Wiring board, electronic device, and electronic module

Abstract

A wiring board includes an insulation substrate, a through-conductor, and a wiring conductor. The insulation substrate includes a first surface, a second surface opposite to the first surface, and a through-hole extending from the first surface to the second surface. The through-conductor is located in the through-hole and on an opening of the through-hole on a first surface side. The wiring conductor is located on the first surface and connected to the through-conductor. The through-conductor and the wiring conductor contain copper as a main component. The average size of Cu crystal grains in the through-conductor is larger than the average size of Cu crystal grains in the wiring conductor.

Dependencies are inferred from the claim text.