Abstract: A wiring board includes an insulating resin layer, wirings, and a via-hole conductor. The wirings are disposed through the insulating resin layer therebetween and formed of copper foils. The via-hole conductor penetrates through the insulating resin layer and electrically connects the wirings together. The via-hole conductor includes a resin portion and a metal portion containing copper, tin, and bismuth. The metal portion includes a first metal region including a link of copper particles, a second metal region including, as a main component, at least one of tin, a tin-copper alloy, and a tin-copper intermetallic compound, and a third metal region including bismuth as a main component. The copper particles partially include a plane-to-plane contact with a roughened surface of the copper foil, and the second metal region is partially formed on a surface of the link and on the roughened surface of the copper foil.

Abstract: In a multilayer wiring board having a wiring layer, a pad, an insulating layer provided between the wiring layer and the pad, and a plurality of connecting vias provided on the insulating layer and connecting the wiring layer to the pad, the connecting vias are provided on a peripheral edge of the pad.