Microcomponent assembly and packagingMicroengineered devices have the potential to be as inexpensive as silicon chips are today. This, however, will only be true when two conditions are met: 1) the fabrication process has a high yield (most of the devices on a wafer function properly, and will continue to do so after packaging); and 2) batch processing techniques are used for as much of the process as possible (i.e. large numbers of devices per silicon wafer, and a large number of wafers are processed at the same time at each fabrication step).When developing microengineered devices, and with complicated microsystems, it is difficult to achieve high yields. However these must be achieved before putting the device into production, with few exceptions. If the device does something that is very important, and cannot be done any other way, then perhaps a low yield and expensive devices can be justified. Assembling complex devices from many microscopic parts and, in particular, packaging these devices so they can be handled and connected to other components / systems, will generally involve handling the devices individually. This can add significantly to the cost of the finished part (tens to hundreds of times the cost of the actual active part of the device - depending on the complexity and requirements of packaging). Consequently the assembly and packaging of devices for commercial manufacture has to be carefully considered. |