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Analytical investigation of the feasibility of sacrificial microchannel sealing for Chip-Scale Atomic Magnetometers

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Abstract

An alkali metal vapor cell is a crucial component of the highly sensitive Chip Scale Atomic Magnetometers (CSAMs) that are increasingly deployed in a variety of electronic devices. Herein, we propose a novel microfabrication technique utilizing an array of microchannels at a bonded interface, to enable gas feedthrough for evacuation of unwanted gases from a vapor cell and subsequent introduction of an inert gas, followed by permanent sealing of the microchannels by reflow of a glass frit. The characteristics of glass frit reflow are analyzed to investigate the feasibility of using microchannels formed either on a silicon substrate, or embedded in a glass frit layer, with four different cross-sectional shapes considered. Prior to modeling the microchannels for simulation, the minimum cross-sectional size of a microchannel that fulfills gas feedthrough requirements was calculated and a value of 10 μm was determined based on a flow conductance model. The sealing of the microchannels was simulated using the finite element method (FEM) and the results revealed that flow resistance is a crucial design factor. Thus, embedded microchannel designs were more suitable for the proposed sealing technique than microchannel designs fabricated in silicon.

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Acknowledgments

This work was partly supported by the Innovative Techno-Hub for Integrated Medical Bio-imaging of the Project for Developing Innovation Systems, from the Ministry of Education, Culture, Sports, Science and Technology (MEXT), Japan.

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Authors and Affiliations

  1. Nano/Micro System Laboratory, Department of Micro Engineering, Kyoto University, Kyoto, Japan

    Kazuya Tsujimoto, Yoshikazu Hirai, Koji Sugano, Toshiyuki Tsuchiya & Osamu Tabata

Authors
  1. Kazuya Tsujimoto
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  2. Yoshikazu Hirai
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  3. Koji Sugano
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  4. Toshiyuki Tsuchiya
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  5. Osamu Tabata
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Correspondence to Kazuya Tsujimoto.

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Tsujimoto, K., Hirai, Y., Sugano, K. et al. Analytical investigation of the feasibility of sacrificial microchannel sealing for Chip-Scale Atomic Magnetometers. Microsyst Technol 20, 357–365 (2014). https://doi.org/10.1007/s00542-013-1895-8

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  • DOI: https://doi.org/10.1007/s00542-013-1895-8

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