Packaging for MEMS devices - Stumbling block or enabling solution?

MEMS devices may exhibit delicate structures sensitive to damage during handling or environmental influences. Their functionality may furthermore depend on sealing out the ambient or being in direct contact. Stress, thermal load or contaminations may change their characteristics. Here packaging technology is challenged to extend from microelectronics towards MEMS and MOEMS. Today's approaches typically rely on housing the miniature devices in bulky ceramic or metal casing or -putting them into very high volume production-, benefiting from the microelectronics packaging infrastructure. Alternatively, besides focusing on available technology, device manufacturers develop individual packages for their product - typically at high cost. While there is nowadays a good infrastructure for MEMS realization from universities to MEMS foundries, packaging still remains as a bottleneck at the end of the design cycle, sometimes stopping a device from being commercialized. Selecting t he proper packaging method may tip the scale towards a product success and a product failure. Choosing the right technology therefore is not only a marginal work package but a crucial part of the product design. Three approaches to be applied for MEMS/MOEMS devices will be presented and highlighted by examples. Single die packaging, die-to-wafer processes as well as wafer level packaging options are detailed with their individual benefits and challenges. Mechanical, fluidic and optical aspects are reflected in the package technologies selected for the individual examples presented. Accelerated testing of the packaged devices under actual conditions may also be a stumbling block, one example on an optical microsystem will showcase this issue, highlighting system response under different environmental loads