Abstract: Provided is a composition for metal bonding, especially a bonding composition containing metal particles, which is capable of achieving high bonding strength by bonding at a relatively low temperature without the application of a pressure, and which has heat resistance and is thus not susceptible to decrease in the bonding strength due to decomposition or deterioration of a resin component when the service temperature thereof is increased. A bonding composition which is characterized by containing two or more kinds of metal particles having different average particle diameters, an organic component and a dispersant, and which is also characterized in that the particle diameter ratio of the average particle diameter (DS) of metal particles (S) that have the smallest average particle diameter to the average particle diameter (DL) of metal particles (L) that have the largest average particle diameter, namely DS/DL is from 1×10-4 to 0.5.

Abstract: Provided is a composition for bonding, in particular, a composition for bonding which contains metal particles, said composition for bonding enabling the achievement of high bonding strength by bonding at a relatively low temperature and having such heat resistance that a decrease in the bonding strength does not easily occur due to &composition, deterioration or the like of a resin component when service temperature is increased. This composition for bonding is characterized by containing inorganic particles and an organic material that contains an amine and/or a carboxylic acid and adheres to at least a part of the surface of each inorganic particle, and is also characterized in that the weight loss rate when heated from room temperature to 200°c. is 33-69% and the weight loss rate when heated from 200° c. to 300° c. is 24-50% as determined by thermal analysis.