Design, fabrication, and vacuum package process for high performance of 2D scanning MEMS micromirror

We describe the design, fabrication, and high vacuum packaging process of 2D scanner. The resonant frequencies of 2D scanner after packaged in vacuum are 30 kHz and 290 Hz for the inner mirror and the gimbal frame, respectively. The rotation angles of packaged 2D scanner are 25° and 16° at driving voltages of 20 V and 12 V for the inner mirror and the gimbal frame, respectively. To compromise the requirement of hermetical seal and evacuation, a high-effective vacuum package method is introduced. The pressure in the package is estimated on the basis of measuring the quality factor of packaged 2D scanner. The obtained pressure in the package is lower than 5 Pa. The effect of package affecting to the performance of 2D scanner such the squeeze air film damping causing by pyrex window and substrate is also investigated in this paper.