Patent ID: 8399779
Filing Date: 2013-03-19
Classification: H01L,H05K,Y10T

Abstract:
1. A wiring board including a pad exposed from an opening portion of an outermost insulating layer, the pad comprising: a first metal layer having a surface that is exposed from the wiring board; a second metal layer provided on the first metal layer and formed of a material effective in preventing a metal contained in a via inside the board from diffusing into the first metal layer; and a third metal layer provided between the second metal layer and the via, and in direct contact with both the second metal layer and the via, and formed of a material harder to be oxidized than that of the second metal layer, wherein a thickness of the third metal layer is greater than that of the other metal layers, wherein a side surface of the third metal layer and a surface of the third metal layer to which the via is to be connected are roughed, and wherein a surface arranged on the third metal layer side of the pad and a side surface of the pad contact an outermost insulating layer.