Abstract
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 film polymer as a sealing ring. Full hermeticity is not possible due to the permeability of polymer but the goal to protect the mobile parts of the devices during dicing and assembling was achieved. Good RF MEMS devices are produced by die-to-die bonding and a reliable fabrication process is defined while wafer-to-wafer process still needs improvement to increase the fabrication yield. In this paper 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 contact switches is reported showing no loss of functionality but a modification of actuation voltage induced by thermal treatment.
Similar content being viewed by others
References
Baumgartner T, Hauck K, Topper M et al (2010) Dry film photo resists and polymers—the low cost option for standard and 3-D wafer level packaging. In: 11th International Conference on Electronic Packaging Technology and High Density Packaging (ICEPT-HDP), Xi’an, China, 16–19 Aug, 2010, pp 50–54
Esashi M (2008) Wafer level packaging of MEMS. J Micromech Microeng 18:073001. doi:10.1088/0960-1317/18/7/073001
Giacomozzi F, Mulloni V, Colpo S, Iannacci J, Margesin B, Faes A (2011) A flexible fabrication process for RF-MEMS devices. Romanian J Inf Sci Technol 14(3):259–268
Jourdain A, De Moor P, Baert K, DeWolf I, Tilmans HAC (2005) Mechanical and electrical characterization of BCB as a bond and seal material for cavities housing (RF-) MEMS devices. J Micromech Microeng 15(2005):S89–S96. doi:10.1088/0960-1317/15/7/013
Kim J, Seok S, Sharma P, Rolland N, Rolland PA (2011) Low loss zero-level packaging for high frequency RF applications by using PerMX dry film photoresist. In: 41st European Microwave Conference, Manchester, 10–13 Oct 2011
Niklaus F, Stemme G, Lu JQ, Gutmann RJ (2006) Adhesive wafer bonding. J Appl Phys 99:031101
Rebeiz GM (2003) RF MEMS: theory, design, and technology. Wiley, Hoboken
Tilmans HAC (2002) MEMS components for wireless communications. In: 16th European Conference on Solid-State Transducers EUROSENSORS, 15–18 Sept, 2002, Prague
Töpper M, Fischer T, Baumgartner T, Reichl H (2010) A comparison of thin film polymers for wafer level packaging. In: Proceedings of 60th electronic components and technology conference (ECTC), Las Vegas, NV, USA 1–4 June 2010, pp 769–776
Zine-El-Abidine I, Okoniewski M (2009) A low-temperature SU-8 based wafer-level hermetic packaging for MEMS devices. IEEE Trans Adv Packag 32(2):448–452
Acknowledgments
This work has been supported by ARASCOM and MEMSPACK EU projects. The authors would like to thank the staff of FBK MT-Lab for the support in the fabrication of the RF-MEMS devices.
Author information
Authors and Affiliations
Corresponding author
Rights and permissions
About this article
Cite this article
Giacomozzi, F., Mulloni, V., Colpo, S. et al. RF-MEMS packaging by using quartz caps and epoxy polymers. Microsyst Technol 21, 1941–1948 (2015). https://doi.org/10.1007/s00542-014-2256-y
Received:
Accepted:
Published:
Issue Date:
DOI: https://doi.org/10.1007/s00542-014-2256-y