Hu Tengjiang, Fang Kuang, Zhang Zhiming, Jiang Xiaohua, Zhao Yulong
State Key Laboratory for Manufacturing System Engineering, Xi'an Jiaotong University, Xi'an 710049, China.
Institute of Chemical Materials, China Academy of Engineering Physics, Mianyang 621900, China.
Micromachines (Basel). 2019 Jul 13;10(7):469. doi: 10.3390/mi10070469.
The micro-electromechanical system (MEMS) safety-and-arming (S&A) device has the features of integration and miniaturization, which is one of the important directions of weapon development. Confined by the fabrication process, the silicon-based devices are too fragile, and the metal-based devices are low precision. In order to solve the contradiction between high precision and high structure strength, a metal/silicon composite structure is proposed in this paper, and a hybrid fabrication process is introduced. This new method mainly consists of metal sputtering, electroplating, and (inductively-coupled-plasma) ICP etching. As the resolution of the thick dry film is limited, the process of a femtosecond laser is applied to refine the structure, and the Ni plate (a block of 1 mm × 3 mm × 0.3 mm with a cavity of ϕ 0.85 mm × 0.3 mm in the center) is fabricated on the silicon-on-insulator (SOI) wafer successfully. After the double sides are etched by ICP, the SOI wafer is immersed in a buffered-oxide-etch (BOE) etchant to remove the buried layer. The cover plate acts as the encapsulation and is bonded with the SOI wafer by the epoxy glue. Then, the temporary support beam of the device is broken by the probe, and the suspended composite structure can be fully released. The hybrid process is the integration of the silicon-based process and the metal-based process, which can combine the advantages of both high precision and a high structure strength. The process proposed here is suitable for the application of weapon miniaturization.
微机电系统（MEMS）安全与解除保险（S&A）装置具有集成化和小型化的特点，是武器发展的重要方向之一。受制造工艺限制，硅基器件过于脆弱，而金属基器件精度较低。为了解决高精度与高结构强度之间的矛盾，本文提出了一种金属/硅复合结构，并引入了一种混合制造工艺。这种新方法主要包括金属溅射、电镀和电感耦合等离子体（ICP）蚀刻。由于厚干膜的分辨率有限，应用飞秒激光工艺对结构进行细化，并成功地在绝缘体上硅（SOI）晶圆上制造出镍板（一块1mm×3mm×0.3mm的方块，中心有一个直径为0.85mm×0.3mm的腔）。通过ICP对双面进行蚀刻后，将SOI晶圆浸入缓冲氧化物蚀刻（BOE）蚀刻剂中以去除掩埋层。盖板用作封装，并通过环氧树脂与SOI晶圆键合。然后，用探针折断器件的临时支撑梁，即可完全释放悬空的复合结构。混合工艺是硅基工艺和金属基工艺的集成，它可以结合高精度和高结构强度这两个优点。这里提出的工艺适用于武器小型化应用。
