Miniaturised integrated hybrid microsystem assemblies for harsh environment applications

There is a growing requirement for distributed sensors to measure, monitor and control systems such as airframes, wind turbines, engines, power trains, human motion and seismic sensors. These type of devices need to be as unobtrusive as possible and miniaturisation of the sensor and its control circuitry is a key factor in achieving this. This paper reports on a method of combining the sensor element and the control electronics in a single hybrid packaged unit which can provide a step decrease in the size of the component. The manufacturing processes developed within the project have addressed a rugged vacuum compatible package environment with co-located control electronics. For microsystem encapsulation, wafer level metal sealing techniques have been realised through bonding of the multi-sensor device to a silicon capping/interconnect wafer. The connections from the multi-sensor device have been designed using through silicon vias (TSV). An application specific integrated circuit (ASIC) has been designed and manufactured to provide the control electronics for the multi-sensor device and this has been connected through to the multi-sensor device using solder bump technology. The ASIC has also been designed to accommodate decoupling capacitors to minimise signal noise and parasitics and a flexible circuit to provide connections. The demonstration unit has a size of <;10mm × 10mm, which is a 15X reduction in size compared to equivalent packaged units. The approach developed within the project has potential in applications for inertial measurement and also for microsystems involving fluidic and optical components.