Patent ID: 9668361
Date: 2017-05-30
CPC Classifications: H05K

Claim:
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 of the insulative resin substrate; and a through-hole conductor formed in the penetrating hole of the insulative resin substrate such that the through-hole conductor is connecting the first conductive layer and the second conductive layer, wherein the through-hole conductor comprises a seed layer formed on an inner wall of the penetrating hole, a laminated electrolytic plated layer formed on the seed layer and a filled electrolytic plated layer formed on the laminated electrolytic plated layer, the laminated electrolytic plated layer is formed in the penetrating hole such that the laminated electrolytic plated layer is closing a center portion of the penetrating hole and forming a recessed portion at an end portion of the penetrating hole, the filled electrolytic plated layer is formed in the penetrating hole such that the filled electrolytic plated layer is filling the recessed portion of the penetrating hole, the laminated electrolytic plated layer comprises a plurality of electrolytic plated films such that the electrolytic plated films are laminated along the seed layer and that each of the electrolytic plated films has a thickness which is less at an edge portion than at a center portion, and the filled electrolytic plated layer comprises electrolytic plated crystalline particles having a particle diameter which is greater than a particle diameter of electrolytic plated crystalline particles of the laminated electrolytic plated layer.