镍/铜箔回流焊与激光钎焊界面显微组织与性能  

Interface microstructure and properties of nickel/copper foil reflow soldering and laser soldering

作　　者：孙茜[1] 王佳乐 周兴汶 王晓南[1] SUN Qian;WANG Jiale;ZHOU Xingwen;WANG Xiaonan(Soochow University,Suzhou,215131,China)

机构地区：[1]苏州大学,苏州215021

出　　处：《焊接学报》2023年第12期35-40,I0005,共7页Transactions of The China Welding Institution

基　　金：国家自然科学基金资助项目(52005357);中国博士后面上基金项目(2022M712308);江苏省自然科学基金(BK20230497)。

摘　　要：基于镍箔“桥”替代铝铜直接焊接的背景下,利用回流焊、半导体激光钎焊对镍铜箔片进行异质连接.对比分析了接头形貌及界面显微组织的形成机制,并对其力学性能进行评价.结果表明,两种焊接接头成形良好,且无焊接缺陷产生;激光钎焊焊缝内由锡的固溶体和具有等轴晶形态的Cu-Sn金属间化合物组成,而回流焊焊缝则为锡的固溶体;两种焊接接头铜-锡、镍-锡界面均呈现不同形貌,且铜-锡界面层厚度大于镍-锡界面层.回流焊在铜-锡界面处显微组织呈扇贝状分布,其组成为铜固溶体→Cu_(3)Sn金属间化合物→Cu_(6)Sn_(5)金属间化合物;激光钎焊铜-锡界面处由多种Cu-Sn金属间化合物组成.在镍-锡界面处,回流焊呈现连续分布的(Cu,Ni)_(6)Sn_(5)金属间化合物,而激光钎焊则是由短棒状(Cu,Ni)_(3)Sn_(4)与条状(Cu,Ni)_(6)Sn_(5)组成,两种焊接接头最大剪切力可达320 N以上,远高于实际生产要求.基于此研究结果,可进一步明确激光钎焊是替代镍/铜箔片回流焊连接的可行性技术.Under the background of replacing aluminum copper direct welding with nickel foil"bridge",heterogeneous connection of nickel copper foil is carried out using reflow soldering and semiconductor laser soldering.A comparative analysis was conducted on the formation mechanism of joint morphology,weld seam and interface microstructure,and their mechanical properties were evaluated.The research results showed that the weld defects were not detected for two welded joints.The microstructure of laser soldering welds was composed of Sn solid solution and Cu-Sn intermetallic compounds(IMCs)with equiaxed crystal morphology,while microstructure of reflow soldering welds was composed of Sn solid solution.The Cu-Sn and Ni-Sn interfaces of the two joints showed different morphologies,and the thickness of the Cu-Sn interface layer was greater than that of Ni-Sn interface.The microstructure at the Cu-Sn interface during reflow soldering was scallop-shaped,consisting of Cu solid solution→Cu_(3)Sn IMCs→Cu_(6)Sn_(5)IMCs.For laser soldering joints,the Cu-Sn interface consisted of various Cu-Sn IMCs.At the Ni-Sn interface,a continuous distribution of(Cu,Ni)_(6)Sn_(5)IMCs was presented in the reflow soldering welds,while the short rodshaped(Cu,Ni)_(3)Sn_(4)and strip shaped(Cu,Ni)_(6)Sn_(5)was showed in the laser soldering welds.The maximum shear force values of the two joints can reach over_(3)20 N,far higher than actual production requirements.Based on this research results,it further demonstrated that laser soldering is a feasible technology to replace reflow soldering for the nickel/copper foil connection.

关 键 词：回流焊 激光钎焊 锡钎料 金属间化合物 

分 类 号：TG454[金属学及工艺—焊接]