JOINING STRUCTURE AND ELECTRONIC MEMBER-JOINING STRUCTURAL BODY

摘要

Provided is a joining structure that prevents the occurrence of cracks at a joined section of a metal member and a metal porous body and that makes it possible to achieve a highly reliable joint. This joining structure comprises a metal member (1) and a metal porous body (2) that is formed on the metal member (1). The metal member (1) comprises: an external layer (1b) that includes a main surface (1a) and that is formed on the metal porous body (2) side; and an internal layer (1c) that is formed at a position that is separated from the metal porous body (2) by a greater distance than the external layer (1b) in the thickness direction. The average crystal grain size (ds) of the external layer (1b) is smaller than the average crystal grain size (di) of the internal layer (1c). The average crystal grain size (dp) of the metal porous body (2) is smaller than or equal to the average crystal grain size (ds) of the external layer (1b).