【摘要】 采用润湿平衡测试方法，通过施加直流电，研究了温度为250℃时，液态Sn钎料在Cu基体上的润湿行为，并分析了平衡润湿曲线和界面析出金属间化合物（IMC）形貌。结果表明，施加直流电作用对润湿性和IMC有显著的影响。随着电流的增大，平衡润湿力和IMC层的厚度增加。电流的极性对平衡润湿力和IMC层的厚度也有一定的影响，当电流为负时，最终的平衡润湿力和IMC层的厚度明显高于电流为正。液态Sn钎料在Cu基体上铺展过程中，界面反应析出的IMC为三相线的移动提供了化学驱动力，而施加直电流作用，增加了界面原子的相互作用，加速了化学反应，促进了润湿性；同时，电流作用引起液态Sn钎料内部产生Marangoni对流，从而改变了三相线的结构，为液态Sn钎料在Cu基体上的铺展提供了物理驱动力。更多还原

【Abstract】 The wetting behavior of liquid tin（Sn） solder on copper（Cu） substrate at 250 ℃ was investigated by the wetting balance method under the action of direct current（DC）. The curves of wetting balance were measured and the morphology of the intermetallic compound（IMC） precipitated at the interface were observed. Results show that DC has a significant effect on the wettability and IMC. As the current increases, the balance wetting force and the thickness of the IMC layer increase. The direction of the DC also has a certain effect on the balance wetting force and IMC layer. When the current is negative, the final balance wetting force and the thickness of the Cu₆Sn₅ layer are significantly higher than those in the positive current case, which is attributed to electromigration.The IMC precipitation at the interface provides a chemical driving force for the movement of the triple junction. The interaction of the interface atoms and the chemical reaction are enhanced by DC, thereby improving wettability. Meanwhile, the Marangoni convection caused by DC inside liquid Sn solder changes the structure of triple junction, which provides a physical driving force for the spread of the liquid Sn solder on the Cu substrate.更多还原