Wang Yanbin, Yu Mingzhi, Chen Yao, Ma Yintao, Han Xiangguang, Xia Yong, Guo Ju, Yang Ping, Lin Qijing, Ding Shujiang, Zhao Libo
State Key Laboratory for Manufacturing Systems Engineering, International Joint Laboratory for Micro/Nano Manufacturing and Measurement Technologies, State Industry-Education Integration Center for Medical Innovations at Xi'an Jiaotong University, Xi'an Jiaotong University (Yantai) Research Institute for Intelligent Sensing Technology and System, Xi'an Jiaotong University, Xi'an, 710049, China.
School of Mechanical Engineering, Xi'an Jiaotong University, 710049, Xi'an, China.
Microsyst Nanoeng. 2025 Aug 14;11(1):153. doi: 10.1038/s41378-025-00976-6.
The development of micro-electro-mechanical system (MEMS) alkali metal vapor cells offers the potential for the batch fabrication of micro-quantum sensors for atomic clocks, atomic magnetometers and atomic gyroscopes. The sealing of MEMS vapor cells is traditionally achieved by anodic bonding. However, high-temperature and high direct-voltage conditions during anodic bonding adversely affect the performance of the vapor cell. In this study, a fabrication method based on ultrafast laser welding integrated with a microfabrication process was developed for MEMS alkali metal vapor cells, and the energy-coupling mechanism of welding was analyzed. This method confined high temperatures to a localized area during laser welding. The cross-sections of the welding samples were analyzed, the element distribution was characterized, and the results showed that this method achieved high-strength sealing. Additionally, a platform for alkali metal injection and buffer gas charging was developed to enable the fabrication of MEMS vapor cells with ultrafast laser welding. The MEMS vapor cells were tested using absorption spectra, and the leakage rate under high-temperature vacuum conditions proved that high hermeticity could be achieved by ultrafast laser welding. Finally, MEMS vapor cells were used to fabricate a single-beam magnetometer, and its measurement sensitivity was determined experimentally. This process provides a new method for the efficient fabrication of MEMS vapor cells.
微机电系统（MEMS）碱金属蒸汽池的发展为批量制造用于原子钟、原子磁力计和原子陀螺仪的微量子传感器提供了潜力。传统上，MEMS蒸汽池的密封是通过阳极键合实现的。然而，阳极键合过程中的高温和高直流电压条件会对蒸汽池的性能产生不利影响。在本研究中，开发了一种基于超快激光焊接并与微制造工艺相结合的制造方法用于MEMS碱金属蒸汽池，并分析了焊接的能量耦合机制。该方法在激光焊接过程中将高温限制在局部区域。对焊接样品的横截面进行了分析，对元素分布进行了表征，结果表明该方法实现了高强度密封。此外，还开发了一个碱金属注入和缓冲气体充注平台，以实现采用超快激光焊接制造MEMS蒸汽池。使用吸收光谱对MEMS蒸汽池进行了测试，高温真空条件下的泄漏率证明超快激光焊接可以实现高气密性。最后，使用MEMS蒸汽池制造了单光束磁力计，并通过实验确定了其测量灵敏度。该工艺为高效制造MEMS蒸汽池提供了一种新方法。
