US Patent 7777348 Semiconductor device

A semiconductor device comprises a package board, a first semiconductor chip which is rectangular in shape, has a plurality of first pads arranged along its short side and is placed on the package board, and a second semiconductor chip which is rectangular in shape, has a plurality of second pads arranged along its short side and is placed on the first semiconductor chip so that a vertex of the second semiconductor chip at which its long side and its short side along which no pads are arranged meet falls on a vertex of the first semiconductor chip at which its long side and its short side along which no pads are arranged, and the long sides of the first and second semiconductor chips intersect each other.