Abstract
Development of packaging is one of the critical issues toward realizing commercialization of radio-frequency-microelectromechanical system (RF-MEMS) devices. The RF-MEMS package should be designed to have small size, hermetic protection, good RF performance, and high reliability. In addition, packaging should be conducted at sufficiently low temperature. In this paper, a low-temperature hermetic wafer level packaging scheme for the RF-MEMS devices is presented. For hermetic sealing, Au-Sn eutectic bonding technology at temperatures below 300°C is used. Au-Sn multilayer metallization with a square loop of 70 µm in width is performed. The electrical feed-through is achieved by the vertical through-hole via filling with electroplated Cu. The size of the MEMS package is 1 mm × 1 mm × 700 µm. The shear strength and hermeticity of the package satisfies the requirements of MIL-STD-883F. Any organic gases or contamination are not observed inside the package. The total insertion loss for the packaging is 0.075 dB at 2 GHz. Furthermore, the robustness of the package is demonstrated by observing no performance degradation and physical damage of the package after several reliability tests.
This is a preview of subscription content, log in via an institution to check access.
Similar content being viewed by others
References
V. Varadan, K. Vinoy, and K. Jose, RF MEMS and Their Application (New York: John Wiley & Sons, Ltd., 2003).
P. Wilkerson et al., Microelectromechanical Systems Conf. (Piscataway, NJ: IEEE, 2001), pp. 91–94.
T.H. Lih, L.D.J. Li, and M.K. Shun, 52nd ECTC Proc. (Piscataway, NJ: IEEE, 2002), pp. 1032–1036.
L. Mercado, S. Kuo, T.Y. Lee, and R. Lee, IEEE Trans. Adv. Packaging 28, 34 (2005).
G. Li, A. Tseng, IEEE Trans. Electron. Packaging Manufacturing 24, 18 (2001).
R. Gooch and T. Schimert, MRS Bull. 28, 55 (2003).
W.H. Ko, J.T. Suminto, and G.J. Yeh, Micromachining and Micropackaging of Transducers (Amsterdam: Elsevier, 1985), pp. 41–61.
F. Niklaus et al., J. Micromech. Microeng. 11, 100 (2001).
A. Gerlach et al., Microsystem Technol. 5, 144 (1999).
T. Itoh, H. Okada, H. Takagi, R. Maeda, and T. Suga, The 12th Int. Conf. on Solid States Sensors, Actuators and Microsystems (Boston, MA: Transducers, 2003), pp. 1828–1831.
Y.T. Cheng, L. Lin, and K. Najafi, J. Microelectromech. S. 9, 3 (2000).
G. Tsau, S. Spearing, and M. Schmidt, J. Microelectromech. S. 11, 641 (2002).
D. Ivey, Micron 29, 281 (1998).
C. Wang and C. Lee, 42nd ECTC Proc. (Piscataway, NJ: IEEE, 1992), pp. 502–507.
H. Okamoto and T.B. Massalski, Phase Diagram of Binary Gold Alloys (Metals Park, OH: ASM International, 1987), pp. 278–289.
G.S. Matijasevic, C.C. Lee, and C.Y. Wang, Thin Solid Films 223, 276 (1993).
S. Burkett, X. Qiao, D. Temple, B. Stoner, and G. McGuire, J. Vac. Sci. Technol., B 22, 248 (2004).
A. Kohno, Y. Sasaki, R. Udo, T. Harada, and M. Usami, J. Micromech. Microeng. 11, 481 (2001).
S. Mack, H. Baumann, U. Gösele, H. Werner, and R. Schlögl, J. Electrochem. 144, 1106 (1997).
A. Roth, Vacuum Technology (Netherland: North-Holland Publishing, 1976).
Y.T. Cheng, W. Hsu, K. Najafi, T.C. Clark, Nguyen, and L. Lin, J. Microelectromech. S. 11, 556 (2002).
Author information
Authors and Affiliations
Rights and permissions
About this article
Cite this article
Wang, Q., Choa, SH., Kim, W. et al. Application of Au-Sn eutectic bonding in hermetic radio-frequency microelectromechanical system wafer level packaging. J. Electron. Mater. 35, 425–432 (2006). https://doi.org/10.1007/BF02690529
Received:
Accepted:
Issue Date:
DOI: https://doi.org/10.1007/BF02690529