| 摘要 |
<p><P>PROBLEM TO BE SOLVED: To provide a soldering method for works which prevents generation of Kirkendall voids despite the use of a zinc-based lead-free solder, thus exerts high reliability, and allows a soldering mounter to have a long life, and to provide the soldering mounter. <P>SOLUTION: The component of solder bumps 3 of a flip chip 1 is Sn-3Ag-0.5Cu, i.e. a non zinc-based second lead-free solder without comprising zinc. The component of solder portions 6 on copper electrodes 5 of a circuit board 4 is Sn-8Zn-3Bi comprising zinc by 8%, i.e. a zinc-based first lead-free solder. The flip chip 1 is mounted on the circuit board 4, followed by heating to melt the solder bumps 3 and the solder portions 6, whereby solder connecting portions 7 of a third lead-free solder are formed. The weight percentage of zinc in the solder connecting portions 7 produced by heating and melting has thus been reduced from the initial 8% to 2% or below. In this way, damages caused by zinc (generation of Kirkendall voids) is eliminated and a long life of the soldering mounter is ensured. <P>COPYRIGHT: (C)2004,JPO</p> |
