A copper paste for pressureless bonding is a copper paste for pressureless bonding, containing: metal particles; and a dispersion medium, in which the metal particles include sub-micro copper particles having a volume average particle diameter of greater than or equal to 0.01 m and less than or equal to 0.8 m, and micro copper particles having a volume average particle diameter of greater than or equal to 2.0 m and less than or equal to 50 m, and the dispersion medium contains a solvent having a boiling point of higher than or equal to 300 C., and a content of the solvent having a boiling point of higher than or equal to 300 C. is greater than or equal to 2 mass % on the basis of a total mass of the copper paste for pressureless bonding.

A copper paste for pressureless bonding is a copper paste for pressureless bonding, containing: metal particles; and a dispersion medium, in which the metal particles include sub-micro copper particles having a volume average particle diameter of greater than or equal to 0.01 m and less than or equal to 0.8 m, and micro copper particles having a volume average particle diameter of greater than or equal to 2.0 m and less than or equal to 50 m, and the dispersion medium contains a solvent having a boiling point of higher than or equal to 300 C., and a content of the solvent having a boiling point of higher than or equal to 300 C. is greater than or equal to 2 mass % on the basis of a total mass of the copper paste for pressureless bonding.

Disclosed is a method for transient liquid-phase bonding between metal materials using a magnetic force. In particular, in the method, a magnetic force is applied to a transient liquid-phase bonding process, thereby shortening a transient liquid-phase bonding time between the metal materials, and obtaining high bonding strength. To this end, an attractive magnetic force is applied to a ferromagnetic base while a repulsive magnetic force is applied to a diamagnetic base, thereby to accelerate diffusion. This may reduce a bonding time during a transient liquid-phase bonding process between two bases and suppress formation of Kirkendall voids and voids and suppress a layered structure of an intermetallic compound, thereby to increase a bonding strength.

Disclosed is a method for transient liquid-phase bonding between metal materials using a magnetic force. In particular, in the method, a magnetic force is applied to a transient liquid-phase bonding process, thereby shortening a transient liquid-phase bonding time between the metal materials, and obtaining high bonding strength. To this end, an attractive magnetic force is applied to a ferromagnetic base while a repulsive magnetic force is applied to a diamagnetic base, thereby to accelerate diffusion. This may reduce a bonding time during a transient liquid-phase bonding process between two bases and suppress formation of Kirkendall voids and voids and suppress a layered structure of an intermetallic compound, thereby to increase a bonding strength.

Provided is a metal paste for joints, containing: metal particles; and linear or branched monovalent aliphatic alcohol having 1 to 20 carbon atoms, in which the metal particles include sub-micro copper particles having a volume average particle diameter of 0.12 m to 0.8 M.

Provided is a metal paste for joints, containing: metal particles; and linear or branched monovalent aliphatic alcohol having 1 to 20 carbon atoms, in which the metal particles include sub-micro copper particles having a volume average particle diameter of 0.12 m to 0.8 M.

An embodiment of the present invention provides a method for producing a bonded object. The method comprises a step for preparing a laminate in which a first member, a copper bonding paste, and a second member are laminated in order and a step for sintering the copper bonding paste under a pressure of 0.1-1 MPa. The copper bonding paste contains metal particles and a dispersion medium, wherein the content of metal particles is at 50 mass % or more with respect to the total mass of the copper bonding paste, and the metal particles contain 95 mass % or more of submicro copper particles with respect to the total mass of the metal particles.

An embodiment of the present invention provides a method for producing a bonded object. The method comprises a step for preparing a laminate in which a first member, a copper bonding paste, and a second member are laminated in order and a step for sintering the copper bonding paste under a pressure of 0.1-1 MPa. The copper bonding paste contains metal particles and a dispersion medium, wherein the content of metal particles is at 50 mass % or more with respect to the total mass of the copper bonding paste, and the metal particles contain 95 mass % or more of submicro copper particles with respect to the total mass of the metal particles.

A copper paste for pressureless bonding is a copper paste for pressureless bonding, containing: metal particles; and a dispersion medium, in which the metal particles include sub-micro copper particles having a volume average particle diameter of greater than or equal to 0.01 m and less than or equal to 0.8 m, and micro copper particles having a volume average particle diameter of greater than or equal to 2.0 m and less than or equal to 50 m, and the dispersion medium contains a solvent having a boiling point of higher than or equal to 300 C., and a content of the solvent having a boiling point of higher than or equal to 300 C. is greater than or equal to 2 mass % on the basis of a total mass of the copper paste for pressureless bonding.

A copper paste for pressureless bonding is a copper paste for pressureless bonding, containing: metal particles; and a dispersion medium, in which the metal particles include sub-micro copper particles having a volume average particle diameter of greater than or equal to 0.01 m and less than or equal to 0.8 m, and micro copper particles having a volume average particle diameter of greater than or equal to 2.0 m and less than or equal to 50 m, and the dispersion medium contains a solvent having a boiling point of higher than or equal to 300 C., and a content of the solvent having a boiling point of higher than or equal to 300 C. is greater than or equal to 2 mass % on the basis of a total mass of the copper paste for pressureless bonding.