摘要 |
A method of producing an electronic device by connecting a lead of a semiconductor device with an electrode of a circuit board to form a bonded structure. 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.
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