SEMICONDUCTOR APPARATUS

PROBLEM TO BE SOLVED: To improve a guarantee for long-term reliability in a semiconductor apparatus loading a plurality of semiconductor devices on a mounting substrate. SOLUTION: The mounting substrate has connecting wiring (50) connecting a data input-output terminal (10c) for the first semiconductor device (3) and the data input-output terminal (11d) for the second semiconductor device (4), and has branch wiring (51) to a test terminal (12t) from an intermediate section. The place (52) of a branch is positioned near the terminal (11d) having large output drive. When the mounting substrate has the branch in the intermediate section of the wiring, the impedance of the wiring from one device terminal is made lower than that of one path by a voltage-dividing effect by the branch of the path. The degree of the reduction of the impedance from the device terminals is increased as progressing to the branch. Since the place of the branch has a larger drive capacity in, a signal outputted from the device terminal having a large drive capacity is increased in the degree of the relaxation of an overshoot and an undershoot. COPYRIGHT: (C)2006,JPO&NCIPI