Damage Control of Soldering Iron Tip for Lead-Free Solder

摘要

Recently the high reaction rate of metals with lead-free solders such as copper and iron has been pointed out and becomes serious problem for manufacturing facilities. Especially the soldering-iron tip has been seriously damaged by molten lead-free solder during manual soldering. The tip is usually protected by plated iron to prevent the direct contact of copper with molten solders and, however, the lifetime of the soldering-iron tip is reduced by the heavy dissolution of plated iron in contact with molten lead-free solder. In this study the reaction test between lead-free solder and plated iron and the immersion test of iron wire into lead-free solder were performed to understand the reaction between lead-free solder and iron and to reduce the damage of soldering iron tip by molten lead free solder. As a result, it was found that the grain size of plated surface seemed to affect the dissolution thickness of the plated iron and the dissolution thickness tended to decrease with the increase of average grain size. And then the small addition of iron in lead-free solder was found to be effective for the reduction of dissolution rate of iron.