隨著先進電子構裝的技術提升，由於多層堆疊的結構中內含有各種不同性質的材料，高溫製程容易造成晶片翹曲及長期可靠度的問題，Sn-58Bi銲料之熔點為138度、具有好的抗潛變能力。濕潤性質對於迴焊是非常重要的，所以本實驗選用助焊劑含鹵素及不含鹵素之Sn-58Bi銲料及不含鹵素之Sn-56Bi1Ag0.2C銲料探討其在銅基板上於不同迴焊溫度及時間的濕潤性質。 從TG-DTA結果發現，有無鹵素對銲料熔點並無影響，然而添加銅銀之後銲料熔點下降了一度，含鹵素之SnBi銲料之接觸角不論時間長短或迴焊時間長短都大於18度，說明溫度對於該銲料濕潤性質影響不大，然而不含鹵素的SnBi銲料接觸角都比含鹵素銲料低，說明其濕潤性質較好。從前面的熱分析結果發現，在到達熔點後其熱重損失率有鹵素銲料為無鹵素銲料的兩倍多，代表助焊劑在迴焊過程中快速的揮發，來不及保護銲料及基板被氧化，造成濕潤性質下降，另外再添加了銀銅的SnBi銲料因為銀具有良好的抗氧化性，使銲料之接觸角降低，同時使濕潤性質變好。 ;With advancements in advanced electronic packaging technologies, the inclusion of various materials with different properties in multilayer stack structures poses challenges such as chip warpage and long-term reliability issues when subjected to high-temperature processes. Sn-58Bi solder, with a melting point of 138°C, exhibits excellent resistance to creep deformation. Wetting property is crucial during reflow, thus in this experiment, both halogen-containing and halogen-free Sn-Bi solder, as well as halogen-free Sn-56Bi1Ag0.2C solder, were selected to investigate their wetting characteristics on copper substrates at different reflow temperatures and times. From the TG-DTA results, it was observed that the addition of halogens had no impact on the solder′s melting point. The addition of copper-silver to the solder resulted in a one-degree decrease in the melting point. For the halogen-containing SnBi solder, the contact angle was consistently above 18 degrees. This indicates that temperature had minimal effect on the wetting property . On the other hand, the halogen-free solder exhibited lower contact angles compared to the halogen-containing solder, indicating better wetting characteristics. The thermal analysis results showed that the halogen-containing solder had a rapidly weight loss rate after reaching the melting point. This suggests that the flux in the halogen-containing solder evaporated rapidly during the reflow process, possibly leading to insufficient protection of the solder and substrate from oxidation, resulting in a decrease in wetting property. The addition of silver and copper to the SnBi solder improved wetting characteristics, as silver possesses excellent antioxidation properties, leading to better wetting properties.
