Abstract: A resistance welding method according to the invention includes: a melting start time specification process for specifying a melting start time, which is a time at which at least a part of a welding portion of a welding subject starts to melt while being subjected to Joule heating by a power input from an electrode pressed against the welding subject, by detecting a variation in an ultrasonic wave emitted toward the welding portion; a first power amount calculation process for calculating a first power amount, which is an integrated value of the power input into the welding subject via the electrode from the melting start time; a first determination process for determining whether or not the first power amount has reached a first set value; and a heating process for performing the Joule heating from the melting start time until the first power amount reaches the first set value.

Abstract: Provided is a composite nanometal paste which, when a layer of the paste interposed between upper and lower bodies is sintered in an inert gas under no load until the layer turns to a metal layer, attains a shear bond strength between the upper and lower bodies of 10 MPa or higher. The composite nanometal paste contains, as metallic components, composite metallic nanoparticles comprising metal cores with an average particle diameter of X (nm) and an organic coating layer formed around the circumference, metallic nanofiller particles having an average particle diameter of d (nm), and metallic filler particles having an average particle diameter of D (nm), and satisfies the first relation X<d<D and the second relation X<d<100 (nm).

Abstract: Provided is a composite nanometal paste which, when a layer of the paste interposed between upper and lower bodies is sintered in an inert gas under no load until the layer turns to a metal layer, attains a shear bond strength between the upper and lower bodies of 10 MPa or higher. The composite nanometal paste contains, as metallic components, composite metallic nanoparticles comprising metal cores with an average particle diameter of X (nm) and an organic coating layer formed around the circumference, metallic nanofiller particles having an average particle diameter of d (nm), and metallic filler particles having an average particle diameter of D (nm), and satisfies the first relation X<d<D and the second relation X<d<100 (nm).