Wafer Level Hermetic Packaging for RF-MEMS Devices Using Electroplated Gold Layers

Abstract

Thermocompression bonding of electroplated gold is a promising technique for achieving low temperature, wafer level hermetic bonding without the application of an electric field or high temperature. Silicon wafers were completely bonded at 320 at a pressure of 2.5. The interconnection between the packaged devices and external terminal did not need metal filling and was made by gold films deposited on the sidewall of the via-hole. In the hermeticity test, packaged wafers had the leak rate of 2.74 ± 0.61 × 10-11 Pa m3/s. In the result of application in packaging of FBAR filter, the insertion loss is increased from -0.75dB to -1.09dB at 1.9.