Jin Xiao, Jia Luo, Qi-Xing Zhou, Hao Zhang, Liu Jun-Hui, Xi-Feng Huang
School of Intelligent Manufacturing and Materials Engineering, Gannan University of science and technology, No. 156, Kejia Rd., Zhanggong District, Ganzhou City, 341000, Jiangxi Province, People's Republic of China.
School of Advanced Manufacturing, Guangdong Songshan Polytechnic College, Shaoguan, 512100, People's Republic of China.
Sci Rep. 2025 May 22;15(1):17847. doi: 10.1038/s41598-025-02798-y.
The special shape of Cu/In layer and ultrasonic vibration are used to realize fast bonding at room temperature, thus solving the problems of high thermal stress and signal delay caused by high temperature in the traditional reflow soldering process. The indium film-modified copper crystal microlayer substrates are used as bonding couples, and ultrasonic vibration and pressure are applied to the bonding contact area to realize the rapid solid-phase bonding of two copper substrates. The microstructure, intermetallic compounds and average shear strength at the bonding interface are analyzed by scanning electron microscopy, transmission electron microscopy, X-ray diffraction (XRD) and bond strength tester. Under ultrasonic vibration and small pressure, the micro-cone structures of Cu/In layers are inserted into each other to form a stable physical barrier structure. The atoms of the thin indium layer at the bonding interface transform into the high-quality phase CuIn by rapid diffusion driven by ultrasonic energy. When the thickness of the indium layer at the bonding interface is 250 nm, the bonding pressure is 7 MPa, and the bonding time is 1 s, the relatively optimal bonding quality is obtained, and the holes at the bonding interface disappear. The results of heat treatment experiments show that this solid-phase bonding technique can obtain good bond strength without additional heat treatment. The special morphology of the Cu/In layer and ultrasonic vibration allow the bonding to be completed quickly at room temperature. The bonding quality is good and small bond sizes can be obtained.
利用Cu/In层的特殊形状和超声振动在室温下实现快速键合，从而解决了传统回流焊接工艺中高温导致的热应力高和信号延迟问题。采用铟膜改性铜晶体微层基板作为键合对，对键合接触区域施加超声振动和压力，实现两个铜基板的快速固相键合。通过扫描电子显微镜、透射电子显微镜、X射线衍射（XRD）和键合强度测试仪分析键合界面的微观结构、金属间化合物和平均剪切强度。在超声振动和小压力作用下，Cu/In层的微锥结构相互插入，形成稳定的物理阻挡结构。键合界面处薄铟层的原子在超声能量驱动下通过快速扩散转变为高质量相CuIn。当键合界面铟层厚度为250 nm、键合压力为7 MPa、键合时间为1 s时，可获得相对最优的键合质量，键合界面处的孔洞消失。热处理实验结果表明，这种固相键合技术无需额外热处理即可获得良好的键合强度。Cu/In层的特殊形貌和超声振动使得键合能够在室温下快速完成。键合质量良好，且可获得较小的键合尺寸。
