Development of a second generation low cost MEMS gyroscope: design for manufacture

The successful development of a MEMS gyroscope, targeted at high volume, low cost applications, requires careful consideration of both the design and the fabrication requirements. It is essential that the design requirements (e.g. dimensional tolerances) are comfortably within the process capabilities in order to maximise yield at each step. This becomes increasingly important as the design becomes more complex, for instance: with the inclusion of wafer level vacuum encapsulation or the integration of electronics directly onto the device layer silicon. The practical implications of this design for manufacture (DFM) approach are discussed as applied to the BAE systems second generation silicon MEMS gyro. Specific features of the resultant sensor design are described in detail.