Copper paste for joining, method for joining body to be joined, method for producing joined body, and method for producing copper paste for joining

Abstract

A copper paste for joining is provided that is unlikely to generate voids in a sintering process of a coating film formed thereof to achieve a sufficiently high joining rate to a target member to be joined. The copper paste for joining contains: two or more copper powders having different particle sizes; and a solvent; wherein one of the copper powders has an increase rate of a crystallite size, (D2−D1)/D1×100, of 5% or more, where D1 (nm) represents a crystallite size at 150° C. and D2 (nm) represents a crystallite size at 250° C.; the solvent has a boiling point of 150° C. or higher and lower than 300° C.; and the proportion of the total amount of the copper powders is 88 mass % or more in 100 mass % of the copper paste.

Dependencies are inferred from the claim text.