CNTs增强Sn-Bi基复合钎料回流焊焊点显微组织及力学性能  

Microstructure and Mechanical Properties of Reflow Solder Joints Prepared by CNTs Reinforced Sn-Bi Composite Solder

作　　者：黄清 彭倩群 张文妍 毛育青 HUANG Qing;PENG Qianqun;ZHANG Wenyan;MAO Yuqing(Engineering Training Center,,Nanchang Hangkong University,Nanchang 330063,China;National Defence Key Discipline Laboratory of Light Alloy Processing Science and Technology,Nanchang Hangkong University,Nanchang 330063,China;Hangzhi Intelligent Equipment(Taizhou)Co.,Ltd.,Jiangsu Taizhou 225500,China)

机构地区：[1]南昌航空大学工程训练中心,南昌330063 [2]南昌航空大学轻合金加工科学与技术国防重点学科实验室,南昌330063 [3]航知智能装备(泰州)有限公司,江苏泰州225500

出　　处：《精密成形工程》2024年第11期160-167,共8页Journal of Netshape Forming Engineering

基　　金：国家自然科学基金(52164045,52465044,52005240);江西省主要学科学术和技术带头人项目(20212BCJ23028);江西省杰出青年基金(20224ACB214012)。

摘　　要：目的为了解决Sn-Bi焊点难以满足高密度封装结构长期服役可靠性要求的难题,研制了CNTs增强Sn-Bi基复合钎料,并分析了复合钎料对焊点组织与力学性能的影响。方法采用机械混合方式制备了不同碳纳米管(CNTs)含量(0%、0.01%、0.025%、0.1%、0.25%,质量分数)的Sn-58Bi基复合钎料,随后采用回流焊方法对Cu薄板进行搭接焊。通过SEM、EDS等技术分析了焊点内的显微组织及界面金属间化合物(Inermetallic Compound,IMC)变化,并使用拉力测试仪研究了焊点剪切强度的变化规律。结果Cu/Sn-58Bi/Cu焊点的显微组织主要为黑色树枝状富Sn相和灰白色层片状富Bi的共晶组织,界面处IMC成分为扇贝状的Cu_(6)Sn_(5)相。添加CNTs可以明显细化组织晶粒,当CNTs质量分数为0.025%时,组织细化最明显。在Sn-58Bi钎料中添加一定量的CNTs可以明显提高焊点的剪切性能,当CNTs质量分数为0.025%时,焊点剪切性能最优,其剪切强度为27.5MPa,相较于Sn-58Bi/Cu焊点,提高了43.37%。结论在一定范围内,随着CNTs含量的增加,Sn-Bi-CNTs复合钎料焊点的显微组织得到明显细化,焊点拉剪性能显著提高。The work aims to prepare carbon nanotubes(CNTs)reinforced Sn-Bi composite solder and study its effect on microstructure and mechanical properties of solder joints to solve the problem that Sn-Bi solder joints are difficult to meet the long-term reliability requirements of high-density packaging structures.CNTs reinforced Sn-58Bi composite solder with differ-ent contents(0,0.01,0.025,0.1,0.25%wt.)were prepared by using the mechanical mixing method.Subsequently,Cu sheets were lap welded using composite solder by reflow soldering.The microstructure and interfacial intermetallic compound(IMC)of the solder joints were analyzed by SEM and EDS techniques.The tensile shear strength of the solder joints was tested with a tensile tester.The results showed that,the microstructure of Cu/Sn-58Bi/Cu solder joints was mainly composed of black den-dritic Sn-rich phase and gray white layered Bi-rich eutectic structure.The IMC composition at the interface was scallop-like Cu_(6)Sn_(5) phase.The addition of CNTs could significantly refine the grain size.When the mass fraction of CNTs was 0.025%,the microstructure was the finest.Adding a certain amount of CNTs into Sn-58Bi solder could significantly improve the tensile shear properties of the solder joints.Adding the content of the CNTs to 0.025 wt.%achieved the highest tensile shear properties with a maximum tensile shear strength of 27.5 MPa,and which was increased by 43.37%.Within a certain range,with the in-crease of CNTs content,the microstructure of Sn-Bi-CNTs composite solder joints is obviously refined,and the tensile shear properties of the solder joints are significantly improved.

关 键 词：碳纳米管 Sn-Bi钎料 回流焊焊点 微观组织 拉剪性能 

分 类 号：TG146[一般工业技术—材料科学与工程]