Patent ID: 8502086

Claim:
A laminated wiring board comprising: at least one wiring board base including an insulating substrate having a first surface and a second surface opposite to the first surface, a conductive layer provided on the first surface, and a conductive via including a through-hole reaching the conductive layer from the second surface and a conductive paste filled in the through-hole, the conductive paste including a metal component forming an alloy layer with the conductive layer at an interface therebetween, wherein the conductive layer includes: a surface outside the through-hole, the surface contacting to the first surface of the insulating layer; and a smoothed portion contacting to the conductive via in the through-hole, the smoothed portion being smoother than the surface of the conductive layer contacting to the first surface of the insulating layer to increase a thickness of the alloy layer, and a maximum height roughness Rz of the smoothed portion is 3 μm or less.