Patent ID: 9741647
Date: 2017-08-22
CPC Classifications: H01L

Claim:
1. A wiring substrate comprising: a first wiring layer including a first land; a first insulative layer formed on the first wiring layer; a second wiring layer formed on the first insulative layer; a second insulative layer formed on the second wiring layer; and a via filled in a via hole, the via hole being formed continuously penetrating completely through both the first insulative layer and the second insulative layer in a thicknesswise direction to expose the first land of the first wiring layer, wherein the via is a landless via, wherein the landless via includes a lower end face, which is supported by and electrically connected to the first land of the first wiring layer, and an upper end face, which is located opposed to the lower end face and exposed from an upper surface of the second insulative layer, the upper end face of the landless via serves as a semiconductor chip connection pad to which one of a plurality of bump electrodes arranged on a circuit formation surface of a semiconductor chip is directly and electrically flip-chip connected, the landless via is one of a plurality of landless vias that are arranged in a grid in at least a central portion of a mounting region in which the semiconductor chip is mounted on the wiring substrate, the second wiring layer includes a coupling portion projecting into the via hole to be electrically and directly connected to the landless via, wherein the coupling portion of the second wiring layer is an end of the second wiring layer, a wiring width of the coupling portion of the second wiring layer is smaller than a diameter of the landless via in a plan view, and a wiring length of the coupling portion which is electrically connected to the landless via is smaller than the diameter of the landless via in the plan view, and the landless via is filled into the via hole to cover a wall of the via hole, the first land exposed in the via hole, and the coupling portion projecting into the via hole.