Abstract: Provided is a copper-based paste capable of bonding a chip component and a substrate more firmly and obtaining a copper-based bonding material having high thermal conductivity. This copper oxide paste includes copper-containing particles, a binder resin, and an organic solvent. The copper-containing particles contain Cu2O and CuO. The total amount of copper element constituting Cu2O and copper element constituting CuO is 90% or more of the copper element contained in the copper-containing particles. The copper-containing particles have a 50% cumulative particle size (D50) of 0.20-5.0 ?m inclusive; the 50% cumulative particle size (D50) and the 10% cumulative particle size (D10) satisfy 1.3?D50/D10?4.9; the 50% cumulative particle size (D50) and the 90% cumulative particle size (D90) satisfy 1.2?D90/D50?3.7, and the BET specific surface area of the copper-containing particles is 1.0 m2/g to 8.0 m2/g inclusive.

Abstract: This conductive paste is such that the printing properties and sintering properties are superior and is formed such that resistance of wiring after sintering is lowered. This conductive paste is characterized by being formed from copper-based metal particles and by an aspect ratio (dmax/dmin), which is defined as the ratio of the maximum diameter (dmax) and minimum diameter (dmin) for the metal particles, being greater than or equal to 1.0 and smaller than 2.2.

Abstract: This conductive paste is such that the printing properties and sintering properties are superior and is formed such that resistance of wiring after sintering is lowered. This conductive paste is characterized by being formed from copper-based metal particles and by an aspect ratio (dmax/dmin), which is defined as the ratio of the maximum diameter (dmax) and minimum diameter (dmin) for the metal particles, being greater than or equal to 1.0 and smaller than 2.2.