Popis: |
A novel Micro Electro Mechanical System (MEMS) measurement device for straightness measurement with a three point method has been proposed. This device integrates three cantilever displacement sensors with a narrow pitch on a silicon chip. The authors determine appropriates shape, dimensions of the cantilever, and a fabrication process. According to simulation results, a triangular cantilever with altitude 12 mm long, base 4mm long, and 0.25 mm thickness was adopted to realize the target measuring range of 100 μm. Near the end of each cantilever, a square frustum probe 250 μm high which was fabricated by anisotropic wet etching was placed. Near the base of cantilevers, four piezo resistance gauges were formed; two are active gauges for measuring stress arise from a displacement at the probe and the others are dummy gauges for temperature compensation. Wiring and contact terminals were fabricated on the base substrate and the total size of the device is 20 mm × 32 mm. The fabrication process of this device was designed and result of a trial production was reported. |