| 摘要 |
The melting of die-bonding solder material is prevented even when soldering a surface-mount component formed using the die-bonding solder material on a printed circuit board using a mounting solder material. The surface-mount component formed using (Sn-Sb)-based solder material having high melting point as the solder material 30 for die pad, the (Sn-Sb)-based solder material containing Cu not more than a predetermined quantity of Cu constituent and a main ingredient thereof being Sn, is soldered on a board terminal portion of a circuit board using (Sn-Ag-Cu-Bi)-based solder material as the mounting solder material 70 with the solder material being applied on the terminal portion. Since solidus temperature of the die-bonding solder material 30 is 243 degrees C. and liquidus temperature of the mounting solder material 70 is about 215 through 220 degrees C., the melting of die-bonding solder material 30 is prevented even at the heating temperature (240 degrees C. or less) of a reflow furnace. |
