Microsystems such as accelerometers, gyroscopes and detectors are making a significant impact to a wide range of industries.

The microsystems contain micro-machined features on silicon, ceramics or polymers which are closely spaced. Any contamination, moisture or even gases can adversely affect the performance of these structures. Significant attention has been focused on the development of micro-machining technologies. However, less consideration has been given to the packaging of these devices to meet performance, environmental and cost constraints.

Some microsystems can be satisfactorily housed within conventional electronic packages. Others have exceptional packaging demands - e.g. operation in vacuum for 10 years.

GE Aviation has been working on examining the factors influencing the selection of the most appropriate packaging route for several microsystem devices, the critical areas being:

• Microsystem partitioning

• Lifetime of package seals

• Lifetime of leadthrough seals (e.g. glass to metal seals)

• Minimisation of material outgassing and ingress from the environment

• Integration of windows (e.g. infra-red)