Here is the abstract you requested from the IMAPS_2011 technical program page. This is the original abstract submitted by the author. Any changes to the technical content of the final manuscript published by IMAPS or the presentation that is given during the event is done by the author, not IMAPS.
|Vacuum Packaging for High-Performance Low Cost MEMS Gyro used in 6 Degrees of Freedom Inertial Navigation System|
|Keywords: Vacuum, Gyro, MEMS|
|Sensors in Motion Inc. is developing a navigation grade 6 DOF MEMS INS using its proprietary disc resonating gyroscope (DRG) structure. The military is investing in INS and Inertial Measurement Unit (IMU) technology which can answer its needs as well as provide the baseline for hundreds of other DOD and commercial applications which need C-swap (Cost, size, weight and power) sensitive utility. The DRG was conceived to address past problems associated with MEMS gyroscopes while leveraging the C-swap benefits of high volume, high yield batch fabrication, automated packaging, self-calibration, and thermal compensation. Prototypes yield noise measurements by Allan Variance analysis of 0.02 deg/hr Bias stability, 0.003 deg/sq-hour Angle Random Walk and a North finding error of RMS of 2 mils in 120 seconds. A key requirement for the DRG is controlled vacuum-levels in the sub-milli-Torr range to obtain high Q devices. Gyro die are packaged using a multilayer package and getter system, which provides and maintains sealed vacuum cavities. Die are assembled into the LCC package using conventional assembly techniques and the lid is sealed to the package using an SST 3150 high-vacuum sealing system. The SST system is used to activate a thin-film getter layer on the package lid before reflow of the solder seal. Resulting pressure levels have been determined by characterizing assembled but unlidded sensor die in a vacuum chamber. The package material, process flow and test results will be summarized and reviewed. Tooling, process parameters, and test techniques will be explained.|
Sensors in Motion, Inc.