| Summary: | 碩士 === 國立勤益科技大學 === 機械工程系 === 100 === The rise of environmental awareness in recent years, the European Union to limit the content of lead in electrical and electronic products and electronic equipment welding materials are mostly tin-lead alloy, so only when the research and development of lead-free solder. In electronic packaging, the solder alloy for bonding electronic components and the substrate, so the joint density and strength has become a very important nature; the strength of the density of the solder alloy and substrate because the reaction of the substrate between the atom and the solder intermetallic compounds , and the wetting effect, but if generating excessive intermetallic compounds, will go to the wetting phenomenon, and therefore control over the material in need of appropriate in order to achieve good wetting.
This study investigated the wetting behavior of lead-free solders of the tin-silver-bismuth zinc and metallurgical structure of the experiment the proportion of different components of lead-free solder of Sn-Ag-Bi-Zn compared The thermal properties of the solder alloy by the analysis, adding zinc can effectively reduce the Sn-13wt. %Ag-14wt. %Bi solder alloy melting point of Sn-13wt. %Ag-14wt. %Bi-15wt. %Zn alloy solid / liquid line temperature of 188 ℃ and 196 ℃, closest to the traditional tin lead alloy solder (Sn-37wt. %Pb) melting point (183 ° C).
Sn-13Ag-14Bi-15wt. %Zn in the microstructure of hypereutectic Structure AgZn3 compounds. Add Zn to contribute to the precipitation of the Ag phase, enable the primary Ag phase coarsening. When added to the 1~5wt. % Zn in the SnAg alloy, SnAg alloy substrate by the hypoeutectic to like eutectic. When the Zn Add to 7wt. % in SnAg alloy formation SnZn compounds.
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