Patent ID: 7151319

Claim:
A semiconductor device having a semiconductor element, and a base which includes said semiconductor element mounted on the main surface thereof and external terminals provided on a surface opposite to said main surface, said base having a region where multiple grid-shaped through holes comprising a conductive member for electrically connecting the main surface and the opposing surface are disposed, wherein: said through holes includes: a signal through hole; a first power through hole of a first potential; and a second power through hole of a second potential which is lower than said first potential; said base comprises: a first through hole; a first through hole string which includes the first through hole and is disposed in a first direction; a second through hole string and a third through hole string which are disposed in said first direction each adjacent to both sides of said first through hole string; a fourth through hole string which includes said first through hole and is disposed in a second direction, different from the first direction; and a fifth through hole string and a sixth through hole string which are disposed in said second direction each adjacent to both sides of said fourth through hole string; and said base further has a through hole unit formed such that a first power through hole and a second power through hole are diagonally disposed at the through holes positioned at an intersection point of said second through hole string, said third through hole string, said fifth through hole string and said sixth through hole string.