Metal-Metal Bonding Properties of Copper Oxide Nanoparticles

The present study performs production of copper oxide particles, and examines the particles as a filler in metal metal bonding. Leaf-like aggregates with a longitudinal size of ca. 600-950 nm and a lateral size of ca. 280-380 nm, which were composed of particles with a size of ca. 10 nm, were produced with a salt-base reaction using a Cu(NO3)(2) aqueous solution and an NaOH aqueous solution. Copper discs were bonded by pressurizing them, between which the particles were sandwiched, at 1.2 MPa for 5 min in H2 gas under annealing at 400 degrees C. Bonding properties of particles were evaluated by measuring shear strength, which was required to separate the discs. The shear strengths were as large as ca. 23 MPa at NaOH/Cu(NO3)(2) ratios of 1.9 and 2.0, since CuO particles that contained nether Cu2(OH)(3)NO3 nor impurity based on the addition of NaOH were produced at the ratios.