摘要
利用激光喷射锡球键合(LJSBB)技术,通过设置不同的激光能量和回流次数,并采用微焊点横截面试样和SEM/EDX以及热冲击测试等方法,对比研究了激光能量和回流次数对直角型Au/Sn-3.0Ag-0.5Cu/Au微焊点初始界面微观组织和热冲击性能的影响.结果表明:激光能量和回流可以显著影响界面金属间化合物(IMC)的形态和分布,随着能量增加,远离Au层弥散分布的细小近棒状AuSn4转变为粗大的针状或层状组织;再次回流后,在微焊点温度梯度较大的尖角处容易形成层状AuSn4相,而在焊点基体内部的界面附近形成粗大的针状AuSn4相;较低能量条件下键合后的微焊点焊盘上残留的Au层为热循环过程中IMC相的生成提供了充足的Au原子,导致界面组织粗大并出现微裂纹,进而削弱抗热冲击性能.
The influence of laser energy and times of backflow on initial interfacial microstructure and thermal shock performance of right-angle-type Au/Sn-3.0Ag-0.5Cu/Au micro-solder joints was comparatively studied by employing the technique of laser jet solder ball bonding（LJSBB）,setting different laser energy and reflow times,and using the characterization means and method such as sample of micro-solder joints,SEM/EDX,and thermal shock test.The result showed that the laser energy and reflow will have significant influence on the morphology and distribution of the interfacial intermetallic compound（IMC）.With increasing laser energy,the dispersed and fine rod-like AuSn4 far from Au layer would convert into coarse needle-like or layerlike structure.After multiple reflowing,the layerlike AuSn4 phase would easily be formed at the sharp corner of the right-angle solder joint with higher temperature gradient,while the needle-like AuSn4 phase would occur at the adjacencies of the interface in the matrix of the solder joint.The residual Au layer on micro-soldering pad after joint bonding under condition of lower laser energy would be able to provide enough Au atoms for IMC phase forming during thermal cycling,resulting in coarse interfacial structure and micro-cracks,so that the anti-thermal shock performance of the joint would be weakened.
出处
《兰州理工大学学报》
CAS
北大核心
2016年第3期26-30,共5页
Journal of Lanzhou University of Technology
基金
国家自然科学基金(51565024)
甘肃省高等学校科研基金(2015A-160)
关键词
激光喷射锡球键合
激光特性
直角型微焊点
界面微观组织
可靠性
laser jet solder ball bonding（LJSBB）
laser characteristics
right-angle micro-solder joint
in terfacial microstructure
reliability
