High temperature MEMS packages: die-attach solutions for LiNbO3 under low bonding pressures
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A survey of high temperature die-attach solutions for lithium niobate (LiNbO3) single crystals was conducted and based on that three promising approaches; i.e. eutectic solder, silver sinter-paste and silver-loaded conductive adhesive; were proposed and investigated. A relatively low pressure span (0–4 MPa) was employed, aiming to mitigate the risk of fracture in the brittle die. The mechanical properties of the corresponding die-attach assemblies was examined by a die-shear tester and the reliability of the joints was assessed after isothermal aging at 300 °C. The micro-structural integrity of the bonding was also analyzed by cross-sectional microscopy. The results revealed that silver sinter paste die-attach possesses superior shear strength in comparison to the two other techniques. Cross-sectional failure analysis also indicated a ductile fracture mode throughout the bonding layer for silver-paste and adhesive joints, whereas in soldered assemblies a brittle fracture mode along the interfacial intermetallic compound layer was predominant.
KeywordsShear Strength Lithium Niobate Conductive Adhesive Eutectic Solder Lithium Niobate
This project has been supported by the COMET K1 center ASSIC (Austrian Smart Systems Integration Research Center). The COMET (Competence Centers for Excellent Technologies) Program is supported by BMVIT, BMWFW and the federal provinces of Carinthia and Styria. SEM investigations were carried out using the facilities at the University Service Center for Transmission Electron Microscopy at the Vienna University of Technology.
- 1.J.H. Lau et al., Advanced MEMS packaging. (McGraw-Hill, New York, 2010)Google Scholar
- 2.G.R. Blackwell ed., The electronic packaging handbook. Vol. 4. (CRC Press, Boca Raton, 1999)Google Scholar
- 4.K. Geshi et al., “Wafer bonding of polycrystalline spinel with LiNbO 3/LiTaO 3 for temperature compensation of RF surface acoustic wave devices.” 2012 IEEE International ultrasonics symposium. IEEE, (2012)Google Scholar
- 6.K.K. Wong, Properties of lithium niobate (No. 28) IET (2002)Google Scholar
- 12.T. Zhou, T. Bobal, M. Oud, J. Songliang, Au/Sn solder alloy and its applications in electronics packaging. (Coining Inc, 1999)Google Scholar
- 15.M. Knoerr, A. Schletz, “Power semiconductor joining through sintering of silver nanoparticles: evaluation of influence of parameters time, temperature and pressure on density, strength and reliability.” Integrated Power Electronics Systems (CIPS), 2010 6th International Conference on. IEEE, 2010Google Scholar
- 17.MIL-STD-883E, Test method standard—Microcircuits, USA, 1996)Google Scholar
- 19.Aremco Pyroduct 597-A, Aremco Products Inc., Valley Cottage, NY.Google Scholar