SEMICONDUCTOR DEVICE AND MOUNTING STRUCTURE

PROBLEM TO BE SOLVED: To reduce the capacitive components of leads and pads for high-speed signal and to improve the transmission quality of the high-speed signal, in a semiconductor device and its mounting structure having a plurality of surface-mounting leads. SOLUTION: The semiconductor device 10 includes a plurality of surface-mounting leads 20, and each of the leads 20 has a joint surface to be jointed to a wiring substrate 30 when the semiconductor device 10 is mounted onto the wiring substrate 30. The lead 20 includes a first lead 22 for a predetermined high-speed signal, and a second lead 21 for other utility. The joint surface of the first lead 21 is smaller than that of the second lead 21. The wiring substrate 30 has a plurality of mounting pads 40 as positionally corresponding to the joint surface of a plurality of leads 20 in the semiconductor device 10. A plurality of pads 40 in the wiring substrate 30 include a first pad 42 jointed to the first lead 22 and a second pad 41 jointed to the second lead 21, and the area of the first pad 42 is smaller than that of the second pad 41. COPYRIGHT: (C)2011,JPO&INPIT