Microelectromechanical systems (or its popular acronym, MEMS) is a term that was officially coined over two decades ago. It has since generated a great deal of interest as well as expectations in the scientific and engineering communities. Many perceived the microsystems technology (MST) that produces MEMS as the driver of an imminent new industrial revolution that would fundamentally change the way the industry functions from early conceptual design to the production of end products. While many new products such as smart sensors and precision biochemical analytic systems have been developed and successfully integrated in automotive and biomedical products, many of the early expectations for full commercialisation of a great many MEMS and microsystems have not materialised.

There are a number of factors that have contributed to the inauspicious outcome of commercialising MEMS and microsystems. One such factor is the extreme complexity of MST that involves theories and principles across multiple disciplines of science and engineering. The high diversity of MST products that has led to the lack of standardisation in design, manufacture and production is another possible reason. Critical contributing factors, however, are the cumbersome techniques that industries have used in packaging and assembling these products. A special report by the US National Research Council (NMAB-483) in 1997 appropriately expanded the scope of MEMS packaging to APT, an abbreviation of Assembly, Packaging and Testing . Indeed, APT has been a major cost factor in almost all MEMS and microsystems products. For example, the cost of APT varies from a moderate 20%...