Quality factor measurement of micro gyroscope structure according to vacuum level and desired Q-factor range package method

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• 作者：Jong-Seok Kim ; Sang-Woo Lee ; Kyu-Dong Jung ; Woon-Bae Kim ; Sung-Hoon Choa ; Byeong-Kwon Ju
• 关键词：Asteroids ; Collisional physics ; Impact processes
• 刊名：Microelectronics Reliability
• 出版年：2008
• 出版时间：June 2008
• 年：2008
• 卷：48
• 期：6
• 页码：948-952
• 全文大小：1213 K

文摘

A micro-machined gyro chip of gyroscope is normally packaged in specific vacuum level to get the specific quality factor(Q-factor). If the Q-factor is too high, frequency tuning and the approximate matching between driving and sensing comb structure become difficult, and if the Q-factor is too low, its sensitivity decreases. The optimum Q-factor of our gyro chip design is 4000 range. To get this range, we measured the drive mode Q-factor as vacuum level of our gyro chip and we found that the vacuum level of the desired Q-factor 4000 is in the range of 740 mTorr. Based on this data, we fabricate the wafer level package gyro chip of the desired Q-factor by controlled the basic pressure of package bonding chamber just prior to the bonding process. After wafer level package process, we measured Q-factor of whole samples. Among 804 samples, 502 packaged gyro chips are worked and the Q-factor of 67 % samples is between 3500 and 4500 range.