Micro Crystal AG

The interest for high frequency fundamental (HFF) quartz crystals is soaring up in the fields of telecommunications and instrumentation.High speed communication systems require high frequency references and fundamental mode resonators have preference when either a large pulling range, a large bandwidth or a low spurious level in the spectrum are required.Micro crystal has developed a manufacturing process combining photolithog. batch technol. and wet chem. local thinning on wafer.Thus, it is possible to produce HFF rectangular AT resonators with inverted mesa structure in large quantities and at reduced labor cost.A crystal was designed at 50 MHz (membrane thickness 33 μm) and sufficient quantities are being produced for technol. characterization and assessment.The AT-HFF resonator is robust due to single ended rigid mounting and encapsulation in a hermetically sealed SMD ceramic package (8 × 3.6 × 1.8mm³).Elec., thermal and environmental characteristics of this type of quartz crystals are presented.