热时效对铜核SAC305微焊点组织及性能的影响

热时效对铜核SAC305微焊点组织及性能的影响 Effect of thermal aging on microstructure and properties of Cu-cored SAC305 micro-solder joints 张焱 ZHANG Yan 1 first-author 零的应 LING Diying 1 姚宗湘 YAO Zongxiang 1 corresp yaozongx@163.com 刘义凯 LIU Yikai 1 田佳俊 Tian Jiajun 1 尹立孟 YIN Limeng 1 陈玉华 CHEN Yuhua 2 重庆科技学院 重庆科技学院 Chongqing University of Science and Technology Chongqing University of Science and Technology 南昌航空大学 南昌航空大学 Nanchang Hangkong University Nanchang Hangkong University 对Cu/Cu-cored+SAC305/Cu微焊点及Cu/SAC305/Cu微焊点进行不同时长的热时效试验。借助扫描电镜(SEM)、动态力学分析仪(DMA)等手段,分析热时效时间对两种结构钎料焊点界面显微组织及拉伸性能的影响。结果表明:随着热时效时间的增加,焊点界面组织晶粒逐渐粗化,IMC层逐渐增厚,焊点的抗拉强度不断降低。与Cu/SAC305/Cu焊点相比,在热时效时间相同的情况下,添加Cu核可以减缓焊点界面IMC的生长速率,提高焊点的抗拉强度,而对焊点微观结构形貌的影响不显著。经断口分析发现,两种焊点断口均表现为脆性断裂特征;但Cu/Cu-cored+SAC305/Cu焊点断口表面有少量韧窝,表现出一定的韧性。 The Cu/Cu-cored+SAC305/Cu and Cu/SAC305/Cu micro-solder joints were subjected to thermal aging tests with different length. The effects of thermal aging time on the interfacial microstructure and tensile properties of these two solder joints were analyzed by scanning electron microscope（SEM） and dynamic mechanical analyzer（DMA）. The results show that the grains in interfacial microstructures of solder joints gradually coarsen,the IMC layers become thicker and the tensile strength of solder joints reduce with increasing aging time. Compared with Cu/SAC305/Cu solder joints,under the same thermal aging time,adding Cu-cored can slow down the growth rate of IMC at solder joint interface and improve the tensile strength of solder joint,but has no significant effect on the microstructure morphologies of solder joints. Fracture analysis shows that the two kinds of solder joints are brittle fracture. However,there are a small number of dimples on the fracture surface of Cu/Cu-cored +SAC305/Cu solder joints,showing certain toughness. 铜核焊点 热时效 界面化合物 抗拉强度 Cu-cored solder joint thermal aging intermetallic compound（IMC） tensile strength TG407;TG156.92 重庆市自然科学基金（cstc2019jcyj-msxmX0175,cstc2020jcyj-msxmX0552）;国家级大学生创新训练计划项目（201911551005） 2022-03-08 7 51