摘要
研究了焊点高度为10μm的Cu/Sn/Cu微焊点接头在110℃下分别进行200、400、600、800h等温时效后界面CuSn金属间化合物的显微组织及剪切强度的演变。结果表明,随着时效时间延长,界面的金属间化合物由初始的扇贝状Cu-_6Sn_5组织逐渐演变为层状的Cu_3Sn和Cu_6Sn_5组织,并且界面金属间化合物在时效作用下不断消耗钎缝中的β-Sn向焊点中部生长,800h时效后焊点组织完全被Cu_3Sn和Cu_6Sn_5金属间化合物所取代;另外,随着时效时间的延长及界面金属间化合物的演变,焊点的剪切强度不断提高,其中当时效时间达到400h时,两端界面金属间化合物发生部分接合,剪切强度增幅较大;800h时效后试样的剪切强度为最大值。断口形貌分析表明,随着时效时间延长,焊点的断裂机制由韧性剪切断裂演变为脆性剪切断裂。
A series of sandwich structure of Cu/Sn/Cu solder joints with the bump height of 10μm were prepared to understand the effects of the isothermal aging on the microstructure and shearing strength of the joints aged at 110 ℃ for 200,400,600,800 h,respectively,and microstructure evolution of the joints was characterized by SEM equipped with EDS.The results reveal that the scalloped-like Cu6Sn5 intermetallic compound（IMC）at soldering changed gradually into the combination layers of Cu3 Sn and Cu6Sn5 IMC with aging time increase,and the two layers of IMC grown thicker as a result of consumingβ-Sn in the soldering during aging process.In addition,with increasing in aging time and IMC evolution,shearing strength of the joint is increased gradually,and a part of the IMC from both sides is contacted with each other at the middle of the joints after aging for 400 h,and the shear strength came to maximum after aging for 800 h.The fracture mechanism is changed from ductile fracture to brittle fracture gradually.
作者
刘恒林
卫国强
李达磊
Liu Henglin Wei Guoqiang Li Dalei(School of Mechanical and Automotive Engineering, South China University of Technolog)
出处
《特种铸造及有色合金》
CAS
CSCD
北大核心
2017年第3期302-305,共4页
Special Casting & Nonferrous Alloys
基金
国家自然科学基金资助项目(51371083)
