A packaged silicon MEMS vibratory gyroscope for microspacecraft

• Main Authors: Tang, T.K., Gutierrez, R.C., Stell, C.B., Vorperian, V., Arakaki, G.A., Rice, J.T., Li, W.J., Chakraborty, I., Shcheglov, K., Wilcox, J.Z., Kaiser, W.J.
• Format: Conference Proceeding
• Language: English
• Subjects: Amplifiers; Circuit testing; Electronic equipment testing; Electronics packaging; Fabrication; Gyroscopes; Hermetic seals; Microelectromechanical systems; Micromechanical devices; Silicon
• ISSN: 1084-6999
• DOI: 10.1109/MEMSYS.1997.581911

In this paper, we present recent work on the design, fabrication, and packaging of a silicon Micro-Electro-Mechanical System (MEMS) microgyroscope designed for space applications. A hermetically sealed package that houses the microgyroscope and most of its control electronics has been built and tested. The entire microgyroscope package is approximately 1/spl times/1/spl times/0.7 inches in dimensions. The rest of the control electronics which includes the drive and lock-in amplifier circuitry are mounted outside the gyro box on a 1/spl times/1 inch circuit board. This packaged microgyroscope has a 7 Hz split between its drive and sense mode and has a scale factor of 24 mV/deg/sec, bias stability of 70 deg/hr, angle random walk of 6.3 deg//spl radic/hr, and a rate ramp of 0.2 deg/hr/sec. Recent improvements on the fabrication and assembly procedures and microgyroscope design have resulted in clover-leaf structures with matched drive and sense resonant frequency. These new structures have a very small temperature dependent frequency shift of 0.23 Hz/degree for both the drive and sense modes.