| AVS 60th International Symposium and Exhibition | |
| Vacuum Technology | Monday Sessions |
| Session VT-MoA |
| Session: | Dynamic Vacuum Processes and Outgassing |
| Presenter: | R.S. Goeke, Sandia National Laboratories |
| Authors: | R.S. Goeke, Sandia National Laboratories S.X. Dai, Sandia National Laboratories R.K. Grubbs, Sandia National Laboratories |
| Correspondent: | Click to Email |
Commercial low temperature cofired ceramic (LTCC) technology is established in microelectronics and microsystems packaging, multichip and radio frequency (RF) modules, and sensors. The ability to combine structural considerations with embedded traces and components using laminated glass-ceramic tapes has created solutions to unconventional packaging requirements of micro-electro-mechanical systems (MEMS) devices. Many MEMS devices such as resonators are very sensitive to pressure and require packaging in a vacuum environment. Attaining and maintaining desirable pressure levels in sealed vacuum packages requires knowledge of the permeation characteristics of the vacuum envelope and the sealing materials.
An experimental system to measure the time dependent gas permeation through LTCC at temperatures from room temperature to 500°C has been developed. This system utilizes a membrane technique in which a gas is allowed to permeate through a test sample, held at a constant temperature, into a high vacuum chamber where it is detected using a mass spectrometer. The gas permeation value is determined from the steady state gas flux through the sample. The gas diffusivity and solubility in the material were calculated using data from the time dependent approach to the steady state condition. The gas-solid permeation data for helium and hydrogen through DuPont 951 and 9K7 LTCC will be presented and compared to the permeation through other common vacuum envelope materials such as glasses and high-purity alumina ceramics. Application of the permeation data to the prediction of vacuum levels inside hermetic LTCC packaged devices will be discussed. This data can further be utilized in designs to create LTCC packages that meet specific pressure/time operating requirements.
Sandia National Laboratories is a multi-program laboratory managed and operated by Sandia Corporation, a wholly owned subsidiary of Lockheed Martin Corporation, for the U.S. Department of Energy's National Nuclear Security Administration under contract DE-AC04-94AL85000