Tham khảo tài liệu 'the mems handbook introduction & fundamentals (2nd ed) - m. gad el hak part 2', kỹ thuật - công nghệ, cơ khí - chế tạo máy phục vụ nhu cầu học tập, nghiên cứu và làm việc hiệu quả | Mechanical Properties ofMEMS Materials 3-7 could be rotated about an axis perpendicular to the grid. This caused all of the specimens to buckle each a different amount than its neighbor. When the grip moved each specimen in turn was straightened and pulled. The recorded force-displacement record enabled measurement of modulus and strength. Specimen in Frame Read and Dally 1992 introduced a very effective way of handling thin-film specimens in 1992. The tensile specimen is patterned onto the surface of a wafer and then a window is etched in the back of the wafer to expose the gauge section. The result is a specimen suspended across a rectangular frame which can be handled easily and placed into a test machine. The two larger ends of the frame are fastened to grips and the two narrower sides are cut to completely free the specimen. This is an extension of the much earlier approach by Neugebauer 1960 and has been adopted by others Cunningham et al. 1995 Emery et al. 1997 Ogawa et al. 1997 Sharpe et al. 1997c Cornella et al. 1998 Yi and Kim 1999b . A SEM photograph of such a specimen while still in the frame is shown in Figure . Specimen Fixed at One End Tsuchiya introduced the concept of a tensile specimen fixed to the die at one end and gripped with an electrostatic probe at the other end Tsuchiya et al. 1998 . This approach has been adopted by this author and his students Sharpe et al. 1998a Figure is a photograph of this type of specimen. The gauge section is pm thick 50 pm wide and 2 mm long. The fixed end is topped with a gold layer for electrical contact. The grip end is filled with etch holes as are the two curved transition regions from the grips FIGURE Scanning electron micrograph of a polysilicon tensile specimen in a supporting single-crystal silicon frame. Reprinted with permission from Sharpe . Jr. Yuan B. Vaidyanathan R. and Edwards . 1996 Proc. SPIE 2880 pp. 78-91. FIGURE A tensile specimen fixed at the left end
