Abstract:
In order to study the mechanism of vacuum fluxless soldering on
the conditions of laser heating, the method of measuring
temperature by the thermocouple is used to analyze the spreading
and wetting process of both fluxless Sn-Pb solder in the vacuum
surroundings and flux Sn-Pb solder on Cu pad. Solder spreading
and wetting affected by the soldering thermal process is also
discussed according to the thermodynamics principle. Results show
that vacuum fluxless soldering demands higher temperature, and
the fall of the solder surface tension is the important factor
achieving fluxless laser soldering.
Key words: Fluxless
soldering Soldering thermal process Spreading and wetting
*
This project
is supported by National Natural Science Foundation of China. Manuscript received on
March 25, 1999; revised manuscript July 15, 1999
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