A semiconductor device, including a first board, a second board having a plurality of through holes passing therethrough, and a plurality of external terminals that are respectively press-fitted into the plurality of through holes of the second board, one end portion of each external terminal passing through the corresponding through hole and being fixed to a front surface of the first board. The second board is a printed circuit board that further includes, in a top view thereof, a plurality of support regions, each having one of the plurality of through holes formed therein, and a plurality of buffer regions respectively surrounding the plurality of support regions, each buffer region having at least one buffer hole and at least one torsion portion formed therein, the at least one torsion portion being connected to the support region surrounded by each buffer region.