Zhang Wenwu, Cao Yichen, Huang Jiayi, Zhao Weiwei, Liu Xiangli, Li Mingyu, Ji Hongjun
State Key Laboratory of Advanced Welding and Joining, Harbin Institute of Technology at Shenzhen, Shenzhen 518055, Guangdong, China; Flexible Printing Electronic Technology Center, Harbin Institute of Technology at Shenzhen, Shenzhen 518055, China.
Shenzhen Engineering Laboratory of Aerospace Detection and Imaging, Department of Materials Science and Engineering, Harbin Institute of Technology at Shenzhen, Shenzhen 518055, China.
Ultrason Sonochem. 2020 Sep;66:105090. doi: 10.1016/j.ultsonch.2020.105090. Epub 2020 Mar 25.
The high-melting-point joints by transient-liquid-phase are increasingly playing a crucial role in the die bonding for the high temperature electronic components. In this study, three kinds of Sn/Ni composite solder pastes composed of different sizes of Ni particles were synthesized to accelerate metallurgical reaction among Sn/Ni interfaces under the ultrasonic-assisted transient liquid phase (U-TLP) soldering. The temperature evolution, microstructure and mechanical property in joints composed by these composite solder pastes with or without ultrasonic energy were systemically investigated. The intermetallic joint consisted of high-melting-point sole NiSn intermetallic compound with a little residual Ni was obtained under the conditions of no pressure and lower power (200 W) in a high-temperature duration of only 10 s, its shear strength was up to 45.3 MPa. Ultrasonic effects significantly accelerated the reaction among the interfaces of liquid Sn and solid Ni, which attributed to the temperature rise caused by acoustic cavitation because of large number of liquid/solid interfaces during U-TLP, resulting in accelerated solid/liquid interfacial diffusion and growth of intermetallic compounds. This intermetallic joint formed by U-TLP soldering has a promising potential for applications in high-power device packaging.
通过瞬态液相形成的高熔点接头在高温电子元件的芯片键合中越来越发挥着关键作用。在本研究中，合成了三种由不同尺寸镍颗粒组成的锡/镍复合焊膏，以在超声辅助瞬态液相（U-TLP）焊接过程中加速锡/镍界面间的冶金反应。系统研究了有无超声能量作用下，由这些复合焊膏形成的接头的温度演变、微观结构和力学性能。在无压力和较低功率（200W）且高温持续仅10s的条件下，获得了由高熔点单一镍锡金属间化合物和少量残余镍组成的金属间接头，其剪切强度高达45.3MPa。超声效应显著加速了液态锡与固态镍界面间的反应，这归因于U-TLP过程中大量液/固界面因声空化导致的温度升高，从而加速了金属间化合物的固/液界面扩散和生长。通过U-TLP焊接形成的这种金属间接头在高功率器件封装中具有广阔的应用前景。
