Patent ID: 8814029

Claim:
A metal bonding method for bonding a first metal having a first oxide layer and a second metal having a second oxide layer, the first and second oxide layers each including a copper oxide as a principal component, the method comprising: filling a gap between the first oxide layer of the first metal and the second oxide layer of the second metal with a solution including copper micro-particles, oxide including the copper oxide eluting into the solution from the first and second oxide layers; pressing the first metal and the second metal against each other to reduce the gap after the gap is filled with the solution; and applying heat to the gap with the first metal and the second metal pressed against each other, wherein grains derived from the copper micro-particles remain in the gap between the first metal and the second metal during the heat applying step, and the first metal and the second metal are bonded only with copper derived from at least the copper micro-particles.