates to a sub module of a power semiconductor device. The sub module includes a conducting assembly including a first conductor, a second conductor arranged opposite to the first conductor, a chip arranged between the first conductor and the second conductor in an overlapped manner; and a clamping assembly accommodating the conducting assembly. The clamping assembly can exert clamping forces on the first conductor and the second conductor along the overlapping direction. By using the sub module, dislocation of the chip between first conductor and the second conductor can be avoided.