焊锡接头冷热循环组织性能演化及失效机理  

Microstructure and properties evolution and failure mechanism of solder joints after thermal cycling

作　　者：王冬梅[1] 刘广通[1] 有移亮[2] 张诚[1] 张伟[1] WANG Dong-mei;LIU Guang-tong;YOU Yi-liang;ZHANG Cheng;ZHANG Wei(Beijing Institute of Spacecraft Enviroment Engineering,Beijing 100094,China;School of Materials Science and Engineering,Beihang University,Beijing 100191,China)

机构地区：[1]北京卫星环境工程研究所,北京100094 [2]北京航空航天大学材料科学与工程学院,北京100191

出　　处：《材料热处理学报》2023年第1期164-171,共8页Transactions of Materials and Heat Treatment

基　　金：国家重点研发计划(2017YFC0805701);中国航天科技集团有限公司工艺专项GYGY2017-08《卫星舱外线缆装配及连接工艺技术研究》;教育部产学合作协同育人项目(201902206001)。

摘　　要：焊锡接头是卫星舱外线缆与器件引脚的常见连接方式,卫星在服役过程中舱外温度存在较大的波动,焊锡接头是易发生失效的部位之一。为研究焊锡接头的组织性能演化规律和失效机理,对其开展了-160~160℃范围内的冷热循环试验,并利用光学显微镜、显微硬度计、扫描电镜和有限元分析等对样品进行了分析。结果表明:冷热循环过程中焊料组织发生了粗化,Pb元素从富Sn相中析出并在富Pb相中发生团聚,晶界和相界发生弱化。由于引脚与焊料之间的热膨胀系数相差较大,使得冷热循环过程中靠近引脚表面的焊料存在较大的热应力,从而促进了该位置处Pb的析出和焊料组织粗化,造成富Pb相与基体相脱离并形成微裂纹。微裂纹在热应力的作用下发生扩展并相互连接,最终引发焊锡接头的整体开裂。Solder joint is a common connection mode of satellite extravehicular cables and device pins.The temperature outside the satellite cabin fluctuates greatly during the service of the satellite,and the solder joint is one of the parts prone to failure.In order to study the microstructure and property evolution and failure mechanism of the solder joint,the thermal cycling tests were carried out in the temperature range of -160-160℃,and the samples were analyzed by means of optical microscope,microhardness tester,scanning electron microscopy and finite element analysis.The results show that during the thermal cycling,the microstructure of the solder joint is coarsened,Pb elements precipitate from the Sn-riched phase and agglomerate in the Pb-riched phase,and the grain boundary and phase boundary are weakened.Due to the large difference in the thermal expansion coefficient between the pin and the solder,the solder near the pin surface has a large thermal stress during the thermal cycling,which promotes the precipitation of Pb and the coarsening of solder structure at this location,resulting in the separation of Pb-riched phase from the matrix phase and the formation of microcracks.Under the affect of thermal stress,microcracks propagate and connect with each other,eventually leading to the overall cracking of the solder joint.

关 键 词：焊锡 冷热循环 膨胀系数 组织偏聚 

分 类 号：TG146.4[一般工业技术—材料科学与工程] TG407[金属学及工艺—金属材料]