| Summary: | 碩士 === 國立交通大學 === 工學院半導體材料與製程產業專班 === 96 === In order to study the effect of the addition of Co to the Sn-0.7Cu solder, the formation of an IMC at the interface between Sn-0.7Cu-xCo(x=0, 0.05, 0.1wt%) solders and Cu Substrate were investigated, and the joint strength was also evaluated by tensile test.
From the DSC analysis of Sn-0.7Cu alloys containing various amounts of Co, it was found that the eutectic reaction occurred around 227.3°C. The microstructure of Sn-0.7Cu solder was identified asβ-Sn plus eutectic (β-Sn+Cu6Sn5) by SEM and EDS. Sn-Cu-Co compounds can be found in Sn-0.7Cu solder with 0.05wt%Co. Sn2Co IMCs can be observed in Sn-0.7Cu solder with 0.1wt%Co. Additionally, the results of the tensile test show that the addition of Co elements can improve the mechanical properties of the solder.
After high temperature storage test at 150℃, the growth of interfacial Cu3Sn IMCs was inhibited by the adding of Co into the Sn-0.7Cu solder. The addition of Co elements can improve the joint strength of the solder joints.
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