Wafer Level Thin Film Encapsulation for MEMS

Abstract

Because they have moving parts, or because they need to work in a specific atmosphere (vacuum, inert gas,...), microelectromechanical systems (MEMS) are not compatible with standard integrated circuit (IC) packaging technologies. Specific packaging needs represent a great part of the final manufacturing cost of such devices. This article presents a solution to encapsulate RF MEMS devices in hermetically sealed cavities, using only standard IC manufacturing technologies at wafer level. This thin film pre-packaging process enables MEMS protection and greatly reduces the cost of final packaging. Compatibility of thin film packaging with standard IC packaging technology is studied