• CN:11-2187/TH
  • ISSN:0577-6686

机械工程学报 ›› 2022, Vol. 58 ›› Issue (2): 259-268.doi: 10.3901/JME.2022.02.259

• 微纳连接界面与可靠性 • 上一篇    下一篇

扫码分享

电子封装跨尺度凸点结构Sn3.0Ag0.5Cu/Cu微互连焊点界面IMC生长与演化及力学行为的尺寸效应

周敏波1,2, 赵星飞1,2, 陈明强1,2, 柯常波1,2, 张新平1,2   

  1. 1. 华南理工大学材料科学与工程学院 广州 510640;
    2. 华南理工大学广东省电子封装材料与可靠性工程技术研究中心 广州 510640
  • 收稿日期:2021-05-17 修回日期:2021-08-28 出版日期:2022-01-20 发布日期:2022-03-19
  • 通讯作者: 张新平(通信作者),男,1965年出生,博士,教授,博士研究生导师。主要研究方向为电子封装与可靠性、机敏材料、材料计算及材料加工模拟与仿真。E-mail:mexzhang@scut.edu.cn
  • 作者简介:周敏波,男,1981年出生,博士,讲师,硕士研究生导师。主要研究方向为先进电子封装材料与结构可靠性。E-mail:msmbzhou@scut.edu.cn
  • 基金资助:
    国家自然科学基金(51775195,51405162)、广东省科技计划公益研究与能力建设专项(2016A010103010)和中央高校基本科研业务费(SCUT-2017ZD038)资助项目。

Size Effects of Growth and Evolution of Interfacial Intermetallic Compound and the Mechanical Behavior of Bump Structure Sn3.0Ag0.5Cu/Cu Cross-scale Joints in Electronic Packages

ZHOU Minbo1,2, ZHAO Xingfei1,2, CHEN Mingqiang1,2, KE Changbo1,2, ZHANG Xinping1,2   

  1. 1. School of Materials Science and Engineering, South China University of Technology, Guangzhou 510640;
    2. Guangdong Provincial Engineering R&D Center of Electronic Packaging Materials and Reliability, South China University of Technology, Guangzhou 510640
  • Received:2021-05-17 Revised:2021-08-28 Online:2022-01-20 Published:2022-03-19

摘要: 针对目前无铅电子封装中主流应用的Sn3.0Ag0.5Cu钎料,研究了其直径为600~60 μm的焊球在开孔型Cu基底(焊盘)上260℃恒温回流不同时间(10~300 s)形成跨尺度凸点结构Sn3.0Ag0.5Cu/Cu微互连焊点时界面金属间化合物(IMC)的生长与演化行为,以及跨尺度微焊点的剪切性能与断裂行为。研究结果表明,焊球直径大于200 μm时焊点界面IMC生长速率随其尺寸减小而增大,而焊球直径小于200 μm时焊点界面IMC生长速率随焊球直径减小呈减小趋势。对微焊点界面显微组织演化的分析表明,界面IMC的粗化生长过程随回流时间延长依次经历了奥斯瓦尔德熟化生长及晶粒吸附与晶界迁移生长两个阶段,且其生长阶段的转变随焊点尺寸减小而更早发生。准静态剪切加载条件下的试验结果表明,微焊点强度随其尺寸减小而增加,而恒温回流时间增加时(10~300 s)同尺寸微焊点的剪切强度并未出现明显变化,但回流时间对大尺寸焊点剪切断裂位置有明显影响。

关键词: 微焊点, 金属间化合物, 晶粒生长, 剪切性能, 尺寸效应

Abstract: A mainstream lead-free Sn3.0Ag0.5Cu solder with cross-scale ball diameters in the range of 600 μm to 60 μm was used to attach on Cu pads to form micro-bump structure Sn3.0Ag0.5Cu/Cu(SAC305/Cu) joints by reflow at 260℃ for different dwelling times of 10 to 300 s. The microstructure evolution of interfacial intermetallic compound(IMC),shear strength and fracture behavior of SAC305/Cu cross-scale joints were investigated. Results show that for solder balls with diameter larger than 200 μm the growth rate of interfacial IMC layer of the joints increases with the decreasing solder joint size, while decreasing with the decrease of the solder joint size for solder balls with diameter less than 200 μm. Meanwhile, the coarsening growth of interfacial IMC grains exhibits two featured stages:Ostwald ripening growth and grain boundary absorption/migration growth, and the transition between two growth stages occurs earlier as the size of solder joints decreases. Under quasi-static shear loading, the shear strength of Sn3.0Ag0.5Cu/Cu joints increases with the decrease of the solder joint size. In the range of reflow time from 10 s to 300 s, the reflow time has little influence on shear strength of the joints, while showing an obvious effect on the fractural path of the joints.

Key words: microscale solder joint, intermetallic compound, grain growth, shear performance, size effect

中图分类号: