摘要
为了解构件尺寸的微型化给材料的强度带来的影响 ,利用纳米硬度计通过微悬臂梁的弯曲试验法来测量多晶硅微构件弯曲强度 ,利用电磁驱动微拉伸装置测试了抗拉强度。试验研究表明 ,多晶硅微构件的弯曲强度和抗拉强度表现出随构件尺寸的减小而增加的尺寸效应。统计分析表明 ,多晶硅微构件的平均弯曲强度为 ( 2 .885± 0 .40 8)GPa ,其平均抗拉强度为 ( 1.36± 0 .14 )GPa。
Micro-electro-mechanical system (MEMS) is a newly rising interdisciplinary, technology. The mechanical design of MEMS is one of the frontiers of mechanical engineering. The increasing use of small micro-electro-mechanical system (MEMS) and advanced sensors has lead to concern about the failure modes and reliability of these structures. This depends on the solution of materials issues associated with the design and fabrication of complex MEMS devices. The reliable mechanical properties of these thin films are critical to the safety and functioning of these microdevices and should be accurately determined. This paper takes up the key point among the existing problems in the development of MEMS, the mechanical behavior of MEMS materials, for investigating experimentally in detail. To investigate the specimen size influence on fracture strength of microstructures, the validity of a novel, direct and convenient method for bending strength measurements by beam bending using a nanoindenter has been demonstrated. The tensile strength of polysilicon thin films was measured with a microtensile test device with a magnet solenoid actuator and a fibre optical displacement sensor. The bending strength of microfabricated polysilicon beams with dimensions of 16 [similar to] 34 μm long, 10 [similar to] 50 μm wide, and 2.4 μm thick was evaluated. The tensile mechanical properties of microfabricated polysilicon thin films with dimensions of 100 [similar to] 660 μm long, 20 [similar to] 200 μm wide, and 2.4 μm thick were also evaluated. The result shows that bending strength and tensile strength of polysilicon microstructures show size effect on the size of the specimens. Statistical analysis of bending strength and tensile strength for various specimen sizes shows that the average bending strength of polysilicon microcantilever beams is (2.885 ± 0.408) GPa, and the average tensile strength of polysilicon thin films is (1.36 ± 0.14) GPa. Statistical analysis of the specimen size effects on the tensile strength predicated the
出处
《机械强度》
EI
CAS
CSCD
北大核心
2001年第4期385-388,共4页
Journal of Mechanical Strength
基金
国家教委高校博士点基金 (2 0 0 0 0 0 0 338)
