Temperature insensitive piezoelectric crystal mounting arrangement

Claim 1

A piezoelectric crystal mounting arrangement comprising: a substrate of electrically insulative material; an AT cut piezoelectric crystal plate having a center and opposed upper and lower surfaces with at least one electrode disposed on the upper surface of said crystal plate and at least one electrode disposed on the lower surface of said crystal plate, said crystal plate exhibiting X, Y, and Z reference coordinate axes, and four support pedestals, each pedestal being situated on said substrate and being oriented so as to contact and support said crystal plate along a respective one of four axes of said crystal plate situated at angles of approximately 60°, 120°, 240°, and 300° with respect to the X axis of said crystal plate, the angle of each of said axes being selected to minimize stress exerted on said crystal plate by the differential thermal expansion of said crystal plate with respect to said substrate and pedestals, said four pedestals being substantially centrally situated on said crystal plate, said four pedestals being arranged on said substrate so as to form the four corners of a four-sided polygon, the center of said crystal plate being situated above and laterally within said four-sided polygon formed by said pedestals.