All quartz surface mount resonators

This paper presents the electrical and mechanical characteristics of high frequency "all-quartz" surface mount resonators. All-quartz surface mount resonators are fabricated using a suitably electroded quartz crystal base plate and a cover plate of quartz which are bonded to a specially formed, electroded AT-cut quartz resonator plate with epoxy resin to create a hermetic seal. Methods of production have been developed which allow for the manufacture of this type of resonators having fundamental mode frequencies in the range from 3.5 MHz to more than 50 MHz. The paper presents the results of aging and environmental studies, that show that the frequency stability, equivalent series resistance and other electrical properties of the all-quartz surface mount resonators are equivalent to the values of the same parameters of quartz resonators which are encapsulated in SMT ceramic enclosures. However, the dimensions of the all-quartz surface mount resonators have a much lower height and smaller volume and they exhibit substantially greater resistance to shock and vibration than the ceramic enclosed resonators of the same frequency.