Fabrication of Fuze Micro-electro-mechanical System Safety Device

Fuze micro-electro-mechanical system(MEMS) has become a popular subject in recent years. Studies have been done for the application of MEMS-based fuze safety and arm devices. The existing researches mainly focused on reducing the cost and volume of the fuze safety device. The reduction in volume allows more payload and, thus, makes small-caliber rounds more effective and the weapon system more affordable. At present, MEMS-based fuze safety devices are fabricated mainly by using deep reactive ion ething or LIGA technology, and the fabrication process research on the fuze MEMS safety device is in the exploring stage. In this paper, a new micro fabrication method of metal-based fuze MEMS safety device is presented based on ultra violet(UV)-LIGA technology. The method consists of SU-8 thick photoresist lithography process, micro electroforming process, no back plate growing process, and SU-8 photoresist sacrificial layer process. Three kinds of double-layer moveable metal devices have been fabricated on metal substrates directly with the method. Because UV-LIGA technology and no back plate growing technology are introduced, the production cycle is shortened and the cost is reduced. The smallest dimension of the devices is 40 mu m, which meets the requirement of size. To evaluate the adhesion property between electroforming deposit layer and substrate qualitatively, the impact experiments have been done on the device samples. The experimental result shows that the samples are still in good condition and workable after undergoing impact pulses with 20 kg peak and 150 mu s duration and completely met the requirement of strength. The presented fabrication method provides a new option for the development of MEMS fuze and is helpful for the fabrication of similar kinds of micro devices.