Electronic circuit device

摘要

An electronic circuit device includes a substrate, a wiring layer formed on the surface of the substrate and essentially consisting of at least one metal selected from the group consisting of gold, copper, tin, and aluminum, a bump formed on the wiring layer and essentially consisting of at least one metal selected from the group consisting of gold, copper, and aluminum, and a micro electronic element formed on the bump, wherein solid-phase diffusion bonding is performed at least either between the wiring layer and the bump or between the bump and an electrode of the micro electronic element.