银微纳颗粒复合薄膜连接接头高保温组织性能演变  

Microstructureand Property Evolutions of Joints Sintered by Silver Micro-and Nano-particles Composite Film

作　　者：王文淦 贾强[1] 阿占文 冯斌 赵文正[1] 白海林[1] 邹贵生[1] Wang Wengan;Jia Qiang;A Zhanwen;Feng Bin;Zhao Wenzheng;Bai Hailin;Zou Guisheng(State Key Laboratory of Tribology,Department of Mechanical Engineering,Tsinghua University,Beijing 100084,China)

机构地区：[1]清华大学机械工程系摩擦学国家重点实验室,北京100084

出　　处：《中国激光》2021年第8期169-178,共10页Chinese Journal of Lasers

基　　金：国家重点研发计划(2017YFB1104900);国家自然科学基金(51775299,52075287,51520105007)。

摘　　要：采用脉冲激光沉积方法在待连接母材表面沉积制备无有机物的银微纳颗粒复合薄膜,用该薄膜作为中间层低温烧结连接SiC芯片与金属化陶瓷基板。将连接接头置于大气、真空及氧气含量可控环境进行300℃高温存储实验,系统研究了保温环境对接头多孔连接层的组织演变和性能影响规律。结果表明:保温2000 h以内,接头在室温下的剪切强度均高于20 MPa且明显高于美国军标。大气环境保温0~400 h期间,连接层内部孔隙逐渐聚集并导致组织致密化,接头强度提升;保温400~2000 h期间的孔隙聚集与扩大导致孔隙率明显增加,强度逐渐下降。真空环境对连接层内孔隙演变存在阻碍作用。保温环境的氧浓度提升可加速烧结连接层组织在高温存储过程中的演变进程。Objective With the application of new generation power electronic devices,their advantages in severe working conditions are gradually emerging.For instance,SiC power devices can serve in high-temperature conditions over 300℃,and their packaging materials should be bonded at low temperature(≤250℃)and work reliably in high-temperature conditions.Sintering silver nanoparticles(NPs)technology is an effective method that can form joints with excellent electrical and thermal properties between SiC chips and metallized substrates.The traditional silver NP-sintering technology is synthesizing NPs by a chemical method and mixing them with organic components to prepare pastes.However,the adverse effects of organic components in the pastes can reduce the performance of sintered joints;thus,organic-free solutions have emerged recently.Pulsed laser deposition(PLD)with ultrafast laser as the light source is an efficient method to prepare organic-free silver-nanostructured films with large areas.Ultrafast laser with a very high peak power can ablate a target and produce ions with high kinetic energy,which can be controlled by the atmosphere to form films with unique nanostructures.In this study,organic-free silver micro-particle and NP composite film(SMNCF)was prepared by a PLD method on SiC chips.The films were used as intermediate layers for the low-temperature sintering process to bond SiC chips and metallized ceramic substrates.The size distribution of the as-prepared nanosilver films is diverse and controllable,and the sintering temperature can be as low as 180℃,which meets the shear strength requirements of SiC power devices.Methods In this study,SiC chips with deposited SMNCF were mounted on silver metallized substrates to form modules.These modules were sintered at 250℃with 10 MPa applied pressure for 30 min.In addition,samples in control groups were prepared with hybrid silver NP pastes.The modules were dried at 150℃for 5 min and then maintained at 250℃for 30 min under 10 MPa applied pressure to complete

关 键 词：激光技术 材料 银微纳颗粒复合薄膜 脉冲激光沉积 低温烧结连接 高温可靠性 

分 类 号：O436[机械工程—光学工程]