Using MEMS to Build the Device and the Package

MEMS devices must be packaged to be used. Unfortunately, MEMS packages are challenging to develop, and the packaging of MEMS devices often dominates the cost of the product. In recent years, our group has worked with a team from Bosch to develop and demonstrate a novel wafer-scale encapsulation approach for MEMS. This process uses MEMS fabrication steps to build the device and the package at the same time. The main advantage of this approach is that the wafers emerge from the fabrication facility with all the fragile MEMS structures completely buried within the wafer, allowing all existing standard handling and packaging approaches, such as wafer-dicing, pick/place, and injection mold packaging to be used. This encapsulation process enables CMOS integration, embedding, and extreme miniaturization of complete systems. In this paper, we describe some advantages for performance, size and cost that can come from this approach.