Provided are a bonded structure by a lead-free solder and an electronic
article comprising the bonded structure. The bonded structure has a stable bonding
interface with respect to a change in process of time, an enough strength and resistance
to occurrence of whiskers while keeping good wettability of the solder. In the
bonded structure, a lead-free Sn—Ag—Bi alloy solder is applied to an
electrode through an Sn—Bi alloy layer. The Sn—Bi alloy, preferably,
comprises 1 to 20 wt % Bi in order to obtain good wettability of the solder. In
order to obtain desirable bonding characteristics having higher reliability in
the invention, a copper layer is provided under the Sn—Bi alloy layer thereby
obtaining an enough bonding strength.