Office of Technology Transfer – University of Michigan

Wafer-Level Vacuum Packaging Technology for MEMS

Technology #2457

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Categories
Researchers
Khalil Najafi
Managed By
Joohee Kim
Licensing Specialist, Physical Sciences & Engineering 734.764.8202
Patent Protection
US Patent 7,098,117

Background

Low-cost vacuum packaging has become one of the most important challenges in the MEMS industry for a number of emerging applications including resonant sensors and radiofrequency MEMS. Some essential features of a MEMS package include small size, vacuum/ hermetic capability, integrated sealed feedthroughs, wafer level processing, stability in harsh environmental conditions, and low cost. Simultaneously meeting all of these criteria is a challenge in the field of MEMS sensors and microsystems.

Technology

Researchers at the University of Michigan have developed a low-cost manufacturing method for vacuum or hermetically packaged micromachined device with vertical feedthrough wherein a minimum amount of die area is used. In this process, the MEMS device is fabricated in a conventional fashion with p++ layers bonded to a glass substrate. The electrical connections are formed by using metal lines on glass, where a combination layer of Ti/ Pt/ Au is typically used (Au on top layer). The feedthroughs are substantially vertical and are formed through the glass substrate.

Applications and Advantages

Applications

  • Vacuum and/or hermetic packaging and feedthrough technology for micromachined or MEMS devices such as DWP sensors, in particular for vibratory gyroscopes

Advantages

  • Low susceptibility to damage
  • Minimal die area consumed
  • Easily formatted for surface mount applications
  • Wafer level procedure with standard processing
  • Process can be performed after MEMS-nl-fabrication