Crack-resistant solder joint, electronic component such as circuit substrate having the solder joint, semiconductor device, and manufacturing method of electronic component

A method for manufacturing an electronic component, comprising the steps of:

• (i) forming a concave recessed in an electrode having a flat reference surface;
• (ii) forming one or more metal layers on a surface of the concave;
• and
• (iii) solder bonding the metal layer, wherein
• the metal layer is positioned higher or lower than the reference surface in the step (ii), and
• a position of an interface between (a) a tin alloy layer formed on a surface of the metal layer in solder bonding the metal layer and (b) the metal layer deviates from a plane including the reference surface in the step (iii).

A method for manufacturing an electronic component, comprising the steps of:

• (i) forming a concave recessed in an electrode having a flat reference surface;
• (ii) forming one or more metal layers on a surface of the concave;
• and
• (iii) solder bonding the metal layer, wherein
• a first metal layer is provided on the surface of the concave so as to be positioned higher or lower than the reference surface and a second metal layer is further provided in the step (ii), and
• a position of an interface between the first metal layer and the second metal layer deviates from a plane including the reference surface in the step (iii).