A Low-Temperature Pressureless Bonding Process Using a Trimodal Mixture System of Ag Nanoparticles

A low-temperature pressureless bonding process using a mixture of trimodal-sized Ag nanoparticles was proposed to form excellent Cu-to-Cu joints. Cu-to-Cu joints formed using the mixed Ag nanoparticles at 350°C for 5 min showed bonding strength of 13.7 MPa, in spite of the bonding process without pressure. Elongated dimples observed on the fracture surface of the Cu-to-Cu joint strongly support the effect of the trimodal mixture system of Ag nanoparticles in the low-temperature pressureless bonding process.