abstract |
Through holes 36 are formed to penetrate a core substraten30 and lower interlayer resin insulating layers 50, and via holesn66 are formed right on the through holes 36, respectively. Duento this, the through holes 36 and the via holes 66 are arrangednlinearly, thereby making it possible to shorten wiring lengthnand to accelerate signal transmission speed. Also, since thenthrough holes 36 and the via holes 66 to be connected to soldernbumps 76 (conductive connection pins 78), respectively, arendirectly connected to one another, excellent reliability innconnection is ensured. |