热浸镀锡电子铜带材回流焊过程中镀锡层的微观结构及缺陷分析  

Microstructure and defect analysis of tin coating of hot-dip tin-plated electronic copper strip during reflow soldering

作　　者：欧阳豫鲁 张国赏 柳亚辉 朱倩倩 宋克兴 皇涛[1] 张彦敏[1] 刘栋 OUYANG Yu-lu;ZHANG Guo-shang;LIU Ya-hui;ZHU Qian-qian;SONG Ke-xing;HUANG Tao;ZHANG Yan-min;LIU Dong(School of Material Science and Engineering,Henan University of Science and Technology,Luoyang 471023,China;Institute of Materials,Henan Academy of Sciences,Zhengzhou 450002,China;School of Mechatronics Engineering,Henan University of Science and Technology,Luoyang 471023,China;KMD Precise Copper Strip(Henan)Co Ltd,Xinxiang 453000,China)

机构地区：[1]河南科技大学材料科学与工程学院,河南洛阳471023 [2]河南省科学院材料研究所,河南郑州450002 [3]河南科技大学机电工程学院,河南洛阳471023 [4]凯美龙精密铜板带(河南)有限公司,河南新乡453000

出　　处：《材料热处理学报》2024年第7期184-193,共10页Transactions of Materials and Heat Treatment

基　　金：河南省科技研发计划联合基金(231111231700);河南省重点研发与推广专项(科技攻关)(21011914)。

摘　　要：热浸镀锡电子铜带材是高端连接器和PCB(Printed circuit board)所需的关键导体材料,该材料在回流焊过程中产生的缺陷严重影响其服役性能。采用扫描电镜(SEM)、能谱仪(EDS)对热浸镀锡铜带材回流焊过程中缺陷组织类型及分布形态进行表征,并对回流焊锡珠样品、回流焊非正常样品和回流焊正常样品的表层形貌进行对比。结果表明:回流焊过程中,样品镀层中均产生了不同程度的孔洞缺陷,孔洞尺寸在0.2~36μm,孔洞的产生与基体合金类型、基体合金厚度和镀层厚度无明显关联;孔洞形态并不一致,发现了孔洞边缘呈现出立体网状结构、边缘参差不齐、孔洞中存在小颗粒的现象。回流焊过程中,镀锡层中Cu、Sn元素发生了重新分布,不同缺陷所造成的元素分布情况并不相同。镀层结构中,化合物层、多相界面间高低起伏与镀层表面高度起伏无明显关联。Hot-dip tin-plated electronic copper strip is a key conductor material for high-end connectors and PCB(Printed circuit board),and the defects generated during reflow soldering seriously affect its service performance.Scanning electron microscopy(SEM) and energy dispersive spectroscopy(EDS) were used to characterize the types and distribution morphology of defects in the hot-dip tin-plated copper strip during reflow soldering.The surface morphology of reflow soldering solder bead samples,abnormal reflow soldering samples and normal reflow soldering samples was compared.The results show that during the reflow soldering,there are varying degrees of hole defects in the sample coating,with the hole sizes ranging from 0.2 to 36 μm.There is no obvious correlation between the formation of holes and the type of substrate alloy,the thickness of substrate alloy and the thickness of coating.The morphology of the holes is not consistent,and it is found that the edges of the holes exhibit a three-dimensional network structure,with uneven edges and the presence of small particles in the holes.During the reflow soldering,Cu and Sn elements in the tin plating layer are redistributed,and the distribution of elements caused by different defects is not the same.In the coating structure,there is no significant correlation between the height fluctuations of the compound layer and multiphase interface and the surface height fluctuations of the coating.

关 键 词：热浸镀锡 回流焊 铜带材 镀层缺陷 锡珠 

分 类 号：TG174.44[金属学及工艺—金属表面处理]