To provide a wiring substrate for mounting semiconductor which is effective for the high integration of a semiconductor device, high speed, or increase in terminal by multifunctionalities, and the narrow pitch of a distance between terminals, in which the semiconductor device can be mounted at high density and high accuracy, specifically on both the surfaces of a substrate, and which is superior also in reliability. 半導体デバイスの高集積化、高速化又は多機能化による端子の増加及び端子間隔の狭ピッチ化に有効であり、半導体デバイスを特に基板両面に高密度かつ高精度に搭載でき、更に信頼性にも優れた半導体搭載用配線基板を提供する。 - 特許庁