真空封裝電容感應式微型圓環陀螺儀之研製

Abstract

本文以微機電製程在(111)單晶矽晶圓上製作具有柵狀質量塊之環式振動陀螺儀，並以7740玻璃晶圓製作陀螺儀之基座與感應電極層。利用柵狀質量塊與感應電極層的差動運動，進行待測物體之轉動物理量量測。 由於(111)單晶矽晶圓為等向性材料，因此沒有頻率偏移問題；但其原子排列密度高，所以使用電感耦合電漿蝕刻機進行製程。其中，使用陽極接合法進行矽材與玻璃的接合，而陀螺儀的封裝係以覆單晶矽玻璃方式，並於真空環境中進行封裝。如此可確保陀螺儀內部為真空空間，使得環形振子的運動不受空氣阻力影響，增加陀螺儀的靈敏度。

In this research, a micro-ring vibratory gyroscope with grid-like masses was fabricated on a (111) single-crystal silicon wafer by MEMS technology. The base and the electrode sensing layer of the gyroscope were fabricated with Corning Pyrex #7740 glasses. The gyroscope can be used to measure any object’s rotational information through differential motions between grid-like masses and the electrode sensing layer. The frequency-offset problem was solved by using (111) silicon to fabricate the gyroscope. However, due to the high density of atomic arrangement in (111) silicon, fabricating processes were difficult. The ICP was used to fabricate the main part of the gyroscope and ring oscillator. The anodic bonging process was used to bond (111) silicon and glasses. The SiOG process was used for the gyroscope packaging process. To ensure the internal part of gyroscope was in vacuum, the SiOG process must be done under vacuum environment. With such procedure, interferences between air resistances and ring oscillator’s motions can be avoided, and the sensitivity of the gyroscope can be enhanced.