Semiconductor device.

摘要

A semiconductor device (1) having a multilayer package, provided with signal lines (212, 213, 121, 111; 213 min ) which connect a chip (7) provided at a top portion of a package with external terminals (211, 311) provided at a bottom portion of the package. The signal lines have portions (212, 213 min ) formed along side surfaces of the package. Ground surfaces (442, 452) are formed at predetermined distances on two sides of the high-speed signal lines (212, 213 min ). Coplanar waveguides are formed by the high-speed signal lines and the ground surfaces, so the impedance of vertical portions (212, 213 min ) of the high-speed signal lines is matched to the circuits connected thereto.