Patent ID: 7013564

Claim:
A method of producing an electronic device by connecting a lead of a semiconductor device with an electrode of a circuit board, the semiconductor device having a lead frame structure consisting of a lead material and a single Sn—Bi alloy layer comprising 1 to 5 wt % Bi, the lead material being a lead of a lead frame, the method comprising: plating the single Sn—Bi alloy layer comprising 1 to 5 wt % Bi directly on the lead material of the lead frame, thereby forming said lead frame structure; then, directly contacting a Pb-free solder with the electrode of the circuit board and with the single Sn—Bi alloy layer on the lead; material and soldering the lead of the semiconductor device and the electrode of the circuit board by the Pb-free solder to form a compound layer between the lead material and the Pb-free solder.