| 摘要: | 本研究主要探討50In-50Bi/Cu系統及In/Cu系統之界面反應，並將界面反應分為液相/固相及固相/固相反應；利用SEM觀察界面反應，以EPMA及XRD分析介金屬化合物元素組成，進而利用動力學探討界面介金屬化合物之生長行為。此外，為了解接點受熱發生界面反應對接點之影響，以推力測試探討50In-50Bi/Cu系統於不同溫度長時間熱處理對接點之機械性質影響。於50In-50Bi/Cu系統液相/固相120 °C界面反應，界面生成Cu11In9，其厚度隨迴焊時間增加而遞增，於30分鐘迴焊時，界面介金屬化合物出現分層，元素組成皆為Cu11(In,Bi)9，上層含Bi量較少而下層含Bi量較多，經動力學計算，於120 °C之50In-50Bi/Cu系統液相/固相界面反應，Cu11In9¬生成機制為擴散控制；In/Cu系統之液相/固相反應生成Cu11In9與CuIn2。
50In-50Bi/Cu系統之固相/固相反應，於熱處理溫度40 °C、60 °C、70 °C，Cu11In9-生長速率緩慢，至80 °C熱處理，Cu11In9¬厚度明顯隨時間遞增。In/Cu系統之固相/固相反應中，於50 °C以下CuIn2為穩定相，70 °C以上CuIn2¬傾向轉變為Cu11In9¬。
50In-50Bi/Cu系統之推力測試中，隨著熱處理溫度增加，接點之機械強度遞增，且脆性斷裂模式比例遞減，綜合上述，經長時間熱處理實驗，結果顯示接點之機械性質有所提升。
;This study investigates the interfacial reaction of 50In-50Bi/Cu and In/Cu. The interfacial reaction is classified into liquid-state reaction and solid-state reaction. The reaction evolution was analyzed by scanning electron microscopy to observe the microstructure, X-ray diffraction, and electron probe X-ray microanalysis to characterize the intermetallic compounds (IMCs) at the interface. Therefore, the growth behavior of IMCs is discussed through kinetics. To know the influence of solder joints during thermal processes, shear tests were carried out. In a 50In-50Bi/Cu system, an interfacial IMC, Cu11In9, was formed at 120 °C. In addition, the IMC thickness increased with reflow time. The interfacial IMC separated into two layers during 30-minutes reflow. The upper part was Cu11(In,Bi)9 which contained more Bi than the lower part of IMC. The growth mechanism of Cu11In9 in this system at 120 °C was diffusion-controlled by kinetics. In the In/Cu liquid state reaction, the interfacial IMCs are Cu11In9 and CuIn2, and the growth rate of Cu11In9 in the 50In-50Bi/Cu system was slow during 40 °C, 60 °C, and 70 °C aging processes. The thickness of the interfacial IMCs apparently increased when the aging temperature rose to 80 °C. As a result of the In/Cu solid-state reaction, CuIn2 existed as a low-temperature metastable phase under 50 °C. Moreover, CuIn2 tended to transform into Cu11In9 above 70 °C. For 50In-50Bi/Cu shear tests, the shear strength of solder joints increased with the aging time at various temperatures. In addition, the cases of brittle fracture decreased after aging. In conclusion, long-term aging could improve the mechanical properties of the 50In-50Bi/Cu system in this experiment. |
