Abstract
This paper presents the effect of BCB sealing ring flatness on BCB bonding for wafer-scale BCB cap transfer packaging. BCB sealing ring has shown partial bonding or full bonding depending on its flatness. It is found that the principal cause of the partial bonding is due to non-flat BCB sealing ring caused by multilayer BCB coating process. As a solution, BCB dry etching has been proposed to improve the flatness of the BCB sealing ring for full BCB bonding. Besides, partial bonding of BCB ring has been analyzed through FEM modeling of BCB cap with a non-flat sealing ring. The FEM model consists of Si carrier wafer, BCB cap, and Si target substrate. Unique load is applying pressure on top of Si carrier wafer like wafer-scale bonding. The role of applying pressure is to get BCB sealing ring to be contacted and expand bondable area with target Si substrate. As BCB sealing ring is bonded through BCB polymerization by holding the pressure for 1 h at 250 °C, mechanical properties of virgin BCB sealing ring has been changed during bonding. Thus, it has been chosen as variable for parametric analysis. Also, BCB cap dimension has been used as another parameter for the parametric analysis.
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References
Dow Chemical Company (2005) DS2100 puddle develop process, Processing procedures for CYCLOTENE 4000 series photo BCB resins
Giacomozzi F, Mulloni V, Colpo S, Faes A, Sordo G, Girardi S (2015) RF-MEMS packaging by using quartz caps and epoxy polymers. Microsyst Technol 21(9):1941–1948
Gong Z et al (2018) Wafer-level packaging method for RF MEMS applications using pre-patterned BCB polymer. Micromachines 9:93. https://doi.org/10.3390/mi9030093
Kim J, Seok S, Rolland N (2012) Polymer-based zero-level packaging technology for high frequency RF applications by wafer bonding/debonding technique using an anti-adhesion layer. Int J Precis Eng Manuf 13(10):1861–1867
Satyajit S et al (2006) Evaluation of die stress in MEMS packaging: experimental and theoretical approaches. IEEE Trans Compon Packag Technol 29(4):735–742
Seok S (2016) Fabrication and modeling of nitride thin film encapsulation based on anti-adhesion-assisted transfer technique and nitride/BCB bilayer wrinkling. IEEE Trans Compon Packag Manuf Technol 6(9):1301–1307
Seok S, Rolland N, Rolland P-A (2006) Packaging methodology for RF devices using a BCB membrane transfer technique. J Micromech Microeng 16(11):2384–2388
Seok S, Fryziel M, Rolland N, Rolland P-A (2012) Enhancement of bonding strength of packaging based on BCB bonding for RF devices. Microsyst Technol 18(12):2035–2039
Wang CH et al. (2008) Chip scale studies of BCB based polymer bonding for MEMS packaging. In: 58th Electronic components and technology conference
Wöhrmann M et al. (2011) Low temperature cure of BCB and the Influence on the mechanical stress. In: Electronic components and technology conference (ECTC), pp 392–400
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
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Seok, S. Experiment and analysis of the effect of BCB sealing ring flatness on BCB cap transfer packaging. Microsyst Technol 27, 263–268 (2021). https://doi.org/10.1007/s00542-020-04945-z
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DOI: https://doi.org/10.1007/s00542-020-04945-z