Study on nano-scale roundness measurement method of MEMS components

Using atom force tip of scanning probe microscope (SPM) as a sensor, and precision air-bearing to rotate the sample, a measurement apparatus was developed to measure the roundness of MEMS micro-components in sub-millimeter scale. The measuring principle and some design problems of key techniques, including precision air-bearing, driven motor, fixture and aligning devices were discussed. By this system the outer surface of a micro electrode about 0.2 mm in diameter was measured. Filtered the measurement data, the roundness error was calculated according to the least square circle criterion and the result is 3.2102 μm. This work provides a feasible measurement method and instrument for the manufacturing technique of MEMS components.