QUARTZ CRYSTAL AGING EFFECTS.
Abstract
The purpose of this research is to improve fabricating procedures and reduce the aging of quartz resonators. Aluminum-plated 5 MHz resonators in the HC-27/U container displayed high negative aging rates when stored at 45C. Successive aging at 45C and 85C revealed the source of the aging to be absorbed vapors or gases. Resonators plated in an ion-pumped vacuum exhibited reduced aging. In aging studies of 5 MHz aluminum-plated resonators at 85C, improved aging resulted from plating the units and sealing them in cold-welded holders in an oil-free vacuum. Units baked 60 minutes at 125C before sealing had a negative aging vector but after baking 120 minutes at 125C before sealing the aging vector was positive. After two weeks the aging rates were about +2 x 10 to the minus 9th power/wk. A comparison of 5 MHz AT-cut resonators of cultured, swept-cultured, high-Q cultured, and natural quartz, using the annular electrode configuration, revealed aging rates of 1 x 10 to the minus 9th power/wk., 1.5 x 10 to the minus 9th power/wk., 2.1 x 10 to the minus 9th power/wk., and 2.4 x 10 to the minus 9th power/wk. respectively for the last ten weeks of a 27 week period. A comparison of defect incidence in resonators displaying low aging and those displaying anomalous aging, activity dips, or other undesirable behavior is underway. (Author)
Document Details
- Document Type
- Technical Report
- Publication Date
- May 01, 1968
- Accession Number
- AD0834478
Entities
People
- R. B. Belser
- W. H. Hicklin
Organizations
- Georgia Tech