Novel MEMS CSP to bridge the gap between development and manufacturing

MEMS packaging plays an important role within the function of the MEMS device. Besides the electrical interconnection, the package provides mechanical protection. It must enable the resulting package to be manufactured and assembled at low cost. Also, high reliability requirements even under harsh conditions must be fulfilled in order to be accepted in the market. Capping and hermetic sealing of MEMS devices is a key factor in enabling them to be processed with further packaging steps. Instead of developing for each device an adapted packaging process, there is a requirement to provide a technology platform that enables a fast, low cost processing of protected devices. Wirebonding can be used to overcome the 3D wiring issues and provide a fast and mature process with a well established infrastructure to realize packaged MEMS devices with minimal dimensions. Solder balls terminate the electrical interconnects, allowing a seamless integration into a SMD compatible process. This paper presents the concept, the technical realization of this approach and the extension to a full wafer level chip scale MEMS package.