| abstract |
A multilayer wiring board having via-hole conductors which electrically connects a plurality of wirings arranged in a manner such that an insulating resin layer is placed between the wirings, wherein: the via-hole conductors each include copper, tin, and bismuth, namely, a first metal region including a link of copper particles in plane-to-plane contact with one another, the link electrically connecting the wirings, a second metal region mainly composed of one or more of tin, a tin-copper alloy, and a tin-copper intermetallic compound, and a third metal region mainly composed of bismuth; at least a part of the second metal region is in contact with the surface of the copper particles, the surface excluding the area of the plane-to-plane contact portion of the link; and the Cu, Sn, and Bi in the metal portion are of a composition having a specific weight ratio (Cu:Sn:Bi). |