Packaging and Feedthrough Modes of Wafer Level for RF MEMS Switches

This paper reports on the methods, feedthrough modes and RF performance of wafer level packaging for RF MEMS switches. By analyzing the effects of packaging methods and feedthrough modes on the cost, weight, size, loss, RF performance and function of switches, a novel wafer level packaging structure which is performed using the wafer-level microencapsulation on the thin silicon substrate as the RF MEMS switches wafer with the vertical feedthroughs is presented. This structure has some advantages, such as low thickness, low parasitic capacity, short electric path, lightweight, no real ring and compatibility with the devices fabrication processes. Therefore, for RF applications, the packaging structure obviously reduces electric path loss and fabrication cost, and provides better RF performance of RF MEMS switches