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 ...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 μm,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 μs 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.展开更多
At present, high internal stress in SU-8 photoresist layer has become one of the most primary problems and restricted structure stability and higher aspect ratio of SU-8 photoresist. However, the existing studies all ...At present, high internal stress in SU-8 photoresist layer has become one of the most primary problems and restricted structure stability and higher aspect ratio of SU-8 photoresist. However, the existing studies all focused on optimizing the process pa-rameters or mask design, and could not be popularized. The purpose of this paper is to reduce the internal stress in cured SU-8 photoresist layer by ultrasonic stress relief technology. The ultrasonic stress relief mechanism in SU-8 photoresist layer was presented. Based on improved Stoney’s formula, the profile mothod calculation model for SU-8 internal stress was proposed. The effect of ultrasonic stress relief on SU-8 layers was studied by experiments. Some important factors, such as amplitude of vibration, power input and relief time, were discussed. The values of internal stress before and after the ultrasonic stress relief process were compared. The research results show that the internal stress in cured SU-8 layer can be reduced effectively if the proper experimental parameters are chosen, and ultrasonic stress relief technology in nonmetal field has some practical value.展开更多
基金supported by National Basic Research Program of China(973 Program,Grant No. 2007CB714502)National Natural Science Foundation of China (Grant No. 50675025)
文摘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 μm,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 μs 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.
基金supported by the National Natural Science Foundation of China (Grant No50675025)
文摘At present, high internal stress in SU-8 photoresist layer has become one of the most primary problems and restricted structure stability and higher aspect ratio of SU-8 photoresist. However, the existing studies all focused on optimizing the process pa-rameters or mask design, and could not be popularized. The purpose of this paper is to reduce the internal stress in cured SU-8 photoresist layer by ultrasonic stress relief technology. The ultrasonic stress relief mechanism in SU-8 photoresist layer was presented. Based on improved Stoney’s formula, the profile mothod calculation model for SU-8 internal stress was proposed. The effect of ultrasonic stress relief on SU-8 layers was studied by experiments. Some important factors, such as amplitude of vibration, power input and relief time, were discussed. The values of internal stress before and after the ultrasonic stress relief process were compared. The research results show that the internal stress in cured SU-8 layer can be reduced effectively if the proper experimental parameters are chosen, and ultrasonic stress relief technology in nonmetal field has some practical value.
