Sinter bonding agent, method for producing same, and bonding method using same

The purpose of the present invention is to provide: a sinter bonding agent which is mainly composed of copper oxide nanoparticles and capable of suppressing ion migration, while having a good balance between stable dispersibility and adequate bondability in the sinter bonding agent that uses nanoparticles; a method for producing the sinter bonding agent; and a bonding method using the sinter bonding agent. This sinter bonding agent uses copper (II) oxide nanoparticles and is characterized in that: the copper (II) oxide nanoparticles each having a particle diameter of 2-50 nm (inclusive) are used as primary particles; the primary particles aggregate to form secondary particles each having a particle diameter of 3-1,000 nm (inclusive); and the secondary particles are dispersed in a solution.