| 摘要 |
A process for promoting fluxless soldering of a mass of bulk solder having a bulk ratio of a first metal to a second metal, such as lead-enriched solder that has significantly more lead than tin. The process comprises exposing the bulk solder to energized ions of a sputtering gas in the presence of a halogen, such as fluorine, and forming a surface layer having a desired surface layer ratio of the first to the second metal that is less than the bulk ratio, the surface layer further comprising an uppermost surface film containing the fluorine or other halogen. After the solder exposure and surface-layer formation, the process may further comprise electrically joining the solder to a surface without using externally-applied flux. This process enables the joining step to be performed at less than 300° C., at approximately 180° C.
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