Sacrificial microchannel sealing by glass‐frit reflow for chip scale atomic magnetometer

Abstract

AbstractA novel sealing technique using sacrificial microchannels was proposed for control of an atmosphere in a micromachined alkali metal vapor cell for a chip‐scale atomic magnetometer. The microchannels act as a feedthrough connecting the cell to the outside atmosphere during evacuation and gas filling steps, and eventually they are sealed by glass‐frit reflow. A silicon microchannel was designed and sealing by glass‐frit reflow was successfully demonstrated in reflow experiments. Simulation results clarified the glass‐frit reflow characteristics and their dependence on cross‐sectional shapes of the microchannels. Hermeticity of the proposed sealing technique at a leak rate of less than 10−12 Pa·m3/s was verified by a high‐resolution helium leak test. © 2013 Wiley Periodicals, Inc. Electron Comm Jpn, 96(5): 58–66, 2013; Published online in Wiley Online Library (wileyonlinelibrary.com). DOI 10.1002/ecj.10432