Design and Fabrication of Wafer-Level Package for RF MEMS Switch Using BCB
RF MEMS devices like switches are made up of movable fragile structures that need to be encapsulated in microcavities to protect them from contamination or damage during the subsequent wafer dicing and packaging process steps. This packaging method is referred to as wafer-level or zero- level packaging and enables the whole MEMS wafer to be packaged in the controlled environment of the clean room. This paper reports the design and fabrication of a packaging solution based on micromachined high resistivity silicon and BCB sealing. Theoretical studies have been carried out to study the effects of the cavity height and the width of the BCB sealing ring on the coplanar transmission line up to 40 GHz. Fabrication of the package has been demonstrated and RF measurements have been done on a 50 Ω line to validate the simulations. It is found that BCB has a negligible effect on the insertion loss of the CPW line.
KeywordsAdhesive bonding Wafer-level packaging Benzocyclobutene (BCB)
I would like to thank Director SSPL for his cooperation and guidance in carrying out this research work.