RF-MEMS devices packaging by using quartz caps and epoxy polymer sealing rings

This work reports on RF MEMS chip capping to protect sensitive devices by quartz caps having a cavity to enclose MEMS devices and an epoxy dry film polymer as a sealing ring. The fabrication process for both die-to-die and wafer-to-wafer 0-level capping is presented. Good adhesion of caps to the substrate is demonstrated by shear tests, while RF measurements on CPW lines indicate a negligible insertion loss increase. Capping of both capacitive and ohmic switches is reported showing no loss of functionality but a modification of actuation voltage induced by thermal treatment.