Lattice damages in quartz crystal blanks influence on the resonator properties and on the X-ray measurement

The temperature-frequency behavior of quartz crystals depends on the as-grown lattice defects in the volume as well as on process-induced surface damage. The influence of some special lattice distortions on the vibration behavior is calculated, assuming some simplified models. The degree of lattice damage is measured on blanks of different manufacturers and after different surface processing by means of the X-ray Θ-scan and Ω-scan methods. Single grains in the measuring area as well as reflection curve broadening and intensity changes are detected. It is necessary to check the lattice damage in blanks before further production steps in order to avoid crystal losses due to such damage. The curve-width and intensity measurement can be combined with automatic cut angle sorting, and the corresponding values can be used as additional sorting criteria.