| 摘要 |
<p>An object of the present invention is to provide solder in which bridges rarely occur. Solder having a solid phase temperature and a liquid phase temperature different from each other is used. Since such solder is not wholly melted immediately after it starts being melted (immediately after it attains the solid phase temperature), the surface tension thereof is apparently low. Therefore, the solder is hard to be moved in the bridge-forming direction (leads-striding direction). In the meantime, the solder wet-spreads over a pad and leads owing to its wet-spreading force even immediately after it starts being melted. Accordingly, the occurrence of bridges can be prevented. Even when solder which has been supplied in advance is already in a bridged state, the bridge-forming solder is separated uniformly as it wet-spreads over leads, so that the bridges disappear.</p> |
