Abstract: The joined structure of the present invention is a joined structure in which a substrate having a circuit pattern and a member to be joined including an electrode terminal are joined together via a conductive joining material. When a contact area between the circuit pattern and the conductive joining material is defined as X, a contact area between the electrode terminal and the conductive joining material is defined as Y, and a thermal conductivity of the conductive joining material is defined as ?, the joined structure satisfies the following Formula (1), SQRT(X)/SQRT(Y)?2.9209×??0.141??(1).

Abstract: The present invention is directed to an Sn—Ag—Cu-based solder powder which comprises solder powder having an average particle size of 5 ?m or less, and a dried material of a solution of hydroxybenzoic acid or an ester thereof having a melting point of 250° C. or lower being attached onto a surface of the solder powder as an additive, wherein the additive is preferably salicylic acid, ethyl 3,4-dihydroxybenzoate or ethyl 3,5-dihydroxybenzoate, an attached amount of the additive is preferably 0.01 to 1.0 part by mass based on 100 parts by mass of the total amount of the components of tin, silver and copper contained in the solder powder, a content of the silver is 0.1 to 10% by mass when the total amount of the components of tin, silver and copper is made 100% by mass, a content of the copper is 0.1 to 2.0% by mass when the total amount of the components of tin, silver and copper is made 100% by mass, and a remainder being tin.