PRINTED WIRING BOARD

摘要

A printed wiring board includes an insulative resin substrate having a penetrating hole, a first conductive layer formed on first surface of the substrate, a second conductive layer formed on second surface of the substrate on the opposite side, and a through-hole conductor formed in the penetrating hole and connecting the first and second conductive layers. The through-hole conductor includes a seed layer on inner wall of the penetrating hole, a first electrolytic plated layer on the seed layer such that the first plated layer is filling the space formed by the seed layer in the penetrating hole and forming recesses at the ends of the penetrating hole, respectively, and second electrolytic plated layers filling the recesses, respectively, and the second plated layers includes electrolytic plating having an average crystalline particle diameter greater than an average crystalline particle diameter of electrolytic plating forming the first plated layer.

主权项

1. A printed wiring board, comprising:
an insulative resin substrate having a penetrating hole; a first conductive layer formed on a first surface of the insulative resin substrate; a second conductive layer formed on a second surface of the insulative resin substrate on an opposite side with respect to the first surface; and a through-hole conductor formed in the penetrating hole and connecting the first conductive layer and the second conductive layer, wherein the through-hole conductor includes a seed layer formed on an inner wall of the penetrating hole, a first electrolytic plated layer formed on the seed layer such that the first electrolytic plated layer is filling a space formed by the seed layer in the penetrating hole and forming recessed portions at end portions of the penetrating hole, respectively, and a plurality of second electrolytic plated layers filling the recessed portions formed by the first electrolytic plated layer, respectively, and the second electrolytic plated layers comprise electrolytic plating having an average crystalline particle diameter which is greater than an average crystalline particle diameter of electrolytic plating forming the first electrolytic plated layer.