Critical challenges in packaging MEMS devices

This paper reviews several current MEMS based products and highlights the critical packaging challenges for these devices. Several package configurations are shown, and issues around processing, material selection, and particle control are discussed. The package configurations are divided into three main groups: cavity packages, plastic molded packages, and wafer level packages. Several alternate process flows for these package types are reviewed, and the advantages and disadvantages of each flow are highlighted. Wafer bonding processes and anti-stiction measures are covered in some detail, since they are critical to many of the package configurations. The practice of silicone gel coating as a method of encapsulating MEMS devices is also discussed