Four-point SC-cut crystal unit design calculations for reduced acceleration sensitivity

Efforts have been directed toward development of a readily manufacturable four point mount which minimizes acceleration sensitivity for 10 MHz, 3rd, SC-cut crystal units. Design criteria have been established for the mounts to improve crystal unit precision and reduce acceleration sensitivity. A four point mount, called the horizontal strip mount, satisfies the design criteria. Lower acceleration sensitivities are predicted for the horizontal strip mount design, and optimum mode locations are in closer proximity to the resonator center over all mount orientations. Calculations have been performed which characterize variations in acceleration sensitivity with changes in critical dimensions for the horizontal strip mount. Optimum mount dimensions which minimize acceleration sensitivity have been calculated.<>